microsoft word 130-133_212 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.130-133 https://doi.org/10.37868/dss.v3.id212 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 130 analysis of importance priority to be studied on igniter system of 450 caliber x rocket a. zaldiansyah1*, n. widianto2, y. h. yogaswara3, y. ruyat4 1,2,3,4 faculty of defense technology, indonesia defense university, indonesia *corresponding author e-mail: zaldi.msn@gmail.com received: nov. 28, 2022 revised: dec. 29, 2022 accepted: dec. 30, 2022 online: dec. 31, 2022 abstract a rocket is a flying platform that gets energy from the combustion process and performs a thrust that is large enough to reach hypersonic speed. it becomes quite vital considering the speed of the combustion process in double configuration propellant type, which is r=7 mm/s. the ignition of the propellant is supported by a squib as a conductor of electricity to the igniter which will then conduct heat to the propellant in the rocket motor. the main focus of this research is to analyze the development potential in the x rocket igniter system. this research uses a quantitative method approach, with the research analysis using a quality function deployment (qfd) approach. based on the benchmark values obtained from each supporting instrument used in the 450 caliber x rocket igniter system, the results were obtained on a priority scale for the development of a rocket igniter system as an effort to overcome the igniter from malfunctions when the operating system is running. the results show that the instruments that need to be developed are the squib, pyrotechnics, emergency button, ground system and wiring system. © the author 2022. published by arda. keywords: rocket, igniter system, qfd, malfunction, instrument. 1. introduction today, the development of military technology is increasingly being intensified. in indonesia, it has a road map of seven national priority programs related to weapons technology. [1] the road map contains seven priority programs for the national defense industry, including rockets and propellants which are one of the main focuses in research and development. there is ongoing research, namely the r han 450 mm rocket which is deemed necessary and requires a lot of research in its development. procurement of missiles and rocket is an important stage, in order to fulfil a minimum basic strength or known as minimum essential force (mef) in indonesia. [2] a rocket is a flying platform that gets energy from the combustion process and performs a thrust. [3] the resulting force is also large enough to reach hypersonic speed so that the reactive impulse will be proportional to the reaction, this is in accordance with newton's third law of motion. [4] based on research by ganda samosir in 2011 on the propulsion of rx.320 rocket, [5] although it has a high flash point, this is quite vital considering the speed of the combustion process in double configuration propellant type, which is r=7 mm/s. the ignition of the propellant is supported by a squib as a conductor of electricity to the igniter which conducts heat to the propellant in the rocket motor. [6] squib is part of the igniter of a rocket motor to ignite by electric a primary composition of the squib and some pyrotechnics. squib is an electric ignition wick. [7] depend on the speed of electricity flow on the squib, efforts are needed in conditioning the flow of electricity contained in the squib, so that an igniter can avoid dss vol. 3, 2022, pp.130-133 131 static electricity and unwanted disturbances. therefore, there is a need to analyze the importance priority to be studied on of the rocket igniter system to avoid malfunctions of the system. 2. research method this research was conducted using a quantitative method approach using a quality function deployment (qfd) method. qfd is a method to transform qualitative user demands into quantitative parameters, the user requirements data that has been obtained is interpreted to find relationships and interrelationships between existing data descriptions. [8] thus, the data is obtained in the form of scores on the design characteristics of each instrument, and a priority scale is obtained. 3. results and discussions 3.1. user requirements user requirements explain the needs desired by users who in this study are the firing igniter team from the rocket technology center (pustekroket) brin in indonesia. in this operation, there are several main points of user requirements that are desired for the purposes of the igniter system, which refers to the x rocket as outlined in the list of requirements (lor), as follows. table 1. list of requirements (lor) instruments user requirements urgency power supply electric current requirement of 1 ampere and voltage requirement of 20 volt 4 switch connector an emergency system is needed in the electrical panel box to be able to immediately cut off the current when something unexpected happens 5 cable proper cable are needed for 1 ampere and 20 volts, and have low resistance so that the time delay in igniter operation can be cut 4 grounding the grounding system required when operating the igniter is integrated with the firing system, and is expected to have a minimal resistance value, so that the static electricity contained in the wiring can be wasted towards ground 3 casing the main casing needs are the melting point of 600°c, the distribution of combustion is even, and the casing melts instantly 5 squib it takes a squib that has a long shelf life, and is not easily oxidized at room temperature 3 squib explosives requires high calorific value, low flameability 4 propellant material it requires a high calorific value, with the same flameability as that produced by an igniter flame 4 igniter explosives requires high calorific value, low flameability 4 description for table 1: • score 1: not important. • score 2: less important. • score 3: quite important. • score 4: high importance. • score 5: very high importance. based on the table above, data on user requirements related to the igniter system are obtained according to user interviews. the points of need are discussed for each component, in order to make it easier for the author to classify needs and their level of importance. dss vol. 3, 2022, pp.130-133 132 3.2. benchmark instruments based on table 1 list of requirements (lor), then the relation matrix stage is carried out. where the relation matrix is the match between the lor points and the processing of the design characteristics made. there are 2 processes at this stage, namely providing benchmark values, and a priority scale of design characteristics, to determine the development potential of each instrument supporting the igniter system on the x rocket. in making the relation matrix, there is a level of conformity that is divided into 3 with descriptions of weak linkage (1), moderate correlation (3), and high correlation (9). the relationship matrix was created to determine the relationship between the level of conformity between user needs and the characteristics of the design made. this criterion is based on the lor compiled and analyzed using quality function deployment (qfd). then the relationship between user requirements (list of requirements) and design characteristics is arranged in a relation matrix. the following relationship data are shown in table 2. table 2. relation matrix description of table 2: a. score 1: weak relationship. b. score 3: medium relationship. c. score 9: high relationship. based on table 2. relation matrix and performance benchmarks, the values that have priority scale numbers 1 and 2 are squib with 70.11%, and pyrotechnics with 69.35%. there are also emergency buttons, cables and ground that have a priority scale value of 3, 4, and 5, each of which has a value of 60.9%, 60.15%, and 60.02%, respectively. based on the benchmark values obtained from each of the supporting instruments used in the 450 caliber x rocket igniter system, the results of the priority scale are obtained for developing the rocket igniter system to avoid from malfunctions. the results show that the instruments that need to be studied more are the squib, pyrotechnics, emergency button, ground system and wiring system. list of requirement l ev el o f in te re st design characteristics p ow er s u pp ly c ab le g ro un d c as in g sq ui b p yr ot ec h ni c e m er ge nc y b u tt on 2 volt and 1 ampere 4 9 9 9 1 9 1 9 circuit breaker 5 9 9 9 1 3 3 9 low resistance 3 3 9 9 1 3 3 9 melting points and even distribution of burning 5 1 1 1 9 3 9 3 long storage time 4 3 1 1 3 9 9 3 high heating value 4 1 1 1 1 9 9 3 high sensitivity value 4 1 9 9 1 9 9 3 final score (level of importance x design characteristic) 115 157 157 77 183 181 159 benchmark performance (%) 44.06 60.15 60.02 29.05 70.11 69.35 60.9 priority scale 6 4 5 7 1 2 3 dss vol. 3, 2022, pp.130-133 133 4. conclusions analysis of the importance priority to be studied on the igniter system of 450 caliber x rocket has been conducted, the results of the identification of the need for an igniter system for the x rocket were carried out with a list of requirements, to ensure that no required requirements were missed. the results obtained in the form of user requirements data which include squib with a final score of 183 with a benchmark performance value (bp) of 70.11%, pyrotechnics with a final score of 181 and a bp value of 69.35%, emergency button with a final score of 159 and a bp value of 60.9%, cables with a final score of 157 with a bp value of 60.15%, ground with a final score of 157 with a bp value of 60.02%, a power supply with a final score of 115 with a bp value of 44.06%, and casing with a final score of 77 with a bp value of 29.05%. the value obtained becomes a reference as an effort in conducting research and development, to avoid the igniter from malfunctions when the system is running. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] bppi. k. " indonesian defense white paper", ministry of defense of the republic of indonesia, 2015. [2] ministry of defense of the republic of indonesia, " regulation of the minister of defense, alignment of minimum essential force main components ", 19 (650), 4-35, 2017. [3] a. irfansyah, "conceptual design of the rx-1220 rocket-based air defense missile aerodynamics system", 2020. [4] r. h. triharjanto, a. riyadl, l. marian, i. e. putro, "initial design and development strategy for lapan cruise missiles", lapan journal, 2008. [5] g. samosir, "calculation and design of igniter based on rocket propulsion calculation (case study of rx-320 rocket)", journal of aerospace technology, vol. 9 no. 2, december, 2011. [6] b. r. briody, "electrical current requirements of model rocket igniters", 2000. [7] e. lestariana, "squib as electric ignition wick", journal of aerospace, 9(2), 46-50. 2008. [8] l. cohen, "quality function deployment: how to make qfd work for you", addison-wesley publishing company, boston, 1995. microsoft word 52-58_186 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.52-58 https://doi.org/10.37868/dss.v4.id186 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 52 a 41% bandwidth microstrip patch antenna mehmet yusuf imeci1, s. taha imeci2, ramazan daşbaşı3 1 international university of sarajevo, department of electrical engineering, bosnia and herzegovina 2 fatih sultan mehmet vakıf university, department of electrical and electronics engineering, fatih-i̇stanbul, türkiye 3 yildiz technical university, electronics and communication engineering, türkiye *corresponding author e-mail: mehmedyusufimeci@gmail.com received: jul. 14, 2022 revised: feb. 20, 2023 accepted: feb. 27, 2023 online: mar. 2, 2023 abstract this work contains a wideband ds (defected-ground-structure) microstrip patch antenna. initially, the intention of this work was based on realizing a sub-6 ghz 5g microstrip patch antenna, but through many experimentations, we inadvertently stumbled upon a different kind of microstrip patch antenna, namely, an antenna with a substantially wide band. the numeric values of the variables/parameters of this compact, wide-band, microstrip patch antenna, which has a proudly high fabrication tolerance, are as follows: 𝑆 = −10.09 𝑑𝐵, 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 = 8.7 𝐺𝐻𝑧, 𝜀 = 2.67 𝑑𝐵, 𝜀 = −2.3 𝑑𝐵. the bandwidth reaches approximately 6.6 ghz to 10.2 ghz, hence giving this particular design’s bandwidth a proud 41% value. the inspiration for this work came from [11], which posed two symmetrical antennas opposite from one another, whereas this work has produced a singular antenna, with a more circular center, and with other many modified traits. © the author 2023. published by arda. keywords: dgs, microstrip, patch, antenna, wideband, sub-6 ghz, 5g 1. introduction printed patch radiators didn’t really shine in the world of technology until the 1970s when the wireless data transfer methods in communication systems practically skyrocketed. even though these types of antennas are small and fairly cheaply produced, they still hold the capability of being integrated with rf circuits [1]. for the past about 10 years or so, dielectric resonators (dr) have quite increasing popularity owing to their practicality [2]. as you, the typical reader of this type of work would probably know, 5g stands for fifthgeneration mobile network. in a broad sense, explaining it could simply boil down to how its main purpose, is to connect everything together, as far as in the realm of communication systems. [3]. millimeter-wave (mmwave) bands coupled with 5g technology, allow data to be transferred in substantially greater amounts [4]. technologies such as say, today’s cell phones, especially ones that operate below 3 ghz, are used quite a lot in the sub-6 ghz range [5]. dual-band antennas are a lot of times constructed by choosing different parts in different band values, and adding them to construct a new part [6]. sub-6 ghz technology with respect to mm-waves not only surpasses physical range, thus covering greater distances, it also poses as a cheaper alternative with a wider bandwidth, which brings a high amount of data transferring capability [7]. high-speed and low-latency data transfer has become increasingly important as wireless systems got increasingly sophisticated in a relatively short span of time [8]. studies indicate the details on how the antenna’s properties conform to various stub parameters [9]. all in all, microstrip patch antennas are a great companion to be coupled with 5g applications [10]. lots of smartphones in these past years that are to be integrated with 5g, have been posed with wideband antennas that are not only as high as 6 ghz but are also as less efficient as 50% [11]. the absolute explosion of the internet of things (iot) and various other wireless technologies in our current era of technological developments, has made it somewhat crucial for newer and better dss vol. 4, 2023, pp.52-58 53 breakthroughs and technologies to emerge for better inner adaptability, and 5g is one such example. [12]. there isn’t even a need to state the obvious of the absolutely crucial role of the internet in data transmission in high quantities [13]. sub-6 ghz technology surely helps in this high quantity and high-speed data transfer [14]. omni-directional antennas aren’t particularly the highest-range antennas [15]. a patch antenna is basically a radio antenna that you can easily just mount to a surface. [16]. the microstrip patch antenna finds itself a role in all ranges of mobile communication systems [17]. (5g) technology is definitely on the rise where communication systems are concerned, and this explosive widening of its use happens to be occurring in many nations worldwide. [18]. to fully realize and reap the benefits of 5g technology, small and highly efficient antennas are a must [19]. 5g has substantially reduced latency and many many other benefits with respect to 4g. therefore, 5g is expected to rule the domain it’s present in, for the foreseeable future in our current era where technological developments are at an all-time rise [20]. 2. research method all research for this publication has been made possible with use of sonnet software, which is a simulation tool that is widely popular in microwave circuit analyses. as you can see from the following three figures, (figures 1-3), our microstrip patch antenna design consists mainly of rectangular shapes, with the only exception of the center, which is basically a circle. the metal parts of the design are obviously much smaller than the whole design, as the dimensions are about 1.5 to 4.5 centimeters, while the whole box size is about 24 to 8.5 centimeters. the thickness of the whole design, as it may appear from the 3d view below, looks quite massive, but we remind you that that’s just a close-up zoomed-in view of the design, and in reality, with all the layers combined, the whole design is only as thick as about 3 centimeters. as it appears from the simulation results from sonnet software regarding our design (figure 4), our band range starts from about 6.5 ghz, and goes all the way up to a little over 10.2 ghz, and thus, corresponds to a bandwidth value of 41%. it may also be apparent that the lowest point of 𝑆 appears to be just a little below -25 db. 3. results and discussion the dimensions and shape of this antenna design is shown in figure 1, figure 2, and figure 3. figure 1. the top view with dimensions in mm (box not included) figure 2. the 3d view (main part) figure 3. 3d view (complete) dss vol. 4, 2023, pp.52-58 54 patch antenna main design results of the s-parameters are shown graphically in figure 4. figure 4. the s-parameters graph for the main design one can observe below in (table 1) that when we changed the dielectric constant values starting from 4.3, and going all the way up to 4.5, our frequency and gain results practically didn’t change. the closest result to the original design came when the dielectric constant value was 4.5 (4.4 was the original value). table 1. changing the dielectric constants (main design values in bold) dielectric constant (εr) magnitude (db) frequency (ghz) s11 εθ εφ 4.3 -13.01 2.38 -2.55 8.62 4.35 -13.45 2.35 -2.52 8.58 4.4 -9.79 2.67 -2.3 8.7 4.45 -13.59 2.38 -2.51 8.54 4.5 -12.06 2.51 -2.52 8.64 as it can be seen in the following (table 2) that when we changed the dielectric thicknesses starting from 1.5 mm, and going all the way up to 1.6mm, our frequency and gain results practically didn’t change. the closest result to the original design came when the dielectric thickness value was 1.57 mm (1.55 mm was the original value). table 2. changing the dielectric thicknesses (main design values in bold) dielectric thickness magnitude (db) frequency (ghz) s11 εθ εφ 1.5 -13.56 2.45 -2.41 8.62 1.53 -12.96 2.47 -2.5 8.62 1.55 -9.79 2.67 -2.3 8.7 1.57 -11.64 2.47 -2.56 8.68 1.6 -11.37 2.44 -2.63 8.66 bw = 41% db[s11] patch antenna main design dss vol. 4, 2023, pp.52-58 55 when we consider the following results (table 3), when we changed the length of the center in the y-axis starting from 14.5 mm, and going all the way up to 15.5 mm, our frequency and gain results again practically didn’t change. the closest result to the original design came when the length of the center in the y-axis was 14.75 mm (15.07 mm was the original value). table 3. changing the length of the center in the y-axis (main design values in bold) the length of the center in the y-axis magnitude (db) frequency (ghz) s11 εθ εφ 14.5 -11.57 2.66 -2.3 8.54 14.75 -10.38 2.72 -2.34 8.64 15.07 -9.79 2.67 -2.3 8.7 15.25 -11.43 2.63 -2.19 8.54 15.5 -11.9 2.57 -2.04 8.5 as it’s apparent from the table below (table 4), when we changed the length of the center in the x-axis starting from 15 mm, and going all the way up to 17 mm, our frequency and gain results once again practically didn’t change. the closest result to the original design came when the length of the center in the x-axis was 15 mm (16 mm was the original value). table 4. changing the length of the center in the x-axis (main design values in bold) the length of the center in the x-axis magnitude (db) frequency (ghz) s11 εθ εφ 15 -12.1 2.5 -2.53 8.66 15.5 -12.11 2.57 -2.42 8.58 16 -9.79 2.67 -2.3 8.7 16.5 -10.91 2.65 -1.9 8.48 17 -10.29 2.58 -1.4 8.38 please refer to the below results (table 5), to see that when we changed the length of the ground in the x-axis starting from 29 mm, and going all the way up to 31 mm, our frequency and gain results once again practically didn’t change, but at 29.5 mm, we had a weird spike in frequency (from 8.68 to 8.74), but the closest result to the original design came when the length of the ground in the x-axis was 30.5 mm and at 31 mm. at 30.5 and 31 mm, the frequencies were the same and 8.68 ghz, which is the same exact frequency with the original design (30 mm was the original value). table 5. changing the length of the ground in the x-axis (main design values in bold) the length of the ground in the x-axis magnitude (db) frequency (ghz) s11 εθ εφ 29 -11.63 2.47 -2.4 8.62 29.5 -11.22 2.45 -2.41 8.74 30 -10.09 2.67 -2.28 8.68 30.5 -12.41 2.48 -2.61 8.68 31 -14.89 2.45 -2.7 8.68 we can refer to the below figure (figure 5) to view the current distribution. the darkest blue, illustrating zero current being distributed, while the darkest red oppositely illustrating the highest amount of current being distributed, note that the colors cause the current distribution to be clearly and vividly represented. this current distribution is specifically illustrating the distribution at 8.7 ghz, which is the original frequency of the design. dss vol. 4, 2023, pp.52-58 56 figure 5. the current distribution note that in the following two figures (figures 6-7), the gain results of the 8.7 ghz main design are presented. and the main results are 𝜀 = 2.67 𝑑𝐵 (figure 6), and 𝜀 = −2.3 𝑑𝐵 (figure 7). figure 6. the phase angles graph (e-theta) figure 7. the phase angles graph (e-phi) dss vol. 4, 2023, pp.52-58 57 4. conclusions as it may be obvious from previous reading of this current work, our antenna design with the given characteristics (𝑆 = −10.09 𝑑𝐵, 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 = 8.7 𝐺𝐻𝑧, 𝜀 = 2.67 𝑑𝐵, 𝜀 = −2.3 𝑑𝐵), poses a unique and valuable presence in communication systems, at the current era the world resides in. even though the initial intentions of this work were to realize a completely different type of antenna with a fairly dissimilar category (a sub-6 ghz 5g microstrip patch antenna), the beauty of experimentation and the surprises it may offer (like in this case), sometimes delivers a completely different but no less important type of separate technology. parametric studies, where the fabrication tolerances are obviously present, also supports the tangible value and practicality of this 41% bandwidth design of a miniature beast, that despite its puny size, has a pretty far reach (high frequency range). declaration of competing interest the authors declare that they haven’t any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] a. kapoor, r. mishra, and p. kumar, “wideband miniaturized patch radiator for sub-6 ghz 5g devices,” heliyon, vol. 7, no. 9, p. e07931, 2021. [2] j. iqbal, u. illahi, m. n. m. yasin, m. a. albreem, and m. f. akbar, “bandwidth enhancement by using parasitic patch on dielectric resonator antenna for sub-6 ghz 5g nr bands application,” alex. eng. j., vol. 61, no. 6, pp. 5021–5032, 2022. [3] a. al-gburi, “wideband microstrip patch antenna for sub 6 ghz and 5g applications,” prz. elektrotech., vol. 1, no. 11, pp. 28–31, 2021. [4] d. n. gençoğlan and ş. çolak, “investigation of origami inspired sub-6 ghz accordion monopole antenna for 5g applications,” sak. univ. j. sci., vol. 25, no. 4, pp. 974–983, 2021. [5] m. yerlı̇kaya, s. s. gültekı̇n, and d. uzer, “a novel design of a compact wideband patch antenna for sub-6 ghz fifth-generation mobile systems,” international advanced researches and engineering journal, vol. 4, no. 2, pp. 129–133, 2020. 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[15] m. farasat, d. n. thalakotuna, z. hu, and y. yang, “a review on 5g sub-6 ghz base station antenna design challenges,” electronics (basel), vol. 10, no. 16, p. 2000, 2021. [16] t. aathmanesan, “novel slotted hexagonal patch antenna for sub-6 ghz 5g wireless applications.”. [17] a. kapoor, r. mishra, and p. kumar, “compact wideband-printed antenna for sub-6 ghz fifth-generation applications,” int. j. smart sens. intell. syst., vol. 13, no. 1, pp. 1–10, 2020. [18] p. dwivedi and d. sen, “micro-strip antenna design for 5g sub 6 ghz and wi-fi applications,” int. j. sci. res. (raipur). [19] b. tütüncü and m. kösem, “substrate analysis on the design of wide-band antenna for sub-6 ghz 5g communication,” wirel. pers. commun., pp. 1–13, 2022. [20] darwin and sampath, “sub-6 ghz band massive mimo antenna system for variable deployment scenarios in 5g base stations,” research square, 2021. microsoft word 101-105_208 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.101-105 https://doi.org/10.37868/dss.v3.id208 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 101 concept of military asset management system (mams) in indonesian national armed forces zairullah azhar1*, wahyu sri setiani2, khevinadya ramadhani runtu3, y. h. yogaswara4 1,2,3,4faculty of defense technology, weaponry technology department, indonesian defense university, indonesia *corresponding author e-mail: zairullah.azhar@tp.idu.ac.id1 received: nov. 11, 2022 revised: dec. 1, 2022 accepted: dec. 1, 2022 online: dec. 5, 2022 abstract the internet of things (iot) is a very fast-growing technology and has a huge impact on our daily life, including military performance. in the military, iot known as the internet of military things (iomt) or internet of battlefield things (iobt) has the function create network communication to increase readiness in the military and can apply to all aspects of military asset management and uses the interconnection, real-time, and intelligent innovation of the iot technology to build a military asset management system. the research purpose is to analyze the military asset management system (mams) in indonesian national armed forces. the research applies a qualitative research methodology. the literature review method and the interviews were used to obtain data and analyze to describe or explain the phenomenon of problems with the maintenance, repair, and overhaul (mro) and military asset management system (mams) in supporting the operation of the alutsista indonesian national armed forces. the research result shows that the integration of asset management in the indonesian national armed forces is still not centralized, which it means needs more time to collect material asset data and of course, will impact the readiness of the military. in this case, complex aerial mission simulation (cams) can be a reference for indonesian national armed forces to develop a military asset management system (mams). © the author 2022. published by arda. keywords: military asset management systems (mams), internet of things (iot), complex aerial mission simulation (cams) 1. introduction indonesia as a country with a strategic location is an attraction for other countries with various interests. the influence of the strategic environment, both nationally, regionally, and globally, makes indonesia must always alert to threats that may occur. this situation of course must be a concern, especially in the defense sector. uncertainty of threats that may occur, makes the defense sector must always be ready to deal with them. the readiness and effectiveness of the armed forces are highly dependent on the state of its equipment in terms of availability and reliability [1] one thing that particularly challenging in the defense environment is readiness management because it’s related to the complexity of the weapons systems and large mixed military fleets. efficient fleet maintenance management requires the ability to manage the flow of information between forces to reach readiness. in case to prepare the readiness of the military force, we can take advantage of the use of the internet of things (iot). iot is a concept where an object can the ability in terms of communicating via a network, such as a process of transferring data without any communication process carried out between humans (humans to dss vol. 3, 2022, pp.101-105 102 humans) or between humans to system devices such as computers or a controller. although this concept was less popular until 1999, iot has been in development for decades. the internet of things or often called iot is an idea where all objects in the real world can communicate with each other as part of an integrated system using the internet network. iot devices consist of sensors as data collection media, internet connections as communication media, and servers as information collectors received by sensors and for analysis. internet of things technology builds the work process of a system that can be wider, the range of reach is also wider, and the data processing and data analysis of a system is also getting better. this iot technology supports the work of the system as a whole including components or elements in terms of facilitating the process of data information flow. in the military, iot is known as the internet of military things (iomt) or the internet of battlefield things (iobt). the purpose of iomt and iobt is to create network communication. internet of military things (iomt) dan internet of battlefield things (iobt) technology is applied to all aspects of military asset management and uses the interconnection, real-time, and intelligent innovation of the iot technology to build a military asset management system. according to the pas-551 [2] standard on asset management from the british standards institute, asset management is defined as: “systematic and coordinated activities and practices through which an organization optimally and sustainably manages its assets and asset systems, their associated performance, risks and expenditures over their life cycles to achieve its organizational strategic plan”. based on this definition, of course in the military, asset management has an important role to develop a list of all the organization’s assets and verify this list with what is in the field. various countries have utilized the internet of military things (iomt) and the internet of battlefield things (iobt) in asset management systems. one of them is the french military through the dassault system developed complex aerial mission simulation (cams)[3]. cams is a dassault-made tool developed for industrial purposes to technical optimization for industrial roadmap choices, operational requirement analysis for export contracts, and product robust and intuitive feedback on studies. cams is a technical and operational simulation tool, that focuses on the mission level and deals with the main mission phases. it's designed to study the global efficiency of an aerial combat system, within credible operational context survivability, lethality, and effectiveness. cams will influence the decision-making related to logistics and deployment, also cams is used to find out what the best weapons will choose for shooting enemy fighter aircraft. the benefit of cams definitely would increase the readiness of the defense force[4]. cams can calculate both the readiness of the material used in war and the strategy and use of weapons that have been calculated and simulated in detail. cams can also serve as military asset management for the french army. cams can also serve as military asset management for the french army. based on current conditions in indonesia. the use of iot technology in the military field is still not felt enough. especially on the asset management system. with the use of technology that has been used in various countries. indonesia can take advantage of iot technology in an asset management system for defense equipment. in this research, references in developing a military asset management system (mams) only focus on cams that have been developed by dassault systems. this research was conducted to describe the conceptual design related to the asset management scheme within the indonesian national armed forces and provide an overview of how the military asset management system is implemented in the indonesian national armed forces. 2. research method the research was conducted by applying a qualitative research methodology. qualitative research refers to analysis that produces findings obtained through data collected by various means, including interviews, observations, documents or archives, and tests [5]. the literature review method and the interviews were used to obtain data and analyze to describe or explain the phenomenon of problems with the maintenance, repair, and overhaul (mro) and military asset management system (mams) in supporting the operation of the alutsista indonesian national armed forces. interviews were applied to obtain information directly. in this study, the informants interviewed by the researchers are the director of dgt of dassault aviation. the informant will be asked for their opinion regarding the complex aerial mission simulation (cams). furthermore, other informants will be asked for their opinion regarding the maintenance, repair, and overhaul (mro) and military asset management dss vol. 3, 2022, pp.101-105 103 system (mams) in the indonesian national armed forces, representative of the indonesian army, the indonesian navy, and the indonesian air force. meanwhile, literature studies were applied referring to the maintenance, repair, and overhaul (mro) system in the indonesian national armed forces. literature studies are carried out by reviewing previous research journals and then reviewing and discussing them. the results and discussion were obtained by collecting various data from references to the results of interviews and relevant journal reviews. furthermore, the concept implementation of the military asset management system (mams) was made, and then the mams can help the indonesian national armed force in carrying out its operational duties. 3. results and discussion military asset management system (mams) is needed to calculate and analyses what military strength is if one day there is a war. the command operation can find out how many materials are ready to use and not suitable for use in real time. military asset management systems (mams) are directly related to inventory management, mro management, and predictive maintenance analysis. the diagram of military asset management can be seen below in figure 1. figure 1. diagram military asset management in the current condition of the indonesian national armed forces, asset management is still not centralized, so it takes time to collect material asset data. this can hinder the analysis of military strength. military asset management systems (mams) are needed that are integrated between units and can be monitored in real time. not only material assets that are ready to be used, but can monitor assets that are under maintenance. the maintenance system is carried out in each force. the material maintenance system in the indonesian army is arranged in stages and tiers based on the level of material maintenance and the level of the implementing unit for the material maintenance task. material maintenance as maintenance and prevention or organic maintenance is carried out by the unit using the material. furthermore, maintenance at the field level is carried out by the maintenance unit at the military regiment command (korem) level, namely the field workshop (benglap). maintenance at the regional level is the responsibility of the regional workshop (bengrah) which is the maintenance unit at the kodam level. the highest level of maintenance, namely maintenance at the central level, is carried out by the central workshop and equipment (bengpuspal) [6]. in the navy, maintenance is carried out in stages. where is the organic level maintenance (harnik) which is supported by the ability of the crew, materials, and equipment on board. maintenance of the medium level (harmen) of this stage of difficulty requires the ability of experts, materials, and equipment on board so that it dss vol. 3, 2022, pp.101-105 104 must be supported by the warship maintenance and repair facility (fasharkan). maintenance at the depot level (hardepo) with difficulty levels increasingly requires the assistance of foreign workers, spare parts, and materials that are not supported by the warship maintenance and repair facility (fasharkan) so it needs to be carried out by the shipyard and in increasing operational capabilities in the context of extending the service life based on the results of the study. enhanced capabilities include modernization (when the ship is in the program's life cycle period) and life of use (when the ship has exceeded its life cycle). this maintenance phase is carried out by the warship maintenance and repair facility (fasharkan), national shipyard (galkapnas), and maritime service industry (injasmar) [7]. the material maintenance system in the indonesian air force is carried out by the air force material maintenance command (koharmatau). the koharmatau has the task of preparing and carrying out the maintenance of the indonesian air force alutsista to support operations and training activities. in carrying out its duties and functions, the koharmatau has maintenance depots as implementing units, namely the maintenance depot (depohar) 10, depohar 20, depohar 30, depohar 40, depohar 50, depohar 60, and depohar 70. depohar functions as the implementing unit for the koharmatau or is directly domiciled under the commander of the koharmatau. each of these depohars is tasked with carrying out corrective and restorative maintenance, material production, and supplying the level of supplies for weapons, guided missiles, ammunition/explosives as well as carrying out the demolition of weapons and ammunition/explosives. in carrying out its duties, maintenance depot (depohar) is assisted by several maintenance units including the maintenance unit [8]. current conditions, material data that is in a condition of maintenance and care is still in written form. not yet in the form of an integrated system with each other. to improve this, the implementation of the military asset management system (mams) is very important. data related to material maintenance and care is input by the maintenance and maintenance implementing unit, both at the organic, middle, and upper levels. the module diagram concept of the military asset management system can be seen below in figure 2. figure 2. concept military asset management system data retrieval is carried out in each force where maintenance data are taken from organic, intermediate, and depot units. it is centralized in the maintenance command database. as for asset management data, it is taken from the operation unit and centralized in the main command database. data that has been centralized on the maintenance and operation command is centralized back to the headquarters database of each force. furthermore, it is centralized in the server of the military asset management system. dss vol. 3, 2022, pp.101-105 105 in the centralized database and management system, there is some information such as mro management, asset database, inventory management, and predictive maintenance analysis. the input data is in the form of field reports and data logging so that the data can be monitored. the military asset management server is located at the tni headquarters and the data is protected because the data contains strategic data, so we need a good data security system so as not to get hacked. data that has been centralized in the military asset management system can be directly monitored in realtime so that if a strength analysis is needed at any time, it can be done quickly and accurately because the data used is real-time data. so, the military asset management system (mams), can help the indonesian national armed forces in carrying out its operational duties. 4. conclusions the integration of asset management in the indonesian national armed forces is still not centralized, which means needs more time to collect material asset data and of course, will impact the readiness of the military. military asset management system (mams) is an integrated system both in the indonesian navy, indonesian army, and indonesian air force which contains data on assets in the form of weapons, tanks, planes, ships, and other platforms. also, military asset management system contains the conditions for the platform and this is only used internally to prepare strength readiness. the equipment asset management system under the iot technology has the advantages of a large amount of information, comprehensive interoperability, and high data processing efficiency. the real-time query of data, real-time reports, and performance evaluation automatically generate a comprehensive and dynamic monitoring system for the military. in this case, complex aerial mission simulation (cams) can be a reference for indonesian national armed forces to develop a military asset management system (mams). acknowledgments the author would like to thank the committee of the overseas study program 2022 from the defense technology faculty of the republic of indonesia defense for their facilitation in team formation, data search, and encouragement to publish this paper. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. references [1] p. perera, s. nanayakkara, and a. perera, “application of proper asset management methodology and technology in defence sector of sri lanka”, international conference on advances in computer science, electronics and communication technologies, pp. 33–41, 2014. [2] british standards institute, british standards institution’s publicly available specification for the optimised management of physical assets, the institution of asset management, united kingdom, 2011. [3] joel rode, “tactical preparation mission system,” dassault system, france, 2022. [4] faculty of defense technology, “results of overseas study program,” republic of indonesian defense university, jakarta, 2022. [5] anselm strauss, juliet corbin, dasar dasar penelitian kualitatif, pustaka pelajar, yogyakarta, 2003. [6] u. santoso, r. widodo putro, and s. munthe, “the system strategy of material maintenance directorate equipment army (ditpalad) in the modernization defense equipment of indonesian national army (tni ad),”,” jurnal strategi pertahanan darat, vol. 6, no. 1, pp. 91–110, 2020. [7] g. ketut, h. desember, i. nengah putra a, and d. dar, “the strategy of maintenance, repair and overhaul (mro) for the indonesian navy ships to support the readiness of sea operations in fasharkan lantamal v surabaya,” jurnal teknologi daya gerak, vol. 3, no. 2, pp. 96–114, 2020. [8] m. kemalsyah, d. a. dadang, and p. strategi pertahanan udara fakultas strategi pertahanan, “the influence of soldiers professionalism and maintenance facilities on operational readiness of fighter missile in the 65 maintenance unit 60 maintenance depot madiun”, jurnal strategi pertahanan udara, vol. 6, no. 1, pp. 1–20, 2020. microsoft word 74-82_203 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.74-82 https://doi.org/10.37868/dss.v3.id203 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 74 the concept of stealth unmanned combat aerial vehicle (ucav) to support air defense systems opa mustopa1*, romie oktovianus bura2 1,2 faculty of defense technology, indonesia defense university, indonesia *corresponding author e-mail: opa.mustopa@tp.idu.ac.id received: oct. 27, 2022 revised: nov. 13, 2022 accepted: nov. 14, 2022 online: nov. 17, 2022 abstract one platform that is currently highly developed as an air defense technology is the unmanned combat aerial vehicle (ucav) which is a uav system equipped with a weapon system or has combat capabilities. in this study, the ucav concept was developed with the aim of having a stealth or low observability aspect by being shown to have a low radar cross-section (rcs) value. in this paper, the ucav model developed is a generic ucav configuration developed by the nato sto/avt-161 task group, namely saccon ucav. the saccon ucav is also goal-oriented typical of low observability with a combination of high agility and high angle of attack (aoa) capabilities. the results of the saccon ucav design were then analyzed by the rcs value using the sbr method using the ansys hfss software. the results of the rcs calculation show that the saccon ucav model has a low rcs value and the rcs value can be reduced again by shaping the ucav configuration. © the author 2022. published by arda. keywords: unmanned combat aerial vehicle (ucav), stealth technology, radar cross section (rcs), saccon ucav 1. introduction talking about a country's defense system, one of the most important aspects to study is the air defense system. due to the development of the times, defense technology, especially aircraft technology, is also developing. now every country in the world is competing to create a concept of fighter aircraft as a means of national defense in airspace. and one of the air defense technologies that is currently highly developed is the unmanned aerial vehicle (uav). the uav system is an unmanned aircraft flight system that is not manned by humans, which is controlled remotely, either manually or automatically, which consists of unmanned aircraft, payloads, human resources, control systems, data networks, and supporting elements [2]. utilization of the uav system basically can be an appropriate alternative to overcome existing problems, as well as a response to the influence of rapid technological advances, and in line with the implementation of revolution in military affairs (rma), which is aimed at achieving network centric operation or network centricwarfare [7]. the ability of the uav system to carry out surveillance of the national territory by air with its characteristics and advantages, including in terms of flexibility and range, minimized operational risks, and the ability to fly for a relatively long period of time, is a significant consideration for the unmanned aerial vehicle to be able to empowered as a reliable defense equipment to support national defense [8]. the development of the uav system is currently very widely used and is used for various missions such as intelligence, surveillance, reconnaissance and even including uav for attack missions or commonly called unmanned combat aerial vehicle (ucav) [4]. in carrying out these various missions, the uav/ucav also dss vol. 3, 2022, pp.74-82 75 requires a supporting technology, one of which is stealth technology .technology stealth aims to avoid detection by enemy defense radars, so that the uav/ucav can more freely carry out its mission [9]. 1.1. concept of stealth technology the emergence of stealth is caused by the emergence of major changes in the scope of warfare that bring the application of technological inventions combined with fundamental changes in doctrine, operations and concepts of military organization, which are fundamentally related to the character and way of conducting military operations. this change is generally known as revolution in military affairs (rma) [6]. therefore, major countries are trying to develop weapons as a product of their defense industry by prioritizing the application of advanced technology. in general, the purpose of using this technology is to launch attacks using aircraft in enemy areas without being detected by the air defense radar [1]. to meet the stealth of the aircraft, there are three things that can be minimized, namely: 1. visual aspects, such as eliminating smoke trails, repainting or repainting the aircraft to resemble environment in which the mission is carried out. 2. infrared aspect which reduces the use of after burner. 3. radar aspect, namely reducing the radar cross section (rcs) of the aircraft. low surveillance is felt to be able to increase the probability of a fighter aircraft's success in carrying out its mission because it is able to provide an element of surprise in the opponent's area. in addition, with the existence of low surveillance combat aircraft, it is hoped that the aircraft will be able to have a better life cycle than combat aircraft that have a higher rcs [3]. radar cross section (rcs) is the ability of an object to reflect the radar signal back to the transmitter source. the smaller the rcs value of an object, the more difficult it is for the object to be detected by enemy radar. the advantages of reducing rcs are as follows: 1. reduction of the detection distance from the target or aircraft. 2. a reduction in the search area or search volume of enemy radar will take longer to scan than for the same amount of space . 3. the enemy defense radar will not be able to detect what objects are approaching [5]. therefore, stealth in aircraft is currently being developed with various methods, one of which is by modifying the shape of the aircraft (shaping) and with material technology that can absorb and deflect radar electromagnetic waves or commonly known as the radar absorbing material (ram) method [10]. the following is a graphic illustration of the difference in rcs values on conventional aircraft with aircraft that have stealth. figure 1. graph of comparison of rcs values between conventional aircraft (20 db) and stealth (-10 db) [1]. dss vol. 3, 2022, pp.74-82 76 it can be seen in the image above that by modifying the shape of the aircraft using stealth technology, the rcs value is much smaller than ordinary conventional aircraft, meaning that the aircraft with stealth technology is able to provide superiority to the effect of enemy radar monitoring range so that it is suitable for use on uav for military missions or in this case for surveillance missions, reconnaissance and even attacks in the new state capital area. 1.2. radar cross section (rcs) radar cross section is the ability of a target to reflect back the radar signal towards the source from the radar transmitter. rcs has units of square meters because rcs shows signature of a target, especially fighter aircraft, because it can be said that rcs also shows the projected area of a metal sphere that will emit a certain amount power towards a target [3, 11]. in the usual rcs analysis, there are two types of cases as shown in figure 2, namely the monostatic where the radar transmitter-receiver is located in one place, or the bistatic where the radar transmitter and receiver are separated at different locations. figure 2. reference rcs concept [11] 2. research method in predicting the rcs value, there are several techniques or methods which are broadly divided into two, namely the exact method and numerical approximation. in this research, the method used is numerical approximate with the help of ansys hfss software. shooting and bouncing ray (sbr) method is an approximation method to calculate the rcs value with high frequency, so that predicting the rcs value on large objects will be more effective because great accuracy can be achieved in high frequency analysis [13, 14]. this sbr method is the latest method in analyzing rcs values based on ray tracing and combines geometric optics (go) and physical optics (po) approaches. the advantage of the sbr method is that it can consider several reflection effects and shadow effects. use of the sbr method requires a scattering analysis (sa) process which is carried out in 3 stages. dss vol. 3, 2022, pp.74-82 77 figure 3. process of sbr method [12] for analysis, the sbr method still has a weakness because it has not considered the diffraction field at the edges. therefore, ansys hfss v193 software is used. in hfss, sbr is available with advanced diffraction and wave creep physics for increased accuracy. the following is the flow of analysis in predicting the rcs value with the sbr method in the ansys hfss software. figure 4. flowchart of rcs analysis with the sbr method in the ansys hfss software. 3. results and discussion 3.1 unmanned combat aerial vehicle (ucav) design the unmanned combat aerial vehicle (ucav) model used is a generic ucav configuration developed by the nato sto/avt-161 task group, namely saccon ucav. the main reason for choosing this ucav platform is because the geometry of the saccon ucav platform has been designed with stealth requirements which lead the ucav design to the flying wing concept. the basic lambda-shaped geometry of the saccon ucav configuration is also oriented towards the typical goal of low observability with a combination of high agility and high angle of attack (aoa) capabilities, so that in addition to considering low capabilities detected by enemy defense radars, this saccon ucav model was also developed as a realistic ucav concept. the mission parameters and boundary conditions applied to the saccon ucav design are given in table 1 and figure 5 below. table 1. mission parameters and boundary conditions yes dss vol. 3, 2022, pp.74-82 78 figure 5. design mission of saccon ucav the total payload mass for the ucav is 2000 kg. due to signature requirements, the internal storage must be in one or two payload space. a design range of 3000 km without aerial refueling is considered sufficient as an additional spare time of about 45. with this assumption, an operational radius of 1500 km can be achieved. cruising flights to the target area were carried out at an altitude of 11 km with a rate of mach 0.8. in the target area, the ucav must descend to an altitude of 300 m while maintaining a mach figure of 0.8. during the last kilometers it can even descend to 250m and accelerate to mach 0.9 but due to its fixed outer shape, this is only an optional requirement. to maintain good maneuverability for this ucav flying wing without making it laterally unstable, a stability margin of 2–8% was chosen. furthermore, the typical mission of saccon ucav is given in figure 6 below. figure 6. typical mission of saccon ucav the following is an explanation of the typical saccon ucav mission as follows 1) take-off the aircraft will operate outside the airfield in several friendly areas. the length and distance of the runway to some threshold heights will be limited. this is very important for aircraft carrier operations. 2) climb the aircraft will rise to its cruising altitude, precisely at the edge of the stratosphere (~11,000 m). a high climb rate and low fuel requirement would be desirable. 3) cruise the plane will sail to a roaming location. with speeds just below the mach drag increase rate then long distances and fast sailings are desirable. 4) loiter the aircraft will roam, perhaps at a lower altitude, in an area that can use sensors and possibly use weapons. here long endurance is very important. 5) dash the aircraft will fly towards its target as quickly as possible to deploy weapons and/or gather intelligence. maximum speed here is very important. 6) approach during approach, the aircraft will lose altitude to land. 7) landing the aircraft must be able to slow itself down to landing speed. after landing, he must stop before the end of the runway. dss vol. 3, 2022, pp.74-82 79 furthermore, to design the saccon ucav platform, it is necessary to determine the design variables and the geometry of the aircraft to be parameterized first. figure 7 below is given the design variables with some assumptions or limitations. figure 7. saccon ucav geometry parameterization then with the help of catia software, a saccon ucav platform design was made based on the variables and parameters that have been previously determined in figure 7 so that the saccon ucav design was obtained as follows figure 8. design of saccon ucav the coordinate system in saccon ucav are given in figure 9 below. figure 9. coordinate system of saccon ucav dss vol. 3, 2022, pp.74-82 80 3.2 radar cross section (rcs) analysis of saccon ucav in conducting the radar cross section (rcs) analysis to calculate the value approach, it is carried out numerically with the help of the ansys hfss (high frequency structure simulator) 2019 r3 software. to perform the radar cross section (rcs) simulation, the assumption used is that the material used is in the form of perfect electric conductor (pec) which is an ideal material that can restore electromagnetic wave energy perfectly so that it is suitable for simulation of radar cross section (rcs) calculations. then the frequency used is 10 ghz, which includes high-frequency x-band radar with a frequency range of 8-12 ghz. this x-band radar is a type of radar commonly used in the military world to detect military aircraft, including aircraft with stealth technology that are still within the range of this radar. then the threat area used is 90° on the elevation plane and 0° to 360° on the azimuth plane. after these assumptions are inputted, then a setup simulation is carried out using the sbr+ method approach with the type of radar receiver used is a monostatic radar. the following are pictures of the simulation results of the radar cross section (rcs) on the ucav saccon model. figure 10. simulation of rcs linear plot figure 11. 3d rcs plots over the entire surface of the ucav geometry dss vol. 3, 2022, pp.74-82 81 then from the simulation results above, the calculation of the rcs value can be generated as a result of entering the input in the rcs simulation in the ansys hfss software as follows. table 2. calculation of the rcs on the ucav saccon model freq [ghz] i wave theta [deg] i wave phi [deg] monostatic rcs total [db] 10 90 0 -17.8039 10 90 15 -39.4049 10 90 30 -33.3534 10 90 45 -33.5918 10 90 60 -46.8229 10 90 90 -58.5062 10 90 120 -47.3148 10 90 150 -35.1005 10 90 180 -17.7782 10 90 270 -35.4863 10 90 360 -17.8039 from the simulation results and the calculation of the radar cross section (rcs) value above, the average rcs value is -38.9633 db or equivalent to 0,0039 m . this rcs value is quite small for the ucav class in general, so for reconnaissance missions or air defense security this platform is very suitable for use as a defense tool. from the results of the rcs simulation in figure 10 which is a linear plot related to the effect of the incident wave on the azimuth plane to the rcs value, it shows that the rcs value experienced a spike in the graph at several points. these points cause a spike in the rcs value at approximately -5° to 5°, 30° to 45°, 145° to 150°, 210° to 215° and 315° up to 320°. these points are in the azimuth plane which is the point that has the highest rcs value where when viewed on the ucav platform these points are located on the front of the ucav platform or nose, the side of the ucav and on the tail of the ucav. this is what needs to be analyzed in more depth for the shaping technique at the time of the ucav design that in order to reduce the rcs value the things that must be considered and prioritized in shaping are the nose of the ucav, the wings and tail of the ucav. 4. conclusions the unmanned combat aerial vehicle (ucav) model used is a generic ucav configuration developed by the nato sto/avt-161 task group, which is named saccon ucav. the main reason for choosing this ucav platform is because the geometry of the saccon ucav platform has been designed with stealth requirements which lead the ucav design to the flying wing concept. the basic lambda-shaped geometry of the saccon ucav configuration is also oriented towards the typical goal of low observability with a combination of high agility and high angle of attack (aoa) capabilities, so that in addition to considering low capabilities detected by enemy defense radars, this saccon ucav model was also developed as a realistic ucav concept. the results of the saccon ucav design were then analyzed by the rcs value using the sbr method using the ansys hfss software. from the simulation results and the calculation of the radar cross section (rcs) value above, the average rcs value is -38.9633 db or equivalent to 0,0039 m . from the results of the rcs simulation in figure 10 which is a linear plot related to the effect of the incident wave on the azimuth plane to the rcs value, it shows that the rcs value experienced a spike in the graph at several points. these points cause a spike in the rcs value at approximately -5° to 5°, 30° to 45°, 145° to 150°, 210° to 215° and 315° up to 320°. these points are in the azimuth plane which is the point that has the highest rcs value where when viewed on the ucav platform these points are located on the front of the ucav platform or nose, the side or side of the ucav and on the tail of the ucav. this is what needs to be analyzed in more depth for the dss vol. 3, 2022, pp.74-82 82 shaping technique at the time of the ucav design that in order to reduce the rcs value the things that must be considered and prioritized in shaping are the nose of the ucav, the wings and tail of the ucav. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] n. pramadi, radar and stealth, jakarta: pena nusantara, 2019. 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[13] c. m. liersch et al. “multidisciplinary design and aerodynamic assessment of an agile and highly swept aircraft configuration” ceas aeronaut, p677–694, 2016. microsoft word 15-21_185 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.15-21 https://doi.org/10.37868/dss.v3.id185 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 15 perturbed t-shaped patch antenna with slits and a floating metal for 5g. erol terović1*, şehabeddin taha i̇meci2 1, 2 electrical and electronics engineering, faculty of engineering and natural sciences, international university of sarajevo, hrasnicka cesta 15, 71210 ilidza, bosnia and herzegovina *corresponding author e-mail: erolprivate@gmail.com, simeci@ius.edu.ba received: mar. 6, 2022 revised: jun. 3, 2022 accepted: jun. 20, 2022 online: jun. 24, 2023 abstract this research paper highlights the process of designing and simulating a novel antenna. our antenna is meant to be used in 5g applications (sub-6 ghz). simulating and designing were done using the sonnet suites software. the substrate used in our antenna is a 1.55 mm thick fr-4 substrate, that has a εr of 4.4. the antenna center frequency is 4.06 ghz. at the center frequency, s11 is 39.46 db. furthermore, the antenna has an e-𝜃 of 5.75 db, and e-φ of -9.99 db. this antenna can be used in devices that use 5g technologies. this antenna has the benefit of being cheap to produce while boasting good performance during operation. © the author 2022. published by arda. keywords: antenna, 5g, fr-4, microstrip, sonnet suites 1. introduction in the past few years, more and more research has been conducted in the field of mm-wave technology, to be employed in 5g systems. due to the elevated interest in 5g, there has been a demand for multi-band minituarized antennas that will serve systems that operate in lower ghz bands (sub 6 ghz). 5g will satisfy the requirements for lower time delays, iot, small size and high data rates [1]. 5g will support faster communications in the mobile department, while at the same time providing a high speed data rate. antennas are needed that can be used for stable and disturbance free communications, while having an improved bandwidth, power, gain and insensitivity to noise. due to this, unique solutions are needed for designing antennas [2]. most modern systems for mobile communication have become widely used after the 2000s. they have progressed at a most rapid pace alongside other technologies over the past three decades. initially it began with the 1g which was analog-based. and then progressed to the fourth generation. the fourth generation is an ip based technology (4g). lte-a (long term evolution advanced) is becoming redundant due to an extreme increase in demand for data, which is caused by a surge in smart devices (iot) [3]. designing a transciever for 5g applications can pose numerous challenges. considering that the antenna is one of the most critical element of a 5g system, therefore it has a crucial role in the determination of the whole performance of the system. there are several requirements for antennas for 5g systems: first and foremost, it has to maintain a small size in order to provide a simple and effortless integration with the frontend. furthermore, keeping the design compact is essential in orfer to make the antenna compatible for array based configurations when dealing with dss vol. 3, 2022, pp.15-21 16 a mimo architecture [4]. most commonly used of all microstrip patch antennas, are rectangular patch antennas, although circular patch antennas are also commonly used [5]. advantages of microstrip patch antennas include low cost, low profile, low cost, suitable for array implementation etc. however some significant disadvantages include the low gain, narrow bandwidth and relatively large size for low frequencies [6]. microstrip patch antennas are a great option for sub-6 ghz uses, owning to their superb rf and mw characteristics. a patch antenna is essentially a substrate that has one side occupied with a metal conductor and the flip side is consisted of a ground plane made of conductive materials [7]. microstrip patch antennas can be fed using different ways. these ways include a microstrip line feed, coaxial feed, aperture coupled feed and proximity coupling [8]. although, the most commonly used feeding way is microstrip line feeding, due to it’s simple nature. thus, the antenna in this paper will also use a simple microstrip line feed. the antenna was designed in and simulated in sonnet® suites™ program by sonnet software, which is implemented using a method-of-moments (mom) em analysis, which in turn is based on maxwell’s equations [9]. numerous other designs have been proposed by other works, for antennas exist that allow the implementation of dual band capabilities [10], in our case the antenna is a mono band antenna. another paper demonstrates how to implementat a metamaterial inspired antenna [11]. our antenna is a single antenna, but could potentially be implemented in an array configuration, which is demonstrated in a paper which describes a circular array antenna for wlan and 5g applications [12] alongside a paper which explains the process of implementing a miniaturized antenna array for 5g [13]. numerous wideband examples have also been proposed, such as a paper that demonstrates a low-band wideband microstrip antenna for 5g [14]. unlike some designs, such as the uwb patch antenna for sub-6 ghz communications [15] or the wideband small fractal antenna for 5g sub-6-ghz communications [16] which have a defected or partial ground plane, but instead has a full ground plane. we chose fr-4 as the substrate due to its wide availability and low cost, but other authors have used for instance rt/duroid 5880 substrate which has a lower dielectric loss for better bandwidth and higher efficiency [17]. rt/duroid 5880 has a εr of 2.2 which is better compared with the value for fr-4, which is 4.4 [18]. due to the smaller dielectric constant, the bandwidth of the antenna increases because they are inversely proportional [19]. due to inevitable manufacturing errors and tolerances, along with feed line soldering and an inaccurate value of relative dielectric permittivity, if we were to manufacture the antenna, our simulated results would not precisely match up with the experimental ones [20]. the antenna was simulated and iteratively improved by observing the filter parameters in each iteration. 2. research method the final proposed antenna design can be seen in figure 1. in section 3 of this paper, we can read about the iterative process and steps that led us to this final iteration of the design. a stub was added to improve the antenna’s gain. the overall size is 36.5 x 39.75 mm, so it can be said that the antenna is a relatively compact design, with a center frequency of 4.06 ghz, for the simulation the parameters were chosen so the sweep is from 2 to 6 ghz. the cell size for the simulation was 0.25 in both x and y directions. the dielectric thickness is 1.55 mm, with a relative dielectric permittivity of 4.4. the topology of the filter can be seen in figure 1, while the 3d layout of the design is visible below, in figure 2. the design is single sided, with no defected ground plane. the design has been labeled with the letters a to e, along with dimensions. the letters are markers that indicate points of interest for our parametric study, in the section 3, we can see the results of our parametric study, and through them we can see the way the iterative improvement process has worked. dss vol. 3, 2022, pp.15-21 17 in figure 3 we can see the current density visualization of the antenna. the current is crowded in the center square and l-shaped metals. figure 1. antenna topology figure 2. 3d antenna topology figure 3. current density plot 3. results and discussion figure 4 shows the reflection coefficient graph. the goal was to get the s11 magnitude to be lower or equal to -10 db. can be seen in figure 4. 4.06 ghz is the antenna’s center frequency, with a s11 reflection coefficient of -39.46 db. in figure 5, we can see the polar graph of e-𝜃 (db) and e-φ (db), in red and blue respectively. the requirement was set to be that e-𝜃 should be larger or equal to 5 db, while e-φ lower than or equal to -5 db. dss vol. 3, 2022, pp.15-21 18 figure 4. graph of s11 reflection parameter figure 5. polar plot for antenna as mentioned previously, the antenna was designed in stages, with each state’s results being used in the next stage, to finally achieve a workable design that has a good balance of size, optimal parameters and complexity. the first parametric study’s results are visible in table 1, the “a” rectangle (for legend, see figure 1.) was incrementally increased in size by 0.5 mm. for each increase (s11) that was in the range of (-10db, infinity) in the antenna center frequency, and near 0 in all other areas. once we have selected the best version, which in this case was the one with a length 4 mm. we move on to the next phase and begin doing the parametric study for rectangle b. dss vol. 3, 2022, pp.15-21 19 table 1. results of the first parametric study for the second parametric study, rectangle b was changed by 0.5 mm. in the end with all parameters considered, the case where the length is 5 mm was chosen, and the process moved on to the next stage. the results are outlined below in table 2. as we can see based on these results, the case that has a rectangle length of 5mm was chosen as the one that will be used in the following iterations of the design process. it was chosen because it is the best one, according to the parameters. table 2. results of the second parametric study length of rectangle b s11 (db) e-𝜽 (db) e-𝚽 (db) frequency (ghz) 2 -10.28 5.61 -9.53 4.06 2.5 -11.75 5.63 -9.52 4.06 3 -13.39 5.64 -9.5 4.06 3.5 -15.48 5.65 -9.48 4.06 4 -18.55 5.56 -9.48 4.06 4.5 -20.84 5.67 -9.47 4.06 5 -24.24 5.57 -9.47 4.06 5.5 -18.66 5.69 -9.51 4.06 in the third parametric study, we have modified the size of the two side rectangles simultaneously, and the results were measured, this is the first time where some invalid results were obtained, we have a few different cases. for example, for the case where we had the length 12.5 mm, the result is invalid because we had a multiband antenna, with two transmission frequencies, which was not our goal for this paper. the chosen case was 15 mm. table 3 contains the results of this parametric study. table 3. results of the third parametric study length of rectangle c s11 (db) e-𝜽 (db) e-𝚽 (db) frequency (ghz) 0 -23.41 5.61 -7.41 4.06 2.5 -24.04 5.63 -7.34 4.06 5 -23.66 5.63 -7.4 4.06 7.5 -23.57 5.63 -7.4 4.06 10 -22.1 -5.57 -6.72 4.06 12.5 not valid two frequencies 15 -39.46 5.75 -9.99 4.06 17.5 -31.31 5.69 -9.12 4.06 20 -22.52 5.62 -8.08 4.06 22.5 -27.38 5.68 -9.58 4.06 25 -37.03 5.69 -9.14 4.06 length of rectangle a s11 (db) e-𝜽 (db) e-𝚽 (db) frequency (ghz) 1 -15.5 5.62 -9.55 4.06 1.5 -13.91 5.62 -9.5 4.06 2 -12 5.61 -9.24 4.06 2.5 -10.15 5.68 -9.98 4.06 3 -12.07 5.67 -9.85 4.06 3.5 -14.71 5.66 -9.69 4.06 4 -16.84 5.66 -9.48 4.06 4.5 -14.38 5.66 -9.21 4.06 5 -10 5.66 -7.26 4.06 dss vol. 3, 2022, pp.15-21 20 in the fourth parametric study, we observed the parameter's differences when changing the position of the gap where the d marker is placed. however, this case produced a lot of invalid results, mostly due to s11 being over -10 db. due to the results not being very useful, the previous iteration was left unchanged. the results are visible below in table 4. table 4. results of the fourth parametric study length of rectangle d s11 (db) e-𝜽 (db) e-𝚽 (db) frequency (ghz) 4 -10.87 5.39 -8.69 4.22 6 -19.99 5.78 -10.14 4.04 8 invalid 10 -12.38 5.69 -12.18 3.98 12 invalid 14 invalid 16 invalid for the fifth and final parametric study, the gap marked by the letter e was adjusted and the results are visible below in table 5. in this case, the best results overlap with the best result from parametric study 3, therefore nothing changes, and we have our final design. which is the one shown in the figures above. table 5. results of fifth parametric study length of rectangle e s11 (db) e-𝜽 (db) e-𝚽 (db) frequency (ghz) 4.25 -39.46 5.75 -9.99 4.06 5.25 -13.07 5.68 -9.04 4.12 6.25 -10.02 5.56 -7.93 4.16 7.25 -14.97 5.45 7.6 4.22 8.25 -25.62 5.29 -7.15 4.28 9.25 -17.31 5.1 -6.76 4.34 4. conclusions in this paper, we have presented a microstrip patch antenna design, along with designing and simulating it. the antenna shows good performance according to the simulations. alongside this, it is simple, compact, and cheap to manufacture, owing to the relatively low-cost fr-4 substrate. our antenna was simulated within a range of 0 to 6 ghz. several parametric studies have been done regarding the overall antenna shape with the goal of improving the antenna behavior. by changing the geometry incrementally and observing changes, an optimal design was found, and it had the following parameters: the antenna center frequency is 4.06 ghz. at the center frequency, s11 is -39.46 db. furthermore, the antenna has an e-𝜃 of 5.75 db, and e-φ of -9.99 db. 5g technologies are exploding around us, and antennas are a key element in making them work. this paper has demonstrated the procedure behind designing and simulating such an antenna. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] s. islam, m. zada, and h. yoo, “low-pass filter based integrated 5g smartphone 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[14] w. an, y. li, h. fu, j. ma, w. chen, and b. feng, “low-profile and wideband microstrip antenna with stable gain for 5g wireless applications,” ieee antennas and wireless propagation letters, vol. 17, no. 4, pp. 621–624, apr. 2018, doi: 10.1109/lawp.2018.2806369. [15] x. tang et al., “ultra-wideband patch antenna for sub-6 ghz 5g communications,” 2019 international workshop on electromagnetics: applications and student innovation competition (iwem), sep. 2019, doi: 10.1109/iwem.2019.8887933. [16] s. n. r. rizvi et al., “wideband small fractal antenna with simple design strategy for 5g sub-6-ghz wireless communications,” ieee xplore, pp. 1–4, aug. 2021, doi: 10.23919/ursigass51995.2021.9560122. [17] j. colaco and r. lohani, “design and implementation of microstrip patch antenna for 5g applications,” ieee xplore, pp. 682–685, jun. 2020, doi: 10.1109/icces48766.2020.9137921. 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[20] a. khan and r. nema, “analysis of five different dielectric substrates on microstrip patch antenna,” international journal of computer applications, vol. 55, no. 14, oct. 2012, doi: 10.1.1.244.7807. microsoft word 106-112_211 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.106-112 https://doi.org/10.37868/dss.v3.id211 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 106 laminar composite materials for unmanned aircraft wings mala utami1*, jonathan ernest sirait2, beny budhi septyanto3, aries sudiarso4, i nengah putra apriyanto5 1,2,3 faculty of defense technology, indonesian defense university, indonesia *corresponding author e-mail: mala.utami@tp.idu.ac.id received: nov. 15, 2022 revise: dec. 2, 2022 accepted: dec. 21, 2022 online: dec. 24, 2022 abstract unmanned aerial vehicles (uavs) have high popularity, especially in the military field, but are now also being applied to the private and public sectors. one of the uav components that require high material technology is the wing. the latest material technology developed as a material for unmanned aircraft wings is a composite material that has high strength and lightweight. this research aims to identify composite materials that can be used for unmanned aircraft wing structures. the method used in this research is a qualitative method with a literature study approach. the results of this theoretical study show that some of the latest composite materials that have been developed into materials for unmanned aircraft wings are laminar composites with a sandwich structure. laminar and sandwich composites consist of various constituent materials such as balsa wood fiber-glass and polyester resin, microparticles, carbon fibre reinforced polymer, polymer matrix composites reinforced with continuous fibers, polymer matrix composites, e-glass/epoxy, kevlar/epoxy, carbon/epoxy, woven fabrics, acrylonitrile butadiene styrenecarbon (abs) laminated with carbon fiber reinforced polymer (cfrp) and uniaxial prepreg fabrics. laminar and sandwich composite materials are a reference for developing unmanned aircraft wing structures that have resistant strength and lightweight. © the author 2022. published by arda. keywords: uav wings, composite materials, laminar composites, sandwich composites 1. introduction an unmanned aerial vehicle (uav) can be defined as a type of aircraft that is not controlled by a pilot, but uses aerodynamic forces with a lift so that it can fly autonomously or be remotely controlled, can be recovered or disposed of, and can carry payloads that can be tailored to the desired task and operation [1]. uavs are increasing in use for both civilian and military use and are preferred because they are more cost-effective and more versatile. so in the last few decades uavs have become very popular due to their versatility [6]. currently, unmanned aerial vehicles (uavs), or in indonesia known as unmanned aircraft (drones) have high popularity so the development of good materials at a low price becomes a goal. not only that but designing uavs also requires engineers to design and produce on a large scale with limited time [3]. the development of uavs in the aviation industry is to find materials or materials that have high speed. the advancement of uavs is highly dependent on innovations in various technologies such as control systems, computer technology, and communication integration. innovations in manufacturing techniques and materials are also important to develop and improve uavs’performances by producing durable and lightweight dss vol. 3, 2022, pp.106-112 107 structures. this can be achieved by applying innovative composite materials with high strength, ballistic and rigid properties. advanced composite materials are made of fibrous materials embedded in a resin matrix, generally laminated with fibers oriented in alternating directions to form the strength and stiffness of the combined material [3]. wing development for unmanned aerial vehicles (uavs) is a multi-stage work such as airfoil selection, geometric calculation, structural design, material selection, numerical analysis, and manufacturing. the main objective in wing development is to design a structure characterized by high strength and low weight. the wing should have a high strength ratio and be supported by lightweight. there will be loads and moments acting on the wing so to overcome the stress due to these loads the wing must have high strength. the weight or weight of the wing must be low because the heavyweight will reduce unwanted efficiency in the engine [3]. with the development of material technology, it is easy to access and purchase composite materials. with the advancement of composite manufacturing technology, to make even complex shaped parts can be made easily in a few days. the use of uav composite materials is different from that of general aviation vehicles, where most of the structures are made of aluminum and titanium in addition to carbon fiber composites. whereas almost all uav structures are made of carbon fiber composites [2], it becomes possible to manufacture a uav in a laboratory or workshop for 4 or 5 people in a few weeks. in addition, maintenance and repair of uavs can also be done quickly and easily because they are assembled from small, cheap, and easy-to-manufacture composite components. composite materials offer an excellent strength-to-weight ratio with greater manufacturability of complex parts, unique contours, and special features, especially in aircraft applications. one of the basic aircraft components of concern in the application of composite material structures is the wing profile [6]. figure 1. comparison of stiffness and strength with a weight between composite materials [4] dss vol. 3, 2022, pp.106-112 108 in the selection of composite materials for uavs that have high criteria, it means that the selected material must have resistant strength and be lightweight. for example, polymer matrix composites reinforced with continuous fibers are a good choice. these materials are characterized by young's modulus values twice as high as those of aluminum alloys and twice as lightweight [5]. the difficulty of using composite materials lies in the structure, the use of composite materials requires knowledge of material constants and mechanical properties. correctly defining the characteristics of the composite material will guarantee that the material can be a good structure and have the desired reliability of results. the use of composites in aircraft is increasing day by day, especially in military aircraft. composite materials have the advantages of high strength and lightweight which are very well applied to complex parts, unique contours, and special features, especially as aircraft materials. one aircraft component that is very suitable for using composite materials is the wing profile. therefore, this paper raises the issue of the use of composite materials in unmanned aerial vehicles (uavs), especially on the wings. this paper is a theoretical study that aims to increase the knowledge of authors and readers in material engineering technology and its application in the military. 2. research method this research uses a qualitative method with a literature review approach. the discussion or analysis is carried out based on the works of research results related to the topic and the results of thoughts that have been produced by researchers and practitioners. the literature review is one of the techniques that can be used in research. a literature review has its own difficulties when compared to other research techniques. as it requires a high understanding of the researchers in conducting a study of a problem to be solved related to the theory to be used, and the model or method to be carried out. the stages in this literature review research are as follows. a. finding and determining relevant literature, this activity requires high focus and shrewdness in finding data sources, especially secondary data. journals, articles, and books are the main sources in this research, the more sources used, the better the results obtained. b. conducting literature screening, at this second stage, the researcher must be able to filter the selection of sources that have been obtained to be used in problem-solving. of the many sources obtained, they are evaluated to adjust to the objectives of the research to be achieved. c. strengthening the topic with the sources that have been obtained, at this stage, this is the level of difficulty in the literature review because it must be able to strengthen existing theories with sources and discuss gaps in the form of advantages or disadvantages of each source. d. conclude based on the outcome of the discussion so as to reach a solution to the problem raised. 3. results and discussion the definition of composite material is a material consisting of two or more phases with significantly different properties (physical and chemical). combined together to form a new material with different characteristics from its components. the resulting composite material properties are beneficial properties that cannot be achieved with one phase/component alone. and what is unique is that each component remains separate in the finished structure [3]. one of the most common examples of composites is fiber-reinforced composite materials that consist of high-strength and modulus fibers in a matrix material. reinforced steel bars embedded in concrete provide an example of fiber-reinforced composites. in a composite, the function of the fiber is to carry the load exerted on the composite structure and provide stiffness, strength, thermal stability, and other structural properties. while the matrix material serves as a component that binds the fibers together, transfers fiber loads, and provides protection to reinforce the fibers against chemical attack, mechanical damage, and other environmental effects such as moisture and others [6]. the composite industry has grown rapidly with the advent of better plastic resins and good reinforcing fibers. as dupont developed the aramid fiber known as kevlar, it has become a standard in armor due to its high ductility. in addition, carbon fibers were also developed so since this time composites have become a dss vol. 3, 2022, pp.106-112 109 substitute for metals as a new material. at present, of course, the composite industry continues and is still growing, its growth as a metal replacement material as an aircraft material, especially in unmanned aircraft [7]. composites have unique advantages over other monolithic materials such as high strength properties, high stiffness, durable life, low density, and adaptability to the structure being created. in addition, recent composite materials are exploring improvements such as corrosion resistance, wear resistance, appearance, temperature-dependent properties, thermal stability, thermal insulation, thermal conductivity, and acoustic insulation. the basis that makes composite materials have superior structural performance lies in the high specific strength (strength to density ratio) and high specific stiffness (modulus to density ratio) and the anisotropic and heterogeneous character of the material. the anisotropic and heterogeneous character also provides the freedom to design structures with optimal configurations to obtain certain functions [8]. composite materials can be classified into several types, namely [9]: a. first classification, based on matrix constituents. organic matrix composites (omcs), metal matrix composites (mmcs), and ceramic matrix composites (cmcs). the term organic matrix composites are generally assumed to cover two classes of composites, namely polymer matrix composites (pmcs) and carbon matrix composites commonly referred to as carbon-carbon composites. b. the second classification refers to reinforcement. fiber reinforced composites, laminar composites, and particulate composites. c. fiber reinforced composites, are composites in which fibers as reinforcement are embedded in the matrix material. these composites are called discontinuous fiber composites or short fiber composites with properties that vary depending on the length of the fiber. d. laminar composites, composites consisting of material held together by a matrix. sandwich structures fall under this category. e. particulate composites, composites consisting of particles distributed or embedded in the matrix body. the particles are in the form of flakes or powders. article board, concrete, and wood are examples. in its application as a leading material in uavs, especially wings, ceramic materials used are various as described above. based on research conducted by lamaini et al., [10] the sandwich structure made consists of balsa wood, fiberglass, polyester resin, and microparticles used to close the pores of the balsa wood surface. the results of the mechanical properties analysis of the uav wing structure can be seen in that the sandwich structure can be used in uav applications. the developed uav wing weighs 800 grams, 20 mm camber thickness with a length of 20 mm and a span of 70 mm. tensile, compressive, and flexural tests have been carried out on the sandwich structure. the results of the average tensile and compressive properties of the composite can compete with existing composite materials. the lay-up method can cost production and can also be used in large-scale production. so it can be concluded that balsa wood-based sandwich composites can be used as uav wing structures. all main components in the aircraft are made of cfrp (carbon fibre reinforced polymer) composite material consisting of woven and uniaxial prepreg fabrics. uniaxial prepreg fabrics aim to ensure volume consistency and will provide a smooth overlap. a low-cost manufacturing process can be achieved by reducing the number of parts and a fabrication process that does not require costly autoclaving. the characteristics obtained from the test results of the uav wing structure with composite materials are the shaker-table approach to simulate the wing on the uav. the shaker-table method produces a signal of greater magnitude with less noise when compared to data obtained from a full aircraft configuration [11]. table 1 shows previous research on material utilization for uav wings, with authors, titles, methods and type of composite materials given. dss vol. 3, 2022, pp.106-112 110 table 1. previous research on material utilization for uav wings author (year) title methods composite material lamani, shivaji., stanvil dsouza, dane hubert saldanha, granvil dsouza and madhurima r londhe. (2020) [10] analysis, fabrication and testing of a sandwich composite for an uav wing hand lay-up technique sandwich composite (fiberglass and polyester resin and microparticles) j. simsiriwong & r. warsi sullivan. (2012) [11] experimental vibration analysis of a composite uav wing the form of woven and uniaxial prepreg fabrics carbon-fiber reinforced polymer (cfrp) composite basri, e. i., sultan, m. t. h., m., f., basri, a. a., abas, m. f., majid, m. s. a., ahmad, k. a. (2019) [12] performance analysis of composite ply orientation in aeronautical application of unmanned aerial vehicle (uav) naca4415 wing ply combinations carbon fiber reinforced polymer (cfrp) laminated composite grodzki, w., & łukaszewicz, a. (2015) [3] design and manufacture of unmanned aerial vehicles (uav) wing structure using composite materials. polymer matrix composites reinforced with continues fibers, polymer matrix composites (laminates and sandwich structures) tah’ir turgut (2007) [6] manufacturing and structural analysis of a lightweight sandwich composite uav wing vacuum bagging method with curing at room temperature laminated composite and sandwich structure (eglass/epoxy, kevlar/epoxy, carbon/epoxy) sasi kirono (2015) [13] mechanical properties of unmanned aircraft composite materials a comparison of the mechanical properties of composite materials is carried out by tensile strength testing. front fuselage components upper skin with three layers of carbon fiber, honeycomb, and glass fiber vasić, zoran, stevan maksimović, and dragutin georgijević (2018) [14] applied integrated design in composite uav development pyrolysis of an organic precursor such as rayon or poly-acrylonitrile, or petroleum pitch graphite fibers, glass, carbon and graphite, kevlar, boron and carbon fibers according to research conducted by basri et al., [12], the acp (ansys composite preppost) module is used to apply composite materials with various thicknesses and angles. which is applied to wing skins, spars, and ribs. laminate composite is prepared according to the classical laminate theory (clt) to investigate the dss vol. 3, 2022, pp.106-112 111 behavior of composite sandwich structures subjected to internal influences from applied loads. in ansys, the model of a wing structure is interpreted in the form of shell elements (lamina). the effect of ply orientation on the naca 4415 uav wing composite laminate was evaluated. analytical predictions show that the stress state developed in the variation of fiber orientation with ply-angle has a significant influence on the strength. finite element analysis studies show the total displacement values obtained are within the acceptable range. unmanned aerial vehicle (uav) wings according to their purpose vary in airfoil shape, thickness, chord dimension, span, surface area, and geometry. despite the differences, the design concept is similar to all types of structures. due to the high requirements of modern uav (high-strength-low-weight) composite materials, especially polymer matrix composites reinforced with continuous fibers are the most appropriate choice. to transfer such loads, composite structures have been designed. the first proposed structure is a laminated composite consisting of glass cloth (outer) and unidirectional carbon cloth (inner) reinforced with balsa wood ribs for proper shape. the construction made is a type of sandwich structure, since the upper and lower layers of fabric are separated with balsa wood ribs. the second analysis structure is characterized by an additional foam core separating the glass-carbon fabric layers. numerical analysis of composite structures based on the same boundary conditions showed that the sandwich structure is characterized by the deflection of the foam core layer under the load of 11.34 mm 3 times smaller than the carbon fiber laminate deflecting 32.16 mm considering the same weight. lightweight composite structures based on carbon, glass fibers produced by the vacuum bag technique minimize the creation of voids (bubbles and wrinkles) and allow to obtain of high fiber content which translates into higher strength of the created structures [3]. according to research by vasić et al [15] composites with graphite fiber materials are the strongest and stiffest materials widely used in unmanned aircraft structural systems. placing fibers in graphite composites, it will increase the strength and stiffness of the composite material. tensile testing of coupon specimens was conducted to obtain the modulus of elasticity of the composites used in the uav. the elastic properties obtained from the mechanical tests were used in the elemental analysis of the uav wing. the woven fabric was modeled as a 2-d orthotropic layer in the analysis. in addition to mechanical testing, elastic properties were also obtained by two other methods. one method is the composite micromechanics approach. in this approach, the properties are obtained based on the volume fraction of the constituents and their respective mechanical properties. the woven fabric is modeled as a biaxial cross-ply laminate in the analysis. another method used to derive elastic properties is the approximate approach. this approach is based solely on the rule of mixtures. in this case, the woven fabric is also modeled as a 2-d orthotropic layer. it can be concluded from the results of the full-wing analysis that the three material definitions used to give consistent and acceptable results. moreover, if the displacement results are observed, it is clear that they are almost the same [10]. research has been conducted by galatas et al [15] using the latest sandwich composite structure consisting of acrylonitrile butadiene styrenecarbon (abs) laminated with carbon fiber reinforced polymer (cfrp) layer with abs/cfrp/abs arrangement. a series of tests were conducted with tensile measurements for 3d printed samples with varying filler densities and cfrp layers. the results showed that the abs/cfrp/abs sandwich structure during the tensile tests exhibited brittle properties while it was ductile for the monolithic abs samples. 4. conclusions laminar composites type composite material with sandwich structure is the latest composite material and is widely applied as a uav wing structure. laminar composites and sandwiches consisting of various materials such as balsa wood fiberglass and polyester resin, microparticles, carbon fiber reinforced polymer, polymer matrix composites reinforced with continuing fibers, polymer matrix composites, e-glass/epoxy, kevlar/epoxy, carbon/epoxy, woven fabrics, acrylonitrile butadiene styrenecarbon (abs) laminated with dss vol. 3, 2022, pp.106-112 112 carbon fiber reinforced polymer (cfrp)and uniaxial prepreg fabrics. this laminar-type composite material with a sandwich structure has good test values and can be used as a uav wing structure material. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] us department of defense, “dictionary of military and associated terms”, joint publication 1-02. [2] hexcel corporation. unmanned aerial vehicles (uavs). retrieved from https://www.hexcel.com/resources/uav#:~:text=today%2c%20almost%20all%20uav%20structures, addition%20to%20carbon%20fiber%20composites. diakses pada 28 agustus 2022. [3] grodzki w., łukaszewicz a. (2015), “design and manufacture of unmanned aerial vehicles (uav) wing structure using composite materials”. materialwissenschaft und werkstofftechnik, 46(3), 269–278. doi:10.1002/mawe.201500351. [4] http://www-materials.eng.cam.ac.uk/mpsite/interactive_charts/spec-spec/ns6chart.html [5] ch. kassapoglou, “design and analysis of composite structures with applications to aero-space structures”, wiley, 2013. [6] t. tah’ir, “manufacturing and structural analysis of a lightweight sandwich composite uav wing”. thesis. middle east technical university, 2007. [7] s. k. mazumdar, “composites manufacturing: materials, product, and process engineering”. crc press, 2002. [8] i. m. daniel, o. ishai, “engineering mechanics of composite materials”. oxford university press, 1994. [9] r. r. nagavally, composite materials history, types, fabrication techniques, advantages, and applications”. proceedings of 29th irf international conference, 2016. [10] s. lamani, s. dsouza, d. h. saldanha, g. dsouza, m. r. londhe, “analysis, fabrication and testing of a sandwich composite for an uav wing”. 3rd international conference on frontiers in automobile and mechanical engineering (fame 2020). doi:10.1063/5.0033993, 2020. [11] j. simsiriwong, r. w. sullivan, “experimental vibration analysis of a composite uav wing”. mechanics of advanced materials and structures, 19(1-3), 196–206. doi:10.1080/15376494.2011.572248 2012. [12] e. i. basri, m. t. h. sultan, m. f. basri, a. a. abas, m. f. majid, m. s. a. ahmad, “performance analysis of composite ply orientation in aeronautical application of unmanned aerial vehicle (uav) naca4415 wing”. journal of materials research and technology. doi:10.1016/j.jmrt. 2019.06.044. 2019. [13] k. sasi. (2015). “sifat mekanis material komposit pesawat udara tanpa awak”, retrieved from: http://repositori.lapan.go.id/525/1/bunga%20rampai_sasi%20kirono_bppt_2015.pdf, 28 august 2022. [14] z. vasić, s. maksimović, d. georgijević, "applied integrated design in composite uav development." applied composite materials 25.2: 221-236, 2018 [15] a. galatas, h. hassanin, y.zweiri, l. seneviratne. "additive manufactured sandwich composite/abs parts for unmanned aerial vehicle applications." polymers 10, no. 11: 1262, 2018. microsoft word 20-28_204 (online) issn 2744-1741 defense and security studies original research vol. 5, no. 1, 2024, pp. 20-28 https://doi.org/10.37868/dss.v5.id204 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 20 sub-6ghz hand pump shaped microstrip antenna for 5g communication adnan ahmetović1*, şehabeddin taha imeci2, bilal tütüncü3 1 electrical and electronics engineering, faculty of engineering and natural sciences, international university of sarajevo, bosnia and herzegovina 2 college of engineering and technology, american university of the middle east, kuwait 3 electrical and electronics engineering, faculty of engineering, van yüzüncü yıl university, van, turkey *corresponding author e-mail: adnan.ahmetovic0@gmail.com received: dec.10, 2023 revised: feb. 1, 2024. accepted: mar. 3, 2024 online: mar. 8, 2024. abstract the purpose of this paper is to explore the presented design of a hand-pump shaped microstrip antenna pfor sub-6ghz 5g communication. this paper will first provide a brief overview of the antenna design and its capabilities. meaning, overall impressive dimensions of 25.25 mm x 20.75 mm x 1.55 mm, with s11 being -16.82 db at operating frequency of 5.16 ghz. next, the paper will discuss the design of the antenna and how it can be optimized with sub 6 ghz operating frequency, along with requirements. to reach required specifications, inc. e-𝜃 ≥ 5 ghz ≥ e-φ; s11 ≤-10, various geometrical parameters, among others, have been tested, resulting in two slots being added (slot a and slot b), in combination with various slits. finally, antenna is produced, and laboratory measurements are carried out for the validation of results. further discussing potential benefits and drawbacks of using this antenna design for 5g applications. © the author 2024. published by arda. keywords: hand-pump antenna, 5g, antenna analysis, sonnet software 1. introduction 5g networks operate in a higher frequency range than previous generations, allowing for faster speeds and more capacity. 5g signals are able to travel further and penetrate buildings better than previous generations, making it ideal for coverage in dense urban areas. 5g technology is also more energy efficient than earlier generations, meaning that service providers can deploy more 5g base stations without increasing power consumption. in terms of frequencies used, the 3.4 ghz-3.8 ghz band is at the forefront of the sub-6 ghz spectrum. many countries see this band as a pioneer in realizing 5g technologies such as massive mimo arrays and antennas [1-3]. in recent literature, there has been significant interest increase towards microstrip antennas, inc. single element antennas, mimo antennas and arrays, for 5g application [4]. this paper is focused towards single element hand-pump shape microstrip patch antenna, using fr4 dielectric, which is known to have return loss is much lower compared to the other dielectric materials typically being used [5]. based on the researches, we can see that both square and rectangular shaped microstrip patch antenna offers satisfactory value of return loss (s11), that can be reduced by proper selection of material and shape of the antenna [6, 7]. antenna’s shape fine design usually includes various slits and slots, which alter antenna parameters, by change of current distribution, along with use of different thicknesses [8, 9]. based on the findings, we can conclude that using a substrate material with a greater dielectric constant degrades antenna performance while reducing antenna size. with increase of substrate thickness, the dss vol. 5, no. 1, 2024, pp. 20-28 21 resonance frequency results in decrease, in contrast to the bandwidth, which increases [10-11]. paper [12] even suggests use of u slotted patch, along air substrate, for better performance in terms of gain. however, focus of this paper will achievement of desired parameters, which includes specifical vertical and horizontal polarization required values (e-𝜃 ≥ 5 ghz ≥ e-φ), along with return loss (s11 ≤-10). most of the wireless networks such as 5g require multiband mimo-supported base station antennas and achieve this with use of multiple ports, supporting wider range of frequencies, leading to multiple arrays within one compact antenna enclosure [13-15]. paper [16] suggests employment of a single layer cross bow-tie dual-band tunable his (high-impedance surface) antenna designed for uhf band. there is also the potential use of a waveguide simulator to characterize approximately the performance of the proposed metamaterial structure [17]. patch array smart antennas can be used to arrange radiation patterns that cannot be achieved with a single patch element [18]. however, these structures of antennas require larger space, some have poor radiation efficiency and narrower bandwidth. therefore, the focus of this paper, along others (s11, e-𝜃, e-φ) will be achievement of wider bandwidth, smaller size, and high gain performance at lte 42/43 (3.4 ghz–3.8 ghz) band for 5g communication. this single band antenna is designed and analyzed in sonnet software [19], but also experimentally made. in addition, there is a lack of literature describing geometrical optimization of similar antennas. references [20] and [21] investigate the effect of the gap between radiating patches, but they do not take this into account to optimize the dimension parameters of a single-band antenna. 2. method figure 1. represents schematic diagram of the microstrip patch antenna, along with antenna dimensions. the design was created by joining together two rectangular shaped pieces. antenna has dimensions of 25.25 mm x 20.75 mm x 1.55 mm and it is fed up via port in the bottom right. this configuration provided the best current distribution results. design was created and simulated in sonnet software, later on produced and experimentally tested. initial design didn’t satisfy required specifications, in terms of reflection loss (s11), so slits on the bottom right part were added, they improved s11 drastically, but still the e-θ was not sufficient, showing value much greater than -5 db. to improve current distribution, along e-θ, a large slot in the middle was added, which resulted in value closer to the required -5 db, but not yet sufficient. furthermore, design was greatly improved, by detailed parametric analysis, resulting in two slots on the right, with one large slit in the middle, which, along dimension tweaking, provided sufficient results. more discussion along antenna dimensions can be seen in the parametric analysis part. figure 1. schematic diagram of the microstrip patch antenna dss vol. 5, no. 1, 2024, pp. 20-28 22 figure 2. represents 3d view of the antenna. it is noted that dielectric substrate material being used is fr4, with thickness of 1.55 mm. already mentioned antenna feeding line, width of 1mm is drilled, so that port could be attached. for simulation purposes, box size was selected to be 10x larger than antennas dimensions, resulting in size of 225 mm x 255 mm. in this means cell size was 0.25 mm x 0.25 mm, which was minimum, limited by universities r&d equipment, preventing any circular elements in antenna’s design, since they required smaller cell size to be properly design and simulated. figure 2. 3d view of the microstrip patch antenna 3. results data shown below represents parametric analysis of proposed design. a parametric analysis was carried out by varying the dimensions of length and width of various antenna parts, as well as dielectric thickness and erel value. analysis consists of 7 tables, where the first 3 tables represent size variations, table 4 being erel value (𝜀 in tables), table 5 dielectric thickness and table 6 and table 7 are combination of previously done variations, with goal of choosing best value for every parameter. table 1. represents size variation of a slot (a) (smaller slot on the right antenna side). it is noted that narrower slot design will result in s11 value fluctuation, with tendency to lower down, no matter the length. value of 3 mm x 0.75 mm provided e-φ increase, but significantly decreases s11 value, therefore dimension of 2 mm x 1 mm is chosen. table 1. size of the slot (a) dimension / mm s11/ db frequency / ghz e-φ / db e-θ / db 2 x 0.5 -13.71 5.26 5.362 -5.033 2 x 0.75 -13.85 5.26 5.372 -5.035 2.25 x 0.7 -13.63 5.26 5.382 -5.037 3 x 0.75 -12.81 5.24 5.414 -5.034 2 x 1 -13.90 5.26 5.384 -5.040 in table 2., various dimensions have been proposed for slot (b) (larger slot on the center part of the antenna), and it is noted that the length of the slot and s11 parameter are directly proportional, resulting in significant s11 value increase with length increase. although s11 value has greatly increased, this option was not suitable, because e-θ value fell down below required (-5 db), therefore, bolded dimensions were implemented. dss vol. 5, no. 1, 2024, pp. 20-28 23 table 2. size of the slot (b) slot-(b) size/mm s11/db frequency/ghz e-φ/db e-θ/db 1.25 x 8 -13.70 5.26 5.343 -5.040 1.5 x 8 -15.24 5.22 5.379 -4.956 1.5 x 8.5 -20.36 5.12 5.262 -4.859 2.5 x 8.5 -18.14 4.98 5.145 -4.705 2 x 8.5 -18.45 5.06 5.389 -4.651 table 3 represents results of various slit dimensions (side rectangle on the bottom right of the antenna). although some dimensions provided better e-φ and e-θ values, dimensions of 0.75 mm x 0.5 mm resulted in great s11 increase, hence it was more suitable. less than 0.5 mm almost always resulted in e-φ decreas, in this case s11, also decreased. table 3. size of the slits slits size/mm s11/db frequency /ghz e-φ/db e-θ /db 1 x 0.5 -13.90 5.26 5.384 -5.040 1.25 x 0.5 -11.89 5.26 5.410 -5.026 1.5 x 0.5 -10.12 5.26 5.422 -5.093 0.75 x 0.5 -15.56 5.26 5.344 -5.026 0.75 x 0.25 -14.92 5.26 5.290 -5.026 table 4. represents experimentation with erel value, it is noted that erel value of 4.6, although lowering the operating frequency of the antenna, increases both e-φ and e-θ, as well as s11, to -16.92 db. erel being lower than 4.4 results in e-θ decreasing below the required value of -5 db. table 4. erel value 𝜀 s11/db frequency/ghz e-φ/db e-θ/db 4.4 -15.56 5.26 5.344 -5.026 4.5 -15.04 5.2 5.263 -5.121 4.6 -16.82 5.16 5.350 -5.147 4.3 -15.17 5.32 5.401 -4.931 4.2 -14.57 5.38 5.440 -4.844 table 5. represents dielectric thickness fluctuation, while sticking to design default erel value of 4.2, note that any value less than 1.70 of diel. thickness results in s11 above -15 db, but any value lower than 1.55, reduces e-θ to less than -5 db. with this, we can neglect the benefits of increased e-φ and s11 and stick to the value of 1.55. table 5. dielectric thickness with erel value(4.2) dielectric thickness (𝜀 4.2) s11/db frequency/ghz e-φ/db e-θ/db 1.55 -15.56 5.26 5.344 -5.026 1.6 -13.87 5.38 5.415 -4.765 1.65 -13.31 5.38 5.393 -4.683 1.52 -15.02 5.38 5.456 -4.890 1.45 -15.99 5.38 5.499 -4.988 dss vol. 5, no. 1, 2024, pp. 20-28 24 in table 6., we can see that now with erel being value of 4.6, e-θ satisfies the requirements in every case, this provided ability to start experimenting with dielectric thickness more freely than before, hence value of dielectric thickness greater than 1.55 is not necessary, since it has negative result on s11, e-φ and e-θ. there is no need to lower down diel. thickness value, less than 1.55, since it satisfied the requirements, thicker dielectric layer can result in a more stable antenna design, while additionally increasing the power handling capability of the antenna. table 6. dielectric thickness with erel value(4.6) dielectric thickness (𝜀 4.6) s11/db frequency/ghz e-φ/db e-θ/db 1.55 -16.82 5.16 5.350 db -5.147 db 1.6 -15.96 5.16 5.327 db -5.076 db 1.65 -12.43 5.14 5.117 db -5.106 db 1.52 -17.26 5.16 5.365 db -5.188 db 1.45 -17.95 5.16 5.407 db -5.276 db hence the above, table 7 is representation of all the combined values, examining the s11 and radiation efficiency of the proposed antenna due to the optimized size parameters based on simulated results to achieve optimum values. table 7. final parameters with chosen values. parameter value s11 frequency e-φ e-θ dielectric thickness 1.55 mm -16.71 db (5.16 ghz) 5.333 db -5.180 db 𝜀 4.6 slot (a) 2 mm x 1 mm slot (b) 1.25mm x 8mm slit 0.75mm x 0.5mm 4. discussion s-parameters are shown below (figure 3.), specifically s11, representing reflection loss of the antenna. already mentioned goal was to achieve s11 value of ≤ -10 db, by this means s11 provided -16.71 db, as seen below. this implies an operational frequency of 5.16 ghz, with an operational bandwidth of exactly 60 mhz. furthermore, performance was studied with the help of antenna gain, current distribution, radiation pattern and radiation efficiency, specifical component shown in figure 4 and figure 5. figure 3. s-parameters of the microstrip patch antenna dss vol. 5, no. 1, 2024, pp. 20-28 25 vertical polarization component (e-θ ) is presented in figure 4. below, showing that e-θ is equal to -5.18 db, at its peak point (50°), in operational frequency (5.16 ghz). this graph was the main point of concern, at particular the moment, since reaching desired values required numerus geometrical changes in antennas design. figure 4. e-θ of the microstrip patch antenna horizontal polarization component (e-𝜑) is presented in figure 5. it implies that e-φ reaches 5.333 db, peak 5°. the presented simulation was done at frequency of 5.16 ghz. moreover, in figure 6. presenting far field with polar view including all curves together, it is noted that radiation pattern satisfied all the requirements. figure 5. e-φ of the microstrip patch antenna presented figure 6. considers all radiation pattern curves together in polar view, together with e-total represented in yellow color. red colored curve represents horizontal axis (e-𝜑), while vertical axis (e-θ) is represented in blue color. from the figure, the radiation pattern curves are close to symmetrical. additionally, the maximum radiation intensity is located at the theta=5°, showing 5.56 db e-total. dss vol. 5, no. 1, 2024, pp. 20-28 26 figure 6. radiation pattern of microstrip antenna figure 7. is showing circular e-total polarization in 3d view, considering power gain with included reflection. magnitude scale is shown on the left. it can be seen that the polarization is quite good, with reflection well within the acceptable range, since values remand remarkably close to original. figure 7. e-total 3d view of microstrip patch antenna figure 8. represents current distribution diagram of presented antenna design, at 5.16 ghz. it is noted that current has tendency to flow from edges of the antenna to middle parts. this was the exact reason for adding large slot in the middle part. graph proves that mentioned slot, increased current desnsity in area to values greater than 10 a/m. it can be seen that feeding line also, along with bottom right part plays particular role in current distribution, since changes in mentioned area, had lowered the magnitude in right part for consequence. by understanding the current distribution, the antenna design can be further improved to achieve better performance. dss vol. 5, no. 1, 2024, pp. 20-28 27 figure 8. current distribution of the microstrip patch antenna in conclusion the proposed microstrip patch antenna shown in the paper, provides reflection loss of s11=16.71 db, e-φ of 5.333 db and e-θ of -5.18 db. this provides more than sufficient values for the sub 6ghz range. the design and geometrical optimization resulted in operational frequency of 5.16 ghz, with incredible dimensions, especially considering other single element-single port designs. simulation was obtained using abs sweeps, 0 ghz to 6 ghz, respectively. furthermore, the proposed antenna design could be considered as a choice for 5g applications due to its high current density capability and small size. the slot in the middle part of the antenna plays the key role in increasing the current density, while the feeding line and the bottom right part also contribute to the current distribution. on the other hand, future geometrical improvements could be made with usage of optimization algorithms. funding information this research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. declaration of competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. references [1] n. kaur, s. sharma, and j. kaur, “performance comparison 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[21] d. w. boeringer and d. h. werner, “particle swarm optimization versus genetic algorithms for phased array synthesis”, ieee trans. antennas propag., vol. 52, no. 3, pp. 771-779, 2004. microsoft word 26-33_145.docx issn 2744-1741 defense and security studies original research vol. 1, december 2020, pp.26-33 https://doi.org/10.37868/dss.v1.id145 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 26 perspectives and the role of bosnian defense industry in national innovation system benjamin durakovic1, erwin trgo2 1 industrial and mechanical engineering, international university of sarajevo, bosnia and herzegovina 2 mechanical engineering, international university of sarajevo, bosnia and herzegovina *corresponding author: bdurakovic@ius.edu.ba © the author 2020. published by arda. abstract the increased global demand for weapons is growing fast both military and civilian grade equipment. the defense industry is experiencing an increase in its trades and production over the globe. currently global market trade of arms is about us$ 1.9 trillion, with a trend of increase. this paper investigates global trends in defense through analysis of global defense spending and r&d activities with the focus to bosnian defense industry perspectives. it was observed that bosnian defense industry has potential to be one of the key players of the national innovation system through which the national r&d output would make notable positive impact on the national economic performances. keywords: defense industry; r&d investment; innovation; national innovation system 1. introduction over the past decade, the international transfer of weapons has significantly increased with the leaders in the export being the united states, china, russia, france and germany, and the largest importers being india, egypt, saudi arabia, and the united arab emirates (uae) [1]. highly influential companies in the industry when it comes to weapon sales are those from the us and the western europe. in 2016, the combined sales amount from those two areas was usd 194.8 billion. overall, the country with the most influence on overall weapons sale trends is undoubtedly the us [2]. the defense industry is an element for reaching the potential sustainable economic growth of a country. due to the policies a country chooses to pursue, it is decided if and how many resources would be allocated for the defense industry in total [3]. one of the basic concepts of the economics is that producing larger quantities of one commodity would result in producing smaller quantities of another commodity. this means that increased spending in military area would cause lower spending in civilian area. also, economic growth at the local level is impacted by the defense industry as many people depend on the jobs and incomes possibilities created in this industry. defense industry is an essential component in providing security for a country while it eliminates the threat posed by other countries, both in terms of hostility and in terms of imposing their products that would be implemented over the domestic products of a country. moreover, security threats encourage the increase in the development of this industry. in conclusion, defense industry development is the consequence of the overall increase in the country’s total industry production [3][4]. throughout history, the defense industry was seen as a strictly military branch of industry. nowadays it has developed in almost every sphere of our life. the industries operating in this branch have shifted from specialization production to companies which became conglomerates, producing everything for naval, air and land equipment’s and arms. dss vol. 1, december 2020, pp.26-33 27 the goal of this paper to investigate perspectives of bosnian defense industry in national innovation system as well as global trends and local bosnian defense sector opportunities for generating significant added value through customized innovative solution for targeted global market. national innovation system is defined as “…set of distinct institutions which jointly and individually contribute to the development and diffusion of new technologies and which provides the framework within which governments form and implement policies to influence the innovation process. as such it is a system of interconnected institutions to create, store and transfer the knowledge, skills and artefacts which define new technologies” [5]. the defense industry is primarily a business with the main objective to maximize profit with minimal investments. also, bosnian defense industry has all potential to be recognized as one of the strategic industries for the development of the country. 2. top global market trends for the purpose of this research, global trends are reflected in two directions: spending trends and r&d trends. global defense spending continues to increase despite financial pressure due to covid-19. the global defense spending for period 1988 – 2019 is shown in figure 1. figure 1. global defense spending for period 1988 – 20191 the demand for military equipment is growing as governments around the world focus on military modernization busting worldwide defense expenditure. global defense spending reached us$1.914 trillion in 2019, and continue to grow in 2020 for about 3.9% despite coronavirus pandemic. to identify general trends in different weapons deliveries and to permit comparison between the data, stockholm international peace research institute (sipri) developed a unique system to measure the volume of international transfers of major conventional weapons using a common unit, the trend-indicator value (tiv). the tiv trends of total arm transfer for period 1950 – 2019 is presented in figure 2. figure 2. total arms transfers for period 1950 – 2019 2 1 sipri military expenditure database, https://www.sipri.org/gallery/military-spending-graphics-2019 500 700 900 1100 1300 1500 1700 1900 1985 1990 1995 2000 2005 2010 2015 2020 m ili ta ry e xp en di tu re (i n u s$ bi lli on s) year dss vol. 1, december 2020, pp.26-33 28 it is observed that tiv had been growing over the time until it achieved a peak in 1982. in period between 1982 and 2002 the tiv was significantly decreased. since 2002 the tiv has been growing until now. it is expected that covid-19 will slightly slow the tiv growth in upcoming period. the trends in r&d are focused on the artificial intelligence systems, additive manufacturing, as well as cost reduction. future weapons are not something so sci-fi nowadays. electric rifles, advanced magnetic armor, robot soldiers, etc. are all being devised today by big, both public and private institutes [6]. defense is interested in technologies, systems and processes that improve intelligence collection, analysis and dissemination across all capabilities within defense and in all domains: land, maritime and aerospace. this includes the advanced use of biometric data, as well as innovation in cyber technology to support every facet of capability development. supporting the shift from intelligence, surveillance and reconnaissance to targeting, as well as the advancement of hypersonic technology as an opportunity for defense’s space capabilities also warrant attention in this stream. the relevancy of smart defense in modern international security has been on natos list ever since 2008 financial crisis [7]. 2.1. artificial intelligence global market trends are important indicators for the contractors or companies in the global market as the more updated one is the more market area can be covered. according to case studies done [8], the defense industry shifts towards robotics, cyber weaponry and automated complex systems [9]. starting with the main technological trends, artificial intelligence (ai) has certainly become a great tool for defense industry in the sense of processing large amounts of data with which organizations have struggled over the past few years. data processing done by ai allows people to shift their focus on the results and findings in contrast to primarily producing them. advanced robots and augmented reality are some similar paths companies are already taken interests into with heavily investments already being taking places. 2.2. additive manufacturing 3d printing has become a huge disruptor ever since 2017. the militaries are already looking into the potential of printing spare parts and military equipment in-theatre to drive down costs and drive-up availability. the aerospace and defense (a&d) sector is set to become one of the biggest contributors to 3d printing’s global revenues, predicted to reach a mammoth $1.4 billion by 2019, producing parts in-house, a development that will completely reshape the relationship between contractors and manufacturers [10], [11]. 2.3. cost reduction another trend is cost technology. clean technology measures within the a&d sector include energy efficiency, waste management, recycling, use of digital and paperless products, video conferencing, and many more. according to well defined research the budget for the global defense clean technology market will increase 7.5% between 2016 and 2021. this also includes paperless documents and clean power. a difficulty defense companies face as they try to move forward with these environmentally friendly technology initiatives will be integration with current systems. however, the savings over the long run from eco-friendly and costeffective solutions are worth the initial investment. cost-effectiveness can be listed as the back bone of all the major trends. innovation is the key factor in this industry and those who are willing to adapt are those who survive. technology investments are elements that enable manufacturers to innovate on-the-go. these improvements should lower manufacturers’ costs and help them stay a relevant member of the industry. companies in sectors of the healthcare, software and internet show the substantial grow in the r&d spending over the last fifteen years, while typically spend less on r&d and it has been largely flat over recent years. 2 source: sipri trend indicator values (tivs), http://www.sipri.org/databases/armstransfers/sources-andmethods/ dss vol. 1, december 2020, pp.26-33 29 companies from south korea, israel, europe, japan, north america and china demonstrate the most significant growth in r&d spending. figure 3. r&d spending by industry3 3. current state and trend in bosnian defense industry as result of increased global defense spending, in recent years turnover of bosnian defense industry started to grow. reports say that the total income has increased for 21% and the total export has increased for 29% when compared to 2015 [12]. the defense industry is mainly based on the production of ammunition and artillery pieces. this is far away from the time when bosnia as a part of former yugoslavia, produced a wide variety of both complex and non-complex products. being a war-ravaged transition country, the reduction in production is not something out of the ordinary. ukraine, as one of the world’s super power in weapon production, experienced a huge decrease in every branch of their defense industry in their transition period of 1991 to 1999 [13]. through investments in r&d and through arms export to 3rd world countries, ukraine’s defense industry rocketed sky high again. although a small country, with small influence, bosnia can allocate the steps which ukraine undertook in order to get its industry back in its tracks. representative products of bosnian defense industry [14], [15]:  all kinds of small-arms ammunition, ranging from cal. 5.56 to 12.7 mm  artillery howitzers and mortar systems  artillery ammunition, ranging from 75 to 152 mm  mortar ammunition, ranging from 60 to 120 mm  fuses and cartridges  observing and sighting equipment  uniform and soldier protection equipment (military vests, helmets, riot control equipment, boots) recently developed:  self-propelled howitzer 155 mm with fully automatic loading (prototype made) 3 source: capital iq data, strategy and analysis healthcare computing and electronics software and internet auto industries chemical and energy aerospace and defense0 50 100 150 200 250 2005 2007 2009 2011 2013 2015 2017 2019 r& d sp en di ng in u s$ b ill io ns year healthcare computing and electronics software and internet auto industries chemical and energy aerospace and defense dss vol. 1, december 2020, pp.26-33 30  light armored vehicle  gun 9 mm and rifle 7.62 mm  rpg 7 following the world defense industry trends and investing in r&d, bosnia can take a piece of the world trade cake. recently, bosnia developed its first fully automatic, mobile artillery piece. it complies with nato standards, is lighter than its french and serbian competition and is ought to cost less than its counterparts. the manufacturer bnt novi travnik, devised everything except the sophisticated electronics and the truck [14]. analyzing the portfolio of local defense industry, it is observed that only recently developed self-propelled howitzer is on the track with global r&d trends. to be on the track with the global r&d trends in defense, a significant upgrade of the existing product is required, and development of solution for the global market. to asses alignment of bosnian defense sector with the global trends, swot analysis is done and the results are provided in table 1. table 1. swot analysis of bosnian defense industry strengths opportunities tradition in making weapons and other metallurgy products reliable, battle tested products skilled workforce brand growth in global defense spending growing trends in smart weapon ammunition artificial intelligence autonomous complex systems bio design drones laser-based weapons to become strategic industry for bosnian economy weaknesses threats insufficient investment in r&d lack of knowledge needed for the creation of more complex weapon systems little or no r&d lack of political stability current world policies world competitors as previously explained, the strengths are analyzed as one of the internal elements of this analysis. in this case, strengths of the bosnian defense industry are tradition in making weapons and other metallurgy products, reliability of products and proven brands. on the other hand, weaknesses of the industry could either be lack of knowledge regarding producing complex weapon systems, as well as insufficient investment in research and development, which are driving forces of industry growth. tapping into the area of drones, or artificial intelligence based systems could be considered as opportunity of defense industry of bosnia, while the competitors and potential political instability as well as new global policies on defense products and distribution are perceived as threats of the industry. along with the pharmaceutical industry, local defense industry has potential to become one of the key sectors of the bosnian innovation system. innovations are key factors to generate significant added-value, to improve economic performance and to ensure business future. opportunities lie in global defense spending growth, growing trends in smart weapon ammunition, autonomous complex systems, artificial intelligence, drones. spending in defense sector on global level is continuously and significantly grooving, therefore this sector should become one of the strategic industries for the bosnian economy and country development. this is an opportunity to invest in end-user-solutions on the global market through this industry, which will have significant added value and a significant share of knowledge. dss vol. 1, december 2020, pp.26-33 31 comparing the current production program from the bosnian defense industry with global trends, it is observed that significant upgrade is required to keep pace with global trends, which requires significant investment in research and development. therefore, potential investors as well as the government should recognize their interest in this sector, explore and encourage investors to invest. the r&d expenditure for selected countries as percentage of gdp for period 1996 – 2019 is shown in figure 4. figure 4. r&d expenditure in bosnia and for selected countries4 recent spending on r&d projects in bosnia are one of the lowest in the world as well as the lowest in the region. companies and government from bosnia spend less than 0.2% of gdp on r&d projects, which is about 5 times lower than regional average (compared with neighboring countries) and about 15 times less that the average of top global investor in r&d. to improve economic performance of bosnian defense industry, investment in r&d is necessary, since there is significant positive correlation between investment in r&d and economic performance [16]. over the last decade south korea has the highest grow in r&d spending as percentage of gdp. reforms which took place in south korea would be a good model of restructuring the defense industry and the military in general [4]. making strategic alliances with countries that are already producing sorts of smart weapons would be an important step in the development of a domestic smart weapon or ammunition. obtaining the knowledge through partnerships with countries which are leaders in the market, bosnia would be able to become a regional factor in the production of smart weapons. a good example could be the israel, spain and portugal, which became regional leaders in arms production through investments in r&d, but also through their acute strategic need [17]. 4 the world bank, https://data.worldbank.org/indicator/gb.xpd.rsdv.gd.zs bosnia china eu croatia israel japan serbia turkey usa world south korea russia 0 1 2 3 4 5 6 1995 2000 2005 2010 2015 r& d ex pe nd itu re (% o f g d p) year bosnia china eu croatia israel japan serbia turkey usa world south korea russia dss vol. 1, december 2020, pp.26-33 32 as already stated, bosnia’s ammunition products are already used in many nations, all over the world. they are less expensive but battle proven and reliable. so, there is a solid turf at which bosnia can aim their sights. following trends and further developing the production of arms, increases interest in products which are made in bosnia. cooperation between partners countries can definitely lead them to a profound and well-established r&d and manufacturing industry for the defense systems. for instance, in the us most of the r&d investment were made by business, which is shown in figure 5. figure 5. history of r&d expenditure in the us by business and government [18] recently the business share in the us r&d expenditure is about 67% of total gdp for r&d, while the government is about 33% [18]. 4. conclusion opportunities for bosnian defense industry in global trends are analyzed. the defense industry is primarily a business, and as in every business the main objective is to maximize profit with minimal investments. bosnia is a small country and has negligible influence in the global market of arms. this can be considered as an advantage for bosnian defense sector to be specialized on customized solutions for narrow global market rather than modular ones. customized solutions for narrow global market might be less interesting to big players, which could make some room for bosnian defense industry. current rate of expenditure in the r&d sector is not fare below world average, as well as far below regional average. to bridge the gap between the desire to invest in r&d and the provision of the necessary funds, the public private partnership model could be one with an emphasis innovative solution. in order to achieve this, it is necessary to recognize the domestic defense sector as a strategic branch for economic development. opportunities lie in growing of global expenditure for the defense products and positive trend in artificial intelligence systems. tradition in making weapons and other metallurgy products, reliable battle proven products and skilled workforce are major strengths. among the other domestic sectors, the defense industry along with pharmaceutical has the potential to deliver via r&d end user solutions, which qualifies them to generate increased added-value through the knowledge and branding. therefore, the defense industry through the r&d output may play a key role in the national innovation system and achieve notable positive impact on the national economic performances. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. 5. references [1] pieter d. wezeman, dr aude fleurant, alexandra kuimova, dr diego lopes da silva, dr nan tian, and siemon t. wezeman, “trends in international arms transfers, 2019,” 2020. dss vol. 1, december 2020, pp.26-33 33 [2] aude fleurant, sam perlo-freeman, pieter d. wezeman, siemon t. wezeman, and noel kelly, “the sipri top 100 arms-producing and military services companies, 2015,” 2016. 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[online]. available: https://itif.org/publications/2019/08/12/federal-support-rd-continues-its-ignominious-slide. microsoft word 86-95_173.docx issn2744-1741 defense and security studies review article vol. 2, may 2021, pp.86-95 https://doi.org/10.37868/dss.v 2.id173 this work is licensed under a creative commons attribution license(https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 86 review of modern military insensitive high explosives kerim krnjić1 1mechanical engineering faculty, university of sarajevo, bosnia and herzegovina *corresponding author: krnjickerim15@gmail.com © the author 2021. published by arda. abstract in the last twenty years, high energetic materials have changed significantly. several factors have influenced the development of these materials, which include new operational requirements such as insensitive ammunition (im), as well as factors in the availability of new materials and new production techniques, safety assessment, and modeling. all this enables more efficient use of materials and a more detailed understanding of the processes involved in the application of new technologies. this work presents new insensitive secondary high explosives such as tatb, fox-7, gudn, nto, and others that are in different stages of development. a review of these explosives is given and their stability, reliability, and specific application are described. energy materials are known to be chemical compounds or mixtures that contain significant amounts of energy and it has been shown that successful design of new energetic materials with customized performance properties and increased stability is possible. the properties of new insensitive energetic materials must be further researched and improved before they can be used in new or existing systems. insensitive ammunition testing is a vital component of many national im programs. the international community has established requirements for testing the insensitivity of materials and developed six unique tests based on testing the response of the material to the effects of heat, impact, or shock. keywords: insensitive ammunition, fox-7, fox-12, tatb, nto, tests for insensitive ammunition. 1. introduction there are many factors that must be taken into account when assessing newly developed insensitive materials. when developing these materials, it is necessary to harmonize the requirements for high performance and reduced sensitivity, while considering the availability and price of the product. the search for the promising high-energy materials during the last decade has led to the discovery of a vast number of energetic oxidizers, fuels and explosives for their possible use as an energetic ingredient in propellants/explosives formulations. exploitation of structure property relationships, coupled with the use of computer codes to predict the energetic properties from molecular structure, has led to the development of new energetic materials with increased performance, reduced sensitivity to external stimuli and or enhanced chemical and thermal stability. the other important properties which decide the fate of newly synthesized energetic material for its application in propellant and explosive formulations are its chemical compatibility with other ingredients in the formulation, less toxicity, stable physical form and ease of its handling. all these properties are compared dss vol. 2, may 2021, pp.86-95 87 with the properties of known benchmark energetic materials which are currently in use in propellant or explosive formulations. high energy materials research area received less attention from the energetic materials scientists in the past. this may be attributed to the risks and hazards associated with the research investigations. there has been progress in the synthesis and development of new energetic compounds in recent years. the other category of nitro compounds emerging as key ingredients for propellant and explosive formulations are tetrazoles, triazines, tetrazines, compounds of metallic salts of hydrazines, carbohydrazines and polymeric binders containing azo, nitro-, nitroxygroups in the backbones. new requirements such as reduction of the vulnerability of combat platforms, stealth characteristics, and increased demand to achieve higher energetics in terms of specific impulse and performance coupled with environmental issues have forced the researchers to produce novel energetic materials. to develop a new energetic material, it is essential to consider the factors such as indigenous availability of starting materials, ease of its preparation, purity of energetic material and its cost effectiveness. one of the approaches used to synthesize insensitive explosives is basically in the maximum possible percentage of nitrogen in energy materials[1]. a brief overview of certain low-sensitivity energy substances is given. a small number of the presented compounds are already in commercial application, and most are in the research phase. some of the most interesting new energetic materials are: tatb, fox-7, fox-12, tex, nto, rs-rdx, anta, daaf. 1.1. tatb tatb is a secondary high explosive, slightly weaker than rdx but stronger than tnt. it is extremely insensitive to shock, vibration, fire or shock. the possibility of accidental detonation is very small, even under severe conditions, so this explosive can be used for applications that require extreme safety, such as explosives in nuclear weapons where accidental detonation would pose an extreme danger. all british nuclear warheads use tatb-based explosives in their primary phase. some explosive formulations based on hmx, tatb and kel-f were characterized for density, vod (velocity of detonation), initiation sensitivity, ignition temperature and other explosive properties. at a density of 1.80 g/cm3, the tatb has a detonation velocity of 7350 m/s. it decomposes without melting at 350 °c, and is stable at temperatures up to 250 °c even over a long period of time. pure tatb has a light yellow color and is insoluble in most solvents [2]. 1.2. fox-7 fox-7 or dadne is a candidate for use as an insensitive explosive. this molecule has attracted attention due to its insensitivity to external impulses and its performance comparable to rdx and hmx, while its sensitivity to shock and friction is much lower than that of rdx and other nitramines. there are three different pathways of fox-7 synthesis beeing developed, all involving nitration of the heterocyclic compound followed by hydrolysis to give fox-7. nitration is performed with mixed acid (sulfuric or nitric acid) at low temperature (<30 °c), and hydrolysis can be performed by isolating the intermediate and hydrolyzing with aqueous ammonia or by adding an acidic mixture of the nitrated intermediate with water [2]. some properties of fox-7 compared to the properties of rdx are given further in table 1. table 1.shows that the fox-7 is much less sensitive to shock and shock than the rdx, and is very insensitive to friction. the detonation properties are comparable to rdx. because of all of the above, the fox-7 can be considered an attractive alternative to the rdx. table 1. properties of fox-7 (calculations with cheetah 1.40) and comparison with rdx [2] property fox-7 rdx bam impact sensitivity (nm) >15 7.4 petri friction sensitivity (n) >200 120 deflagration temperature (oc) >240 230 density (g/cm3) 1.885 1.816 formation energy (calculated)(kj/mol) -118.9 92.6 detonation velocity (calculated)(m/s) 9040 8930 detonation pressure (gpa) 36.04 35.64 dss vol. 2, may 2021, pp.86-95 88 1.3. fox-12 (gudn) energy dinitramides are high-energy materials that can be used for the purposes of synthesizing lowsensitivity ammunition. n-guanylurea dinitramide (gudn or fox-12) is a stable salt of dinitramidic acid that has good thermal stability and low solubility in water, has good resistance to mechanical shocks and as such is used in the application of insensitive energy materials [3]. its thermal stability is comparable to rdx and superior to ammonium dinitramide (adn). fox 12 can be used for casting as with lova (low vulnerable ammunition) fuels. in addition to the advantages of low sensitivity fox-12 burns at low temperatures, important in automatic rifles due to the erosion of barrels. the effect of fox-12 was assessed by thermochemical calculations. these calculations were based on density (ρ = 1.7545 g /cm3) and heat of formation (δhf = -355.64 kj/mol) . the results are shown in table 2. the density, detonation velocity, and detonation pressure for fox 12 are between the density values of tnt and rdx. replacing rdx with fox 12 in the rdx / tnt 60/40 composition causes a decrease in density and a consequent decrease in detonation velocity and pressure [3]. table 2. calculated characteristics [4] explosive density (g/cm3) detonation velocity (m/s) detonation pressure (gpa) fox-12 1.75 8210 25.7 tnt 1.65 6900 19.6 rdx 1.81 8940 34.7 fox-12/tnt (60/40) 1.61 7650 23.3 rdx/tnt (60/40) 1.74 8050 28.1 1.4. tex tex is a derivative of the powerful and very sensitive cl-20 explosive. unlike the cl-20, the tex is insensitive to friction, has low impact sensitivity and has a low impact sensitivity and a large critical diameter, which makes it an interesting explosive charge for insensitive ammunition. tex has a crystal density of 1.99 g/cm3, the highest density of all nitramine explosives. the high density is due to its isovurtzitan structure, which has a tightly packed crystal lattice, and nitro groups occupy the free space between the cages. tex is a very energetic material (due to the tense structure of the cage) that has a good combination of high detonation velocity with low sensitivity to mechanical stimuli and good thermal stability. the insensitive nature of tex suggests that it could be a suitable alternative to tatb, nto and rdx high performance explosives [5]. 1.5. nto nto is an insensitive highly explosive material, a potential substitute for rdx in explosive formulations. although its performance is slightly lower than that of rdx, nto is more thermally stable and less sensitive to external influences. nto has performance levels close to rdx levels and its insensitivity is comparable to tatb. its thermal stability is also high and it decomposes exothermically to about 272 °c. the pressure in nto and cast explosives show superior mechanical and thermal properties and are insensitive [6]. 1.6. rss-rdx rdx is sensitive to mechanical stimuli such as shock and friction. in recent years, it has been dedicated to the development of rdx in another form, with reduced shock sensitivity rdx (rss-rdx) or insensitive rdx (insensitive rdx or i-rdx). when this explosive is incorporated into a molded polymer explosive pbx-109, it can reduce impact sensitivity [7]. it is important to note that i-rdx and conventional rdx do not differ in chemical, physical, and safety characteristics, and even raw impact sensitivity tests. i-rdx and conventional rdx can be produced in the same particle size distribution ranges. differences between i-rdx and dss vol. 2, may 2021, pp.86-95 89 conventional rdx are visible in the impact sensitivity characteristics of cast pbx compositions. it was also observed that the use of i-rdx does not change any properties of pbx (such as aging, reaction to thermal stimuli, etc.), but only the properties of sensitivity to shock [8]. 1.7. anta and daaf anta is an amino-nitro-heterocyclic compound used in the use of im due to the high heat of formation. it can also be said that the insensitive energy material with a density of 1.81 g/cm3, 228 °c melting point, 225.2 kj/mol heat of formation and performance is slightly lower than tatb [6]. daaf is also an insensitive explosive that has good resistance to mechanical stimuli and characteristics similar to those of tatb. with its characteristics such as density 1.747 g/cm3, heat of formation 443.5 kj/mol, impact sensitivity h50%>320 makes it suitable for use in boosters [9]. 2. technical requirements for im (insensitive munitions) in fact, the potential to develop energetic materials with im properties is not limited to new materials. the sensitivity of well-established energetic materials can be reduced through various material improvements, such as better crystal quality, reducing crystal or molecular defects, eliminating voids, chemical impurities or the existence of multiple phases. properties that are advantageous for im systems include the following [10]: high decomposition temperature; low impact and friction sensitivity; no phase transitions when the substance is subjected to rapid volume expansion or contraction; no autocatalytic decomposition; spherical crystal morphology; good adhesion of the binder matrix; no voids brought about by solvent or gas bubbles; phase purity. performance characteristics and im properties of various materials are given in table 3. table 3. performance characteristics of explosive components and example formulations [11] properties rs-rdx fox-7 gudn nto tex daaf tatb decomposition temperature (oc) 238,8 260 217 272 >250 249 >350 melting point (oc) 206 254 no 270 299 255 330 oxygen balance (%) -21.6 -21.6 -19.1 -24.6 -42.7 -22.64 -55.8 detonation pressure (gpa) 34.1 33.7 25.7 349 365 306 300 velocity of detonation (m/s) 8750 9090 8210 8500 8560 7930 8100 impact senisivity (cm) 39 126 >49 87 170 >320 170 friction sensivity (n) 160 360 >335 360 490 >360 >360 ∆hf-heat of formation (kj/mol) 16 -133.9 -355 -129.4 -445.6 +443.35 -140 density (g/cm3) 1.82 1.87 1.75 1.93 1.99 1.74 1.93 3. tests and standards for insensitive ammunition the primary purpose of im testing is to determine the response of ammunition to unplanned stimuli when tested under certain conditions. this information is then used to determine compliance with national im policies. system security testing conducted 50 years ago in the united states has become the foundation of today’s im testing standards. in 1964, the us navy established a safety directive for the wr-50 system for registering warhead vulnerabilities and certain security features [12]. this included a fast and slow cook-off test and a reaction to a projectile impact. following the establishment of the im program in the united states, requirements for im tests were also introduced. requests for testing also followed in the international community through the nato program. nato established im principles and technical requirements in 1995, and in 2003 the usa incorporated nato technical requirements into mil-std-2105c [13]. the test requirements are defined via individual stanags. the number of tests and testing practices varies from country to country, but most im testing programs are based on nato stanag 4439 edition 2 (policy for introduction and assessment of insensitive ammunition (im)) and aop-39 (guidance on the assessment and development of insensitive munitions (im)) edition 2 [14]. for each of the six tests defined in aop-39, there dss vol. 2, may 2021, pp.86-95 90 is a standard test designed to classify ammunition based on the type of response. those six tests and their performance are [15] : 1. slow cook-off – this requirement specifies a slow warming test that may result from a fire in an adjacent magazine, premises, or vehicle. these types of incidents require exposure to a gradually increasing thermal environment at a rate of 3.3 °c/h. 2. fast cook-off – the requirement to investigate the danger of rapid warming comes from a liquid fuel fire, such as burning aviation fuel on a flight deck or burning diesel fuel from a truck as a result of a car accident. therefore, these types of incidents require the test sample to be exposed to heat fluxes in a burning flame of a burning fuel. 3. sympathetic detonation − the purpose of this test is to subject one or more packages of ammunition to the effects of the worst case scenario, is to detonate an identical package of ammunition under conditions that are most likely to result in a sympathetic reaction. the purpose is to determine the sympathetic response of ammunition sensitivity and ultimately to provide information on the effectiveness of the safety barriers used to separate a single, packaged, or multiple ammunition package. 4. multiple bullet impact − this requirement describes the examination of the danger of ammunition strikes from small arms during terrorist or combat events. the aim of this test is to provide a standard test procedure for assessing the reaction of ammunition to the impact of a triple burst of m2 machine gun, caliber 12.7 mm, ap ammunition (armor-piercing). 5. multiple fragment impact – the request for testing comes from combat or terrorist events that use artillery missiles or improvised explosive devices for attacks. to predict the response of ammunition to these types of events, the test sample is subjected to the impact of a calibrated high-speed fragment representing fragments of a bomb or fragments formed from artillery grenades. 6. shaped charge jet impact testing − this test is performed due to possible damage or unwanted reaction of ammunition when using missiles, guided weapons or air bombs. the test is performed by subjecting the ammunition to a direct impact of a cumulative shaped charge jet and monitoring their reaction. it is also preferred that the diameter of the detonation be larger than the diameter of the jet so that the test can be performed. 4. chemical and thermal stability of im 4.1. chemical stability an energetic material may undergo chemical reaction in response to shock, thermal, or chemical insults. in this review, we concentrate on stability to shock excitation. it is often the case, however, that a material’s stability to various forms of loading is highly correlated with one another. energetic materials exist in a higher energy state than their lowest energy decomposition products. thus energetic molecules are often termed metastable. recently, several metastable nitrogen and oxygen compounds have been proposed that contain novel bonding. this has led to recent theoretical studies of hypothetical systems as high-energy density materials (hedm), such as oxygen ring–strained systems (o4 and o8), tetrahedral n4, and cubic n8. the dissociation energy of the weakest bond of an explosive molecule plays an important role in initiation events. however, the correlation between bond strength and impact sensitivity is not general, but is limited within a particular class of molecules. given the complexity of the chemistry of detonation of explosives, it is not surprising that the energy of dissociation of bonds alone is not sufficient to explain the sensitivity of explosives [16]. it can be seen from table 3. that there is some correlation between the dissociation energy of the de bond and the sensitivity of the explosives. nitrobenzene compounds with the highest de values are the least sensitive. the correlation between de and ed could be an important quantity in determining the impact sensitivity of molecules[16]. dss vol. 2, may 2021, pp.86-95 91 table 3. bond strength (de) of the weakest bond, energy content (ed, kj/cc), impact sensitivity h50 (cm) [16] material weakest bond de (kj/mol) ed (kj) h50 (cm) tatb c-no2 323 8.6 >320 datb c-no2 312 8.6 >320 tna c-no2 300 8.1 177 tnt c-no2 261 7.7 148 hmx n-no2 179 11.1 32 rdx n-no2 174 10.4 28 tnaz c-no2 167 11.229 29 nto c-no2 284 7.7 >280 tetryl c-no2 120 8.8 37 tnb c-no2 283 8.6 100 edna n-no2 207 9.2 35 hnb c-no2 183 14.3 8,5 dingu n-no2 180 8.5 24 petn o-no2 167 10.5 14 n n-no2 157 10.0 20 from an analysis of the structures of thermally stable explosives, it appears that there are four general approaches to impart thermal stability to explosive molecules [17]:  introduction of amino groups;  condensation with a triazole ring;  salt formation;  introduction of conjugation. 5. detonation performance analyses for recent energetic molecules in order to assess the potential of new high-energy materials, their energy characteristics must be compared with those of modern materials. one of the programs used to predict im performance is jaguar's computer program, which provides accurate estimates for the detonation and performance of an explosive if precise data on its density and heat of formation are known. this post-assessment data is used to compare performance against already known energy materials such as tnt, rdx, hmx and cl-20. the detonation properties of the known compounds obtained by the jaguar model have deviations of about 2-3% compared to the experimental results. the predicted values of the c-j velocities, temperatures, and pressures, gurney velocities at 3 and 7 area expansions, and limiting energies are presented in table 4.[18]. table 4. jaguar predicted detonation properties [18] explosive density (g/cm3) ∆hf (kj/mol) det. velocity (km/s) c-j pressure (gpa) c-j temp. (k) gurney velocity (km/s) boundary energy e0 (kj/cm3) oxygen balance (%) cl-20 2.044 376.6 9.79 45.6 4035 2.88 -13.07 -11 tnaz 1.832 11.8 8.73 35.1 4224 2.77 -11.49 16.7 hmx 1.905 75 9.09 38.7 3514 2.76 -11.38 -21.6 rdx 1.816 70 8.76 34.8 3708 2.73 -10.88 -21.6 tnt 1.654 -63 6.89 19.8 3092 2.20 -7.11 -74 tatb 1.937 -140 8.778 31.8 2393 2.12 -7.78 -55.6 fox-7 1.885 -133.9 8.80 35 2917 2.554 -9.35 -21.6 tex 1.99 -445.6 8.51 32.7 2631 2.26 -8.83 -40.4 daaf 1.747 443.35 8.16 28.2 3155 2.44 -8.23 -52.8 nto 1.93 -129.4 8.64 32.7 2389 2.25 -7.34 -24.6 dss vol. 2, may 2021, pp.86-95 92 5.1. c-j and gurney velocity comparisions for energetic compounds the results obtained by the jaguar model from table 4. require some accuracy checking in the form of a comparison of the experimental detonation and the gurney velocity with the values obtained from the jaguar model and the analytical model of the cylinder. table 5 shows a slight deviation in the results. nto and daaf values and their formulation with hmx, rdx, viton were taken for experimental velocities [18]. table 5. nto and daaf formulations [18] explosive wt (%) density (g/cm3) dexp (km/s) djaguar (km/s) nto 100 1.87 8.22 8.38 1.86 8.20 8.31 1.83 8.09 8.18 1.80 8.02 8.07 daaf 100 1.685 7.93 7.93 daaf/rdx/viton 80/15/5 1.66 7.76 7.70 daaf/nto/viton 60/35/5 1.67 7.91 7.83 for the initial density of the fox-7/viton (95/5) mixture, the obtained gurney velocities with the jaguar and the analytical model of the cylinder show a very small deviation from the experimental values, the illustration of which is given in figure 1. [18]. figure 1. gurney velocity change for fox-7 / viton explosive at a density of 1.945 g/cm3 [18] figure 2 shows a very small deviation of the calculated gureny speed with jaguar and the analytical model of the cylinder from the experimental values for the mixture of dnmt/hmx formulation (49.5/50.5) at an initial density of 1.725 g/cm3 [18]. the analyses provide insight into the detonation behavior and performance of the new available high-energy low-sensitivity explosives. jaguar has proven to be a method that is consistent with experimentally derived results for most high-energy materials. dss vol. 2, may 2021, pp.86-95 93 figure 2. gurney velocity change for dnmt/hmx explosives at a density of 1.725 g/cm3 [18] 5.2. predicting detonation velocity using cheetah 1.40 predicting the density and heat of formation can provide insight into the possible performance of high-energy materials. the results of a study of one such prediction are shown in figure 3. [19]. the calculated detonation velocities of several explosives are presented using two different ways of using the cheetah 1.40 program, namely the thermochemical code and using the bkwc library (backer-kistiakowski) wilson/cheetah at full crystal density [20]:  the first set of data, the calculated detonation velocity was based on the experimental heat of formation and density.  second set of data, the calculated detonation velocity was based on the theoretically predicted heat of formation and density. figure 3. detonation velocities predicted by cheetah 1.40 [20] dss vol. 2, may 2021, pp.86-95 94 6. conclusions no explosive molecule has all the desired properties from a high efficiency and low sensitivity perspective. in a constant effort to optimize desirable properties such as insensitivity to stimuli and shocks (shock, spark and friction), as well as high thermal stability and small critical diameter, various energy materials and material mixtures are constantly researched and developed. the main disadvantages of current conventional explosives such as those based on rdx and hmx are the relatively high impact sensitivity and moderately high handling sensitivity. however, their advantage is small critical diameter and high performance. with materials that are the basis of low-sensitivity ammunition, there is a compromise for lower performance and higher critical diameter, but impact sensitivity is reduced and sensitivity in handling is almost eliminated. insensitive ammunition (im) is defined as ammunition that reliably meets its performance, readiness and operational requirements when needed, but minimizes violent reactions and subsequent collateral damage when exposed to unplanned stimuli. testing is a vital component of any national im program. hazards and threats to high-energy materials are either thermal events or caused by shock and shock. the international community has established requirements for testing and testing the insensitivity of materials, developing six unique tests representing these events. there are two basic documents that provide guidelines for im testing. stanag 4439 (nonsensitive ammunition introduction and assessment policy), lists all stanag tests that provide requirements and provide guidance for individual im tests. additional information can be found in aop-39 (guidelines for the assessment and development of non-sensitive ammunition). this document includes test requirements, test protocols, a list of response descriptions, and an assessment methodology for im coding. thermochemical calculation methods have been developed to predict the properties of new materials. the detonation properties of the known compounds can be calculated with deviations of about 2-3% from the experimental results. in the future, it is expected that a wider range of energy materials will be able to be adapted to specific purposes. many new low-sensitivity energy materials are still in the experimental phase. their production costs are very high, which is currently a limiting factor for their use. therefore, it is necessary to make an effort to make their production profitable. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] r. meyer, j. kohler, explosives, 4th revised and extended ed., vch publishers, weinheim, new york, 1993. [2] dilip m. badgujar, mahadev b. talawar, pramod p. mahulikar, high energy materials research laboratory, pune-411021, india 2 school of chemical sciences, north maharashtra university, jalgaon-425001, india. [3] h.östmark, u.bemm, h.bergman,a.langlet, “n-guanylurea-dinitramide: a new energetic material with low sensitivity for propellants and explosives applications”, termochimica acta, 384, 253-259, 2002. [4] h.oestmark, a.helte, t. carlsson, “n-guanylurea-dinitramide (fox-12): a new extremely insensitive energetic material for explosive application”. proceedings of the 13th international detonation symposium, 121-127, 2007. dss vol. 2, may 2021, pp.86-95 95 [5] e. koch, “tex-4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo dodecane review of a promising high density insensitive energetic material”. propellants, explosives, pyrotechnics, 40 (3): 374–387, 2015. [6] j. p. agrawalt, physics and chemistry of solids, cavendish laboratory, university of cambridge, cambridge. u.k. [7] p.f. pagoria, a.r. mitchell, r.d. schmidt, r.l. simpson, f. garcia, j. forbes, j. cutting, r. lee, r. swansiger, d.m. hoffman, presented at the insensitive munitions and energetic materials technology symposium, san diego, ca, 1998. [8] a.freche, j.aviles, l. donnio, c.spyckerelle, insensitive rdx (irdx), insensitive munitions and energetic materials symposium technology implementation in the 21st century, san antonio, texas, 2000. [9] t.han, p.pagoria, a.gash, a.maiti, c.orme, a.mitchell, l. fried, “the solubility and recrystallization of 1,3,5-triamino-2,4,6-trinitrobenzene in a 3-ethyl-1-methylimidazolium acetate-dmso co-solvent system”. new j. chem., 33, 50, 2009. [10] h.r.bircher, p. mäder, j. mathieu, “properties of cl-20 based high explosives”, in: proc. 29th int. annual conference of ict, karlsruhe, 94, 1994. [11] a.pillai, m.joshi, a.barve, s.velapure, j.karir, “cellulose acetate binderbased lova gun propellant for tank guns”. def. sci. j., 49(2): 141-149., 1995. [12] r. beauregard, ”history of the us navy’s im program”, january 2005. [13] mil-std-2105c: hazard assessment tests for non-nuclear munitions, july 2003. [14] stanag 4439, edition x, “policy for introduction and assessment of insensitive munitions”, november 2018. aop-39, edition 3, “guidance on the assessment and development of insensitive munitions”,march 2010. [15] afanosev, c.; bobolev, u. “initiation of solid explosives by impact”. israel program of scientific translations, jerusalem 1971. [16] l. e. fried, m. r. manaa, p. f. pagoria, r. l. simpson energetic materials center, chemistry and materials science directorate, lawrence livermore national laboratory, p. o. box 808, livermore, california 94551. [17] j. p. agrawalt, physics and chemistry of solids, cavendish laboratory, university of cambridge, cambridge. u.k. [18] https://doi.org/10.1063/1.5044989 [19] l. e.fried, m. r.manaa, p. f.pagora, r. l.simpson, “design and synthesis of energetic materials”. annu rev mater res., 31, 291-321, 2001 [20] l. e. fried, p. c. souers, “bkwc: an empirical bkw parametrization based on cylinder test data”, propellants, explosives, pyrotechnics, 21,215–23, 1996. microsoft word 67-73_202 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.67-73 https://doi.org/10.37868/dss.v3.id202 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 67 (16pt) (16pt) increasing cultural intelligence for military troops and civilian officers serving in the united nations organization stabilization mission in the democratic republic of the congo (monusco) (16 pt) furqan abdul rais zordi1*, siswo hadi sumantri2, m. adnan madjid3 1,2,3 indonesia defense university, indonesia (9 pt) (9 pt) *corresponding author e-mail: furqan.abdul.r.z@gmail.com received: oct. 23, 2022. revised: nov. 1, 2022 accepted: nov. 2, 2022 online: nov. 6, 2022 abstract the democratic republic of the congo is still experiencing internal political turmoil between the tutsi and hutu tribes. therefore, the united nations through the security council established the united nations organization stabilization mission in the democratic republic of the congo (monusco) to monitor the peace process after the second congo war. several approaches must be applied so that the mission carried out is able to reconcile the conflicting actors. the purpose of this research is to find out the obstacles faced in the monusco mission and their solutions. the method used in this research is to use a literature study and to test the credibility of the data found. the peace mission carried out by monusco can be said to be quite successful despite facing several strategic and operational challenges. the use of cultural intelligence and prospect theory in pre-mission training should be done in order to increase the success of the mission. © the author 2022. published by arda. keywords: peacekeeping, cultural intelligence, prospect theory, monusco, democratic republic of the congo 1. introduction the congo conflict was caused by the protracted conflict in the democratic republic of the congo. before the conflict occurred, there were two wars that caused further conflict, namely the first congo war (africa's first world war) and the second congo war (great war of africa). this war was a civil war as well as an international military conflict that took place in the democratic republic of the congo, formerly known as zaire. the beginning of the conflict was caused by a severe economic downturn in 1996 and longstanding inter-tribal disputes under president mobutu sese who was a dictator [1]. in addition, the unstable conditions on the eastern border which were affected by the rwandan genocide also contributed to the escalation of conflicts that occurred in the country. president mobutu sese's deteriorating health condition also caused the government's authority to almost collapse. this put the militias, rebels, and soldiers at odds with each other [2]. ethnic tensions have existed for generations in zaire, especially in the east. these tensions occurred mainly between the indigenous agrarian tribe of zaire, the hutu and the tutsi who settled semi-nomadic and had emigrated from rwanda. the tutsis who emigrated to zaire before congo's independence in 1960 are known dss vol. 3, 2022, pp.67-73 68 as banyamulenge and have citizenship rights under zairian law. while the tutsis who emigrated to zaire after 1960 are called banyarwanda, although the natives often do not distinguish these differences, they still refer to banyamulenge and banyarwanda as foreigners [3]. banyamulenge launched a rebellion aimed at seizing power in the province of kivu in the eastern part of the country of zaire. the rebellion was an anticipatory measure to combat hutu extremist forces who were trying to continue the genocide in zaire. president mobutu sese's harsh policies in dealing with rebellions made him a common enemy at all levels of society. as a result, the new uprising gained massive public support and grew into a general revolution and not just an uprising promoted by banyamulenge. the rebellious militias belonged to the alliance of democratic forces for the liberation of congo (afdl) [4]. the culmination of this war was the occupation of the capital city of kinshasa by the afdl assisted by foreign militaries from uganda, rwanda, and eritrea and the overthrow of president mobutu sese. furthermore, the power was held by the leader of the afdl, namely laurent-désiré kabila. he later changed the name zaire to the democratic republic of congo [2]. the democratic republic of the congo led by kabila shows the similarity in the method of government, this is evident where the social and economic conditions in the country have a higher and more severe level of corruption compared to the era of president mobutu sese's leadership. the economy remained in a state of disrepair and worsened under the kabila government. on the other hand, kabila started an intense campaign of centralization of government that gave rise to new conflicts with minority groups in the eastern part of the democratic republic of the congo who demanded special autonomy [5]. president kabila's leadership is also seen as a “puppet” of foreign governments. in order to dispel this image, he began to fight against his allies from abroad during the first congo war. the culmination of this event was the expulsion of all foreign troops from the democratic republic of the congo on 26 july 1998 [6]. this incident had an impact on the internal political conditions in the country. on august 2, 1998, banyamulenge in goma formed a rebel group called rally for congolese democracy (rcd) and fought against president kabila. rcd itself is also supported by rwanda and uganda [7]. on the other hand, the government of president kabila was supported by namibia, zimbabwe, angola, chan, libya and sudan [8]. in 2001, president kabula was shot and killed by rashide mizele who was his personal bodyguard. in order to fill power, joseph kabila was appointed president by the congo parliament replacing his father [9] [9]. this war ended with a peace agreement between the democratic republic of the congo and rwanda on july 30, 2002 in the pretoria accord [10] and between the democratic republic of the congo and uganda on september 6, 2002 in the luanda agreement [11]. although it has entered a period of peace with its neighbors, the democratic republic of the congo is still experiencing internal political turmoil between the tutsi and hutu tribes. therefore, the united nations through the security council established the united nations organization stabilization mission in the democratic republic of the congo (monusco) to monitor the peace process after the second congo war. in order to increase the success of the peacekeeping mission carried out by monusco in the democratic republic of the congo, several approaches must be applied so that the mission carried out is able to reconcile the conflicting actors. therefore, the authors recommend training and coaching regarding the application of cultural intelligence and prospect theory to peacekeepers serving in the democratic republic of the congo. 2. research method this study uses a documentation study which is defined as a data collection technique by studying documents to obtain data or information related to the problem under study [12]. the data collection technique is done by means of literature study. literature study is a study carried out using literature (library), either in the form of books, notes, or reports on research results from previous researchers [13]. collecting data through library research is done by looking for sources from textbooks, articles, journals, electronic media, magazines and other related sources. credibility testing is carried out by extending observations, increasing persistence, triangulation, negative case analysis, using reference materials, and member checks in order to obtain the dss vol. 3, 2022, pp.67-73 69 degree of accuracy of the research design with the results to be achieved [12]. in addition, this study also uses several theories, which are described below: 2.1. cultural intellegence cultural intelligence is defined as a person's ability to function effectively and in diverse cultural conditions. cultural intelligence is a multidimensional construct that is intended to be used in situations where crosscultural interactions are required due to differences in race, ethnicity, and nationality [14]. cultural intelligence is also a personality that can be developed (state-like personality) and not a personality that is stable and cannot be changed (trait-like personality). in order to measure a person's cultural intelligence, several measurements are needed based on four indicators, namely [15]:  metacognitive intelligence (metacognitive cq) metacognitive cq shows a person's mental processes in obtaining and understanding cultural knowledge, including knowledge about control over individual thinking processes related to culture [16]. skills related to metacognitive intelligence are the ability to plan, monitor, and revise mental models of personal cultural norms in order to adapt to a country or group of people. individuals who have high metacognitive intelligence are instinctively aware of the cultural preferences of others before and during interacting with them. individuals who have high metacognitive intelligence also question the cultural assumptions of a region and adapt them to their mental models during and after interactions [17].  cognitive intelligence (cognitive cq) cognitive intelligence shows a person's knowledge of norms, practices, and conventions in different cultures and is obtained from education and personal experience. individuals who have high cognitive intelligence are able to understand the similarities and differences across cultures [17].  motivational intelligence (motivational cq) motivational intelligence is the ability to direct attention and personal energy to learn and contribute in conditions that are rich in cultural differences. individuals who have high motivational intelligence are able to direct their attention and personal energy to cross-cultural conditions based on intrinsic interest [18] and belief in their cross-cultural effectiveness [19].  behavioral intelligence (behavioural cq) behavioral intelligence is intelligence that shows a person's ability to show appropriate verbal and nonverbal actions when interacting with people from different cultures. individuals with high behavioral intelligence are able to show behavior that is in accordance with conditions based on their verbal and nonverbal abilities [20]. 2.2. prospect theory prospect theory is a psychological theory that describes how a person's actions in assessing their advantages and disadvantages in an asymmetrical condition [21]. prospect theory begins with the concept of loss aversion which is an asymmetric form of risk aversion. the results of research observations show that people will react differently when faced with potential losses and potential gains. this is based on certain situations when potential losses and potential gains are faced by them. the act of selecting the existing potential is called reference dependence which can be explained as follows: (1) when a person is faced with a risky choice that leads to a potential profit, they tend to avoid risk by choosing an option that has a smaller return but has a higher level of certainty of profit. tall; (2) if faced with risky choices that lead to potential losses, they tend to take risks by preferring options that have lower returns as long as those choices have the potential to avoid losses. 3. results and discussion 3.1. obstacles in the monusco mission the united nations organization stabilization mission in the democratic republic of the congo (monusco) is a united nations peacekeeping force in the democratic republic of the congo (drc) dss vol. 3, 2022, pp.67-73 70 created by the united nations security council in resolutions 1279 (1999) and 1291 (2000) to monitor the second congo war peace process. however, the focus of the mission being carried out shifted to dealing with the ituri conflict, the kivu conflict and the dongo conflict. prior to the issuance of un security council resolution (unscr) 1291, unscr resolution 1258 (1999) was issued with the initial aim of being a military observer in the democratic republic of the congo to observe and report on the compliance of factions in reaching a peace agreement [22]. at this time, unscr resolution 2612 (2021) is the basis used by the united nations to authorize monusco to carry out peace missions in the area [23]. at the start of implementing the measures to end the mission in the drc, it is very important to carry out an impact assessment of the monusco activities. in carrying out such impact assessments, observers may have to change the point of view used in assessing un peacekeeping actions. it should also be acknowledged that peacekeeping missions are only provided with funding sources in locations that do not have high priority and have limited strategic importance. most missions have accomplished much and assisted the international community in monitoring and preventing conflicts from escalating to massive levels of violence. given the relatively few resources allocated to large areas, the achievements of monusco have been impressive. peacekeeping missions do their best to carry out mandates that are often unrealistic or overly ambitious, and measuring their effectiveness should also involve examining the reality of implementing the mandates presented by the security council against the means and capabilities at hand [24]. some of the strategic impacts of the ppb peacekeeping mission in the drc can be traced from the mission carried out by the united nations mission in the democratic republic of congo (monuc), which was the predecessor to monusco. one of them is the success of the mission in the reunification of the country. which if the peacekeeping mission is not carried out properly, it is likely that the drc will not exist in its current form. in addition, monuc/monusco also has a strategic impact in preventing the recurrence of major violent conflicts by using its presence to enable international, national and private sector actors to provide services to the community as well as to stimulate local economies and support democratic politics. the role of monuc/monusco is also very important in monitoring, reporting, collecting and sharing information related to human rights violations in support of international criminal justice and the fight against impunity [24]. on the other hand, the mission carried out by monusco encountered several strategic obstacles, namely: (1) the decreasing level of cooperation between the un forces and the drc; (2) the role of neighboring countries in triggering instability; and (3) the absence of a winner for monuc and monusco on the security council to utilize a mutually agreed blueprint for comprehensively addressing conflict. the mission also faced a number of operational obstacles, namely (1): operational and tactical challenges due to not having adequate facilities and capacity to carry out the mission; (2) the contingent of peacekeepers who do not want to carry out the mandate given; (3) lack of effective leadership and pre-mission training; (4) the problem of multiple interpretations of what peacekeeping and mission mandates are; (5) lack of strategic communication strategies to reduce misunderstandings and to explain the mandate and mission to the drc community or even internally [24]. the rejection of the monusco mission was also voiced by the local community, for almost 25 years, the united nations has continued to renew the mandate of the monusco mission in drc, but from year to year the situation is getting worse [25]. anti-un protests have occurred in recent years. however, the demonstrations that took place in august 2022 were large-scale demonstrations. peacekeepers shoot dead civilians. the demonstration that took place claimed 36 lives, four of whom were peacekeepers. the demonstrations come amid an insurgency by the m23 armed group that has seized swathes of territory in the eastern province of north kivu. protesters say monusco has been slow and has failed to acknowledge rwanda's alleged support for the group. most residents in north kivu province and ituri province want the 12,000 monusco peacekeepers to leave the drc immediately [26]. monusco came to protect the people dss vol. 3, 2022, pp.67-73 71 of drc, but there was only a feeling of insecurity. therefore, monusco has failed in its main mission to protect civilians [27]. 3.2. applications of cultural intelligence and prospect theory in peacekeeping the use of cultural intelligence in peacekeeping is able to provide a framework for improvement of the design and implementation of cross-cultural activities. in addition, the end of the cold war forced modern military forces to be able to carry out peacekeeping operations as part of a coalition of international cooperation. it is also possible that the commando team on the ground consists of troops with diverse cultural backgrounds. therefore, the application of cultural intelligence is very important to be applied to peacekeepers in order to prepare cross-cultural leadership competencies. several ways that can be done to improve cross-cultural leadership competence can be described below [28].  modified cognitive behavioral techniques (personal reflection, planning and monitoring skills) can be used to train metacognitive intelligence.  training on traditional cultural awareness (specific knowledge about the destination country) can be used to increase cognitive intelligence.  goal setting and goal setting techniques can be used to increase motivational intelligence  dramaturgy approach by way of role playing, performance, and visual arts can be used to train and improve behavioral intelligence. an example of the use of cultural intelligence and prospect theory can be seen in the success of the garuda xii contingent that is part of the u.n. transitional authority in cambodia (untac) in cambodia. the program run by the garuda contingent emphasizes building a common identity and minimizing differences between local residents. the openness of the indonesian military camp to the local population made it easier for the garuda contingent to mingle and discuss with local residents from all walks of life. in addition, the similarity of skin color and high patience greatly benefit them in approaching groups that are quite difficult to approach. the garuda contingent always invites and includes local residents in the activities of indonesian holidays, traditions and customs at the military camp. the garuda contingent's programs such as health and dental care, video broadcasts, sports activities, and village development projects where planning and implementation always involve local communities further increase their trust in the garuda contingent. the local communities who were involved in the garuda contingent's activities were both supporters and members of the conflicting actors. this made the garuda contingent able to carry out development programs in all areas including areas controlled by the khmer rouge where this situation could not be achieved by other peacekeepers serving in cambodia [29]. the actions of the garuda contingent that benefited all parties made the conflicting actors prefer to make peace with common interests. this is in accordance with the determination of reference dependence point 1 where when a person is faced with a risky choice that leads to potential benefits, they tend to avoid risk by choosing the option that has a smaller return but has a higher level of certainty of profit [21]. 4. conclusions although there are differences in social, political and economic conditions between cambodia and the democratic republic of the congo, there are similarities in conflict between the two countries where the conflicting actors have different cultural backgrounds. by placing troops that have high cultural intelligence, the garuda xii contingent is able to increase the percentage of program success that is higher than peacekeepers from other countries. in addition, by giving benefits to all warring parties, the warring actors in the conflict in cambodia decided to make peace. this has proven to be able to restore the stability of social, political and economic conditions in the country. although there has been no research that examines the success of applying cultural intelligence to peacekeeping missions in the democratic republic of the congo, dss vol. 3, 2022, pp.67-73 72 the success achieved by the garuda xii contingent on peace missions in cambodia should be applied in order to achieve conflict resolution that is accepted by all warring parties in the democratic republic of congo. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. acknowledgements thanks are addressed to rear admiral tni (ret.) dr. siswo hadi sumantri., st., m.mt., m.tr.opsla., ciqnr., ciqar., ipu and tni first admiral (ret.) dr. m. adnan madjid, sh., m. hum. as a research supervisor while 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[29] j. b. haseman, "garuda xii: indonesian peacekeeping in cambodia," joint force quarterly, pp. 89-94, 1996. microsoft word 50-57_195 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.50-57 https://doi.org/10.37868/dss.v3.id195 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 50 review of indonesian government policy in procurement plan of dassault rafale fighter aircraft a. wardana1, t. b.cahyana2, h. tahdi3, y. h. yogaswara4 1,2,3,4 faculty of defense technology, indonesia defense university, indonesia *corresponding author e-mail: achmad.wardana@tp.idu.ac.id received: aug. 16, 2022 revised: aug. 29, 2022 accepted: sept. 1, 2022 online: sept. 5, 2022 abstract indonesia's decision to procure 4.5 generation rafale fighter jets has been approved to replace obsolete aircraft, namely the us-made f-16 and the russianmade su-27 and su-30. the selection of rafale was based on indonesia's defense relationship with france which had existed for a very long time, besides that it was also based on the foreign policy adopted by indonesia, namely the free and active policy shown from several defense equipment owned by indonesia, not only from a particular country. this study aims to examine government policies in the plan to procure dassault rafale fighter aircraft for indonesia. this study uses a descriptive qualitative approach through a literature review from reputable national and international journals, ebooks, and online media by exploring or explaining more broadly the government policy issues in the plan to procure the dassault rafale fighter aircraft for indonesia. the findings of this study indicate that indonesia is still lagging behind vietnam, thailand, and singapore in terms of the number of first-tier modern combat aircraft that are ready for combat. in addition, purchase of the dassault rafale aircraft must provide effectiveness to improve national defense and security by using a definitive combination of "highlow" that can be adopted from the usaf (united states air force), and also indonesia must be realistic in responding to the regional balance of power (asean) through the realization of the mef towards ief. one important factor that needs to be considered in the procurement agreement is the existence of a strong policy and commitment from the government that emphasizes the transfer of technology (tot) by sending human resources to study and do internships in the development industry. © the author 2022. published by arda. keywords: dassault rafale, combination high-low, transfer of technology, mef, ief 1. introduction the process of globalization has touched various fields of human life, in the fields of education, socio-culture, economy, politics, defense and security. they are never separated from the effects of globalization. the transformation process that aims to make people around the world into a single society and interdependent on each other is growing rapidly due to the sophistication of information and communication technology. however, the occurrence of the globalization process as a process that will bring the world under one control dss vol. 3, 2022, pp.50-57 51 through one global power has resulted in the dominance of the world community by countries that have great powers that are able to take a role in the process. [1] for indonesia as a developing country with an area that stretches from sabang to merauke and with the fourth largest population in the world, it has not been able to take advantage of the momentum properly. indonesia's strategic position has been used by other countries in various forms, indonesia is used as a consumer in trade for other countries' products, so that indonesia is only used as a market. as an independent and sovereign country, it is fitting for indonesia to increase its defense and security forces. in order to protect the sovereignty of the nation. moreover, in recent times there have been frequent conflicts in the border areas due to illegal fishing by foreign vessels flagged by vietnam, malaysia, china and several other countries that consciously take natural resources and wealth. indonesian sea. besides that, the confrontation carried out by the chinese state over the south china sea dispute by sending several warships in the indonesian maritime border area allowed an open war for the countries with an interest in it. this further emphasizes the importance of the strength of military weapons for the defense and security of the nation. mainly to anticipate conflicts in the southeast asian region by strengthening the military weapons of the indonesian national army (tni). indonesia continues to strengthen its military defenses under the command of defense minister prabowo subianto. recently, indonesia entered into a contract to purchase one of the most sophisticated types of fighter aircraft in the world to improve defense and maintain indonesia's air sovereignty. airspace is one of the most important defenses in military defense. from the news on defense minister prabowo's working visit, the dassault rafale multirole generation 4.5 from france is the strongest candidate, in addition to the hope to get an aircraft from the united states f-15ex. indonesia will buy 42 rafale aircraft and hopes to become the owner of 8 f-15ex. [2] the purchase of 42 rafale fighter planes by defense minister prabowo subianto in early 2022 raised pros and cons. apart from that, the purchase of 6 rafale-type aircraft (36 planes will follow) with representatives of dassault aviation in jakarta, on thursday (10/2/2022). [3] buying a new fighter aircraft is an optionstrategic political and military. this decision, of course, is not just a purchase for valor, but for the defense and security of the country. if it is not used to actively fight, then its existence must be effective in giving effects that affect the defense and security of the country. therefore, this study aims to examine government policies in the plan to procure dassault rafale fighter aircraft for indonesia. 2. research method this study uses a descriptive qualitative approach by exploring or explaining more broadly government policy issues in the plan to procure the dassault rafale fighter aircraft for indonesia. the research focuses on the strategic plan for the procurement of the dassault rafale and the presence of the dassault rafale in indonesia. data collection is carried out through literature studies originating from reputable national and international journals, ebooks, and online media. the literature study in this study was conducted by searching and studying various literature related to government policies in the plan to procure the dassault rafale fighter aircraft for indonesia. sources of data in this study are books, journals, website pages and other references that are considered relevant to the theme in this study. the author uses data analysis techniques with qualitative descriptive analysis strategies. 3. results and discussion 3.1 global free power index the global free power index is one of the institutions that assesses the military strength of all countries in the world, indicators that assess a country's military strength include several aspects. among them are geography, the number of troops, the strength of military weaponry on land, water, and air. until the military budget becomes an assessment aspect. according to several public releases, such as the global free power index, currently, the indonesian air force only has about 445 aircraft forces. this fleet consists partly of second-tier dss vol. 3, 2022, pp.50-57 52 light fighter aircraft that are running down. meanwhile, the total area of indonesia that must be covered is 1.9 million km2. this does not include important flashpoints, such as the south china sea, natuna waters, the malacca strait, and parts of the eastern region, which need more attention and fleets. [4] table 1. air force comparison of several asean (source: gfp index, 2022; processed data) countries total aircraft strength fighter/interceptors dedicated attack transport trainers indonesia 445 41 23 66 126 malaysia 144 26 12 18 39 thailand 496 74 18 50 130 singapore 224 100 0 9 36 vietnam 218 75 0 9 30 myanmar 280 55 21 26 93 philipines 182 0 25 21 24 cambodia 23 0 0 4 0 laos 32 0 0 1 4 the data above shows that indonesia's total aircraft strength sub-indicator is at 445 which only loses to thailand at 490, then on the transport sub-indicator, indonesia is superior compared to other asean countries, namely 66. in matters of the number of first-tier modern fighter aircraft that are ready for combat, indonesia is also still lagging behind vietnam, thailand, and singapore. indonesia's lack of hitting power in air defense, as the largest country in asean, is quite a contrast to some of its neighbors. in terms of the number of air force personnel, indonesia has an estimated 37,850 personnel, which is still less than thailand with 47,000 personnel, whose area and total population differ greatly (270 million vs. 70 million), and is almost on par with vietnam (95 million people). million people) with a total of 35,000 air force personnel. for this reason, as an effort to anticipate conflicts and attacks on a country, the maintenance and renewal of the main weapon system for each country is very important. the modernization of military power is also influenced by advances in defense technology. this reflects alertness, and valor as a nation (ksau marsda tni dr. umar sugeng hariyono, s.ip, s.e, m.m.) 3.2 strategic considerations indonesia plans to purchase a number of major modern weapons systems in stages until 2024, in order to fulfill the strategic plan for phase iii of the tni's minimum essential force (mef) program. some of the defense equipment to be purchased includes 8 units of multirole combat aircraft f-15 ex (united states) and 42 units of dassault rafale fighter aircraft (france). although there are guidelines for posture, strategic plan and mef, the procurement of defense equipment basically depends on the conditions of the strategic environment that continue to change dynamically. in addition, the procurement of defense equipment also has a contribution to defense diplomacy efforts with other countries of strategic value to the global political constellation. the purchase of these two fighter aircraft can also increase the deterrence effect for indonesia in the region. previously, indonesia planned to procure russian-made fighter aircraft, namely the sukhoi su-35, but the purchase plan was not forwarded by the ministry of defense and tni headquarters. the plan to purchase the dassault rafale & f-15 ex is considered a wise step amid the united states' implementation of the countering america's adversaries through sanctions act (caatsa). caatsa is a rule applied to impose sanctions in the form of sanctions and embargoes against countries that buy weapons from russia, iran, and north korea. [4] the addition of the main fighting force is a very important requirement for indonesia. from the global firepower it is clear that indonesia's air combat power is still relatively inadequate. purchasing more precise fighter aircraft is the key word. if it is assumed that the purchase of rafale fighter aircraft is in accordance dss vol. 3, 2022, pp.50-57 53 with the plan, then the combat power of the indonesian air force will increase from 461 units to 503 units of defense equipment. [5] 3.3 combination “high and low” buying a new fighter is a strategic political and military choice. the decision to operate it is not just a purchase with a certain ability for valor but for military defense. if it is not used to actively wage war, then its presence must be effective in providing a deterrence, which also affects regional security and as part of the country's political tools. in concocting fighter aircraft postures, we can learn from the usaf example (united states air force), which uses the definitive combination of "high-low". the usaf does not rely on one type of advanced aircraft but operates several types of fighter aircraft, designed for a specific mission and simplified into two. that is, those with high abilities (high) and those with abilities below (low). table 2. fighter aircraft category fighter aircraft high capability fighter aircraft low capability gd f-111 boeing f/a-18a atau f16 sukhoi su-32fn/34 dassault rafale sukhoi su-27/30/33 eurofighter typhoon boeing f-15k/sg lm f-16c lm f-22a joint strike fighter f-35 "high" fighter aircraft dedicated to air superiority (air-to-air combat). the specifications are very high speed above mach 1.5, long range, sensitive advanced radar, advanced computer that can identify and track multiple targets at once, and can carry multiple air-to-air missiles. the main role of the "high" fighter aircraft is to clear the air combat zone of enemy fighters and air defense systems. this makes the combat area relatively safer for other vehicles, such as tactical bombers and helicopters, which are more vulnerable to attack by aircraft and anti-aircraft defense systems, from that function emerged the f-15 eagle and now its successor is the f-22, the su35, su-57. however, of course this existence is very expensive and requires a high commitment with a long process. therefore, the production of "high" class fighter aircraft is not as high as other classes, and the fleet is also specialized in the elite tier. while the high demand due to conflict persists, the solution is to design a second tier fighter, which has been reduced in specifications and is definitely cheaper. however, the line which was less sophisticated than the first tier was covered by a sizable quantity of the second tier fleet. for "low" fighter aircraft, its main role is to strike the ground with more air-to-surface. air-to-air missiles still exist, but only as a limited support tool for self-defense. "low" fighter planes will rely on their friends "high" fighter planes to guard and defend themselves from enemy threats. “low” fighter designs are usually smaller and have a shorter cruising range. the maximum speed is lower, the radar is not as sophisticated as the “high” class, and the avionics are simpler. an example of a fighter of this category is the f-16 fighting falcon, then now there is the f-35. [6] 3.4 mef to ief according to the expert staff coordinator (koorsahli) ksau marsda tni dr. umar sugeng hariyono, s.ip, se, mm, in his doctoral dissertation explained that the indonesian air force is still far from the ideal number of aircraft fleet needs with a total of around 600 units. the plan to develop the power towards the ideal essential force (ief) for the period 2024-2039 requires at least 348 aircraft to be added. [7] assuming the posture of the fighter aircraft is in the 30-40% range, it means that the indonesian air force still needs more than 100 units of first-tier modern fighter aircraft (comparable to and above the f-16 specifications) to reach the ideal essential force (ief). in practice, the air defense posture of each country or defense agency of course does not or cannot be exactly the same as the usaf's, due to financial constraints and so on. however, the basis of reference for the us setting the definition of high-low was because it had been actively fighting in dss vol. 3, 2022, pp.50-57 54 various combat theaters outside its own territory. of course, the indonesian air force is not required to have 100% same definition of fleet posture, but the usaf approach can be adopted, according to the advantages of each type of aircraft that can be acquired. [6] if indonesia's current free-active policy tends to be oriented towards the us and allied defense equipment, the posture of its fighter aircraft can modify the usaf high-low, to then equalize its position with thailand and approach or slightly exceed singapore. the uniformity of the fighter aircraft fleet is very important, especially since the tni is currently strengthening its network centric warfare system. the strength of the indonesian air force cannot be dominated, for example, by fighter aircraft made in the us vs. russia. this is because it will cause system conflicts in the field, in addition to disrupting the smooth interoperability of the three dimensions. not only is it an up-to-date fighter specification, but the presence of an ideal fighter combination at the outermost air base, and cruising range (including response time) around flash points is imperative. [6] plan a is a combination of f-15ex aircraft (not yet us approval), rafale (bright, but not final), old f-16s, and some sukhois. however, indonesia must also have a plan b. for example, the rafale is the "high" aircraft, and the f-16 is "low". then, another decade or two, the f-16 was dethroned by the rafale, and the "high" role was filled by the f-15ex or f-35 and others. [6] 3.5 rafale fighter aircraft secretary general of the ministry of defense marsdya donny ermawan taufano in the webinar 'welcoming the rafale plane', said that indonesia currently only relies on 33 f-16 aircraft that are more than 30 years old. meanwhile, 16 sukhoi su 27 and su 30 fighters are almost 20 years old. under these conditions, it is the obligation of the ministry of defense to plan fighter aircraft that will serve in the 2030s and 2040s. the government's decision to choose the rafale fighter is based on technical and non-technical considerations. choosing products made in france is safer from us sanctions against russia or better known as caatsa (countering america's adversaries through sanction act). this is inseparable from the military competition between the us and russia. in addition, the certainty of technology transfer of the rafale fighter is more secure than the previous two types of fighter aircraft. [8] rafale is known as a versatile aircraft because it can be used for various missions. for example, interdiction (ban), aerial reconnaissance (air reconnaissance), ground support (ground support), anti-ship strike (anti-ship attack) and nuclear deterrence mission (nuclear prevention mission). dassault rafale fighter specifications: 1. generation 4.5 aircraft. 2. maximum speed 1.8 mach or 750 knots. 3. maximum altitude 50,000 feet. 4. has an 'active electronically scanned away' radar. 5. has a wingspan of 10.9 meters, length 15 .30 meters and 5.30 meters high. armament specifications dassault rafale: 1. the mica combat and self-defense missile. 2. meteor long range rocket. 3. high agile and manouvrable munition extended range equipped with gps and infrared. 4. aircraft-brake-powered air missiles. 5. scalp long range missile. 6. am39excocet anti-ship missile. 7. laser guided bombs with warheads ranging from 500-2,000 pounds. 8. internal gun with 2,500 rounds/minute nexter30m791 mm in addition, for special missions, the rafale can deliver mbda nuclear missiles. with the addition of the main combat defense equipment in the form of the rafale type fighter aircraft, it is certain that the combat dss vol. 3, 2022, pp.50-57 55 power of the indonesian air force is the strongest in southeast asia for now. however, it must still be noted that the very large area of the air boundary with the four sector commands (kosek) of the national air defense command (korhanudnas) which includes: jakarta, makassar, medan and biak is not sufficient. the current number and posture of the main combat defense equipment can only support a maximum of 30 units per korhanudnas. seeing the development of the global geopolitical situation which is full of uncertainty after the start of the russian invasion of ukraine, the indonesian government needs to consider the fulfillment of the main combat defense equipment which is relatively adequate, sophisticated and modern. thus, the sovereignty of indonesia's airspace is not easily threatened and violated by foreign parties and is protected from enemy attacks if at any time there is a war between indonesia and other countries. 3.6 transfer of technology transfer of technology is one way to eliminate the limitations that hinder mastery of technology and towards increasing mastery of technology. the policy is a strategy in developing the capacity of human resources so that their productivity will increase even more. increased human productivity will produce quality and competitive products. [9] in the contract for the purchase of 42 rafale aircraft made by dassault, a memorandum of understanding (mou) of the offset and tot program cooperation between dassault and pt di was also made. the dassault rafale aircraft procurement contract agreement should emphasize the transfer of technology (tot) by sending human resources to study and do internships in the development industry. in addition to hr offsets, there is also a need for an offset scheme for the production of aircraft components in indonesia by the national industry, namely pt dirgantara indonesia (pt di). as a strategic national asset, pt di requires continuity between human resources and facilities that are recognized by authority globally. pt di's business portfolio consists of aircraft (airplane and helicopter), aircraft services (maintenance, overhaul, repair and alteration), aerostructure (parts and sub assemblies, assemblies tools and equipment), engineering services (communication technology, simulator technology, information technology). solution, design center) should focus on optimizing the national aviation system as a provider and supporter of commuter aircraft and tni defense equipment. the development strategy must prioritize the importance of the independence of the nation and the mastery of technology by the nation's own children. for this reason, the government needs to include elements of science and technology for human resource development in the defense equipment spending agreement. it must be admitted that the human resources we currently have are still limited, both in terms of quality and quantity. hr is the main component in determining the success of r&d work. the limited quality and quantity of technology experts will only shackle the r&d function. r&d is a bridge that connects science and technology with human interests. therefore, r&d agencies must be supported by qualified technology experts and in sufficient numbers. every effort and effort must be made to increase the number of transfer of technology (including transfer of technology/tot) of a general nature, or military, in accordance with the demands of the required disciplines. [10] the development of the defense technology industry does require a strong commitment from the government. this commitment is certainly related to the development of the defense industry, including the offset policy in it, as an effort towards indonesia's defense independence. the government holds the main control in the development and implementation of offset policies because the support of funds, human resources, and political will is very much needed. however, if this policy is carried out optimally, we will see an independent indonesia and talk a lot on the international stage. [11] in addition, the role of academics can help maximize the absorption and dissemination of knowledge that can help smooth the transfer of knowledge needed to support technology transfer. in addition, influential factors in technology transfer include production facilities, managerial capabilities of human resources, and government commitment in transfer projects. technology. in technology transfer, a large investment is needed to prepare the required production support facilities. dss vol. 3, 2022, pp.50-57 56 investment is needed to support the success of the technology transfer process. the success of technology management in a country depends on the political commitment of the government to be able to increase mastery of certain technologies, such as making regulations that support the achievement of mastery of technology, and other supports such as financial support aimed at the success of technology management in the context of mastering certain technologies. [12] defense minister prabowo's military diplomacy, which has been active for the past year, must be able to produce concrete results. it must no longer run aground, such as the planned acquisition of the su-35 and the development of kfx/ifx, where almost a decade has been wasted, swallowing the bitter pill of defense equipment politics and the complexities of aerospace technology. the issue of the balance of power in asean and the potential conflict between the south china sea and china are definitely part of indonesia's ammunition, in lobbying for defense equipment needs to other strong democratic countries, such as the us and its allies. the successive governments must also faithfully guard this vision and commitment. [6] 4. conclusions based on the results of the analysis, conclusions can be drawn in this study as follows. the existence of indonesia, which is in the southeast asian region as well as bordering the pacific ocean, makes the country characterized by the archipelago must have a military force that is capable of dealing with various external threats. especially in the southeast asia region. so that the strength of military weapons for a country is very important to anticipate various threats that have the potential to come to disturb the security and peace of a country. fighter aircraft dassault rafale that has been carried out by the ministry of defense so that its existence becomes effective in formulating defense postures, the usaf approach (united states air force) the definitive combination of "high-low" can be adopted according to the advantages of each type of aircraft that can be acquired. in fulfilling its defense equipment, indonesia must also be realistic in responding to the balance of regional power, namely asean. the realization of the mef towards ief must adapt, for example, to the air power of three strong neighboring countries, such as vietnam, thailand and singapore. thus, the sovereignty of indonesia's airspace is not easily threatened and violated by foreign parties and is protected from enemy attacks if at any time there is a war between indonesia and other countries. the dassault rafale aircraft procurement contract agreement should emphasize the transfer of technology (tot) by sending human resources to study and do internships in the development industry. in addition to hr offsets, there is also a need for an offset scheme for the production of aircraft components in indonesia by the national industry. this policy does require a strong commitment from the government. the government holds the main control in the development and implementation of offset policies because the support of funds, human resources, and political will is very much needed. if this policy is carried out optimally, we will see an independent indonesia and speak a lot on the international stage. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] m. a. wibowo, "eksistensi tni dalam menghadapi ancaman militer dan nir militer multidimensional di era milenial". kemhan ri : edisi khusus (wira), 2019. [2] t. p. sorongan, "prabowo borong 42 jet tempur rafale", cnbc indonesia, 2022. dss vol. 3, 2022, pp.50-57 57 [3] f. c. farisa, "deretan alutsista yang di beli prabowo". kompas, indonesia, 2022. [4] a. fitri, p. dalam n. kepakaran, s. pertahanan, p.penelitian b.keahlian sekjen, dpr ri, 2022. [5] mujiburrahman, "menakar kekuatan tni au pasca kontrak pembelian rafale", politik dan keamanan budget issue brief vol 02, ed 3, maret 2022. [6] d. toruan, "menanti kombinasi maut jet tempur indonesia", armory reborn 6, 2021. [7] f. setiawan, "menuju ideal essential force (ief), indonesia perlu menambah 348 unit pesawat untuk tni au, air space riview, 2018. [8] b. santosa, "pembelian pesawat rafale," kompas, indonesia , 2022. [9] m. waluyo, "transfer teknologi dan keberlanjutan industri", lipi, 2018 [10] i.samego, s. pertahanan-keamanan negara, "analisis potensi dan problem", (jakarta: the habibie center, pp. 227-228, 2001. [11] r. m. j. indrawan, "kebijakan ofset dalam membangun kemandirian pertahanan negara", 2016. [12] r. l. muchtiwibowo, "transfer of technology," jurnal industri pertahanan, volume 1, no 1 , 2019. microsoft word 44-52_149.docx issn 2744-1741 defense and security studies review article vol. 1, december 2020, pp.44-52 https://doi.org/10.37868/dss.v1.id149 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 44 quality management research trends in context of industry 4.0: a short review benjamin rudalija1 1 mechanical engineering, international university of sarajevo, bosnia and herzegovina *corresponding author: benjamin18rudalija@gmail.com © the author 2020. published by arda. abstract with new century we have new revolution which is industry 4.0. that industry is helping companies to create smarter products together with services in such way that companies will reduce costs and they will increase efficiency. in that operation, human factor is crucial for the application. one of the benefits of the industry 4.0 is the smart factory that makes a solution. that is leading to the automated procedures. also, it is leading to the uncomplicated setup including simple installation and sometimes very high rate of scalability. all of this feature will help companies in the manufacturing process and further optimization their own processes. in the end, it will boost up their efficiency from the aspect of manufacturing. with digitalization of major industries, almost 5 million workplaces can be lost by 2020. in the same time, it will stop really fast the market demand for product which are produced using outdated technologies. because of that, such production would be shut down because of higher costs and inefficiency in the first place. keywords: industry 4.0, quality management, innovation 1. introduction quality management is topic that is discussed in today’s contemporary world. today, we have technological dominance in our lives, and technology is in every aspect of our everyday activity. scientists are telling even technology is helpful, but it can be dangerous. so, this problem is taken to be part of development in quality management in the industry 4.0. goal of 4.0 era is to focus to unravel advancement of quality and its implications in terms of economics, decision models, business models, human and technological perspectives etc. some key terms are: 1) quality management. 2) industry 4.0. 3) technology. 4) quality culture. 5) behavioral aspects. we have to know what term industry 4.0 means. industry 4.0 is a part, or better to say subset of fourth industrial revolution. industrial areas which are not considered as a real industry are considered as part of industry 4.0. example can be smart cities, or smart cars. term industry 4.0 or ''fourth revolution'' has machines which are working with wireless connection. also, in those machines is a lot of sensors which are connected to the system which tracks every part of production process and making decisions by its own. so, a type of ai (artificial intelligence). industry 4.0 is using different manufacturing technologies and processes. some of them are cyber-physical system (cps), the internet of things (iot), cloud computing, cognitive computing, industrial internet of things (iiot) etc. dss vol. 1, december 2020, pp.44-52 45 so, the concept of quality management is very young. that concept wasn't understood before 1980's. during the 80s and 90s, concept of quality management became famous. from different studies we can see that the suggest quality environment can be created in such way that everybody are inspired to have feeling that they are responsible for it. it is very important to have good quality cost. poor quality cost can be cut through leadership emphasis, message credibility, peer involvement and employee empowerment. poor quality incurs companies 5% to 30% of their annual sales but companies with strong structured quality system spend 350 million dollars less than poorly structured quality systems. one of the objectives is to ascertain control limits of quality to address problems like inflexibility, customization, longer supply chains. one of the solutions is to include statistical quality control techniques, but better choice is to look for innovative techniques. 2. short history of industry as the name is telling us, industry 4.0 is fourth type of industry in human history. but we can't talk about this industry if we don't know what happened before. also, people can learn a lot of things based on industries before such as 1.0, 2.0 and 3.0. all those historical discoveries changed human kind forever, but time is going on. so is the industry. pathways in industry 4.0 can be based on (some of them) the previous industries. industry 1.0 importance of this industry was huge. at the end of the 18th century, steam engine is discovered. that discovery changed industry from the ground. with making steam engine, people started to use heavy machinery. industry 2.0 the second industry revolution is based on using the electricity. with this discovery it was possible to use a conveyor belt and assembly line. industry 3.0 in this industry, most important pathway was introduction of automatization of production processes using electrical energy and using information and communication technologies. industry 4.0 finally, the evolution of cyber technologies and their integration into digital ecosystems along all values chains contributed to the emergence of the fourth industrial revolution called “industry 4.0”. the first concept of industry 4.0 was presented at the industrial technology fair in hanover in 2011. since then, many different companies started to developed solutions in line with the concept of industry 4.0. many governments also support the development of such solutions, especially european governments (with an emphasis on the german government), usa and japanese government, confirming that this new industry is viewed as a strategy by major industries in the world. in general, the main purpose of industry 4.0 is the emergence of digital manufacturing, also referred to as “smart factory”, which means smart networking, mobility, flexibility of industrial operations and their interoperability, integration with customers and suppliers, and the adoption of innovative business models. 3. stages of formation of industry 4.0 and the key indicators of its development in this following text i’m going to provide the study of the main stages of formation related to industry 4.0. also, main goal is to determine the key indicators of development. important things are to analyze the process of formation of industry 4.0 which is going to be described below. after reading the text you will be able to distinguish the main stages which are: formation of industry 4.0 as a sphere of industry. transition to industry 4.0. preparation of the socio-economic system. as in every system, industry 4.0 has some potential barriers on the path of formation at each of the stages and there must be offered recommendations for overcoming them. people developed and present the system of dss vol. 1, december 2020, pp.44-52 46 indicators which are related to monitor the formation of industry 4.0 which basically includes target values of indicators for moving to the next stage of industry. we can conclude also that economic system of today’s world modern economic system is in different stages of the process related to the formation of industry 4.0. today in the world we can see that some developed countries developed the transition of the second stage while other countries who are in transition time have just started the first stage of the process. so, talking about large scale of global economy system, industry 4.0 should be conducted in long term scale. every day our global economy is developing and in certain moment we have different trends. the same situation is with industry 4.0. people think that actual trend in the world is developing industry 4.0 from aspect of the global economy, but that is not a case. this development is related to the future. as it is, that development can stimulate people to achieve strategic goals from which are based in core of the industry. landmark in modern global economy system is development of knowledge of economy. that landmark is provided from tool called industry 4.0. knowledge economy is recognized as the most important and optimal type in today’s economic system. firstly, knowledge economy is very long and complex process. even though people want to improve the system and other things, there is a lot of obstacles on that path. many of them are low effectiveness of the existing tools (some of them are growth vectors). this problem is real and it comes from experience. so, in other to reduce risk component of the process and process information of the knowledge economy and in the same time to increase the effectiveness due to acceleration of the economy rate and economic development, industry 4.0 allows that. industry will diversify these tools in other to help in development. second, industry 4.0 can be viewed from the different angle. it can be viewed as a self-goal. in that manner, it will push the achievements of sustainable socio-economic development. what industry 4.0 provide is reduction of labor. even the intellectual load on modern human will reduce. the things which have exponential growth is production and innovational development of economic system. so, this is one of the research pathways in the industry 4.0. different and better economic system. to achieve this, economic system must be increased by efficiency, also with reduction of resource intensity. the level of real income of population should also be increased. due to this reasons, concept of industry 4.0 is large in term for high scientific and practical significance. so, this can help us to explain studying of some potential problems that may occur, possibilities and perspectives of implementation in the economic practice of today's modern socio-economic systems. the main goal of this research paper is to determine and discuss the main stages in the industry 4.0 and also to show us main key indicators of its development at each of them. industry 4.0 (i4.0), even if very young in revolution, has several main pillars or categories which are very important in the future development of the revolution. also, these main pillars will explain the research pathways inside this revolution. it should be mentioned that i4.0 is still in development; every day practically, so, some things we have but some things we don't have. so, we can say that we are still in revolution. 4. the main pillars in industry 4.0 in the following text i'm going to describe some of the concepts of the i4.0. those concepts are main bases of this industry and some of them are still in progress. those are: 1) big data and analytics. 2) autonomous robots. 3) simulation. 4) horizontal and vertical system integration. 5) the industrial internet of things (iot). 6) the cloud. 7) additive manufacturing. 8) augmented reality (ar). 9) cyber security. 4.1. big data and analytics concept of big data sets is affecting the decision making inside the company using large, diverse and very complex datasets. this can affect the strategy of the company. for example, if company invest in this field, big data means big things. in other words, increasing in level of data will improve the company’s features like competition among other companies, it will increase productivity and most important innovation. big data are giving big projects to company because more opportunities are there. a lot of decision makers are giving big data projects to solve challenges in organizational levels. dss vol. 1, december 2020, pp.44-52 47 the big data can be described in several ways: data as a tool, data as an industry, data as a strategy. using framework of the big data as a tool is described as solving traditional values or chain of values problems using existing capabilities. using framework of big data as an industry is actually act of using new developed software for handling big data in the future. last, using framework of big data as a strategy is actually making new data resources by development of new models in business which are innovative. regarding the process of big data analytics is actually to analyze large number of datasets. those datasets will give information about customers; mostly that information will be the trends and preferences. datasets will also contain algorithms in case of some correlations. in sets of algorithms, those can be used also for prediction of reducing error probability [1] or big data analytics can be consisted of algorithms which are predictive they can reduce harm before damage is done [2]. if big data can be manageable, and they can, then people will have advantages out of it. mostly that is going to be competitive advantage to the firms which means they will have benefit in their own operations, customer experience, marketing also and etc. generally, i4.0 is the era of technology. with more technological changes and shifts, more companies will manage mainstream business practices. they will start to increase infrastructure development. we can conclude that big data is pushing companies in more complex aspect of their business. in the today’s world, we can see increase in data that is processed and generated by machines. big data concept takes the very big and important role in i4.0 [3]. 4.2. autonomous robots another important aspect of the industry 4.0 is autonomous production. this type of production is powered by concept called “internet of things” (iot). the idea of this concepts is to have communication between different objects, computers, devices and machines by harnessing with each other. regarding this concept, autonomous robots are the best example. even if in the beginning using robots in industry looked very easy, it was not a case. today, connecting robots to a central server, programmable logic controller or big database can be coordinated and more automated than ever before. robots can complete tasks intelligently with minimal human input which is very important. autonomous mobile robots (amrs) can transport things inside the factory with avoiding obstacles, or coordinate with fleet mates, they can identify where pickups or drop-offs are needed in real time etc. we know that almost in all aspect of the industries robots are used and they will be used in all sorts of every industry and we can’t predict the moment of that change. today we have the system “machine-to-machine” but industry 4.0 is going beyond that scope. some of the components of the facility which are not considered as “machines” can be connected together as well and they can be treated as “machines” like robots. environment in which they are used is called digital ecosystem. with acceleration of industry 4.0, the usage of the robots is also accelerating because industry requires more production, logistics, distribution and all of that can be controlled by human remotely. that remotely control is communication between human and robot. also, during the evolution of the i4.0, some of the new robotics technologies are developed such as kuka lbr iiwa which is doing sensitive tasks and collaborate with people too. robot with this system is able to learn from humans and also to check, optimize and document different tasks by help of different cloud systems [4]. 4.3. simulation simulation is very important in i4.0. it is playing an important role in production in such way that is promoting sustainable manufacturing environment in the company. digital tools are heavily used in order to achieve certain design in the system of production. they have ability of self-configuration which means it can establish effective shop-floor management. inside the competitive business, simulation can offer different adjustments to complex systems in such way that operations are planned. also, simulation offers knowledge and information together with accurate estimations about certain system, which is achieved by using the engineering capacity [5]. even the strategic plan can be done using the simulation models which can help to make dynamic plan for different production systems. in those plans, simulation will do processes in real-time which means simulation is acquired. any system that is using simulation as a help tool can create real time optimization in every operation [6]. dss vol. 1, december 2020, pp.44-52 48 4.4. horizontal and vertical system integration there are two different systems inside the factory, horizontal integration and vertical integration. vertical integration is flexible system which is inside the factory. horizontal integration is related to integration of partners which is connected with the scs. network inside the industry is collecting big data with mission to optimize the system and system performance and also to send those data to the cloud. this connection is actually creating the framework of the smart factory. with this system, we are helping the manufacturing system to make self-organization structure and every physical object is connected with other by smart networks. in the other hand, cloud system can integrate multiple vertical partners into each other using the shared platforms which are created. all of the production and processes are tracked by members of sc [7]. 4.5. the industrial internet of things (iiot) internet of things (iot) is actually the next technical revolution in the i4.0. iot is able to give solution for different computations or analytics. those calculations are related to data which are stored in cloud systems. main purpose of the iot is connect the internet by collecting all of the data from physical objects inside the factory. with data collecting, computers or other devices are able to make decision about certain operations [8]. with iot, operations in the business are more agile and also, they are integrated in the same way as achieving competition on the basis of sc is. so, we can conclude that using the iot will be crucial in the future. it will mostly help with agility and very effective decision making in the production and other processes [9]. 4.6. the cloud cloud computing or cc is bringing the different advantages in the ict paradigm. some of them are helping scs to the automatization and integration but also there are advantages related to management and administration. that is the way of virtualizing the resource and it helps to combine the system based on clientserver. cc is including pools of many it resources that offers storage in virtual system. also, it offers processing capabilities in variety of virtual system by serving more than one user. cloud computing has three different models; saas which stands for software as a service. in this computing system access depends on the purchase of the customer. next computing is paas which stands for platform of the service in which customers are allowed to have access to their application on the cloud (software developers mostly). last subgroup is iaas which stands for infrastructure as a service. in this computing system, customers are offered some basic activities. one of them is storing capability. one of the best examples of cloud system today is actually google drive provided by google. other examples are windows azur provided by microsoft or bluecloud created by ibm company [10]. 4.7. additive manufacturing this field of i4.0 called additive manufacturing is also defined as 3d modelling or printing. 3d printing is used for producing goods with different requirements provided by customers. 3d printing is very popular today because it can save a lot of time by producing limited batches or limited edition of products which means that other machines will have less stock on their process of production. many companies today are using 3d printing to reduce the weight of the airplanes. other materials used in this industry are titanium and other metals. one of the leading companies who are investing in 3d printing technology are apple, google and motorola. main reason of that investment is to continuous smart phone production. in 3d printing, some processes as machining and milling are completed in stages; layer by layer. that means 3d printing is making a lot of products using less resources [11]. 4.8. augmented reality (ar) augmented reality (ar) is actually technology which is used for interaction that helps to establish harmony between virtual world and users. in the same time, that virtual world is used as part of the real surroundings. one of the examples of this technology are google glass reality glasses. other example is magic leap created in 2011. magic leap has ability to adjust to the human eye by converting light field angle and depth [12]. technology like this is increasing the communication between human and the machine. things like remoting control and visual inspection of the humans are provided virtually too using ar. if computer generated graphics and physical object are combined, it can be used in many different applications. ar is using sensors mostly in order to give users motion control on the certain tasks. dss vol. 1, december 2020, pp.44-52 49 4.9. cyber security one of the issues in the i4.0 is cyber security. with development of technology and together with implementation in our lives, cyber security can have very bad and destructive impact on the business, business environment, for example terrorist attacks. so, with development of the i4.0, people have to have some solutions or defense systems which are necessary. in this industry people can use some previous terrorist attacks and use that bad experience in order to protect people from future attacks. even if costs of preventing the cyber war will cost the companies a lot of money, in the end, total cost is not to high if we take into account potential negative effects of the cyber war or attacks [13]. table 1 is representation of the summary of the concepts that explain the vision of the future in industry 4.0. table 1. future of industry 4.0. 5. six countries leading in the fourth industrial revolution industry 4.0 is slowly taking place in the world. even if 21st century is era of technology, not all countries all capable to take i4.0 as a new friend. only strongly developed country can take leader place in this industry. today in the world we have 8 of them, those are:  canada  japan  germany  australia  austria  switzerland  usa  china i will shortly explain all of these examples. these 6 countries are taken from the research in 2019. dss vol. 1, december 2020, pp.44-52 50 1) canada today, canada is 1st country in innovation in technology. that innovative technology includes anything starting from blockchain to ai all the way to the complete digitalization. government of canada even trying to blockchain their own communication system. even though canada is taking very high place in implementation of industry 4.0, they don’t stop to “research” this field. they have a lot of opportunities for investment and another innovation in the industry 4.0 and new business. in the list of wef’s drivers of production, canada ranks a reasonable 33rd place with the current structure of production in the country. also, canada is taking 7th place as a driver of production in the list. some people predict that canada can pioneer the state of production in world if they take that journey slowly with a lot of time and preparation. 2) japan another leading country on the wef's list is japan. japan has very strong structure of production today which is interesting even if japan doesn't have so much natural resources. among developed countries, japan is very strong player, especially in manufacturing and production (cars, robots, dig. equipment). as we know, everything in the nature has balance. same situation with japan. even if they are very good player for i4.0, they have another problem related to social challenge increasing in ageing of population. but new industry can provide good solution to japan. solution is called “society 5.0” which is actually trying to help and solve some problems created with implementation of industry 4.0 technology. society 5.0 is like older brother to industry 4.0. japan is building ideas which are based on idea of “monozuri”. that idea is related to work ethic in japan and also skills in the manufacturing process. 3) germany japan has its own list of leading countries in implementation of i4.0. on that list, first place is taken by germany. germany even has its own plan and strategy for industry 4.0. some of those strategies are (in first place) workers, promoting of digitalization, smes, businesses and globality. germany has variety of products like ai, blockchain, automation and iiot and they are trying to bring aspect of i4.0 to those fields. they created “platform indsutrie 4.0”, which is moderator of societal and technological exchange. 4) australia australia is not well positioned as one of the leading countries regarding the implementation of i4.0 (current rank is 61st place) but australia has great potential. on the list “driver of production “, australia is taking 12th place. australia’s gdp related to manufacturing sector is very low. it is less than 7% which is very low. even if australia has great potential, right now, manufacturing is on very low level. but some countries recognize that australia can be very good, so they signed an agreement with germany. that agreement is based on collaboration between those two countries in aspect of implementing the 4.0 technologies. 5) austria austria is another country in the europe that is very strong in production. they have very similar plan of production and implementation as germany, with platform industry 4.0 established in 2014. one of the main reasons why austria is so good is that they are “forcing” interplay between different industries. that strategy showed promising because results is joining the strategies together with scalability and transferability. austria is setting mostly on sustainable resources and human capital and country if taking benefits from current state of production and i4.0, also from very good production future and implementation of i4.0. 6) switzerland switzerland is the third country in the europe with good implementation of industry 4.0. this country has good position with current and especially future state of production. on the wef’s list, position is 4th for structure and 3rd as a driver. switzerland also hosts the headquarters of the forum called world economic forum which is held in geneva. together with the germany, switzerland was very good in resisting economic downturn owe the last years, which is not the situation with some other countries. this country is also pioneer in industry 2025 which is planning to unite the companies together in i4.0. 7) usa in year 2014, industrial internet consortium (iic) was founded. on that consortium, more than 100 companies participated. one of them are ibm, intel, general electric, at&t, cisco… the purpose of the dss vol. 1, december 2020, pp.44-52 51 meeting was to discuss and work on the technology of production in the future. again, germany took place here with participation of two companies siemens and bosch. if you check the list, you will see that a lot of it companies are included so the main focus there was talking about iot together with the interconnection of future factories. the industrial internet consortium (iic) is almost the same as policy of industry 4.0. the goal is to have more efficient production, some important processes should be optimized. also, idea is to have higher availability for the machines. the last important topic was to have high level of individualized production in the production system. 8) china according to china and their government, they are planning to build the new system of production. that system is based on the omnipresent information and communication system. they made plan called “advanced manufacturing technology roadmap”. that roadmap has each step written down until 2050. also, plan includes milestones for 2020 and 2030. main goal of china’s industry is to get less dependent on the products which are imported. also, they plan to help different technologies which are related for the production. one of those production systems is automotive sector. “advances manufacturing equipment” is another plan with the highest priority and it has strategy of five-year 6. conclusions with new century we have new revolution which is industry 4.0. that industry is helping companies to create smarter products together with services in such way that companies will reduce costs and they will increase efficiency. in that operation, human factor is crucial for the application. one of the benefits of the industry 4.0 is the smart factory that makes a solution. that is leading to the automated procedures. also, it is leading to the uncomplicated setup including simple installation and sometimes very high rate of scalability. all of this feature will help companies in the manufacturing process and further optimization their own processes. in the end, it will boost up their efficiency from the aspect of manufacturing. with digitalization of major industries, almost 5 million workplaces can be lost by 2020. in the same time, it will stop really fast the market demand for product which are produced using outdated technologies. because of that, such production would be shut down because of higher costs and inefficiency in the first place. at the end of the paper, i present an interesting quote: “the factory of the future will have two employees: a human and a dog. the task of the human will be to feed the dog. the dog will have the task to dissuade the human to touch the automated systems.” (warren g. bennis) declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] w. ji, l. wang, “big data analytics-based fault prediction for shop floor scheduling. journal of manufacturing systems”, vol. 43, pp. 187–194, 2017. [2] p. seele, “predictive sustainability control: a review assessing the potential to transfer big data driven “predictive policing” to corporate sustainability management”, journal of cleaner production, vol. 153, pp. 673–686, 2017. [3] s. yin, o. kaynak, “big data for modern industry: challenges and trends [point of view]”. proceedings of the ieee, vol. 103(2), pp. 143–146, 2015. [4] m. aiman et al., “industry 4.0: a review on industrial automation and robotic”, jurnal teknologi (sciences & engineering), vol. 78, pp. 137-143, 2016. [5] s. weyer et al., “future modeling and simulation of cps-based factories: an example from the automotive industry”, ifac-papersonline, vol. 49(31), pp. 97–102, 2016. [6] t. h. uhlemann et al., “the digital twin: realizing the cyber-physical production system for industry 4.0”. procedia cirp, vol. 61, pp. 335–340, 2017. [7] s. wang et al., “towards smart factory for industry 4.0: a self-organized multi-agent system with big dss vol. 1, december 2020, pp.44-52 52 data based feedback and coordination”, computer networks, vol. 101, pp. 158–168, 2016. [8] h. rahman, r. rahmani, “enabling distributed intelligence assisted future internet of things controller (fitc)”, applied computing and informatics, vol. 14, issue 1, pp. 73-87, 2018. [9] p. akhtar et al., “the internet of things, dynamic data and information processing capabilities, and operational agility”, technological forecasting and social change, vol. 136, pp. 307-316, 2017. [10] k. candel haug et al., “cloud adaptiveness within industry sectors – measurement and observations”, telecommunications policy, vol. 40(4), pp.291–306, 2016. [11] w. e. frazier, “metal additive manufacturing: a review”, journal of materials engineering and performance, vol. 23(6), pp. 1917–1928, 2014. [12] z. he et al., “research on human-computer interaction technology of wearable devices such as augmented reality supporting grid work”, procedia computer science, vol. 107, pp. 170–175, 2017. [13] h. s. cho, t. h. woo, “cyber security in nuclear industry – analytic study from the terror incident in nuclear power plants (npps)”, annals of nuclear energy, vol. 99, pp. 47–53, 2017. microsoft word 1-14_183 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.1-14 https://doi.org/10.37868/dss.v3.id183 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 1 numerical simulations of the formation behavior of explosively formed projectiles minel salkičević* 1 defense technologies department, mechanical engineering faculty, university of sarajevo * corresponding author e-mail: s.minel97@gmail.com received: oct. 13, 2021 revised: dec. 22, 2021 accepted: jan. 12, 2022 online: jan. 16, 2022 abstract an explosively formed projectile (efp) is a self-forging shape charged structure having very high penetration ability compared to conventional kinetic energy projectile. the penetration capability of an efp is strongly dependent on various design parameters. the main parameters can be roughly divided into geometric and material parameters used in the warhead configuration. the present research is an effort to study the effect of metal casing thickness, type of metal used for the casing, explosive type, liner thickness, type, and configuration on the formation of efp. the effectiveness of an efp is studied in terms of the final velocity and shape of the formed penetrator. the study is carried out by performing a number of simulations using explicit finite element (fe) hydrocode ansys/autodyn. © the author 2022. published by arda. keywords: explosively formed projectiles (efp); numerical simulations; ansys/autodyn 1. introduction generally, an explosively formed projectile system consists of a charge, liner, casing, and wave-shaper. the geometric and physical parameters like length, diameter, liner shape material, and type of charge strongly influence the shape and velocity of the penetrator [1]. figure 1. the schematic of efp configuration [1] dss vol. 3, 2022, pp.1-14 2 similar to shaped charge (cumulative) projectiles, after detonation, very high pressure collapses the liner into the appropriate shape (depending on the design) of the penetrator moving at a speed of up to 3 km/s [2]. the process of penetrator formation from the initial shape of the liner is shown in figure 2 [3]. figure 2. the formation process of efp [3] there are two structural types of solutions used in the fight against armored combat vehicles. the first type is anti-tank penetrating mines (with antenna or non-contact, electromagnetic activation mechanism), effective at a distance of up to one meter – one such is shown in figure 3a. the second type are explosively formed projectiles that are used to pierce armor at greater distances (stand-off projectiles) – shown in figure 3b. the penetrating abilities of these two types are different, which results from the way of attacking the chosen target. the first type hits the floor plate or tracks of an armored vehicle (in modern tanks, the floor armor is not thicker than 20 mm). the second type hits the side armor (the thickness of the side armor in modern tanks does not exceed 80 mm), and in modern times also the upper side of the tank armor. the minimum penetrating power of the first type is 40 mm at a distance of up to one meter, and the second type 80 mm at a distance of up to 100 m [4]. figure 3. schematic representation of the solution based on the misznay schardin effect (a-anti-tank mine; b-efp; where: 1-liner, 2-exp. charge, 3-activation mechanism, 4-metal casing) [4] two major applications have evolved since 1975 for efp warheads, namely, long-standoff sensor-fuzed submunitions and medium-standoff, close-overflight missiles, as depicted in figure 4. the former application, which is the more traditional one, requires the formation of a single-piece efp capable of flying in a stable position to the target. this refinement has led to the flared efp rod and, more recently, to the finned efp rod designs. for the medium – or short-standoff applications, a new type of efp was developed. the need for an aerodynamic shape is not necessary for these applications because of the short distance the efp must travel, hence, the length of the rod was increased and the flared tail was eliminated from the design. in fact, some of these rods are purposely stretched beyond their breaking point and fracture into several pieces resulting in greater total length [5]. initiation point explosive charge liner (1) initial configuration (2) formation process (3) final configuration dss vol. 3, 2022, pp.1-14 3 figure 4. two modern applications of efp technology [5] 2. numerical model the numerical model for simulations are generated using ansys/autodyn software with appropriate boundary conditions and accurate geometric modeling. in order to predict behaviour of the liner, euler grid is used to design all three components: the explosive, the liner and the casing geometry. the mesh is modelled using 0.25 mm rectangular cells in both regions (the jet formation and the transition region). the free space is filled with still air with an initial density of 0.001225 mg/mm3 and internal energy of 2.06640·105 microjoules. outflow boundary condition is applied to all computational borders except the symmetry. this allows the expanding detonation products to leave the computational domain without interacting with its boundaries. figure 5. shows the initial geometry of standard efp used in numerical simulations in this paper. [6] figure 5. geometry of simulated efp [7] the initial geometry used in this investigation is shown in fig.6. the hmx was used as exp. charge material. the shaped charge liner is made of copper with different forms and casing is made of steel. it is important to mention that the configurations and materials of previously mentioned parts varies with the test cases. [8] dss vol. 3, 2022, pp.1-14 4 figure 6. efp model used in the research (autodyn) [8] 3. results and discussions in order to validate the numerical model, a series of numerical simulations have been carried out. obtained results were compared with numerical results found by hussain et al, [7] where a good agreement was observed. 3.1. metal casing in this section, the influence of the metal casing wall thickness and the influence of the metal casing material will be analyzed. initial configuration is shown in figure 5. in order to show the influence of metal (steel 4340) casing thickness on the process of penetrator formation, two numerical simulations were performed in the autodyn software. the configuration of the efp is the same in both simulations, only the thickness of the metal casing is varied. the thickness in the first simulation is 3 mm (figure 7a). in the case of the second simulation, the thickness of the metal casing is 5 mm (figure 7b). [8] figure 7. different metal casing thicknesses used in numerical simulations (solidworks) [8] figure 8 shows formed copper penetrators, as well as their velocities after 100 μs. it can be concluded that the thickness of the metal body affects the velocity of the formed penetrator thicker casing corresponds to a higher velocity of the penetrator. in the case of the first simulation, the casing thickness was 3 mm and the penetrator velocity was about 1750 m/s (figure 8 left). in the second simulation, the casing thickness was 5 mm, and the penetrator velocity was about 116 m/s higher than in the first simulation. the thicker the metal casing, around the explosive charge and the liner, the bigger the impact time of the explosive impulse and the bigger the total energy transmitted from the explosive to the liner. [8] space air copper steel hmx a) b) dss vol. 3, 2022, pp.1-14 5 figure 8. different penetrator velocities for different metal casing thicknesses (autodyn) [8] apart from the fact that body thickness has an influence on the process of penetrator formation in efp, it is important to note that the body material also has a certain influence. so another simulation was done that shows the difference between the formed penetrators in the case of a steel casing and a casing made of aluminum. namely, the geometry of the efp from figure 7a was used in the additional simulation. all the characteristics remained the same except that in the additional simulation, aluminum was used as the efp casing material instead of steel (figure 9). [8] figure 9. penetrator velocity of efp with a casing made of aluminum (autodyn) [8] in figure 9 it can be seen that the velocity of the penetrator, in the case of an aluminum casing, is about 1480 m/s. if this velocity is compared to a simulation in which the casing was made of steel, it can be concluded that in that case, the penetrator had a higher velocity, by about 270 m/s. material of higher density and higher values of yield strength increases the time of influence of the explosive impulse and increases the total energy transmitted from the explosive to the liner. [8] table 1 shows the characteristics of the materials used (steel and aluminum), as well as the difference in penetrator velocities after 100 µs (t=100 µs). [8] table 1. characteristics of materials used for efp’s casing and their influence on penetrator velocity [8] casing material density (kg/m3) tensile strength (mpa) yield strength (mpa) penetrator velocity (m/s) steel 7830 745 470 1750 aluminium 2700 305 215 1480 it is also important to note that it is not always possible to choose a material with more favorable characteristics, due to limiting factors. steel, as a material with higher density than aluminum, increases the overall system mass which can be a limiting factor. [8] 3.2. explosive charge in this part, an analysis of the influence of explosive charge type on velocity of the formed penetrator will be performed, and a comparison will be made for the following three types of explosives: hmx, tnt and comp b. in order to show the influence of the density and other characteristics of explosive charge on the process of penetrator formation, three more numerical simulations are presented below. initial configuration shown in figure 5 is retained (all measures, metal casing material – steel 4340, liner material – copper, metal casing velocity (m/s) velocity (m/s) velocity (m/s) dss vol. 3, 2022, pp.1-14 6 thickness = 3 mm, liner thickness = 2 mm); however now the explosive charge is different (everything else is identical). instead of the previously used hmx, now a tnt is used, with a lower density and therefore a lower detonation velocity (relative to hmx). [8] figure 10 shows a penetrator, initiated by tnt, moving at a velocity of about 1380 m/s. thus, the same efp configuration with different explosive charge led to the conclusion that the penetrator velocity was higher by about 370 m/s in the case when octogen (hmx) was used as the explosive charge. [8] figure 10. penetrator velocity of efp initiated by tnt, measured after 100 µs (autodyn) [8] figure 11 shows a penetrator, initiated by composition b, moving at a velocity of about 1635 m/s. the velocity of this penetrator is about 255 m/s higher than the penetrator initiated by tnt, and about 115 m/s lower than the velocity of the penetrator initiated by octogen. table 2 compares the results for 3 efp configurations with identical characteristics and different explosive charges. it can be easily seen from the table that a higher density of explosive guarantees a higher detonation velocity, and thus a higher value of the explosive impulse transmitted from the explosive to the liner. all previously mentioned penetrator velocities are measured after 100 µs from the initiation time point. [8] figure 11. penetrator velocity of efp initiated by composition b, measured after 100 µs (autodyn) [8] table 2. comparison of simulation parameters with different explosive charges [8] simulation no. exp. charge charge density (kg/m3) det. velocity (m/s) penetrator velocity (m/s) rel. diff. compared to tnt (%) 1 hmx 1890 9110 1750 26.8 2 tnt 1630 6940 1380 3 comp.b 1720 7620 1635 18.5 through the development of these projectiles, the charge with tnt itself was suppressed at the expense of more explosive mixtures with higher detonation velocities. this improvement leads to higher velocities and an increase in the slenderness of the penetrator, which increases its penetration capability. [8] velocity (m/s) velocity (m/s) dss vol. 3, 2022, pp.1-14 7 3.3. metal liner in order to show the influence of the liner material on the penetrating capability of the efp, a series of numerical simulations is presented below. the basic geometry of the efp used in the simulations is shown in figure 5. in this chapter, the material of the liner will be varied for the purpose of collecting information on the behavior of the explosive-formed penetrator depending on the liner material. copper, aluminum, tantalum and iron will be used as the liner materials. after the material, the configuration and the thickness of the liner (made of copper) will also be analyzed. [8] the first material to be used in the simulation is aluminum, the characteristics of the aluminum used in the simulation are shown in figure 12. [8] figure 12. characteristics of aluminum used in numerical simulation (autodyn) [8] aluminum is a material of relatively low density (2700 kg/m3); precisely because of its low density, the aluminum penetrator accelerates to high velocities (3500 m/s) in a short time interval. figure 13 (left) shows the velocity of the aluminum penetrator after 30 µs, and on the right after 50 µs. the velocity of the aluminum penetrator in both cases is about 3500 m/s. [8] in the figure on the right, it can be noticed that the penetrator is slowly tearing apart; the reason for that is the relatively low density of aluminum. this type of aluminum penetrator is not effective in the case of firing at targets located at a greater distance unless the thickness of the liner is increased in this case it is 2 mm, and it is constant. [8] figure 13. velocity and shape of aluminum made penetrator (autodyn); left-after 30 µs, right-after 50 µs [8] velocity (m/s) velocity (m/s) dss vol. 3, 2022, pp.1-14 8 the other material to be used in the simulation is tantalum, the characteristics of the tantalum used in the simulation are shown in figure 14. [8] figure 14. characteristics of tantalum used in numerical simulation (autodyn) [8] tantalum is a material of relatively high density (16690 kg/m3); because of its high density, tantalum penetrator hardly accelerates to high velocities, so that the penetrator remains at lower velocities during flight compared to other tested materials. [8] figure 15 shows the velocity of tantalum penetrator after 100 µs. the velocity of the penetrator is around 1125 m/s. the high density of tantalum guarantees that the penetrator barely loses its kinetic energy and is able to travel long distances. [8] figure 15. velocity and shape of tantalum made penetrator (autodyn); after 100 µs [8] the third material that was used in the simulation is iron, and the main characteristics of iron used in the simulation are shown in figure 16. [8] velocity (m/s) dss vol. 3, 2022, pp.1-14 9 figure 16. characteristics of iron used in numerical simulation (autodyn) [8] iron, with a density about 7890 kg/m3, produces a penetrator with slightly higher velocity than the one made of copper. the velocity of the penetrator is around 1882 m/s (figure 17), which is 132 m/s higher than for the copper penetrator. [8] figure 17. velocity and shape of iron made penetrator (autodyn); after 100 µs [8] penetrator velocities are presented in table 3. table 3. comparison of penetrator velocities made of different materials [8] liner material time (µs) penetrator velocity (m/s) copper 100 1750 aluminium 50 3500 detached part aluminium 100 penetrator tearing up tantalum 100 1125 iron 100 1882 velocity (m/s) dss vol. 3, 2022, pp.1-14 10 it can be noticed that there was a rupture of the aluminum penetrator; the detonation wave elongated aluminum penetrator way beyond its stretching limit due to its low density and relatively weak atomic structure. the velocity and range of the tantalum penetrator are the smallest; this penetrator suffers the greatest decrease in density, which causes an increase in its temperature. tantalum penetrator makes the largest hole (diameter) in the target (when breaking through the target, it results in a wider crater). the highest temperature occurs with tantalum penetrators which also means the creation of hot fragments on the target. due to its lower price, easy procurement and easy machining, iron is an attractive material for the production of efp liners. the copper penetrator has the greatest slenderness it is mostly used due to the greatest depth of penetration. copper and mild steel are the main materials used to make the liners in the efp configuration that provide the formation of a "solid" penetrator figure 18 (right). tantalum, aluminum and iron are preferred in efp configurations that guarantee the formation of a "hollow" penetrator figure 18 (left). [8] figure 18. hollow ef penetrator (left); solid ef penetrator (right) [9] in addition to the liner material, the liner geometry itself has a great influence on the penetrator formation process. the various liner shapes and penetrators formed from such shapes will be shown below. the dependence between the geometry of the liner and the final shape of the penetrator is very complex and has not yet been adequately described. numerical model that establishes a dependence between the finite velocity of the penetrator and the initial geometry of the liner is presented below. two different models were used, the first model implies a constant liner thickness the thickness in four configurations will vary from 5 to 14% of the explosive charge diameter. the second model implies variable liner thickness (thickness increases or decreases from the periphery to the center of the liner) as presented in table 4. copper will be used as the liner material, as an explosive charge hmx (octogen), and detonation will be performed from the point located at the rear end of the explosive charge on the axis of symmetry. [8] for a constant liner thickness of 2 mm, a numerical simulation has already been presented earlier in the paper, the velocity of the penetrator was around 1750 m/s, and the mass of the liner was around 13 g. the kinetic energy of this penetrator is around 19.93 kj, after 100 µs. [8] for a constant liner thickness of 3 mm, the liner mass is about 19.5 g and the penetrator velocity is around 1305 m/s (figure 19). the kinetic energy of this penetrator, after 100 µs is around 16.62 kj. [8] figure 19. velocity and shape of copper made penetrator (autodyn); after 100 µs (liner thickness = 3 mm) [8] velocity (m/s) dss vol. 3, 2022, pp.1-14 11 for a constant liner thickness of 4 mm, the liner mass is around 26 g and the penetrator velocity is around 1010 m/s (figure 20). the kinetic energy of this penetrator is around 13.26 kj. [8] figure 20. velocity and shape of copper made penetrator (autodyn); after 100 µs (liner thickness = 4 mm) [8] for a variable liner thickness of 2 mm in the center, and 1 mm on the periphery, the liner mass is around 9.5 g and the penetrator velocity is around 1618 m/s (figure 21). the kinetic energy of this penetrator is around 12.45 kj, after 100 µs. [8] figure 21. velocity and shape of copper made penetrator (autodyn); after 100 µs – liner thickness is variable (2 mm – center; 1 mm – periphery) [8] for a variable liner thickness of 1 mm in the center and 2 mm on the periphery, the liner mass is around 9.36 g, and the penetrator velocity after 20 µs is around 2900 m/s the penetrator front end (figure 22 left). the kinetic energy of this penetrator is not relevant because it breaks. figure 22 on the left shows the penetrator after 20 µs, while the figure on the right shows the penetrator after 30 µs. it is evident that due to the velocity gradient (the velocity of the penetrators front end is about 2900 m/s and the velocity of the tail is about 1800 m/s) the penetrator will rupture for these reasons the shaped charge jet is separated into primary and secondary jet (speaking of high-explosive anti-tank warheads). in this case, the front end of the penetrator would have the greatest impact on the penetration of the projectile the mass of the front part of the penetrator should be calculated in order to reach the actual value of kinetic energy, assuming that no subsequent rupture of the front end of the penetrator will take place. penetration rupture occurs solely due to the difference (variation) between the velocities of the front end and tail of the penetrator (velocity gradient). [8] velocity (m/s) velocity (m/s) dss vol. 3, 2022, pp.1-14 12 figure 22. velocity and shape of copper made penetrator (autodyn); after 100 µs – liner thickness is variable (1 mm – center; 2 mm – periphery) [8] in the specific case, the problem was the shape of the liner. the explosive impulse first reaches the part of the liner closest to it (the central part of the liner), accelerating the central, and in this case the thinnest part of the liner to a higher velocity than the peripheral parts. numerical simulation showed that there will be a subsequent rupture of the penetrators front end, after approximately 65 µs, as shown in figure 23. [8] figure 23. copper penetrator shape (autodyn); after 65 µs liner thickness is variable (1 mm center, 2 mm periphery) [8] table 4 presents the results of simulations where the thickness of the liner was varied to describe the behavior of the penetrator penetrator velocities were recorded after 100 µs, except for the velocity of 2900 m/s (after 20 µs). [8] table 4. different geometries of efp copper made liner [8] figure 24 shows a fully formed copper made ef penetrator after 160 µs of simulation time. the thickness of the liner was in this case 2 mm. velocity (m/s) velocity (m/s) liner configuration thickness liner mass (g) penetrator velocity (m/s) kinetic energy (kj) front end dss vol. 3, 2022, pp.1-14 13 figure 24. fully formed copper penetrator, after 160 µs (autodyn) [8] 4. conclusions based on theoretical considerations and analysis of available numerical model (presented in [7]) for predicting the shape, velocity, pressure distribution, density and kinetic energy of explosively formed penetrator, a numerical model was created in autodyn (ansys) software. the data obtained from ref. [7] (all data obtained by numerical model presented in [7] is compared to the data obtained from experiment, and good agreement was achieved), and the data obtained by numerical simulation presented in this paper were compared. the following can be said: 1. the penetrator velocities (provided with the model from [7]) have a satisfactory agreement with the penetrator velocities from numerical model presented in this paper. the largest difference between the values is 4.12%. maximum deviations occur when the penetrator reaches a stable velocity (while the minimum deviations occur between 10 and 40 µs – depends on the liner material). 2. the presented numerical model gives useful results, the values of the penetrator velocity and shape. good agreement between the results of the numerical model and experiment data indicates that the initial and boundary conditions are well set. 3. the advantage of the numerical model is that it allows the calculation of penetrators parameters based on varying the geometric, material and other characteristics of the liner, explosive and metal casing – performing relatively low-cost analysis. 4. the accuracy of the numerical model depends on the mesh, initial and boundary conditions. the accuracy of the numerical model can be increased by modifying the mesh (i.e. by increasing the number of finite elements). declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] s. m. zakir, l. yulong, a. sohail, "numerical study on the optimum design of explosively formed projectile", 15th international bhurban conference on applied sciences and technology (ibcast), 2018. [2] alan catovic, anti-tank projectiles (lectures), mechanical engineering faculty, sarajevo, 2020. dss vol. 3, 2022, pp.1-14 14 [3] https://fas.org/man/dod-101/navy/docs/es310/ballstic/ballstic.htm, [4] a. stamatovic, projectile construction, belgrade, 1995. [5] j. carleone, tactical missile warheads, washington dc, 1993. [6] h. kemmoukhe, s. savić, s. terzic, m. lisov, n. rezgui, h. sedra, "improvement of the shaped charge jet penetration capability by modifying the liner form using autodyn-2d", belgrade, october 2018. [7] g. hussain, a. hameed, j.g. hetherington, a.q. malik, k. sanaullah, "analytical performance study of explosively formed projectiles", journal of applied mechanics and technical physics, january, 2013. [8] m. salkicevic, explosively formed projectiles, master thesis, university of sarajevo, mechanical engineering faculty, defense technologies department, june 2021. [9] f. rondot, "terminal ballistics of efps – a numerical comparative study between hollow and solid simulants 19th international symposium of ballistics, interlaken, switzerland, 7–11 may 2001. microsoft word 22-31_187 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.22-31 https://doi.org/10.37868/dss.v3.id187 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 22 minimum viable product: a robot solution to eod operations hamza bećirspahić1*, haris basarić2, tarik namas3, benjamin duraković4 1 mechanical engineering department, international university of sarajevo, bosnia 2,3 electrical and electronics engineering department, international university of sarajevo, bosnia 4 faculty of engineering and natural sciences, international university of sarajevo, bosnia *corresponding author e-mail: hamzabecirspahic@gmail.com received: feb. 27, 2022 revised: jun. 19, 2022 accepted: jun. 28, 2022 online: jul. 2, 2022 abstract this paper presents the design and development of an eod robot, with mvp characteristics. the design is based on a solid base structure with an arm manipulator attached to the base. the overall dimensions of the robot are 590x860x340 mm and it weighs 55 kg. the robot is capable of towing heavy objects as well as lifting sensitive objects. the robot has a maximum horizontal reach of 1400 mm and a vertical of 1200 mm. the robot is tested according to guidelines developed in the usa, as much as the conditions allowed. briefly, the results can be summarized as follows: the setup time for the robot is 10 minutes, it can reach speeds up to 8 km/h, it has a towing capacity of 40 kg and the maximum communication reach is 20 m. among successful tests, the weaknesses were also found which act as a guide for future designs and developments. these weaknesses are what mvp concepts are actually developed for. © the author 2022. published by arda. keywords: explosive ordnance disposal, eod robot, ordnance, robot testing, minimum viable product, mvp 1. introduction landmine and cluster munition monitor reported that around 26 states and 3 other areas are contaminated by cluster munition remnants, as of august 2021 [1]. cluster munition remnants are defined, by the convention on cluster munition, as conventional munition designed to disperse explosive submunitions, weighing less than 20 kg and including that submunition, that failed to detonate [2]. it is very easy to conclude that the impact is still widely present and it is being addressed by many organizations, international as well as national. in bosnia and herzegovina, among the countries most hit by cluster munition and landmine contamination, the problem is still being addressed, as the country asked for an extension of the deadline for clearance in 2021 and expects clearance to be completed by late 2022 [1]. there is one more problem the authors found. the defense industry companies, locally, are testing explosives at their premises, and after unsuccessful testing usually the human operator dismantles the explosive by hand which can lead to severe injuries, not uncommon to occur in these companies. this and the facts mentioned in the first paragraph are what inspired and motivated the authors to try to contribute to a solution. the solution, as seen by the authors, is a remotely controlled robot that is equipped with a manipulator and a gripper and capable of handling operations that are required in an explosive ordnance disposal (eod). since eod robots are readily available on the market, some of the most popular are presented in table 1. dss vol. 3, 2022, pp.22-31 23 table 1. eod robots available on the market company model max. lift capacity weight reach (forward) speed reference 1. telerob, germany teodor evo 100 kg 383 kg 1860 mm 3 km/h [3] 2. northrop grumman, u.s.a. andros f6a 61 kg 220 kg 1440 mm 4.8 km/h [4] 3. qinetiq inc., u.s.a. talon 68 kg 81 kg 1570 mm n/a [5] 4. l3harris technologies, u.s.a. t7 113+ kg 322 kg 2200 mm 8+ km/h [6] 5. superdroid robots, u.s.a. lt2-f “bulldog” 7+ kg full extension 40 kg 1220 mm 2 km/h [7] 6. superdroid robots, u.s.a. hd2-s “mastiff” 9+ kg full extension 68 kg heaviest configuration 890 mm 2 km/h [8] 7. nic instruments ltd., united kingdom zeus 15 kg 51.7 kg 1460 mm 3 km/h [9] teodor evo is an eod robot developed by telerob company. the robot is capable of performing not just eod operations but also cbrn operations, which stands for chemical, biological, radiological and nuclear threats. it is equipped with a 6 degrees-of-freedom manipulator and an onboard tool magazine for convenient remote tool change. it has intuitive control handling and it is very popular with military and law enforcement agencies [3]. andros f6a is an eod robot developed by a subsidiary company of northrop grumman, remotec inc. it is distinguished by the capability to pneumatically release its wheels for width reduction when applications demand it. it is equipped with a 7 degrees-of-freedom manipulator and capable of 3-4 hours on mission operations [4]. talon robots are eod robots developed by qinetiq inc. they are in active service since 2000s when they were used in bosnia and herzegovina for the disposal of live explosives. talon robots are also one of the lightest robots on the market that are equipped with multiple degrees-of-freedom manipulators. it can also be equipped with multiple cameras with the option to be mounted with thermal cameras as well. the advantage of talon certainly is the number of options that the controller comes with, for example, it comes as lcu, meaning laptop control unit, as well as trc, tactical robot controller [5]. t7 is a heavy-duty robot developed by l3harris technologies in the united states. it is designed to assist not exclusively eod operations but also hazmat, meaning hazardous materials cleanup, intelligence and surveillance operations as well. it can be mounted with many different tools such as a disruptor, which blasts pressurized water to neutralize the threat on-site, a forklift and many different sensors such as the sensors for cbrn operations. one of the most significant characteristics of this robot is certainly the haptics control it utilizes. haptics provide the operator with the sense of touch and proximity, almost as good as a bare hand can provide [6]. superdroid robots company manufactures the model lt2-f, commonly known by the name “bulldog”. this model comes in many different configurations. it can be equipped with a 4-axis or a 6-axis arm manipulator, that can be equipped with wire cutters, different sensors for different applications. the arm manipulator can dss vol. 3, 2022, pp.22-31 24 be shortened or removed as well to aid in low clearance areas. as previously listed models it can be applied in many different scenarios, ranging from eod to remote surveillance and building cleanups [7]. hd2-s also known as the “mastiff” is another model manufactured by superdroid robots. this model is a bit bulkier model compared to lt2-f model. it as well comes in different configurations and can be equipped with wire cutters and application dependent sensors. capable of staying operational up to 8 hours [8]. zeus eod robot is developed by nic instruments ltd. it is a very reliable product that utilizes a very effective communication type, an fsk, meaning frequency shifting keying, which is a communication type that employs alternating frequencies used in communication to avoid any noise disturbances. it is equipped with a battery capable of operating from 2-4 hours, mission dependent. it comes in different configuration with different arm sections, meaning different degrees-of-freedom manipulators [9]. the preferred communication in unmanned vehicles utilizes the ems (electromagnetic spectrum), between operator unit and robot, because it ensures a long range of operation. the waveforms of the communication are encrypted, especially when used in military applications [10]. sometimes ems is not applicable, because of strong interferences or large pieces of metal, which disrupt the signal. in those instances, some manufacturers provide a cable connection, which can reach up to 200 m, ideally a fiber optic cable [9]. the pricing of these robots is not readily available on the official websites of the companies. an interesting article, which presents cost-wise accessible eod solutions, states that the range of prices for commercial robots, such as the ones presented in table 1., is from $40 000 to $150 000 [11]. the purpose of this paper is to design a minimum viable product for eod operations. an iterative designbuild-test cycle is performed with the aim of developing a low-cost optimal physical platform for eod robot in the category. the configuration test purpose is to quantitatively evaluate the packaging and setup tools used to start up the robot. the goal is to come up with metrics about the weight of packaging, setup time from configuration to deployment, weights of the control unit and the tools needed for repair. particularly, the following objectives are achieved: physical design and development, mobility test on a flat paved terrain, mobility test with towing capacity, radio communications test by establishing a line of sight, manipulation test grasping dexterity and robot configuration for logistics tests. 2. methods the design of an eod robot proposed by the authors was inspired by the robots readily available on the market. the base structure of the robot is made from steel bars, roughly 25 cm2 in cross-section area. the bars are welded together to form a structure that consists of two rectangles connected by bars with an angle, as seen from the side. the rectangle closer to ground level is reinforced by bars welded to form a cross like symbol. four dc motors are used to power mobility and they are welded on to the lower rectangle, with steel axels welded on them and to the wheels. the wheels are standard inflatable rubber wheels that come from small garden carts. the manipulator is made of three steel bar segments. the first segment is welded to the bottom of the base structure at its middle and extends some 50 cm from the weld. the second segment is welded to a door hinge which is welded to the first segment and the same procedure is applied to the third segment as well. the gripper is positioned at the end of the third segment and is made from aluminum. it is manufactured on a cnc machine and coated in plastics on the inside to secure maximum gripping. the manipulation of the arm is made possible by three linear electrical actuators which can lift weights up to 100 kg, respectively. the actuators are fastened to the segments of the arm manipulator by screws and nuts. the whole base structure is enclosed by plywood pieces and inside is the „brain“ of the robot. electronically, the robot is manipulated by simple relays which are powered through a car battery of 12 v. the opening and closing of switches, depending on the operation that needs to be applied, and the relays is controlled by raspberry pi which is powered by a power bank. the underlying circuit is called an h bridge. the communication with the robot is established through the wireless network connection that raspberry pi emits. the final design elaborated is presented in figure 1. followed by table 2. where the components used in the manufacturing are briefly presented. dss vol. 3, 2022, pp.22-31 25 as the title of this paper suggests, the authors presents a minimum viable product (mvp), described as: “a version of a new product that allows a team to collect the maximum amount of validated learning about the customers with the least amount of effort “, by eric ries, founder of lean startup methodology [12]. figure 1. design of the robot table 2. list of components built in physical steel platform number. component specifications quantity 1. motor 12v high torque motors 4 2. wheel 20 cm diameter wheel 4 3. relay 5v 8 channel output relay board, maximum current 10a 2 4. raspberry pi raspberry pi model 4 1 5. battery 12v car battery 1 6. actuator linear electric actuator 12v, maximum load capacity 100 kg 3 7. power bank 5v dc power bank 1 it is important to emphasize the viable part of the name as well as the minimum part and not fall into the trap of favoring one over another [13]. in other words, the product has to satisfy the functionality requirements. the authors do emphasize that their design is not fully functional as compared to the robots listed in table 1. in the introduction. the department of homeland security of u.s.a. alongside with the national institute of standards and technology wrote a guide on the topic of testing and validating performance indicators of response robots, which include robots applied in dismantling explosive devices, searching for survivors in collapsed structures, investigating of illicit border tunnels and many more fields of application [14]. under the sponsorship of department of homeland security, the response robots undergo real-life scenarios which can include navigating through the test site and execution of different tasks such as: climbing stairs, handling of objects with manipulators, testing of communication range and many more [14]. the tests performed in this research are: logistics robot test configuration, mobility on a flat paved terrain, mobility with towing capacity, radio communications establishing a line of sight, manipulationgrasping dexterity [14]. the mobility on a flat paved surface evaluates the speed of the robot. it is done by navigating the robot between two pylons 50 m apart. average time is calculated from 10 repetitions. mobility with towing capacity evaluates the maximum capacity the robot can tow on a flat paved surface. average time for 10 repetitions is used as a metric. radio communications test method establishes a line of sight which is the maximum downrange distance at which the robot completes the tasks to verify the functionality of control, video, audio dss vol. 3, 2022, pp.22-31 26 and sensing mechanisms. manipulation evaluates the grasping dexterity of the arm manipulator. it is measured by the number of pick-and-place operations a robot can complete in as little time possible. in addition to tests elaborated above, energy consumption of the robot is also measured. it is evaluated using a multimeter, which measures how much current is drawn by actuators under specified load application. 3. results and discussion as a result of the methods used in the construction of the robot, the basic specifications of the robot are presented next. the robot`s base structure is roughly 590 mm in width, measurement which includes wheels, 820 mm in depth, measured from the center of the wheels and 340 mm in height, measured from the ground up. the arm manipulator has a maximum reach of roughly 1400 mm in horizontal direction and a maximum reach of 1200 mm in the vertical direction. the overall weight of the robot is roughly 55 kg, which includes all inside components. the dimensions are displayed in figure 2. figure 2. dimensional sketch of the robot the robot`s functionality is measured according to the guidelines presented in the methods section. the guideline was written by the department of homeland security with its associates. the authors specifically chose applicable tests from the guideline such as setup time, speed test, mobility with towing capacity, radio communication test, object manipulation and lifting capacity. the test results are briefly presented in table 3. table 3. test results setup time speed mobility with towing capacity flat paved surface mobility radio communication test manipulation of objects lifting capacity 10 min up to 8km/h 40 kg 10 repetitions in 10 min 20 m line-ofsight 3 objects per 10 min at full extension 15 kg the first test conducted is the robot test configuration which measures the setup time of the robot and its equipment. the authors also took into consideration the transport of the robot using an automobile. since the height of the arm, when all the actuators are in the fully retracted position, prevents the robot to fit into an average size automobile, a necessary measure is to dismantle the actuator, stemming from the base of the robot to the arm, to be able to fit the robot into the automobile. this increases the setup time which amounts to 10 minutes and includes: extracting the robot from the car, connecting the actuator that was dismantled previously, connecting the power wires to the car battery, connecting the power bank to the raspberry pi and finally connecting the laptop to the wi-fi connection of the raspberry pi. the most time-consuming setup dss vol. 3, 2022, pp.22-31 27 process is surely the connection of the actuator which requires the use of ordinary plyers and a size 13 wrench. to conclude the results, setup time amounts to 10 minutes, with the weight of the equipment of 4 kg (laptop as the control unit, plyers and a wrench, additional wiring for repair). the second test conducted is the „speed test“. according to authors measuring, the robot can achieve speeds up to 8 km/h, which is competitive enough. the authors note that the robot does not possess speed control, since the dc motors are taken form windshield car wipers and are programmed to utilize one speed of motion. on the bright side, these dc motors can generate around 30 nm of torque, well enough to power the robot. mobility with towing capacity is the test that the authors conducted inside the laboratory where the robot is constructed. the maximum tow value tested is 40 kg. the robot`s capability of towing motion was also successfully tested with the towing of a wheeled chair with a person sitting on the chair. although the chair is wheeled, this test proves that the robot has substantial towing capacity. radio communications test, testes the capability of the robot to continue working and receiving signals from the control unit far away from it. this test is probably the weakest point of the robot, since the communication with the robot is achieved through wi-fi signal of the raspberry pi. the furthest distance away from the control unit, at which the communication still operates without interferences is roughly around 20 m. this distance is further lowered with the introduction of obstacles such as walls. this weak point is surely something the authors are working to improve. manipulation of objects is a test which measures the capability of the robot to pick-and-place as many objects in as little time possible. the authors do mention here that the gripper is designed in a such a way, that the objects need to be gripped with the very tip of the gripper in order to lift them. this especially applies to thin objects such as bottles, which would otherwise fall through the gripper because of the width of the gripper at its middle. the authors manipulated objects such as bottles, desk chairs, bricks, metal objects etc. one of the disadvantages of the gripping of the robot is the fact that the whole robot needs to be moved in order to place the end of the gripper in the position to grab an object. this is due to the fact that the arm can only be manipulated in the vertical direction. to conclude, due to the limitations in the mobility of the arm, the robot can pick-and-place only 3 objects in the time span of 10 minutes. in addition to these tests, a diagram of the lifting capacity of the robot is presented in figure 3. below. the outer circle presents the lifting capacity at maximum extension and the inner circle represents the lifting capacity at full retraction. these values can be narrowed down to a single value because the lifting is executed only using one actuator at a time. here the values differ only because of the fact that the arm is loosely constructed and is not capable of handling higher loads at full extension. figure 3. lifting capacity in relation to reach dss vol. 3, 2022, pp.22-31 28 further tests are related to energy consumption also related to the lifting capacity. the relationship between current consumption and lifting capacity is shown in figure 4. figure 4. current consumption vs. load values figure 4. shows current consumption on different loads expressed in kg that is needed for actuator. it can be seen that the relationship is almost linear. also considering manufacturer’s datasheets it should be indeed linear. peak current consumption is 2.3 2.5 a for the 20 kg load with 12 v source configuration. for loads less than 6 kg energy consumption is 1 a or less. power-vise 30 w of power is used at peak. measurement is done by using a multimeter device (also can be done using amperemeter or oscilloscope). actuators are connected in series and tested for various loads with constant 12 v voltage supply. figure 5. below shows how speed of the motor is slowly decreasing when the load is increased. the relationship is also linear. figure 5. speed vs. load values value drops slightly from 28 mm/s for load <2 kg to around 25.6 mm/s for the 20 kg load. first measurement experiment is done using timer and measuring tape. time is measured for 5 seconds with exact starting point after which distance is measured after timer is stopped. this measurement was repeated several times. second technique was directly programming actuators to be switched for exact amount of time controlled by main controller. this gives exact and more precise time of 5 s. dss vol. 3, 2022, pp.22-31 29 based on the test result obtained in this research, a comparative analysis is done and the results are listed in table 4. table 4 in this research briefly presents the comparative advantages and disadvantages of authors eod robot to the robots availaible from table 1. in the introduction section. in a nutshell, authors robot is lower in performance features compared to models teodor evo and model t7, which mainly reflects in lower weight and lifting capabilities. on the other hand, lower cost presents an important advantage compared to these two models. competitive performances can also be observed compared to models zeus, hd2-s, lt2-f, andros f6a. these are mainly in regards to reach and lifting capacity. a significant advantage in lifting capacity, speed and reach potential performances are achieved compared to models hd2-s, lt2-f and andros f6a. to summarize, authors eod robot has a high potential to compete against the models already available on the market. table 4. comparative results model specification this eod robot this eod robot max. lift capacity: 20 kg weight: 55 kg reach (forward): 1400 mm speed: up to 8 km/h  competitive in category teodor evo [3] max. lift capacity: 100 kg weight: 383 kg reach (forward): 1860 mm speed: 3 km/h  lower category  lower performances  lower cost as an advantage andros f6a [4] max. lift capacity: 61 kg weight: 220 kg reach (forward): 1440 mm speed: 4.8 km/h  same category  competitive reach potential  higher speed of mobility  lower overall weight talon [5] max. lift capacity: 68 kg weight: 81 kg reach (forward): 1570 mm speed:  same category  lower lifting capacity t7 [6] max. lift capacity: 113+ kg weight: 322 kg reach (forward): 2200 mm speed: 8+ km/h  lower category  significantly lower lifting capacity  lower reach lt2-f “bulldog” [7] max. lift capacity: 7+ kg full extension weight: 40 kg reach (forward): 1220 mm speed: 2 km/h  same category  significantly higher lift capacity  competitive performances per each parameter  lower cost as an advantage hd2-s “mastiff” [8] max. lift capacity: 9+ kg full extension weight: 68 kg, with the heaviest configuration reach (forward): 890 mm speed: 2 km/h  significantly higher reach potential  higher speed of mobility  competitive overall weight  higher lifting capacity at full extension zeus [9] max. lift capacity: 15 kg weight: 51.7 kg reach (forward): 1460 mm speed: 3 km/h  same category  higher overall weight  competitive reach potential  competitive lift capacity dss vol. 3, 2022, pp.22-31 30 4. conclusion this paper presents the design and development of an mvp eod robot, specifically designed to operate with explosive devices in their removal, disposal and neutralization. this mvp design is functionality-wise limited, due to budget limitations, but nevertheless, presents a solid opportunity for testing and presentation purposes. the final design is 590x820x340 mm in dimensions, weighs 55 kg with a maximum manipulator reach of 1400 mm. the vertical reach is 1200 mm. the setup time of the robot with all of its configurations is 10 minutes, and the equipment weighs 4 kg which includes a laptop, as a control unit, plyers, a wrench and some additional wiring for repairs. compared to models from table 1. authors robot lacks a control unit which is highly durable and easily carried. other equipment is carried independently and also lacks a custom-made bag. the setup time is mostly slowed because of the fact that the manipulator must be partially dismantled to fit into an average size car. models from table 1. usually come with a modular manipulator and other accessories which are easily mounted on the robot. slower setup time is also due to the fact that the raspberry pi needs to be manually turned on with a power cable and the program needs to be compiled each time the session is ended. fortunately, these specifications are easily made easier and improved. the robot can reach a speed of 8 km/h due to its high torque dc motors. the towing capacity is roughly 40 kg, which highly depends on the surface of the motion. the weakest point in the design is the communication reach, which is limited by wi-fi signal, to 20 m. the second weakest point is the gripping, which needs to be very precise, especially for thin, narrow objects, such as bottles. compared to the robots from table 1, this low-cost eod robot platform represents a solid foundation into further design and development endeavors, which will hopefully take place in the near future. the plan for future work is to upgrade the existing physical platform to an autonomous eod robot with the ability to detect explosive devices and mark them or safely dispose of them. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] “cluster munition monitor 2021”, reports, http://www.the-monitor.org/en-gb/reports/2021/clustermunition-monitor-2021.aspx (accessed apr. 10, 2022). [2] o. english and f. spanish, “diplomatic conference for the adoption of a convention on cluster munitions convention on cluster munitions,” 2008. [3] “teodor evo.” https://www.telerob.com/en/products/teodor-evo (accessed apr. 11, 2022). [4] “home northrop grumman.” https://www.northropgrumman.com/ (accessed apr. 11, 2022). [5] “bomb disposal robot qinetiq.” https://www.qinetiq.com/en-us/capabilities/robotics-andautonomy/talon-medium-sized-tactical-robot (accessed apr. 11, 2022). [6] h. technologies, “ruggedized robot for military, police, and hazardous missions,” 2020. [7] “lt2-f bulldog lightweight tactical support robot by superdroid robots.” https://www.sdrtactical.com/robots/sdrt_bulldog.php (accessed apr. 18, 2022). [8] “hd2-s mastiff heavy-duty support robot by superdroid robots.” https://www.sdrtactical.com/robots/sdrt_mastiff.php (accessed apr. 18, 2022). [9] “zeus bomb disposal robot manufacture & supply | nic instruments.” https://www.nicltd.co.uk/zeus-ultimate-modular-unmanned-ground-vehicle/ (accessed apr. 18, 2022). [10] “unmanned systems integrated roadmap unt digital library.” https://digital.library.unt.edu/ark:/67531/metadc949794/ (accessed apr. 18, 2022). [11] t. andrew czop, k. hacker, j. murphy, t. zimmerman, a. czop, and t. zimmerman titan, “lowcost explosive ordnance disposal robot using off-the-shelf parts,” https://doi.org/10.1117/12.602526, vol. 5804, no. 27, pp. 130–140, may 2005, doi: 10.1117/12.602526. [12] “minimum viable product what is a mvp and why is it important?” https://www.productplan.com/glossary/minimum-viable-product/ (accessed may 08, 2022). dss vol. 3, 2022, pp.22-31 31 [13] “what is a minimum viable product (mvp)?”, agile alliance. https://www.agilealliance.org/glossary/mvp/#q=~(infinite~false~filters~(tags~(~’mvp))~searchterm~ ’~sort~false~sortdirection~’asc~page~1) (accessed may 08, 2022). [14] “department of homeland security response robot performance standards”, nist, https://www.nist.gov/programs-projects/department-homeland-security-response-robot-performancestandards (accessed may 08, 2022). microsoft word 53-62_168.docx defense and vol. 2, may 2 https://doi.org this work is lice to share and ada authorship and in analysis systems roman km faculty of secu *correspond © the auth 2021. published by arda. 1. introdu crime is on environment frequency o know the cri of crime in t brings to th cognitive m authors state by administr with it. arr visualization the study cl organizing value model premise are significant in burglary sus sake of futu voivodeship the tools p resources in public aware them-the cha presented in baseline stud successfully the analysis d security s 2021, pp.53-62 g/10.37868/ds nsed under a cre apt the material nitial publication s of curr met* urity engineerin ding author: ro hor y uction ne of the asp t [1]. the se f recorded c iminal situat the 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s e d s y. fn h 7 e e n d. d g g h e d dss vol. 2, may 2021, pp.53-62 54 2. analysis of current practical solutions the crime map is currently a commonly used tool by public authorities, primarily intended for the population, but also security forces and services, to increase the sense of security of the population [9]. within the selected region, certain crime indicators are presented, which are filtered by the users of this map based on selected criteria. in this case, we can talk about the functionalities, depending on the crime indicators that individual crime maps offer. based on their comparison, it can be stated that some crime maps represent a greater added value, whether for the police, local governments or residents. 2.1. case of the slovak republic in 2013, the ministry of the interior of the slovak republic published a map of criminal offenses in sr (figure 1). the map shows the number of crimes in individual police districts with a percentage of clarified crimes [10]. the information is freely available to the general public (residents), who can choose either general crime or a certain type of crime (economic, property, moral, violent) for a certain period (quarter, halfyear or year) [11]. figure 1. map of crimes in slovakia, the year 2020 [10] however, this map brings with it some shortcomings that can distort the real state of crime. first, we can mention the fact that the map works with absolute and not relative data [12]. this means that the crime map shows the overall status and not the level of crime, which results in the absence of a crime rate. the map has up to 12 categories of crimes, each with a different color. clarification rate is expressed as a percentage rounded once to two decimal places and once to six. somewhere the character "%" is listed and somewhere it is missing. based on these facts, the map can have a misleading, chaotic and confusing impression [11]. 2.2. case of the czech republic the primary reason for the creation of this application was the need to share the content of information processed by the police of cz to locate crimes and administrative offenses with the public and selfgovernment entities in cz. the application thus combines in one place information on the occurrence of offenses registered by the police of cz so as not to violate the personal data protection of victims, their secondary victimization as well as violation of personal data protection of persons suspected of committing a crime [13]. dss vol. 2, may 2021, pp.53-62 55 the application contains basic data on administrative offenses and selected types of crimes that were reported by the police of cz in the selected period or which were registered by the police of cz through its activities (figure 2). at the same time, only data containing location information is displayed (display of data from 2013). the application displays those types of crime in which the disclosure may be preventive and their disclosure does not hinder the tactical aspect. the type is e.g., property, violent crime, extremism, drug crime, etc. in the case of administrative offenses, the scope of the data is not limited in this way [13]. in the application, any user can view or export spatial data on the occurrence of offenses registered by the police of cz for the territory of cz or individual municipalities in the territory of cz. this information may be further shared or used following the license for the creation of other technical means intended for crime prevention in cz [13]. figure 2. display of the crime of the ostrava police district [13] the primary reason for the application was the need to share the content of information managed by the police of cz to locate crimes and administrative offenses with local government entities (with a focus on municipalities) in cz. in this case, local governments, with a focus on municipalities, are considered to be an authorized user who has access to the basic functionality intended for the receipt, evaluation, analysis and sharing of published data, not only by the police of cz [13]. the content cards also include clear statistics within the territorial division of the municipality (figure 3), optimization of the map for the selected location, insertion or user overview of individual offenses within the scope of the municipality and others [13]. figure 3. composition of criminal activity within a specific municipality of cz [adopted from 13] 0 0 15 0 4 31 2 15 7 0 16 0 5 10 15 20 25 30 35 extremism weapon addiction traffic accident generally dangerous property others fraud theft burglary fire, explosion violence composition of criminal activity in the municipality dss vol. 2, may 2021, pp.53-62 56 2.3. case of united kingdom the crime map website displays open data on crime and policing in england, wales and northern ireland (figure 4). the user is provided with data on crime, individual police forces or neighborhood patrols through an interactive map. furthermore, you can easily download this data in csv format to your pc [14]. there is also room to download data on police activities over a period and a range of other data related to police activities, including the apprehension of the perpetrator or the processing of emergency calls. all information on this website is made available under the open government license [14]. figure 4. crime in the city of london [14] the data displayed by the web application provides a complete overview of crime level overview (figure 5), type of crimes (figure 6), the results of criminal proceedings and data on reports or searches that are statistically reported for a specific period. published statistics are updated monthly, with the possibility of downloading data from the archive from 2013 [14]. figure 5. display of the seasonal state of the crime of the examined locality [14] figure 6. display of the number of selected types of crimes of the locality [14] dss vol. 2, may 2021, pp.53-62 57 2.4. case of germany the crime map shows brief information on the crimes, perpetrators and victims available for each region of the sixteen länder of germany (figure 7). each region is assigned a specific color, which provides an initial indication of the crime rate per 100,000 inhabitants, with the rule that the darker the color, the greater the crime burden. within the structure of crime, selected types of crime are statistically processed, such as murder and homicide, rape and sexual assault, robbery, motor vehicle theft, drug offenses and others [15]. figure 7. interactive map of germany initial display of crime rate [15] after selecting a specific area in the interactive map or the appropriate coat of arms of a specific area, the system generates a pdf document [15] that contains statistically processed data, presented in the form of graphs (figure 8, 9) and tables (table 1). table 1. development of the number of crimes and their clear-up rate in the bavaria region [adopted from 15] year crime total clear-up rate [%] registered explained 2013 635 131 406 873 64,1 2014 650 868 419 482 64,4 2015 805 915 584 128 72,5 2016 882 473 581 860 65,9 2017 629 512 420 440 66,8 dss vol. 2, may 2021, pp.53-62 58 figure 8. graph of percentage distribution of crime in the bavaria region by age in 2017 [adopted from 15] figure 9. graph of crime development by nationality of the offender region of bavaria [adopted from 15] 2.5. case of the united states of america a project to map crime in us was developed to help police and law enforcement reduce the level of crime. through better information of the population about the current state of crime in the vicinity of their residence, there is a subjective perception of crime, which can reflect the real values of crime. this fact represents the creation of greater self-confidence among the inhabitants of one defined area, who can help reduce the level of crime by their activity [16]. crime data are obtained at regular intervals from the registration system of individual police departments, which results in the possibility of displaying the most currently available data. the extraction, processing and presentation of data are preceded by their verification, while they are generalized by blocking to ensure their protection and at the same time, they cannot be misused [16]. the interactive map offers a series of search criteria, which are used to specify the search for specific incidents of the defined space for the selected period (figure 10) [16]. figure 10. showing specific incidents in oakland, california from 01/04/2021 to 01/31/2021 [15] 3% 8% 11% 78% percentage distribution of crime by age child (up to 14 years old) minor (14 18 years old) mladistvý (18 21 years old) adult (21 years and older) 198240 189090 179802 180344 173401 91569 113896 281500 266089 129401 0 100000 200000 300000 400000 500000 2013 2014 2015 2016 2017 development of crime according to the nationality of the offender german other the presenta selection of tabular outp department, different typ figure 11 the statistic as pdf docu 2.6. case of the crimina provided by recorded und criminal bur population o the portal th  disp  the crim  the f  depi  com  disp figure 12. g ation of the criteria usin put, it is poss date and ti pes of inciden 1. daily summ cally processe uments with f italy al burden of t y the depart der the autho rden is expr of the examin hus enables t play and com ranking of p me, first 10 provi iction of a sp mparison of se play of provin graph of com results of th ng a filter, th sible to mon ime of the nts (figure 1 mary of incid ed data in th the subseque the populatio tment of pub ority of the ressed utilizi ned region (p the display o mparison of 1 provinces ac inces with th pecific provin elected provi nces in the fo mparison of s 100 e state of the he result of w nitor the type incident. gr 1). dents from th he form of di ent possibilit on in italy is blic security state, prison ng a crime province) [17 f various sta 8 types of cr cording to th he highest nu nce in the ov inces (figure orm of an int specific prov 0 thousand in 59 e crime of th which is the e and descrip raphic outpu he city of oa isplayed inci ty of printing made availa y of the mi n, city, borde rate, which 7]. atistical outpu rimes, the overall c umber of crim verall ranking e 12). teractive map vinces in term nhabitants) [a he selected a generation o ption of the uts present t akland, calif dents can be g. able to the pu nistry of the er police, arm represents th uts, relative d crime rate or mes, g or for a spe p (figure 13) ms of individ adopted from dss v area and peri of clear table incident, des the structure fornia, over ti e saved by th ublic by the l e interior, w my and coast he number o data, such as r the crime r ecific type of ) [17]. dual types of m 17] vol. 2, may 2 iod is condit es and graph scriptive num e of crime c ime [adopted he resident in lab24 portal which reflect t guard. the of crimes co s: rate of a spe f crime, crime in 201 2021, pp.53-62 tioned by the s. within the mber, distric composed o d from 15] n their device l. it uses data ts the crime e value of the ommitted pe ecific type o 19 (value per 2 e e ct f e a s e r f r a 3. compa as crime ha criminalistic that opens t developed co the presente the degree detail of the the followin functionali clear-up rat point repres of crimes crime rate ( area) crime rate ( crime) crime rate ( over time) assessed are comparison assessed are figure 1 arison of cri as an interdis cs, juridical the door to t ountries [19] ed crime ma of objectivit data, the deg ng table 2 sh ities te sentation (assessed (type of (trends ea n of eas 3. interactiv me map fun sciplinary ch sciences, pe the creation ]. aps differ dep ty of the pre gree of updat hows the fun table 2. fu sk district p e map showi nctionalities haracter, it is dagogy, soc of geograph pending on t sented data, ting or the in nctions offere unctionality c cz police distric department 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and in this case, i me mapping el of crime minally respo 61 uk h / month a year / tation of stat pective user as well as th overnment e ter, it deals gy, but also mapping info nding on the nteractivity o t out the dive e data in the displaying a ed region, lo ly used indic r of the crim criminal sta search criteri outputs in the rime rate, wh r self-govern the form of a the criminal e and targete that it is rela g of the gdp ty of the stud from the rea ermine how . s the display gional (area, facts describ effective the cs by the rele rupts the har thus society is significant g. if the fina through the onsible inhab k / half / year y tistically pro through sele heir contribu entities or inh with many geography. i ormation sys e offered fun of the maps. ersity in the p e form of th crime rate ( ocality, conve cator of the c me map, the tus. in this c ia, such as c e form of va hile it is poss nment entitie a point displ map of the ed security m atively quest pr. the risk dy area. thes al estate cad and who wil y of the area county), loc bed above, it e security me evant police rmonious dev as a whole [ tly influence al user is an e crime rate, bitants of the dss v de year d ocessed crim ected functio ution to pract habitant). experts in t it is this aspe stems availab ctionalities, w presentation he number o crime assess erted to n in rime level of e display of case, italy m lear-up rate, arious tables sible to mon es, the crime ay of the cri cz police. t measures. tionable whe of secondar se are small m aster, person ll be respons a under cons cal (district, t can be assu easures imple departments velopment of 18]. ed by the data inhabitant o , which is b e surveyed ar vol. 2, may 2 us day / period me data can b onalities offe tice, in this c the field of ect of securi ble to sever which reflec of the result of detected c sment), whic nhabitants (n f a certain ar the crime ra may be at the number of c , graphs and nitor its time e map should imes of the s the result of ether the exac ry victimizat municipalitie nal data can sible for the sideration. a city) or sub umed that th emented. in s are very im f society and a that are dis of the survey based on th rea, multipli 2021, pp.53-62 ita month / year be a series o ered by crime case, depend criminology ity that open ral developed ct the level o ting values o rimes (crime ch shows the n = 1 000, 10 rea [20]. ate has more e head of the crimes, type d figures. we developmen d support the selected area f this display ct location o ion increase es or isolated be displayed protection o as part of the local (urban e smaller the this case, the mportant. d reduces the splayed using yed area, the e number o ed by 10,000 2 f e s y, s d f f e e 0 e e s e nt e a. y f s d d f e n e e e g e f 0 dss vol. 2, may 2021, pp.53-62 62 or 100,000 [21]. the inhabitant can thus find out the level of crime in the space of which he is a part, which can represent for him the added value of the output of the display of crime [20]. for the needs of the police, law enforcement and self-government, the added value of the output lines in the point representation of the crimes of the assessed area. the presentation of data in this form opens the space for the application of targeted and effective security measures, which can actively contribute to reducing the level of crime, which can ultimately positively affect the perception of crime by the population. acknowledgments this article was supported by the institutional grant project uniza interactive map of offenses of the selected site kor / 1041/2020 references [1] j. tomasek, introduction to criminology: how to study crime, bratislava: grada publishing, 2010. [2] r. kmet and z. dvorak, "information system for evaluating the level of crime in a selected region " in proceedings of the 2nd year of the scientific conference of doctoral students at the academy of the police force in bratislava, 2019. [3] l. hofreiter and a. byrtusova, safety indicators. 1st edition, zilina: edis, 2016. [4] c. d. daniyar, p. pihuave. et al, "the map of the victims. pertinence of the composed cognitive maps in the analysis of the criminal situation from a small territory perspective," politica criminal, vol. 15, no. 30, pp. 840-870, 2021. [5] j. c. t. arroyo, a. j. p. delima, m. y. orong, "indexed crime data visualization utilizing self-organizing map algorithm," international journal of emerging trends in engineering research, vol. 8, no. 9, pp. 5975-5978, 2020 [6] s. n. azmy, m. a. asmadi, m. z. a. rahman, s. amerudin, o. zainon, "burglary crime susceptibility assessment using bivariate statistics approach of information value model," iop conference series: earth and environmental science, vol. 540, no. 1, 012043, 2020 [7] m. szyszka, p. polko, "interactive maps of social problems and security threats illustrated with an example of solutions currently used in upper silesia," sustainability, vol. 12, no. 3,1229, 2020 [8] j. phiri, c. s. lubobya, "crime mapping model based on cloud and spatial data: a case study of zambia police service," international journal of advanced computer science and applications, vol. 11, no. 1, pp. 251-265, 2020 [9] s. matyas, "criminal geography as a new subject in the hungarian higher education" criminal geographical journal. vol. 1, no. 1, s. 45 – 52, 2019. [10] ministry of the interior of the slovak republic "map of crimes in the slovak republic (mapa trestných činov v slovenskej republike)" electronic portal of the ministry of the interior of the slovak republic. bratislava, 2021. [11] r. kmet, "crime map in the city of prievidza" diploma thesis. zilina: edis, 2018. [12] m. hornak, "crime map in slovakia" denník n, bratislava, 2015. [13] m. barborik, "crime map" project: maps of the future ii use of spatial data for the creation and pilot verification of tools and procedures for the analysis and prediction of crime to prevent and combat it, prague, 2020. [14] metropolitan police, "crime map for community policing" electronic portal of the police uk. london, 2021. [15] bundeskriminalamt, "interactive maps" federal criminal police office. wiesbaden, 2021. [16] tritech software systems, "crime mapping" san diego, california, 2021. [17] l. salvioli et al., "crime rate" sole 24 ore processing of data from the public security department – ministry of interior. rome, 2021. [18] l. gaspierik, prevention of crime and other anti social activities, kosice: multiprint, 2010. [19] t. van der heijden and e. t. kolthoff, "crime analysis as a tool for crime control" proceedings of the first international crime analysis conference. haag: cip-gegevens koninklijke bibliotheek. 2010 [20] r. kmet and z. dvorak, "crime index as one of the main indicators of safety" mest journal. vol. 8, no. 1, s. 57-64, 2020. [21] k. holcr at al., criminology. 1st edition, bratislava: iura ed, 2008. microsoft word 1-15_63.docx defense and security studies issn 2744-1741 vol. 1, no. 1, december 2020, pp.1-15 original research https://doi.org/10.37868/dss.v1i1.63 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/ ) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 1 axial force coefficient of apfsds projectile ammar trakić1 1 defense technologies department, mechanical engineering faculty, university of sarajevo; bosnia and herzegovina *ammar.trakic@hotmail.com © the author 2020. published by arda. abstract armor-piercing ammunition is primarily used to combat against heavy armored targets (tanks), but targets can be light armored vehicles, aircraft, warehouse, structures, etc. it has been shown that the most effective type of anti-tank ammunition in the world is the apfsds ammunition (armor piercing fin stabilized discarding sabot). the apfsds projectile flies to the target and with his kinetic energy acts on the target, that is, penetrates through armor and disables the tank and his crew. since the projectile destroys target with his kinetic energy, then it is necessary for the projectile to have the high impact velocity. the decrease in the velocity of a projectile, during flight, is mainly influenced by aerodynamic forces. the most dominant is the axial force due to the laid trajectory of the projectile. by knowing the axial force (axial force coefficient), it is possible to predict the impact velocity of the projectile, by external ballistic calculation, in function of the distance of the target, and to define the maximum effective range from the aspect of terminal ballistics. in this paper two models will be presented for predicting axial force (the axial force coefficient) of an apfsds projectile after discarding sabot. the first model is defined in stanag 4655 ed.1. this model is used to predict the axial force coefficient for all types of conventional projectiles. the second model for predicting the axial force coefficient of an apfsds projectile, which is presented in the paper, is the cfd model (eng. computed fluid dynamics). keywords: apfsds, axial force coefficient, stanag 4655 ed.1, cfd, prodas 1. introduction ammunition based on the use of kinetic energy (ke) penetrates through targets primarily with the energy of a projectile body or sub-projectile (penetrator), which is made of high-density metal. the efficiency of this ammunition depends on the impact velocity of the projectile at the target, the length, diameter and density of the penetrator. a representative of modern kinetic energy ammunition, which is mostly used today in armies around the world, is apfsds ammunition (armor piercing fin stabilized discarding sabot), which is made of an alloy of tungsten or depleted uranium [1]. the components of modern armor piercing fin stabilized discarding sabot ammunition are shown schematicallyy in figure 1: 1. penetration with fin stabilizer, 2. sabot, 3. combustible case, 4. propellant, 5. primer assembly, and 6. case base. dss vol. 1, no. 1, december 2020, pp.1-15 2 figure 1. main components of apfsds ammunition [2] during the movement of the apfsds projectile through the barrel of the weapon, the energy of the propellant charge acts on the bottom of the projectile (the penetrator is still connected to the sabot) and drives it. after the projectile comes out of the barrel, due to the difference in resistance and mass of the sabot and penetrator, the sabot separates and the penetrator continues to fly towards the target (figure 2). when moving through the barrel of the cannon, the projectile with the sabot reaches supersonic velocities (up to 5 mach). apfsds projectiles are statically stabilized projectiles. stabilization is provided using aerodynamic surfaceswings. when determining the axial force (axial force coefficient), the projectile body and the wings are observed separately. the sum of these two components of the axial forces on the apfsds projectile gives the total axial force (axial force coefficient) [4]. figure 2. process of discarding sabot from apfsds projectile [3] 2. models for prediction of coefficient of axial force there are many methods for predicting the axial force coefficient of apfsds projectiles, but all of them are based on the application of three general methods: 1. experimental (wind tunnel or polygon), 2. theoretical, and 3. numerical (cfd computational fluid dynamics). dss vol. 1, no. 1, december 2020, pp.1-15 3 experimental methods determine aerodynamic coefficients in an air (aero) tunnel or on the basis of measuring the movement of a projectile in flight (as a material point or a rigid body). this method gives the most realistic values for the axial force coefficient; however, the disadvantages of the tunnel experiment are [5]:  high price,  scaling problems if the model is not life-size,  interference from tunnel walls,  measurement difficulties. assumptions and simplifications are necessary in theoretical methods for the solving problems. this includes simplifying geometry and simplifying equations. equations known as navier-stokes equations, along with the energy equation and the continuity equation, describe the flow of fluid around a body. they are analytically unsolvable in closed form, but can be simplified for specific geometry or flight conditions [5]. numerical methods are new; they have been used since the advent of computers during world war ii. advanced cfd codes numerically solve navier-stokes equations and can show the complete flow field around an object for specific flight conditions. with these methods, problems arise in determining the boundary conditions, because the initial conditions must be defined with great accuracy [5]. in the continuation of this chapter, two models for predicting the axial force coefficient apfsds projectiles will be presented. the first model is presented in the stanag 4655 ed.1 standard. the second model for predicting the axial force coefficient of an apfsds projectile is the numerical model (cfd). the program to be used for the numerical simulation of projectile flow is ansys fluent. the presentation of the models as well as the results of the calculations will be shown below. 2.1. model defined in standard stanag 4655 (ed.1) the standard, stanag 4655, shows an engineering model for prediction of the aerodynamic coefficients of conventional projectiles. the details of the standard are given and are divided into three parts [6]: 1. body aerodynamics 2. fin aerodynamics 3. generalized yaw aerodynamics the axial force of a projectile can be divided into two parts: pressure axial force and viscous (friction) axial force. the complete axial force coefficient cx is finally obtained by summing up the relevant, separately calculated pressure axial force components and the viscous axial force obtained for entire wetted area. the total axial force coefficient of apfsds projectile (without sabot) is [6]: 𝐶 = 𝐶 + 𝐶 (1) where 𝐶 is axial force coefficient of projectile body and 𝐶 is axial force coefficient of fins. 2.1.1. axial force computation methods for projectile body the axial force of a projectile consists of the pressure axial force of the nose, base (including possible tail boom), protruding (driving band, grooves and steps), and of the viscous axial force as a sum of the following form [6]: 𝐶 = 𝐶 + 𝐶 + 𝐶 + 𝐶 (2) where 𝐶 is axial force coefficient of the nose, 𝐶 is axial force coefficient of the base, 𝐶 is axial force coefficient of the protruding and 𝐶 is viscous axial force coefficient. the axial force coefficient of the nose at supersonic region for a cone is calculated according to the formula (3) giving the pressure coefficient on the nose surface [6]. the second term takes into account the nose shape on drag force (see fig. 3). 𝐶 = 𝐶 = 𝑘 sin 𝜀 + 𝑘 sin 𝜀 (cos 𝜀) ( , , ) 𝑀 + [𝑅𝑅(1 − 𝑅𝑅)] , cos 𝜀 (𝑀 ≥ 1) (3) the coefficient k1 is an average pressure coefficient on a blunt projectile face behind a normal shock wave and the coefficient k2 takes into account the shape of the nose as a function of radius ratio parameter rr [6]. dss vol. 1, no. 1, december 2020, pp.1-15 4 figure 3. variable rr (radius ratio) [6] the coefficient k1 is computed from (4), and the coefficient k2 is computed according to (5). the radius ratio rr in the formulae is an inverse of the ratio of the true radius of curvature and the tangent-ogive radius r’ (formula 6). the nose contour line is to be extended to the projectile center line in case of blunted nose (see figure 3). the extended nose length is used in formula (6). the ratio rr is zero for cones [6]. 𝑘 = 5 3 − 2 3 𝑀√ (𝑀 ≥ 1) (4) 𝑘 = 0,9 − 0,9𝑅𝑅 + 𝑅𝑅 (5) 𝑟 , = 𝑙, 𝑑 + 𝑑 4 (6) the axial force coefficient of the base 𝑪𝒙𝒃 is computed from formula (7) [6]: 𝐶 = −𝐶 𝑑 𝑑 (7) the pressure coefficient 𝐶 is computed as [6]: 𝐶 = 𝐶 𝑑 𝑑 𝑥 = 2 when 𝑀𝑎 < 0.9, otherwise 1 (8) the pressure coefficient on the base of a long cylinder 𝐶 is computed at supersonic speeds (1.1 < ma) [6]: 𝐶 = −0,31𝑒 , (9) viscous axial force coefficient 𝑪𝒙𝒇 is calculated by formula [6]: 𝐶 = 𝐶 𝑆 𝑆 (10) where 𝐶 is average friction coefficient (11 or 12) for a smooth flat, 𝑆 is computed wetted surface area and s is reference area . the turbulent boundary-layer friction coefficient 𝐶 is computed by equation [6]: 𝐶 = 0,455 (log 𝑅𝑒) , (1 + 0,21𝑀 ) , (11) where 𝑅𝑒 is reynolds number , 𝑙 is projectile/nose length and 𝑣 is kinematic viscosity. the laminar boundary-layer friction coefficient 𝐶 is computed by equation [6]: 𝐶 = 1,328 √𝑅𝑒 (1 + 0,21𝑀 ) , (12) dss vol. 1, no. 1, december 2020, pp.1-15 5 the kinematic viscosity 𝑣 is computed from [6]: 𝑣 = 𝜇 𝜌 (13) the air density ρ is computed according to icao standard atmosphere. the dynamic viscosity μ is obtained from the sutherland formula [6]: 𝜇 = 𝐶 𝑇 , 𝑇 + 𝐶 (14) where 𝐶 = 1,458𝑒 / , 𝐶 = 110,4 [𝐾] and t is air temperature, obtained from icao atmosphere model. the axial force coefficient of protruding 𝑪𝒙𝒑𝒓 is computed by estimating the forward and backward facing surface pressure drag separately [6]: 𝐶 = 𝐶 + ∆𝐶 (15) the pressure coefficient sum (of the backward and forward facing parts) 𝐶 will change linearly between the sum and 0 when the ratio e/h (width/depth of groove) goes from 7 to 0 [6]. 𝐶 = 𝑒 7ℎ 𝐶 𝑒 ℎ < 7 (16) the formulae for the pressure coefficients at velocities above speed of sound are [6]: 𝐶 = (−0,067(𝑀 − 1) + 0,4) sin 𝜗 (17) 𝐶 = −0,65𝑀 , (18) where 𝜗 is angle of grove profile. certain types of finned projectiles have a relatively large groove pattern on the surface of the cylindrical part of body. these grooves are needed at the internal ballistic phase and after launch, the grooves cause an unfavorable flow retarding effect. the axial force coefficient of excessive amount of grooves (see figure 4) is computed in from formula [6]: ∆𝐶 = 1,6 𝑙 𝑙 𝐶 (𝐶 − 1) (19) the coefficient 𝐶 is the viscous drag coefficient (equation 10) of body cylinder part and the coefficient 𝐶 is used to take into account the groove depth on drag. the coefficient is the surface area ratio of grooved cylinder length to that of same length cylinder without grooves; the incremental drag will be zero in case the surface coefficient 𝐶 is 1 [6]. figure 4. groove pattern area on the surface of the cylindrical part of body [6] dss vol. 1, no. 1, december 2020, pp.1-15 6 2.1.2. axial force computation methods for projectile fins the axial force coefficient of fins (𝐶 ) is computed in the function of mach number, but also some effect of reynolds number is introduced via skin friction. the reference area is a circle area based on the diameter of the projectile cylindrical part. the axial force coefficient of fins consists of the wave drag (𝐶 ), axial force coefficient of leading edge (𝐶 ), axial force coefficient of trailing edge (𝐶 ) and viscous force coefficient of fins (𝐶 ) as a sum of the following form [6]: 𝐶 = 𝐶 + 𝐶 + 𝐶 + 𝐶 (20) the wave drag at supersonic speeds for fins with sharp leading/tailing edges (see fig. 5) is calculated according to the formula (21) [6]: 𝐶 = 𝑛 𝐾 𝑀 𝑡 𝑐 𝑆 𝑆 (21) where: k is shape correction factor (see fig. 5), is average fin thickness ratio, s is reference area, 𝑆 is fin area (see fig. 6), 𝑛 is number of fins. figure 5. airfoil shape correction factor k [6] figure 6. projected area of fins [6] the formula (21) is applied when mle ≥ 1 (mach number normal to leading edge). mle is supersonic if μ ˃ ˄lefin , where ˄lefi is sweep angle of fin leading edge (see fig. 7). the mach angle μ is then computed from expression [6]: 𝜇 = 𝑎𝑟𝑐𝑠𝑖𝑛 1 𝑀 (22) the drag coefficient value is taken to be constant down to free-stream mach number 1 if μ  ˄lefin [6]. figure 7. exposed wing geometry without body [6] fig. 8. schematic of fin blunt leading edge geom. [6] axial force coefficient of leading edge is obtained by multiplying 𝐶 by the number of fins (𝑛 ), taking the reference area (s) and fin dimensions (fig. 8) into account [6]: 𝐶 = 𝐶 𝑡 𝑏 𝑆 𝑛 (23) dss vol. 1, no. 1, december 2020, pp.1-15 7 the blunt leading edge average pressure coefficient 𝐶 is estimated by utilizing formula (24) [6]: 𝐶 = cos ˄ 𝐶 (24) parameter 𝐶 is estimated by utilizing formula [6]: 𝐶 = 𝑘1 (25) axial force coefficient of trailing edge is obtained by multiplying it by the number of fins (𝑛 ), taking the reference area (s) and fin dimensions (fig. 9) into account [6]: 𝐶 = 𝐶 𝑡 𝑏 𝑆 𝑛 (26) figure 9. schematic of fin blunt trailing edge geometry [6] the average pressure coefficient on a fin blunt trailing edge is computed at supersonic regions according to formula [6]: 𝐶 = −0,65 𝑀 , (27) viscous force coefficient of fins is calculated by same formulae (10) as in projectile skin friction drag. in fin case 𝑆 is the wetted surface area of fins, instead of the wetted surface area of projectile body and flow is consider to be turbulent [6]. 𝐶 = 𝐶 𝑆 𝑆 (28) the turbulent skin friction coefficient 𝐶 is computed by formula [6]: 𝐶 = 0,455 (log 𝑅𝑒 ̅) , (1 + 0,21𝑀 ) , (29) where: 𝑅𝑒 ̅ is reynolds number ̅ , 𝑐 ̅is mean aerodynamic chord (see fig. 7), 𝜈 is kinematic viscosity. 2.2. cfd-model (computed fluid dynamics) numerical simulation methods, using computed fluid dynamics, are an important aspect of modern research because they complement experimental and analytical models, reducing total time and labor costs. in the experimental approach, most of the time is spent designing the experiment and making the model. in the computational approach, most of the time is spent on generating a geometric mesh (if the flow area is geometrically complex) and later analyzing the results. the main disadvantage of the computer approach is limitation to problems for which there is a reliable physical / mathematical model [7]. in the general case, a numerical computational simulation consists of several main steps (fig. 10):  problem identification involves defining the objectives of numerical simulation, what are the modeling options, which physical models will be included in the analysis (viscosity, turbulence, compressibility), what simplifications can be used, whether user-defined functions should be used, what accuracy is required and how long it takes to get results [8]. dss vol. 1, no. 1, december 2020, pp.1-15 8  preprocessing involves defining the geometry, mesh (space discretization), physical model, and solver used [8].  solver settings include solver type selection, discretization scheme, solution initialization, convergence monitoring (stability analysis), and accuracy check (mesh independence check and mesh adjustment on a specific part of the domain) [8].  in the post-processing process, the results are examined and analyzed to understand the solution and extract useful data. visualization tools in numerical programs make it possible to gain insight into the field of pressures or velocities, to visualize flow vectors, to predict the position of shock waves. [8]. figure 20. process of numerical simulation [8] 2.2.1. mathematical model each simulation is based on a mathematical model, which denotes the mathematical notation of a physical model. the mathematical model includes the following assumptions [7]:  air is a continuum.  air is considered a homogeneous mixture of gases.  the physical properties of air are the same in all directions the air is isotropic.  air is a single-phase fluid.  mass forces are neglected. continuity behavior can be described by transport equations based on the basic laws of mass conservation, momentum, and energy. the equations derived from the given laws are presented in integral form for an arbitrarily selected part of the continuum, the volume ω bounded by a closed area the limit of the control volume dω (figure 11). the surface element ds is defined by the unit vector of the normal 𝑛 [7]. figure 11. control volume [7] dss vol. 1, no. 1, december 2020, pp.1-15 9 the characteristics of the air flow (pressure, tangential stress, velocity, temperature, etc.) are determined, at each point in space and at any time, by a system of differential equations [9]:  law of mass conservation: 𝜕 𝜕𝑡 𝜌 𝑑ω + 𝜌(�⃗� ∙ 𝑛)𝑑𝑆 = 0 (30)  law of momentum conservation: 𝜕 𝜕𝑡 𝜌 �⃗�𝑑ω + 𝜌�⃗�(�⃗� ∙ 𝑛)𝑑𝑆 = − 𝑝𝑛𝑑𝑆 + (�̿� ∙ 𝑛)𝑑𝑆 (31)  law of energy conservation: 𝜕 𝜕𝑡 𝜌𝐸𝑑ω + 𝜌𝐸(�⃗� ∙ 𝑛)𝑑𝑆 = 𝑘(∇𝑇 ∙ 𝑛)𝑑ω − 𝑝(�⃗� ∙ 𝑛)𝑑𝑆 + (�̿� ∙ �⃗�)𝑛𝑑𝑆 (32) where �⃗� is velocity of airflow, p is pressure, ρ is density, t is temperature, e is total energy, 𝜏̿ is stress tensor. 2.2.2. simulation of air flow around projectile the following will be adopted for all simulations [9]:  the problem will be observed as 3d geometry problem (because of fins).  the working fluid is air, an ideal gas, which is modified in accordance with compressibility and changes in thermo-physical characteristics with the temperature. density and viscosity depends on temperature, where cp and thermal conductivity are considered constant.  the flow around the projectile is compressible and turbulent (k-ε model of turbulence was used).  spatial domain discretization will be with a hybrid mesh.  the numerical density-based solver will be used, which simultaneously solves the equations of continuity, amount of momentum and energy. this method was developed for compressible highspeed flows.  the equations will be linearized in implicit form, i.e. for given variables; unknown values in each cell will be computed using relations that include both existing and unknown values from adjacent cells.  a uniform air flow encounters a projectile at a zero yaw angle. in order to reduce the number of finite elements, only the projectile segment was taken at an angle of 600 (figure 12). the calculation domain is limited by the external boundary of the projectile, symmetry planes and the outer boundary set at distances of 3 projectile lengths from the shell, 7 projectile lengths from the bottom and 6 lengths from the top (cylinder-shaped mesh) to avoid disturbances in free stream [9]. figure 12. 3d model of apfsds projectile 120 mm m829a2 [9] dss vol. 1, no. 1, december 2020, pp.1-15 10 the following types of boundary conditions were selected (figure13) [9]:  the "wall" boundary condition, which is used to separate the regions of fluid and solid matter, is placed on the outer boundary of the projectile. at the "wall" boundary condition, the "stationary wall" and "no-slip" options were chosen, because in the case under consideration, viscous effects cannot be ignored. the mass flux through the "wall" boundary is zero, and the pressure values at this boundary are obtained by extrapolation from inside the solution domain.  the "symmetry" boundary condition was used as a plane of axisymmetric geometry.  the "pressure far field" boundary condition, which is used to model the parameters of the compressible free stream at infinity, is set at the outer boundary of the calculation domain for given problem. figure 13. generated mesh around projectile 120 mm, m829a2, and boundary conditions applied [9] dss vol. 1, no. 1, december 2020, pp.1-15 11 3. results and discussion for prediction of the accuracy of the engineering model (from the nato related stanag 4655 standard) and cfd numerical model, a comparison was made in the research with the prodas model. for calculation of axial force coefficients, apfsds projectile, 120 mm, m829a2, was chosen. the reason for choosing this projectile model is because the aerodynamic coefficients are available from prodas program for this projectile model. the prodas software was developed to satisfy a need for rapid performance evaluation of ammunition characteristics. the development of an effective design/analysis tool for use by the design engineer in the development and evaluation of projectiles has been a multi-year project which began at general electric in 1972 and has continued at arrow tech associates, inc. since 1991. the developed tool is now called prodas which is an acronym for the projectile design/analysis system error! reference source not found.. from the smallest match bullets, to gps guided artillery shells, prodas brings together:  modeling building a model from a drawing or even a picture.  aerodynamics comparing aerodynamic coefficients from multiple aero estimators.  launch dynamics interior ballistics, balloting and jump.  trajectories fly 4dof, 6dof and body fixed and guided trajectories.  terminal effects estimate penetration of ke projectiles and lethality of fragmenting or shaped charge warheads.  system effectiveness using focused analysis or general purpose macros, compare projectiles or even gn&c algorithms error! reference source not found.. 3.1. stanag 4655 vs. prodas the axial force coefficients of the projectile body, predicted using the model from stanag 4655 and prodas models are shown in figure 14. the axial force coefficients of the projectile body predicted by the model from stanag (figure 14) shows a significant difference in the range of mach 3 to 5. it can be seen that this difference decreases with increasing mach number [9]. the axial force coefficients of the projectile fins, predicted using the model from stanag 4655 and prodas models are shown in figure 15. the downward trend in the value of the axial force coefficient of the fins in the stanag model is higher than in the prodas model. the differences between the values decrease slightly with increasing mach number (figure 15) [9]. figure 14. coefficients of axial force of the projectile body (120 mm, m829a2) [9] figure 15. coefficients of axial force of the projectile fins (120 mm, m829a2) the axial force coefficients of the projectile obtained by the model from the stanag 4655 standard, are smaller than the coefficients obtained by the prodas model (for projectile 120 mm, m829a2). the difference between the values of the coefficients obtained with model from stanag and prodas, decreases with increasing mach number (figure 16). the percentage difference of the coefficients obtained by the model from the stanag in relation to the coefficients obtained by applying the prodas model is given in figure 17. from figure 17 it can be noticed that the largest percentage difference between the predicted values of the model from the stanag and prodas is 16.3 % in the range of 3 to 5 mach [9]. 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 3 3.5 4 4.5 5 c x _b od y mach prodas stanag 4655 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 3 3.5 4 4.5 5 cx _f in mach prodas stanag 4655 dss vol. 1, no. 1, december 2020, pp.1-15 12 figure 16. coefficients of axial force of the projectile (projectile 120 mm, m829a2) [9] 3.2. cfd vs. prodas the results of the numerical simulation of air flow around projectile (120 mm, m829a2), in parallel with the results of prodas (function cx = f (m)) are shown in figure 18. the largest deviations are recorded for m = 3, where the difference is about 8.4 %. as the mach number increases, the difference decreases by almost 1 %. the percentage difference of the coefficients obtained by the numerical simulation in relation to the coefficients obtained by applying the prodas model is given in figure 19 [9]. based on the obtained results of numerical simulations, the analysis of the pressure and velocity field around the projectile 120 mm, m829a2 was done. the resistance force of a fluid that opposes the motion of a body in it arises as a result of the action of a normal force and a tangential force on the surface of a body moving through the atmosphere. the source of fluid resistance to body motion are practically three natural phenomena: fluid viscosity, shock waves (at velocities m ≥ 1), and turbulence flow behind the body [9]. figure 18. coefficients of axial force of the projectile (projectile 120 mm, m829a2) [9] figure 19. relative differences (cfd vs prodas) projectile 120 mm, m829a2 [9] the pressure and velocity fields, shown in figures 20 and 21, are complex. from figure 20, it can be seen that the free stream pressure is not the same for different mach numbers. as expected for the supersonic flow, oblique shock waves appear at the top of the projectile, while a characteristic underpressure zone appears behind the projectile. during supersonic flow, underpressure is created behind the rear part of the projectile. this underpressure causes the streams to bend towards the projectile axis. near the axis, the streams must bend again. in supersonic flow, the bent extension of the boundary layer draws air from the rear of the projectile so that a circular movement of air is created. generally speaking, the supersonic flow regime of any body is characterized by pronounced shock waves, extremely narrow areas of fluid in which the flow properties change discontinuously (extremely) in a very short time interval, with pressure gradients being extremely large. in front of the shock wave, there is a zone of undisturbed flow, while behind it there is a zone in which 0 0.2 0.4 0.6 0.8 1 1.2 3 3.5 4 4.5 5 c x mach prodas stanag 4655 0 0.2 0.4 0.6 0.8 1 1.2 1.4 3 3.5 4 4.5 5 c x mach prodas cfd figure 17. relative differences (stanag vs prodas) projectile 120 mm, m829a2 [9] dss vol. 1, no. 1, december 2020, pp.1-15 13 there are differences in the values of pressure, speed, temperature and density. figure 21 shows the boundary layer that forms around the projectile in flight. it can also be seen that the angle of the oblique shock wave decreases with increasing velocity at which the flow is simulated [9]. figure 30. pressure field around the projectile for different mach numbers [9] dss vol. 1, no. 1, december 2020, pp.1-15 14 figure 21. field of velocities around the projectile 120 mm, m829a2 for different mach numbers [9] dss vol. 1, no. 1, december 2020, pp.1-15 15 4. conclusion based on theoretical considerations and analysis of available models (stanag 4655 and cfd) for predicting the aerodynamic coefficient of axial force for wing-stabilized projectiles, the prediction of the axial force coefficient for apfsds projectile 120 mm, m829a2 was performed. the data obtained using the engineering model (from the stanag 4655 standard), and the data obtained by numerical simulation of projectile flow with the available data from the prodas database were compared. the following was stated:  the total axial force coefficients of the apfsds projectile (provided with the model from the stanag 4655 standard) have a satisfactory agreement with the total coefficient from the prodas model. the largest difference between the values is about 16.3 %. as the mach number increases, the difference decreases.  the advantage of the stanag 4655 model is that it allows the calculation of coefficients based on the geometric characteristics of the projectile without the use of computers.  the cfd model gives very good results, the values of the axial force or the axial force coefficient. good agreement between the results of the cfd model and prodas indicates that the initial and boundary conditions are well set.  the accuracy of the cfd model depends on the mesh, initial and boundary conditions. the accuracy of the cfd model can be increased by modifying the mesh (i.e. by increasing the number of finite elements). declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] a. ćatović: anti-tank projectiles, manual for students, university of sarajevo, mechanical engineering faculty, defense technologies department, sarajevo, 2019. 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[10] a. trakić: axial force coefficients of apfsds projectiles, master thesis, university of sarajevo, mechanical engineering faculty, defense technologies department, july 2020. microsoft word 34-43_148.docx issn 2744-1741 defense and security studies review article vol. 1, december 2020, pp.34-43 https://doi.org/10.37868/dss.v1.id148 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 34 industry 4.0 and smart cities: state of the art amel becic1 1 international university of sarajevo, bosnia and herzegovina *corresponding author: becic.amel98@gmail.com © the author(s) 2020. published by arda. abstract smart city is one of the most exiting industries of 21st century. the aim of this paper is to investigate the state of development of smart cities and its application. as a research method, the state-of-the-art research papers were analyzed. the key results presented in this paper show the impact of industry 4.0 on smart cities with technological advancements and its future developments. it was found that application of artificial intelligence within smart city industry will continue to grow in future as one of the main industry fields. the main objective in the future will be solving social challenges, enhance citizen wellbeing and specific endogenous problems. therefore, the focus will be more on people, governance and policy rather than technology and economy. keywords: smart city; industry 4.0; innovation 1. introduction in this research application of industry 4.0 technologies in smart cities is explored. a comprehensive state of the art literature is analyzed. after going through those materials, this paper presents the implementation of industry 4.0 with smart cities, various ways of implementation as well as advantages and disadvantages. difference between this paper and others found online is focus on connection of industry 4.0 and smart cities rather than exploring both topics separately. smart city researchers and arrangement creators frequently allude to the brilliant city along these lines inferring a homogenous methodology [1]. this underplays the significance of neighborhood conditions in molding one of a kind smart city imaginaries and on-the-ground ventures. as of not long ago, a smart city alluded to a glorified, mechanically determined, to a great extent mechanized city that was created starting from the top related to enormous information and innovation organizations. as the brilliant urban communities advertise has kept on advancing, urban areas are supporting what we call smart cities 2.0 techniques that put individuals first and stresses innovation as an instrument to utilize dominatingly in administration of residents [2]. this paper will also review the importance of industry 4.0 in smart city development. the technological advancement is moving quickly, empowering fabricating organizations with new opportunities for advanced changes to offer items and administrations to present and new markets at serious expenses. such present-day advancements are called industry 4.0 [3]. the term industry 4.0 starts from the german "industrie 4.0", created in 2011 in germany as a german federal government activity to fortify the intensity of the german assembling industry [4]. other chapters will include the integration of industry 4.0 into smart cities which will talk about how industry 4.0 helped to expand smart cities and rapidly increase development curve of the smart city [5]. future of smart cities will also have its own chapter and few perspectives based on different papers reviewed will be covered. it will try to answer the question what will happen in future, will industry 4.0 continue to be integral part of smart cities, will development of smart cities continue to rise in such a rapid rate etc. all those questions will be answered based on review of latest research papers written on this topic [6]. table 1 presents some of the references covering this topic. dss vol. 1, december 2020, pp.34-43 35 table 1. references on smart city and industry 4.0 topics scope result year reference smart city development describes the smart city 2016 [1],[2],[4],[7],[8], [11],[12],[14] industry 4.0 industry 4.0 introduction 2016 [13],[15], [16],[18] smart city architecture describes smart city development 2017 [24], [25], [31], [32],[41] smart city 2.0 describes future of smart cities 2019 [40], [42], [43],[45],[50], [52] industry 4.0 in smart city describes integration of industry 4.0 in smart city 2018 [21],[24],[27],[28],[30],[26],[39] smart city development describes the smart city 2018 [3],[5],[9],[10], industry 4.0 industry 4.0 introduction 2018 [17],[19],[20],[23],[33],[35],[36], smart city 2.0 describes new features of smart city 2.0 2019 [53],[54],[55],[56],[59],[37] industry 4.0 features describes new features of industry 4.0 2019 [61], [62], [64] architecture of smart city 2.0 describes newest architecture of smart city 2.0 2020 [46], [47], [48], [49] 2. industry 4.0 and smart cities the standard purpose behind the ascent of the smart cities initiative is making an acceptable model for urban networks and shield individual fulfillment of their inhabitants. the subject of the smart cities is not considered uniquely to be a specialized control, however extraordinary monetary, helpful or lawful viewpoints must be included [11]. in the possibility of industry 4.0, the internet of things (iot) can be used for the improvement of assumed splendid things. sub-fragments of these things are outfitted with their own insight. included knowledge is used both during the amassing of a thing, up to diligent checking of the things lifecycle (keen systems) [12]. interconnection of these structures can be depended upon transport structures. associating information from process-based industry 4.0 with smart vehicle systems of the city could make useful improvement of society [13]. germany is first to introduce industry 4.0. after germany, the term was spreaded all around the world. the name industry 4.0 alludes to the forward mechanical insurgency, with the initial three coming to fruition through automation, power, and it [14]. the forward mechanical insurgency, and henceforth the 4.0, will come about by means of the web of things and the internet of administrations getting incorporated with the fabrication. be that as it may, all the advantages of past upsets in industry came to fruition sometime later, though with the forward insurgency we get an opportunity to proactively control the manner in which it changes our reality [15]. figure 1. percent of people in usa living in urban area [67] dss vol. 1, december 2020, pp.34-43 36 the vision of industry 4.0 is that later on, modern organizations will construct worldwide networks to associate their hardware, plants, and warehousing offices as digital physical frameworks, which will interface and control one another by sharing data that triggers activities [16]. these digital physical frameworks will cover the state of processing plants, savvy machines, brilliant offices, and flexible chains. this will achieve upgrades in the modern procedures inside assembling in general, through building, material utilization, flexible chains, and item lifecycle [17]. at the focal point of this vision will be the processing plant, which will adjust the way creation is performed [18]. it won't be simply digital physical systems such as keen hardware that will be smart; the items being gathered will likewise have insight of the goal that can be recognized all through the assembling procedure [19]. the vision held is that the installed frameworks are coordinated with the vertical business forms, (deals, coordination, and funds, among others) and related it frameworks. they will empower savvy manufacturing plants to control the start to finish the board of the whole assembling process from flexible affixes through to administrations and lifecycles. notwithstanding, in the industry 4.0 framework, these elements will go about as one. keen production lines don't relate just to tremendous organizations, undoubtedly, they are perfect for little and medium-sized endeavors as a result of the adaptability that they give [22]. for instance, authority over the level assembling process and brilliant items empowers better dynamic and dynamic procedure control, as in the ability and adaptability to take into account plan changes or to change creation to address a client's inclination in the items plan. moreover, this dynamic procedure control empowers little parcel sizes, which are still beneficial and oblige singular custom requests. these dynamic businesses and designing procedures empower better approaches for making inventive plans of action [23]. table 2. industry 4.0 technologies and e-learning capacities industry 4.0 technologies e-learning yes no production and scheduling software 41% 28% digital visualization 30% 8% production for safe human-machine interaction 12% 6% product exchange 25% 20% programming devices 12% 4% product managment system 14% 5% 3. integration of industry 4.0 in smart cities today the greater part of total population lives in urban territories (fig. 1). worldwide urbanization shows expanding advancement. in spite of the way that world's surface is involved by just 2% of urban territories, urban settlements amass over half of population and expend up to 75% of regular assets [24]. subsequently, the issue of "brilliant" urban turn of events, recovering arrangements of population development and relocation issues, environmental change, instruction and wellbeing, reasonable lodging and urban life change affected by data and correspondence advancements (icts, computerized advances) with regards to fourth mechanical upset have pulled in expanding consideration in the last decade and the issues of "smart" urban advancement are talked about in various configurations [25]. present day investigations of future (or "shrewd") urban areas have a few multidisciplinary contents. among them issues with respect to practical social, natural and financial improvement of urban areas and issues with respect to complex city biological systems the board in order to access fundamental assets like lodging, clean air, clean water for whole occupants. the maintainable cities index incorporates these parts of the "smart city" idea. for instance, the 5top of worldwide urban areas are zurich, singapore, stockholm, vienna and london [26]. moscow positions 57. in general. enthusiasm of the scientists concentrated on the "computerized city" during the 1990s, as the significance of "advanced" had been expanded when the eu government upheld the program "european digital city" in 19961999. during this period, enthusiasm of scientists, government officials and financial specialists was centered around advancement of various data administrations for residents giving collaboration of urban occupants furthermore, region by utilizing new innovations. motivation behind this program was to choose 15 urban areas and help them in figuring it out the potential being developed and advanced strategy execution which would change lives of occupants, organizations, laborers and business people. in 2008, ibm ceo samuel j. palmisano, noticed that "our planet is getting more astute" on the grounds that the world has been progressively outfitted with "computerized" instruments (sensors are being brought into all biological systems). the world is turning out to be increasingly interconnected and progressively smart (developing new dss vol. 1, december 2020, pp.34-43 37 processing forces, models and supercomputers) [27]. dynamic improvement of the "brilliant" culture started toward the finish of the principal decade of 2000's when "shrewd" prefix started showing up in varieties word articulations like "shrewd turn of events", "keen development", "brilliant guideline", "shrewd city", "keen plant", "smart home" [28]. 4. smart city development based on industry 4.0 in the idea of "smart city" adequate significance was recently given to giving residents open administrations. rising new ict age is causing all components of city and its foundation (economy, transport, instruction, clinical consideration, open request, and the board) to become "smarter" [8]. from one perspective, advancement of internet of things, coordinated frameworks and their worldwide systems administration (for instance, keen vehicle arrange that is utilized to manage blockage), of digital physical frameworks to make new open doors for building "keen city" and progress to "smart economy" in view of industry 4.0 [29]. improvement of industry 4.0 will take care of certain issues of assets and vitality proficiency, urban creation, segment changes in megacities. industry 4.0 makes creation innocuous to urban condition. creation gets scholarly, advanced and coordinated not just at the level of a straightforward processing plant. advanced innovations make conditions for level coordination which is going past the "keen industrial facility" and advance computerized chains of significant worth creation at nearby, provincial, national and worldwide levels [9]. then again, the advancement of "smart urban areas" as an objective of urban, modern, monetary, social, natural arrangement advances new industrialization and digitization of current economy. "shrewd urban communities" are making progressively alluring conditions for living, work, training, human capital, pulling in money related assets for business improvement [30]. the expression "smart urban communities" is applied not exclusively to urban communities; it deals with today more generally. "smart urban communities" can be viewed as agglomerations or "uber centers" of the present advanced economy [31]. it is fundamental to think about turn of events of industry 4.0 as formation of "savvy urban communities" and agglomerations just as different items like "brilliant processing plant", "keen home", "brilliant road", "shrewd grounds" and others which are mutually molding computerized economy at the degree of the city, locale, nation. new computerized innovations are not just changing straightforward creation into esteem chains dependent on the internet of things and digital physical frameworks and making new types of cooperation underway frameworks yet in addition making new connections between makers, providers and clients [33]. industry 4.0 is making mechanical and innovative reason for rising "shrewd urban communities" whose advancement and incorporation turns into an indispensable component of economy digitalization. a shrewd city additionally needs a huge measure of information stockpiling, which can be accomplished through state, an electrically tunable metasurface [34]. this innovation could influence a scope of fields, (for example, imaging, correspondence, encryption, and information storage). the reaction of guaranteed shrewd city to unsure information is noteworthy, prompting the topic of how to measure the heartiness of a shrewd city. an evaluation structure must mull over different attributes, including shrewd city methodology and the interests all things considered, (for example, evaluators, ict foundations, legitimate and administrative strategies, administrations, plans of action, and supportability). the goals of such a system are to look at the qualities of various keen urban areas to distinguish new difficulties, evaluate benefits, and assess execution. in shrewd urban communities, effective security support is a significant necessity of vanets. one thought is the manner by which to make sure about them by structuring arrangements that lessen the probability of system assaults or even how to lessen the impact a fruitful assault could have on them. a keen city needs lightweight, adaptable confirmation systems that secure drivers from interior and outside assailants. the ieee 1609.2 v2 standard determines a lot of security administrations (for example, testament expert) for supporting vehicular interchanges. open key infrastructure-based (pki-based) answers for check vehicle security probably won't lead to an adaptable arrangement. cross-affirmation ought to be characterized when nations or urban areas have numerous root declaration specialists. the power answerable for trouble making identification ought to be joined into the pki framework. structuring and sending keen urban areas needs specialists from different fields, counting financial aspects, humanism, building, ict, and arrangement and guideline [37]. different systems depicting the engineering of brilliant urban communities have been proposed by both industry and scholarly sources. one of the most generally adjusted and embraced models is the reference model proposed by the u.s. national institute of standards and technology. keen urban areas are perplexing frameworks, frequently called "frameworks of frameworks", including individuals, foundation, and procedure segments. generally shrewd urban community models comprise of six segments: government, economy, portability, conditions, living, and individuals [38]. different methodologies and techniques have dss vol. 1, december 2020, pp.34-43 38 been proposed to assess keen urban communities from numerous points of view, including a urban internet of things (iot) framework for brilliant urban areas, manageability, worldwide city execution, future urban situations, urban seriousness, and strength. figure 2. adoption of industry 4.0 by sector [68] 5. future of smart city advancement of "smart city" basics was joined by development this idea content [40]. prior, the smart city idea concentrated more on advancement of smart considered as a complex environment whose administration required arrangement of consistent access to essential assets without harm to nature [41]. in this manner, with the developing effect of new "advanced" innovations applied on the procedure of urbanization, specialists concentrated on "digitalization" and improvement of different data administrations [42]. at long last, advancement of industry 4.0 innovations (web of things, distributed computing, digital physical frameworks, large information and others) has made it conceivable to make entire urbanization process more brilliant: urban arranging and development ("keen home"), creation and business ("smart processing plant" and "keen economy"), the board ("brilliant guideline") what's more, to make conditions for improvement and aggregation of social and human capital ("shrewd population") [10]. in this way, industry 4.0 advances are creating today an in a general sense new foundation of the "smart city", making new open doors for settling specific issues with respect to assets and vitality effectiveness, urban creation association, segment changes in present day megacities. thus, "smart city" improvement turns into a type of new industrialization of the advanced economy [43]. the solid enthusiasm by metropolitan governments worldwide in smart city communities originates from their capacity to improve their residents' nature of life. here, we depicted a portion of the fundamental ideas of savvy urban communities, distinguishing difficulties and future research chances to empower enormous scope arrangement of savvy urban areas [44]. engineers, modelers, and originators ought to presently center around parts of iot the board, information to the executives, savvy city appraisal, vanet security, and inexhaustible innovations, (for example, sun-oriented power) [45]. we trust to see shrewd city engineers, planners, and creators give adaptable, financially savvy answers for address them later on [46]. figure 3. smart city infrastructure investment by industry (2014-2023) [69] dss vol. 1, december 2020, pp.34-43 39 6. research on the world of smart cities there is plenty of new research activities around the world. it begun with the ibm smarter planet initiative1, rapidly followed by the mit city science program. what's more, trinity's smart and sustainable cities initiative3 , all tending to fundamental parts of this dynamic field. in any case, the majority of these activities center around a shut arrangement of subjects, which prompts a somewhat restricted, nearness driven view on the space [47]. so as to empower a really comprehensive interdisciplinary and future evidence approach, it is imperative to address the space of brilliant urban areas on a more elevated level of reflection [48]. i.e. to empower the recently presented ideal smart city [49]. we have to make the logical underpinnings for future web of cities infrastructures (ioci). to guarantee this, a far-reaching set of systems, models, and instruments for plan, improvement, the executives, and advancement of next generation shrewd city applications is required. such work requirements is to follow a standards as a way to tackle the great difficulties of future shrewd urban areas through close reconciliation of analysts and partners from various spaces to make an open, comprehensive, and interdisciplinary research stage [50]. 6.1. metodology the subsequent significant focal point of the ioci will be on formulating an exhaustive procedure to help partners in structuring, creating, and advancing reusable and viable keen city applications. we will put together our exploration with respect to madcat [5], an iterative programming designing approach for cloud applications with an express spotlight on curiosity detectability, reuse, and improved partner correspondence. expanding on endeavors of intently coordinating partners from various areas into the way toward making shrewd city applications, we will make an all-encompassing approach for building shrewd city applications that unequivocally empowers the plan and improvement of reusable and freely viable application parts in close participation with master partners [51]. the philosophy will permit for a capacity arranged methodology for catching and bundling required usefulness in particular, reusable units that can be shared and coordinated in numerous applications [52]. such units characterize their normal condition by means of plainly determined interfaces, taking into account the consistent mix of demonstrating furthermore, recreation situations, just as genuine foundation, giving an unmistakable deliberation between the framework being worked on and its execution surroundings, for example, testing, organizing, and creation, each with varying degrees of reproduced condition resources [53]. to dependably work and oversee future brilliant city applications, the third mainstay of the ioci is a farreaching toolset that will permit administrators to consistently convey and execute complex applications in an autonomic, repeatable, and perceptible way. so as to do as such, we will separate these devices in three unique layers that expand upon one another. on the most minimal layer (framework layer), building the establishment, one needs to oversee and screen the accessible shrewd city foundation, comprising of independent servers, cloud situations, edge foundations [54]. in the framework layer we need an exhaustive toolset that permits administrators to uncover, oversee, and screen the basic framework in a uniform and extensible way. in light of the framework layer, one needs to give a runtime layer to shrewd city applications that permits and supports the accompanying key perspectives. to begin with, the runtime layer needs to help versatile application arrangement thinking about the focusing on framework, anticipated number of clients and required information volume. second, the runtime layer needs to give a runtime domain to executing savvy city applications that permits to consistently scale applications across different foundations [56]. third, to manage the extent of information positions, tremendous information volume the runtime layer needs to give productive and versatile information on the board, comprising of information intercession, change, handling and capacity. at last, since different keen city applications can be executed at the same time, the runtime layer needs to give both versatile information and application confinement levels, that permit various inhabitants to work at the same time without meddling each other. the last layer (mix layer of our toolset is then answerable for incorporating novel keen city application advancement techniques, models, and reproductions [57]. the reconciliation layer bolsters diverse application improvement and organization stages (i.e. reenactment, testing, creation, and rollout), which gives administrators and engineers diverse application runtime situations by getting to either mimicked or genuine frameworks. furthermore, the reconciliation layer opens interfaces to recover information that is gathered during the execution of uses also, the administration of the basic foundation, in request to i.e. feed recreations, extricate utilization designs, or create models [58]. 6.2. modeling modeling face difficulties because of an absence of accessible real-world framework to make and confirm applications in wording of usefulness, non-utilitarian properties, or administrative necessities [59]. current dss vol. 1, december 2020, pp.34-43 40 arrangements either depend for little scope testbeds or exclusive, hand crafted reenactments to copy true situations (e.g., anylogic5) [60]. be that as it may, such arrangements are a long way from perfect, as changes in realworld conditions should be physically repeated in lab testbeds or recreations, and the relocation of uses from test framework to certifiable arrangements must be painstakingly arranged and physically completed for each new application variant [61]. moreover, brilliant city applications being worked on in part depend on information that is now accessible in the physical condition, and subsequently would profit from utilizing certifiable information rather than recreations if conceivable. inside the ioci, this test will be tended to by grasping the requirement for displaying and reproducing portions of an application's condition, just as incorporating genuine world information from the physical condition at various stages during its lifecycle at the center of our examination endeavors [62]. 7. conclusions introduction of industry 4.0 brought a lot of possibilities for many industries to profit. the one of it that profited the most are smart cities. industry 4.0 integrated into smart cities and is helping them to become more efficient using technologies like cloud and iot. one of the most significant reactions for the past three mechanical insurgencies and their related approaches is the inability to understand the most problems that are begging to be addressed that keep on confronting present day social orders. these incorporate environmental change, ceaseless maladies, and imbalance. with the progress to industry 4.0, arrangement producers should think its worldwide effect on present and potential social issues through the social components of new advancements. society on the loose should profit by such modern change, since purchaser and maker are to a great extent associated also, both can take an interest in the creation and utilization process. smart cities will surely profit from integration of industry 4.0. industry 4.0 focuses on energy efficiency and reliability and it is absolutely essential in modern smart city. artificial intelligence from industry 4.0 will help in enhancing urban transportation, water management etc. but all in all, most important aspect which industry 4.0 adds into smart cities is sustainability [63]. ability of controlling all parts of the process will make it easier to conserve raw materials and energy. all in all, we can conclude that industry 4.0 will definitely radically improve smart cities development and implementation. one of the reasons why smart city industry is booming is because there is a big rise of people living in urban areas and they all present the possible residents (as shown in figure 1) [ 64]. as this paper discussed in chapter 4 the development of internet of things as well as all digital technologies made it easier and more flexible to develop new ways of improving smart cities through digitalization and most importantly artificial intelligence [42]. artificial intelligence development will continue to rise in future as one of the main industry fields, and with its rise smart city industry will also profit. the future of smart cities as discussed in chapter 5 is all about focusing on people, governance and policy rather than technology and economy. that is the policy of “smart city 2.0” [65]. the main objectives of “smart city 2.0” are to migrate and solve social challenges, enhance citizen wellbeing and enhance specific endogenous problems. the approach of new smart cities is decentralized rather than centralized [66]. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] g. trencher, “towards the smart city 2.0: empirical evidence of using smartness as a tool for tackling social challenges,” technol. forecast. soc. change, vol. 142, no. july, pp. 117–128, 2019. 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[67] reasearchgate.net [68] globalskillsumit.com [69] wikipedia.com microsoft word 79-85_172.docx issn 2744-1741 defense and security studies original research vol. 2, may 2021, pp.79-85 https://doi.org/10.37868/dss.v2.id172 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 79 analysis of the influence of 5.56 mm projectile shape on drag coefficient using cfd tarik šabanović1 1 mechanical engineering faculty, university of sarajevo, bosnia and herzegovina *corresponding author: : tariksabanovic2203@gmail.com © the author 2021. published by arda. abstract this paper describes the computer dynamics of fluids, which was used to determine the influence of certain geometrical characteristics of the projectile on the coefficient of drag force. the first section is an introduction and describes the projectile, the aerodynamic forces acting on the projectile with special reference to drag. the second section was reserved for a review of projectile parameters that affect drag, primarily the slenderness of the ogive and the frustum, and the shape of the ogive, and the angle of the frustum. this section also defines drag in more detail. the third section describes the mathematical model of fluid in supersonic flow and gives the equations for the mathematical model, used in simulations and software package ansys fluent. this section was also reserved for describing the emergence of a physical model and the verification of the numerical simulation model. the fourth section presents and describes the model of cfd analysis of 5.56 mm projectiles: ss109, m855, l110, and m856, and the comparison of projectiles by geometry. the fifth section comprises the analysis of the results. in the sixth section, a conclusion is given. keywords: cfd, small caliber ammunition, aerodynamics, drag force 1. introduction small caliber ammunition includes ammunition up to 12.7 mm caliber and is typical ammunition for weapons for personal protection. it is fired from direct fire weapons that have high initial velocity and flatter trajectory. ammunition, in the general case, consists of a projectile and a propulsion group. projectiles of small caliber ammunition generally do not contain explosive charges and fuse, and use only kinetic energy upon impact. due to the movement of the projectile through the air, the air environment is disturbed; the air is forced to move and the parameters of the state changes which requires a certain amount of kinetic energy. the force with which the air acts on the projectile, which is the resultant of all forces acting on the surface of the projectile (namely the force of pressure acting normally on surface and friction force acting tangentially to the surface), and has a velocity in the opposite direction, is called the drag. in aerodynamics, in order to avoid difficulties with dimensions, we work with dimensionless quantities [1]. three reference quantities are used by which other quantities can be used to make it dimensionless and these are: reference length, reference area and reference pressure (dynamic pressure in undisturbed air flow). the force of drag that divided with the product of the reference area and the reference pressure gives a dimensionless quantity called the aerodynamic drag coefficient. empirical formulas were obtained on the basis of theoretical calculations and experimental tests which can be used to predict the pressure distribution, i.e. for the aerodynamic coefficient estimation, on a specific part of the projectile for a defined range of flow velocities. based on these empirical expressions and the development of computer technology begins the era of computer programs for prediction of aerodynamic dss vol. 2, may 2021, pp.79-85 80 coefficients based on the geometric characteristics of the projectile. the rapid advancement of computer technology has introduced a new discipline called computational fluid dynamics (cfd computational fluid dynamics) which represents the third method in aerodynamics completing the previous two, pure theory and pure experiment. computer fluid dynamics is the art of approximating major partial differential equations which describe fluid flow by simple algebraic expressions [2]. the end result of the application the cfd on the projectile flow is a picture of the flow field around the projectile which allows for a detailed analysis of the influence of individual parameters on the pressure (velocity) distribution and thus on aerodynamic drag coefficient. 2. influence of projectile shape on drag force coefficient in addition to the flow velocity (represented through mach number), the aerodynamic drag coefficient in large extent depends on the geometric characteristics of the projectile. slenderness of the projectile implies the ratio of the length of the projectile to the reference diameter of the projectile. figure 1. shows the dependence of the drag coefficient on the mach number for the three shapes of projectiles. the upper curve represents the drag coefficient for a spherical projectile, the middle curve corresponds to the drag coefficient for the projectile without the rear cone and with front part made with small slenderness, and the lower curve is the drag coefficient of a modern projectile. in terms of projectile slenderness, the sphere has the lowest slenderness and the modern projectile has the greatest slenderness. figure 1. coefficient of drag as a function of mach number depending on the shape [3] all three curves shown in figure 1. have the same trend. in the subsonic area the drag coefficient is constant (middle and lower curve) or changes very little, in the transonic area rises sharply to its maximum value and begins to slowly decline. the trend of a slight decrease in the drag coefficient with an increase in the mach number continues in the supersonic range. it can also be noticed that projectiles with higher slenderness have smaller drag coefficient and that their maximum value of the drag coefficient occurs for the values mach's number closer to one. 3. mathematical model aerodynamics is a theoretical and experimental science, and represents a branch of fluid mechanics. theoretically approach is based on the analytical solution of mathematical models of air flow. an analytical solution gives a complete insight into the physics of a problem, and once determined the analytical solution is suitable for the analysis of the influence of individual parameters in the mathematical model. most airflow problems are described by nonlinear partial differential equations, which do not have a general analytical solution. this is especially true for turbulent flow, which due to the stochastic nature of that flow cannot be described analytically. with the development of computers, conditions were created for the numerical solution of mathematics model. each simulation is based on a mathematical model, which denotes a mathematical notation physical model. dss vol. 2, may 2021, pp.79-85 81 the mathematical model includes the following assumptions:  air is a continuum.  air is considered a homogeneous mixture of gases.  the physical properties of air are the same in all directions the air is isotropic.  air is a single-phase fluid.  mass forces are neglected. the continuum assumption implies that the density of the fluid is large enough that even the infinitesimally small element of the fluid contains a satisfactory number of particles so it is possible to specify average velocity and average kinetic energy. that way they can determine flow characteristics (velocity, pressure, temperature, etc.) at each fluid point [4]. continuity behavior can be described by transport equations based on the basic laws of mass conservation, momentum, and energy. the equations derived from the given laws are presented in integral form for an arbitrarily selected part of the continuum, the volume ω bounded by a closed area the limit of the control volume dω (figure 2). the surface element ds is defined by the unit vector of the normal 𝑛 [4]. figure 1. control volume [4] law of mass conversation states: 𝛿 𝛿𝑡 𝜌𝑑𝛺 + ρ(�⃗� ∗ 𝑛) 𝑑𝑆 = 0 (1) law of momentum conservation implies: 𝛿 𝛿𝑡 𝜌𝑣 𝑑𝛺 + ρ𝑣(𝑣 ∗ 𝑛) 𝑑𝑆 = 𝜌𝑓 𝑑𝛺 − ρ(𝑛) 𝑑𝑆 + (𝜏̿ ∗ 𝑛) 𝑑𝑆 (2) law of energy conservation states: ∫ 𝜌𝐸 𝑑𝛺 + ∮ ρe(�⃗� ∗ 𝑛) 𝑑𝑆= ∮ k(∇t ∗ 𝑛) 𝑑𝑆 + ∫ 𝜌𝑓 ∗ 𝑣 + 𝑞 ̇ 𝑑𝛺 − ∮ p(𝑣 ∗ 𝑛) 𝑑𝑆 + ∮ (𝜏̿ ∗ 𝑣) 𝑑𝑆 (3) here 𝑣 is velocity of airflow, p is pressure, ρ is density, t is temperature, e is total energy, and �̿� is stress tensor. the system of equations describing high-velocity flow cannot be solved analytically. to solve this system it is necessary to introduce a simplification or a problem or the equations. with the development of computers and computer fluid dynamics (cfd) numerical solution of equations describing the flow can be obtained. 4. solving equations using cfd numerical solution of a mathematical model that describes the flow in the considered problem consists of three steps. in the first step, the area is discretized. result of discretization of space is called a geometric grid. on the defined geometric grid it is necessary to discretize the partial differential equations of the mathematical model, respecting specific boundary conditions. the discretization of the equations is carried out by some of dss vol. 2, may 2021, pp.79-85 82 the known methods (finite volume method, finite element method, finite difference method etc.). result of discretization of partial differential equation on given geometric web is a system of algebraic equations. the nonlinear system of equations is solved iteratively by a procedure that involves solving a system of linear algebraic equations. a numerical solution is obtained, followed by its analysis, which includes a display of scalar, vector and tensor fields, integration of flow, force, moments, thermal flows, etc., and a diagram of the desired quantities. one of the main prerequisites for using a cfd model is validation model that takes place in several steps [4]:  checking the program code.  comparison of the obtained results with the available experimental data (predicting measurement errors).  sensitivity analysis and parametric study.  application of different models, geometry and initial/boundary conditions.  reports on findings, model limitations, and parameter settings. the aerodynamic drag coefficient of the sphere was used here to verify the flow model for which experimental data are available [3]. the physical model of this case, the sphere in air flow, is shown in figure 3. figure 2. sphere in air flow the diameter of the sphere in the simulations was 2.54 mm and the flow was simulated at different velocities (2; 2.5; 2.64 and 3 mach). pressure and temperature of free air flow in all simulations were: p∞ = 101325 pa and t∞ = 300 k. figure 3. drag coefficient as a function of mach number for spheres with different diameters figure 4 shows a comparison of experimental and numerical results obtained. for free air flow velocity of ma = 2.64 (point c) by numerical simulation the value of the coefficient of drag for the sphere, with diameter 2.54 mm, was cd =0.95, which is about 1% higher than the value obtained experimentally. deviation (relative difference) observed were as follows: for m = 2 the deviation was 3%, for m = 2.5 the deviation was 4%, for m = 2.64 the deviation was 5% and for m = 3 the deviation was 4%. comparing the values, very good agreement was observed between the experimental values and values determined using the ansys fluent software package. dss vol. 2, may 2021, pp.79-85 83 5. analysis of results the flow for four 5.56 mm projectiles with different (supersonic) velocities was considered in the research. the following assumptions were adopted for all simulations:  working fluid is air, an ideal gas, which is modified in accordance with compressibility and changes in thermo-physical characteristics with temperature.  density and viscosity depend on temperature, and cp and thermal conductivity are considered constant.  the parameters of free air flow were: p∞ = 101325 pa and t∞ = 300k.  the flow around the projectile is considered compressible and turbulent.  discretization of the spatial domain was performed by non-uniform unstructured mesh.  a "density-based solver" was used, developed for compressible high-speed flows.  the equations were linearized in implicit form, i.e. for given variable, unknown in each cell was calculated using relations that include existing and values from adjacent cells. the flow field around the projectile and the aerodynamic drag coefficient were determined by using fluent program for specified conditions. four small-caliber projectile were used for num. simulations; for these projectiles experimentally determined values of aerodynamic drag coefficient [5] were known. models used were:  5.56 mm ss109,  5.56 mm m855,  5.56 mm l110,  5.56 mm, m856. simulations with free flow for each of the projectiles was performed for velocities in the range of 1.2 up to 3 mach for the following values of mach numbers: 1.2; 1.5; 1.7; 2; 2.5; 2.64 and 3. although all observed projectiles consist of a front part, a cylindrical part and a rear part, on projectiles ss109 and m855 the rear part have the shape of a bevelled cone and on projectiles l110 and m856 the rear part have the edged shape. for this reason, two groups will be formed in the analysis of results. the first group consists of projectiles with a conical rear part, ss109 and m855, and the second group consists of projectiles with a edged rear end, l110 and m856. the results of the simulations, in the form of the drag coefficient values, for the first group of projectiles are shown in figure 5. in figure 5. are also presented the results of experimental tests for projectiles ss109 and m855. figure 4. drag coefficient vs mach number for projectiles 5.56 mm, models ss109 and m855 [5] 0.25 0.3 0.35 0.4 0.45 0.5 1 1.5 2 2.5 3 cd ma ss-109/m855 ss-109 m855 experimental data ss109 experimental data m855 dss vol. 2, may 2021, pp.79-85 84 from the figure 5. it can be seen that the agreement of experimental and numerical data in supersonics is very good and the maximum rel. error is 2%. agreement in transonics is somewhat lower, with rel. error of 10%. it can be noticed that the 5.56 mm ss109 projectile has a lower drag coefficient than the 5.56 mm projectile m855 in the supersonic range. observing the pressure distribution [5] around the projectiles 5.56 mm, ss109 and m855, shows that the ss109 projectile has a lower maximum pressure at the top of the front part in relation to the pressure at the top of the front part of the projectile 5.56 mm, m855; this also results in less drag on this part of the projectile. if we compare the pressure distribution at the rear for these two projectiles, it can be seen [5] that the m855 projectile has a lower bottom pressure than the ss109 projectile at the same velocity flow, which results in a higher coefficient of drag for this part and in accordance with the theoretical considerations 5.56 mm projectile ss109 has a slightly larger slenderness of the front part, significantly higher slenderness of the rear end and approximately the same overall slenderness in relation to the 5.56 mm m855 projectile; although it has larger angle of inclination of the rear cone, which is unfavorable, it can be stated that it is better aerodynamically shaped from a 5.56 mm projectile, m855, for flight at supersonic speeds. simulation results, drag coefficient vs ma number, for the second group of projectiles, projectiles 5.56mm, l110 and m856, are shown in figure 6. together with the experimental data. figure 5. drag coefficient vs. mach number for 5.56 mm projectiles, models l110 and m856 [5] on figure 6. it can be seen that the agreement of the experimental with the numerical results is very good and that many points actually match. observing the pressure distributions flowing around the front of the 5.56 mm projectile l110, and around the front part of the projectile 5.56 mm m856, it can be noticed that the pressure at the top of the front of the projectile m856 is less than the pressure at the top of the projectile l110, which also results in less drag on this part. the front of the l110 projectile is also slimmer from the front part of the m856 projectile, resulting in a lower drag coefficient of the front part of the projectile. considering the pressure distribution at the rear of the l110 projectile and at the rear projectile m856, a lower pressure is observed at the rear and at the bottom of projectile 5.56 mm l110. although the m856 projectile has a greater slenderness of the rear and smaller coefficient of drag at the bottom, it can be concluded that the greatest influence on the total coefficient of drag in the supersonic area have the shape and slenderness of the front part of the projectile. figure 6. shows that the 5.56 mm projectile l110 has a lower drag coefficient than projectile 5.56 mm m856 in the considered velocity range. in the range of velocities up to mach 1.5, the trend of the l110 projectile drag curve is the same as the trend of the coefficient curve for projectile m856. at the flow rate m = 1.7, the value of the drag coefficient projectile l110 approaches the value of the drag coefficient of the projectile m856, where the rel. difference is less than 5%. with a further increase in the flow rate, this difference decreases and for m = 3 it is less than 4%. more data from this research can be found in reference [5]. 0 0.1 0.2 0.3 0.4 0.5 1 1.5 2 2.5 3 cd ma l110/m856 l110 m856 experimental data m856 experimental data l110 dss vol. 2, may 2021, pp.79-85 85 6. conclusions in this paper, the influence of projectile shape for 5.56 mm ammo on aerodynamic drag coefficient is analyzed at supersonic velocities, using computational fluid dynamics. during these analyses, the following was found:  shorter, blunt projectiles have a higher drag coefficient than slender projectiles.  in the supersonic range, the length of the fornt part has a large influence on the drag coefficient and with increasing slenderness of the front of the projectile comes a significant reduction of the coefficient of drag.  at higher (supersonic) velocities, the front of the projectile shaped like a secant has the lowest drag, less so than the conical and tangential front shapes.  the rounded tip of the projectile will result in less drag than the blunt tip.  increasing the slenderness of the rear part of the projectile reduces the coefficient of drag and for supersonic velocities the optimal length of the rear part is between 0.5 and 1 caliber.  the optimal value of the rear cone angle, at supersonic speeds, is 7. in the ansys fluent software package, based on a theoretical consideration of the supersonic projectile flow, a system of equations is chosen to describe the flow of air around projectiles. the domain in which the calculation is performed has been defined and boundary conditions have been set. from the offered software options for solving equations, the solving model was chosen and for each simulation the initial conditions were defined. before num. simulations for projectiles, the model was verified based on the aerodynamic drag coefficients of the sphere for different flow velocities. analysis of the influence of projectile geometrical characteristics on the drag coefficient at zero yaw angle was performed based on the results of numerical simulations. they are simulated for 5.56 mm projectile, ss109, m855, l110 and m856 models. these projectiles have similar outer shape: front part in the shape of a secant, cylindrical part and end part. they differ in the slenderness of individual parts of the projectile, in the slenderness of the whole projectile, by the radii of the ogive, by the shape of the rear part of the projectile. for each of the projectiles, 7 simulations were performed for ma = 1.2; 1.5; 1.7; 2; 2.5; 2.64 and 3. the greatest influence on the drag of the projectile has the shape and slenderness of the front part of the projectile; 5.56 mm ss109 and m855 projectiles have lower slenderness compared to projectiles 5.56 mm l110 and m856. regardless of the slenderness and how the ss109 and l110 projectiles are different they show similar aerodynamic characteristics in terms of the influence of their shape on drag; subsequent analysis of the results concluded that these two projectiles in some parts of the supersonic regime have the same drag. the drag analysis showed that the ss109 and l110 projectiles have less drag compared to projectiles m855 and m856. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] s. janković, aerodynamics of projectiles, faculty of mechanical engineering, belgrade, 1979. [2] anderson, j., modern compressible flow, mcgraw‐hill publishing, singapore, 1990. [3] mccoy, r., modern exterior ballistics: the launch and flight dynamics of symmetric projectiles, schiffer publishing ltd, 2nd edition, pennsylvania, 2012. [4] blazek, j., computational fluid dynamics: principles and appications, elsevier science ltd, oxford, uk, 2001. [5] sabanovic t., “analysis of influence of projectile shape on its drag coefficient for 5,56 mm ammunition using cfd”, mechanical engineering faculty, university of sarajevo, 2021. microsoft word 63-78_170.docx issn 2744-1741 defense and security studies original research vol. 2, may 2021, pp.63-78 https://doi.org/10.37868/dss.v2.id170 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 63 impact of industry 4.0 on aerospace and defense systems nedim tabaković1, benjamin duraković2* 1 software engineering, international university of sarajevo, bosnia and herzegovina 2 industrial engineering, international university of sarajevo, bosnia and herzegovina *corresponding author: bdurakovic@ius.edu.ba © the author 2021. published by arda. abstract the aim of this article is to address key features and the wave of new technologies that industry 4.0 brings to aerospace and defense systems. this research paper enthusiastically depicts what the future of the aerospace and defense industry could be while also providing information about those braves enough to already step into the world of all around digitalization. with this approach, the aim is to interconnect every step of the operation towards creating a mostly perfect environment which cuts off any human mistake and guarantees increase in revenue stream and customer satisfaction. the main method of implementation of industry 4.0 to many industries is digitalization. digitalization is the digital upgrade to any company or industry which, when applied correctly, guarantees nothing but success in revenue streams and customer service. this process is a complex blend of many modern technologies and implementing such a hefty upgrade might be problematic to those who have been surviving on very old business models for tens of years. industry 4.0 is a fast-changing environment and those who are quickly adapting to this wave of change are setting themselves for success. the primary goal of this research paper is to provide an insight into the world of technology industry 4.0 offers and how that technology could help aerospace and defense create a portal to the future. keywords: industry 4.0, technology, aerospace and defense systems, iot 1. introduction industry 4.0, otherwise called as the fourth industrial revolution represents a step into the future of human kind. with built-in sensing systems in nearly all industrial materials, goods, and facilities, industry 4.0 allows the manufacturing field to become digitalized [1]. from product development and buying through production, shipping, and service, industry 4.0 digitizes and integrates activities vertically throughout the whole organization. all data on operations processes, process efficiency and quality control, as well as operations planning, is available in real time, supplemented by augmented reality, and optimized in a network [2]. the fourth technological revolution is now underway in human society. it's said to be the next big thing, revolutionizing human relationships, thinking, and, most importantly, working [3]. industry 4.0 is a manufacturing system that combines operational technology (ot) with information technology (it) [4]. but fortunately, countries do meet those requirements, and many are still, slowly, but surely going towards that goal of digitalization. dss vol. 2, may 2021, pp.63-78 64 figure 1. industry 4.0 market the overall implementation and usage industry 4.0 is divided into three categories. horizontal integration is the first. it introduces the idea of a new kind of global supply chain network. vertical integration is the second. the idea is to create hierarchical subsystems on the production line in order to create a line that is simple to configure and flexible. the final aspect is engineering convergence across the entire supply chain, from beginning to end, to aid in product customization [5]. industry 4.0, as on many other things, has a great impact on defense systems. industry 4.0 is based on the digital transformation of processes and in the means of defense systems – the complete automation of drones and other defense systems. as a result of industry 4.0, the whole business is already seeing benefits from taking human error out of the equation. artificial intelligence and such technological advancements might pose an improvement in other fields, but as for aerospace and defense systems it poses some ethical questions which come in play when we think about all of the possibilities of automated technologies in defense systems. as we know, the whole world is leaning towards digitalization of every aspect of our lives. although some can precipitate this as an attempt to “upload” the whole planet to computers and a way for some higher power to control our everyday lives, industry 4.0 actually represents an attempt at somewhat perfecting every possible process (with sensors and internet connectivity). for customers who depend on those processes, industry 4.0 represents the perfecting of their customer service. industries overall are experiencing an increase in customer complaints, quality standard pressure, time precision, etc. so, we can just imagine what an impact industry 4.0 has had on aerospace and defense systems which already are almost perfect in every way. applying such a broad change to the whole industry is not an easy task and as such couldn’t be done in a few simple steps. instead, industry 4.0 is implemented through the entire makeover of a company network. however, all of those steps can be organized into reworking connectivity, customizability and intelligence. reworking connectivity means the entire communication structure previously defined. being well organized and in touch, a company really becomes a living breathing creature. the ecosystem of one company blooms, rewarding its budget and schedule. but, being in industry 4.0, companies are all interconnected, which helps take off the industry to a whole another level. such changes are done by introducing digital threads. a digital thread is the communication framework which guarantees connected data flow, smarter integrated structure and smarter ecosystem [6]. as previously said, such changes are done by implementing many core changes to how the system already operates which means integrating a software platform which is used by the whole of the operation. dss vol. 2, may 2021, pp.63-78 65 pros of including such a system are:  interconnectivity of the company and supply chain,  better customer and customer complaint and request management,  manufacturing and workforce efficiency increase,  reworking customizability. this digital thread approach has already shown some results in the form of efficiency growth at about 16% [7]. the digitalization of one company or company supply chain is not an easy task but brings a lot of room for financial growth and better overall connectivity. digitalization consists of many things such as: internet of things iot, augmented reality and virtual reality, large data processing, cloud computing, cyber security changes and much more. this just goes to show on that implementing such a system is not an easy task and consists of a lot of steps. however, companies which catch on early on this train of industrial revolution are already setting themselves up for success, as the results show. an overall name for this change is “digitalization” and apart from the already mentioned features, it brings many more features which will be mentioned later on in the text. figure 2. a visual representation of all of the improvements and features industry 4.0 brought [6] in theory, all of the features industry 4.0 brings should help every aerospace and defense company reach higher success and acquire remarkable financial goals, however, in reality things are a lot different. despite all of the excitement industry 4.0 brings to all industries, the reality is different. due to many reasons like digital illiteracy and lack of financial support, companies are forced to abandon the idea completely or settle for less rewarding results and minor changes. about 3% of all digital transformation initiatives within the aerospace and defense industry were succesful, 29% initiatives failed completely and 69% of initiatives settled for “suboptimal” results [8]. unfortunately, the technology might be too advanced to grasp in this exact moment but we believe it is progressing by day. of course, setbacks like lack of financial support cannot be avoided, but company owners getting educated on the issue of digitalization is mandatory. a chance like such is not something to be ignored and companies that succeed in their intention of digitalizing their bussiness model are probably going to be greatly rewarded in the near and far future. in the next section we will discuss some issues and challenges which make the process of digitalization a struggle for many companies. dss vol. 2, may 2021, pp.63-78 66 2. challenges and issues 2.1. digital illiteracy of company owners as a lot of companies are owned by corporation which is digitally illiterate, most attempts of implementing new technologies at such companies result in failure. indeed, 70 percent of corporate digital transformation programs fail due to a lack of digital literacy or awareness. a notable illustration of this appears to be the leadership of a&d defense corporations [7]. this could present a great problem for those companies as industry 4.0 is a fast moving change and taking early position in it could result in greater outcome. adapting late to change could cost those companies a lot of money or even the survival of the company. so, for a company to survive today’s climate, it needs to be digitally literate [8]. 2.2. lack of financial support from corporation of course, this is tied closely to the digital illiteracy part. digitally illiterate corporation might not realise how important it is to accept changes and to invest in industry 4.0. time is a very important factor in industry 4.0, as mentioned before, and by missing the chance to incorporate it into the whole system and defying the boundaries could cost these companies a lot of money. figure 3. overall interest in the aerospace and defense (marked maroon red) by us investors from 2005 to 2018 [9] overall investment in aerospace and defense r&d by us investors from 2005 to 2018 is presented in figure 3. in the us most of the research & development investment were made by business [55], as shown in fig. 3. air travel is becoming more popular, thanks to a rising middle class in emerging nations, millennial aspirations, and lower prices. the use of digital technology to match customer expectations will be critical to seizing this opportunity. these expectations have been formed in part by experiences in other industries, such as retail and entertainment, and today include more streamlined and integrated purchase trips, seamless travel, and customized, on-demand services [10]. now, for a company to be successful in this wave of industry 4.0, they need to be ready to complete some prerequisites. to be able to keep up with the new age of technology and industry evolving, companies need to be ready to accept changes and to easy conform to any changes. dss vol. 2, may 2021, pp.63-78 67 figure 4. three levels of digital transformation at aerospace and defense enterprises [54] figure 4. shows a digital transformation (digitalization) visualized by deloitte insights in three levels which companies must surpass to digitalize their business and work organization. these are three more goals of what the digital thread is trying to achieve: new services, enhancing customer engagement and making assets intelligent and interconnected [54]. 3. changes company giants which had a steady up rise during a long period of their existence and are used to a more traditional approach are being shaken up by newcomers who rely on the new industry strategies. this is why, by the standards of industry 4.0, change is better for those who are ready to accept it. between those changes, we need to give importance to following. 3.1. being agile between industry 4.0’s main improvements, one worth mentioning is being precise and agile, especially in the manufacturing sector. in aerospace and defense, such is accomplished by taking the traditional approach of manufacturing (physical and system testing) and amping it up to meet the customer needs. for example, in september 2018, the number of aircrafts reached the highest peak in 9 years. to be prepared for such speed of manufacturing and delivering, companies are starting to implement newer techniques towards keeping up with the newfound competition. the company under the name of airbus joined a research program founded by the eu, called ramp-up. this program is built for aircraft companies to research new technologies and develop better strategies to be able to fulfill all customer demand. airbus initially tested the manufacturing process according to the rampup program and found that the cost of the new materials and techniques actually cut off in half in contrast of their previous manufacturing cost [11]. 3.2. redesign of current business models since industry 4.0 heavily relies on the use of new technologies, sensors and data measuring devices being a part of them, using the collected data may be the only way to advance in today’s age. by recording customer feedback as well as any other possible technical and or financial information, by molding their new business model by these new parameters, the company is set for success as they provide only what makes them grow. for example, the aircraft manufacturing company boeing recently developed their data collecting program called “analytx” which is consisted of customers exploring and traveling their data-based travel plans that deliver information about fuel efficiency and notable operational setbacks. [12] dss vol. 2, may 2021, pp.63-78 68 3.3. supply chain improvements by collaborating closely with vendors, aerospace and defense manufacturers are maintaining innovation and mutual collaboration towards the goal of sharing the best strategies and practices for fulfilling the new challenges of the supply chain. the manufacturers accomplish this by using digital design, integration and simulation. this way, they don’t need to spend unnecessary time on prototypes. by supplying this information to the supply chain, the supply chain becomes transparent and visible which speeds up the whole process. in other words, all companies, being it manufacturing or part supply vendors, need to work together towards a great goal. boostaerospace, a supply chain between the european aerospace and defense manufacturers is an example of this. they provide any information needed between all suppliers, them being underdogs or well-known manufacturers [13]. the art and science of managing physical, financial, and information flows from the production of raw materials to end customers is known as supply chain management. two current trends pose a threat: 1. changes in information technology are permitting better coordination and analytical evaluations as a result of globalization; 2. globalization necessitates managing increasingly complicated and geographically distributed flows [14]. 3.4. cyber-security challenge with all of this, being private earlier, now being shared between companies via clouds and the internet, they face the new risk of their cyber-security being scrutinized. cyber-security issues present a great threat and a setback in these companies progress towards being by all means industry 4.0. so, protecting or intellectual property and ensuring the safety of the data being shared, companies needed to form cyber-security operational centers (csoc). the main goal of these centers is to detect threats, collect intelligence, respond to incidents, form a team of digital forensics, and monitoring and possibly avoiding cyberattacks [15]. the current problem for the a&d industry is two-stepped. first, the industry must endeavor to stay two steps ahead of the cyber danger rather than simply one. they need to keep investing in new capabilities, technologies, and concepts. they must remain attentive in the face of a danger that is exceedingly adaptable. they also need to put a greater emphasis on building security into their goods from the start. at the same time, a&d players will need to guarantee that any weaknesses in their present cybersecurity posture are filled [16]. 5.5. industry 4.0 inspired system aerospace & defense 4.0 is the application of industry 4.0 technologies in the a&d industry for developing new cost-effective products and services, making existing products smarter using sensors and connectivity, and leveraging advanced manufacturing processes such as additive manufacturing, among other [17]. creating a sustainable, inner-connected system based on cloud technologies, big data, internet of things (iot) etc. is also referenced as creating a “digital thread”. a digital thread is a system which is consisted of every possible work aspect of one company which are connected and relying on each other. figure 5. loop diagram of a never-ending cycle of one’s product manufacturing [18] dss vol. 2, may 2021, pp.63-78 69 each section is interconnected and does its own part towards serving the customer. every branch is interconnected and works like a living breathing creature. the flow of information in these kinds of structures is the most important factor, and the digital thread is a perfect, never-ending loop of information [18]. 4. features and improvements of industry 4.0 4.1. being efficient productivity growth is at the heart of every industrial revolution. previous industrial revolutions had a significant impact on the manufacturing process itself. companies increased their production by using the steam engine, electricity, and the transition from analogue to digital technology, for example. the fourth industrial revolution, on the other hand, has a broader impact, affecting not only production but other indirect departments, particularly engineering processes. that indicates that improving brainwork and decisionmaking processes has the greatest potential for increasing productivity. this process can be accelerated with collaboration at all levels [19]. for a&d, digitalization means the improvement of already well-established systems. companies which choose to implement industry 4.0 in their processes, benefit from not having to manually and physically test their products. they can instead test their products with simulation software which cuts costs and guarantees time efficiency. for example, the company “airbus” which is a manufacturer of aircrafts, decided to conduct simulations for the assembly of their “a350” aircraft to ensure that the new design and new more advanced materials do not result in unnecessary cost. the result has shown that the cost of the whole development was cut in half compared to competitor companies [20]. 4.2. new business models companies can use all of the sensor and system information gathered towards creating new business models which are more efficient, cost less and create better customer service. it would take a lot of time to create a business model from the data gathered, but using software, the issue is solved in minutes and business models are created overnight. in terms of a&d, companies might use data collected to create more efficient fuel economy, organize flight plans which suit more customers etc. new enabling technologies like big data, cloud computing, collaborative robots, additive manufacturing, artificial vision, or augmented reality are being introduced solely to improve the value creation architecture (key resources and activities) by increasing efficiency and improving performance (reducing costs, time, and failures, employee training, and so on). this might be the first step toward traditional industrial enterprises adopting industry 4.0 without taking on significant risks [21]. 4.3. supply chain and logistics changes companies can achieve optimal productivity and cost savings by establishing supply chains that are much more effective and do not depend on humans using high-performance quantum computing. this means that this technology can reduce errors (particularly human errors) and improve logistics and inventory management. this type of technology will take the form of a portal that manufacturers and vendors can use. a network called "airdesign," which is a platform for collaborative creativity in the a&d industry, is an example of this technology [22]. 4.4. cyber security improvement until recently, cybersecurity was primarily concerned with defending organizational perimeters, that is, preventing illegal access to a privately owned computer network. to protect the perimeter from hackers, the most common technique was to install safeguards such as firewalls, intrusion detection systems, and virus protections at the perimeter's entrance. as industry 4.0 blurs the lines between the real and digital worlds, this cybersecurity approach is quickly becoming obsolete. similarly, communication technology, in combination with social and cultural considerations, are altering working patterns in the direction of "anywhere, anytime" [23]. for a&d companies, security and cybersecurity is something very important. with the introduction of industry 4.0 and digitalization, companies are more exposed to risk as the data they now digitally store could potentially be harmed. this calls for the betterment of their security systems which automatically improves dss vol. 2, may 2021, pp.63-78 70 the overall security of one company. in other words, because digitalization poses a possible challenge and an issue with cybersecurity, companies spend more time designing a better cybersecurity system which protects everything. as the need of creating strong levels of digital trust grows, so does the relevance of transparency and nonrepudiation, which provide verification of the integrity and origin of one's own and third-party data. strong risk management and data integrity solutions can help businesses avoid breaches and effectively manage operational disruption [24]. 5. industry 4.0 methods many industry 4.0 technologies could support the aerospace and defense industries. however, while not every invention or method would be useful in the long term, they all have the same function of interacting with one another to form a "world ecosystem" [25]. as it was mentioned earlier, digitalization is consisted of many features which work together towards a better goal. methods of industry 4.0 that can be used for aerospace and defense systems following. 5.1. internet of things there are over 20 iot characteristics that can complement and add benefit to aerospace systems in a variety of ways, including reducing consumer pain points including flight termination and delays, but the most important ones are:  interconnectivity interconnection is maintained when all of the sensors and systems are interconnected via internet [26].  things-related services within the limits of things, such as privacy protection and semantic coherence between real and virtual things, the iot can provide thing-related services. both the physical and information world technologies will have to alter in order to deliver thing-related services within the restrictions of things [27].  heterogenity the iot devices are heterogeneous, since they are based on many hardware platforms and networks. through various networks, they may communicate with other devices or service platforms [28].  dynamic changes device states, such as sleeping and waking up, being connected and/or disconnected, and the context of devices, such as location and speed, alter dynamically. furthermore, the number of devices might fluctuate.  enormous scale the number of devices that will need to be controlled and interact with one another will be at least an order of magnitude greater than the existing internet's gadgets [29].  safety the obligation to preserve the legitimate interests of users and the integrity of the ecosystem that links them is implicit in the freedom to innovate. this is especially true when the internet expands into physical areas and the availability of next-generation technologies and artificial intelligence grows [30].  connectivity connectivity is self-explanatory. through industry 4.0, everything and anything is interconnected and that greatly helps towards building a massive, breathing and living system which can ease the process of manufacturing and getting information by a great margin [31,32,33]. 5.2. big data analytics big data is a modern wave of technology and architectures that are developed to derive value from massive data volumes with a wide range of data types, enabling real-time computation and analysis. the "digital plane" of today, which can capture up to 300,000 parameters based on the length of the flight and the type of aircraft, is a direct example of big data's effect on the aerospace industry. according to one big aircraft maker, data sharing will grow by 14% in the next few years [34]. the phrase "big data" refers to the development and application of technologies that offer the appropriate user with the right information at the right time from a massive amount of data that has been expanding dss vol. 2, may 2021, pp.63-78 71 exponentially in our society for a long time. the issue is not just dealing with fast expanding data volumes, but also handling more varied forms as well as increasingly complicated and interlinked data [35]. simulation – as expected, simulation is up there with the most important innovations and techniques of industry 4.0. simulation may be used to test product designs, systems, and device configurations. simulating risky flight conditions, like all other facets of aviation, can be done by simulation. simulators are particularly well suited to training scenarios that are inefficient, impossible, risky, or costly to replicate in a live setting. many potentially risky conditions can only be encountered infrequently by aircrew. if these circumstances arise, they must be dealt with quickly in order to prevent drastic repercussions. simulators may be used to expose trainees to certain unique conditions in a repeatable and controlled way, with little danger to the pilot, aircraft, other operators, or the environment [36]. simulation has become a significant technique for supporting and developing a wide range of systems in the twenty-first century. simulation has enormous promise for the creation and enhancement of products and industrial processes. simulation is a potent and well-known methodology for addressing the manufacturing industry's present difficulties. industrialized nations frequently struggle to maintain the expanding industrial sector within their borders. new manufacturing plants are being created from the ground up to conform to the trend of mass customization over mass production while enhancing profitability [37]. 7.3. augmented reality in the aerospace and defense industries, augmented reality will aid engineers in the development of new technologies as well as the improvement of existing systems by including 3d graphics of drawings and simulations for whatever is being designed. the aim of this category is to make guidance easier to interpret if they were available as 3d models superimposed on the real equipment demonstrating how the activities are to be performed step-by-step with illustrations to make the directives ever more clear [38]. overall, the usage of augmented reality in the industry domain is very important because it greatly improves communication in product design and production development: it aids in the early detection and avoidance of design errors; it reduces the number of physical prototypes and saves time and money for businesses. in many industrial applications, augmented reality is seen as a beneficial tool for enhancing and speeding up product and process development [39]. figure 7. augmented reality organization [40] figure 7. is a visual representation of an augmented reality work organization between workers, the data (sensors, cameras, internet of things iot), the presentation of the data (overlays, audio cues and live representation) and the interaction with the data (gestures, voice commands, gaze and attention). this all results in an environment which takes use of augmented reality [40]. 5.3. advanced analytics (for monitoring real-time aircraft health and identifying system failures in advance) the continual rise of the aviation sector has produced a highly competitive environment in which airline businesses are trying to stay afloat in a market with poor profit margins. consistently more rigorous maintenance schemes have resulted in an increase in aviation safety, despite increasing expenses. to stay competitive, airlines are decreasing total cost by running their operations as smoothly as possible. as a dss vol. 2, may 2021, pp.63-78 72 consequence of technological improvements in the business, the availability of flight data has risen, causing airlines to monitor their fleet's behavior more thoroughly. the aircraft's systems gather flight data, which is then decoded and transmitted to the engineering, maintenance, and safety departments for interpretation and analysis [41]. 5.4. digital reality (replacing assembly manuals with smart-glasses) body-tracking and motion-tracking capabilities are core features, allowing a user to manipulate and move objects using haptic controllers, head-mounted displays, and headsets [42]. such technologies can be used for manipulating assembly manuals and instructing assembly workers on creating aero systems and machines as well as for many other uses. figure 8. integration of digital reality in assemblies / manufacturing processes [43] figure 8. shows different ways of digital reality integration into assemblies and manufacturing processes by worldwide companies. it can clearly be seen what can be accomplished with use of some kind of headwear which projects information associated with a part in the machine [43]. computers, processing power, the internet, cloud computing, and the internet of things are all part of the fourth industrial revolution. virtual reality is used in industry 4.0 to reduce design and manufacturing costs, maintain product quality, and solve technological tradeoffs such as decreasing rendering complexity while maintaining high refresh rates or improving resolution while maintaining a stable vr experience. virtual reality is an undeniably unique tool with numerous applications, ranging from teaching students all over the world to simulating safety scenarios. however, it must be integrated with viable use case scenarios and realtime data collection in order to capture physical movement and provide a pleasant vr experience [44]. figure 9. digital reality [45] digital reality center of gravity business developm ent market investments and strategy talent and loction corporate developm ent conferences and events marketing and activation eminence value chain vendors prototypes dss vol. 2, may 2021, pp.63-78 73 figure 9. shows al of the opportunities digital reality creates as the center of its own solar system. many scientists and scholars agree that a system like it can create many opportunities for a lot of people of the world. it is the center of gravity for many industry branches, events, investments, ideas and eminence [45]. 5.5. autonomous robots autonomous robots are robotic systems which demand no human interaction or effort other than building them and can be used for many actions in aerospace and defense, basically any physical action a human can do, a robot can replicate. currently, many companies that use autonomous robots have implemented them for targeted functions within their supply chain, piloting various robots to verify expected efficiency gains. as innovative companies grow and expand operations, robots that build robots could be the norm for economically and efficiently optimizing manufacturing operations [46]. intelligent automation has a history in the a&d sector, including so-called "smart" weaponry developed by top-tier military and space missions powered by modern technology. the creation of new and interesting methods to add value to domestic and global a&d supply chains will continue to be driven by that inventive attitude [47]. 5.6. cloud computing cloud computing is a system that provides usable information within a certain company, workspace or organization. cloud computing offers flexible access to computing resources, providing both efficiencies and challenges to the aerospace industry where proprietary information not only is business critical but also can be a national security risk if exposed inappropriately [48]. nitha rachel shows how cloud computing is utilized to host services on a ground station, which subsequently gives services to airplanes passing through the area. a vm (virtual machine) will be relocated from one node to another node on a different cloud in a new geographical region when an aircraft transfers from one geographical network to another. it also defines an aviation data network with a virtual private cloud that uses an ipsec connection to deliver cloud services [49]. 5.7. additive manufacturing additive manufacturing is a process of printing certain parts of a mechanical system, otherwise known as 3d printing. additive manufacturing (am), is a manufacturing technique that builds objects layer by layer using materials such as polymers, metals, and composites. figure 10. additive manufacturing process figure 10. shows a visual representation of the process of additive manufacturing, also known as 3d printing in which the manufacturing of a turbine goes through 5 steps towards its completion. it firstly is designed in cad software, then it is processed to a .stl file, the layers are sliced and sent into the am system in which it is printed and lastly assembled [50]. 5.8. industrial internet of things industrial internet of things is a technology dealing with the interconnection of physical devices along with inter-relation of data via internet without requirement of human to machine or human to human interaction. as internet of things (iot) it can be used for manufacturing aero systems and by doing it this way, errors and especially human errors could be avoided efficiently. by connecting devices and data, iot presents opportunities for organizations to transform themselves, gain entry into new markets, and harness data to drive more timely and powerful business decisions [51]. cad-based 3d model *.stl file sliced ayers am system end part finishig final product dss vol. 2, may 2021, pp.63-78 74 applications in the following sectors may have the greatest immediate effect from industrial iot from these features: • bringing together information from suppliers, logistics providers, and customers; • data from new technologies, peripherals, tools, and equipment are introduced; • production in a distributed environment requires adding of additional data sources, locations, and owners; • raw materials, parts, goods, and orders going through organizations are all equipped with sensors [52]. 6. quantitative diagrams of industry 4.0’s usage figure 11. usage of industry 4.0 technologies and features by aerospace and defense companies in 2017 figure 11. shows a quantitative value of the usage of industry 4.0 technologies, features and services by all of aerospace and defense companies in 2017. it encompasses following:  77% augmented reality – used for sales and marketing (interaction with customers),  63% artificial intelligence – used for collecting product sales and customer usage data,  57% virtual reality – used for design techniques, walk-ins and tutorials,  57% blockchain technology – used for managing configuration data [53] . due to many aviation companies implementing digitalization into the core of their systems in industry 4.0, we can see the “boom” industry 4.0 made in 2015. figure 12. profit due to digitalization in the aviation industry in period 2010 2021 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% augmented reality artificial intelligence virtual reality blockchain technology dss vol. 2, may 2021, pp.63-78 75 figure 12. shows a worldwide profit due to digitalization in the aviation industry 2010-2021 as collected from icao.int, the uniting aviation united nations specialized agency. consumer expectations are changing all across the world as a result of digitalization. because of its speed and size, businesses must rethink and reinvent their customer experiences in order to keep up, including new products, applications, and technologies to improve customer interactions [53]. 7. conclusion in conclusion, a new wave of amazing and future-promising technology is something aerospace and defense companies are striving to achieve. these features are built to ease the process of manufacturing, customer service and financial growth and many companies recognize this. the cost of manufacturing significantly drops, customer service feedback is great and the financial growth is incomparable to that of older business models. but, for some companies, trying to navigate new technologies and business models doesn’t go to plan. converting to this new form of business, which lies on the platform of digitalization, is not an easy task. for a company to succeed in its attempt to digitalize, there are some unavoidable factors which need to be fulfilled. so, we believe, the issue is not in the new technology, but in humans running these operations and feeling comfortable with what they possess right now. old business models are efficient, but not enough, and not for long, as virtually everything now relies on those principles listed earlier: manufacturing efficiency, customer service and financial growth. this technological revolution, on its own, possesses a great opportunity for those ready to take a leap and risk what they have to conform to change, and companies which are ready to step out their comfort zone should be greatly rewarded in the future, as a technological future is inevitable. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] s. i. tay, t. c. lee, n. z. a. hamid, and a. n. a. ahmad, “an overview of industry 4.0: definition, components, and government initiatives,” j. adv. res. dyn. control syst., vol. 10, no. 14, pp. 1379–1387, 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[55] b. durakovic and e. trgo, “perspectives and the role of bosnian defense industry in national innovation system,” defense and. security studies, vol. 1, pp. 26–33, apr. 2021, doi: 10.37868/dss.v1.id145. microsoft word 113-120_217 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.113-120 https://doi.org/10.37868/dss.v3.id217 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 113 biodefense against abrin and ricin as bioterrorism agents a virtual screening of indonesian plant medicinal properties leni tria melati1*, timbul siahaan2, i nengah putra apriyanto3 1,2.3 faculty of defense technology, indonesian defense university , indonesia *corresponding author e-mail: leni.melati@tp.idu.ac.id1 received: dec. 8., 2022 revised: dec. 14., 2022 accepted: dec. 21, 2022 online: dec. 25, 2022 abstract because of their high lethality and easy way to produce, abrin and ricin are often used as bioweapons. sources of raw materials for the abrin and ricin manufacture can be found in various regions, especially in tropical countries. those make abrin and ricin have a greater chance to be used as bioterrorism agents. furthermore, abrin and ricin have been classified as class b types of bioweapons used in bioterrorism. in this study, a virtual screening (a bioinformatics method) will be carried out on 100 compounds derived from indonesian plants. thus it can be known, the compounds that have the potential to be used as biodefense agents against abrin and ricin. finally, it is found that there are five compounds that have the best possibility as abrin inhibitors: procyanidin b4, ursolic acid, corilagin, vulgarin, and gliberelic acid. whereas lanuginosine, xylonine, isovitexin, liriodenine, and procyanidin were found to have more potential as biodefense agents against ricin. © the author 2022. published by arda. keywords: abrin; biodefense; bioinformatic; bioweapon; ricin 1. introduction biological weapons are considered to be very detrimental and difficult to control so all forms of manufacture, development, and the usage of bioweapons in war have been prohibited since 1925 in geneva law [1]. even so, there are still several cases of violation of these regulations by certain groups such as terrorists [2]. even today, the use of technology such as genetic engineering provides opportunities for the development of biological weapons to a further level [3]. bioweapons have actually been used for a long time in various forms of biological warfare. it is noted that the use of bioweapons has been started since medieval times. where in 1340, the corpses of horses or other animals affected by the plague were being thrown using a launcher to the enemy groups, so it would cause a widespread of said disease within the enemy troops [1]. this shows how easy it is to develop and use bioweapons, even with only such simple equipment and materials. the usage of biological weapons by terrorists is considered to result in high mortality rates as well as economic, social, and political losses [4]. this is because biological weapons are difficult to detect early on and their spread cannot be completely controlled (except for poisons), and these weapons may even attack the user himself [1]. according to one of indonesian military observer, bioweapons are widely used because they dss vol. 3, 2022, pp.113-120 114 are cheaper and more effective [5]. one of the bioweapons that are widely used by terrorists is abrin and ricin. abrin and ricin are ribosome-inactivating proteins (rips), which come from the abrus precatorius plant that is easily found in tropical areas, especially in southeast asia [6]. in fact, due to the level of toxicity and ease of preparation, the two toxins are in category b as agents of bioterrorism [7]. in 2011, a militant group in jakarta, indonesia, was found to have attempted to attack the police using ricin. in 2019, the indonesian police succeeded in seizing a bomb containing abrin poison from a raid on the largest pro-islamic state terrorist group in indonesia [8]. in regards of these matters, it is necessary to have a strong defense against bioweapons (biodefense) within a country. as the united states (us) learned from the bitter experience, of the bioterrorism case that occurred in 2001, and increased research efforts in the field of biodefense in their country [9]. the drug discovery process (in this case as biodefense agents) often takes a long time and requires a lot of money. the implementation of bioinformatics (in silico approach) provides a very significant influence in drug development. this approach provides a more effective and cheaper process. through an algorithmic simulation, accurate and fast research results can be obtained and only require a small fee [10]. furthermore, bioinformatic has also been widely applied and closely related to biodefense [11], bioterrorism, and bioweapon research such as the bioweapon identification, detection (biosensors) development, as well as the development of vaccines and drugs from bioweapons [12]. this research aimed to identify plant-derived compounds that are commonly found in indonesia as ricin and abrin inhibitors. the identification process is carried out by virtual screening method (bioinformatics procedures) based on molecular docking virtual simulations [12]. 2. research method 2.1. receptor preparation target receptors, namely ricin [13] and abrin [14], were downloaded from http://www.rscb.org/pdb. the target receptor preparation process was carried out using the pymol 2.5 software by schrödinger. the geometry optimization process uses pymol software. the initial step is the removal of water molecules (h2o) around the receptor, hetero atoms, and natural ligands. next is the addition of gasteiger and hydrogen charges. the receptor and its natural ligand are separated (extract object) and each is stored in pdbqt format. 2.2. inhibitor preparation a list of 100 compounds derived from plants in indonesia can be obtained on the following link: http://herbaldb.farmasi.ui.ac.id/v3/. these compounds (inhibitors) can be downloaded from the https://pubchem.ncbi.nlm.nih.gov/ page. the inhibitor compounds were then optimized using openbable gui 3.1.1 software and saved in pdbqt format. so that the ligands can then be used in the virtual screening process. 2.3. virtual screening the virtual screening process is carried out through a simulation process of combining receptors and their inhibitors using the autodock vina software [15]. as a result, the value of binding affinity or the tendency for binding between the ligand and the receptor protein will be obtained. thus it can be determined which compound has the best binding affinity at root mean square deviation (rmsd) 0.0. of all the compounds, 5 compounds that give the best results will be taken to be further visualized and analyzed. 2.4. visualization the virtual screening results were visualized in 3d graphics using pymol 2.5 (by schrödinger) and 2d graphics using ligplot+ version 2.2 (by embl's european bioinformatics institute). furthermore, the results of the visualization can be used for the process of analyzing the inhibitory abilities of the selected compounds. to assist the analysis process, a binding site prediction of the receptor will be carried out on dss vol. 3, 2022, pp.113-120 115 https://prankweb.cz/. thus, based on the results of 2d visualization, comparisons can be made to find out whether the selected compound binds to the target binding site so that it can be a good competitive inhibitor and thus can be used as abrin or ricin antitoxin. 3. results and discussion indonesia has an abundant amount of natural resources, particularly in the form of plants. some plants can produce secondary metabolomic compounds that have the opportunity to be developed as drugs. the screening process is carried out to filter metabolomic compounds from the database, which have the opportunity to become drug materials based on the virtual computing method [12]. the docking process is based on the binding activity of certain compounds (ligands/inhibitors) on the target protein. protein itself is the basic structure of all living things. knowledge of the proteins that make up an organism and understanding their functions is the basic foundation of molecular biology [16]. for this reason, protein is often used as the main target in drug or therapy development processes. based on the virtual screening results, out of 100 compounds, there are 5 compounds that gave the best binding affinity value at rmsd 0.0. the list of these compounds can be seen in table 1. the binding of each selected ligand to the target protein (ricin and abrin) was then visualized in 2d and 3d using ligplot and pymol software. previously, binding site predictions from ricin and abrin had been carried out, as shown in table 1. based on these predictions, it was possible to compare the 2d visualization results from virtual screening results for further analysis. table 1. binding site prediction results and five compounds that have the best potential as abrin and ricin inhibitors receptor binding site (residue) ligan / inhibitor pubchem id molecule abrin pocket 1 (a_111 a_112 a_113 a_159 a_163 a_164 a_167 a_195 a_196 a_198 a_199 a_244 a_71 a_72 a_74 a_75 a_87 a_89 a_90 a_91) pocket 2 (a_140 a_141 a_144 a_145 a_146 a_151 a_78 a_80 a_83 a_85) pocket 3 (a_170 a_190 a_194 a_219 a_220 a_221 a_236 a_239) 147299 [17] procyanidin b4 64945 [18] ursolic acid 73568 [19] corilagin 94253 [20] vulgarin 6466 [21] gibberellic acid ricin pocket 1 (a_100 a_104 a_120 a_121 a_122 a_123 a_172 a_177 a_180 a_208 a_209 a_211 a_212 a_256 a_258 a_48 a_75 a_78 a_80 a_81 a_82 a_93 a_94 a_95 a_96 a_97) pocket 2 (a_183 a_203 a_207 a_233 a_234 a_235 a_240 a_251) 97622 [22] lanuginosine 160503 [23] xylopine 162350 [24] isovitexin 10144 [25] liriodenine 122738 [26] procyanidine 3.1. virtual screening against abrin based on the results of abrin virtual screening, it is known that procyanidin b4, ursolic acid, corilagin, vulgarin, and gliberelic acid have the best potential as inhibitor. figure 1 shows the results of the abrin virtual screening 3d visualization in pymol 2.5 (by schrödinger). these results were then further processed ligplot + 2.2 (by embl's european bioinformatics institute) to obtain a 2d visualization of the virtual screening process that is shown in figure 2. this way we can understand the bonds and interactions that formed between each compound against abrin. dss vol. 3, 2022, pp.113-120 116 (a) (b) (c) (d) (e) figure 1. 3d visualization in pymol 2.5 (by schrödinger) to show the interaction between abrin and (a) procyanidin b4; (b) ursolic acid; (c) corilagin; (d) vulgarine; and (e) glibberellic acid as virtual screening result using autodock vina. (a) (b) (c) (d) (e) figure 2. 2d visualization in ligplot + 2.2 (by embl's european bioinformatics institute) to show the interaction between abrin and (a) procyanidin b4; (b) ursolic acid; (c) corilagin; (d) vulgarine; and (e) glibberellic acid as virtual screening result using autodock vina. dss vol. 3, 2022, pp.113-120 117 from previous figures, the procyanidin b4 compound appears to be bound to pocket 3 of the abrin binding site. there are amino acid residues (a) numbered 170, 194, 219, 220, 221, 236, and 239 which are around the procyanidin b4 compound. visualization results also show the formation of hydrogen bonds (green dash) and hydrophobic interactions between the inhibitor and the target receptor (figure 2a). meanwhile, ursolic acid, vulgarin, and gibberellic acid compounds were seen to interact with several amino acids in pocket 1 of the abrin binding site, through hydrophobic interactions and hydrogen bonds (figures 2b, 2d, and 2e). meanwhile, the corilagin compound does not seem to bind to one of the pockets on the binding site of abrin, so there are two possibilities, whether the compound is a non-competitive inhibitor or does not even have the ability to inhibit abrin. 3.2. virtual screening against ricin based on the virtual screening results for ricin, five compounds that had the best potential to be used as ricin inhibitors were obtained. these compounds are lanuginosine, xylonine, isovitexin, liriodenine, and procyanidin. the 3d visualization results (visualized in pymol) of the five compounds with ricin can be seen in figure 3. then the visualization process is continued with ligplot to obtain 2d visualization. in 2d visualization, it was observed that there was a hydrophobic interaction between lanuginosine and ricin compounds. the interaction occurs in pocket 1 of the ricin binding site. it can be observed that several amino acid residues (a) are involved in this interaction, including numbers 80, 81, 82, 93, 94, 121, 122, and 172. likewise with the other four compounds which also interact with ricin in pocket 1 (fig. 4). even the compounds isovitexin and procyanidin, managed to form hydrogen bonds (green dash) with some of the amino acid residues that make up pocket 1 (figures 4c and 4e). the interactions that occur at the pocket binding site on the protein receptors (ricin and abrin) indicate that these compounds have the opportunity to become competitive inhibitors for abrin and ricin. thus these compounds have the opportunity to be used as raw materials and further researched for the development of antitoxins for ricin and abrin, as a form of biodefense effort. (a) (b) (c) (d) (e) figure 3. 3d visualization in pymol 2.5 (by schrödinger) to show the interaction between ricin and (a) lanuginosine; (b) xylopine; (c) isovitexin; (d) liriodenine; and (e) procyanidine, as virtual screening result using autodock vina. dss vol. 3, 2022, pp.113-120 118 (a) (b) (c) (d) (e) figure 4. 2d visualization in ligplot + 2.2 (by embl's european bioinformatics institute) to show the interaction between ricin and (a) lanuginosine; (b) xylopine; (c) isovitexin; (d) liriodenine; and (e) procyanidine, as virtual screening result using autodock vina. 4. conclusions abrin and ricin are toxic compounds with high level of lethality that can be easily produced, therefore have a great chance to be used as bioweapons in some bioterrorism cases. this study conducted a virtual screening of 100 compounds derived from several plants in indonesia. from this virtual screening process five compound has been found to have the best potential for further research as raw materials for antitoxins against abrin and and another five for ricin. compounds that have the potential as biodefense agents against abrin are procyanidin b4, ursolic acid, corilagin, vulgarin, and gliberelic acid. while the potential compounds to become biodefense agents against ricin include lanuginosine, xylonine, isovitexin, liriodenine, and procyanidin. this research is based on the results of virtual simulations, so it is necessary to carry out further research using other tests to determine the effectiveness of these compounds as biodefense agents against abrin and ricin. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. dss vol. 3, 2022, pp.113-120 119 references and citations [1] v. s. georgiev, in national institute of allergy and infectious diseases, nih volume 2, humana press: springer nature switzerland ag, 2009. 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"pubchem compound summary for cid 122738, procyanidin b2", pubchem, https://pubchem.ncbi.nlm.nih.gov/compound/procyanidin-b2. 10 november, 2022, microsoft word 58-66-184 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.58-66 https://doi.org/10.37868/dss.v3.id184 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 58 utilization of disused airfields of bangladesh both during peace and war majidul haque bhuiyan 1* 1 department of electrical and computer science engineering, north south university, bashundhara, dhaka 1229, bangladesh *corresponding author e-mail: majidul.haque@northsouth.edu received: jun. 4, 2022 revised: sep. 13, 2022 accepted: sep.14, 2022 online: sep. 19, 2022 abstract airpower played a vital role in shaping the result of the second world war. as a british colony, the indian sub-continent was targeted by imperial japan. the japanese forces came up to myanmar (then burma) and their next target was the indian sub-continent. due to the geographical location, bangladesh (the then bengal) was on the front line of british defense; as it was strategically important for japan to occupy bangladesh. as such, bangladesh air space was highly contended by the belligerents. to support air operations, a good number of airfields were prepared by the british-led forces in the then bengal. however, after the war, most of those airfields were abandoned. british left the region in 1947 and bengal became part of pakistan. economic, strategic, and political factors did not permit the maintenance of those airfields and most were left as it was. only tejgaon airfield was used by pakistanis for both civil and military aviation purposes. after the independence of bangladesh in 1971, an effort was made to revive some of those airfields. © the author 2022. published by arda. keywords: airfields, bangladesh, economic growth, 1. introduction bangladesh is becoming economically stronger. with her economic growth, she needs a strong defense to ensure her sovereignty. to meet the future requirement, bangladesh is preparing its defense forces under the national guideline named vision -2030 which is also commonly known as forces goal2030. as per this, baf is going to have more combat and combat support units with the necessary aircraft and helicopters. the airfield is a very important element of air power. military power cannot be projected without airfield support. presently baf is operating from four airfields out of which three are civil airfields. the city traffic is increasing with the economic growth of the country day by day. it is becoming difficult for baf aircraft to operate from those joint airfields because of increased city traffic. this situation will be further complex as several civil traffic is on the rise. so it will not be possible to operate an increased number of baf aircraft from those airfields. as such, baf must look for alternate airfields for her future expansion. disused airfields are the best option as construction of a completely new runway is highly expensive and land scarcity in the country would it even more difficult. many british-built airfields still exist in bangladesh. in due course of time, a few of those are no more in existence, many of those are not in good shape due to misuse and lack of proper maintenance, but few are still in good condition. 2. research objective to recommend the feasibility of using disused airfields of bangladesh both during peacetime and wartime. dss vol. 3, 2022, pp.58-66 59 3. problem statement bangladesh has a limited number of active airfields. baf is operating with civil traffic in most airfields because of this limitation. this is becoming difficult to operate from those airfields due to traffic congestion. it hampers effective training, and the economy of effort and jeopardizes flight safety. the situation will aggravate in the future when the number of both baf and civil traffic will increase. bangladesh has many disused airfields. if baf takes over some of those airfields and maintains them to operable standards then it would be beneficial in case of the national requirement. this will also help baf to operate more effectively both in peace and wartime. the core issues with this research are disused airfields (independent variable) and utilization of those airfields by baf in peace and war (dependent variable). to search for a pragmatic solution to the problem statement, this research has been limited to the following questions. primary question is:what may be the peacetime and wartime utilization of disused airfields of bangladesh? secondary questions are: what is the baf's requirement for the airfield to meet the expansion plan as per forces goal-2030? and what are the airfields that may be developed for future requirements? 4. limitations and assumptions this research is mainly based on the primary data available from different sources and interviews with specialists. it is not possible to check the physical condition of those airfields which would give a better understanding of the present condition of those airfields due to time constrain and the scope of the research. 5. hypothesis bangladesh has had many disused airfields since world war ii. if baf takes over some of those airfields and maintains them, those airfields may be used for regular use, disaster management, or natural calamity. it will reduce the traffic congestion on the jointly operated airfields, provide effective and economical training to baf and promote flight safety. in wartime, this will provide good options for more operating surfaces, dispersal of the assets, and increased radius of action for friendly aircraft. 6. present state of airfields in bangladesh bangladesh is a small country with growing demand for land for industry and agriculture. in 2011 government planned to build a new airport at munshigonj (arial bill), which is a marshy land. but in the face of strong protest from local people, the government abandoned the project. the runway length of bogra airfield could not be extended as land could not be acquired yet. in light of this fact, it is very important to maintain the disused airfields not only for baf, but also to facilitate civil aviation and other national requirements. if disused airfields are renovated; civil airliners and any other agencies may also be benefited. this would improve responsiveness during times of natural calamities like floods and earthquakes. during wartime, the airfield is the platform from where military force can be projected through aircraft [7]. the existence of an active airfield and associated infrastructure is an additional factor in regional, social and economic development. it is a very costly affair to construct an airfield even if the land is available. present state of airfields in bangladesh: bangladesh possesses 43 airfields/landing strips. these airfields can be classified as operational airfields, stol ports, or disused and usable airfields. after independence, the country only developed a few airfields to meet the requirement [1][2]. out of all the available airfields, baf jointly operates with caab from all those airfields except tejgaon which is dedicated to baf operation (except fighters). baf also uses bogra for basic trainer aircraft and shamshernagar for limited air transport operations. cox’s bazaar airfield is fit for the emergency operation of baf jet aircraft. however, cox's bazar runway is likely to be extended by another 1,500 feet which would allow fighter jets to operate from cox's bazar. recently baf has signed an mou with caab, where baf is authorized to establish necessary installations around the barisal airfield and operate from there. 6.1 active/operational airfields in total 12 airfields are classified as operational; those are kurmitola (hazrat shahjalal international), tejgaon, chittagong, jessore, cox’s bazar, rajshahi, saidpur, sylhet, barisal, bogra, shamshernagar, and lalmonirhat. 6.2 stol ports there are three stol ports; comilla, ishurdi, and thakurgoan. dss vol. 3, 2022, pp.58-66 60 6.3 disused and usable airfields some airfields were used earlier during world war ii and are not in use now. these airfields have basic structures and more importantly, the land is not yet grabbed by locals. there are 15 airfields of this kind, which can be used for undertaking major or minor repair works. the following table shows the name of these airfields along with info. 6.4 disused and unusable airfields the remaining 13 airfields are not recoverable or unusable [4][5][9][10][11]. in this case, most of the operating surface is either damaged by the local population or in possession of land grabbers. 7. considerations for taking over a runway some factors must be kept in mind while taking over or making a runway operational. these are: 7.1 strategic considerations to establish a runway for military use, strategic considerations must be taken into account. this should include own vas, vps, enemy vas, vps, location of probable adversary's air bases, probable enemy avenue of approach, potential enemy’s capability, and other geopolitical considerations. 7.2 runway length a runway of at least 6,000 ft (1,829 m) in length is usually adequate for aircraft weights below approximately 200,000 lb (90,718 kg). baf should look for an airfield that can accommodate fighter aircraft [17][18]. as such the runway length should be 7500 feet or more for fighter operation. 7.3 availability of land to establish an air base, a lot of infrastructure development will be needed. this will require a huge area of land in and around the airfield. so availability of land is a concern for taking over an airfield. 7.4 topography there should be sufficient plain land in and around the airfield so that the approach and landing path are clear of obstacles. overrun areas are also constructed at the end of runways as emergency space to stop aircraft that overrun the runway when the landing may go wrong, or to stop the aircraft on an aborted takeoff. 8. threat perception bangladesh is a very small country thus the geographical depth is also very less. it is minimum aerial depth is 140nm in east-west and 213nm in the north-south direction. the map showing the geographical depth of our country is given as annex b. with a combat speed of 800 kph, a fighter ground attack aircraft can reach dhaka from the east in 5 min 25 seconds, from the north in 10 min 45 seconds [1], and from the west in 12 min 30 seconds [20][21][22][23][24][25][27]. attacking chittagong from the north will take 5 min 50 seconds. she is surrounded by the big neighbor india on three sides (for air power on four sides as indian naval air arm can attack from the south too). she has both a land and maritime border with myanmar. the probable threats from those two neighbors are discussed below: 8.1 air threat from india indian air force (iaf) is the fourth largest air force in the world. iaf's eastern air command (eac) would be the main threat to bangladesh. eac has 15 air bases in its aor. among these kolkata, barakpur, bagdogra, hashimara, baranpani, agartala, and kumbhirgram are located close to our border. eac has different types of fighter aircraft, such as mig-21, mig-23, mig-25, mig-27, mig-29, mirage-2000, and su-30. iaf is in the process of purchasing rafael, su-30 mki, and su t-50 within 2022. due to less geographical depth, we would get very less reaction time to encounter the air threat from eac [2][3][4][8]. indian naval aircraft carrier would be able to pose threat from the south and may block the sea lines of communication (sloc). 8.2 air threat from myanmar myanmar has developed a balanced air force. with the changed geopolitical situation, myanmar is becoming a more important factor in the region. this will lead myanmar to acquire a more capable platform dss vol. 3, 2022, pp.58-66 61 for military use. as of now, myanmar air force (maf) has around 132 combat aircraft including mig-29, a5c, f-7, g-4 super galeb, and k-8 [12][13][14][15][16]. maf reportedly has or acquiring the maritime version of mig-29 too. the maf quality of training and manpower skill is difficult to determine. with present capability, maf could launch a limited strike on chittagong and cox’s bazar and threatens our sloc and exclusive economic zone (eez) maf may utilize civil airfields as front-line airfields in case of hostilities. 9. peacetime and wartime use of disused airfields airfields may be used by baf for the following purposes in peacetime: 9.1.1 disaster management bangladesh is a disaster-prone country. whenever any natural calamity hits, relief operations are conducted. in case of any earthquake or massive floods, many of the airfields may become unusable. sometimes even relief operations become difficult because of the non-availability of a staging base despite the availability of local and international relief. if we can maintain those disused airfields to an operable condition then it will give us the freedom to continue with relief operations. relief and rescue operation is one of the prime responsibilities of baf. so baf may take over and maintain some of those airfields at different locations of the country and help in times of disaster. 9.1.2 pesticide control many of the disused airfields were used by the bangladesh department of agriculture extension in the early 70s and 80s. due to the nonavailability of funds, this project was stopped. if bangladesh can manage local or international funds then this can be revived. the disused airfields can be used for this purpose. this will ultimately help bangladesh to improve its agricultural sector. 9.1.3 increase the efficiency of baf most of the time baf traffic needs to hold for a long time for departure and rejoin from the joint airfield. this reduces air time, the aircrew gets less time to practice flying exercises, and sometimes it creates crew fatigue as they hold on the ground for a long time. if baf would have separate airfields then these problems would not be there and that would increase the operational efficiency of the baf as a whole. this will also enhance the efficiency of baf personnel in maintaining an airfield. 9.1.4 promoting flight safety once operating from its airfield, aircrew will be free of tension from excess traffic management, and will not need to hold for departure or rejoin. this will reduce traffic congestion in joint airfields which will ultimately enhance flight safety. 9.1.5 reduce fuel cost of baf baf aircraft hold for a long time before takeoff and also holds during rejoining. thereby a lot of fuel is burnt without any effective output. if baf would have a dedicated runway then this fuel cost would reduce just like the cost of traffic jams in dhaka city. 9.1.6 effective communication if the disused airfields are maintained, then commercial airliners would also provide their service. if baf maintains those airfields then baf may get reimbursement from those agencies. 9.1.7 establishing educational institute baf may establish several schools/colleges/universities in different places in the country around those disused airfields. this will help to promote the social development of the country. these shaheen schools and colleges may become a good breeding ground for future baf recruitment also. 9.2 use of airfields during wartime airfields may be used for the following purposes in wartime: platform to project force. dss vol. 3, 2022, pp.58-66 62 for takeoff and landing most aircraft need a runway. so without a runway, it is almost impossible to project military force during the war. one of the limitations of airpower is a base dependency for refueling, re-arm, and changing the crew. so, without an airfield, it is not possible to conduct any air operation. 9.3 dispersal during war passive air defense, and distributed dispersal is very effective. airfields must be vulnerable from the strategic point of view as it contain high-value targets. from a passive defense point of view to survive for a long time air assets may be kept in reserve in those dispersed airfields. this dispersion may create difficulties for the enemies for detection and destruction. 9.3.1 vital targets under reach roa is increased for friendly aircraft when operating from fabs. this would allow more enemy targets within the reach. these disused airfields may be utilized for this purpose. 9.3.2 reduced interception time if we have forward bases then it will take less time to intercept enemy attackers. 9.3.3 more enemy effort if we have more runways then the enemy will have an increased number of runways to neutralize. it will have more chances to attack the enemy. 9.4 disused airfields and forces goal-2030 baf would have 10 combat squadrons by 2030 as per vision-2030. these ten combat squadrons would include 04 air defence fighter squadrons, 03 multi-role combat aircraft (mrca) squadrons, 02 squadrons of long range ground attack aircraft, and 01 maritime attack squadron [30][31][32][33][34][35]. presently, baf has only 03 squadrons of air defence fighters and 01 ground attack squadron. therefore, baf will add one air defence fighter squadron, three squadrons of mrca, one squadron of ground attack squadron, and one maritime attack squadron. considering the operational priority, baf would add 01 medium-lift transport aircraft squadron with extended range by 2030. one more utility helicopter squadron (medium lift), 01 lands sar, and 01 maritime sar squadron would be added to the present helicopter fleet of baf [27][31]. to enhance aew capability 03 aew aircraft may be added. baf plans to add 03 lrmpa by 2030. 9.5 present operational bases of baf presently baf has four operational (flying) bases (baf bbd, baf bsr, baf zhr, and baf mtr) among which tejgaon runway is not fit for fighter operation. runways of baf bbd, baf zhr, and mtr are jointly operated. flying instructors school (fis) operates only pt-6 from bogra airfield. due to traffic congestion, it would be neither possible nor wise to increase operation from these airfields. as such, baf should look for alternate airfields for her operation. the increased number of flying squadrons as desired by vision 2030 would require additional runways and bases [26][28][29]. the number of operational bases would be increased by another 3-4 for the smooth and safe conduct of air operations. 9.6 future plan of baf (vision 2030) regarding airfield baf has already signed an mou with caab to establish necessary infrastructures and operations from the barisal airfield. moreover, in vision-2030, eight stations (baf shulukia, baf patuakhali, baf tangail, baf bazitpur, baf shamsher nagar, baf lalmonirhat, baf chiringa, and baf comilla) are considered for development. among these shamshernagar and lalmonirhat are already under baf. 9.7 proposed development plan for the airfields options of active airfields for baf use: some airfields are active but not used by baf jets. considering the geographical location, runway length, surface condition, response time in case of interception, operational reach, and ubiquity; baf may plan to develop and operate from the following active airfields: 9.7.1 cox's bazar airfield dss vol. 3, 2022, pp.58-66 63 if we consider runway length (6700'), other infrastructure availability, geo-strategic importance, etc then cox's bazar is the best option for the south-east axis (to encounter myanmar threat) [13][19]. two fighter squadrons and one helicopter squadron may be deployed there. 9.7.2 barishal airfield barisal would give us maximum defense in depth and related advantages. barisal may be used to defend against indian naval air arm attack also. the runway length is also comfortable (6000'). extending the runway by another 2000', baf would be able to operate at least two to three squadrons with a lot of flexibility. baf may have a big plan regarding barisal. 9.7.3 sylhet airfield baf may operate from sylhet (8500') airfield with minimum effort. only the required infrastructure for baf operation is enough and it would enhance the roa of baf aircraft to a great extent. 1 fighter squadron and 1 transport squadron may be positioned there. it will safeguard the north-east axis. 9.7.4 saidpur airfield among lalmonirhat, thakorgaon, and saidpur; saidpur is geographically in the best location. the runway length is 6000', so another 2000' would be enough for any aircraft operation. baf may deploy one fighter squadron and one 1helicopter squadron to cover the north-west axis. 9.8 development of unused airfields: the following disused airfields may be developed. 9.8.1 tangail airfield the runway length is only 1800' and it is difficult to extend much due to its surroundings [6]. i. sar squadron may be placed there to occupy the airfield. this would be good in the future as we have a training area there. ii. patuakhali: runway length is only 1800'. but it would be very good to have a maritime helicopter squadron there. moreover, that area is disaster-prone, so whenever needed it may be used as a forward base. 9.8.2 char sulukia the runway length is only 1800'. one sar squadron may be placed there. this airfield would provide very good support in case of any natural disaster in chittagong. 9.8.3 samachar (kishoregonj) the runway length is 1800'. may be developed as a c&m unit. this airfield would provide very good support in case of an earthquake in dhaka. 9.8.4 miscellaneous baf shamsher nagar, ishurdi, and lalmonirhat may be developed for emergency operations only. the infrastructure available should be maintained with other training units. though the chiringa airfield is almost grabbed by locals, baf may take a drive to capture it if possible, as it would be a good alternative to cox's bazar and chittagong in case of emergency or if any of those airfields become unusable. baf may take over all the airfields so that those are not occupied by the land grabbers.baf may take these airfields and establish schools, colleges, and universities. 10. doctrinal implication airfields played a very vital role in the development of air power. since its inception, airpower has been dependent on airfield support. air-to-air refueling and a multi-fuel tank may have increased the endurance, or vertical takeoff and landing capable aircraft may not require a conventional runway but there is no provision yet which can rearm or change crew up in the air. enemy airpower can be destroyed by a successful attack on its airfield by any means. so the safety and security of the airfield are one of the top priorities of the concerned personnel. dss vol. 3, 2022, pp.58-66 64 more airfields provide the commander freedom of action and maneuver his flying machines. there is no alternative to an airfield to project military power through aircraft. national requirements, location of the airfield, and future force structuring should be kept in mind while developing a disused airfield. 10.1 organizational setup organizational setup includes activities such as job distribution, coordination, and supervision, which are directed toward the achievement of organizational objectives. proper utilization of disused runways certainly needs short-term and long-term organizational setup by baf. 10.2 short-term organizational setup these are the structural reforms to achieve an immediate goal. the following may be required for this purpose:  set up a cell at air headquarters to identify the prospect of disused airfields.  take up the case to appropriate government agencies to hand over those airfields to baf.  top-level government policymakers to be convinced and motivated about the importance of those airfields including benefits for the civil sector.  to establish & approve small-scale to&e for c&m units to look after those airfields..initiate repair works of those airfields by convincing the civil aviation authority of bangladesh (caab) [8] as far as possible. 10.3 long-term organizational set-up these are the structural reforms to achieve a long-term goal. keeping in mind the ‘forces goal -2030’ the following may be done: a.prioritize the airfields that baf wishes to take over. accordingly, establish infrastructures and start flying from those airfields. b. take up the case for an extension of the runway wherever required. local people should be well motivated to cooperate with baf. projects of baf shaheen school/college may help to motivate the local population. c.initiation of new to&e for bases. d.acquisition of combat platforms that would be suitable to operate from those bases. above mentioned setup may look very highly ambitious. as a developing nation, the government has many priority sectors other than armed forces. the economic strength of the country may improve in the future. at that time government might have the capability to support this sector. 10.4 financial implication construction of an airfield is very expensive and sometimes it costs a major amount of the yearly national budget of a developing country. although this paper will not go into details on financial aspects, some endeavor was made to know the approximate cost to make an airfield. as per the chief engineer of caab, it varies on the requirement and type of runway we wish to make. as per rough estimation, it may take 50 core to 5000 core taka to prep a runway of 6000-8000 feet. 11. conclusions air power is very effective as an instrument of war but is always limited by the need for complex, rigid operational and legal bases. more airfields are very good options for a commander to orchestrate his plan and equipment for the successful conduct of war. airfields are the place where there is a runway with all new storage and maintenance facilities from where air power can be projected. so far most of the aircraft need a runway for takeoff and landing and baf is likely to require an airfield in the foreseeable future for its operation. bangladesh inherited a good number of airfields some of which are still in useable condition and others are damaged due to a lack of proper initiative and maintenance. valuable items & accessories from these airfields were taken by interested parties. to augment the defensive capability of bangladesh, these assets need to be protected. if baf could take over and make some of those airfields operational, it would be beneficial in both peacetime and wartime for the country. in war, it would be difficult for men to attack more airfields, and also it would provide good options for us to attack the enemy. civil aviation would also benefit dss vol. 3, 2022, pp.58-66 65 from those airfields. a greater number of airfields would give freedom of relief operation during natural calamity and disaster management. by 2030, baf needs another 4-5 airfields to conduct its operational and training activities. considering the present condition and location cox's bazar, barisal, sylhet, and saidpur may be utilized. patuakhaki, tangail, sarar char, and char sulukia airfields may be used for the operation. more airfields will give baf better training opportunities, reduce fuel costs, and reduce traffic congestion in joint airfields thereby promoting flight safety. it may be used for national requirements by reacting faster when required. declaration of competing interest the authors declare that they haven’t any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] a framework of ai-powered engineering technology to aid altair data intelligence start-up benefits; speeding up data-driven 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(2019). united nations. microsoft word 15-22_224 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.15-22 https://doi.org/10.37868/dss.v4.id224 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 15 concept of the defense material system for the security of indonesian national armed personnel against threats mahyaruddin marpaung1*, sovian aritonang2 1,2 the republic of indonesia defense university, faculty of defense technology, motion power technology, indonesia. *corresponding author e-mail: mahyarudin.mrp@tp.idu.ac.id received: jan. 9, 2023 revised: jan. 29, 2023 accepted: feb. 1, 2023 online: feb. 5, 2023 abstract it is essential to have materials that can support armor systems for the application of body armor composed of anti-ballistic material from coated fibers in trials in order to defend military personnel with better ballistic performance who are lighter against growing threats and conflicts. to support defense-related ballistics. new materials used in personnel protection systems are the subject of this discussion. as ballistic shields, fiber composite materials are currently used due to their light weight and high flexibility. this essay also discusses a thorough analysis of mechanism performance and failure. this study's goal is to advance knowledge about composite material body armor that is covered with a soft spall liner material, which can be used as a model for lightweight, affordable, and safe designs for military troops in times of conflict. © the author 2023. published by arda. keywords: body armor, fiber materials, ballistic protection. 1. introduction one of the ways the development of the defense industry in the area of materials supports the indonesian national armed defense equipment's availability in preserving and maintaining the security of the territory of the unitary state of the republic of indonesia. one of them is the development of bullet-resistant materials, also known as armor, which has been widely carried out through the development of new materials, composition integration, heat treatment, surface coating, and the manufacture of composites made of both metallic and non-metallic materials[1]. in order to increase defense mobility, particularly in the technology of the defense sector, namely in the material section, the government has developed a policy relating to updating and modernizing defense and security equipment (alpahankam), known as the minimum essential force. [2]. the protection of protective armor parts used to protect a person, vehicle, or device from penetration risks that may occur from devices used for explosive or ballistic events is one highly significant material development. protective armor was typically comprised of metal, ceramic sheet, or a combination of these materials. these materials can be made better despite generally offering decent protection. more specifically, it would be great to offer armor that may be lighter than conventional armor [3]. developing armor that can protect against various projectile threats, such as solid particles and molten metals, is desirable, for example, composite fiber material. furthermore, it is better to have defensive armor that is made of materials that are inexpensive and simple to build. similar to soft body armor, stiff plates that shield vital organs from small-arm fire can be added to body armor. body armor has historically had to function against both deformable (bullets) and non-deformable (shrapnel) threats in order to meet international military requirements. usually, each end user develops their own performance requirements. it may incorporate widely accepted (public) standards at times, either with or without the need for extra testing [4]. dss vol. 4, 2023, pp.15-22 16 general performance tests, such as those commonly referred to as the v50 test and the v0 test, may be used to test soft body armor. in order to calculate the velocity (v) at which 50% (v50) or 0% (v0) of the projectile completely penetrates an object, it is necessary to repeatedly strike the target with the threat [5]. the standard polymer fiber materials that are used into the present armor protection systems for military vehicles against threats are the first thing we discuss in this review. the review is then divided into four sections, which each highlights a superior mechanical characteristic of polymer composites created for ballistic purposes. epoxy-based composites have a great potential for application in military vehicle body armor in times of war to shield soldiers from threats as an alternative to aramid materials typically utilized in multi-layered armor systems (mas) [6]. 2. research method this paper is a review article that explains the behavior of the defense material concept in protecting indonesian national armed personnel is examined in this research using a qualitative approach of literature review. based on research findings relating to the subjects and ideas that were acquired from earlier researchers and practitioners, the discussion or analysis is conducted. one method of research is conducting a literature review. comparing literature to other research methods, they each have their unique challenges. doing a study of an issue that has to be solved in relation to the theory to be utilized, the model to be used, or the method to be used calls for a high level of understanding from researchers. finding and determining the literature that is pertinent to the topic is one of the stages in this literature review research. this activity calls for a high concentration on locating data sources, particularly secondary data in the form of journals, articles, and books; the more sources used, the better the results. filter the sources that have been acquired for use in problem-solving by performing literature screening. at this point, the literature review's difficulty level is at its highest since it must be able to fill in any gaps in the current theories using sources, analyze the benefits and drawbacks of each source, and conclude based on the discussion's findings to provide a solution to the problem. 3. results and discussion 3.1 conditions structure protection from threats studying the development of military equipment is essential, especially in protecting soldiers from enemy threats while maintaining a high level of personnel mobility. this is the result of advances in weapons technology, particularly in the field of materials. because the tni must be free to move in the field, the performance of the necessary personal protective equipment must also be good. the indonesian national army needs to be protected from threats, so protection requirements are important. figure 1. concept of threat protection requirements. dss vol. 4, 2023, pp.15-22 17 figure 1 shows the key factors that must be taken into account for protecting military vehicles from threats are ballistic protection, mine protection, noise levels, and the environment. when there is a threat, these components are in the body armor and spall liner to protect military vehicles, especially porcelain. in military operations and peacekeeping, military vehicles are crucial. the type and level of armor protection required for many military vehicles depends on the objective. combat vehicles need to be protected from projectiles, shrapnel, explosive bursts, missiles, and other hazards that could endanger the lives of military personnel [7]. 3.2 body armor made of ballistic panel composite with the growth in threats and conflicts over the past few decades, there has been a lot of interest in the development of personal protection systems with improved ballistic performance and less weight. in this study, many nanomaterials, including carbon nanotubes and graphene with advanced structural and mechanical properties, as well as their strengthening potential of armor composites, are typically used as polymer fibers in the manufacture of body armor [8] examined using a variety of recent studies that are listed in the literature. additionally, natural fibers are incorporated into multi-layered armor systems and ballistic testing that support their importance in the near future. the new materials that are used in specific and important body armor protection systems with the goal of creating the durable and lightweight body armor of the future are the main subject of this brief. table 1. mechanical properties of high-performance polymeric fibers [9] fiber density, (r), (kg/m3 ) modulus (e), (gpa) specific strength (mpa/(g/cm3)) strength (s), (gpa) strain to fracture (e), (%) specific modulus (mpa/(g/cm3)) sonic velocity, vs, (m/s) specific energy absorption capacity (m2 /s2) nylon 6 1140 3 0,44 0,5 18–26 2,63 1622 57,017 s2 glass 2500 86 1,8 4,5 1,8–5,4 34,4 5865 48,600 cotton 1550 6–11 0,19–0,45 0,3–0,7 6–7 3,87–7,10 2663 15,806 silkworm silk (bombyx mori cocoons) 1320 5 0,38 0,5 15 3,79 1946 28,409 spider silk (dragline of nephila) 1320 22 0,98 1,3 40 16,67 4082 196,969 m5 fiber (goal) 1700 450 5,59 9,5 2,0-2,5 264,71 16,269 69,852 m5 fiber (conservation) 1700 300 5 8,5 2,5 176,47 13,284 62,500 zylon hm 1560 270 3,72 5,8 2,5 173,08 13,155 46,474 spectra 1000 970 120 2,65 2,57 3,5 123,71 11,122 46,365 dyneema sk 76 970 116 3,71 3,6 3,8 119,59 10935 70,515 kevlar 29 (1500 denier) 1440 74,4 2,01 2,9 3,38 51,67 7187 34,034 kevlar 49 (1140 denier) 1440 120 2,11 3,04 2,3 83,33 9128 24,277 kevlar 129 (840 denier) 1440 99,1 2,25 3,24 3,25 68,82 8295 36,562 kevlar km 2 (850 denier) 1440 73,7 2,32 3,34 3,8 51,18 7154 44,006 t–1000 (toray) 1820 294 3,88 7,06 2,4 161,54 12,709 46,549 p–120 2190 827 1,02 2,24 0,2 377,63 19,432 1022 swcnt-a 1400 1000 9,29 13 16 714,29 26,726 742,857 swcnt-b 1400 1000 37,86 53 16 714,29 26,726 3,028,571 table 1 displays the relationship between speed and energy absorption capacity in addition to the types of materials punched from the mechanical properties associated with their individual strengths (toughness) [8]. there is a lot of potential for armored applications in the new high-performance fibers based on polypyridobisimidazole that also have very high specific energy absorption capacity and sonic velocity. table 1 illustrates the specific strength of the material plotted against the specific stiffness in figure 2, while the dss vol. 4, 2023, pp.15-22 18 sonic velocity plotted against energy absorption capability (toughness) is shown in figure 2. due to its extremely low specific energy absorption capacity, ultra-high modulus carbon fiber, which has the highest strain wave velocity when compared to other fibers, is frequently employed in ballistic applications. figure 2. specific tensile strength and modulus of high-performance fibers [10]. figure 2 illustrates the relationship between high-performance fibers' specific tensile strength and specific tensile modulus when the latter is determined from bending tests and employed in structural composite applications. 3.3 spall liner for soft body armor armored equipment mounted on the hull of a ground vehicle protects the soldier inside the vehicle to increase survivability. there are additional components that exist inside and outside the ground vehicle but do not add to its structural integrity. the composite used is referred to as a spall liner. the term "spall liner" refers to soft materials that are installed in the crew compartment of vehicles and line the interior surfaces of tanks, combat vehicles, and personnel carriers as a form of interior protection. these materials are typically made of laminated aramid fiber, glass fiber, or high-density polyethylene (hdpe). the purpose of the spall liner is to shield the defensive personnel from being struck by fragments (spall) created during combat. if the armor system is "overmatched," which is the phrase used when the incoming bullet has more penetrating strength than the armor's stopping capability, spall liners can be added as additional security [6]. figure 2 shows examples of a spall liner that helped save individuals who were outclassed. table 2. physical properties of glass fiber, aramid fiber, and ultrahigh-molecular-weight polyethylene (uhmwpe) fiber [7][10] fiber density (g/cm3) young’s modulus (gpa) tensile strength (mpa) uhmwpe fiber 0,97 62-132 2200-3900 aramid 1.44 70-112 1880-2860 s-glass 2.49 89 4750 e-glass 2.55 90 2000 dss vol. 4, 2023, pp.15-22 19 characteristics of the spall liner material, a molecular structure, and high-performance chemical and polymer surfaces that are used to make body armor protection vehicles. table 2 displays one of the materials that doesn't contain chemical components that are susceptible to attack from aggressive agents is uhmwpe, which has a low surface energy and is very resistant to water, humidity, most chemicals, uv radiation, and microorganisms. this allows it to bond with other polymers and adhere to surfaces for coating or more challenging painting. the performance of composite varies with the threat. as a result, uhmwpe is a material that is very effective at reducing the threat posed by deformable bullets. for example, uhmwpe can be as little as half to one third the weight of aramid and glass composites and still perform comparably well in stopping typical deformations that an assault rifle or sniper rifle threatens to do on its own. uhmwpe often uses 20–50% less material for the same performance in terms of fragment protection. it is difficult to predict how different composite materials, such as metal or ceramic, will operate in a system composed of several components [6]. 3.4 vehicle spall liners thermoset resins and thermoplastic resins are two types of polymer matrices that are frequently utilized in the military. phenolic, epoxy, vinyl ester, and polyester are the four most often used thermoset resins in ballistic composites. phenolic resins are frequently selected because they work well with glass and aramid fibers and are fire retardant, liquid and chemical resistant, stiff, and have good ballistic efficiency. because of its excellent toughness, high mechanical and thermal qualities, superior water and thermal resistance, low shrinkage rate, and ease of fabrication, epoxy resin was chosen. vinyl esters combine outstanding mechanical characteristics with simplicity in fabrication [11]. this para-aramid fiber is five times stronger than steel and performs better in ballistic tests than nylon. because they have benefits in several aspects, ultra-high molecular weight polyethylene (uhmwpe) fibers have started to be exploited for ballistic applications recently [12]. figure 2. a spall liner is used on a light armored vehicle [7]. below is a hypothetical armored personnel carrier with a life-saving spall liner in an overmatch. as can be seen, the spall liner significantly reduced the spread of fragmentation while protecting lives. figure 3. armor design [7]. dss vol. 4, 2023, pp.15-22 20 vehicle makers and armored integrators have created a variety of inventive connection techniques that enable soldiers to quickly install these auxiliary systems in the field with extremely basic and limited gear [6]. hardness ratings and impact load resistance are related to resistance to ballistic loads. projectile penetration will be more difficult the harder the material is. however, because of the projectile's high velocity of impact, resistance to shock loads is also necessary, necessitating considerable toughness in the material. a tank is an example of a ground vehicle that needs to have the type of armor used depending on the mission and threat environment. when operating in challenging terrain, special operations must be agile. protection is thus needed from surprise attacks as well as while confronting small arms fire. figure 4. spall liner saves lives in overmatch in hypothetical armor personnel carrier [7]. from the illustration figure 4 shows is crew safety from large-caliber armor-piercing (ap) rounds, landmines, and rocket-propelled grenades. special operations vehicles, for example, cannot be constructed for this level of protection and still be agile. material selection is intended to handle the weight required to give protection from such threats. the weight or area density of the spall liner and the material used in it all affect how far the cone angle can be reduced. as shown in table 2. composite materials with higher performance have a lower cone spall angle while being lighter in weight. utilization of the spall liner has begun to develop into a part of the overall armor system, which will also contain the hull (basic armor), spall liner within the vehicle, and additional armor protection linked to the outside of the vehicle [13]. the objective of additional armor, which is frequently high-hardness steel or ceramic, is to break or bend incoming projectiles, while the metal hull and composite spall coating are designed to catch shards [7]. table 3 displays the stanag 4569 threat level. at the bare minimum range they are anticipated to be encountered, the speeds shown in the table are the anticipated ammunition velocity. in terms of the capacity to penetrate armor, the lower threat levels are the least deadly, and this tendency grows as the threat level rises numerically. occasionally, more than one threat is defined to some extent. for instance, the penetration capabilities of two category 3 threats are comparable. both have 7.62 mm diameter high-penetrating tungsten cores, however, one (b32) is significantly heavier (10.0 g vs. 8.4 g) and has a slightly slower velocity (854 m/s vs. 930 m/s) [5]. testing the area density panels above and below the intended v50 results in the answer for threat level 4 being near to the ideal solution. the answer is then extrapolated using the test findings. the most current data, level 5 testing, were conducted on panels with area densities as high as 200 kg/m2, which did not provide the necessary protection. as a result, extrapolation from the tested panel configurations led to the panel constructions proposed in the table for protection level 5. the suggested protection was extrapolated from the areal densities above and below it at all other levels. dss vol. 4, 2023, pp.15-22 21 table 3. threat solutions and composite protection levels for stanag 4569 [5] threat ammunition v0 (m/s) threat type panel construction v50 (m/s) area density required (kg/m2) 5 25 x 137 mm apds-t, pmb 073 1258 auto cannon, apds ammunition 88 mm pmb 073 composite, 25 mm ceramic surface 1258 276 4 14,5 x 114 mm api/b32 911 heavy machine guns, ap ammunition 16,5 mm, facing ceramic 15 mm 911 90,5 3 7,62 x 54r mm b32 api 854 assault rifles and snipers, ap wc core 25 mm api composite, ceramic facing 854 67,5 2 api bz 695 assault rifle 8 mm composite, 8 mm ceramic facing 917 46,6 1 7,62 x 51 mm nato ball 833 assault rifles/ ball round surfaceless composite panels 833 48,2 1 5,56 x 45 mm m193 937 assault rifles/ ball round surfaceless composite panels 937 38,4 when a threat from high-hardness armor with a bullet-defeating system is present, then add the right coating material. through tests and simulation, it was established that the mechanism of the bullet in armor testing includes (a) asymmetrical forces that cause the projectile to deviate from the incidence trajectory, (b) core fracture, and (c) erosion of the nose of the core. with this technique, good agreement was demonstrated between the simulated and experimental base armor penetration depths and the post-ballistic deformation pattern of perforated plates [14]. based on the threat level given in the table, it is clear that military vehicles' body armor needs to be strengthened in addition to being constructed from materials that must be appropriate for the type of threat and the need to produce materials in line with threats now in existence. 4. conclusions the desire for light, flexible, and robust bodies that can give better ballistic protection is growing as technology, particularly in the area of materials, progresses, especially in light of the increasingly deadly dangers that troops will be subjected to. polymer fibers and composites have been used to create a variety of materials that are stiff, strong, and lightweight. without a doubt, the development of fiber as ballistic protection holds significant promise for assisting and protecting indonesian national armed soldiers in the future. the most recent composite material to be developed for vehicle armor body materials is sandwich structure polymer composite material. along with the significance of soft body armor spall liner composites, which are made of a variety of materials including uhmw pe, aramid, s-glass and e-glass to composite material has good test results and can be employed as an armor body structure material to shield troops from dangers. declaration of competing interest the authors declare that none of the topics discussed in this paper are the subject of any known financial or non-financial competing interests held by the authors. dss vol. 4, 2023, pp.15-22 22 funding information no funding was received from any financial organization to conduct this research. references [1] h. purwanto, r. soenoko, a. purnowidodo, and a. suprapto, "development of ballistic resistant materials as combat vehicle materials in indonesia: review", semin. nas. inov. dan apl. teknol. di ind. 2016, p. a.127-132, 2016. 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[14] n. kiliç, s. bedir, a. erdik, b. ekici, a. taşdemirci, m. güden, "ballistic behavior of high hardness perforated armor plates against 7.62 mm armor piercing projectile", mater. des., vol. 63, pp. 427–438, 2014, doi: 10.1016/j.matdes.2014.06.030. microsoft word 46-51_234 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.46-51 https://doi.org/10.37868/dss.v4.id234 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 46 force development against irregular and hybrid warfare in indonesia jefferson benyamin1*, much mualim2, editha praditya duarte3 1,2,3 republic of indonesia defense university, faculty of defense management, indonesia *corresponding author e-mail: jeffersonbenyamin@gmail.com received: feb. 3, 2023 revised: feb. 23, 2023 accepted: feb. 24, 2023 online: feb. 28, 2023 abstract the development of national defense is directed to be able to answer various possible threats and actual problems that are adjusted to the geographical conditions and dynamics of the strategic environment. current and future threats are growing very fast and increasingly complex. threats to the state can essentially be classified into three types, namely military threats, both armed and unarmed, non-military threats, and hybrid threats. the threats that have emerged during the covid-19 pandemic are irregular warfare and hybrid threats. this research will discuss the analysis of force development to face the threat of irregular warfare and hybrid warfare in indonesia. this research uses a qualitative method with a literature study approach. based on the results of the study, it is concluded that indonesia as a country that has a strategic location and attractiveness of various spectrums needs to always prepare itself by implementing relevant strategies in accordance with the capital already owned in the indonesian nation itself, this is needed to avoid national disunity due to irregular warfare that enters the joints of state life. © the author 2023. published by arda. keywords: development of national defense, irregular warfare, hybrid warfare, indonesia 1. introduction current conditions bring the world no longer in volatility, uncertainty, complexity, ambiguity (vuca) which is characterized by its complexity but in bani which brings disorientation, unpredictability, and chaos. bani as an acronym for brittle, anxious, nonlinear, and incomprehensible was proposed in early 2020 [2]. furthermore, according to cascio, in articulating an increasingly common situation with volatility or complexity, simplicity is not enough to understand the situation that occurs. the existing conditions are not only unstable but also chaotic. the shadow of the future is not only difficult to foresee but completely unpredictable. finally, what is happening is not only ambiguous but also incomprehensible. with the existence of bani, every country in the world, especially indonesia, must pay detailed attention to every threat to sovereignty that will occur. as stated by defense minister prabowo subianto in the leadership meeting, the dynamics of a complex strategic environment have the potential to give rise to various forms of threats such as military, non-military and hybrid threats that will threaten national interests, territorial integrity, danger to state sovereignty and the safety of the entire indonesian nation in the future [7]. current and future threats are growing very fast and increasingly complex. threats to the state can essentially be classified into three types, namely military threats, both armed and unarmed, non-military threats, and hybrid threats. threat estimates in the next five years, in accordance with predictions and priorities, within the framework of existing doctrine, these threats are categorized in the form of real and unreal threats [6]. threats that come must be responded to appropriately. whatever the way and whenever the time. the threats dss vol. 4, 2023, pp.46-51 47 that have emerged during the covid-19 pandemic are irregular warfare [5] and hybrid threats [6]. in this research, the author intends to discuss the development of forces to face irregular warfare and hybrid warfare in indonesia. 2. research method the research method used in this writing is to use a data collection method through a literature study [10]. literature study is a series of activities related to library data collection methods, reading and recording, and processing research materials. the stages that must be taken by the author in library research are as follows:  collecting research materials. the material collected is in the form of information or empirical data sourced from books, journals, the results of official and scientific research reports, and literature on the conditions for the development of irregular warfare and hybrid warfare in indonesia.  reading library materials. in reading research materials, readers must dig deeply into reading materials so as to find new ideas related to the research title.  making research notes. taking notes on research materials is said to be the most important stage because all the materials that have been read must be drawn to a conclusion in the form of a report.  processing research notes. all materials that have been read are then processed or analyzed to obtain a conclusion that is compiled in the form of a research report. data analysis in this study was carried out through the descriptive analysis method, which is defined as an effort to collect and compile data, and then analyze the data so as to produce a comprehensive conclusion. 3. results and discussion 3.1 irregular warfare and hybrid warfare irregular warfare is defined as violent conflict between states and non-state actors with the aim of gaining legitimacy and influence in the surrounding society [3]. geopolitical changes in the world that occurred at the end of the 20th century fundamentally altered the security environment and forced western countries to engage in new types of asymmetric military conflicts with non-state actors, terrorist organizations, and criminal syndicates. new types of threats, various military conflicts and the search for effective responses require reconsideration, generalization and assessment of the latest military experience and the formulation of theoretical concepts that will help to prepare and operate effectively within the zone of military conflict. this condition led to the formulation and formation of new military theories, including hybrid warfare theory. the hybrid war theory developed by hoffman includes four aspects: conventional forces, irregular tactics, terrorism, and criminal acts in one battle space [8]. this is corroborated by the statement of former tni commander marshal hadi tjahjanto that the most prominent threat in the future is a hybrid threat [9]. hybrid threats are threats that mix military and non-military threats. the development of industrial revolution 4.0 provides extraordinary benefits, but at the same time, it also creates a paradox of threats that utilize industrial revolution 4.0 technology so that in the future war will no longer be dominated by military power alone. war has entered the 4th and 5th generation of warfare, namely asymmetric warfare, proxy warfare, and hybrid warfare. hybrid threats can take many forms, such as cyber threats, biological threats, such as the current covid-19 pandemic, and the threat of inequality. the future warfare model will be those who are able to exploit these threats and create security, and sovereignty. 3.2 irregular warfare and hybrid warfare in indonesia the conditions of irregular warfare in indonesia were explained in great detail during the covid-19 pandemic by prof. indrajit, which consisted of four things [5]:  first, the perception that the government has neglected public safety since the first pandemic signals were seen is repeatedly presented to the public through a number of evidences. official remarks by government officials who were not serious in looking at the pandemic storm in the early days of its presence were framed in such a way and presented repeatedly via the mass media. before the pandemic took place, there were many discourses among political elites and the public that led to a number of tensions. the triggers came from a number of sources. first, the thick and lingering feelings of "hurt" over the process and results of the last presidential election democratic party, where the two competing camps still cannot forget the past feud. the losing side still feels strongly that they were cheated by their incumbent opponent. dss vol. 4, 2023, pp.46-51 48  second, there has been a slowdown in growth due to various global trade and economic dynamics due to the fierce competition between the united states and china. the increase in national debt and the increase in imports show the seriousness of the conditions faced by indonesia, which is described as a situation that will be further exacerbated by the pandemic.  third, law enforcement is still considered discriminatory, which is often compared to the phrase "sharp down, blunt up" by some critics. radicals believe that the government uses legal and bureaucratic instruments to "eliminate" its political opponents, especially evident in the pandemic management policy that does not involve "political opponents".  fourth, the political pendulum is moving very dynamically, characterized by the maneuvers of political parties in moving wildly in the face of various rapid environmental changes. the public is confused by this movement so it is not clear which constellation is "friend, which is foe" in the state and democracy. fifth, the submission of a number of draft laws, either government or parliamentary initiatives, which are considered not in favor of the small people. an example is the omnibus law which is considered to only favor businessmen and the power elite, at the expense of ordinary people, or the pancasila ideology bill which has drawn pros and cons everywhere. sixth, there is still a lot of friction between community groups due to various recent issues that are hot to talk about such as the rise of communism, the caliphate, the concept of secularism, primordialism, and so on [1] and forgetting the common interest in facing a pandemic disaster. in addition, the existence of hybrid warfare is a concern for indonesia in running its life. one of the emerging hybrid wars is cyber warfare. the national cyber and crypto agency data states that in 2019 there were 290 million reported cases of cyber attacks in indonesia. compared to the previous year when cybercrime caused us$34.2 billion in losses in indonesia, this number is 25% more. 3.3 analysis of irregular warfare and hybrid warfare in indonesia the occurrence of irregular warfare in the territory of the republic of indonesia, for the following reasons [5]:  by some, the relentless attacks on the government aim to bring down the legitimate government, by trying to convince the public that the government is not working as it should, and is no longer able to manage the pandemic and save the indonesian economy;  the desire to bring down the regime has also begun to appear with various parties trying to compare the success of the current government with previous regimes that are considered far more successful in managing the country, or comparisons with other countries that have succeeded in driving the pandemic out of their territory;  opinion building in the form of psy wars in various ways is put forward to win the hearts of the public, even to convince them, of components that are considered to be respected such as members of the dpr / mpr, retired military, religious leaders, former state officials, and leaders of mass organizations, who criticize the government's way of handling the pandemic; there are a number of movements that interfere with the power in running the wheels of government, as shown through various activities such as demonstrations, motions of no confidence, opposition declarations, debate challenges, complaints to international courts, and others; and  the imposition of will on power has also begun to be seen by many community groups through approaches such as threats of mass mobilization, boycotting the implementation of regulations, ignoring enforced health protocols, and other matters. these reasons continue to surface today by presenting a new war in indonesia called irregular warfare. irregular warfare is a challenge for indonesia coupled with hybrid warfare. both must be anticipated by indonesia on the basis of the sovereignty and integrity of the indonesian state. in the context of irregular warfare, the communication approach is important to be carried out continuously and continuously. failure of political communication can trigger the development of irregular warfare in indonesia. in the context of hybrid warfare, indonesia needs to prepare for it as a response to technological developments. efforts to survive cyber operations are important but no less important is the countermeasure of such behavior so that it does not recur in the future. the presence of a cyber army is also a priority that has been launched, one of which is equipping soldiers with capabilities that they are ready to face possible cyber war [4]. dss vol. 4, 2023, pp.46-51 49 3.4 force development in the face of irregular warfare in facing the challenges of irregular warfare that will occur in the future indonesia needs to optimize all its resources, for this reason indonesia as a large nation already has several resources that can be used as resources to face these challenges including: a. capital geography indonesia's geographical position which is located in a cross position of the world, namely between two continents (asia and australia) and two oceans (indian ocean and pacific ocean) has a very strategic meaning in the development of the indonesian state both in terms of economy, politics, socio-culture and defense and security. with this strategic position, indonesia has become an international trade route both by sea and by air. this makes indonesia a country that has the potential to develop the trade and tourism sectors in order to improve the nation's economy. indonesia is also the largest maritime country. in addition, as stipulated in law number 3 of 2022 concerning national defense, the indonesian national defense system is universal in nature, involving all citizens, territories and other national resources including natural resources and artificial resources that are prepared early by the government and held in a total, integrated, directed and continuous manner to uphold state sovereignty, territorial integrity, and the safety of the entire nation from all threats. to become a strong country, the main prerequisite is the country's ability to organize, prepare and use all resources owned for national interests. therefore, it is necessary to manage national resources for national defense including natural resource management. b. demographic capital indonesia currently has a population of 265 million or 3.49% of the world's total population. indonesia is the fourth most populous country in the world after china (1.4 billion people), india (1.3 billion people) and the united states (328 million people). this is one of the supporting factors in national development as well as in efforts to realize national resilience, but it can also be an inhibiting factor if not managed properly in terms of the quality of its human resources. c. local wisdom and pancasila indonesia's indigenous values have proven to be able to accommodate all group interests into a harmonious blend. these values are local wisdom that can bring indonesia to the peak of glory, including the spirit of gotong royong, helping each other, pluralism, and ethics. the spirit of gotong royong is the local wisdom of the indonesian people that has existed since our ancestors. the precepts in the pancasila state foundation are powerful guidelines that are timeless. the first precept of belief in one god is a guideline in how we practice our religion. the second precept, fair and civilized humanity, is a guideline for interacting with fellow human beings, both domestically and around the world. the third precept, the unity of indonesia, is a guideline for how we state, our strength in the state is unity, not others. the fourth precept, "democracy led by wisdom in the deliberation of representatives" is a guideline in democracy. if we carry out all of this well, we will undoubtedly be able to achieve the fifth principle, social justice for all indonesian people. for this reason, all components of the nation must strengthen themselves and unite their determination to return to the original values and local wisdom of the indonesian people and to guide and implement pancasila correctly and fully in every aspect of the life of the nation and state. in addition, the capital already owned in building defense forces will be related to how much the ability to convert national resources owned into an effective instrument of strength. strategies and ways to deal with future wars include: a. ideology development 1. the practice of the ideological pillars of the indonesian state. objectively and subjectively continues to be developed and improved. 2. pancasila as an open ideology needs to continue to be relevant and actualize its instrumental value so that it is still able to guide and direct life in society. 3. the motto of bhineka tunggal ika and the concept of archipelago insight derived from pancasila must continue to be developed and instilled in a plural society. b. political development in the current era of globalization, freedom of information voiced by the press and media must play an active role as a counterweight to power, not otherwise used by the authorities as a tool to perpetuate dss vol. 4, 2023, pp.46-51 50 power. therefore, national resilience in the political field can be reformulated to create a political institutional system that is more open, transparent, accountable, clean, and non-corrupt, involves broad community participation, and is of a service nature. c. economic development 1. the economic system is directed at realizing fair and equitable prosperity and welfare throughout the archipelago through a people's economy. 2. a populist economy should avoid the following:  liberalism system that only benefits strong economic actors.  the system of ethatism kills the potential and creative power of economic units outside the state system. 3. the economic structure is strengthened in a balanced and mutually beneficial manner in harmony and integration between the agricultural and industrial sectors as well as services. 4. economic development which is a joint effort based on the principle of kinship under the supervision of community members motivates and encourages active community participation. 5. equitable development and utilization of its results are always carried out with due regard to the balance and harmony of development between regions and between sectors. 6. the ability to compete must be fostered in a healthy and dynamic manner to maintain and improve the existence and independence of the national economy. d. socio-cultural development 1. recontextualize, dynamize, and re-present regional culture creatively, realistically and in line with the times. 2. reviving national culture with an integrative and responsive character for the formation of a dynamic and responsive indonesian nation. 3. national integrity as a guide to national resilience in the field of socio-culture. 4. development of religious life in a tolerant, open, and cultured manner. 5. democratic national education to form people of character and culture who are nationalist and responsive to the times. e. defense and security development realizing the condition of the nation's deterrence based on awareness of state defense (patriotism) which contains the ability to maintain the stability of a dynamic state security defense, carry out development and defend state sovereignty by warding off all forms of threats. as illustrated in the indonesian philosophy of war: "the indonesian people love peace, but they love independence more". defense and security must be able to realize preparedness and state defense efforts that contain resilience, ability, and strength to ensure the continuity of national development and the survival of the nation and state based on pancasila and the 1945 constitution. 4. conclusions based on the explanation of force development to face the threat of irregular warfare and hybrid warfare in indonesia above, the author draws several conclusions, namely: 1. irregular warfare and hybrid warfare are defined as threats that must be taken seriously by a country and also have an impact on the sovereignty and integrity of a country. 2. the development of irregular warfare threats continues to emerge as an integral part of the covid-19 pandemic. in addition, hybrid warfare also continues to overshadow indonesia with cyber warfare as one of the factual threats. 3. cases of irregular warfare and hybrid warfare in indonesia must be used as a threat projection with careful strategic preparation starting from shaping to responding and preparing both in terms of budget and human resource readiness. 4. indonesia as a country that has a strategic location and attractiveness of various spectrums needs to always prepare itself by implementing relevant strategies in accordance with the capital that is already owned in the indonesian nation itself, this is needed to avoid the occurrence of national disunity due to irregular warfare that enters the joints of state life. dss vol. 4, 2023, pp.46-51 51 declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] m. affan, "the threat of is proxy warfare on indonesian millennial muslims", indones. j. islam muslim soc., vol. 8, no. 2, p. 199, 2018. [2] j. cascio, "facing the age of chaos", medium, 29-apr-2020. [online]. available: https://medium.com/@cascio/facing-the-age-of-chaos-b00687b1f51d. [accessed: 24-feb-2023]. [3] t. endo, "the conceptual definition of ‘irregular warfare’ and the today’s international security environment", international forum on war history: proceedings, 2017. [4] t. gestoro, "hybrid warfare", in siapkah kita menghadapinya, publika.rmol.id, 2021. [5] r. e. indrajit, p. widodo, r. w. putro, "irregular warfare phenomena in the covid-19 pandemic: situation prediction simulation of post epidemic catastrophe in indonesia", journal of informatics engineering and information systems, vol. 7, no. 3, pp. 522–532, 2020. [6] "ministry of defense strategy to build defense, from diplomacy and overcoming pandemics", nasional. tempo. co, 2021. [7] minister of defense prabowo chaired the second day of the ministry of defense meeting, attended by the tni commander and the indonesian national police chief. 2022. [8] k. kilinskas, "hybrid warfare: an orientating or misleading concept in analysing russia’s military actions in ukraine?", lith. annu. strat. rev., vol. 14, no. 1, pp. 139–158, 2016. [9] a. sudrajat, "panglima tni: hybrid war one of the threats for the next 5 years", news. detik. com. [10] m. zed, library research methods, indonesian torch foundation, 2008. microsoft word 29-35_231 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.29-35 https://doi.org/10.37868/dss.v4.id231 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 29 implementing elements of national security by fulfilling the rights of indigenous people of laman kinipan in central kalimantan (indonesia) khairul umam manik1*, i gede sumertha2, pujo widodo3 1,2,3 faculty of national security, republic of indonesia defense university, indonesia *corresponding author e-mail: khairulmanik26@gmail.com received: jan. 25, 2023 revised: feb. 22, 2023 accepted: feb. 23, 2023 online: feb. 27, 2023 abstract the laman kinipan indigenous people have been in an agrarian conflict with pt sawit mandiri lestari for years; they claim that pt sml has taken their indigenous territory, mainly consisting of customary forest, with a permit issued by the indonesian government. pt sml cleared thousands of hectares of kalimantan forest, which sparked protests from indigenous peoples. the landclearing act affected indigenous peoples in several aspects, such as massive floods that had never happened before, to violent conflicts that befell indigenous peoples. this study aims to find out how the fulfillment of the rights of the laman kinipan, indigenous people, towards the realization of indonesia's national security. this research was conducted using interviews and literature studies with an analysis process using the theory of national security with subtheories of environmental security and human security. the results of this study indicate that the government's failure to fulfill the demands and rights of indigenous peoples affects national security, namely environmental security and human security. the researchers conclude that this conflict is a threat to national security, especially from environmental and human security elements. the government can accelerate the realization of national security if it fulfills the rights and demands of the laman kinipan indigenous people. © the author 2023. published by arda. keywords: national security, environmental security, human security, laman kinipan, pt sawit mandiri lestari, agrarian conflict 1. introduction national security is a function inherent in a country to guarantee security. national security aims to ensure that the state is free from threats that could affect state sovereignty. buzan divides the types of security into five areas: military, economic, social, political, and environmental. in the post-cold war era, national security is no longer focused on protection from military threats but on several other areas [1]. in realizing comprehensive national security, the government must carry out several ideal functions, such as national defense, state security, public security, and human security [2]. when several functions, such as public security and human security, are not fulfilled, that is when conflicts can arise. conflicts have become part of various aspects of life. various elements of life, such as the economy, socioculture, politics, and resources, can trigger conflict. dahrendorf argues that conflicts and clashes will always occur in social life, where people are obedient to changes [3]. one type of conflict that still frequently occurs in indonesia is the agrarian conflict. agrarian conflicts occur for the following reasons: 1. granting of permits/rights/concessions by public officials such as the minister of forestry, minister of dss vol. 4, 2023, pp.29-35 30 energy and mineral resources, head of the national land agency, and regional heads such as governors and regents who classify land/managed areas/natural resources owned by a group of people into concessions of giant business entities in production, extraction, and conservation. 2. violence, manipulation, and deception are committed to acquiring large-scale land for large development projects in production, extraction, or conservation. 3. attempts or actions to expel rural people from the land/area under management/natural resources/which are included in the concession areas of significant business entities. 4. the emergence of resistance from the group [4]. the plantation sector is the sector with the most significant number of agrarian conflicts, with conflicts occurring within it, followed by the forestry, infrastructure, property, mining, military facilities, coastal marine, and agribusiness sectors. the agrarian conflicts claimed victims from the community who fought for their rights in agrarian conflicts. during 2020, the agrarian conflicts that occurred resulted in 169 victims from the community who experienced persecution, criminalization, and even casualties [5]. one of the agrarian conflicts still occurring since 2020 is the agrarian conflict involving the laman kinipan indigenous community. the laman kinipan indigenous community is one of the various indigenous communities registered by the indigenous territory registration agency. the laman kinipan indigenous community is located in kinipan, batang kawa district, lamandau regency, central kalimantan province. sourced to the website of the indigenous territory registration agency (brwa), the laman kinipan, indigenous people have an area of 16,132 hectares of indigenous territory with geographical conditions in the form of hills. the area includes the area of the village of kinipan and indigenous forests. most of the laman kinipan indigenous people have a source of income from gardening [6]. the agrarian conflict involves the private company pt sawit mandiri lestari (sml) which produces palm oil. the background to this conflict was a permit granted by the ministry of environment and forestry to release a forest area of 19,091 hectares through a letter on march 19, 2015. in addition, there is also a decree of the minister of agrarian and spatial planning/head of the national land agency number 82/hgu/kematr/bpn/2017 concerning the granting of cultivation rights in the name of pt sml covering an area of 9,435.2214 hectares which became the legal basis for pt sml to take over several areas, including areas of laman kinipan indigenous community. the permits from the ministry of environment and forestry and the letter for granting business use rights (hgu) for pt sml were deemed legally flawed because they were issued without any discussion and without the consent of the laman kinipan indigenous people who live in the area and as the owner of the indigenous territory [7]. until 2019, based on the mapping of the hgu area by the ministry of agrarian affairs and spatial planning/national land agency, the indigenous area in the form of the laman kinipan indigenous forest had been evicted for the benefit of pt sml's capitalism [7]. it is per law number 5 of 1960 concerning basic agrarian regulations and regulation of the minister of agrarian affairs and spatial planning/national land agency number 10 of 2016, explaining that in the process from the beginning, there were communal rights over indigenous territories until the issuance of communal rights certificates. accordingly, indigenous territories, including indigenous forests, will remain in the name of indigenous peoples. communal rights are certificates from the national land agency given to indigenous peoples who have lived in the indigenous territory for many years and obtain approval from regional heads such as the governor or regent/mayor. based on these legal regulations, it can be stated that land included in these indigenous territories can no longer be classified as state land but as indigenous land controlled by indigenous peoples. so if the government wants to grant usufructuary rights over indigenous community communal land, this must be based on the approval of indigenous peoples [8]. this flawed legal basis created a conflict between the laman kinipan indigenous community and pt sml. the conflict started when there was a disagreement between the lamandau regency government and the laman kinipan indigenous people regarding the boundaries of the area between kinipan village and karang taba village, which border each other. pt sml insists that the land being worked on then was the laman kinipan indigenous people assessed as indigenous territory, and the area of kinipan village entered the karang taba village area [9]. meanwhile, according to the indigenous territory registration agency dss vol. 4, 2023, pp.29-35 31 (brwa), there is already a detailed map of the boundaries of kinipan and other villages, which is made in detail to show the locations of certain trees, certain places in the area of the village of kinipan. the map has also been approved by the villages bordering kinipan, except for batang kawa village, which is also part of the area where pt sml's land clearing plan is planned. then in january 2019, the regent of lamandau determined the border between kinipan village and batang kawa village, which drew protests from the residents of kinipan village because it did not match the map made by them and at the same time, aborted agreements with other villages which had approved the map of the kinipan village border. this conflict escalated into violent conflict when the police arrested efendi buhing, the head of the laman kinipan indigenous community, on charges of stealing a chainsaw used by pt sml. this incident stems from the guard being carried out by the indigenous kinipan youths in the forest area where pt sml employees cleared the land. the failure of the negotiation process between pt sml employees and indigenous youths led to the laman kinipan indigenous youths confiscating the tools used to clear the land. pt sml then reported this to the police, which forced efendi buhing and indigenous youths to be detained, becoming a form of violent conflict. 2. research method this research uses qualitative methods. the use of qualitative methods is one of the choices for researchers because they want to get a comprehensive picture of the implementation of elements of national security through fulfilling the rights of the laman kinipan indigenous people. according to taylor et al. (2016), qualitative research refers in a broad sense to research that produces descriptive data of people's own written or spoken words and observable behavior. the data needed to complete this research was obtained from interviews conducted with various parties, such as the alliance of indigenous peoples of the archipelago (aman), the indigenous territory registration agency (brwa), and the indonesian forum for the environment (walhi). in addition, this research topic is analyzed using several theories, which are described below. 2.1. environmental security environmental security studies according to the united states environmental protection agency (epa), environmental security is a process in which solutions to environmental problems contribute to national security goals [10]. the issue of environmental security has begun to experience an increase in its discussion since world war ii ended and the start of the cold war. when the two big blocks of countries at that time were competing to increase capabilities in the field of technology, the drastic increase in the number of industries could be marked by the increasing intensity of various kinds of pollution from the industrial sector [11]. environmental damage and climate change have been proven to be one of the causes of violent conflict within and between countries. in addition, environmental damage and environmental change issues are among the leading causes of a decline in the level of the economy, which directly or indirectly has a significant impact on the capacity of military forces and resources for a country's defense [12]. in some developed and developing countries, natural resources and environmental services are essential drivers of economic growth and employment levels. income and employment in primary sectors, such as agriculture, forestry, fishing, and mining, and services that depend on the environment, such as tourism, can be negatively affected by environmental changes. as an economy's natural capital base erodes, so does the long-term effectiveness of its military. environmental security is a process in which solutions to environmental problems contribute to national security goals. the issue of environmental security has begun to experience an increase in its discussion since world war ii ended and the start of the cold war. when the two big blocks of countries at that time were competing to increase capabilities in the field of technology, the drastic increase in the number of industries could be marked by the increasing intensity of various kinds of pollution from the industrial sector [11]. environmental damage and climate change have been proven to be one of the causes of violent conflict within and between countries [13]. dss vol. 4, 2023, pp.29-35 32 in addition, environmental damage and environmental change issues are among the leading causes of a decline in the level of the economy, which directly or indirectly has a significant impact on the capacity of military forces and resources for a country's defense [12]. 2.2. human security united nations development program (undp) broadens the conceptualization of security by defining human security as security from chronic threats such as hunger, disease, and oppression and protection from sudden and painful disturbances in the pattern of daily life [14]. according to undp, some of the components of human security are individual-centered components, such as economic security, food security, health security, environmental security, personal security, community security, and political security [14]. one of the efforts by the un in human security was establishing the human security commission in 2001. in responding to this issue, the human security strategy was made proactive by emphasizing conflict prevention and peacebuilding rather than in the form of humanitarian response assistance [15]. in achieving human security goals, the human security commission proposes two main strategies: protection of empowerment. protection strategies refer to the norms, processes, and institutions that protect people from critical and widespread threats [16]. this strategy is top-down in its implementation, where the state must show its responsibility to form a protective human security structure [15]. the implementation of national security, which is comprehensive and includes a combination of territorial security (defense) and human security, must involve all elements of society by cooperating with all state institutions. this comprehensive nature of national security raises the implication that one or only a few institutions cannot handle the concept of national security because it has become a standard security, so there must be a form of cooperative security between all components, both military and civilian [17]. 3. results and discussion 3.1 environmental security and laman kinipan agrarian conflict environmental security is one of the elements of national security because of the importance of environmental issues in the current era as the earth ages and human innovation progresses at the expense of many aspects of the environment, such as deforestation, the disposal of carbon gas emissions by companies and government elements, motorized vehicles, burning fossil fuels for electricity generation, and others. deforestation has a significant influence on the issue of national security. deforestation has several significant effects, such as global warming, which results in rising sea levels, the loss of millions of species of flora and fauna in forest areas, and various threats of major disasters, and becomes a threat to national security if it continues to be maintained [18]. in addition, according to the ministry of defense of the republic of indonesia (2015), the indirect impact of climate change on national security is that basic human needs will be disrupted and cause disruptive impacts on national security. it will be difficult for humans to readjust themselves to manage stress. it will eliminate political stability, a weakened economy, a crisis of basic human needs such as water, food, and various diseases to both vertical and horizontal conflicts. in addition, the impact of climate change due to deforestation on the laman kinipan indigenous forest has caused a major flood disaster that had never happened before. natural disasters ultimately affect national security [19]. today, the impact of climate change is starting to be felt, such as increasing temperatures due to global warming and rising sea levels due to melting ice at the poles, which will threaten national security for countries which makes the issue of environmental security one of the vital security issues to be discussed. long-term deforestation to clear land has been scientifically proven to exacerbate environmental damage. some of the impacts of deforestation on environmental damage are a decrease in the quality of the atmosphere layer, contributing to an increase in greenhouse gasses which leads to an increase in global temperatures [20]. bruhl and simonis revealed that three things accelerate environmental degradation/damage, namely: 1. the attitude of humans who over-exploit resources, both non-renewable resources and renewable resources. 2. the burden on the earth exceeds its limits and carrying capacity. 3. human activity often destroys ecosystems [21] dss vol. 4, 2023, pp.29-35 33 in the laman kinipan indigenous area itself, environmental issues are important because the indigenous forest area has many functions, namely as a producer of oxygen, as ecological wealth in it, as a place for indigenous peoples to find a source of livelihood, and so on [22]. in addition, the geographical location of the village of kinipan, which is downstream of the batang kawa river watershed, makes kinipan the last place of defense for the batang kawa watershed. suppose deforestation in the kinipan affects the watershed area in the kinipan. in that case, the upstream part of the river and along the batang kawa watershed will be damaged, affecting the villages around the batang kawa watershed [23]. in another source, the impact of the deforestation of the laman kinipan indigenous forest, which was replaced by an oil palm plantation owned by pt sml itself, had an ecological impact in the form of the presence of an unprecedented big flood disaster in the village of kinipan due to the loss of forest areas that function as rainwater catchment areas [24]. environmental degradation is a threat to national security in indonesia. the laman kinipan agrarian conflict is based on the fact that pt sml carried out deforestation of indigenous forest areas, which have been well guarded and managed by the laman kinipan indigenous people. massive deforestation of forest areas to be planted with oil palm and lasting for decades will threaten environmental security. another impact of deforestation that the residents of kinipan directly felt was a natural disaster in the form of a massive flood that inundated the area around the batang kawa river, including the residential area of the laman kinipan indigenous people. this unprecedented big flood is the impact of deforestation, which has been functioning as a rainwater catchment area. when the soil cannot absorb water, the nearest destination for water is the batang kawa river which causes the river to overflow. natural disasters threaten national security because they can disrupt the stability of various fields, such as the economy, society, and politics, and cause damage to public facilities and infrastructure. environmental security ultimately significantly influences national security because if environmental security is threatened, many negative impacts will be generated and felt by various parties. 3.2 human security and laman kinipan agrarian conflict in terms of elements of human security/human security/social security, the conflict that occurs is a threat to human security. the agrarian conflict of the laman kinipan indigenous community, in addition to causing violent conflict between indigenous peoples and the indonesian national police who received pt sml's complaint in 2020, also caused horizontal conflict between indigenous peoples who had different opinions about the takeover of pt sml's indigenous forest [23]. in the white paper by the ministry of defense of the republic of indonesia (2015), conflicts are part of a social disaster threatening national security that the government of indonesia must anticipate. the state must guarantee human security because security is an essential element of national security. threats to human security ultimately lead to national security itself. one of the theories of human security established by the united nations development program is security from fear. the human security approach to protecting individuals from violent conflict while recognizing that the threat of violence is closely related to poverty, lack of state capacity, and other forms of injustice. this approach argues that a limited focus on violence is a realistic and manageable approach to human security. this approach's main concerns are emergency relief, conflict prevention and resolution, and peacebuilding [25]. the laman kinipan agrarian conflict affected the human security of the laman kinipan indigenous people. related to the impact of environmental security, natural disasters in the form of floods threaten the human security of indigenous peoples because they cause health problems, potential casualties, loss or damage to their homes, and difficulties in earning income. human security is threatened due to the destruction of nature and the environment for the benefit of a few people who expect material gain. apart from that, this conflict also threatens the human security of the laman kinipan indigenous people, as evidenced by the excessive detention of the head of the laman kinipan indigenous community effendi buhing by law enforcement officers. effendi buhing, who was detained by coercion which led to violent conflict, violated a person's human rights. in addition, the impact of this conflict on threats to human security is acts of violence, intimidation, land clearing, and the arrest of members of the indigenous community who are not proven to have committed a crime [26]. we can see that this is a form of violation of a person's right to maintain human security. if this conflict becomes a protracted conflict, then the potential for conflict escalation and the scope of the conflict can dss vol. 4, 2023, pp.29-35 34 become more significant and threaten the stability of national security because one form of threat to national security is a social disaster which includes conflict. 4. conclusions the goal of the state to guarantee national security must be realized not only from one or several elements of security but also from all elements of national security. national security will be threatened if one or several elements of national security are threatened. in this study, the case of agrarian conflict involving the laman kinipan indigenous community and pt sawit mandiri lestari can pose a threat to national security if it is studied using the theory of national security with two examples of elements of national security, namely environmental security and human security. this conflict has become a threat to environmental security because of the environmental destruction carried out by pt sawit mandiri lestari through a large-scale deforestation program in kalimantan forests which also seized the laman kinipan customary forest area. deforestation has been proven as one of the causes of threatening environmental degradation. forest management by the laman kinipan indigenous community which is carried out sustainably and does not damage the environment will ensure environmental safety from major forms of deforestation for the benefit of capitalism. conflicts that have reached violent conflicts have demonstrated threats to human security. conflict as a form of social disaster becomes an obstacle to the realization of national security. in addition, environmental security threats are related to social security due to natural disasters that have occurred and have had an impact on the basic rights of the kinipan people who are victims of flood disasters, such as health problems, building damage, and food shortages. the form of criminalization against the residents of kinipan who fight for their rights is a form of threat to social security and a violation of human rights. by resolving conflicts and fulfilling the rights and demands of the laman kinipan indigenous community, two elements of national security, namely environmental security, will be realized and can accelerate the realization of national security. acknowledgments gratitude is addressed to major general tni (ret.) dr. i gede sumertha ky, psc, m.sc and major general tni dr. ir. pujo widodo, s.e., s.h., s.t., m.a., m.si., m.d.s., m.si. (han) as the research supervisor during the study time of the corresponding author at the peace and conflict resolution studies, faculty of national security, republic of indonesia defense university. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] b. buzan, people, state, and fear: an agenda for international security studies in the post cold era, 2nd edition, london: harvester whatseaf, 1991. [2] j. sudarsono, lemhannas seminar in cikeas bogor, interview, 2007. [3] g. ritzer, d. j. goodman, modern sociological theory, jakarta: kencana, 2010. [4] n. f. rachman, "the explanatory chain of chronic agrarian conflicts", bhumi jurnal agraria dan pertanahan, no. 37, pp. 1-14, 2013. [5] agrarian reform consortium, "notes on the end of year 2020", 2020. [6] indigenous territory registration agency, "laman kinipan indigenous territory", [online]. available: https://www.brwa.or.id/wa/view/vdlinvdlwxixd2m. [7] indonesian forum for the environment, "stop the confiscation of indigenous territories and dss vol. 4, 2023, pp.29-35 35 criminalization of indigenous peoples of laman kinipan!", 27 august 2020. [online]. available: https://www.walhi.or.id/hentikan-perampasan-wilayah-adat-dan-kriminalisasi-masyarakat-adat-lamankinipan. [8] n. k. krismanika, i. p. g. seputra, l. p. suryani, "the granting of cultivation rights on communal land according to land law in indonesia", jurnal interpretasi hukum, vol. 1, no. 1, pp. 161-166, 2020. [9] b. baskoro, "sml denies allegations of land acquisition, here's the response of the kinipan traditional elders," 11 novmber 2018. [online]. available: https://www.mongabay.co.id/2018/11/11/sml-bantah-tudingan-caplok-lahan-begini-jawaban-tetua-adatkinipan/. 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[15] c. c. muguruza, "human security as the link between humanitarian action and peacebuilding", in the humanitarian challenge, springer, 2015, pp. 41-46. [16] united nations, "human security now: protecting and empowering people / commission on human security", 2003. [online]. available: https://digitallibrary.un.org/record/503749?ln=en. [17] e. fitrah, "the idea of human security and indonesian national security policy", jurnal insignia, vol. 2, no. 1, pp. 27-41, april 2015. [18] g. singh, b. singh, "deforestation and its impact on environment", international journal of advance research in science and engineering, vol. 06, no. 03, pp. 262-268, 2017. [19] republic of indonesia ministry of defense, "republic indonesian defense white paper", 2015. [online]. [20] b. d. siswoko, "development, deforestation and climate change," jurnal manajemen hutan tropika, vol. xiv, no. 2, pp. 88-96, 2008. [21] t. brühl, u. e. simonis, "world ecology and global environmental governance", discussion papers, research professorship environmental policy, 2001. [22] b. herinata, interviewee, eecutive director of walhi central kalimantan. [interview]. 28 april 2022. [23] f. kurnianto, head of aman central kalimantan, interview, 21 june 2022. [24] save our borneo, "accepting the ecological impact, kinipan experienced a major flood", 9 july 2020. [online]. available: https://saveourborneo.org/terima-dampak-ekologi-kinipan-banjir-besar/. [25] united nations development programme, "human development report 1994", undp, 1994. [26] cnn indonesia, "the head of the kinipan indigenous community was released after being arrested by the police", 27 august 2020. [online]. available: https://www.cnnindonesia.com/nasional/2020082717405012-540047/ketua-adat-kinipan-dilepas-usai-ditangkap-polisi. microsoft word 16-25_72.docx defense and security studies issn 2744-1741 vol. 1, no. 1, december 2020, pp.16-25 original research https://doi.org/10.37868/dss.v1i1.72 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/ ) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 16 an overview of gurney method for estimating the initial velocities of fragments for high explosive munition alan catovic1* 1 defense technology department, mechanical engineering faculty, university of sarajevo, bosnia and herzegovina *catovic@mef.unsa.ba © the author 2020. published by arda. abstract the literature survey, related to the initial velocity of fragments for he ammunition is presented. the basic gurney model for fragment initial velocity, that can be used for different munition configuration, is presented. the research we performed using the gurney method for a different projectile types is given. keywords: fragment velocity; gurney constant; warhead detonation; 1. introduction in the analysis of high explosive (he) warheads with fragmentation, it is necessary to determine the initial velocity of the fragments, which is very important parameter of the terminal ballistics. theoretical and experimental research has shown that the initial velocity of fragments formed by fragmentation of he warheads depends on the ratio of explosive charge mass c and mass of warhead body m metal, as well as mechanical characteristics of warhead body material, type of explosive charge, and its detonation parameters. fig. 1 shows a schematic representation of the he warhead detonation process (controlled fragmentation). the mechanism of fragmentation is complex. the process of projectile expansion begins with the initiation of the primary explosive charge and proceeds with the detonation of the main charge, whereby the energy of the explosive is transformed very quickly from a potential form into mechanical work. explosions caused by rapid chemical reactions in the matter are characterized by the release of heat and the formation of large amounts of gaseous products expanding at high speed. the formation rate of gaseous products during detonation is so high that the chemical reactions inside the explosives are completed before the detonation products can significantly expand into the environment. the temperature of the detonation products is several thousand degrees celsius, and the pressure of the detonation products at the time of completion of chemical reactions is very high (several hundred thousand bars). due to such a state of gas, a process of the sudden expansion of the detonation products occurs, which causes the projectile body to expand and to fragment. figure 1. schematic representation of the he warhead detonation process [12] dss vol. 1, no. 1, december 2020, pp.16-25 17 data on the initial velocity of the fragments are needed to be able to estimate the elements of the trajectory of the fragments, and thus their kinetic energy at a given moment (during movement through the atmosphere). the measure of the explosive power is mainly expressed in the literature using the strength of the shock wave generated by that explosive, or on the total chemical energy that the explosive contains. in this way, the velocity of the shock wave, the detonation pressure, and the heat generated by the detonation of explosives can be expressed. although this way of understanding and assuming the properties of explosives is accurate, it does not provide information on the initial velocity that an explosive can communicate during detonation of munition to fragments [1]. during world war ii, physicist ronald w. gurney published several scientific papers explaining how the initial velocity of fragments could be calculated with relatively high accuracy. his scientific works thus created a method that is still used today to calculate the initial velocity of fragments. this method was developed to suit different systems and configurations of metal-explosive systems. although the shock wave plays a very large role in the transfer of energy from explosives during detonation to metal, gurney in his method does not take into account the properties of the shock wave itself. in his research, gurney assumed [1] that during detonation, a final amount of energy is released by the explosives, which is converted into kinetic energy of fragments and kinetic energy of detonation gases. he also assumed that detonation gases have a uniform density and a linear one-dimensional velocity profile. the gurney method can be used for all one-dimensional metal-explosive systems. the gurney constant, which appears in his method, can be estimated experimentally (explosive cylinder expansion test), computer programs (in hydrocodes), and analytical models. henry (1967), jones (1980) and kennedy (1970) reported gurney’s constant values for certain explosives while dobratz (1982) made the greatest contribution [2]. some researchers (kennedy, randers-pehrson, lloyd, odinstov) have proposed certain modifications of the gurney model, and other authors (hirsch, chanteret, chou-flis, kleinhanss, hennequin) have applied the gurney method to imploding configurations (configurations where the explosive is on the outside and the body on the inside; i.e. liner and explosive in heat warheads). modifications of the gurney base model mainly consisted of deriving formulas for geometric configurations of systems not covered by the original gurney model, and for a larger range of m/c ratios. henry (1967), jones (1980), and kennedy (1970) also used gurney’s method for different metal-explosive configurations. hirsch (1986) modified the basic gurney formulas for exploding cylinders and spheres to extend their use to lower metal to explosive mass ratios m/c [2]. another extension of the gurney method was given by chanteret (1983) who developed an analytical model for symmetric geometric configurations. fucke et all. (1986) and bol and honcia (1977) measured fragment velocities for large m/c ratios [2]. karpp and predeborn (1974, 1975) showed that the assumptions about the initial velocity of the fragments obtained by the gurney method are adequate for cases when the flow is one-dimensional and for practical c/m relations that can be encountered in reality (0,1 <c / m <2) [2]. aziz et al. performed an analysis for an open sandwich configuration, where the metal was considered a solid, and where the gases were approximated by the ideal gas equation [1]. butz et al. (1982) analyzed gurney’s model for symmetric sandwich configuration. they found that the gurney model fully follows the results obtained experimentally, and even for very small m/c ratios. the smallest ratio they considered was 0,05, and even for such a small ratio, the gurney model gave a result that agrees with the experimental result [1]. cooper states that the gurney constant can be estimated using the detonation velocity of explosives [3]. different authors [4-11] investigated the influence of rarefaction waves from two ends in cylindrical warheads, since the length of casing is not infinite, and consequently, fragment velocities are lower than the gurney velocity prediction. gao [4] concluded that the fragment velocities in the central part of the warhead are not influenced by rarefaction waves when the l/d ratio (slenderness) was more than 2. huang et al. [11] proposed modified formula for the fragment velocity from the cylindrical casing, initiated at one end. charron [10] also analysed rarefaction waves influence on fragment velocity. in recent times, numerical simulations in terminal ballistics are increasingly used. they are based on the formulas of continuum mechanics, using conservation equations, together with constitutive equations that define the behavior of the material, and specifying the initial and boundary conditions related to a given problem. dss vol. 1, no. 1, december 2020, pp.16-25 18 2. gurney method the gurney equation describes the initial velocity of the fragments as a function of the ratio of the mass of the explosive charge to the mass of the metal body and the empirically determined constant (gurney constant). in deriving the gurney formula, a hollow cylinder of mass m, of inner radius r, filled with an explosive of mass c and density  is considered. the initial velocity of the fragments for the cylindrical configuration of the metal body and explosive can be written in the form:         2 1 2 c m e vm (1) where the parameter e2 represents the gurney constant (the name characteristic gurney velocity can also be found in the literature) and depends on the m/c ratio. the quantity e (so-called gurney energy) has the dimension of energy per unit mass (j/kg), so the parameter e2 has the dimension of velocity (because the unit for energy is j = kgm2/s2). the generalized gurney formula (for different body warhead shapes) can be written in the form: 1 0 2 2            g g n n c m ev (2) where the constant ng can have value of 1, 2 or 3, depending on whether the body is a flat, cylindrical or spherical configuration. a schematic representation of possible configurations is given in fig. 2. a detailed derivation of these formulas can be found in references [2,14]. fig. 2 expressions for initial velocities of fragments in different geometric configurations [2] the expression for the initial velocity of fragments in flat symmetrical sandwich configurations (expression 2 at ng = 1) can be used to calculate the parameters of explosive-reactive armor on tanks. expression 2 at ng = 3 is applied to hand grenades and some types of cluster projectiles, while expression 2 at ng = 2 is reduced to expression (1) and is used to estimate the initial velocity of fragments in most he warheads. theoretically, the maximum initial velocity of the fragment is obtained when the mass of the body m approaches zero, and for cylindrical configurations it is ev 22max0  . the gurney constant can be estimated using tests, computer programs (using i.e. jwl equations of state for explosives), and analytical models (i.e. kamlet and finger use thermochemical parameters of explosive charge to estimate the gurney constant; kennedy gives the expression e  0,7ed, where ed is the detonation heat of the explosive). cooper states that the gurney constant can be estimated via the detonation velocity of explosives d (which, depending on the density and composition of the explosives, can be determined in computer programs, i.e. explo5), by the expression: 97,2/2 de  (3) the value of 2.97 from expression (3) was obtained by averaging the values of e2 for known explosives (table 1). this relationship is capable of accurately predicting e2 of sensitive and moderately sensitive near ideal explosives; however, this equation is somewhat unsuitable for predicting e2 of insensitive and nonideal explosives (ie. nto, pbx-9502, afx-902), because it overestimates e2 of insensitive explosives [20]. dss vol. 1, no. 1, december 2020, pp.16-25 19 table 1 shows the values of density, detonation velocity and gurney constant for different types of explosive charges. similar data for different types of explosives can be found in the nato manual aastp-1 [13]. table 1. experimental values of density, detonation velocity and characteristic gurney velocities for different types of explosives [3] explosive density (kg/m3) det. velocity (m/s) gurney constant (m/s) ed 2/ composition a-3 1590 8140 2630 3,09 composition b 1710 7890 2700 2,92 composition c-3 1600 7630 2680 2,85 cyclotol (75/25) 1754 8250 2790 2,96 h-6 1760 7900 2580 3,06 octogen 1835 8830 2800 3,15 lx-14 1890 9110 2970 3,07 octol (75/25) 1810 8480 2800 3,03 pbx 9494 1840 8800 2900 3,03 pbx 9502 1885 7670 2377 3,23 petn 1760 8260 2930 2,82 rdx 1770 8700 2830 2,97 tetril 1620 7570 2500 3,03 tnt 1630 6860 2370 2,89 tritonal (80/20) 1720 6700 2320 2,89 in real conditions, the initial velocity of the fragment represents the resultant of the initial velocity of the fragments (gurney expression), the translational velocity of the projectile at the moment of impact on the target and the rotational velocity of the warhead (if the warhead rotates during the flight; gyroscopic stabilization). but since the translational and rotational velocity components are much smaller, only the initial velocity value, determined by the gurney method, is usually used in the calculations. using gurney's methodology to estimate the initial velocity of the fragments ome does not make large errors in determining the total initial velocity of the fragments. by considering the values of the projectile's impact velocities (which are generally different for each angle of incidence), the calculation can be potentially closer to the real situation, with the spray of fragments moving in the direction of the projectile's movement. in an axisymmetric system with variable diameter, the c/m parameter is calculated depending on the axial position. this means that the initial velocity of the fragments will also vary, depending on the position on the projectile body. the initial velocities of the fragments, calculated by gurney's formula, agree well with the test data for he projectiles, as shown in fig. 3 (left). fig. 3 (right) shows a comparison of the initial velocities, calculated by the gurney method, with the experimental data for a steel cylinder with ratio l/d = 2 (ratio of length and diameter; warhead slenderness), filled with composition b and initiated from the left side. fig. 3 illustrates how effects in the end part of the cylinder can affect the prediction of the initial velocities. figure 3. comparison of the gurney method with experimental data [2] dss vol. 1, no. 1, december 2020, pp.16-25 20 the standard cylinder test, developed at lawrence livermore national laboratory (llnl), is used in the research of the phenomenology of the expansion of metal cylinders due to the action of explosive charges. several types of explosives can be used, as well as several types of cylinder materials (i.e. copper and two types of steel with different percentages of carbon and alloying elements). karpp and predebon observed that in most of these experiments the maximum initial velocity of the fragments was achieved at the expansion ratio of the body r/r0 = 2 (the diameter of the body in the process was expanded twice compared to the initial one). even at the ratio r/r0 = 1,75 about 92% of the maximum initial velocity of the fragments has already been achieved. nevertheless, it seemed necessary to consider the effects of gas leakage through the end parts of the cylinders, and to include the obtained models in non-stationary numerical simulations, to obtain more accurate values of initial velocities. in this sense, karp and predebon used the hemp program, based on the finite element method, to model the process of natural fragmentation. the standard jwl equation of state for explosives was used, the cylinder was modeled as an elasto-plastic material, and the effects of gas leakage were taken into account. a comparison was made with the experimental data, for cylinders with different types of steel and with geometric ratios l/d = 2. the explosive charges were tnt, composition b and octol. the agreement between the experiments and the calculation in the program was great [15]. when estimating fragment initial velocity for he projectiles, the gurney model and cad techniques for modeling can be used (fig. 4). i.e. 3d models of projectiles can be divided into quasi-cylindrical segments, with characteristic front, center and rear part. for each segment of the projectile body, the initial velocity of the fragments is determined separately, using expression (1), and thus the profile of the initial velocities of the fragments along the projectile body can be obtained. it is usually assumed there is no expansion of the projectile body before fragmentation and that the initial velocity vector of the fragments is normal to the projectile body on each segment. crull and swisdak [17] follow a similar procedure in their research. figure 4. a 3d model of a he projectile, divided into segments [16] numerical simulations are used often during the past 20 years, especially with the introduction of cheap and powerful processor clusters. these simulations are based on the conservation equations, with the use of equations of state, material strength, and fracture models. figure 5 shows the results of a numerical simulation of the detonation of a 155mm he m107 projectile, performed by prytz et al. [18] in the autodyn, where the analysis of the initial velocities of the fragments was performed and compared with the values obtained in the split-x program. the results show a relatively good agreement of the values of the initial velocities of the fragments, and potential for using the simulations for calculation of fragment initial velocities. figure 5. initial velocities fragments for 155mm m107 (split-x and autodyn) [18] dss vol. 1, no. 1, december 2020, pp.16-25 21 3. application of gurney method to he projectiles in our research (zecevic et al. [19]), we analyzed the influence of explosive type and projectile design on the values of the initial velocities of fragments for different types of he projectiles (artillery and mortar projectiles, as well as rocket projectiles warheads). figures 6 and 7 show the influence of explosives type (tnt and composition b) on the initial velocity of fragments for several types of he projectiles (152 mm m84 artillery projectile, 128 mm m87 missile warhead and 120 mm mortar projectiles, models w1 and w2). the abscissa on the diagrams represents the relative distance of individual projectile segments from the top of the projectile. the diagrams show that the use of explosives with better detonation characteristics (higher density, higher detonation velocity and higher detonation pressure of composition b compared to tnt charge) can significantly increase the initial velocity of the fragments. figure 6. variation of initial velocity of fragments, depending on the type of explosives (tnt and composition b) for mortar he projectiles 120mm (warheads w1 and w2) [19] figure 7. variation of initial velocity of fragments, depending on the type of explosives (tnt and composition b charge) for rocket projectile warhead model 128mm he m87 and artillery projectile model 152mm he m84 [19] figure 8 shows the influence of projectile design on the values of the initial velocity of fragments for several types of he projectiles (artillery projectiles 105mm, 122mm, 152mm and 155mm, rocket projectile warheads 128mm and mortar projectiles 120mm). the diagrams in fig. 8 show that by changing only the design of the projectile (i.e. increasing the ratio of the mass of the explosive to the mass of the projectile body c/m, reducing the thickness of a body) can also significantly increase the initial velocity of the fragments on individual segments of the projectile. the maximum initial velocities of the fragments are achieved in the central parts of the he projectile, where the largest mass ratios c/m are present. fig. 8 also shows the simultaneous influence of both the type of explosive and the design of the projectile on the initial velocity of the fragments for 122mm caliber artillery projectile. thus, the 122mm he m76 projectile, which has a higher c/m ratio and explosive (composition b) with better detonation characteristics than in the case of 122mm of-462 (tnt) projectile, has a higher initial velocity of fragments on all projectile segments. the higher initial velocity generally corresponds to the higher kinetic energies of the fragments leading to a larger lethal zone of the projectile. dss vol. 1, no. 1, december 2020, pp.16-25 22 if we look closely at initial velocities values of fragments for projectile 122mm he of-462 (maximum value of around 1200 m/s) in fig. 8, the front part of the 122mm of-462 projectile has somewhat higher initial velocities. on the other hand, the rear spray of fragments has a lower initial velocity, because of the smaller c/m ratio. figure 8. influence of projectile design on the values of the initial velocity of fragments for several types of he projectiles [19] catovic [20] provided a different way of displaying the initial velocities of fragments (comparing i.e. to fig. 8), presented via a polar diagram (grapher software can be used) in which one axis represents the initial velocities of the fragment (units m/s) and the angular axis of the diagram represents the angles measured from the projectile axis to the centers of the individual projectile segments. the point of origin (lower part of fig. 9) is represented by the projectile center of mass. the directions in the lower part of fig. 9 (on the projectile) should not be confused with the initial velocity vectors; they serve here only to estimate the angles measured from the projectile axes to the centers of the individual projectile segments (in order to construct the diagram in fig. 10). such diagrams can be useful in visualization of the parameters for he projectile terminal ballistics. we used polar diagrams also in our model for determination of he projectile lethal zones [21]. in our research [20] we used the gurney model also as an integral part of a new method for determination of lethal radius for high-explosive artillery projectiles (fig. 10). in this model, the values of the initial velocity of fragments are required in order to accurately calculate fragment trajectory through the atmosphere on its way to the target. this method showed promising results confirming the applicability of the gurney model. dss vol. 1, no. 1, december 2020, pp.16-25 23 figure 9. variation of initial fragment velocity for 122mm he of-462 projectile as a function of segment position, presented using the polar diagram [adapted from 20] figure 10. body segments of artillery projectiles, for which gurney method is applied, used in our model for determination of the lethal radius [20] dss vol. 1, no. 1, december 2020, pp.16-25 24 4. limitations of gurney model the scope of application of gurney equations is limited due to certain assumptions taken when deriving them. henry (1967), jones (1980) et al. and kennedy (1970) made a list of these limitations, and they are cited by walters and zukas [2]: range of m/c ratio. henry (1967) claims that gurney's equations give good results for the range 0,1 < m/c < 5, while kennedy (1970) claims that the range of application of gurney's equations is 0,2 < m/c < 10. acceleration phase. the gurney method in its basic form is not able to analyze motion during acceleration. therefore, henry (1967) and jones (1980) et al. took advantage of the assumption of a linear velocity profile in uniformly dense gas and combined it with the gas state equation to obtain acceleration when moving a metal plate, and came to two conclusions. the first conclusion is that detonation gases must be fully allowed to expand to atmospheric pressure, and the second is that the fragment will reach the calculated velocity only if no external force acts on it in the acceleration phase. assumption of the gas velocity profile. assumptions of the linear velocity profile and constant density of the expanding gas are essential assumptions. gurney's method in its basic form neglects the effect of maximum pressure. on the other hand, although these assumptions give certain errors, they greatly facilitate and shorten the derivation of gurney formulas. resistance to deformation. the forces in the metal that oppose the deformations are not taken into account, except for inertia. these forces reduce the assumed initial velocity of the fragment. metal fragmentation. metal disintegration is possible when the m/c ratio is < 2 for high-density explosives. the explosion can in some cases be prevented if a cavity of a few millimeters is made between the explosive and the metal. early cracks on the projectile body. leakage of detonation gases through cracks in the body can significantly reduce the assumed initial velocity of the fragment, depending on the geometry of the crack and the amount of gas released. 5. conclusions the literature related to the initial velocity of fragments for he ammunition is presented. the basic formulas for fragment initial velocity, that can be used for different configurations of munition, are presented. in the last part, the research we performed using the gurney method for different types of projectiles is given. the gurney model for fragment initial velocity, which can be used for various ammunition setups, is described. the research we conducted using the gurney method for various types of projectiles is given. the results show that the use of explosives with better detonation characteristics and geometry with higher c/m ratio one can increase the initial velocity of the fragments. limitations of gurney model are also presented. more data on this topic can be found in [5,6,7,8,9,14] declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] j. a. zukas, w. p. walters, explosive effects and applications, springer, new york, 1993. [2] w. p. walters, j. a. zukas, fundametals of shaped charges, wiley-interscience publication, 1989. [3] p. p. w. cooper, explosives engineering, wiley, 1996. dss vol. 1, no. 1, december 2020, pp.16-25 25 [4] y.g. gao, s.s. feng, b. zhang, t. zhou, "effect of the length-diameter ratio on the initial fragment velocity of cylindrical casing", iop conf. series: materials science and engineering, doi:10.1088/1757899x/629/1/012020, 2019. [5] t. zulkoski, "development of optimum theoretical warhead design criteria", naval weapons center, china lake ca, 1976. [6] z. guo, g.-y. huang, c. liu, s. feng, "velocity axial distribution of fragments from non-cylindrical symmetry explosive-filled casing", international journal of impact engineering, vol 118, pp. 1-10, 2018. [7] e. hennequin, "influence of the edge effects on the initial velocity of fragments from a warhead", nasa sti/recon technical report, 1986. [8] g. randers-pehrson, "an improved equation for calculating fragment projection angle", proceedings of the 2nd international symposium on ballistics, pp. 223-226, 1976. [9] d. felix, i. colwill, e. stipidis, "real-time calculation of fragment velocity for cylindrical warheads", defence technology, vol 15, pp. 264-271, 2019. [10] y. j. charron, "estimation of velocity distribution of fragmenting warheads using a modified gurney method", thesis, faculty of the school of engineering of the air force institute of technology air training command, 1979. [11] g. huang, w. li, s. feng, "axial distribution of fragment velocities from cylindrical casing under explosive loading". international journal of impact engineering, vol 76, pp. 20-27, 2015. [12] r. m. lloyd, conventional warhead systems physics and engineering design, progress in astronautics and aeronautics, vol. 179, 1998. [13] manual of nato safety principles for the storage of military ammunition and explosives, nato/pfp unclassified, aastp-1 (edition 1), part ii, may 2006. [14] j. carleone, tactical missile warheads, american institute of aeronautics and astronautics, washington, 1993. [15] r. r. karpp, w. w. predebon, "calculations of fragment velocities from naturaly fragmenting munitions", brl, aberdeen proving ground, maryland, july 1975. [16] a. catovic, "prediction of terminal-ballistic parameters for the natural fragmentating high-explosive warheads using experimental data and numerical methods", thesis, faculty of mechanical engineering sarajevo, 2019. [17] m. crull, m. m. swisdak, "methodologies for calculating primary fragment characteristics", department of defense explosives safety board, alexandria, va, october 2005. [18] a. prytz, g. odegarstuen, e. sogstad, b. marstein, e. smedtad, "fragmentation of 155mm artillery gerande simulations and experiment", 26th international symposium on ballistics, miami, florida, september, 2011. [19] b. zecevic, j. terzic, a. catovic, s. serdarevic-kadic, "influencing parameters on he projectiles with natural fragmentation", 9th seminar new trends in research of energetic materials, university of pardubice, pardubice, april 19–21, 2006. [20] a. catovic, e. kljuno, "a novel method for determination of lethal radius for high-explosive artillery projectiles", defence technology, https://doi.org/10.1016/j.dt.2020.06.015, 2020. [21] b. zecevic, a. catovic, j. terzic, "comparison of lethal zone characteristics of several natural fragmenting warheads", central european journal of energetic materials, issn 1733-7178, vol 5(2), pp. 67-81, 2008. microsoft word 121-129_213 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.121-129 https://doi.org/10.37868/dss.v3.id213 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 121 potential utilization of the weapon system tank boat in strengthening the defense of indonesia as a maritime country agus nugraha1*, yayat ruyat2, susilo adi purwantoro3 1 faculty of defense technology, republic of indonesia defense university, indonesia 2 faculty of defense technology, republic of indonesia defense university, indonesia 3 faculty of defense technology, republic of indonesia defense university, indonesia *corresponding author e-mail: sicepe92@gmail.com received: dec. 1, 2022 revised: dec. 25, 2022 accepted: dec. 26, 2022 online: dec. 29, 2022 abstract indonesia is the largest maritime country in the world with 80 percent of its territory in the form of oceans. this makes it difficult to supervise the security and sovereignty of the republic of indonesia, especially in the maritime sector. therefore, it is necessary to design a fast catamaran concept that is good and responsive as a tool for war and security in indonesia's maritime territory. this study aims to design the concept of a tank boat type ship and a weapon system based on domestic weapons technology. the method used is the house of quality data analysis technique which is the first stage of implementing quality function deployment (qfd) in classifying user needs based on the level of importance so that a priority scale is obtained. from the results of the analysis using the quality function deployment (qfd) method, the level of user needs for ships and weapon systems on tank boats based on weapons technology is obtained by determining the benchmark performance (bp) value for the highest to lowest design characteristics. in this case, there are several main points for the desired user needs in the operational requirements and weapon systems for the tank boat object, including tank boat has a lightweight, the weapons used have high precision, weapons must be free from itar (international traffic regulations), the flexibility of weapons to be integrated with the vehicle, the main target is a vital target or vvip, and security. the results of the study indicate that there is a need for a weapon system on the tank boat to support the defense of the maritime state. this research is expected to be used as a starting point for further research related to ships and weapon systems that can be used on tank boat rides. © the author 2022. published by arda. keywords: weapon system, tank boat, quality function deployment, benchmark performance, maritime state defense system. 1. introduction indonesia is the largest maritime country in the world with 80% of its territory in the form of oceans. the total area of indonesia reaches 7.81 million km² of which 2.01 million km² of land area, thus the area of the indonesian territorial sea reaches 3.25 million km² and the sea area of the exclusive economic zone (eez) reaches 2.55 million km² [1].the dynamics of the development of the strategic environment, both global, regional, and national, always bring changes to the complexity of threats and challenges to national defense [2]. the complexity of the threat can be seen from the type, perpetrator, and source of the threat. the types of threats and challenges are no longer dominated by military threats, but also by non-military threats. threat actors are not limited to state actors, but also non-state actors. both of them can be a threat (hybrid threat) that dss vol. 3, 2022, pp.121-129 122 is an actual or potential threat. the existence of the nation and state is at stake to face these threats, including indonesia. therefore, the national defense policy should be able to face the threats posed by the dynamics of the development of the strategic environment, both nationally, regionally, and internationally. quite a several foreign warships were detected late and entered indonesia as a result of the lack of supervision of indonesia's maritime territory. these conflicts can cause conflicts between countries, especially indonesia and other countries, which can eventually heat up and trigger military resistance. this is a special task for the state and the tni to maintain security and sovereignty in the maritime sector by providing regional defense in the form of military attacks using indonesian alusista to the opposing party. it takes a strong fleet to repel their presence so that the problem does not recur. to enforce a security system at sea, the system must be built using the principle of synergizing forces between all agencies implementing security enforcement at sea. this synergy will create unity in the organizational structure, mechanisms, and procedures for implementing security at sea carried out by its officers with the ultimate goal of upholding sovereignty and sovereign rights as regulated in unclos 1982 [3]. the criteria for fulfilling the operational requirements for tank boats include being able to operate in indonesian waters, and being faced with the implementation of the marine defense strategy, which is used as a guideline in deploying operational elements including tank boats so that they can have firepower weapons against targets at sea. sea level and strategic targets on land that are deadly, where their presence will have a large deterrence impact and adapt to the development of weapons technology. based on the fulfillment of the minimum essential force (mef) priority for the strategic plan (renstra), through presidential regulation (perpres) no. 42 of 2010, the defense industry policy committee (kkip) was formed. kkip was formed to carry out the task of fostering the domestic defense industry to formulate policies and increase the productivity of defense equipment independently. the mef, which adjust to the strategic plan or to the stages that have been made by kkip is inseparable from the management of the state defense system that must be fulfilled by the government, in this case not only the fulfillment of the main weapon system equipment (alutsista) but also the alutsista modernization program [4]. the chronology of the "antasena" tank boat program began with an oral statement from the indonesian minister of defense, mr. gen. tni (ret.) ryamizard ryacudu about his interest in the tank boat program when the tank boat model was displayed at the armored vehicle asia (ava) conference in april 2015. work the tank boat was realized in collaboration with the indonesian defense industry (pt. pindad and pt. lundin banyuwangi) with cmi defense from belgium. with a memorandum of understanding between pt. pindad (persero), pt lundin, and cmi defense s.a which was held on september 10, 2015. the use of the alutsista tank boat has a very strategic meaning because the threat to state sovereignty, especially in the field of transnational crime and infiltration from outside the territory of indonesia through a 12 nautical mile territorial area is very high. the indonesian archipelago bordering neighboring countries is close to each other and requires extensive patrol monitoring. therefore, security vulnerabilities across territorial sea borders, if only rely on the capabilities of the tni-al, polairud, or other marine security institutions. with so many straits, bays, or sea boundaries that have a level of security threat and traffic that is vulnerable to the presence of security elements, it is necessary to develop and initiate other dimensions that cannot be separated from the duties of the tni by law 34 concerning the tni. the role of the infantry unit at the level of the infantry battalion can help increase the level of security in the 12 nautical mile territory if it is equipped with a tank boat with an adequate firing range. furthermore, during the presentation of the tank boat program to the minister of defense on january 6, 2016, the minister of defense expressed full support for the tank boat program to be realized and realized where funding is planned from the ministry of defense through apbn-p. director general pothan kemhan conveyed to the president director of pt. pindad on march 8, 2016, about the planned funding support and assignment of tank boat prototype development activities which were followed up with a cooperation agreement between pt. pindad and pt. lundin on 10 june 2016, which arranged the contribution of each party to the tank boat program. the innovation of a system for purchasing military weapons equipment is very important because it aims to reduce the burden of foreign exchange and the effect on the balance of payments, thereby stimulating the development of the domestic defense industry. the choice of weapons has a very political impact, if there are conditions that hinder the development of a defense posture such as an embargo, then innovation and planning dss vol. 3, 2022, pp.121-129 123 are needed to design an independent weapon system because this is an important part of the transition mechanism for procurement and replacement of weapons systems [5]. organizationally, the infantry battalion is divided into six types of infantry battalion based on three typologies of the area, namely urban, mountain forest and sea, river, and coastal swamps. for infantry units to be able to carry out tasks in various areas of the republic of indonesia, transportation equipment in the water is needed that can operate effectively and efficiently with reliable maneuvers and maximum firepower in these areas. based on the above background, the researcher formulates the problem and makes the research question, namely how is the potential utilization of the weapon system tank boat in strengthening the defence of indonesia as a maritime country? to answer the formulation of the problem above, the researcher uses several theories related to the potential utilization of the tank boat weapon system in strengthening indonesia's defense as a maritime state. in seeing the potential use of the tank boat weapon system in strengthening indonesian defense, a strategy is needed to maximize the utilization of the resources owned. by definition, strategy is an action or activity carried out by an organizational leader in achieving the goals that have been set by using the resources they have. strategy theory is more planning (planning) which connects all existing aspects (means) and uses them optimally [6]. strategy talks about schemes and steps to achieve a goal. carl von clausewitz's opinion in his book on war states that strategy is the use of engagement for war. the strategy focuses on the use of strength in carrying out engagement efforts to achieve goals. strategy theory explains how to determine goals for all existing elements to support the process of achieving goals. the existence of a strategy is very important to guide steps in the development of an uncertain situation. the strategy assumes that the future cannot be predicted but that the strategic environment can be studied and accessed to be able to formulate anticipatory steps. adds if the strategy is implemented by applying ends, ways, and means in a strategic environment to achieve the desired goals [6]. ends is an objective or goal to be achieved by considering the variables contained in the strategic environment. these goals are contained in the policies made by the state to achieve strategic results in realizing an interest. ways is a strategic concept to answer how to achieve certain goals by applying national power (1). mathematically, strategy is assumed to be a means plus a goal, with the formula st = w + m + e with description: st (strategy) = strategy, w (ways) = the way to reach the goal, m (means) = resources, facilities, and infrastructure that can be used to achieve goals, and e (ends) = goals defined in the policy. this conception will narrow down to the question of who does what, where, when, how, and why. the strategic concept must be able to provide guidelines for the implementation and implementation of national power to achieve national goals. in formulating a strategy, of course, one must take into account in detail measurable related ends, means, and ways. this is important for success in achieving goals. the means are a limitation for the type and level of supporting elements in encouraging the achievement of a goal. in strategy, means can be tangible or intangible. for example, tangible means include forces, people, equipment, money, and other supporting facilities. meanwhile, intangible means include a will, courage, spirit, and intellect [6]. the development of technology, especially technology in the field of weapons, has become a threat that is realized through an increasingly strong military force, considering that countries in the world are currently trying to allocate defense budgets for the sake of increasing and developing their military strength as the main mission of self-defense (self-defense). research on weapons technology and the purchase of high-tech military equipment from other countries. threats are the main factors that form the basis for drafting the design of the national defense system, both actual and potential. state defense efforts are carried out through the development of the national defense posture. the development of the national defense posture is carried out on an ongoing basis to realize strength, capabilities, and titles. the development of the military defense posture is directed at fulfilling the minimum essential force (mef) of the main components and preparing other defense components. the military defense posture consists of main components, reserve components, and supporting components, which are directed through building strength, abilities, and titles. the military defense posture is prioritized to deal with actual threats by not ruling out potential threats and other threats. in the 2015 defense white paper of the republic of indonesia, it is explained that the tni's posture includes 3 things, namely strength, ability, and title. in the context of the use of the tank boat weapon system in strengthening indonesia's defense as a maritime country, it requires development in the aspect of equipment developed through various plans. quality function deployment (qfd) is a method used to develop and plan products so that the development team can specify in detail the needs and desires of customers [7]. meanwhile, daetz explains that qfd is a systematic planning dss vol. 3, 2022, pp.121-129 124 process created to help companies organize all the elements needed to define, design, and manufacture products or provide services that can meet customer needs [8]. broadly speaking, quality function deployment is a systematic planning process that was created to help an agency or company to be able to manage all elements that can design, define, and create products or provide a service that can meet customer needs. the main tool of qfd is the arrangement of matrices by collecting, interpreting, documenting, and prioritizing customer requirements. the starting point for qfd is the customer and the wants and needs of the customer (voice of the customer). the qfd process starts with customer needs and then continues through 4 main points, namely product planning, product design, process planning, and process control planning. in addition, there is a house of quality, which is the first stage in implementing qfd, formed by compiling one or more matrices that are interconnected and developed to determine the relationship between customer needs and technical parameters of the product or service. this matrix explains what the customer's needs and expectations are and how to fulfill them. the stages in implementing it are through 3 phases, namely the first phase by collecting customer needs (voice of customer), the second phase by compiling the house of quality, and the third phase of analysis and interpretation of the previous stages. this phase is carried out in various ways in each phase. research with the same topic is not widely carried out, but there is one study that discusses the optimization of the shape of the catamaran ship demihull to improve the quality of seakeeping which is also discussed in this study, but this research has differences in the optimization of the shape of ship demihull to improve the quality of seakeeping following the standards of general seakeeping criteria for military ships. the demihull form used is npl hull form series 4b 2. research method this study uses a qualitative method with an emphasis on an object in this case the tank boat. research using the qualitative method is defined as a research procedure that produces descriptive data in the form of written or spoken words from people [9]. one of the research designs that can be used in qualitative research and is considered suitable for this research is the case study approach, namely the design of the weapon system on the tank boat through the system engineering approach. the research design that is used as a reference is considered suitable because it is following the theory from the design system engineering approach book [10] which states that to carry out development, research must at least have standard stages starting from the user need phase, conceptual design, preliminary design, detail design, production/construction, and product use, support, and disposal. this research focuses on conceptual design with the implementation of the system life cycle in the acquisition phase including user needs and conceptual design. 3. results and discussion the potential use of the tank boat weapon system in strengthening indonesia's defense as a maritime country. 3.1 platform “tank boat” after obtaining the criteria from the operational requirements, then the determination of the platform of the “tank boat” is based on the number of components that will be installed on the ship. the components that will be installed on “tank boat” can be seen in table 1. table 1 platform “tank boat” components no component amount dimensions l x b x h (mm) weight (kg ) 1 main engine 1 dimensions [p × p × t] (mm) 1812x1293x1414 2300 2 thermal camera 1 15.18" x 18.68" x 50 x 30 30 3 turret 1 12 m 4000 4 life raft 2 900 x 550 x 380 56 5 navigation bridge sistem 1 according to spesification 250 6 rgb 1 p=7800, w=2500 450 7 battery 12 v 8 578 x 254 x 219 200 8 thrust vectoring 1 suitable for turbojet engines 200 9 ae 2 1029 x 629 x 251 824 dss vol. 3, 2022, pp.121-129 125 10 frest water 2 in accordance ga 100 11 fuel oil 10 in accordance ga 142 12 diesel oil 2 in accordance ga 428 13 crew 4 360 total weight 8320 table 1 shows the number of components along with their dimensions and total weight. the total weight of this component will be used as the ship's payload. so the payload of the tank boat is 8320 kg. 3.2 ship design stages the process of designing a ship is iterative, that is, all planning and analysis are carried out repeatedly to achieve maximum results when the design is developed. the spiral design is divided into 4 stages, namely: concept design, preliminary design, contract design, and detail design [11]. in this study, the design of the catamaran tank boat warship was only limited to concept design. therefore, the design process discussed is only a concept design. figure 1. spiral design stages [12] there are four stages in this design spiral, including the following. 3.2.1 concept design concept design is an advanced stage after the owner's requirement. the concept of ship design is the designer's task to define an object to fulfill mission requirements and comply with existing constraints/problems. to create a concept, approach formulas, curves or experience are used to make initial estimates that aim to get an estimate of the cost of building a ship. the results of this design concept stage are generally in the form of drawings or sketches, either partially or completely 3.2.2 preliminary design preliminary design is the second stage in designing the ship. preliminary design is a further technical endeavor that will give more detail to the design concept. in conjunction with the spiral diagram, the preliminary design is the second iteration or the second path in the spiral diagram. what is meant by detail includes features that have a significant impact on the ship, including the initial approach to the costs required. examples of adding details are the calculation of the longitudinal strength of the ship, the development of the midship section of the ship, a more accurate calculation of the weight and center of gravity of the ship, draft, stability, and others. dss vol. 3, 2022, pp.121-129 126 3.2.3 contract design the contract design stage is an advanced stage after the preliminary design stage, namely the development stage of ship design in a more detailed form that allows shipbuilders to understand the ship to be built and accurately estimate all shipbuilding costs. the main purpose of the design contract is to produce a document that describes the ship that will be built soon. furthermore, these documents will be the basis of the contract or development agreement between the ship owner and the shipyard. the components included in the contract design are as follows: (1) arrangement drawing, (2) structural drawing, (3) structural details, (4) propulsion arrangement, (5) machinery selection, (6) propeller selection, (6) generator selection, (7) electrical selection. the components above are also known as key plan drawings. the key plan drawings must present in detail the ship's features according to the request of the ship owner or ship owner. 3.2.4 design details detail design is the last stage of the process of designing a ship. at this stage, the results of the previous stages will be developed into a more detailed working drawing as a whole. ship construction plans will be discussed in detail at this stage. the biggest part of this process is the production of working/field drawings required in the production process. the purpose of this tank boat design is to determine the operational requirements of the catamaran combat boat assault warship, obtain the main size of the catamaran tank boat assault warship and obtain the lines plan and general plan of the catamaran tank boat assault warship with turbojet. before entering the calculation process and the design stage, it is necessary to plan the criteria that will be used for the tank boat starting from the criteria that have the most influence on the design process. the criteria are the type of hull and material. for a detailed explanation, see the following sub-sections: 3.2.5 hull type from the decision tree image, we get three types of hulls as the preferred candidate for the tank boat. the three types of hulls have advantages and disadvantages, as follows: 1) monohull is a hull monohull type that has shortcomings in terms of stability, easy rolling, and relatively small deck area figure 2. mono hull [13] 2) the catamaran has the advantages of a catamaran hull compared to a monohull hull, namely: a) large deck area. b) can maintain speed in the sea with high waves. dss vol. 3, 2022, pp.121-129 127 c) have a stable platform. d) more cost-effective than other hull types with the same capability. figure 3. multi-hull catamaran based on the research of prof. jacob van renen van niekerk who already has experience and expertise in the shipping field, the fully asymmetric type c catamaran hull has the advantage that it is suitable for the design of the tank boat catamaran. some of the advantages of a fully asymmetric type c hull are described as follows [14]: (a) the wave interference in the bridge section is smaller than that of a symmetrical catamaran (b) can sail well even in waters with high waves and can slide sideways safely when the ship changes direction drastically. (c) very good stability (will reverse only if there is a very large increase in load. 3.3 material two types of material are obtained as the preferred candidates for tank boats, namely the type of material system that has advantages and disadvantages, as follows: 3.3.1 carbon fiber composite this type of material has the characteristics of lightweight material, can be stronger than good strength, more flexible to form, and free of corrosion. 3.3.2 aluminum the type of material that will be used for the tank boat is aluminum. several things are considered in the selection of aluminum, namely, it has been used for naval ships around the world, the material is lighter than steel, increases camouflage ability, and corrosion is 100x slower. from these considerations, the type of material to be used is carbon composite. the selection of this type of material is based on the design criteria of the tank boat to be made, where the ship must have greater strength than other ship materials. in addition, the selection of carbon composites is because this type of material has been tested and has a low density, thereby reducing the ship's load. for the tank boat design that is more supportive of field operations, it was chosen to use the catamaran design with a lighter carbon composite material so that operations can be carried out in shallow waters. after the previous stages have met the operational requirements, the next step in the ship design process is the process of determining the method of designing the ship. in general, the methods in ship design are as follows. a parent design approach is one method of designing ships by comparing existing ships with designs to be made, namely by taking the main size of a ship that has been previously designed with the provision that the ship must have the same characteristics as the ship to be designed, in this case, the designer already has a reference to the same ship as the ship to be designed. the advantage of the parent design approach is that it can design ships faster because there is already a reference for the ship, it only remains to repair and improve the performance of the ship, and the parent ship's performance is proven (stability, motion, resistance) model a asymmetrical model b symmetrical model c asymmetrical type-a model d asymmetrical type-a dss vol. 3, 2022, pp.121-129 128 the trend curve approach method which is often referred to as the statistical method is a method/method of designing ships by using regression from several comparison ships to determine their main size. in this method, the sizes of several comparison vessels are compared where the variables are connected and then a trend line is drawn that applies to the ship to be designed. the iterative design approach is a ship design method based on a cyclical process of prototyping, testing, and analyzing. changes and improvements will be made based on the results of testing the latest iteration of a design. this process has the aim of improving the quality and functionality of an existing design. the ship design process has an iterative nature which is most commonly described by a design spiral that reflects the design methodology and strategy. the parametric design approach is a method used in designing ships with main dimension parameters which are the results of regression from several comparison ships, then calculating the resistance (rt), designing the propellers, calculating the estimated main engine power, calculating the number of crew members, calculating the center of gravity, trims, and others. the optimization method is used to determine the optimum main size of the ship and the required motor power at the basic design stage. in this case, the optimum design is sought by finding the design that will minimize the economic cost. the parameters of this optimization are the laws of physics, cargo capacity, stability, freeboard, trim, and ship price. 4. conclusions the potential utilization of the tank boat weapon system in strengthening indonesia's defense as a maritime country is using the quality function deployment (qfd) method, determining customer requirements is the most important and fundamental part of explaining the needs desired by users in this case, namely the indonesian army. these needs include the operational requirements that must be possessed by a tank boat to carry out its mission as a combatant as well as the weapons system requirements used. in this case, there are several main points for the desired user needs in the operational requirements and weapon systems for the tank boat object, including: a) tank boat is lightweight. b) the weapons used have high precision. c) weapons must be free from itar (international traffic regulations). d) the flexibility of weapons to be integrated with the vehicle. e) the main target is a vital target or vvip. f) security. from the results of the analysis using the quality function deployment (qfd) method, it was obtained the level of user needs for ships and weapon systems on tank boats based on domestic weapons technology produced by the private and national defense industries, namely pt lundin, pt len, pt hariff, and pt. pindad by determining the benchmark performance (bp) values for the highest to lowest design characteristics shows the results of the benchmark performance and priority scale values that have been sorted and arranged, namely design characteristics that have priority scales in order. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] roza, e. "maritime indonesia, extraordinary luxury", https://kkp.go.id/artikel/2233-maritim-indonesiakemewahan-yang-luar-biasa, 2017 (acessed on 27 march 2022). [2] national defense policy, https://ppid.kemhan.go.id/assets/attachments/20210721_57jakhanneg-2021-oke, (accessed on 23 january 2022). dss vol. 3, 2022, pp.121-129 129 [3] soedewo a., "enforcement of provisions for foreign-flagged ships to pass in indonesian archipelagic sea lanes (alki) ii viewed from the perspective of indonesian state law and united nations convention on the law of the sea (unclos) 1982", student journal of the faculty of law, university of brawijaya, 2015. [4] bpkp b. p, "presidential regulation (perpres) number 42 of 2010". jakarta: sekretariat kabinet republik indonesia, 2010. [5] prasetyo t. a, "kkip performance evaluation in republic of indonesia-south korea cooperation in submarine development to support resilience", journal of national resilience, vol 23, no 21, pp 88-89, 2017. [6] yarger h. r., strategic theory for the 21st century: the little book on. usa, blackswell publisher, 2006. [7] cohen l, quality fuction deployment: how to make qfd work for you, addisonwesley publishing co, massachusetts, 1995. [8] daetz d. b, customer integration: the quality function deployment (qfd) laders guide for decision making, john wiley & sons inc, new york, 1995 [9] moleong l. j, qualitative research methodology, pt rosdakarya, bandung, 2018. [10] sadraey m. h, aircraft design a system engineering, john wiley & sons, usa, 2013. [11] watson d. g, practical ship design, elsevier, vol 1, 1998. [12]naval architects australia, retrieved from web link navalarchitectsaustralia.blogspot.com: https://navalarchitectsaustralia.blogspot.com/. [13] zubaer h., u. b, "twin step hull variation analysis on a 15-meter alu pilot boat using the cfd method", jurnal teknik perkapalan, 2018. [14] niekerk j, "comparison of catamaran hull type", issue of power multihull magazine, 2000. microsoft word 1-7_216 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.1-7 https://doi.org/10.37868/dss.v4.id216 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 1 analysis of spbe and swcsf measurement instruments using flesch reading ease for state security meylia susiana dewi putri1*, rudy ag gultom2, achmad farid wadjdi3 1,2,3 republic of indonesia defense university, faculty of defense technology, indonesia *corresponding author e-mail: meylia.putri@idu.ac.id received: dec. 8, 2022 revised: jan. 3, 2023 accepted: jan. 7, 2023 online: jan. 11, 2023 abstract the world has transitioned into a digital era where both individuals and governments require technology and the internet. the number of cybercrimes perpetrated online is impacted by the rising usage of computers and the internet. a measurement instrument that can stop cybercrime is necessary. the six-ware cyber security framework (swcsf) and the electronic-based government system (spbe) are two measurement tools that are expected to be able to stop cybercrime from happening in an agency or organization. but are all people able to use these two instruments? this research was conducted to answer this question by analyzing readability on the spbe and swcsf instruments using the flesch reading ease method. the results show that the two instruments were extremely difficult for respondents of all grade levels to comprehend, with the exception of those at the university level or individuals who worked with computers, the internet, and other technologies. © the author 2023. published by arda. keywords: spbe; swcsf; measurement instrument; flesch reading ease; digitalization 1. introduction the industrial revolution 4.0 has affected all disciplines, including the sphere of information and technology, and indonesia, which is entering it, appears to have developed a strategy to prepare for it (science and technology). the indonesian people have adopted this transition as a trend and way of life. the industrial revolution era's legacy includes society's growing reliance on information and communication technology. the digital era is one example of how technology and information have advanced. the digital revolution has arrived in indonesia, where information can now be found online and through websites. this is seen in the rising and increasingly sophisticated demand for technological devices. the transformation of traditional government into electronic government (e-government) is a public policy regulated in article 28f of the 1945 constitution. the development of e-government has a vision, namely a review based on broadband networks, electronic document systems, information sharing, and government portal websites. the indonesian government is currently developing an electronic-based government system [1]. the use of e-government in indonesia aims to improve performance and productivity, improve budget efficiency, and increase transparency and accountability in the delivery of service activities to the community [2]. therefore, the implementation of e-government in government must be carefully prepared and integrated dss vol. 4, 2023, pp.1-7 2 between bureaucratic systems and policies so that they can be well received by service users, namely the community and internal government. in the context of e-government, user trust in using public services is important because it can make people feel comfortable using e-government [3]. the development of e-government that utilizes information and communication technology (ict) must pay attention to the ict and cybersecurity policies applied. in the current era, the development of ict and digitalization is directly proportional to the increase in ict crimes and cybercrimes. based on a report from [4], indonesia accounts for 40% of the asean population with a gross domestic product proportion of around us$ 4,174.9. indonesia is estimated to spend 1.6% of gdp in digital infrastructure, compared to malaysia at 4.5% and singapore at 6.6%. this shows that there is room to accelerate cybersecurity in indonesia. a new challenge to the system is brought about by the growth of the government's computerized system. akhmad toha (2021), deputy for bssn protection, stated at the huawei techday event that in order to realize an accountable, transparent, and democratic government system, the governance of an electronic-based government system (spbe) must be supported by strong cyber security. cyber attacks can cause disruption and damage to network systems that connect, integrate, synchronize, and control computerized and integrated government equipment and infrastructure [5]. in 2019, indonesia was one of the countries with the highest recorded cases of malware attacks in the asia pacific region. the potential economic loss in indonesia due to cybersecurity incidents could reach us$ 34.2 billion [6]. these problems can be prevented by measuring the level of cyber security and information and communication technology using measurement instruments. two measurement tools that make use of information and communication technology (ict) resources that can be employed in the central and regional domains are the spbe and swcsf. the authority for ict development focuses on the balance of central and local authority, alignment of planning, and coordination of implementation. currently, indonesia is experiencing the covid-19 pandemic, which has changed the system from manual to digital [1]. changing systems requires building skills within the organization with the aim of helping them cope with and adapt to new circumstances. therefore, in measuring the progress of implementation and readiness of spbe and swcsf, it is assumed that there will be different results. from this statement, a measurement framework that contains complexity and diversity is needed for all instruments. the application of spbe aims to measure the implementation of national ict policies within an agency. research conducted by gultom et al [5] is the current implementation of swcsf is in defense institutions such as the cyber defense center of the ministry of defense (pushansiber kemhan) and the ministry of defense information data center (ind. pusdatin kemhan). the application of swcsf aims to measure an agency's readiness for cybersecurity. instrument portability is an important part of determining whether a model or measurement system is simple to implement, and it is also related to the effectiveness and efficiency of resource use. portability is the ease with which the instrument is moved from one place to another [7]. portability can be defined as the ease with which the instrument is used by all users. trishadiatmoko [8] used statistical analysis to perform a portability analysis on the spbe instrument. this study was conducted to analyze the portability of the spbe and swcsf measurement instruments. one of the methods to measure the portability of the instrument is by analyzing the readability of the questionnaire that will be distributed to the respondents. 2. research method this research was conducted using qualitative methods with a descriptive analysis approach. this study analyzed the readability of the spbe and swcsf instrument questionnaires using the flesch reading ease. generally, this method is used to analyze the readability of a book, magazine or essay. anita [9] used this method to analyze the readability of grade 12 english textbooks. research data are statements or questions displayed on the questionnaire that will be distributed to respondents. the questionnaire that was distributed was a measurement instrument that was carried out digitally because it was distributed online via a link. this dss vol. 4, 2023, pp.1-7 3 indicates that the analysis using this method is very important to do to find out which categories of respondents are suitable for filling out the spbe and swcsf questionnaires. the calculation results obtained using flesch reading ease are then matched with the reference table in table 2 to see the categories of the data results. then, the results obtained using the flesch-kincaid grade level will be seen in the reference table (table 1) to see the categories of the data results. table 1. flesch-kincaid grade level categories [10] score notes 90 – 100 comprehensible to the average 11-year-old kid 60 – 70 13to 15-year-old children can understand it with ease 0 – 30 university grads are more likely to understand table 2. flesch reading ease categories [10] raw score difficulty level < 30 very difficult 30 – 50 difficult 50 – 60 fairly difficult 60 – 70 standard 70 – 80 fairly easy 80 – 90 easy 90 – 100 very easy the questionnaire that will be distributed to respondents contains statements and questions regarding indicators from the spbe and swcsf. these questions and statements constitute data that will be analyzed to calculate the readability score and grade level generated by the questionnaire. these questions or statements will be grouped according to the indicators contained in the spbe and swcsf. the flow chart of analysis data can be seen in figure 1. figure 1. data analysis flow 3. results and discussion the electronic based government system (spbe) and six-ware cyber security framework (swcsf) are two measurement instruments that utilize information and communication technology (ict) used in central and regional domains. spbe is used to measure the implementation of national ict policies in agencies. ict make a list of statements for the spbe and swcsf questionnaires count the number of words and sentences in the sample perform reading level analysis using the flesch reading ease formula perform grade level analysis using the flesch-kincaid grade level formula the resulting data is described dss vol. 4, 2023, pp.1-7 4 policy in an agency must be supported by the agency's readiness for cyber security because, in today's digital era, the use of technology must be supported by knowledge about cybercrime. the swcsf instrument can be used to assess agency readiness for cyber security. the development of ict continues to increase, so the level of cybersecurity needs to be increased. so, it can be said that the two measurement instruments can support each other in preventing cybercrime in today's digital world. table 3. assessment indicators for electronic-based government systems [8] no. indicators 1. governance policy 2. service policy 3. institutional 4. strategy and planning 5. information and communication technology 6. administrative services 7. public service the measurement instruments used in the spbe and swcsf are in the form of a questionnaire consisting of several indicators. the spbe instrument has seven determining indicators in the assessment, which can be seen in table 3, and the swcsf instrument has six determining indicators, which can be seen in table 4. table 4. assessment indicators for six-ware cyber security framework [11] factors definition indicators brainware human factor security awareness hardware physical computers and peripherals no compromises software operating system and applications no pirated appl. etc. infrastructureware physical and logical network infrastructure no network security breaches, etc firmware document and procedures good bussiness pro-cesses budgetware an estimate of income and expenciture for a set period licences always updated, etc the portability of these two instruments must be taken into account. the portability of an instrument refers to its ease of use by individuals or institutions. in other words, every individual or institution is capable of and understands using the instrument. one of the requirements for a measuring instrument to be considered portable is its readability. spbe and swcsf are instruments in the form of a questionnaire, so what is meant is the readability of the respondents to the statements or questions given. if the statement is easy to read, then the respondent understands the statement. the reading ease measurement uses the flesch reading ease and flesch-kincaid grade level methods. the formula used to calculate it is as follows [12]: 𝐹𝑅𝐸 = 206.835 − (1.015 𝑥 𝐴𝑆𝐿) − (84.6 𝑥 𝐴𝑆𝑊) (1) 𝐹𝐾𝐺𝐿 = (0.39 𝑥 𝐴𝑆𝐿) + (11.8 𝑥 𝐴𝑆𝑊) − 15.59 (2) where : fra: flesch reading ease, fkgl: flesch-kincaid grade level, asl: average sentence length, asw: average number of syllables per word. dss vol. 4, 2023, pp.1-7 5 some examples of statements and questionnaire questions used are "apakah unit kerja anda memiliki kebijakan terkait perencanaan dan penganggaran (rengar) tik?" the sentence consists of 12 words and 33 syllables. the sentence " menurut saya, instansi perlu adanya peraturan, perjanjian kerjasama dalam menjaga keamanan data dan informasi". the sentence has 14 words and 40 syllables. the data is obtained by counting the number of sentences, words and syllables for each measurement indicator. the results obtained from these data can be seen in table 5 for the spbe instrument and table 6 for the swcsf instrument. table 5. result of spbe instrument indicator number of sentences number of words number of syllables asl (x1) asw (x2) fra (y) fkgl 1 7 78 214 11,14 2,75 -37,12 21,20 2 10 116 340 11,60 2,93 -53,23 23,57 3 2 19 45 9,50 2,37 -3,18 16,06 4 2 22 55 11,00 2,50 -15,83 18,20 5 3 28 74 9,33 2,64 -26,22 19,24 6 7 58 166 8,29 2,86 -43,71 21,41 7 4 43 105 10,75 2,44 -10,66 17,42 average -27,13 19,59 the readability values for the spbe and swcsf instruments are -27,13 and -39,28, respectively. this score falls under the "extremely difficult" category according to table 2. some responders may find it quite challenging to understand the level of understanding required by the distributed questionnaire. table 6. result of swcsf instrument indicator number of words number of syllables number of sentences asl (x1) asw (x2) fra (y) fkgl 1 95 268 8 11,88 2,82 -43,88 22,33 2 58 148 5 11,60 2,55 -20,81 19,04 3 36 95 4 9,00 2,64 -25,55 19,06 4 73 196 5 14,60 2,68 -35,13 21,79 5 71 184 3 23,67 2,59 -36,43 24,22 6 60 173 4 15,00 2,88 -52,32 24,28 7 79 225 3 26,33 2,85 -60,84 28,29 average -39,28 22,72 the results of the flesch-kincaid grade level computation, which used the results of the two instruments, show that this is true. the spbe instrument's score was 19,59, and the swcsf instrument's score was 22,72 as you can see in figure 2. the two scores fall under the "best understood by university graduates" category, according to table 1. the two surveys will be provided to respondents who have a high level of knowledge, and it can be said that they are best suited for those who have completed college. the fkgl value obtained by swcsf is greater than that obtained by spbe. even though the two instruments are in the same category, this indicates that the swcsf instrument is more portable than the spbe. dss vol. 4, 2023, pp.1-7 6 figure 2. grade level of spbe and swcsf 4. conclusions spbe and swcsf measurement instruments are two important instruments to be used in today's digital era. measuring policies on the use of ict and cybersecurity in an agency or organization is necessary for the prevention of cybercrime. the instruments displayed from spbe and swcsf are in the form of questionnaires, which will be distributed to respondents. thus, the respondent's understanding of the questions or statements in the questionnaire is important. the respondent's understanding begins with the ease with which the respondent reads the questionnaire. according to the results, the respondent's grade level is university level, and both the spbe and swcsf instruments are highly challenging to understand. the spbe and swcsf instruments can be completed by respondents who work with computers, the internet, and other technologies in settings other than higher education. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] m. h. muttaqin, t. d. susanto, "the effect of website components on user trust in increasing the interest to use public administration service on e-government website," 2019 international conference on computer science, information technology, and electrical engineering (icomitee), pp. 30-36, 2019. [2] f. novianto, “electronic government development strategies using frameworks cobit 5”, proceeding international conference on science and engineering, vol 3, pp. 263-271, 2020. [3] h. m. al-saghier, m. ford, a.l. nguyen, r. hexel, “conceptualising citizen's trust in e-government: application of q methodology”, electronic journal of e-government, vol. 1, pp. 204-230, 2009. [4] australian cyber security growth network (austcyber), “cyber security opportunities in the asean region,” australian cyber security growth network, canberra, 2019. [5] r. a. gultom, f. a. lestari, c. lahallo, r. n. akbar, “pengembangan teknologi pertahanan berbasis cyber dari sixware cyber framework untuk meningkatkan penyelenggaraan sistem pertahanan negara di kota batam”, int. j. adv. sci. teknologi., vol. 29, pp. 3431-3436, 2020. [6] l. n. amali, m. r. katili, s. suhada, l. hadjaratie, “the measurement of maturity level of information technology service based on cobit 5 framework”, telkomnika (telecommunication computing electronics and control), 18(1), pp. 133–139, 2020. 19.59 22.72 18 19 20 21 22 23 spbe swcsf g ra de l ev el measurement instrument dss vol. 4, 2023, pp.1-7 7 [7] j. a. mccall, p. k. richards., g. f. walters, “factors in software quality volumes i, ii, and iii”, us rome air development center reports, us department of commerce, usa, 1977. [8] p. trishadiatmoko, a. f. wadjdi, “public policy implementation during pandemic covid: modifying the measurement framework of the electronic-based governance system for various organization levels of indonesia public service broadcasting (tvri)”, ranepa: aapa, 2021. [9] a. firdaus, “the readability level of reading texts in english textbook entitled bahasa inggris for senior high school students grade xii”, unusa, 2020. [10] w. dubay, “smart language: readers, readability, and the grading of text”, costa mesa: impact information, 2006. [11] r. gultom, cyber warfare : sudah siapkah kita menghadapinya?, unhan press: bogor, 2019. [12] n. hikmah, t. o. sanerita, j. t. ignatius, “the readability level of reading texts in the english textbook entitled when english rings a bell for the seventh grade junior high school”, kompetensi: jurnal ilmiah bahasa dan seni, pp. 368-376, 2021. microsoft word 96-111_175.docx issn 2744-1741 defense and security studies original research vol. 2, may 2021, pp.96-111 https://doi.org/10.37868/dss.v2.id175 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 96 turbulent flow height measurement with stereo vision ajdin jašarević1, marko hočevar1, gašper rak2 1 faculty of mechanical engineering, university of ljubljana, slovenia 1 faculty of civil and geodetic engineering, university of ljubljana, slovenia *corresponding author: ajdinjasarevic1995@gmail.com © the author 2021. published by arda. abstract this paper describes the process of 3d analysis of two water currents with method of photogrammetry. photogrammetry is used in fields such as architecture, engineering, police investigation, preserving cultural heritage, military and geology. this method can be used in military to reconstruct a site with traces of shrapnel or various projectiles. in our case we tried to measure height of turbulent flow, where two currents collided at the angle of 90°. in first section we introduce our problem and method. second section describes method of photogrammetry and basics of torrential flows. in third section we describe our experiment. fourth section describes the course of getting 3d model. in fifth section we analyze results and in sixth section, a conclusion is given. keywords: torrential current; confluence of currents; 3d reconstruction; photogrammetry; 3d models 1. introduction with the existence of several types of measurement technologies and their increasing availability, approaches to measuring various phenomena in the living environment are also changing. knowing the situation at the confluence, both on watercourses (riverbeds) and on many facilities and water infrastructure (fish paths) is of great importance for users and planners of works in this environment. at the confluence of two free-surface currents with higher reynolds and froud numbers, quasi-stationary standing waves appear, the flow dynamics of which are very pronounced. in the past, these properties have been measured with tactile or pressure sensors, but they have limited temporal and spatial resolution. in paper, we determined the height of such a stream with the help of photogrammetry. at a measuring station with two perpendicular currents, we recorded a quasi-standing wave with two high-speed cameras, and with the help of images we made a 3d model of the wave after their processing and determined its height. we found that the results were not accurate enough to determine the wave height or a more detailed analysis of the topographic structure, and that more accurate results would require a larger number of cameras to contribute to more images from several different angles. 2. torrential flow and photogrammetry in this section we will describe basics of torrential flow and photogrammetry. 2.1. torrential flow in free-surface flow, different flow regimes occur (subcritical, critical and supercritical). these regimes can transition from one to the other on shorter sections. at the available cross-sectional energy and at a given flow q, a critical depth or one of the two conjugate depths occurs (at subcritical or supercritical currents). at low velocities and great depths, potential energy predominates. such a flow is called a steady or subcritical flow. at high speeds and shallow depths, kinetic energy predominates. such a flow is called a supercritical or dss vol. 2, may 2021, pp.96-111 97 torrential flow. it is characteristic of a subcritical current that the water moves slower and the current conditions are more affected by the downstream conditions, while in the case of a supercritical flow, the conditions are more affected by upstream conditions. at the transition from supercritical to subcritical flow and vice versa, a strongly turbulent flow occurs, which we call a water jump. there are marked losses of kinetic energy in the water jump. the first equation describes the depth for subcritical flow and the second for supercritical flow [1], [2]: depth of subcritical flow: ℎ = 𝑣 2𝑔 2 + 𝑣 2𝑔 4 + 𝑣 2𝑔 ∗ ℎ (1) depth of supercritical flow: ℎ = 𝑣 2𝑔 2 + 𝑣 2𝑔 4 + 𝑣 2𝑔 ∗ ℎ (2) the following equation states the condition for the occurrence of critical quantities of water flow, by means of which the critical depth can be calculated [1]: 𝑄 𝑔 = 𝑆 𝐵 (3) in equations, ℎ represents depth at subcritical flow, ℎ is depth at supercritical flow, 𝑣 stands for velocity at subcritical flow, 𝑣 represents velocity at supercritical flow and 𝐵 stands for surface width at critical flow. the free-surface flow regime is described by the dimensionless froud number (fr). the froud number allows to describe the ratio of inertia and gravity forces, and is used to describe and model the free-surface flow caused by the component of the force of gravity in the downstream direction. we usually neglect the influence of viscous, surface and capillary stresses, if the models are not miniature, but if we take into account geometric similarities and similarities of boundary conditions, we can also achieve similarity of friction forces [2], [3]. 𝐹𝑟 = 𝜌𝑣 𝑙 𝜌𝑔𝑙 = 𝑣 𝑔𝑙 = 𝑖𝑛𝑒𝑟𝑡𝑖𝑎 𝑓𝑜𝑟𝑐𝑒𝑠 𝑔𝑟𝑎𝑣𝑖𝑡𝑦 𝑓𝑜𝑟𝑐𝑒𝑠 (4) in equation (4) 𝑔𝑙 is the travel velocity of the gravitational wave, 𝑙 is the characteristic flow length and 𝑣 is the water flow velocity. the larger the froud number, the smaller the influence of gravitational forces and the greater the influence of current kinetics, and conversely, the smaller the fr, the greater the influence of gravitational forces [3]. froud number gives information about the velocity of the flow in the flow, so it can be used as a measure of the water flow regime [2]. according to the value of fr, the flow is divided into: fr < 1 (subcritical flow), fr = 1 (critical flow), fr > 1 (supercritical flow). in this research we are dealing mainly with 3d analysis of supercritical flow. 2.2. photogrammetry photogrammetry is a method of obtaining reliable information about the properties of surfaces and objects without physical contact with objects and measuring and interpreting this information. in addition to processing and interpreting photographs, photogrammetry today also includes the processing of videos, images from laser scanners, x-ray images, magnetic resonance images, ir images and various devices such as sonar, radar, etc. the main purpose of photogrammetry in all the mentioned applications is to obtain 3d data dss vol. 2, may 2021, pp.96-111 98 from 2d photos or videos. many analog, tactile, non-tactile, ultrasonic and optical methods and, above all, analytical techniques are used for this purpose. with the development of computing and with increasing processing power, the boundaries of application and accuracy of photogrammetry are moving towards increasingly realistic representations [4], [5]. 3. experiment a measuring station was made at the faculty of civil engineering and geodesy in ljubljana years ago, which replicates the conditions at the confluence of two flows in the natural environment, and is comparable to previous researches. the water comes to station from two channels, the main and the side channel. main stream is a total of 6 m long and 0.5 m wide. side channel is also 0.5 m wide and 1 m long. the confluence of two streams therefore occurs 1 m after the water enters the side stream and this length was chosen in order to stabilize the flow at the entrance and to achieve the same conditions on both lines before the confluence. the conditions at the test site with dimensions in mm are shown in figure 1. figure 1. conditions at the test site with dimensions water flow in both channels was measured with separate flow meters installed at inlet channels of both flows. above the side channel, a metal stand is installed, which serves to stabilize the cameras, in order to minimize the vibrations that can be caused by the current. 3d sketch of test facility is shown in figure 2. to prevent reflections of light we installed black matt foil on glass surface of testing facility. figure 2. 3d sketch of test facility area of measurement side channel inlet m ain channel inlet o utlet flow meter side inlet channel main inlet channel high speed cameras dss vol. 2, may 2021, pp.96-111 99 3.1. high speed cameras two photron high-speed cameras were used to control the number of frames per second (fps), the aperture time and the moment of photo capture, all parameters were selected in photron's computer software. we also synchronized the cameras so that we could set the same parameters for both cameras. we used the following cameras: photron mini ux100 800k black-white and photron mini ux100 800k colour. both cameras enable the mounting of lenses according to c and f standards and the mounting of the housing on standard three-axis photo heads with a din933 ¼ '' 20 unc inch screw. the cameras have 16 gb of internal memory, which is enough to record a few seconds depending on the set number of frames per second, resolution, etc. the recordings were then transferred to a computer in .bmp format via an ethernet port with a utp cable. the synchronization and trigger ports were connected to each other with bnc cables. we had to move the cameras so far away that we captured what was happening at the confluence and a marker that we placed above the confluence so that the edge of the stand could not be seen in the photo. figure 3 shows a view of the placement of the cameras from the direction of the side stream and opposite the side stream. figure 3. view of the placement of the cameras from the direction of the side stream (left) and opposite the side stream (right) the original plan of experiment was to set up five speed cameras, with the help of which we could record the events at the confluence from several angles and produce a more accurate 3d model. in the end, we managed to get two speed cameras, which we placed on a stand made for this purpose. it was important that the cameras were at rest and that the vibrations at the confluence and on the testing facility did not affect the quality of the photograph. we placed the cameras above the side channel and thus directly recorded the events in the confluence from two angles. the camera was positioned so that in the center of the photo there was an event on the water surface of the confluence of two flows and a marker above them, so that we shifted them by 60 cm, on an imaginary circle the angular distance between them was 30°, as shown in figure 4. figure 4. placement of cameras at testing facility dss vol. 2, may 2021, pp.96-111 100 there were several influences on the camera placement positions. since we had a wave that was high, we had to position them so that we also caught the top of the wave so that we could measure the area. in addition to wanting to capture the top of the wave, we also had to capture the bottom, but we had to be careful not to pull the camera too far away from the confluence, as we would lose a lot of information about the topography. the position of the edges of the testing facility also influenced the position of the camera, as the edges made it impossible for us to capture some shots at the confluence. the angle of 30° was chosen because the reality capture software, in which we performed the bulk of the reconstruction of photos into 3d models, recommends an angle between 15° and 30° depending on how many cameras are being used. since we only used two cameras, we chose the largest possible angle to try to capture as much of the action as possible. if we chose a smaller angle, we would not get much more information than if we recorded with a single camera, but if we chose a larger angle, the program would not detect common points. 3.2. lenses we used two wide-angle lenses, as we wanted to capture the widest possible viewing angle. we used a lens with a focal length of 18 mm. as a result, we captured the glass edges of the measuring station, which we then cut off in the adobe photoshop software environment. the following lenses were used: af-s nikkor 18-200 mm 3.5-5.6 ged, af-s nikkor 18-55 mm 3.5-5.6 giied. 3.3. lightning due to the camera settings, which required a lot of light on the sensor, we installed nine different light sources. the events were exposed to the sensor for a very short time, as we took thousands of shots in one second. therefore, adequate lighting of the recorded object is crucial. in addition, we had to illuminate strongly so that we could set the aperture speed to a low value due to the better sharpness of the recorded events. the light sources were positioned so that all the light beams were directed as far as possible towards the center of the confluence of flows, as shown in figure 5. if the light were not directed evenly, one part of the testing facility or the confluence would be illuminated better than the second part, which would help to ensure that the edges of the confluence were not correctly detected when making the 3d model. figure 5. lightning at testing facility light sources were installed above the main and side channel, above the confluence, above the drain channel and five more halogen lamps, which were installed either directly on the l profile (three lamps) above the water surface or with a transverse profile across the channel (two lamps). four led lamps and five halogen lamps are installed, and the lamp on the diagram, marked with a cross in a circle, is an led lamp mounted directly above the confluence. main channel si de c ha nn el transverse profile above the channel dss vol. 2, may 2021, pp.96-111 101 3.4. experiment scenarios to perform the experiment, we set eight different scenarios. the scenarios differed from each other in the set flow on both channels and in the height of opening at inlets. we used three different channel opening heights and eight different flow settings, all in supercritical mode. to determine the froud number, we had to calculate the velocities and characteristic dimension for the experiment. the velocity was determined by the equation below. we have shown an example of calculating the froud number in the main channel for the first scenario, for the other scenarios in the main channel and in the side channel the procedure is identical. we first had to calculate the water velocity in the canal. 𝑣 , = 𝑄 , ̇ 𝑆 = 𝑄 ̇ 𝐻𝑑 = 0,0158 𝑚 𝑠 0,010𝑚 ∙ 0,500𝑚 = 3,167 𝑚 𝑠 (5) here 𝑄 , ̇ is the water flow in the main channel in , 𝐻 is the opening height and 𝑑 is the width of the main channel. we then determined the characteristic length 𝑙, which in our case is the height of the channel opening. using this data, we were able to calculate the freud number for the first scenario in the main channel. the procedure is shown in the equation below. 𝐹𝑟 , = 𝑣 , 𝑔𝑙 , = 3,167 𝑚 𝑠 9,81 𝑚 𝑠 ∙ 0,01𝑚 = 10,11 (6) all scenarios with calculated velocities and froud numbers are shown in table 1. table 1: scenarios for experiment opening height [𝒎𝒎] scenario flow in main channel (𝑸𝒎)̇ 𝒎𝟑 𝒉 flow in side channel (𝑸𝒔)̇ 𝒎𝟑 𝒉 velocity in main channel (𝒗𝒎) 𝒎 𝒔 velocity in side channel (𝒗𝒔) 𝒎 𝒔 froud number in main channel (𝑭𝒓𝒎) fround number in side channel (𝑭𝒓𝒔) 10 1 57 42 3,17 2,33 10,11 7,45 2 67 50 3,72 2,78 11,88 8,87 15 3 103 77 3,81 2,85 9,94 7,43 4 122 65 4,52 2,41 11,78 6,28 5 124 83 4,59 3,07 11,97 8,01 25 6 156 112 3,47 2,49 7,00 5,03 7 174 128 3,87 2,84 7,81 5,74 8 180 80 4,00 1,78 8,08 3,59 4. making of 3d model in this section, we describe the process of obtaining the results of our experiment. it describes how we processed the photos, made and processed the mesh, made a 3d model of the water surface at the confluence and finally measured the flow height. dss vol. 2, may 2021, pp.96-111 102 to create a 3d model, we used several different software tools, with which we finally came to the desired 3d model: photron fastcam viewer: we used this software to capture photos and transfer photos in bmp format to a computer. adobe photoshop: a software tool that allows us to convert photos to jpg format and process photos, as mentioned in chapter 4.1, which serves to change the color photo to black and white and automate this process for all photos in the series. reality capture: the central programming environment, with the help of which, as described in chapter 4.2, we created a 3d mesh in the format of obj from photographs and initially cut and processed the 3d mesh. meshlab: a software environment that reduces the number of mesh elements without much loss of topography information, as described in section 4.3. in the end, we got a 3d mesh in the form of a stl format. autodesk fusion 360: using this program, we created a 3d model in iges format from the 3d grid, as described in chapter 4.4. nx siemens: a modelling software who was then able to manipulate the 3d model, measure the height as described in section 4.5, and place it in a 3d sketch of the measuring line for easier representation. 4.1. processing photos before creating 3d mesh figure 6 shows two photos, recorded for scenario 2. one photo is in color and other one is in black and white. figure 6. black and white photo recorded with camera 1 (left) and color photo recorded with camera 2 (right) for further processing, we had to change the photo from .bmp to .jpg format using adobe photoshop software, as we could not process colored photo in the original format. using the batch feature in adobe photoshop, we did the same with all the photos automatically. using the same feature and program, we then converted the color photos to black and white. we then imported all the photos into the reality capture software, with the help of which we created the .obj model and exported the mesh for further making of the 3d model. we inserted 50 images from the first camera and 50 images from the second camera, which were taken in sync, into the program. we did this because the program does not allow you to create a model from only two photos, i.e. from one photo on camera 1 and from one photo on camera 2. when we imported photos, we selected the detect markers function in the reality capture software, so the program itself detected a marker to determine orientation in space. the marker was generated by the reality capture software itself using the generate markers feature, so we were able to print it and the program detected it immediately. the problem arose when the program detected only the marker from all the events on the testing facility, so that in reality it produced only a 3d representation of the marker, as shown in figure 7. due to the lack of common points on the water surface at dss vol. 2, may 2021, pp.96-111 103 the confluence with the common point on the marker, which software detected in all photos, software considered the marker to be the center of our events and thus predicted the need to create only a 3d model of the marker. figure 7. 3d model of marker therefore, we decided to remove the markers from the photo and crop the photos as much as possible in such a way that the largest share of the photo is happening at the confluence of flows. in order for reality capture to better recognize that we want to create a 3d model of the water surface, we have further brightened the water, which has also helped to better detect the edges. we did this in the adobe photoshop software, where we processed all the photos by lightening the flow and darkening the background as much as possible to best separate the edges of the water surface from the background. the differences between the photographs before processing and after processing are shown in figure 8. figure 8. photo before removing markers (left) and after removing markers and enlightening flow (right) 4.2. mesh creation based on the reasons presented above, it was decided to remove the markers from the image and undertake the 3d reconstruction only with photographs of the water. so we first cropped all the photos from both cameras to the same resolution, using adobe photoshop again, and using the batch feature, we automated this process for all the photos. the photos thus processed were then inserted into the reality capture program. immediately after importation, the program itself detected somewhere between 6,000 and 7,000 total points in the photos. since we already had enough common points in the photos, we chose the align images function in the reality capture software, which created a cloud of common points from the photos, as shown in figure 9. dss vol. 2, may 2021, pp.96-111 104 figure 9. cloud of common points on photos after creating a point cloud, we were able to start making a 3d mesh. we did this by selecting the normal detail function in the reality capture software environment, which means that we used medium-precision 3d mesh fabrication. we did not choose higher accuracy because this would greatly slow down the reconstruction process and make it impossible to produce a 3d model due to the large number of elements. so we got the first coarse3d mesh. using the texture function in the same software, we also added a texture to the grid to make it easier to process. the coarse mesh is shown in figure 10. figure 10. coarse mesh with texture we had to process the coarse mesh by trimming anything that didn’t represent water, such as the walls, the light reflections from the wall, and various very small droplets that weren’t part of the reconstruction. we first trimmed the model so that we only got water at the confluence, then with the help of the close holes function in the reality capture software we closed all the holes in the model that would hinder the production of the 3d model. the smoothing tool function, which is also part of the reality capture software, smoothed our surface a bit, thus achieving an even smaller number of elements. finally, we checked to see if we had any more bugs on the model, using the check topology feature in the same software environment. in the end, we got a trimmed mesh. dss vol. 2, may 2021, pp.96-111 105 4.3. processing the mesh the model was then exported in the form of obj. from the obj format, we wanted to convert the reconstructed object into a 3d model, which can be imported into the modeler and manipulated (we add other elements, measure the flow height, determine the topographic properties…). in order to do this, we had to reduce the number of elements. we had to do this so that by reducing the elements, the key topographic properties of the model are not lost, but that we still get below 10,000 elements. the network was processed using the meshlab program and the quadratic edge collapse decimation function. the original mesh had 18,189 elements. since the program (autodesk fusion 360) for converting a mesh to a 3d model is limited by a finite number of elements, which is a maximum of 10,000, we decided to reduce the number of elements twice, and in marked places where reducing the number of elements will not lose key topography information. the function of the meshlab software, called preserve topology, which enables the preservation of topographic properties despite the reduction in the number of elements, also helped us to preserve the topography of the model. it is important to reduce the number of elements so that not too much information is lost, as shown in figure 11. figure 11. mesh with less elements (left) and mesh with more elements (right) [6] in the end, we created a mesh with 9,094 elements and saved the mesh in .stl format, which allows the creation of a 3d model, but does not allow the preservation of the textural properties of the model contained in an .obj file. textures were no longer needed at this stage, as we only needed them in the initial process to be able to separate the water at the confluence from the other elements. figure 12 shows the difference between the mesh before processing in meshlab and the mesh after processing. we notice that the differences in topography are smaller despite the two reductions of the elements, and we can also notice that the mesh has no texture after processing. figure 12. mesh before element reduction (left) and after element and texture reduction (right) dss vol. 2, may 2021, pp.96-111 106 4.4. creation of 3d model we started creating a 3d model in autdesk fusion 360 software. after importing mesh into a software, we chose the mesh to brep function, which creates a 3d model from the mesh. once the program created a 3d model, we exported it in .iges format to obtain a 3d model, as shown in figure 13. figure 13. 3d model of confluence of two flows then, for easier presentation, we made a rough shape of the testing facility and placed the water surface model inside the created testing facility model in the nx siemens software, as shown in figure below. figure 14. 3d model of confluence in testing facility model we can see that the model has almost no depth, it is also very roughly trimmed, as shown in figure 15. it doesn’t have depth because we only captured with two high-speed cameras, so we captured a very small angle of action. since it is very difficult to determine the boundaries of the confluence from the surroundings due to the transparency of the water, we cut off a large part of the model, which apparently belonged to the water confluence. this makes it difficult to determine where the bottom of the model is or where the starting point for measuring height is. main channel side channel 3d model of confluence dss vol. 2, may 2021, pp.96-111 107 figure 15. 3d model of confluence from left (left) side and right side (right) 4.5. turbulent flow height measurement after importing the 3d model into the modeler, we were able to measure the wave height. we would have to scale the 3d model first, as we only got the shape, not the real dimensions. in order to be able to scale, we would need a reference height or some reference length measure in the photo in at least one scenario, but we did not perform this measurement, so the heights are given only in some scale, and for further measurements we would need a more accurate reference length measure which could scale our 3d model. an example of height measurement in the siemens nx software environment is shown in figure 16, shown below. figure 16. turbulent flow height measurement we managed to create models for seven of the eight scenarios performed. the height was measured at the highest point in the model, the unscaled results are shown in table 2, where parameters of all scenarios with measured turbulent flow heights were shown. dss vol. 2, may 2021, pp.96-111 108 table 2: parameters of all scenarios with measured turbulent flow heights opening height [𝒎𝒎] scenario flow in main channel (𝑸𝒎)̇ 𝒎𝟑 𝒉 flow in side channel (𝑸𝒔)̇ 𝒎𝟑 𝒉 velocity in main channel (𝒗𝒎) 𝒎 𝒔 velocity in side channel (𝒗𝒔) 𝒎 𝒔 froud number in main channel (𝑭𝒓𝒎) fround number in side channel (𝑭𝒓𝒔) wave height measurement (𝑯𝒘) [𝒎𝒎] 10 1 57 42 3,17 2,33 10,11 7,45 10,80 2 67 50 3,72 2,78 11,88 8,87 23,13 15 3 103 77 3,81 2,85 9,94 7,43 38,32 4 122 65 4,52 2,41 11,78 6,28 44,24 5 124 83 4,59 3,07 11,97 8,01 24,23 25 6 156 112 3,47 2,49 7,00 5,03 18,03 7 174 128 3,87 2,84 7,81 5,74 / 8 180 80 4,00 1,78 8,08 3,59 36,60 5. discussion at first glance, we can see that neither the shape nor the height of the flow correspond to the real situation, so we can conclude that the reconstruction failed. this can already be seen in figure 17, which shows a photo we took with a high-speed camera and a 3d model we made. the very rough shape is reconstructed correctly (in 2d shape) but when recording water there are many factors that affect the quality of the shot. figure 17. high speed camera photo (left) and 3d model (right) the first thing we notice is that the edges and shape are not precise. this happened because the software could not accurately separate the water from the environment around water. this happened because we directed so much light into one part of the confluence (into the part of the water where the dynamics were greatest) that the other part remained virtually unlit. thus, one part of the confluence is too illuminated, where losing the topographic properties of the current occurred, and the other part is poorly visible. to make the original, coarsest shape, we should direct the light as evenly as possible across the entire water flow. another problem associated with lighting is that light on water reflects differently at different angles. in other words, one drop or any other water part can be seen differently on photo from one camera than on photo from other camera, which means that making a 3d model was difficult because the program did not find some common droplets because it did not detect them as uniform in both photos due to different lighting. the solution would be a light source that is as evenly directed and scattered across the water surface. we also found that it is possible to increase the brightness of the water quite effectively with software processing, so that such lighting is not required, as it can be replaced in software photo processing. dss vol. 2, may 2021, pp.96-111 109 the third problem is that we didn’t capture the same frame with both cameras. this was made impossible for us by the configuration of the testing facility itself, as we were limited by the glass edge of the channel, which made it impossible for us to capture the frames located behind the wall of the channel. we were able to capture this shot with one camera, but not with another. an example of a photograph with both cameras is shown in figure 18, where we notice that a large part of the frame on camera 2 is missing. this could be corrected by changing the flows so that the action would take place in the middle of the channel, where the footage could be captured on both cameras. figure 18. frame shot on camera 1 (left) and camera 2 (right) the next problem was the marker. the marker is used so that the program can orientate from where the photos are taken, depending on how far the marker is moved to one or the other side. with the help of a marker, it then makes a reconstruction of the object located around the marker. because we placed the marker outside the center of events, the program practically made only a 3d model of the marker, and did not detect water at all. for better results and in general for the use of the marker, it would be sensible to place the marker in the center of events, preferably directly in the watercourse of the confluence so that the marker is visible in all photographs, as seen in figure below on right, where 3d reconstruction of cavitation structures was discussed. we can see that in this case the marker is placed so that it is located in the center of the event or movement of the ultrasound probe. it would also make sense to place a few objects in the confluence that would be visible on all cameras (a small marble that is attached to the confluence with a string, but does not affect flow conditions), differently colored segments of water or testing facility visible on all cameras, and it would also help to install more markers, but it is crucial that they are all visible in all photos. figure 19. placing a marker outside the center of events in our experiment (left) and placing a marker in the center of events in the experiment (right) [4] the biggest problem, however, is the number of cameras. since we used two cameras, we met only the minimum requirements for the number of cameras, so that it is theoretically possible to make a 3d model. the original purpose was to shoot with a high-speed camera, so that we could create more 3d models in a short time (less than half a second), and then create 3d models depending on the time change of the water level. we dss vol. 2, may 2021, pp.96-111 110 would need more speed cameras for this purpose. to make our model, however, we would only need as many cameras as possible and not speed cameras, which would be placed in as many places around the confluence as possible, thus capturing events from several angles. it would be important to have as similar a sensor as possible, so it would be ideal to shoot with the same cameras that have the same aperture speed and that are synchronized. for the purpose of capturing topographies at a given moment, it is not necessary to have fast cameras as slow cameras can be used, which are also cheaper. it would also be helpful if all the cameras were producing colored photos as this would give us more information. with two cameras recording a 30° angle of view, representing only 1/12 of the total 360 ° frame, we obtained very little data on the depth and topographic structure of the water surface. it is clear from the 3d model that we lack the depth that we would gain with a larger number of cameras or a larger viewing angle. given that the recommended distance of the cameras from the center of the event is 15-30°, it would be optimal to install between 12 and 24 cameras, depending on a certain angle of distance between the cameras. it would also be important to install at least one, and preferably five high-speed cameras above the confluence, with which the topography would also be recorded from above. the cameras above the confluence are not essential for determining the flow height, but they are important for making the 3d model as accurate as possible. it would also make sense to capture photographs from different distances from confluence, i.e. closer for a more accurate capture of topographic details or more remote for better edge detection of the 3d model. 6. conclusions in this article the subject of the method of measuring the height of a turbulent flow at the confluence of two flows with the photogrammetry method was considered. at the test site, the confluence was filmed with two high-speed cameras placed above the side-flow channel. the photographs were then processed accordingly, with the help of the reality capture software, a 3d reconstruction of the confluence was made and the wave height was measured. following was found out:  we found out that it is possible to make a 3d model of the confluence with the method.  it was found out that the method is not accurate if only two high-speed cameras are used, and that the key to the accuracy of the method is to use as many cameras as possible from as many confluence angles as possible.  we showed that the marker should be placed in the center of events for greater accuracy of 3d modeling.  we also found out that in order to measure the wave height at the confluence, it is necessary to have a reference length in the photograph, with help of which we can subsequently determine the exact wave height.  we proposed corrections when performing the experiment.  we also made suggestions for improving the reconstruction process. the obtained results provide an appropriate basis for the basic starting point of repeating the experiment with all the proposed corrections. these suggestions allow for good planning of both the execution of the experiment and the further processing of the obtained photographs all the way to the production of 3d models. we believe that the proposed corrections will enable a successful and accurate reconstruction of the confluence. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. dss vol. 2, may 2021, pp.96-111 111 references [1] f. steinman, hydraulics, university of ljubljana, faculty of civil engineering and geodesy, 2010. [2] g. rak, topological structure of water level at the confluence at torrential flow, phd thesys, university of ljubljana, faculty of civil engineering and geodesy, ljubljana, 2017. [3] p. novak, a. i. moffat, c. nalluri, hydraulic structures, taylor & francis, 2007. [4] g. kozmus, reconstruction of dynamics and topology of cavitation structures on an ultrasound probe, master thesys, university of ljubljana, faculty of mechanical engineering, ljubljana, 2019. [5] e. m. mikhail, j. s. bethel, j. c. mcglone, introduction to modern photogrammetry, john wiley & sons, new york, 2001. [6] free 3d, hair toon 3 quality mesh, availible at: https://free3d.com/3d-model/hair-toon-2-quality-mesh6253.html. microsoft word 84-93_244 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.84-93 https://doi.org/10.37868/dss.v4.id244 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 84 analysis of presidential regulations concerning cyber security to bolster defense policy management rizky ramadhianto1*, tahan samuel lumban toruan2, susaningtyas nefo handayani kertopati3, hikmat zakky almubaroq4 1,2,4 republic of indonesia defense university, defense management study program, indonesia 3 republic of indonesia defense university, asymmetric warfare study program, indonesia *corresponding author e-mail: rizkramdht@gmail.com received: aug. 8, 2023 revised: oct. 2, 2023 accepted : oct. 4, 2023 online: oct 9, 2023 abstract as a developing country, indonesia must effectively manage its national defense by implementing defense policies which can be interpreted as management activities that transform into defense policy management entities. the objective is to protect against various dangerous threats resulting from the dynamics of the current strategic environment, which continues to undergo rapid and significant changes. cyber threats pose a potentially dangerous threat that has a multidimensional impact. therefore, this article analyzes one of the indonesian government's efforts to deal with cyber threats, which is in the form of presidential regulation no. 47 of 2023. the research employs a qualitative descriptive approach in the field of literacy studies, drawing on reputable sources such as journals, books, and internet materials. it investigates the management measures and strategies implemented by indonesia to combat cyber threats in accordance with presidential regulations for cybersecurity. these findings elaborate on the implementation of presidential regulations that concentrate on cyber crisis management and national cyber security strategy as a suitable and praiseworthy response to the constantly evolving cyber threats. nonetheless, addressing several challenges requires strategic competencies in leadership to formulate cyber defense policies and strategies and carry them out optimally.. © the author 2023. published by arda. keywords: presidential regulations; defense policy management; cyber crisis; analysis; cyber security 1. introduction indonesia, as one of the world's largest countries, possesses abundant national resources, which can bolster or jeopardize the national defense system if not managed proficiently and with suitable strategies. to avert potential threats, it is crucial to implement effective and reliable defense management, which ensures optimal deployment of national forces. defense management is crucial for the development of defense policies that necessitate an appropriate and sustainable planning mechanism [1]. defense management refers to a country's ability to effectively and efficiently manage its resources to serve national defense interests in a strategic and comprehensive manner, in accordance with management principles. this encompasses both short and longterm strategies aimed at increasing efficiency and effectiveness. the management of national defense includes planning, organizing, coordinating, commanding, and dss vol. 4, 2023, pp.84-93 85 controlling activities at the strategic and policy levels, without subjective evaluations. defense management at the defense policy level involves managing defense development policies, defense empowerment policies, defense force deployment policies, defense regulatory policies, defense budget policies, and defense oversight policies [2]. as defense management falls under the purview of strategic management, the policy-making process involves developing pertinent defense policies and strategies that address the current and prospective strategic landscape. alterations or developments in the strategic environment, influenced by values held within a nation's territory, inevitably impact the country's national interests. therefore, maintaining national security and upholding sovereignty and integrity are key priorities for each country, as they adapt to their unique national interests. national interests stem from two primary factors they can be rationally demanded because of necessity or changed due to circumstances. thus, a country's national interests are critical in effectively countering threats evaluated through the dynamics of the strategic environment [3]. with reference to the development of the current strategic environment dynamics which continues to experience rapid and massive changes, as a country, indonesia at present and in the future will not be separated from challenges, threats, disturbances, and obstacles that are increasingly complex, where the current threat model it has a broad scope and is undergoing a fundamental evolution. if in the past, threats were primarily related to conflicts between nations or threats to national territorial integrity, today's threats are multidimensional in nature, affecting numerous sectors and sub-sectors. cyber warfare is a multidimensional threat due to its potential danger being equivalent to that of kinetic weapons. the cyberspace revolution must be factored into national security and resilience efforts [4]. based on data from the global cybersecurity outlook 2023 report by the world economic forum, cybercrime by both state and non-state actors is rapidly evolving to take advantage of changes in a target country's political, technological, and regulatory landscape. this is done through a complex scope creation mechanism that includes volume as a new type of attack, resulting in an acceleration of cyber threats that outpaces the ability to counteract them [5]. additionally, the european union agency for cybersecurity (2023) predicts that 2030 will mark the pinnacle of the growing cyber threats of today's age. this begins with bottlenecks in the supply chain and reliance on software, to campaigns spreading disinformation and digital surveillance that threatens privacy. furthermore, inadequate analysis and control, vulnerable infrastructure, advanced hybrid threats, and the misuse of artificial intelligence technologies all contribute to this issue [6]. figure 1. emerging cyber-security threats source: enisa (2023) [6] dss vol. 4, 2023, pp.84-93 86 on the other hand, according to the 2022 study conducted by the international institute for strategic studies (iiss), indonesia must move up to at least the second tier as it currently remains in the lowest third tier [7]. the 2022 national cyber security index positions indonesia at 47th, classified as being in the weak category, with a score of 38.96 out of 100 [8]. this rank places indonesia at the third lowest position within the g20 countries. figure 2. indonesia’s cyber security index source: e-governance academy foundation (2022) as a country aspiring to become the fourth largest global economic power, indonesia must invest in its cyber sector to enhance its cyber capabilities. currently, compared to other developing countries, the indonesian government prioritizes cyber surveillance for domestic security more than cyber security and the use of digital technologies. although there were institutional changes related to cyber within the armed forces in 2014, at that time no military cyber strategy or doctrine had been developed. however, the first formal strategy for civil-sector cyber security emerged in 2018 [7]. if it is not seriously anticipated through the strengthtening cyber policy by the government, then incidents caused by cyber-attacks like data leakage due to hacking can continue to recur in the governmental institutions in indonesia. cybersecurity policy encompasses all aspects of digital data exchange, including internet usage, data privacy, network usage, and cyber defense. as with any policy, cybersecurity policy must strike a balance between necessary regulations and social freedoms [9]. cybersecurity policies should prioritize addressing the legal gaps that emerge when cyber policies are overly concentrated on regulating individuals, in order to avoid any redundancy with existing regulations [10]. the government's capacity to respond to cyber threats is restricted and is likely to fail without collaboration with other parties involved in the process [11]. developing a national cybersecurity strategy involves coordination across governmental and non-governmental entities, as well as the public and private sectors. this collaboration is essential to meet the challenge effectively. an assessment of the effectiveness of a cyber defense strategy can be conducted by examining the initiatives taken by the governments of the united kingdom and the united states, two prominent western powers. the uk is implementing an adaptive and responsive approach by increasing investment in creating a futuristic cyber domain that involves all segments of the country [12]. additionally, the uk government recognizes the significance of actively addressing the cyber dependencies of adversaries to ensure security in cyberspace. dss vol. 4, 2023, pp.84-93 87 meanwhile, the transition of presidential administrations and political parties from the trump to biden era in the united states has presented challenges for cyber policies, which are often limited by established conceptual, political, and strategic commitments [13]. policymakers have approached each policy by interpreting cyber threats with a focus on improving efficiency and effectiveness, rather than implementing radically new strategic or policy approaches . based on the comparison between cyber defense strategies as exemplified, eventually this article will analyze one of the indonesian government's efforts to address cyber threats through regulations, specifically presidential regulation no. 47 of 2023 [14] on the cyber security. this regulation intends to bolster policy management in the realm of defense, particularly in cyber defense. in this manner, administrative institutions and stakeholders of the state can attain cyber power and competence, fostering trustworthy and preventing cyber threats for stable and secure cyber security, thus serving indonesia's national interests. the research in this article addresses the need to respond to the increasingly complex and crucial dynamics of cyber threats in regard to national security. as the first cyber regulation released by the indonesian government, this study aims to analyze the management framework and identify the strategies utilized by indonesia to ward off cyber threats and provide insight for future cyber regulations. considering the recent release of this presidential regulation, this article holds significant value as a reference for future cyber studies and a potential source for policy recommendations. unlike what has been done by armencheva (2015) examines the factors impacting cyber policies and strategies in european union (eu) countries, while niedermeier (2017) evaluates national cyber defense strategies in central-eastern europe. in this article, we analyze indonesia's national cyber policy framework, with a focus on crisis management and indicators of cybersecurity strategy. this article can provide valuable policy recommendations for the government and produce effective outcomes for stakeholders in the field of cyber defense, thereby strengthening indonesia's defense capabilities. the research outcomes can also serve as a reference for academics and defense practitioners to enhance their understanding of defense management discipline. 2. research method this study employs a qualitative approach with a descriptive analysis methodology. qualitative research investigates individuals' lives, histories, behaviors, and the functioning of organizations, social movements, or kinship relationships to uncover findings that cannot be attained through statistical procedures or quantitative methods [15]. the study employs qualitative and empirical methods to examine the scope of cyber security regulations set forth by the indonesian presidency, with the aim of enhancing the management of defense policy. data collection techniques in qualitative research include observation, interviews, document analysis, and audio-visual materials. document analysis is a method of collecting data in qualitative research that involves analyzing public documents, such as newspapers and official reports, or private materials, such as personal journals, electronic letters, and letters. meanwhile, audio-visual materials referenced in qualitative research for data collection take on the form of photographs, art objects, videos, or sounds [16]. the research process necessitates time and adaptability, resulting in the definition of the research impacting the research design and methodology, which must also be flexible. the researcher opted for a qualitative approach after thoroughly gathering data from numerous information sources, including academic journals, books, and credible online sources. 3. results and discussion tracing the history, it is evident that the cyber sector in indonesia lacks strong institutions, coordination, and legal foundations due to the absence of a national strategy. this is primarily a result of inadequate attention to dss vol. 4, 2023, pp.84-93 88 cyber policy in indonesia. initially, the indonesian government prioritized cyber affairs when it broadened the reach of cyber defense to encompass the concept of total defense [17]. this was subsequently accompanied by augmenting the number of personnel in the national police of the republic of indonesia's (polri) cyber-crime units from 40 to 100 [18]. also, the national crypto agency was renamed as the national cyber and crypto agency (bssn). after re-organizing, bssn implemented a new role and released a national cyber security strategy that prioritizes cyber resilience, ensuring the security of public services, enforcing cyber laws, promoting a culture of cyber security, and protecting cyber security in the digital economy [19]. the establishment of this national strategy aims to promote global trust and facilitate multi-stakeholder engagement in indonesia's cyberspace. additionally, the government focuses on countering domestic terrorism and online extremism in the cyberspace domain. in 2014, the ministry of defense issued guidelines for national cyber defense [20], outlining strategies to prevent cyber attacks that could pose a threat to national defense and high-priority assets, such as private closed networks, telecommunications and banking networks, data centers, online payment systems, and key government assets [21]. economic national security and domestic instability can be affected by the consequences of cyber threats to national defense. nonetheless, deficiencies remain in the discussion surrounding the concept of sustained cyber-enabled warfare and efforts towards cyber-offensive tactics, such as enhancing counter-attack capabilities for the purpose of deterrence. furthermore, the 2015 defense white paper positions cyber defense as one of the mainstays of the national defense posture, designating the cyber security function as a core national defense capability that intersects with all other instruments of national power. this integration is accompanied by efforts to modernize the country's cyber capabilities [22]. 3.1. national cyber security strategy the analysis of presidential regulations no. 47 of 2023 regarding cyber security follows the 'means, ways, ends' theory created by the u. s army war college. this connection is utilized to protect national interests [23]. based on this understanding, strategy can be defined as a method of linking potential contributions to achieve specific objectives through the selection of predetermined priorities that consider the greatest impact. furthermore, it entails the ability to anticipate future developments to effectively manage resources, facilities, and existing infrastructure while using established means. the government aims to achieve its objectives by defining the scope of cyberspace governance as a domain with the potential to cause sudden strategic impacts on national goals, as outlined in this regulation's 'ends' aspect. to ensure continuity of the governance system, risk management must also be prepared to anticipate worst-case scenarios. if the government aims to enhance national cybersecurity, it cannot solely concentrate on the internal factors within the country. the government must also take into account external factors that can assist in achieving national interests. therefore, the government's provisions outlined in this regulation, specifically the exploration of international cooperation between nations and participation in forums and conferences, will undoubtedly enhance the nation's cybersecurity capabilities and serve as a platform for showcasing cyber power to compete on a global level. the presidential regulation advocates for the expansion of the national cyber power by bolstering information infrastructure, considering the vulnerability of information to cyber threats. hence, reinforcing national cyber joints is essential in averting diverse cyber threats that have the potential to disrupt the national cyber order. the next regulation should assess indonesia's national cyber capability, capacity, and quality. national cryptography receives special attention in the regulation as one potential indicator for creating cyber security policies. the cyber regulation at hand focuses on strengthening capabilities through various prioritized measures. these measures include optimizing risk identification and analysis, implementing cyber security risk protection measures, enhancing collaboration between stakeholders, increasing the effectiveness of national dss vol. 4, 2023, pp.84-93 89 cyber security risk mitigation, promoting international cooperation in bilateral, regional, and multilateral forums to foster a safe, peaceful, and open cyberspace. additionally, efforts are taken to improve the preparation and implementation of cyber policies. overall, the regulation aims to support and enhance cyber security in a comprehensive and structured manner. furthermore, the focus is on technical programs, including cyber crisis contingency plans, emergency response implementation, human resource skills development and implementation, and coordinated and sustainable training programs aimed at increasing awareness of cyber security. these programs aim to strengthen the secure exchange of information and provide high access time. to ensure the uninterrupted implementation of programs stipulated in the regulations, the indonesian government is taking steps to mitigate potential issues in the cybersecurity sector. this includes the cultivation of laws, raising public awareness of legal matters, and integrated law enforcement measures. the next aspect to consider is the use of resources to support the implementation of methods in achieving national cybersecurity objectives. these resources comprise people, processes, and technology, forming an ecosystem of critical information infrastructure. in terms of human capital as cybersecurity talent, early childhood education is advisable for the nation's upcoming generation, beginning from elementary to higher education levels. direct indonesian cyber experts to engage in scientific research, development, and innovation in the realms of cryptography and technology, in order to bolster national cyber advancement. efforts to establish a national cybersecurity infrastructure will undoubtedly impact the strengthening of effective and efficient cybersecurity technology and incident response capabilities, as outlined in government regulations and policy directives prioritizing international cooperation in cyber security. considering the strategic environmental development, advancements in science and technology, and the five-year national development plan, this endeavor is deemed fitting to back a quantifiable action plan at a national level that outlines and enforces the main areas of concentration in the national cybersecurity strategy. the matter is crucial for decision-makers and cyber policy analysts to avert misguided attention, for it elevates values as the ultimate goals to be reached, while interests serve as intermediary objectives. consequently, resultant policies would not aid in achieving national values and could prove detrimental. assuming the indonesian scenario is to strengthen fundamental capabilities in responding to cyber warfare challenges, the necessary actions involve changes in the national cyber development paradigm, beginning with personnel and technology, and also incorporating doctrine. the responsibility of policymakers is crucial for implementing the development of cyber defense. by observing divergent perspectives, they can create greater cohesion in cyber security. 3.2. cyber crisis management the examination of managing cyber crises is grounded in the management functions theory, which encompasses planning, organizing, commanding, coordinating, and controlling. the planning function involves taking the first steps towards achieving a goal, enabling the determination of tactical steps to be taken in the future. the organizing function centers on directing and orienting the division of major tasks at work, with a focus on hierarchy. the commanding function involves directing talent according to the plan in order to achieve work goals in an effective and efficient manner. the coordinating function aligns activities of all units at different levels to achieve objectives. the controlling function serves as the final step in ensuring that the overall management function operates in accordance with goals, standards, and targets by monitoring activities [24]. in analyzing the indonesian government's handling of cyber crises, these management functions are used as a reference. during the planning stage, the indonesian government is encountering obstacles related to their human resources, particularly the cyber skills of their national cyber talents. this is a result of not meeting the minimum standards for cyber security education accreditation, insufficient national funding for cyber security capacity programs, and a lack of formal cyber security education programs, which is evidenced by ad hoc dss vol. 4, 2023, pp.84-93 90 transfer of knowledge from trained cyber security employees, often involving multiple professional instructors in the field [25]. this situation has prompted speculation that it will take a minimum of two decades or longer for the indonesian government to establish a self-sufficient cyber defense capability by supplying cyber experts in cyber crisis infrastructure. according to a presidential regulation, there exists a coordinating entity called electronic system operators (pse) responsible for managing cyber crises. the pse comprises of individuals, state administrators, and business entities, as well as members of the public who independently or collaboratively provide, manage, or use electronic systems for their own or third-party needs [14]. defense planning has two primary objectives: the first is to attack defense policy, and the second is to ensure flexibility in achieving these objectives. the planning process entails analyzing existing information and data, making predictions, and setting goals. the government aims to proactively handle cyber crisis conditions by implementing a presidential regulation related to cyber security. this involves creating a contingency plan for cyber crisis management, accompanied by a simulation plan using a training and role-play mechanism to prepare for potential scenarios. socialization of the public is a crucial aspect in the planning stage of cyber crisis management. it is important for individuals to understand a range of cyber threats and techniques needed to mitigate the impact of cyber crises. this process should begin with a community-wide strategy and extend to all levels of indonesian society. organizing involves introducing flexibility while maintaining structural rigidity by reorganizing work processes within an existing framework, rather than restructuring existing organizations. this may include allocating national resources. the cyber security regulations include the formation of a cyber crisis task force organized by the president to address critical issues in cyberspace. the implementation stages executed by the cyber crisis task force are essential to achieving the president's directive for increased structure and systemization. commanding involves taking responsibility for decision making and providing direction and guidance to achieve established goals. the function of cyber crisis management is emphasized to ensure efficiency and effectiveness in various techniques and objectives of cybersecurity. consequently, a commanding role is needed, which is generally carried out by the pse in terms of following up on early warning information. on the other hand, the president holds the highest authority in providing directives for the national cyber management policy mechanism. moreover, the president oversees the command flow that is divided into two parts: firstly, the determination of the cyber-crisis status based on the head of bssn's proposal, and secondly, the determination to end the cyber-crisis status, based on reports from the cyber-crisis task force. the analyzed regulations on cyber security by the president indicate that the coordinating function plays the most critical role in managing cyber crises. the analyzed regulations on cyber security by the president indicate that the coordinating function plays the most critical role in managing cyber crises. as the coordinating process governs several other processes, it is expected to have a significant impact on optimizing national cyber security development. nonetheless, the coordination process requires attention to other factors, notably the establishment of systematic communication between concerned organizations. organizational communication involves the exchange of messages within a self-contained network. the primary function of organizational communication is to coordinate by disseminating information, emotions, and sentiments [26]. pse serves as a critical actor in coordinating cyber crisis management efforts with other key components, including the bssn and state administration agencies. as such, pse plays a crucial role in optimizing coordination functions. recently, pse received an initial report indicating a cyber crisis warning resulting from an escalation of a cyber incident, which subsequently evolved into a full-blown cyber crisis. to respond to cyber incidents and prevent their negative impacts in stages, three levels of cyber incident response teams were formed: organizational, sectoral, and national. each team prioritizes integrated elements in all cyber crisis response activities. dss vol. 4, 2023, pp.84-93 91 cyber crisis management involves stakeholders coordinating to implement cyber crisis communication protocols and disseminate information to the public. the subsequent step entails carrying out cyber crisis recovery by using a mechanism to restore affected electronic systems and utilizing alternative resources. the objective is to reassess essential and supportive functions to achieve recovery goals, which will be evaluated by recovery time below the maximum limit established in the cyber crisis contingency plan. furthermore, the quantity of data retrieved based on the predetermined minimum amount of data, alongside the retrieval of essential functions and supporting functions meeting the minimum requirements, serves as an indicator of the recovery process's effectiveness. the cyber task force presented the president with a comprehensive report consisting of a thorough analysis of their methods in managing cyber crises and their various successful endeavors. they also included recommendations for future actions in handling cyber crises. this stage involves the bssn function in the post-cyber-crisis period, along with pse to calculate the estimated value of damages and losses resulting from the cyber crisis. additionally, they calculate the estimated recovery costs and evaluate the cyber crisis. calculating the cost of recovery involves replacing the value of damaged assets and estimating the costs needed to restore electronic systems to their pre-cyber crisis state, while also taking into account any economic losses resulting from temporarily damaged assets. controlling refers to the practice of regulating activities or programs to ensure they remain on track in achieving predetermined goals. the process involves synchronizing different activities to avoid conflicts, prioritizing time allocation, and enhancing communication. intervention is necessary during the management of activities and programs to ensure that the focus remains on the goals set within the policy. to achieve efficient and effective cyber crisis management, the controlling function should be strengthened, as current regulations emphasize evaluation activities. the aim of this operation is to manage the cyber crisis by evaluating the handling of cyber emergencies in alignment with the contingency plan. furthermore, the expected outcomes are new entities for future consideration in making decisions regarding cyber security policies. however, incompatibility or overlapping between agencies in carrying out their duties can cause hiccups and deviation from the intended direction and function of cyber crisis management. it is crucial to avoid such issues. 4. conclusions defense management plays a critical role in sustaining a nation and its state, particularly in the development of policies and strategies that can be executed in both peacetime and wartime scenarios. within the framework of defense policy, managerial actions are necessary as decisions concerning defense policies are made by various institutions involved in defense-related fields, including cyber defense. the establishment of presidential regulations no. 47 of 2023 concerning cyber security is a suitable response to the evolving cyber threats and necessary for maintaining cyber security stability. its aim to address defense policy support elements, such as national cyber security strategy and cyber crisis management, is commendable. however, various challenges must be addressed, beginning with the strength and preparedness of the national cyber-infrastructure required for implementation. this includes the capabilities of national cyber talent and the managerial mechanisms implemented by policy actors, as decision-making in formulating cyber security policies involves stakeholders across sectors. therefore, effective strategic leadership is necessary to scan and analyze the strategic impact of cyber threats, identify both potential and factual threats, and formulate cyber defense policies and strategies. additionally, it is crucial to efficiently and effectively implement the national cyber defense strategy through the execution of defense policy management operations. in the future, a study can explore the strategic leadership model's effectiveness in guiding the vision and mission of national cybersecurity regulations to achieve optimal results. dss vol. 4, 2023, pp.84-93 92 declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. acknowledgments many thanks are conveyed to colonel air force dr. ir. hikmat zakky almubaroq, s.pd., m.si., ciqar. as chief of the defense management study program, for his guidance and inspiration in the completion of this article. gratitude is also expressed to major general tni (ret.) dr. drs. t.s.l.toruan, m.m., dipl. ss., ciqar, and dr. susaningtyas nefo handayani kertopati, m.si. who acted as supervisors for the final coursework and this article. references [1] h. bucur-marcu, p. fluri, t. tagarev, defence management: an introduction, geneva centre for the democratic control of armed forces, 2009. 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[26] s. n. h. kertopati, communication in security intelligence performance, gramedia jakarta, 2013. microsoft word 1-9_255 (online) issn 2744-1741 defense and security studies original research vol. 5, no. 1, 2024, pp. 1-9 https://doi.org/10.37868/dss.v5.id255 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 1 enhancing awareness of cyber crime: a crucial element in confronting the challenges of hybrid warfare in indonesia ihsania karin azzani1*, susilo adi purwantoro2, hikmat zakky almubarok3 1,2,3 defense managment, defense university of the republic of indonesia *corresponding author e-mail: ihsania.broto@mp.idu.ac.id received: dec. 7, 2023. revised: jan. 5, 2024. accepted: jan. 6, 2024. online: jan. 13, 2024. abstract the cyber defense center, abbreviated as pushansiber, is an institution responsible for carrying out the duties and functions of the defense strategic installation agency. pushansiber has an important role in implementing governance, cooperation, operations, and ensuring cyber defense security. however, this year there has been an increase in problems related to cyber attacks, such as phishing, malware, ransomware, spam. these cyber attacks are included in the concept of hybrid warfare which is believed to be a form of conflict that involves the utilization of various elements, one of which is cyber attacks, military, political, economic, and information aspects. this causes conflict situations to be complicated and demands a comprehensive approach in terms of defense and handling, with digital literacy and cybersecurity awareness which has an important role in defense management, the need for awareness and training, simulation, and certification to strengthen cybercrime awareness in every organization. the success of other countries that have established specialized cybersecurity teams and invested in advanced technology can serve as an example for indonesia. for indonesia, the cooperation between national cyber and crypto agency (bssn) and the ministry of defense in strengthening cybersecurity capabilities is an important step to safeguard infrastructure, protect sensitive data, and reduce potential disruptions from malicious cyber activities with the aim of strengthening cybersecurity capabilities. © the author 2024. published by arda. keywords: cyber crime awareness, cyber crime, digital literacy, hybrid war, cyber defense 1. introduction the phenomenon of hybrid warfare reflects a paradigm shift in the conduct of international conflict, that previously the main attention was focused on conventional military combat alone, however, over time with the advancement of increasingly sophisticated technology, especially in the field of cyber and information, the structure of conflict has undergone substantial changes that hybrid warfare involves a variety of activities, comprehensive and highly diverse military resources, programs, and application [1] all of which are carefully designed to achieve the maximization of persuasive political and economic influence without involving violence, with the goal being to reform a hostile government or group and simultaneously reverse political, dss vol. 5, no. 1, 2024, pp. 1-9 2 social, and economic instability [2] hybrid warfare also involves more than direct military action, but also includes elements such as propaganda, cyberattacks, and attempts to manipulate public opinion, from diversity to the purpose of making the political dimension more complex, especially since the parties involved can use digital platforms and social media to influence perceptions globally [3]. cybersecurity is currently the main focus for all countries in the world since information and communication technology began to be applied in various aspects of our lives today[ 4] in the use of technology in the era of rapidly growing digitalization, that the use of technology involves various fields, in terms of advances in information technology bring a positive impact on the ease of human life, but also bring potential that can endanger humans [5] regarding the use of technology in the era of increasingly rapid digitalization, the use of technology involves various fields, in terms of advances in information technology it has a positive impact on the ease of human life, but also carries the potential to be detrimental to humans. the influence of globalization and technological advances that enter the state and nation brings various impacts of change, from the influence of globalization now, it can be seen and cannot be denied anymore because the many technological advances that enter the state and nation involve various fields of legal certainty, social, economic, organizational, health, education, culture, government, security, defense, and so on along with the increase in the level of adoption of information technology and communication, risks and threats to misuse of this technology have also increased significantly, are high, and are increasingly complex [6] now, it can be seen and cannot be denied because of the many technological advances that have entered the state and nation involving various fields of legal certainty, social, economic, organizational, health, education, culture, government, security, defense, and so on. along with increasing levels of adoption of information and communication technology, the risks and threats of misuse of this technology have also increased significantly, are high, and increasingly complex. the author conveys in this article that it is felt that there is a need for better attention to policy and awareness as well as expanding ideas related to awareness for individuals and for ministries/institutions in dealing with cyber crime, especially in the context of hybrid warfare which is actually happening in indonesia at the moment, and could even become a war trend in the future writer too provide recommendations for overcoming the challenges posed by cybercrime for the two organizations in the ministry/institution, both bainstrahan, ministry of defense and bssn. this can be discussed in research in this field. this paper was written to address the specific need for increased awareness and understanding of the scope and methods of cybercrime, particularly in the context of hybrid warfare in indonesia, this is important for individuals, households and organizations because cybercrime is a significant and growing threat and has the potential to cause major losses and even business closures. the uniqueness of this paper lies in its focus on the unique challenges of cybercrime in the context of hybrid warfare in indonesia and provides a specific analysis of the impact of cybercrime in this context. the added value of this paper lies in the detailed analysis of the impact and challenges of cybercrime in the context of hybrid warfare in indonesia, as well as the practical recommendations offered to overcome these challenges. the author's contribution is to analyze the impact and challenges of cyber crime in indonesia, especially in the defense context, as well as valuable recommendations provided to mitigate challenges including increasing awareness about cyber security, providing training programs and educational tools regarding cyber security challenges and the consequences of information crime, and increase knowledge about the risk of loss of sensitive information. 1.1 definition and characteristics of „hybrid war“ hybrid warfare is a military strategy that combines conventional and unconventional tactics [1] to achieve strategic objectives through a combination of military, economic, diplomatic, and informational actions, dss vol. 5, no. 1, 2024, pp. 1-9 3 involving regular military force, cyberattacks, propaganda, and economic pressure, with the goal being to exploit the opponent's weaknesses and create confusion, difficult for states to target in an effective response, complex and dynamic, increasingly prominent in global security due to technological advances and geopolitical changes [7] from the increasing prevalence of hybrid warfare, to achieve political objectives, then, emphasizing the importance of cybercrime awareness in national defense is essential. hybrid warfare often includes cyber terrorism and cyber warfare [8] so it is important for states to be ready to address the threats, the use of the internet in cyberspace to execute or control hybrid threats has become a common tactic, and its role in hybrid threat scenarios is huge. states, therefore, need to devise strategies to counter cybercrime and raise awareness of the threat posed by hybrid warfare itself. this requires a comprehensive approach, including enhanced civilian and military readiness [9], innovative resilience and response strategies, and the development of new policies and doctrines hence states need to foster situational awareness of multidimensional joint campaigns for the long term and use active sensing to engage the perception of entities in the environment, understand their meaning, and project their status in the near future on the urban environment to mitigate subversive action [10], one of the measures by which states can increase their capacity to face the challenges of hybrid warfare and protect their critical infrastructure and institutions from cyberattacks and other hybrid threats 1.2 cybercrime as critical component the term "cybercrime" is used widely by governments, businesses, and the general public to refer to a variety of criminal activities and dangerous behavior involving the use of computers, the internet, or other forms of information and communications technology [11]. it is a growing social phenomenon in the information age. cyberspace has raised concerns globally due to its potential for significant damage and far-reaching effects, to avoid potential threats, the implementation of effective and reliable defense management is important, which ensures the optimality of the national defense system [12]. indonesia's universal national defense system (sishanta) [13] aims to maintain and protect sovereignty, maintain territorial integrity, and ensure the safety of the entire nation from various challenges and threats [14]. in the direction of this universal defense system includes the use of various national resources, natural resources and human resources, on this basic principle the benchmark that national defense is all efforts made to defend sovereignty, territorial integrity, and ensure the safety of the nation from various threats and disturbances that can threaten the integrity of the nation and state, including in the form of certain issues [15]. figure 1. annual report bssn 2022 of global security index (gci's last assessment was in 2020, the latest assessment update will be released in 2023 dss vol. 5, no. 1, 2024, pp. 1-9 4 defense management has a very significant role in the formation of defense policy, requiring accurate and sustainable planning mechanisms [2] and refers to a country's capacity to manage its resources effectively and efficiently to meet national defense interests in a strategic and holistic manner, in accordance with applicable management principles, this includes short and long term strategic planning aimed at improving overall performance [3]. based on the annual report containing cyber threat projections for 2023, indonesia's national cyber and encryption agency (bssn) is placed in 24th place with a score of 94.88 in the global security index (gci), based on the document confirms that its function is not only limited to providing an overview of the national cybersecurity situation in 2022 and cyber threat trends in 2023, but also acts as a form of accountability to the public for bssn's performance. it has been stated in the presidential regulation of the republic of indonesia number 47 of 2023 on national cyber security strategy and cyber crisis management the importance of realizing that technological advances can trigger cyber attacks that have the potential to cause social and economic losses, and threats to state sovereignty. it is emphasized that the need to develop a cyber security strategy and cyber crisis management at the national level including the development of a cyber security culture and the implementation of emergency response handling is part of the government's responsibility to protect the public interest from various forms of disturbance caused by misuse of electronic information and electronic transactions; it is necessary for steps to be taken seriously to maintain national integrity and security in the current new digital era. when viewed from the scope of cyber threat ranking in indonesia can be a very complex problem[16] in the future if not anticipated early, then the country's defense strategy plays a very important role in the sense of maintaining sovereignty, integrity, and safety from threats both traditional and non-traditional which are massively integrated that the essence of national defense is all universal defense actions, organized based on awareness of the rights and obligations of citizens, as well as belief in strength from within, the administration of national defense is carried out by the government and prepared with the state defense system anticipatory or can recognize risks and all forms of uncertainty [17] plays a very important role in terms of maintaining sovereignty, integrity, and safety from threats both traditional and non-traditional in nature figure 2. screenshot of ministry of defense data stolen by hackers and sold on stealthmole dss vol. 5, no. 1, 2024, pp. 1-9 5 in october, there was a serious incident threatening indonesia's national security, in which classified data in a ministry of defense work unit was leaked and can be accessed through stealthmole web [4] a hacker with special skills managed to gain access without permission. the hacker then marketed his services on the black market via twitter (x), with the intention of selling access to confidential documents and administrative rights on the website, backed up with various evidence of misconduct. in an attempt to prove access, the hacker shared screenshots and stated that the server stored about 1.64 tb of data, from screenshots showing the possibility of hackers successfully hacking the ministry of defense website including personnel management information kemhan web backup components, electronic procurement services and digital scripting. analysis from the ministry of defense suspected the presence of stealer malware on the personal computer (pc) of the document administrator, this loss of data can provide significant benefits to irresponsible parties, result in harm to indonesia's national interests, and potentially worsen the state of national security while increasing the risk of cybercrime. this study seeks to explore the effectiveness of world crime awareness prevention management techniques in responding to increasingly complex cyber threat dynamics, the aim of this study is to increase public and stakeholder awareness of cyber threats, with the hope of reducing cybercrime incidents. therefore, it is necessary to implement a national defense system [18] every institution or organization that has the capacity to respond anticipatively to these threats, and can raise awareness to staff and personnel about cybersecurity risks and increase cybercrime awareness in human resources as well as to prevent data leaks and address cybersecurity threats and build cooperation with other parties to strengthen efforts to prevent and handle cybercrime[19] this complex and multidimensional threat is significantly influenced by changes in the strategic environment and has a major impact on national defense capabilities. this article can provide valuable policy recommendations for the government and produce effective results for stakeholders in the field of cyber defense, the results of the research can also be a guide for myself, academics and defense practitioners to improve their understanding of the discipline of defense management. so as to strengthen indonesia's defense capability on national cyber security strategy and cyber crisis management to protect the whole nation and national interests. 2. research method this research applies descriptive qualitative research methods, which aim to explain the phenomena that occur in the field through direct observation or observation [18] as well as secondary data collection through literature study, documentation, and interpretation. data collection through literature study in this research includes document collection, including journals, books, articles, and news contained in newspapers and magazines [19] the data analysis process consists of data collection, data reduction (data condensation), data presentation (data display), and conclusion drawing/verifying [20]. 3. results and discussion 3.1 increased cyber threat awareness digital awareness is very important in preventing cybercrime, in this digital era, internet users must strengthen digital literacy to avoid cybercrime, that this shows the importance of digital awareness in dealing with threats in cyberspace, increased internet usage has led to a significant increase in cybercrime, so knowledge and learning about cybersecurity awareness is very important. understandingome both from outsiders, such as web phishing due to clicking on links carelessly, as well as from within (insiders) [21], we can explore where very worrying condition occurs if the perpetrator of cybercrime is also an expert in anti-cybercrime actions as well, so that the new mode of cybercrime is difficult to detect and solve with cybersecurity [22]. the dss vol. 5, no. 1, 2024, pp. 1-9 6 escalating frequency of cybercrime attacks poses a pressing issue, demanding swift resolution and immediate implementation of robust cybersecurity measures. addressing this challenge entails a proactive approach, including the enhancement of digital awareness through training programs, simulations demonstrating the causes and effects of cybercrime, and certification processes to elevate human resource competency in the realm of cyber defense [2] addition, caution and understanding are also required when using apps and digital payments. by improving and strengthening digital literacy at all levels of society and in all organizations, internet users will more easily avoid cybercrime and protect their personal data from misuse [22] and have taken proactive measures to protect their digital assets. some countries have even established dedicated cybersecurity teams and invested resources in advanced technologies to mitigate the risks associated with cyberattacks. from the various considerations of the evolving threat, indonesia needs to quickly realize the significance of cybersecurity and take immediate action to strengthen its defenses. among them, through cooperation in strengthening cybersecurity capabilities, indonesia can safeguard critical infrastructure, protect sensitive data, and reduce potential disruptions that may be caused by malicious cyber activities realizing the increasing prevalence of cybercrime in indonesia, and the many interrelated risks, the need to raise cyber security awareness is a must for individuals and organizations. this requires education of employees and the general public regarding various threats in the digital world, as well as responsible and responsive actions to mitigate these risks [23]. it can be seen how gaining knowledge about current security threats, including implementing best practices, and understanding the potential dangers of activities such as clicking on malicious links or downloading infected attachments will empower individuals to contribute to a safer digital environment both mandatory in an organization then awareness cyber security not only plays a role in financial security but also functions to protect sensitive information, thereby reducing the possibility of becoming a victim of cyber threats [24] for organizations, the need to implement a comprehensive security awareness training program is essential. encouraging a culture of vigilance within the organizational structure further strengthens the security posture, providing protection against the potential adverse impacts of cybercrime. 3.2 educational programs and skill development educational nitiatives and skill development [25] in the field of cyber security awareness in an organization play an important and very useful role in safeguarding sensitive information and mitigating the risk of falling victim to cyber threats, this includes recognizing cyber threats, understanding the associated risks, and implementing safe practices. if the individual employee does not pass certification in global crime awareness, then the use of rewards and punishments in cybersecurity awareness training can have varying impacts on individual behavior and the overall security culture within an organization. the main goal is to instill a culture of security awareness in the organization [26], enforce regulations to prevent errors if something goes wrong and equip all employees with the knowledge and tools to defend against cyber attacks. cybersecurity awareness training typically covers a variety of topics, including recognizing phishing attacks, emphasizing password security, addressing physical security issues, and ensuring the security of mobile devices/computers used is safe from malware. the importance of cyber security awareness arises from the enormous growth of cybercrime, where cyber attacks pose financial risks and disruption to businesses and individuals, recognizing the human factor as a significant vulnerability, businesses must address potential employee errors and knowledge gaps that can expose organizations to cyber threats, regularly promoting a culture of conversation and awareness through dss vol. 5, no. 1, 2024, pp. 1-9 7 end-user security awareness training ensures that employees stay informed about the steps necessary to secure personal and business information [27]. in short, educational programs and skills development in cyber security awareness are necessary for both individuals and organizations, serving to protect sensitive information and reduce the likelihood of succumbing to cyber threats. implementing a comprehensive security awareness training program, coupled with cultivating a vigilant organizational culture, contributes to improving security posture and reducing the risk of falling victim to cyber threats. 4. conclusions the conclusion that can be drawn reminds us that increasing cyber security awareness will play an important role in implementing national defense strategy policies as stipulated in minister of national defense regulation number 14 of 2023 if it is implemented effectively from cyber crime awareness starting with educational programs and skill development so as to provide benefits for individuals and the indonesian state and its stakeholders. those well-versed in cyber risks are more likely to comply with security policies, thereby minimizing potential security vulnerabilities and promptly reporting suspicious activity within an organization. in the field of hybrid warfare, digital awareness is becoming increasingly important, especially in combating the wave of cybercrime that accompanies the surge in internet use, a concrete form of overcoming these complex cyber attacks is the need to increase digital literacy and increase awareness of cyber security is very important for individuals and countries, because this can serve as a shield against threats in the vast cyber world. the diverse nature of cyber threats, both external and internal, adds to the complexity of detection and mitigation efforts. addressing cybersecurity challenges requires immediate attention from institutions and organizations. given the increasing frequency of cyberattacks, the authors advocate increasing digital awareness through initiatives such as training, simulations, and certification. this approach aims to increase human resource competency in cyber defense, which ultimately strengthens digital literacy at various levels of society and organizational structures. such measures can enable more effective use of the internet, reduce the risk of cybercrime and protect personal data. if seen from neighboring countries (singapore) that they involve the formation of special cyber security teams and large investments in advanced technology. this success model states the importance of strategic steps for indonesia. strengthening cybersecurity capabilities through collaborative efforts is critical to safeguarding critical infrastructure, protecting sensitive data, and mitigating potential disruptions stemming from malicious cyber activity. recognizing the importance of cyber security, indonesia must proactively take steps to strengthen its defenses against ever-growing cyber threats. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. acknowledgements many thanks are extended to col. tni au dr. ir. hikmat zakky almubaroq, s.pd., m.si., ciqar . as head of the defense management study program, for his guidance and inspiration in the completion of this article. dss vol. 5, no. 1, 2024, pp. 1-9 8 gratitude is also extended to dr.ir. susilo adi purwantoro, s.e., m.eng.sc., ciqnr., ciqar., ipu., cipa., asean eng, mayor jenderal tni, mayjen tni (purn) dr. agung risdhianto, m.d.a, brigjen tni (purn) makmur supriyatno, b.sc., s.pd., m. pd, 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[27] a. alyami, d. sammon, k. neville, and c. mahony, "the critical success factors for security education, training and awareness (seta) program effectiveness: a lifecycle model," information technology and people, vol. 36, no. 8, pp. 94-125, 2023, doi: 10.1108/itp-07-2022-0515. microsoft word 65-74_241 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.65-74 https://doi.org/10.37868/dss.v4.id241 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 65 yesterday, today, tomorrow; environmental refugees ibrahim yenigun 1, vildan balci 2*, abdullah yenigun 3, sinan uyanik 4 1 department of architecture, harran university, turkey 2*,3 environmental engineering department, harran university, turkey 4 department of environmental engineering, bursa technical university, turkey *corresponding author e-mail: vildanbalci90@gmail.com received: jul. 15, 2023 revised: aug. 5, 2023 accepted: aug. 8, 2023 online: aug. 12, 2023 abstract migrations, which are as old as the history of mankind, have taken place for many reasons and have increased with the addition of new ones. although wars and economic concerns are among the main causes, environmental problems have been one of the reasons that should be accepted in today's world. environmental problems that threaten the lives of all living beings, especially human beings, pose numerous risks. moreover, these risks have reached unlimited and global dimensions. one of these risks is the forced migration of people due to various environmental problems, especially climate change. those who have experienced this migration are defined as "environmental refugees", and they occupy an important place in recent literature. while many of the problems associated with the millions of migrants are still unresolved today, the fact that environmental refugees are being added with increasing momentum clearly demonstrates the importance of including this issue in research agendas. it is also a fact that migration poses serious problems not only for the migrants who are its subjects but also for the countries of emigration. the importance of the subject from both sides and the fact that it is pregnant with many problems, which can be seen with the domino effect, made it necessary to study the subject in detail. based on these considerations, in the study; the history of environmental refugees, its causes, problems, environmental refugees mobility in recent years, possible future scenarios, and social-economic dimensions are discussed, as well as evaluation and solutions are given. © the author 2023. published by arda. keywords: environment; refugee; migration; risk 1. introduction migration is a phenomenon that has caused almost every society to leave the regions in which they live, either voluntarily or compulsorily, for various reasons, since the existence of mankind. although wars, internal conflicts and economic concerns are among the most important possible causes of migration today, "environmental problems", which have increased in recent years, have taken their place among the most important triggering factors that influence the course of migration and make life difficult [1,2]. the negative dss vol. 4, 2023, pp.65-74 66 consequences of climate change, which is one of the most important environmental problems that transcends borders and whose main determinant is "human", has increased the migratory events of recent centuries by influencing the emergence of many new problems. societies that are particularly affected by this problem are underdeveloped or developing countries, where economic concerns are growing and risks such as drought, unproductive agricultural land and natural disasters are common. in this context, possible risks in disadvantaged countries, where environmental problems are rapidly accelerating, have forced people to migrate in search of a safer life [3]. in this context, societies that are forced to relocate due to environmental problems of global proportions are referred to in recent literature as "environmental refugees". unfortunately, there is no international legal agreement that recognizes the rights of these people whose natural livelihoods are threatened with extinction and whose only option is to migrate. for the future of the countries on the same ship, it is becoming increasingly important to evaluate and resolve the issue of environmental refugees, which is the focus of conceptual discussions, in all its economic, social and human aspects. because the risks of immigration, which is seen as a last resort, not only cause problems for the immigrants, but also bring problems in many areas such as economic, social, political, educational, health and security to the countries of immigration. in this context, in the study; the history of environmental refugee, its causes, the problems it brings, the mobility experienced in environmental refugees in recent years, possible scenarios that may arise from environmental refugees in the future are discussed, and it aims to draw attention to the importance of the issue by referring to evaluation and solution proposals. 1.1. environmental refugee history environmental problems, which have been increasing in recent years and have gradually turned into a global crisis, have deeply affected the way of life of societies, causing irreparable consequences and bringing the concept of "environmental refugees" on the agenda. although it is included in the literature as a term that has recently gained popularity, it is actually a phenomenon that has been expressed since the beginning of the 1980s [4,5]. this concept, first expressed by lester brown in 1976, was later put on the international agenda by el hinnawi in the 1985 report of the united nations environment program (unep) [6]. the predictions and results expressed in various reports prepared in different national and international platforms over time have been effective in increasing the interest in the concept of environmental refugees. however, despite the increase in the quality and quantity of studies carried out, the point reached is not considered sufficient to solve a series of problems caused by environmental refugees and expected to reach global dimensions. the fact that there is not yet a common agreement on this concept, which is expressed in particular as environmental refugees, has played an active role in increasing the problems. the basis of the reasons leading to this situation is the definition of a refugee in the geneva convention signed in 1951. the conceptual debates on the inclusiveness of the terms used in the convention's definition of refugees lead to environmental refugees being ignored in terms of legal status. according to the definition in question, "a person who, owing to a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion, is outside the country of his or her nationality and is unable or unwilling to avail himself or herself of the protection of that country, or has no nationality, and, as a result of such events, is outside the country of his or her former residence and is unable or unwilling to return to it owing to such fear. " [7]. as can be seen from the definition, there is no concept that can describe people who are stateless due to difficult ecological conditions such as "environment, climate, nature". this situation results in "environmental refugees" not being able to benefit from their refugee rights, but also causes conceptual crises in international courts [8]. environmental risks caused by climate change, whose slow but dramatic effects are still being debated, continue to force societies to migrate over time. it is expected that climate change, which is considered one of the most important crisis issues of the last century and is on the main agenda of the debates being conducted in all fields with populist discourses, will further aggravate the problems in many economic, social and environmental dimensions. in this context, the fact that the damage to the environment caused by the human factor is becoming more and more visible every day, compared to the past, makes the situation very difficult. the fact that the fear and worrying consequences that have taken place at the dss vol. 4, 2023, pp.65-74 67 ecological level have accelerated since the first day of environmental degradation clearly reveals the importance of the issue [5]. in this context, disadvantaged societies such as africa, which have been the focus of mass migration from the past to the present due to environmental problems and difficult living conditions, are just one example of this situation [9]. the existence of environmental refugees in the past, and the fact that it is one of the main reasons for human mobility, makes it necessary to revisit the issue. ignorance of this situation by national and international authorities hinders efforts to raise awareness of future mass migrations. 1.2. reasons for environmental refugee it is predicted that "environmental refugees", which are one of the consequences of rapidly accelerating environmental problems and are expected to reach global dimensions, may become a large-scale problem that will concern the whole world in the near future. as it will bring a series of problems, it is becoming increasingly important to identify the causes of environmental refugees and take possible measures. however, although it is not easy to draw a clear framework for the causes in the place of humanity, which varies in this direction, basically two reasons can be mentioned, which are important triggering factors. the first is temporary or permanent migration due to natural disasters such as landslides, earthquakes, tsunamis, avalanches, and volcanic eruptions. the second is migration due to slow but long-lasting destruction caused by the "human factor" and the inability to meet even the minimum basic needs that can sustain living conditions due to ecological degradation [6]. macroand micro-level risks related to climate change, which have a global impact and are mostly due to anthropogenic causes, are among the most important reasons for increasing the number of environmental refugees [9]. in today's world, where the consequences of this situation are strongly felt, insecurity in the areas of water, food, health and shelter, which are among the basic needs of life, triggers the phenomenon of migration and drags humanity into existential depression [10]. in this context, as expressed in figure 1.2.1 below, it is inevitable for humanity, which is struggling to survive by nature, to leave its place as a way out. for example, famines caused by drought in societies living in africa, south america and the pacific; agricultural land rendered unproductive by the threat of extinction of island nations due to rising sea levels; floods caused by heavy rains; conflicts arising from fear of resource depletion; insecurity; etc. due to their exposure to risks in different dynamics, forced migrations are experienced. in this context, ecological injustice, which particularly affects disadvantaged countries, forces millions of people to migrate every year due to environmental factors [4,11]. figure 1.2.1. effects and consequences of environmental events [12] dss vol. 4, 2023, pp.65-74 68 assessing the phenomenon of environmental migration together with the push factors that support various migrations, such as economic insufficiencies, social problems, restrictions on access to basic needs, will allow inferences to be made about the causes of environmental refugees with more robust data. for example, the melting of glaciers due to global warming, which is one of the results of climate change, causes sea levels to rise. this situation can lead to many vital problems, especially in island countries, by causing loss of habitable land, increasing the salinity of the soil and making it unproductive, and causing lack of access to healthy drinking water. this problem, which causes a lack of resources, increases social, social and economic conflicts in island countries and paves the way for an increase in migration rates. as can be seen from the effects mentioned here, it is very difficult to determine the first reason that supports migration. however, it can be seen that the most important factor based on all the problems is environmental degradation, and all the causes support each other. in this context, if we look at the regions where migration due to environmental reasons is experienced, it is predicted that it will affect the poor, underdeveloped or developing countries more than the developed countries [13]. because in recent years there have been persecutions, internal conflicts, economic problems of access to food, unproductive agricultural lands, violence, and so on. if we look at the societies that have had to leave their countries because of these events, it is clear that there are justified predictions. according to the 2021 data of the global trends report published by the united nations high commissioner for refugees (unhcr), the countries that give the most refugees are syria, venezuela, afghanistan, south sudan and myanmar. 6.8 million people were displaced from syria, 4.6 million from venezuela, 2.7 million from afghanistan, 2.4 million from south sudan and 1.2 million from myanmar. given the location of these countries, it is possible to evaluate them as the countries where the consequences of environmental degradation are experienced the most. in this context, social and economic problems such as famine, poverty, internal conflicts, violence and persecution in the country become an effective driving factor in the forced displacement of people. for the majority of migrants in the region, the only option is to migrate to neighboring countries where they can meet their basic needs for work, education, health and food. according to the aforementioned report, the countries hosting these refugees are turkey (3.8 million), uganda (1.5 million), pakistan (1.5 million) and germany (1.3 million) [14]. it is seen that most of these countries that receive refugees are underdeveloped or developing countries that experience a lack of resources. the flow of immigrants to these regions increases the displacement within the country by causing various problems such as infrastructure, health, education, food and job opportunities. although it is difficult to enumerate the reasons for the new problems that arise with the snowball effect, the decrease or disappearance of natural resources, which make it difficult to access daily needs, are among the main reasons for environmental refugees. if the developed countries, which continue to implement their competitive ideologies for the sake of modernization at the expense of the destruction of natural resources, continue their actions, it is expected that massive migrations will occur as never before. in this context, it is very important that ethical principles replace the purely consumption-oriented understanding of the developed countries, which play a major role in the causes of environmental refugees. before possible environmental problems reach more terrible dimensions, it is essential to ensure the sustainability of radical decisions at the international level and to implement them. 1.3. problems brought by environmental refugee the degradation of the environment, which is worrying the world day by day and is reaching dimensions that threaten the livelihoods of societies, creates a driving force and causes migration. with these new migrations, it is inevitable that the demographic imbalances in the distribution of the world's population will cause many problems. the possible consequences of climate change, such as the loss of agricultural land in recent years, the rise in sea levels due to melting glaciers, floods, earthquakes and droughts that affect daily life, expose the world to the flow of refugees. environmental refugees, whose numbers are increasing every year and are expected to reach global proportions, cause various social, economic and security problems. if we mention the main problems of the social dimension, it can be said that the cultural ties between the peoples of the region dss vol. 4, 2023, pp.65-74 69 who had to migrate and their own countries are weakened or even broken [13]. this situation, on the other hand, triggers the problem of adaptation experienced as a result of the coming together of societies with different cultures, histories and habits, and may lead to various humanitarian risks, either directly or indirectly, both for the immigrant refugees and for the countries exposed to immigration. these social vulnerabilities, in turn, create political, security and economic problems [15,16]. this situation can lead to more problems, especially in resource-poor island countries. for example, lake chad, which is located between the countries of cameroon, nigeria and chad, has a very important place for the countries of the region. this situation, with its environmental and economic aspects, poses several challenges. one of these difficulties is the immigration from different places to the countries of the region due to the drought problem that causes humanitarian crises. it is inevitable that various risks and problems will rapidly worsen due to the increasing migrations in addition to the current resource scarcity in the region [17]. as mentioned in the example, the migration of countries that are disadvantaged in the distribution of resources can cause economic problems due to food shortages, internal conflicts, socio-cultural reasons, and hinder development goals in the long run [13]. today, with the rapid impacts of climate change, these and similar examples can be multiplied. the migration problem experienced as a result of ecological injustice can also cause people living in migratory areas to turn to cities. unplanned population growth in cities will cause many problems such as food, health, lack of housing, pollution, infrastructure, education, lack of public services, security problems. the impact of this situation will be particularly felt in densely populated coastal cities that are likely to be flooded due to sea level rise. in fact, one of the most important reasons for the avalanche of these problems, as mentioned above, is that the crises experienced by people who have had to leave their historical and cultural habitats because of environmental problems have not had a legal basis. in this context, in the event of a sudden possible wave of migration, the lack of an international legal agreement makes it difficult for underdeveloped or developing countries to protect the values of the current status quo and creates various problems. because refugees, who are not under legal protection, cause an increase in events such as terrorism, crime, theft in the sheltered states, causing development, tourism, economy, employment, etc. it will cause negativities that will hinder the growth of countries in these areas. as can be seen, the problems caused by environmental refugees who have no legal status in different areas are very closely related to the sustainable development goals of countries. in this framework, the steps to be taken and the measures to be taken depending on the international consensus are very important for the correct intervention [15,16]. especially in recent years, many problems have not been fully resolved against the flow of refugees whose effects have been seen concretely due to reasons such as wars and internal conflicts, while the increase in the number of refugees in the environment causes the problems to grow even more. in this context, it is very important to solve the current or future crises instead of covering them up in order to use the limited resources in the world properly [18]. 1.4. environmental refugee mobility in recent years environmental refugee mobility, which is one of the controversial issues of international law, has always maintained its existence as a dynamic process depending on the change and transformation of nature throughout history. the term "environmental refugee mobility" can be used as a concept to study the negative consequences of environmental impacts with its human dimension [13]. especially in today's world, it is predicted that mass environmental refugee mobility will increase due to increasing climate change as a result of anthropogenic environmental degradation. [4]. in this regard, it is inevitable for people who are struggling to survive and seeking a more comfortable life by nature to carry out migration within and outside the country [2]. in particular, the increase in the number of natural disasters is closely related to the environmental refugee movement with short and long-term migrations. it has been observed that the number of natural disasters, which are the cyclical consequences of environmental events on a global scale, has approximately doubled in the last 20 years. due to the negative consequences of nature exposed to human domination and exploitation, which is responsible for this ecologically bad course, it was stated in the records that there were 21.8 million dss vol. 4, 2023, pp.65-74 70 human mobility between 2008 and 2016, according to the estimates due to extreme weather events in the united nations report. in 2017, it was stated that 3.2 million people experienced internal migration in the first nine months of the year due to drought and natural disasters [19]. in south africa, one of the regions most affected by climate change, extreme drought due to insufficient rainfall is forcing people in the region to starve or migrate. in early 2021, the united nations high commissioner for refugees (unhcr) reported that 1 million somalis were displaced due to the region's worsening drought, and more than 7 million people were at risk of starvation due to the drought [20]. another example of human mobility due to the impacts of climate change is that more than 870,000 refugees fleeing persecution in myanmar and seeking refuge in bangladesh have been exposed to natural disasters such as cyclones and floods, which have increased in recent years. the statement also noted that the majority of countries exposed to the risks of climate change host large numbers of refugees [21]. as can be seen from the above-mentioned reports, the consequences of environmental problems, which are among the most important agenda items of the 21st century, are most evident in underdeveloped or developing countries [22]. these risks increase the fragility of these societies, which can provide minimal access to their livelihoods and drag people into an existential crisis. in this context, it has been observed that disadvantaged societies, which are highly vulnerable and have difficulties in adapting to ecological problems, are more likely to act [13]. the yearly increase of the said environmental refugee movement paves the way for unplanned and uncontrolled migrations and greater risks on a global scale. 1.5. possible future scenarios as a result of the anthropogenic effects of modernization and globalization at the expense of the destruction of the planet, environmental degradation, which has accelerated in recent years, is leading the earth to an irreversible end. it is predicted that the countries of the world that will feel its effects more intensely in the future will face mass migrations of millions of people as a result of environmental insecurity, especially from the regions where ecological injustice is experienced. as shown in the graph in figure 1.5.1 below, according to the united nations high commissioner for refugees (unhcr) global trends report, the number of people forcibly displaced due to persecution, conflict, violence, human rights violations or public order disturbances is increasing every year [23]. examining the reports, it was announced that the number of people forcibly displaced in 2021 reached 90 million, despite the kovid-19 epidemic that began in 2020. in 2022, as a result of the wars, the number of refugees is expected to reach 100 million. figure 1.5.1 numbers of forcibly displaced persons indicated in global trends reports by year (prepared using (unhcr) global trends report data.) according to the figures given, it is predicted that these numbers will increase in the coming years due to environmental problems. it is inevitable that the number of environmental refugees will reach millions, especially in the regions where ecological injustice is felt the most. it is undoubtedly the most human right of dss vol. 4, 2023, pp.65-74 71 people struggling to survive in countries where natural events such as droughts, rising sea levels due to melting glaciers, floods and tsunamis, which are among the effects of global warming, are the most human rights. for this reason, the reduction of emissions has a very important place in minimizing these effects of global warming in today's world, where the importance of environmental sustainability against possible mass migration is increasing day by day. if it continues at this rate of increase, it is predicted that the possible future scenario will reach up to +5 0c on a global scale. although this situation includes the possibility of a further rise in sea level of 178 cm, the greenhouse effect is expected to exceed 2 m by 2100 if the melting of glaciers is also taken into account. the increases experienced in this context show that each 1m rise means a sea level rise 100m further from the coast. if these frightening dimensions affect the world in the future, it is expected that countries close to the pacific and indian oceans, which are highly threatened, will be more affected by the situation. thus, one of the inevitable effects will be that there will be a serious movement of human population from these regions, causing the population of the country to be completely relocated [24]. there are various estimates and studies on this topic. for example, figure 1.5.2 presents the possible scenarios for 2050 for the regions of sub-saharan africa, south asia and latin america in terms of people displaced by climate change, which is one of the consequences of environmental degradation. figure 1.5.2. possible environmental migration scenarios in 2050 [19] under the worst-case scenarios, an average of 143 million people from these three regions are expected to become environmental refugees. among these countries, it is estimated that most migration will take place in sub-saharan africa, where the effects of drought will reach tragic proportions in the possible scenario [22]. the international organization for migration supports these scenarios, stating that the number of environmental refugees will reach at least 200 million by 2050 [9]. it is inevitable that the countries causing the increase in these numbers will be underdeveloped countries with high levels of poverty. in this framework, dss vol. 4, 2023, pp.65-74 72 demographic changes bring many risks in infrastructure, food, economic, social and social are among the possible effects [25]. the future scenarios presented in another report, on the other hand, state that in the next 40 years, as a result of environmental degradation, an unprecedented migratory mobility will take place, affecting about 1 billion people. these estimates support the above scenarios. this expected overpopulation once again highlights the importance of environmental sustainability [22]. in this context, one of the most important steps to be taken is to define, on an international basis, the status of environmental refugee mobility, which is seen as the only option, especially in societies that are most affected by the consequences of ecological degradation and do not have sufficient advantages. if this step is taken, it will be possible to minimize the possible problems and risks associated with the mobility of environmental refugees, which is a focus of global concern, by developing the necessary plans and strategies at the international level. the creation of living spaces for people living in island countries where the sea level is rising will not only prevent possible mass migrations, but also prevent the crisis caused by the problems that may arise [9]. 2. results it is obvious that the migrations against various natural events throughout history have gained momentum in recent years. in particular, human intervention in nature has not even allowed the ecological cycle to renew itself, causing the process to be dragged into a global chaos. the developed countries, which play a major role in the deterioration of the atmospheric equilibrium, are almost preparing the end of human history on the planet by accepting that the problems are only regional. however, as the researches carried out in the course of time have shown, the environmental problems are felt on a global scale, but they also bring with them various problems that make human life difficult. in this context, climate change, which is the most noticeable consequence of environmental degradation today, is expected to affect the whole world in the coming decades. the most important indicator of this situation is the number of "environmental refugees", whose numbers are rapidly reaching millions, who are forced to leave their homes as a result of the increase in environmental events such as drought, desertification, flooding, rising sea levels, and the threat of extinction of drinking water resources. due to environmental degradation, people living in existential crisis in their countries are forced to migrate in search of a healthier and more prosperous life. the fact that there is still no consensus on the legal concept of environmental refugees makes the struggle for survival of refugees who have to leave their homes even more difficult. while the problems are growing like an avalanche, the future habitable planet is being pushed to an irreversible threshold. because the lack of legal regulation and the lack of solutions and planning for the future of the planet also affect the emergence of various socio-economic risks for people who are forced to migrate as the only way out as a result of environmental destruction. both the lack of legal regulation and the fact that it contradicts the interests of states at the expense of nature, climate and the destruction of the planet make the solution of the problems even more difficult. in today's world, where ecological injustice is on the rise, the fact that the number of environmental refugees has reached millions in the past and present, and that it will reach the numbers indicated in possible scenarios of future demographic changes, shows that the problem has acquired a global rather than a national character. a proactive approach to solving these problems, the cost of which will be felt especially in poor countries, before they get worse, is a point that should be considered for the existence of a livable world in the future. in this context, it is essential to raise more awareness in order to minimize the environmental degradation caused by anthropogenic effects, which are the basis of the problems and cause ecological injustice, on an international scale. especially for the underdeveloped or developing countries that are exposed to the flow of refugees due to the current wars, it is important to take a separate measure against possible mass migrations that may occur due to environmental reasons. because in a possible new wave of migration, it will be difficult to meet the needs of these countries in areas such as infrastructure, food, water, shelter, education and health, and it will be inevitable that other problems will come to the fore. in particular, the fact that environmental refugees are permanently migrating to more livable countries due to the lack of possibility of losing their dss vol. 4, 2023, pp.65-74 73 homeland and future life increases the importance of the issue. another aspect of the problem is that this situation will lead to factors that will increase interstate tensions due to lack of resources as well as socioeconomic problems in the future. in this context, the support of the developed countries to the countries that receive the environmental refugees will contribute to the prevention of the tensions between the countries. it is very important that they take a more active approach to solving the problem, since the main responsibility for the environmental problems that are currently occurring is the responsibility of the developed countries, which are focused on consumption and growth. however, if we look at the methods used in practice in many developed countries today, we see that most of the expenditures that need to be made to solve the problems are spent on arming the borders or building high walls. this situation is worrying for the future world and is a clear indication that there is not enough awareness of the problem. 3. conclusions it is clear that the mobility of environmental refugees, which has short and long term effects and is a result of ecological degradation mostly due to anthropogenic causes, brings with it a series of problems closely related to immigrants and countries exposed to immigration. in this context, according to the international research reports included in the study, it is estimated that the number of people living in disadvantaged regions, where ecological injustice is experienced, will exceed the limits in the coming decades, according to possible future scenarios, in order to achieve a more reliable life. in this context, the fact that environmental refugees do not have a legally protected status and that the debates on this issue have not been concluded for a long time, it is expected that in the future we will be faced with greater humanitarian crises and the creation of multifaceted dangerous dynamics, and it is necessary to take urgent measures to solve the problem. declaration of competing interest the authors declare that they haven’t any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] a. mutlu, i̇. i̇rdem & b. üre , "ecological refugee", country politics management, vol 10, no 23, pp. 79118, 2015. 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[25] m. demirbilek, "environment, environmental refugees and environmental social work", international journal of social sciences and education research, vol 2, no 3, 2016, [online]. available: http://dergipark.gov.tr/ijsser microsoft word 74-83_272 (online) issn 2744-1741 defense and security studies original research vol. 5, no. 2, 2024, pp. 74-83 https://doi.org/10.37868/dss.v5.id272 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 74 formation of the tni cyber force: a strategic and policy analysis aris sarjito1* 1 faculty of defense management, republic of indonesia defense university, indonesia *corresponding author e-mail: arissarjito@gmail.com received: oct. 13, 2024 revised: nov. 13, 2024 accepted: nov. 15, 2024 online: nov. 20, 2024 abstract the increasing cyber threats in indonesia require strengthening the country's defense strategy. this study focuses on the formation of the indonesian national army (tni) cyber force as part of efforts to strengthen the country's cyber security in facing increasingly complex threats. the purpose of this study is to analyze the policy and strategy for the formation of the tni cyber force and evaluate the synergy between institutions, especially with the national cyber and crypto agency (bssn). this study uses a qualitative method with a secondary data analysis approach, including reports from fortinet, awanpintar.id, and national policy documents related to cybersecurity. the research findings show that the tni cyber force has a crucial role in protecting indonesia's critical infrastructure from the threat of botnets, ransomware, and other cyber-attacks. the synergy between the tni and bssn is key to building an effective cyber defense system. although there has been an increase in cyber readiness, this study found that challenges still exist, including in terms of human resources and the technology used. in conclusion, the formation of the tni cyber force is an important step in dealing with cyber threats, but there needs to be further strengthening in cross-sector coordination and adoption of the latest technology. © the author 2024. published by arda. keywords: bssn; cyber security; national defense; synergy between institutions; tni cyber force 1. introduction research on the formation of the indonesian national army (tni) cyber force is rooted in the growing global cyber security threats, which have become a primary focus in modern defense strategies. the rapid development of information and communication technology has created a new dimension in warfare—cyber warfare— requiring the military to adopt more responsive strategic measures. according to white [1], cyberattacks have increased in both volume and severity, prompting many countries, including indonesia, to integrate cyber defense into their military structures. at the international level, countries like the united states and russia have pioneered the establishment of specialized military units dedicated to cyber defense [2]. this has inspired indonesia to take similar steps with the formation of the tni cyber force, aimed at securing the nation's digital sovereignty from external threats. recent research by mahendra [3] suggests that indonesia is currently at a critical juncture in strengthening its cyber security policies through military structural reforms, particularly by integrating cyber defense strategies into national policies. indonesia has faced a significant rise in the number of cyberattacks in recent years. according to reports from fortinet [4] and awanpintar.id [5], cyberattacks in indonesia have been increasing in both quantity and complexity. local companies and critical infrastructure have been the main targets of various types of attacks, including ransomware, botnets, and vulnerability exploits. this data underscores the importance of proactive dss vol. 5, no. 2, 2024, pp. 74-83 75 measures and robust policies to strengthen indonesia's cyber defense systems. the following table 1 presents key data from these reports. table 1. cyberattack data in indonesia (2021-2024) [6,7,8,9] category 2021 2022 2023 2024 (h1) number of cyberattacks 320,000,000 347,172,666 500,000,000 2,499,486,085 dominant type of attack ransomware ransomware ransomware admin access takeover botnet duration (days) 7 10 83 83 botnet attacks 19,104,200 35,911,749 35,911,749 126% increase ransomware attacks decreased 13% decreased 13% decreased 13% detected viruses in indonesia js/agent.cy!tr (4.8%) msoffice cve_2018_0798 (2.5%) cyber security score (ncsi) 38.96 (rank 83) 63.64 (rank 49) the data above shows that the number of cyberattacks in indonesia surged drastically, from 320 million in 2021 to more than 2.4 billion in the first half of 2024 alone. the most dominant attacks in recent years have been ransomware, though its detection has decreased by 13% over the past five years. however, the more concerning type of attack in 2024 is the takeover of admin access, indicating an increase in hackers’ ability to control victims' systems. the rise in botnet duration from 7 days in 2021 to 83 days in 2023-2024 indicates that botnets are becoming more persistent and harder to detect. another important finding is the significant increase in malware variants and vulnerability exploits, especially viruses like js/agent.cy!tr and vulnerabilities in msoffice cve_2018_0798. indonesia's cyber security score also improved, from 38.96 in 2022 to 63.64 in 2023, demonstrating an enhancement in national cyber readiness. however, many challenges remain, particularly regarding the surge of attacks originating domestically, as found by awanpintar [5], with most attacks coming from the jakarta and depok areas. these findings highlight the urgency for both the government and private sectors to take proactive steps in protecting indonesia's digital infrastructure, given the increasing risks of more targeted and sophisticated attacks. the formation of the tni cyber force, as outlined by arianto & anggraini [10], is also a response to the rising domestic cyber security threats, with hacking incidents against critical infrastructure such as energy and transportation spiking sharply. this study shows that the cyber force will function not only as a protector of digital infrastructure but also as a diplomatic instrument in addressing escalating international cyber conflicts [11]. therefore, this research explores the strategies and policies behind the formation of the tni cyber force, as well as how the tni can position itself to address global cyber challenges. the focus of this study is to understand the policy dynamics implemented by indonesia's ministry of defense and the tni in developing cyber capacity and to analyze the relevance and effectiveness of the adopted cyber defense strategies. the empirical problem in this study concerns the implementation of strategies and policies in forming the tni cyber force in indonesia. although the tni has established a cyber unit, there is no comprehensive data on the operational effectiveness of the cyber force in addressing real cyber threats. hacking incidents targeting critical national infrastructure, such as the transportation system and energy sector in recent years, indicate that indonesia’s cyber defense efforts still have significant weaknesses [10]. additionally, challenges such as limited human resources with technical expertise in cybersecurity and lack of coordination between dss vol. 5, no. 2, 2024, pp. 74-83 76 institutions in responding to cyberattacks reveal a gap between the designed policies and actual implementation [12]. normatively, the issues arising from the formation of the tni cyber force not only touch on national security aspects but also relate to broader ethical and legal issues. the use of cyber forces within a military context raises questions about the boundaries of technology use in cyber warfare, particularly concerning human rights and digital sovereignty. the regulations and legal frameworks underpinning the tni cyber force must address these questions while balancing national security with individual freedoms in the digital realm. below are several national and international regulations that serve as the legal framework for the formation of the tni cyber force:  law no. 3 of 2002 on state defense [13] article 1, paragraph (1) defines state defense as efforts to maintain the sovereignty of the country, territorial integrity, and the safety of the nation from threats, including cyber threats. this law serves as the primary legal basis for the formation of the tni, including the development of the cyber force to protect indonesia's digital sovereignty. in the context of increasing cyber threats, the tni must expand its operational scope to cyberspace in accordance with its national defense mandate.  law no. 34 of 2004 on the indonesian national armed forces (tni) [14] article 7, paragraph (2) explains the tni’s main tasks in maintaining the integrity of the republic of indonesia, including through military operations other than war (mootw), which can encompass cyber defense. this law mandates the tni to engage in unconventional military operations, such as cyber warfare, to protect the nation's strategic assets in cyberspace.  presidential regulation no. 82 of 2022 on the national cyber and encryption agency (bssn) [15] articles 2 and 3 outline bssn’s authority in maintaining information and cyber security and its cooperation with other institutions, including the tni, to protect critical infrastructure. bssn is a key partner in the formation and operation of the tni cyber force, requiring close coordination between the two agencies to holistically address cyber threats.  the geneva conventions and additional protocols (1949 and 1977) [16] although the geneva conventions do not explicitly regulate cyber warfare, the principles regarding the protection of civilians and critical infrastructure during armed conflicts also apply in the context of cyber warfare. the tni cyber force must operate within an international legal framework that upholds civil protection rights, especially regarding cyberattacks that could impact civilian infrastructure such as power grids or communication systems.  tallinn manual on the international law applicable to cyber warfare (tallinn manual 2.0) [17] this manual explains the application of international law, including the laws of war, in the context of cyberattacks. the tallinn manual provides guidelines on how cyber operations can be conducted by states during conflict, including by military forces. the tni cyber force must ensure that its operations stay within the bounds of international law, particularly regarding acts of cyber aggression.  law no. 11 of 2008 on electronic information and transactions (ite law) [18] articles 29 through 31 regulate information security, prohibitions against illegal access, and electronic data protection. the tni cyber force must also comply with the ite law, especially concerning the use of cyber technology in a military context that may involve accessing sensitive or electronic data. in forming the tni cyber force, there must be alignment between national and international legal frameworks to ensure that all forms of cyber operations are conducted in accordance with applicable legal principles. while national defense remains a priority, transparency, accountability, and the protection of dss vol. 5, no. 2, 2024, pp. 74-83 77 human rights in the digital world must always be upheld. these regulations form the foundation for determining the operational boundaries of the tni cyber force and ensuring that its military activities do not violate international legal principles or civil rights in cyberspace. 2. research method to ensure reproducibility, this research on "the formation of the tni cyber force: a strategic and policy analysis" adopts a qualitative research method using secondary data, following the approach outlined by creswell [19]. specifically, content analysis was employed, as described by krippendorff [20], to systematically analyze the selected data sources, focusing on policy documents, cybersecurity reports, and relevant regulations, including the defense law, the tni law, and global cybersecurity threat reports from fortinet [4] and the national cyber and encryption agency (bssn). content analysis was conducted to identify key themes related to cybersecurity strategies, such as the effectiveness of collaboration between the tni and bssn and the challenges encountered in implementing cyber defense policies. the analysis followed a structured coding process based on pre-defined categories that align with cybersecurity policy and strategy evaluation frameworks. the use of secondary data is central to this study due to the availability of comprehensive policy documents, legal regulations, and national and international cybersecurity reports. key sources include the fortinet [4] global threat report, bssn’s cybersecurity policy documents, and relevant indonesian cybersecurity regulations. these sources provide detailed insights into the formulation and implementation of policies in response to evolving cyber threats. to ensure that findings were reliable and valid, content analysis was conducted in stages. first, a thorough review of documents was performed, followed by open coding to identify recurring themes. this was followed by axial coding to group-related themes, enabling a more focused analysis of challenges and successes in the tni’s formation of the cyber force. modifications of krippendorff [20] method included a case study approach to assess specific incidents of cyberattacks on indonesia’s critical infrastructure. this case study method allowed for the exploration of strategic and policy implications in real-world contexts. 3. results and discussion 3.1 research findings this study found that the formation of the tni cyber force is a response to the increasing complexity of cyber threats in indonesia and globally. according to data from fortinet [4], indonesia experienced over 35 million botnet attacks in the first quarter of 2023, with a significant increase in attack duration, reaching up to 83 days. botnets like ghost rat and mirai were frequently used for distributed denial of service (ddos) attacks and data theft. these findings highlight the importance of strengthening the military's cyber units to protect the country’s critical infrastructure. additionally, data from awanpintar.id [5] indicates that the number of cyberattacks in indonesia during the first half of 2024 reached 2.4 billion, a drastic increase compared to 347 million attacks in the same period the previous year. this further emphasizes the need for the establishment of the tni cyber force as part of the national defense strategy to counter these threats. in terms of policy, presidential regulation no. 82 of 2022 on the national cyber and encryption agency (bssn) regulates the coordination between bssn and the tni in the protection of cyber infrastructure. this research found that synergy between bssn and the tni cyber force is crucial in addressing the growing challenges in cybersecurity. as highlighted by chotimah [12], closer collaboration between these agencies will enhance the effectiveness of national cyber defense, especially in anticipating both domestic and international cyber threats. dss vol. 5, no. 2, 2024, pp. 74-83 78 regarding international law, the implementation of the tallinn manual 2.0 provides guidelines on how military cyber operations must comply with the laws of war. the tni cyber force needs to ensure that its operations remain within the boundaries of international law, especially concerning attacks that may impact civilian infrastructure. white [1] also underscores the importance of coordination between the military and civilian sectors in safeguarding a nation's digital sovereignty, as cyber threats can easily target vital civilian sectors. the research also revealed that indonesia ranks 49th globally in the national cybersecurity index (ncsi) 2023, with a score of 63.64. although this ranking has improved from 83rd place in 2022, indonesia still needs to increase its cybersecurity readiness, particularly as attacks on critical infrastructure, such as the national data center (pdn), have been rising, with a ransomware attack by lockbit 3.0 occurring in mid2024 [9]. this study uncovers several critical facts regarding the formation of the tni cyber force and the cybersecurity challenges faced by indonesia. the following table 2 summarizes the key findings: table 2. key research findings on the formation of the tni cyber force category data source number of botnet attacks in indonesia (q1 2023) 35,911,749 attacks, with ghost rat leading (19.87% growth) fortinet [4] botnet duration botnet duration increased to 83 days (2023), 1,000x longer than in previous years fortinet [4] number of cyberattacks in indonesia (h1 2024) 2.4 billion attacks (up from 347 million attacks in the same period the previous year) awanpintar.id [5] bssn and tni coordination synergy between bssn and the tni cyber force is needed to protect national cyber infrastructure presidential regulation no. 82 of 2022 [21] indonesia’s cybersecurity ranking indonesia ranked 49th globally in the ncsi 2023 with a score of 63.64 ncsi [22] ransomware attack on pdn lockbit 3.0 ransomware attack targeted the national data center in mid-2024 tirto.id [9] international law on cyber warfare tni cyber force operations must comply with international law, as outlined in the tallinn manual 2.0 white [1] (sources: fortinet [4]; awanpintar.id [5]; presidential regulation no. 82 of 2022 [21]; ncsi [22]; tirto.id [9], white [1].) the table shows that the significant number of cyberattacks in indonesia, particularly botnet and ransomware attacks, underscores the urgency of forming the tni cyber force. data from fortinet (2023) highlights the sharp increase in botnet attack duration, leaving indonesia's digital infrastructure vulnerable for extended periods. moreover, with over 2.4 billion cyberattacks in the first half of 2024 [5], the creation of a military cyber unit becomes a strategic step in tackling these massive threats. coordination between bssn and the tni cyber force is crucial to ensure the protection of national cyber infrastructure, as stipulated by presidential regulation no. 82 of 2022. one of the challenges includes ensuring that the tni operates within the framework of international law, as explained in the tallinn manual 2.0 [23]. despite indonesia’s significant improvement in cybersecurity rankings, rising from 83rd place in 2022 to 49th place in the ncsi 2023, more intensive efforts are required to reach a higher level of cyber readiness. the ransomware attack on the national data center (pdn) also highlights the need to bolster the security of strategic data, particularly in government institutions [9]. these findings confirm that the tni cyber force is not only a crucial instrument in national defense but also requires cross-sector synergy and adherence to international law in conducting cyber operations. dss vol. 5, no. 2, 2024, pp. 74-83 79 3.2 interpretation of research findings the findings of this research reveal the importance of establishing the tni cyber force as part of a national defense strategy that is responsive to the increasing cyber threats in indonesia. the sharp rise in cyberattacks, particularly botnet and ransomware attacks, indicates significant vulnerabilities to the country's critical infrastructure. the data presented shows that more than 35 million botnet attacks were recorded in the first quarter of 2023, with botnet attack durations increasing to 83 days. this illustrates that cyber threats are becoming more persistent and require stronger and better-coordinated defense measures. the surge in cyberattacks from 347 million in the first half of 2023 to 2.4 billion in the first half of 2024 represents a substantial increase, highlighting how rapidly these threats are evolving. this underscores the urgent need for the tni, through the cyber force, to play a more active role in safeguarding the nation’s digital infrastructure. the coordination between bssn and the tni cyber force, as regulated by presidential regulation no. 82 of 2022, is critical to ensuring that both institutions can effectively address dynamic and targeted cyber threats. although indonesia has improved its cybersecurity score, rising from 83rd place in 2022 to 49th place in 2023 on the national cybersecurity index (ncsi), the continuing rise of cyber threats emphasizes that efforts to strengthen cyber defense must be accelerated. this improvement in the score indicates progress in national cyber readiness, yet there remain gaps that must be addressed, especially in securing strategic government infrastructure, as seen from the ransomware attack on the national data center (pdn) in 2024. in an international context, the operations of the tni cyber force must remain within the boundaries of international law governing the use of cyber force, as outlined in the tallinn manual 2.0. this means that any military actions conducted by the tni's cyber unit, particularly regarding cyber aggression, must comply with the laws of war and protect civil rights as well as critical infrastructure that may be impacted. overall, these findings indicate that the tni cyber force has the potential to become a key instrument in addressing the growing cyber threats in indonesia. however, institutional strengthening, cross-sector coordination, and compliance with both national and international regulations are necessary for it to function optimally in protecting the country’s digital sovereignty. 3.3 comparison with literature the findings of this research show that the formation of the tni cyber force aligns with global trends in which countries are increasingly strengthening their cyber defenses as part of their national security strategies. research by hatch [2] indicates that countries such as the united states and russia have long-established military cyber units to address the continuously evolving cyber threats. similarly, the establishment of the tni cyber force reflects indonesia's need to adapt to new defense dynamics, particularly with the growing complexity of threats like botnets and ransomware. this finding is supported by the fortinet report [4], which recorded a surge in botnet attack durations of up to 83 days, highlighting that these threats are becoming more persistent and difficult to manage with conventional defense approaches. additionally, sarjito [24] emphasizes the importance of collaboration between military and civilian agencies to enhance the effectiveness of cyber defense. in the context of indonesia, the synergy between bssn and the tni cyber force, as regulated by presidential regulation no. 82 of 2022, is crucial. this research is consistent with the literature that stresses cross-institutional cooperation as a key element in building resilient cyber defense. this is further reinforced by white's study [1], which underscores the need for coordination between civilian and military sectors in facing cyber threats that are global and interconnected. from an international legal perspective, the research findings also align with the principles outlined in the tallinn manual 2.0. as explained in the manual, cyber operations conducted by the military must comply with international law, including the laws of war, to ensure that any cyber actions taken do not violate human rights or target critical civilian infrastructure. these findings are consistent with the arguments in the literature, dss vol. 5, no. 2, 2024, pp. 74-83 80 which assert that legal boundaries in cyber operations are essential to maintaining the legitimacy of military actions in cyberspace. the comparison between these findings and the existing literature demonstrates that indonesia is following the global trend of strengthening national cyber defenses. however, the literature also highlights that indonesia still needs to enhance its cyber capabilities and infrastructure, as reflected by the significant rise in cyberattacks in 2024. while awanpintar.id [5] reported a surge in cyberattacks reaching 2.4 billion in the first half of 2024, comparisons with other countries reveal that indonesia's cyber readiness, though improving, still lags behind some neighboring southeast asian nations such as malaysia and singapore, which rank higher in the national cybersecurity index (ncsi). thus, the findings of this research are consistent with the existing literature but also highlight the need for more intensive policy reinforcement, strategic planning, and institutional synergy to ensure that the tni cyber force can effectively address the ever-evolving cyber threats. 3.4 theoretical implications this research reinforces the importance of integrating cyber capabilities into military defense, in line with the concept of cyber warfare, which is increasingly recognized as a key component of modern national security [2]. additionally, the theory of collective security, which involves cross-agency synergy, is highly relevant, as demonstrated by the coordination between the tni cyber force and the national cyber and encryption agency (bssn) in addressing rapidly evolving cyber threats [1]. this supports the idea that cybersecurity requires both national and international collaboration, as outlined in the tallinn manual 2.0 on the regulation of cyber operations by states [23]. the formation of the tni cyber force also strengthens the theory of defense systems, where cyberspace is considered an essential component of a nation's broader defense system, which must be integrated with air, land, and sea forces [3]. 3.5 practical implications this research provides several significant practical implications related to the formation of the tni cyber force in addressing increasingly complex cyber threats. first, the findings emphasize the importance of enhancing human resource capacity in cyber defense. the tni cyber force requires personnel who are specially trained to manage cyber threats, including the ability to detect, respond to, and mitigate technical and targeted attacks. investment in cybersecurity training and certification for military personnel is a crucial step toward strengthening national cyber resilience. second, the synergy between the national cyber and encryption agency (bssn) and the tni cyber force must be reinforced through improved coordination and information sharing regarding cyber threats. the research indicates that inter-agency cooperation is essential to create a more holistic and integrated cyber defense system. this could be achieved by establishing clear cooperation protocols and a shared platform for real-time threat data exchange between bssn and the tni. third, the tni cyber force needs to implement advanced cybersecurity technologies and infrastructure, including artificial intelligence (ai)-based technology to quickly detect evolving threats, as identified in the fortinet report [4]. the use of ai and machine learning technologies in monitoring cyber threats can enhance response speed to attacks and help prioritize vulnerability patching in defense systems. fourth, the tni cyber force should strengthen international relations and expand participation in global forums discussing cybersecurity, as recommended by the tallinn manual 2.0. this is necessary to ensure that cyber operations comply with international law and to gain access to relevant global cyber intelligence. active participation in international cooperation will enable indonesia to better protect its strategic infrastructure from global-scale attacks. dss vol. 5, no. 2, 2024, pp. 74-83 81 fifth, the formation of the tni cyber force lays the foundation for raising cybersecurity awareness across government institutions and the private sector. the research shows that with the growing number of cyberattacks, it is vital for the government to prioritize cybersecurity not only in the military sector but also in other critical sectors such as energy, transportation, and finance. implementing policies that emphasize preventive cybersecurity measures across all layers will strengthen overall national digital security. thus, the practical implications of this research include enhancing personnel training, inter-agency cooperation, adopting cutting-edge technologies, fostering international collaboration, and spreading cybersecurity awareness nationwide. 3.6 research limitations and future research this study has several limitations that should be noted. first, it relies primarily on secondary data, which means it does not include direct interviews with policymakers or military personnel involved in the formation of the tni cyber force. this limits the depth of understanding regarding the internal processes related to the establishment and operationalization of the cyber force. more in-depth information obtained through direct interviews or field observations could provide a more comprehensive picture of the institutional dynamics and challenges faced by the tni cyber force. second, the research focuses on national policy and does not thoroughly examine how international cybersecurity policies influence the strategies of the tni cyber force. given that cybersecurity issues are cross-border in nature and heavily influenced by global dynamics, this limitation results in an analysis that lacks consideration of the direct impact of international legal frameworks and cybersecurity strategies on domestic policy. third, the study is more focused on the strategic and policy aspects, with limited emphasis on the technical aspects of the tni cyber force's formation, such as the technological infrastructure and cyber operational systems utilized. further technical exploration into the technologies adopted by the cyber force, such as the use of artificial intelligence, cybersecurity systems, and protocols employed to counter cyberattacks, would provide deeper insights into the operational readiness of the tni's cyber unit. based on the limitations mentioned above, future research can focus on several key areas. first, field research using qualitative methods, involving in-depth interviews with military policymakers and cybersecurity experts, could provide sharper insights into the formation and operationalization of the tni cyber force. this research could also include perspectives from the private sector that collaborates with the tni to strengthen national cybersecurity. second, international comparative research could be conducted to compare military cybersecurity strategies in indonesia with other countries that are more advanced in developing military cyber units, such as the united states, russia, and china. this would help identify best practices that indonesia could adopt to strengthen its cyber defense. third, future research could also focus on the technical aspects of cyber defense, such as the technologies used in detecting and responding to cyber threats. this could include studies on the effectiveness of artificial intelligence (ai) and machine learning in managing cyber threats in the military domain. fourth, further studies on the international legal framework related to cyber warfare and indonesia’s involvement in global cybersecurity forums could also be an important direction for future research. this research could explore how international regulations influence the operations of the tni cyber force and to what extent indonesia complies with global norms in conducting military cyber operations. by addressing these limitations and exploring broader and deeper research areas, future studies can contribute more comprehensively to understanding the role and effectiveness of the tni cyber force in tackling cyber challenges in the modern era. dss vol. 5, no. 2, 2024, pp. 74-83 82 4. conclusions this study emphasizes the critical role of the tni cyber force in responding to the growing complexity and volume of cyber threats in indonesia. the rise in cyberattacks, particularly botnet and ransomware incidents, highlights the urgent need for a dedicated military cyber unit to enhance national cybersecurity, protect vital infrastructure, and maintain digital sovereignty. the significant increase in attacks, as indicated by data from fortinet [4] and awanpintar.id (2024) [5], underscores this necessity. the collaboration between the tni cyber force and the national cyber and encryption agency (bssn), as mandated by presidential regulation no. 82 of 2022, is essential for effectively countering cross-border and dynamic cyber threats. furthermore, ensuring compliance with international laws, such as those detailed in the tallinn manual 2.0, is vital for maintaining the legitimacy of tni’s cyber operations within the global legal framework. while indonesia has made progress in improving its cybersecurity, as evidenced by its rising rank in the 2023 national cybersecurity index (ncsi), significant challenges remain. these include the need for enhanced human resources, the adoption of advanced technologies, and increased international cooperation to further strengthen the nation’s cyber defense capabilities. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. declaration of use 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[24] a. sarjito, “national defense ecosystem model based on collaboration between government, industry and society,” jisip unja (jurnal ilmu sosial ilmu politik universitas jambi), pp. 32–44, 2024 microsoft word 29-45_264 (online) issn 2744-1741 defense and security studies original research vol. 5, no. 1, 2024, pp. 29-45 https://doi.org/10.37868/dss.v5.id264 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 29 theoretical study on the sabot separation process of a sub-caliber projectile fired from rifled guns bui xuan son1, nguyen quang tuan1*, nguyen hai minh1, doan van dung1 1faculty of special equipments, le quy don technical university, vietnam. *corresponding author e-mail: tuannguyenmta28@gmail.com received: jun. 6, 2024 revised: jul. 7, 2024 accepted: jul. 9, 2024 online: jul. 14. 2024 abstract sub-caliber projectiles have been widely used in modern warfare due to their ability to enhance accuracy and ballistic performance. for such projectiles, however, an effective separation of the penetrator from the sabot upon exiting the barrel is extremely important for achieving the desired accuracy and terminal ballistics. in this paper, we present a theoretical model for studying the aspects of the penetrator-sabot separation process for a sub-caliber projectile fired from 7.62mm pistols. the method used in this paper is a combination of analytical and numerical approaches. firstly, an equation system was analytically established to describe the motion of the sabot and the penetrator in absolute coordinates. then, the computational fluid dynamics simulation approach was applied to determine the aerodynamic forces acting on the sabot and the penetrator. finally, the equation system was solved using newton’s method to calculate the position of the sabot and the penetrator during the separation process. based on the proposed model, the effect of some parameters on the separation process was investigated. the investigation results have shown that the initial friction force between the sabot and the penetrator significantly influences the separation process. the findings in this study provide valuable contributions to the design and optimization of sub-caliber projectile-weapon systems. © the author 2024. published by arda. keywords: sabot separation; sub-caliber projectile; cfd method, armor-piercing power; saboted projectile, penetrator 1. introduction to enhance the armor penetration power of projectiles, various solutions have been applied in weapon design practice. one such way is to use sub-caliber projectiles. central to the functionality of these projectiles is the sabot, a carrier structure that encases the projectile during its initial flight stage before separating to allow the penetrator to continue flying alone towards the intended target. in le quy don technical university, an intensive research program has been carried out to find ways to enhance the armor-piercing performance of rifled guns for infantry, focusing on perspective cartridge projectile designs. one of our chosen designs is the design with sabot, the typical structure of which is dss vol. 5, no. 1, 2024, pp. 29-45 30 presented in figure 1. the projectile consists of an aluminum sabot and a tungsten carbide penetrator. the penetrator separates from the sabot due to the difference in aerodynamic drags acting on the sabot and the penetrator. the separation begins upon exiting the barrel until the penetrator completely loses mechanical contact with the sabot (figure 2). figure 1. the structure of a sub-caliber projectile fired from rifled guns figure 2. the penetrator gradually separates from the sabot the penetrator-sabot separation process is an important stage in the flight trajectory of sub-caliber projectiles, influencing their stability, accuracy, and terminal effectiveness. numerous researches have been conducted on the separation process of apfsds (armor-piercing fin-stabilized discarding sabot). several scholars have carried out experiments to visually observe and analyze the sabot discard process. others have employed computational fluid dynamics (cfd) methods to numerically investigate the effect of different parameters, such as muzzle velocity, sabot geometry dimensions, and launch conditions on the separation process [1-5]. the apfsds projectiles are fired from smoothbore barrels. the penetrator of apfsds has fins to stabilize its flight. as the apfsds projectile exits the barrel, the sabot and the penetrator almost immediately lose mechanical contact. the working principle of apfsds projectiles is different from that of sub-caliber projectiles fired from rifled guns. consequently, it is inappropriate to apply these research results to the subcaliber projectiles fired from rifled guns. regarding spin-stabilized saboted projectiles, walling et al. conducted experiments to study the interior and exterior ballistics of a 20 mm saboted penetrator projectile [6]. nguyen et al. numerically investigated the supersonic flow around a saboted bullet fired from 7.62 mm pistols similar to 6.5x25 mm cbj apds rounds [7]. analysis of the available literature related to saboted projectiles showed that very few works have been devoted to sub-caliber projectiles fired from rifled guns and, to the best of our knowledge, so far there have been no published studies concerning the theoretical study of the motion of spin-stabilize projectiles during the separation process. hence, the main objective of this paper is to establish a theoretical model to investigate the sabot separation process for sub-caliber projectiles fired from rifled guns, outlining the theoretical framework, mathematical model, and computational method as well. penetrator sabot dss vol. 5, no. 1, 2024, pp. 29-45 31 2. research methodology 2.1. equation systems describing the motion of the sabot and the penetrator to establish a mathematical model describing the motion of the sabot and the penetrator upon exiting the barrel, the following assumptions are implemented: the trajectory of the projectile is flat (the gravitational force does not affect its trajectory); the angle of attack of the projectile is zero; the rotational motion of the projectile does not affect its translational motion. let us consider the motion of two material points os and op respectively under the action of the aerodynamic drags and the friction force between the sabot and the penetrator, where os is the center of the cross-section of the sabot bottom surface, and op is the center of the cross-section of the penetrator aft surface, as shown in figure 3. figure 3. the position of two material points os and op a one-dimensional cartesian coordinate system is next selected for the sabot and the penetrator, as shown in figure 4. figure 4. the forces acting on the sabot (os) and on the penetrator (op) the origin o of the coordinate system is the center of the cross-section of the penetrator aft surface at the moment the projectile exits the barrel. that means, at the very moment when the projectile exits the barrel, three points o, os, and op coincide. the positive direction of the coordinate axis is the direction of the projectile muzzle velocity vector. according to theoretical physics, the equations describing the motion of the sabot can be stated as follows: �̇� = −𝐹 + 𝐹 𝑚 �̇� = 𝑣 , (1) where 𝑣 is the current velocity of the sabot; 𝑥 is the current coordinate of the sabot; 𝐹 is the aerodynamic drag on the sabot; ffr is the friction between the sabot and the penetrator; 𝑚 is the mass of the sabot. similarly, the equations describing the motion of the penetrator are as follows: �̇� = −𝐹 − 𝐹 𝑚 �̇� = 𝑣 , (2) where 𝑣 is the current velocity of the penetrator; 𝑥 is the current coordinate of the penetrator; 𝐹 is the aerodynamic drag on the penetrator; and 𝑚 is the mass of the penetrator. dss vol. 5, no. 1, 2024, pp. 29-45 32 at the initial moment when the projectile is exiting the barrel: 𝑣 = 𝑣 = 𝑣 ; 𝑥 = 𝑥 = 0, (3) where vs0 is the initial velocity of the sabot; vp0 is the initial velocity of the penetrator; v0 is the muzzle velocity of the projectile; xs0 is the initial coordinate of the sabot; xp0 is the initial coordinate of the penetrator. the friction between the sabot and the penetrator is determined through the following expression: 𝐹 = 𝑓 𝑝𝑆, (4) where ffr is the friction coefficient between the sabot and the penetrator; p is the specific pressure on the contact surface between the sabot and the penetrator it depends on the mechanical interference of the sabot and the penetrator; and s is the area of the contact surface between the sabot and the penetrator: 𝑆 = 𝜋𝑑 𝑙, (5) where dp is the diameter of the penetrator; l is the length of longitudinal contact between the sabot and the penetrator at the current moment as illustrated in figure 5. figure 5. the length of longitudinal contact (l) between the sabot and the penetrator the parameter l is determined (fig. 5) as follows: 𝑙 = 𝑙 − (𝑥 − 𝑥 ). (6) where l0 is the initial length of longitudinal contact between the sabot and the penetrator. the separation process is considered to be completed if there is no mechanical contact between the sabot and the penetrator, which means l = 0. substituting (5) into (4), we can write: 𝐹 = 𝑓 𝑝𝜋𝑑 𝑙 = 𝑓 𝑝𝜋𝑑 𝑙 ∙ . (7) naming 𝐹 = 𝑓 𝑝𝜋𝑑 𝑙 , it is easy to realize that 𝐹 is the initial friction force between the sabot and the penetrator at the very moment when the projectile leaves the gun barrel; it depends on the material properties of the sabot and the penetrator, mechanical interference fit between the sabot and the penetrator, and on the dimensions of the penetrator. consequently, the expression (7) can be rewritten as follows: 𝐹 = 𝐹 ∙ . (8) it is obvious from (8) that the current frictional force between the sabot and the penetrator is linearly dependent on their initial frictional force. 2.2. solution method the equation system (1), (2), (6), (8) with initial condition (3) can be solved using numerical methods, if we know the aerodynamic drag fds and fdp at any time step. to achieve this goal, firstly, these aerodynamic drags are obtained numerically at certain discrete points using the ansys fluent software package [8]. then, fds and fdp at any time step will be approximated. with fixed dimensions of the sabot and the penetrator, the dss vol. 5, no. 1, 2024, pp. 29-45 33 aerodynamic drags on the sabot and penetrator will depend on their velocity and their relative position. that means they can be presented in the following form: ( , ),ds ds sf f v l 𝐹 = 𝐹 (𝑣 , 𝑙). (9) using numerical simulation method with ansys fluent software package we can obtain fds and fdp at discrete points. to approximate them at any point we use the bilinear interpolation method. 2.3. procedure for obtaining the aerodynamic drag in general, aerodynamic drag force can be obtained using semi-empirical prediction codes, like the missile datcom and prodas, experimental methods, such as wind tunnels and spark ranges tests, or cfd methods. in this research, we have determined the aerodynamic drag on the sabot and the penetrator using cfd methods with the ansys fluent software package. the simulation procedure has been widely presented in multiple works [9-13]. to calculate the aerodynamic drags of the sabot and the penetrator, an air domain with the size of 40d x 10d x 10d was created, where d is the diameter of the sabot (d = 7.62mm). mesh sensitivity investigation showed that, in our case, for 3d rans simulation, the mesh of 3.8 million elements would give sufficiently accurate results. the mesh around the projectile is presented in figure 6. in order to obtain drag on the sabot and the drag on the penetrator separately, we have named the penetrator surface and the sabot surface with different names as shown in figure 7. other setting parameters for ansys fluent simulation used in this study are presented in table 1. figure 6. the mesh for the projectile a) b) figure 7. named selections for the penetrator (a) and the sabot (b) table 1. the main setting parameters in ansys fluent parameter value turbulence model k-ε solver density-based air model ideal gas viscosity model sutherland algorithm coupled convergence criteria 10-5 the numerically obtained values of aerodynamic drag on the sabot and the penetrator are presented in appendix 1 and appendix 2. to visually observe the supersonic flow in simulation, examples of the flow around the sabot and the penetrator at their velocities and relative positions are presented in figure 8-11. dss vol. 5, no. 1, 2024, pp. 29-45 34 figure 8. the pressure distribution around the saboted projectile at v = 620 m/s and l = 0 mm figure 9. the velocity distribution around the saboted projectile at v = 620 m/s and l = 0 mm figure 10. the pressure distribution around the saboted projectile at v = 680 m/s and l = 5 mm dss vol. 5, no. 1, 2024, pp. 29-45 35 figure 11. the velocity distribution around the saboted projectile at v = 680 m/s and l = 5 mm 2.4. approximating the aerodynamic drag after obtaining the aerodynamic drags on the sabot and the penetrator at discrete points of their velocity and their relative position, we will approximate them at any time step based on their current velocity and relative position using the bilinear interpolation method. supposing that, using ansys fluent simulation software we have obtained aerodynamic drag f at four points f11(v1,l1), f12(v1,l2), f21(v2 l1), f22(v2,l2). according to the bilinear interpolation method, the value of any f(v,l), where 𝑣 < 𝑣 < 𝑣 and 𝑙 < 𝑙 < 𝑙 , can be approximated by the following expression [14]: 𝐹(𝑣, 𝑙) = 𝐹 + (𝐹 − 𝐹 ) 𝑣 − 𝑣 𝑣 − 𝑣 + (𝐹 − 𝐹 ) 𝑙 − 𝑙 𝑙 − 𝑙 + (𝐹 − 𝐹 − 𝐹 + 𝐹 ) (𝑣 − 𝑣 )(𝑙 − 𝑙 ) (𝑣 − 𝑣 )(𝑙 − 𝑙 ) . 2.5. result verification though the research method has been carefully established, the calculated results should be compared to experimental results to verify the accuracy of the method. as no relevant experimental data has been published in open literature so far, there are some limitations regarding result verification. nevertheless, the main purpose of this paper is to conduct a theoretical study on the separation process of a saboted projectile; hence, experiments can be carried out later as a further development of this work to verify the comprehensive study model for the separation phenomenon. 3. results and discussion the sabot separation process is complex, and influenced by numerous factors, including aerodynamic forces and launch conditions. understanding these dynamics is crucial for optimizing the accuracy and effectiveness of sub-caliber projectile systems. in this paper, the influence of the muzzle velocity of the projectile and the initial friction between the sabot and the penetrator on the sabot separation process was investigated using above established mathematical model. namely, we have investigated their influence on the penetrator velocity at the moment it separates from the sabot and on the distance the penetrator travels to the separation point (the separation distance). the main dimensions of the penetrator and the sabot are shown in figure 12 and figure 13. figure 12. the dimensions of the penetrator dss vol. 5, no. 1, 2024, pp. 29-45 36 figure 13. the dimensions of the sabot in addition, the main parameters of the projectile are presented in table 2. table 2. the main parameters of the sub-caliber projectile parameter units notation value mass of the aluminum sabot kg ms 0.00089 mass of the tungsten carbide penetrator kg mp 0.00274 the initial length of longitudinal contact m l 0.009 using the ansys fluent software package we have obtained aerodynamic drag fds(vs,l) and fdp(vp,l) as discrete functions of their velocity and parameter l: the velocity ranges from 630 m/s to 700 m/s with an increment of 10 m/s, the parameter l changes from 0 m to 0.009 m with an increment of 0.001 m. a code has been written in delphi programming language [15] for approximating aerodynamic drags and solving the equation system (1), (2),(6), (8) with initial condition (3) to find the velocity of the projectile at the separation moment and the separation distance. the code is presented in appendix 3. 3.1. the effect of the projectile muzzle velocity projectile muzzle velocity is one of the most important parameters, influencing the trajectory, range, and terminal power of the projectile. in this research, to analyze the effect of the projectile muzzle velocity, we have investigated the sabot separation process with projectile muzzle velocity of 700 m/s, 680 m/s, 660 m/s, and 640 m/s. the influence of the projectile muzzle velocity on the penetrator velocity at the separation moment and on the separation distance is presented in figure 14 and figure 15 with different initial friction forces between the sabot and the penetrator. the dependence of the penetrator velocity at the separation moment on the projectile muzzle velocity is almost linear and nearly identical for different initial friction forces between the sabot and the penetrator (figure 14). in the contrary, the influence of the projectile muzzle velocity on the separation distance is dependent on the initial friction force between the sabot and the penetrator (figure 15). the greater the initial friction force the clearer the projectile muzzle velocity affects the separation distance. at the initial friction force of 2 n, the separation distance only slightly changes with the change of the projectile muzzle velocity. but at the initial friction force of 6 n, the projectile muzzle velocity significantly affects the separation distance. moreover, we can see clearly that, the penetrator completely separates from the sabot at the distance of about 1 m to 1.8 m from the gun muzzle. this information helps us to appropriately setup high-speed camera to capture the separation process for further analysis and development. dss vol. 5, no. 1, 2024, pp. 29-45 37 figure 14. the influence of projectile muzzle velocity on the penetrator velocity at separation moment at different initial friction forces between the sabot and the penetrator figure 15. the influence of projectile muzzle velocity on the separation distance at different initial friction forces between the sabot and the penetrator 3.2. the effect of the initial friction force between the sabot and the penetrator the initial friction force between the sabot and the penetrator is a crucial parameter, affecting the dynamics of the separation process and the transportation, storage, and usage of saboted projectiles. the initial friction force must be appropriately selected to ensure reliable sabot separation, on the one hand, and the integrity of the projectile on the other hand. in this study, the sabot separation process was investigated with initial friction dss vol. 5, no. 1, 2024, pp. 29-45 38 force from 2 n to 7 n to see its effect. the influence of the initial friction force on the penetrator velocity at the separation moment and on the separation distance is shown in figure 16 and figure 17. figure 16. the influence of the initial friction force on the penetrator velocity at separation moment at different projectile muzzle velocities figure 17. the influence of the initial friction force on the separation distance at different projectile muzzle velocities it is easy to see that if the initial friction force increases then the penetrator velocity at the separation moment decreases. moreover, the greater the initial friction force, the more penetrator velocity at the separation moment drops. at an initial friction force of 2 n, the penetrator velocity loss is about 0.4% to 1% depending on the projectile muzzle velocity, while at an initial friction force of 7 n, the penetrator velocity loss is about 0.8% to 2% depending on the projectile muzzle velocity. the greater the projectile muzzle velocity, the less dss vol. 5, no. 1, 2024, pp. 29-45 39 the penetrator velocity loss. in addition, if the initial friction force increases, the separation distance also increases quickly. at the initial friction force of 2 n, the separation distance is about 1 m, but, at the initial friction force of 7 n, the separation distance is about 1.6 m to 1.8 m. thus, it can be affirmed that the initial friction force between the sabot and the penetrator has a very significant influence on the decrease of the penetrator velocity at the time it completely separates from the sabot, and also on the separation distance. in the process of designing and manufacturing saboted projectiles, it is necessary to select the initial friction force appropriately to ensure that the penetrator connects reliably with the sabot during transportation, storage, and reloading and that the penetrator can reliably and promptly separate from the sabot after the projectile exiting the gun barrel. in this case, the initial friction force should be between 3 n and 7 n to ensure a reliable connection between the sabot and the penetrator and ensure that the separation process occurs beyond the aftereffect period of gunpowder gas. 4. conclusions in this research, a theoretical model was proposed for studying the sabot separation process of a sub-caliber projectile fired from rifled guns. based on this model, an investigation was conducted to analyze the effect of the initial friction force between the sabot and the penetrator and the effect of the projectile muzzle velocity on the separation process. the results have shown a significant influence of the initial friction force on the penetrator velocity at the separation moment and on the separation distance. the separation distance varies from about 1 m to 1.8 m. the appropriate initial friction force between the sabot and the penetrator should be from 3 n to 7 n. the research methodology and results presented in this study can be applied in the design process to enhance the effectiveness of saboted projectile-weapon systems. 5. future work the following directions are recommended for further continuation of this study: 1. the first direction is to investigate the influence of the structural parameters of the sabot on the separation process. 2. the second direction is to numerically investigate the sabot separation process of sub-caliber projectiles fired from a rifled gun using the fluid-structure interaction (fsi) approach and then compare the obtained results with the results of this study. 3. the third direction is to conduct live firing tests to verify and validate the reliability and accuracy of the established mathematical model and computational method. funding information this research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. declaration of competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. references [1] c. zhang, h. wang, t. liu, and y. duo, "sabot discard characteristics under different spin rates of the rifled barrel launching apfsds," shock and vibration, vol. 2021, 2021. [2] r. cayzac, e. carette, and s. heddadj, "complex aerodynamics behavior of high spin apfsds projectile," international journal of applied mechanics, vol. 80, no. 3, pp. 1-7, 2013. [3] z. hoang and z. chen, "numerical simulation on three-dimensional dynamic process of sabot discarding of apfsds," acta armamentarii, vol. 35, no. 1, pp. 9-17, 2014. dss vol. 5, no. 1, 2024, pp. 29-45 40 [4] l. huang and c. lai, "systematic study and numerical simulation of sabot projectile aerodynamics," journal of the chinese institute of engineers, vol. 20, no. 3, pp. 275-284, 1997. [5] a. trakic, "axial force coefficient of apfsds projectile," defense and security studies, vol. 1, pp. 1-15, 2020. [6] h. c. walling, t. j. roemer, and k. svensson, "interior and exterior ballistic development of a 20mm saboted penetrator projectile," sandia national laboratories, 1997. [7] q. t. nguyen, h. m. nguyen, and x. s. bui, "numerical investigation on the supersonic flow around a saboted bullet," military technical courier, vol. 72, no. 2, pp. 676-694, 2024. [8] j. e. matsson, an introduction to ansys fluent 2023, sdc publications, 2023. [9] a. catovic and e. kljuno, "prediction of aerodynamic coefficients for the irregularly shaped body using numerical simulations," international journal of advanced and applied sciences, vol. 5, no. 7, pp. 71-85, 2018. [10] a. ferfouri, t. allouche, d. d. jerkovic, n. hristov, m. vuckovic, and a. benmeddah, "prediction of drag aerodynamic coefficient of the 155 mm projectile under axisymmetric flow using different approaches," journal of the serbian society for computational mechanics, vol. 17, no. 2, pp. 69-86, 2023. [11] a. khan, i. shah, a. aziz, m. waqas, u. k. zaman, and d. jung, "numerical and experimental analysis of drag and lift forces on a bullet head," aerospace, vol. 9, pp. 1-16, 2022. 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[15] j. barrow, l. miller, k. malan, and h. gelderblom, introducing delphi programming: theory through practice, 4th ed., oxford university press, 2005. dss vol. 5, no. 1, 2024, pp. 29-45 41 appendix 1. the aerodynamic drag on the sabot, obtained using ansys fluent fds(n) l (m) 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 v(m/s) 700 12.40 13.00 10.41 10.76 9.46 9.19 9.74 9.46 9.64 9.23 690 12.07 12.49 10.19 10.49 9.15 8.96 9.45 9.12 9.38 9.08 680 11.78 12.03 10.01 10.27 8.83 8.67 9.13 8.66 9.15 8.96 670 11.37 11.72 9.78 10.01 8.75 8.35 8.90 8.56 9.01 8.84 660 10.98 11.29 9.58 9.70 8.64 8.06 8.62 8.40 8.83 8.78 650 10.72 10.84 9.45 9.48 8.48 7.98 8.44 8.18 8.60 8.57 640 10.26 10.58 9.11 9.43 8.34 7.95 8.24 8.02 8.32 8.30 630 9.78 10.15 8.93 9.01 8.23 7.73 7.98 7.68 7.97 8.02 dss vol. 5, no. 1, 2024, pp. 29-45 42 appendix 2. the aerodynamic drag on the penetrator, obtained using ansys fluent fdp(n) l (m) 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 v(m/s) 700 4.23 2.64 1.45 1.46 1.47 1.48 1.49 1.51 1.52 1.53 690 4.14 2.61 1.42 1.43 1.43 1.44 1.45 1.47 1.48 1.49 680 4.09 2.59 1.39 1.40 1.41 1.41 1.42 1.44 1.45 1.46 670 4.07 2.55 1.36 1.37 1.37 1.38 1.38 1.40 1.42 1.43 660 3.93 2.49 1.33 1.34 1.34 1.35 1.35 1.37 1.38 1.40 650 3.86 2.47 1.28 1.30 1.31 1.31 1.32 1.34 1.35 1.36 640 3.74 2.44 1.26 1.27 1.28 1.28 1.29 1.32 1.32 1.33 630 3.63 2.41 1.23 1.24 1.25 1.25 1.26 1.27 1.27 1.28 dss vol. 5, no. 1, 2024, pp. 29-45 43 appendix 3. the code, written in delphi programming language for approximating aerodynamic drags and solving the equations of motion of the sabot and the penetrator unit unit1; interface uses winapi.windows, winapi.messages, system.sysutils, system.variants, system.classes, vcl.graphics, vcl.controls, vcl.forms, vcl.dialogs, vcl.stdctrls; implementation {$r *.dfm} {input of the initial structural parameters} procedure tform1.button3click(sender: tobject); begin edit1.text:='9'; edit2.text:='2'; edit5.text:=''; edit7.text:=''; edit8.text:='0.89'; edit9.text:='2.74'; edit10.text:='690'; edit11.text:='0.0000001'; edit12.text:=''; edit13.text:=''; end; procedure input1; begin l0:=strtofloat(form1.edit1.text)/1000; ffr0:=strtofloat(form1.edit2.text); ms:=strtofloat(form1.edit8.text)/1000; mp:=strtofloat(form1.edit9.text)/1000; v0:=strtofloat(form1.edit10.text); step:=strtofloat(form1.edit11.text); end; {input of the aerodynamic drags obtained from ansys fluent} procedure input2; begin vs0[1]:=700; vs0[2]:=690; vs0[3]:=680; vs0[4]:=670; vs0[5]:=660; vs0[6]:=650; vs0[7]:=640; vs0[8]:=630; vp0[1]:=700; vp0[2]:=690; vp0[3]:=680; vp0[4]:=670; vp0[5]:=660; vp0[6]:=650; vp0[7]:=640;vp0[8]:=630; ll0[1]:=0; ll0[2]:=1; ll0[3]:=2; ll0[4]:=3; ll0[5]:=4; ll0[6]:=5; ll0[7]:=6; ll0[8]:=7; ll0[9]:=8; ll0[10]:=9; fds0[1,1]:=12.40; fds0[1,2]:=13.00; fds0[1,3]:=10.41; fds0[1,4]:=10.76; fds0[1,5]:=9.46; fds0[1,6]:=9.19; fds0[1,7]:=9.74; fds0[1,8]:=9.46; fds0[1,9]:=9.64; fds0[1,10]:=9.23; fds0[2,1]:=12.07; fds0[2,2]:=12.49; fds0[2,3]:=10.19; fds0[2,4]:=10.49; fds0[2,5]:=9.15; fds0[2,6]:=8.96; fds0[2,7]:=9.45; fds0[2,8]:=9.12; fds0[2,9]:=9.38; fds0[2,10]:=9.08; fds0[3,1]:=11.78; fds0[3,2]:=12.03; fds0[3,3]:=10.01; fds0[3,4]:=10.27; fds0[3,5]:=8.83; fds0[3,6]:=8.67; fds0[3,7]:=9.13; fds0[3,8]:=8.66; fds0[3,9]:=9.15; fds0[3,10]:=8.96; fds0[4,1]:=11.37; fds0[4,2]:=11.72; fds0[4,3]:=9.78; fds0[4,4]:=10.01; fds0[4,5]:=8.75; fds0[4,6]:=8.35; fds0[4,7]:=8.90; fds0[4,8]:=8.56; fds0[4,9]:=9.01; fds0[4,10]:=8.84; fds0[5,1]:=10.98; fds0[5,2]:=11.29; fds0[5,3]:=9.58; fds0[5,4]:=9.70; fds0[5,5]:=8.64; fds0[5,6]:=8.06; fds0[5,7]:=8.62; fds0[5,8]:=8.40; fds0[5,9]:=8.83; fds0[5,10]:=8.78; fds0[6,1]:=10.72; fds0[6,2]:=10.84; fds0[6,3]:=9.45; fds0[6,4]:=9.48; fds0[6,5]:=8.48; fds0[6,6]:=7.98; fds0[6,7]:=8.44; fds0[6,8]:=8.18; fds0[6,9]:=8.60; fds0[6,10]:=8.57; fds0[7,1]:=10.26; fds0[7,2]:=10.58; fds0[7,3]:=9.11; fds0[7,4]:=9.43; fds0[7,5]:=8.34; fds0[7,6]:=7.95; fds0[7,7]:=8.24; fds0[7,8]:=8.02; fds0[7,9]:=8.32; fds0[7,10]:=8.30; fds0[8,1]:=9.78; fds0[8,2]:=10.15; fds0[8,3]:=8.93; fds0[8,4]:=9.01; fds0[8,5]:=8.23; fds0[8,6]:=7.73; fds0[8,7]:=7.98; fds0[8,8]:=7.68; fds0[8,9]:=7.97; fds0[8,10]:=8.02; dss vol. 5, no. 1, 2024, pp. 29-45 44 fdp0[1,1]:=4.23; fdp0[1,2]:=2.64; fdp0[1,3]:=1.45; fdp0[1,4]:=1.46; fdp0[1,5]:=1.47; fdp0[1,6]:=1.48; fdp0[1,7]:=1.49; fdp0[1,8]:=1.51; fdp0[1,9]:=1.52; fdp0[1,10]:=1.53; fdp0[2,1]:=4.14; fdp0[2,2]:=2.61; fdp0[2,3]:=1.42; fdp0[2,4]:=1.43; fdp0[2,5]:=1.43; fdp0[2,6]:=1.44; fdp0[2,7]:=1.45; fdp0[2,8]:=1.47; fdp0[2,9]:=1.48; fdp0[2,10]:=1.49; fdp0[3,1]:=4.09; fdp0[3,2]:=2.59; fdp0[3,3]:=1.39; fdp0[3,4]:=1.40; fdp0[3,5]:=1.41; fdp0[3,6]:=1.41; fdp0[3,7]:=1.42; fdp0[3,8]:=1.44; fdp0[3,9]:=1.45; fdp0[3,10]:=1.46; fdp0[4,1]:=4.07; fdp0[4,2]:=2.55; fdp0[4,3]:=1.36; fdp0[4,4]:=1.37; fdp0[4,5]:=1.37; fdp0[4,6]:=1.38; fdp0[4,7]:=1.38; fdp0[4,8]:=1.40; fdp0[4,9]:=1.42; fdp0[4,10]:=1.43; fdp0[5,1]:=3.93; fdp0[5,2]:=2.49; fdp0[5,3]:=1.33; fdp0[5,4]:=1.34; fdp0[5,5]:=1.34; fdp0[5,6]:=1.35; fdp0[5,7]:=1.35; fdp0[5,8]:=1.37; fdp0[5,9]:=1.38; fdp0[5,10]:=1.40; fdp0[6,1]:=3.86; fdp0[6,2]:=2.47; fdp0[6,3]:=1.28; fdp0[6,4]:=1.30; fdp0[6,5]:=1.31; fdp0[6,6]:=1.31; fdp0[6,7]:=1.32; fdp0[6,8]:=1.34; fdp0[6,9]:=1.35; fdp0[6,10]:=1.36; fdp0[7,1]:=3.74; fdp0[7,2]:=2.44; fdp0[7,3]:=1.26; fdp0[7,4]:=1.27; fdp0[7,5]:=1.28; fdp0[7,6]:=1.28; fdp0[7,7]:=1.29; fdp0[7,8]:=1.32; fdp0[7,9]:=1.32; fdp0[7,10]:=1.33; fdp0[8,1]:=3.63; fdp0[8,2]:=2.41; fdp0[8,3]:=1.23; fdp0[8,4]:=1.24; fdp0[8,5]:=1.25; fdp0[8,6]:=1.25; fdp0[8,7]:=1.26; fdp0[8,8]:=1.27; fdp0[8,9]:=1.27; fdp0[8,10]:=1.28; end; {approximating the aerodynamic drag on the sabot} function fds(a,b:real):real; var x,y:integer; f11,f12,f21,f22:real; begin if (a<=700) and (a>690) then x:=1; if (a<=690) and (a>680) then x:=2; if (a<=680) and (a>670) then x:=3; if (a<=670) and (a>660) then x:=4; if (a<=660) and (a>650) then x:=5; if (a<=650) and (a>640) then x:=6; if (a<=640) and (a>630) then x:=7; if (b<1) and (b>=0) then y:=1; if (b<2) and (b>=1) then y:=2; if (b<3) and (b>=2) then y:=3; if (b<4) and (b>=3) then y:=4; if (b<5) and (b>=4) then y:=5; if (b<6) and (b>=5) then y:=6; if (b<7) and (b>=6) then y:=7; if (b<8) and (b>=7) then y:=8; if (b<9) and (b>=8) then y:=9; f11:=fds0[x,y]; f12:=fds0[x,y+1]; f21:=fds0[x+1,y]; f22:=fds0[x+1,y+1]; fds:=f11+(f21-f11)*(a-vs0[x])/(vs0[x+1]-vs0[x])+(f12-f11)*(b-ll0[x])/(ll0[x+1]-ll0[x])+(f22-f12f21+f11)*(a-vs0[x])/(vs0[x+1]-vs0[x])*(b-ll0[x])/(ll0[x+1]-ll0[x]) end; {approximating the aerodynamic drag on the penetrator} function fdp(a,b:real):real; var x,y:integer; f11,f12,f21,f22:real; begin if (a<=700) and (a>690) then x:=1; if (a<=690) and (a>680) then x:=2; if (a<=680) and (a>670) then x:=3; if (a<=670) and (a>660) then x:=4; if (a<=660) and (a>650) then x:=5; if (a<=650) and (a>640) then x:=6; if (a<=640) and (a>630) then x:=7; if (b<1) and (b>=0) then y:=1; if (b<2) and (b>=1) then y:=2; if (b<3) and (b>=2) then y:=3; if (b<4) and (b>=3) then y:=4; if (b<5) and (b>=4) then y:=5; if (b<6) and (b>=5) then y:=6; if (b<7) and (b>=6) then y:=7; if (b<8) and (b>=7) then y:=8; if (b<9) and (b>=8) then y:=9; f11:=fdp0[x,y]; f12:=fdp0[x,y+1]; f21:=fdp0[x+1,y]; f22:=fdp0[x+1,y+1]; dss vol. 5, no. 1, 2024, pp. 29-45 45 fdp:=f11+(f21-f11)*(a-vp0[x])/(vp0[x+1]-vp0[x])+(f12-f11)*(b-ll0[x])/(ll0[x+1]-ll0[x])+(f22-f12f21+f11)*(a-vp0[x])/(vp0[x+1]-vp0[x])*(b-ll0[x])/(ll0[x+1]-ll0[x]); end; {solving the equations of motion of the sabot and the penetrator} procedure tform1.button1click(sender: tobject); var t,vs,xs,vp,xp,l,ffr:real; begin input1; input2; t:=0; vs:=v0; vp:=v0; xs:=0; xp:=0; l:=0; ffr:=ffr0; repeat t:=t+step; vs:=(-fds(vs,l)+ffr)/ms*step+vs; vp:=(-fdp(vp,l)-ffr)/mp*step+vp; xs:=vs*step+xs; xp:=vp*step+xp; l:=(xp-xs); ffr:=ffr0*(1-l/l0); until abs(l-l0)<=0.00001; form1.edit5.text:=floattostrf(xp,fffixed, 16, 2); form1.edit7.text:=floattostrf(vp,fffixed, 16, 2); form1.edit12.text:=floattostrf(vs,fffixed, 16, 2); form1.edit13.text:=floattostrf(t,fffixed, 16, 4); end; end. microsoft word 83-100_199 issn 2744-1741 defense and security studies original research vol. 3, 2022, pp.83-100 https://doi.org/10.37868/dss.v3.id199 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 83 using data envelopment analysis (dea) for measuring efficiency in the defense sector ivan okromtchedlishvili1* 1 phd student, business administration, faculty of business and technology, international black sea university, tbilisi, georgia *corresponding author e-mail: iokro@yahoo.com received: oct. 3, 2022 revised: nov. 15, 2022 accepted: nov. 17, 2022 online: nov. 21, 2022 abstract the way to improve the efficiency and effectiveness of public spending, which is a top priority for any government in any country, implies the introduction of performance-based budgeting (pbb). one of the more advanced governmentwide performance budgeting systems that uses performance information systematically in the preparation of the government budget is program budgeting. it is important to keep in mind that without systematic development and use of program performance information and adequate and effective performance indicators, program budgeting in the defense sector does not make sense as a tool to improve the efficiency and effectiveness of the defense resource management process. only by defining and tracking success can it be known if the defense organizations and units perform efficiently and effectively. in this article, data envelopment analysis (dea) was considered an instrument that can be used to measure, evaluate, and analyze the efficiency of the state and government as a whole, as well as commercial and non-profit organizations, including military units. it can be used as an instrument to hold managers accountable for their performance, which is critical to effective pbb. in this article, dea has been applied to nato members and some eastern europe post-soviet aspirant and partner countries (ukraine, georgia and moldova) to understand how efficient each country is at achieving its military power. in order to demonstrate the feasibility of using dea to examine the efficiency of the infantry battalions of the infantry brigades under the eastern and western commands of the georgian defense forces (gdf), an illustrative analysis of the efficiency of the aforementioned units was carried out using fictitious data. © the author 2022. published by arda. keywords: program budgeting; performance; efficiency; effectiveness; data envelopment analysis. 1. introduction the introduction of performance-based budgeting (pbb) is a way to improve the efficiency and effectiveness of public spending, which is a top priority for any government in any country. this approach implies focusing rather on the results of spending and the achievement of policy objectives than on the management of inputs and provides budget decision-makers with greater discretion in the use of resources and in deciding the input mix. however, simultaneously, increased flexibility, and weakened central controls are counterbalanced by dss vol. 3, 2022, pp.83-100 84 stronger internal controls and oversight and accountability mechanisms to hold managers accountable for the results of their performance. pbb implies the systematic use of performance information in the budget process to make results a central determinant of budget funding decisions, and thereby make budgeting a powerful instrument for maximizing government’s efficiency and effectiveness. program budgeting is one of the most advanced nationwide performance budgeting systems that systematically uses performance information in the preparation of the state budget where expenditures are classified into groups of similar activities or projects (i.e. programs) with common outputs and outcomes. the main differences between the traditional line-item budget method and the program budget method are presented in the table 1. table 1. the main differences between the traditional line-item budget method and the program budget method [26] budget method characteristics primary organization feature budget focus line-item expenditure budget expenditure by commodity or resource purchased resources purchased control of resources program budget expenditure related to public goals cost data across organizational lines achievements (products or outputs) planning defense is an important part of the public sector, and its organizations consume large amounts of public resources. improving the efficiency and effectiveness of managing defense funds and ensuring a successful defense budgeting process implies introducing the performance-based (program) budgeting approach in the defense sector as well. the systematic development and use of program performance information is critical to achieving a good defense program budget. without adequate and effective performance indicators and their application to assess the performance of program managers, program budgeting in the defense sector does not make sense as a tool to improve the efficiency and effectiveness of the defense resource management process; this will only make it easier and simpler for the ministry to allocate and use budgetary resources by loosening line item controls, without obtaining the core benefits of program budgeting. van dooren et al. [1, p. 20] argue that “performance can be defined as outputs and outcomes.” the principal tool of program budgeting identified by robinson [2], along with “budgetary expenditure classification in terms of outcome/output groups (“programs”), is “the systematic gathering of performance information (through indicators, evaluation, etc.) to inform decisions about budgetary priorities between competing programs.” performance-based budgets require information on inputs (measured in monetary terms), outputs (units of output), efficiency and productivity data (cost per activity), and effectiveness information (level of goal achievement) [3]. in the case of the defense ministry, performance information (outputs, outcomes, and indicators) and its systematic development and use are critical to achieving a good defense program budget and an effective resource allocation. the existence of a clear linkage between resource allocation and desired/produced outputs and outcomes is crucial for defense decision-makers to provide them with the ability to compare the costs and benefits of alternative spending options and choose the most effective ones, as well as monitor and control performance. the old management adage “you can’t manage what you can’t measure” applies to the defense sector as well. without defining and tracking success, it is impossible to know if the defense organizations and units are successful. dss vol. 3, 2022, pp.83-100 85 when considering the defense sector's activities, two aspects can be distinguished. the first concerns the products/services (outputs) produced by defense entities through the use of resources and is related to efficiency ("doing things right"). the second aspect, which concerns the impact of the produced products or services (outputs) on the objectives set for defense, is related to effectiveness (“doing the right things”). as webb & angelis [24] noted, “to measure efficiency, we must understand the relationship between the cost of inputs and the amount of outputs […] to measure effectiveness, we must understand the relationship between the organization’s goals and objectives [or outcomes] and its outputs […].” in order to do the right things (or to achieve effectiveness), defense policy-makers and decision-makers have to choose and develop the right mix of subprogram (intermediate) outputs to produce the final output (military capability) of the defense program, maximizing their preference value for outcomes, while subprogram managers have to do things right when responsible for producing outputs efficiently [13]. data envelopment analysis (dea) can be seen as a tool to measure and evaluate the effectiveness and efficiency of the state and government as a whole, as well as non-profit and commercial organizations, units and subunits (including defense organizations and units). it can be used as an instrument to hold managers accountable for their performance which is critical to effective pbb. the results of the dea analysis, in the form of potential improvements, offer management (commanders) opportunities to explore in search of higher performance. the process includes identifying the main sources of inefficiency, as well as those units that can become a benchmark for others. in this study, dea has been applied to nato members and some eastern europe post-soviet aspirant and partner countries (ukraine, georgia and moldova) to understand how efficient each country is at achieving its military power. the efficiency of the decision-making units was measured with a ccr model. as for the georgian defense forces (gdf) units, in particular the infantry battalions of the infantry brigades under the eastern and western commands, there are significant limitations in conducting such research due to the secrecy of detailed information, especially regarding the output of the defense program, namely, the military capability and its indicators – readiness levels of units. in addition, due to the peculiarities of the current defense program structure, obtaining accurate cost information, such as detailed information on the cost per battalion for any given period, should be very problematic. therefore, in order to demonstrate the feasibility of using dea to examine the efficiency of operational units, an illustrative analysis of the efficiency of the aforementioned infantry battalions was carried out using fictitious data. 2. data envelopment analysis (dea) 2.1 the use of the dea in measuring performance an excellent mathematical programming tool that can be used to measure, evaluate, and analyze performance is data envelopment analysis (dea), which has been used to evaluate the performance of many different types of organizations, including government, not-for-profit and commercial units and subunits since it was first introduced in the late 1970s. as a comparative performance measurement tool, dea is aimed at facilitating “a program to improve performance, not to provide a simple grading of service providers” [4]. according to avkiran, dea is a nonparametric method that provides a comparative ratio of weighted outputs to inputs for each decision-making unit (dmu), i.e., a relative efficiency score, which is usually reported as a number from 0 to 100% or 0 to 1. a unit scoring less than 100% is considered inefficient compared to other units in the sample [5]. efficiency can be defined as a "degree to which the observed use of resources to produce outputs of a given quality matches the optimal use of resources to produce outputs of a given quality" [4]. sherman defines efficiency as "the ability to produce products or services with the minimum level of resources required" [6]. farrell recognized the importance of measuring the extent to which outputs could be increased through higher dss vol. 3, 2022, pp.83-100 86 efficiency without the use of additional inputs [7]. the pareto optimality condition for efficient production states that a dmu is inefficient if the output can be increased without increasing any input and without decreasing any other output; likewise, a dmu is inefficient if the input can be decreased without decreasing any output and without increasing any other input [8]. dea measures the efficiency of decision-making units (dmus) using linear programming techniques, envelops observed input-output vectors as tightly as possible and allows to consider multiple input-output vectors at the same time without any assumptions on data distribution. in each case, efficiency is measured by proportional changes in inputs or outputs. according to ji and lee, “a dea model can be subdivided into an input-oriented model, which minimizes inputs while satisfying at least the given output levels, and an outputoriented model, which maximizes outputs without requiring more of any observed input values” [9]. the original charnes, cooper, and rhodes (ccr) dea model utilizes linear programming to produce an efficiency measure for a dmu, requiring only that the dmus convert similar inputs to similar outputs and that these can be quantified. the logic of the model implies, first, defining the underlying premise that efficiency is the sum of weighted outputs over the sum of weighted inputs [10]. the dea model for the kth dmu can be formulated as follows: t ∑ uryrk max ek = r = 1 m ∑ vixik i = 1 t ∑ uryrj s.t. r = 1 ≤ 1 j = 1,……n m ∑ vixij i = 1 ur ≥ 0 r = 1,…….t vi ≥ 0 i = 1,…….m, where: objective function ek = the efficiency index of the kth dmu; parameters yrj = the amount of the rth output for the jth dmu; xij = the amount of the ith input for the jth dmu; t = the number of outputs; m = the number of inputs; and n = the number of dmus decision variables ur = the weight assigned to the rth output; and vi = the weight assigned to the ith input [11]. generally, in the defense sector area, dea efficiency and productivity studies have focused on various support functions such as maintenance and recruitment, as well as operational units, the core area of defense (see table 2). dss vol. 3, 2022, pp.83-100 87 table 2. bibliography of dea in the military [12] paper field inputs outputs observa tions lewin and morey (1981) recruitment 10 2 43 charnes et al. (1985) maintenance 8 4 42 bowlin (1987) maintenance 3 4 21 bowlin (1989) accounting and finance 1 5 18 ali et al. (1989)* recruitment n/a n/a n/a roll et al. (1989) maintenance 3 2 10-35 clarke (1992) maintenance 4 2 17 ozcan and bannick (1994) hospitals 6 2 23 bowlin (2004) civil reserve air fleet 4 7 37-111 brockett et al. (2004) recruitment 1 10 n/a sun (2004) maintenance 6 5 30 farris et al. (2006) engineering design projects 4 1 15 lu (2011) kalin (2021) hanson (2012) hanson (2019) outlets logistics operational units combat units 4 4 3 3 (1) 2 1 1 1 (1) 31 34 11 12 *paper not available. hanson conducted interesting research that examined the productivity and efficiency of the core area of the norwegian armed forces, operational units, using data envelopment analysis (dea). a model has been developed to analyze the productivity and efficiency by dea for the operational units of the armed forces. as hanson noted, “by aggregating activity standards and quality measures the model enables a meaningful and measurable expression for the output of an operational unit” [12, p. 25]. in another study, hanson used a scenario-based planning approach to develop an effectiveness measurement model for situations where traditional methods such as two-stage regression fail due to long time lags and lack of variation in the variables. according to hanson, “from a sample of 12 combat units in the norwegian armed forces, producing different outputs, [it was found] that inefficiencies in output mix can explain most of the changes in overall effectiveness over a four-year period of time” [13]. 2.2 examining the efficiency of nato members and some partner countries in achieving military power by using dea dea has been applied to nato members and some eastern europe post-soviet aspirant and partner countries (ukraine, georgia and moldova) to understand how efficient each country is at achieving its military power. the efficiency of the decision-making units was measured with a ccr model. 2.2.1 specification of data and variables a total of 31 dmus were selected for the study. these dmus focused on nato members and some eastern europe post-soviet aspirant and partner countries (ukraine, georgia and moldova). the study was aimed at measuring how efficiently each country achieved its military power. four variables were retrieved from the open sources [28], [29], [30], [31]: two input variables defense expenditure, current prices and exchange rates us dollars for 2020; defense expenditure as a share of real gdp (%) for 2020; and two output variables military personnel for 2020; and military strength ranking for 2022 (reversed). dss vol. 3, 2022, pp.83-100 88 defense expenditure refers to all current and capital spending on the armed forces of a state and in theory, the higher the level of defense expenditure, the better the military power of the state. the commitment made in 2014 by members of the north atlantic treaty organization (nato) to increase their defense expenditure as a share of real gdp to 2 % by 2024 is still the subject of debate about military spending in nato [25]. in my recent article, i proposed to define the main output of a defense program as “military capability as a comprehensive force structure consisting of its constituent force elements/capabilities […] with an integrated set of aspects categorized as doctrine, organization, training, materiel, leadership development, personnel, and facilities, and with an appropriate readiness level assessed at a concrete time” [23]. therefore, in this case, it is crucial that military personnel be considered as an integral part of military capability (combat-ready forces), i.e., the “production” of military personnel implies the simultaneous development of the military capability as a whole (across the entire dotmlpf spectrum). in principle, the gfp rating (military strength ranking) is a kind of indicator of the performance of the defense organization of a state, and an improved position in the ranking is evidence of increased efficiency and effectiveness of the defense programs. for this study, the reverse military power index (global firepower, 2022) was used, so it was assumed that the higher the military power index, the better the country. at the initial measure, the lower the military index, the better. 2.2.2 dea model and results the dea analysis was carried out using dea-solver-pro 5.0 software [22] developed by w.w. cooper, l.m. seiford and k. tone. this study performed a ccr input-oriented dea model, and the main focus was to see how efficient each country was at producing military capability and achieving its military power index, given its resources or inputs. table 3 and table 4 below show the results of running the model. table 3. dea test results rank dmu score rank dmu score 1 moldova 1 17 netherlands 0,57707535 1 united states 1 18 bulgaria 0,570603056 1 spain 1 19 poland 0,569492872 1 türkiye 1 20 hungary 0,55453459 5 czech republic 0,971773347 21 united kingdom 0,548049942 6 ukraine 0,932569009 22 belgium 0,533707754 7 italy 0,909221694 23 croatia 0,528911822 8 portugal 0,8447062 24 slovenia 0,5158751 9 georgia 0,792712503 25 slovak republic 0,476957309 10 france 0,697923222 26 albania 0,376089889 11 romania 0,665795625 27 north macedonia 0,368317769 12 germany 0,662166375 28 lithuania 0,28768714 13 greece 0,634367881 29 latvia 0,20825904 14 norway 0,631334284 30 montenegro 0,197800912 15 canada 0,610115983 31 estonia 0,157514612 16 denmark 0,578313316 dss vol. 3, 2022, pp.83-100 89 table 4. projections by the ccr model no dmu score i/o data projection difference % 1 united states 1 defense expenditure 7,84952e+11 7,84952e+11 0 0,00% defense expenditure as a share of real gdp (%) 3,72 3,72 0 0,00% military personnel 1346000 1346000 0 0,00% military strength ranking (reversed) 35,8958 35,8958 0 0,00% 2 france 0,697923222 defense expenditure 52727000000 36799397750 -15927602250 -30,21% defense expenditure as a share of real gdp (%) 2,03 1,416784142 -0,613215858 -30,21% military personnel 208000 208000 0 0,00% military strength ranking (reversed) 5,7275 5,7275 0 0,00% 3 united kingdom 0,548049942 defense expenditure 61925000000 33937992687 -27987007313 -45,20% defense expenditure as a share of real gdp (%) 2,29 1,255034368 -1,034965632 -45,20% military personnel 156200 175283,8318 19083,83183 12,22% military strength ranking (reversed) 5,2184 5,2184 0 0,00% 4 italy 0,909221694 defense expenditure 26071000000 23704318784 -2366681216 -9,08% defense expenditure as a share of real gdp (%) 1,38 1,254725938 -0,125274062 -9,08% military personnel 175500 175500 0 0,00% military strength ranking (reversed) 4,7871 4,7871 0 0,00% 5 türkiye 1 defense expenditure 13396000000 13396000000 0 0,00% defense expenditure as a share of real gdp (%) 1,86 1,86 0 0,00% military personnel 437200 437200 0 0,00% military strength ranking (reversed) 4,4351 4,4351 0 0,00% 6 germany 0,662166375 defense expenditure 58902000000 39002923817 -19899076183 -33,78% defense expenditure as a share of real gdp (%) 1,55 1,026357881 -0,523642119 -33,78% military personnel 186900 186900 0 0,00% military strength ranking (reversed) 4,3067 4,3067 0 0,00% 7 spain 1 defense expenditure 12828000000 12828000000 0 0,00% defense expenditure as a share of real gdp (%) 1 1 0 0,00% military personnel 122500 122500 0 0,00% military strength ranking (reversed) 3,7337 3,7337 0 0,00% 8 ukraine 0,932569009 defense expenditure 5924000000 5524538808 -399461191,8 -6,74% dss vol. 3, 2022, pp.83-100 90 defense expenditure as a share of real gdp (%) 4,1 3,823532936 -0,276467064 -6,74% military personnel 209000 209000 0 0,00% military strength ranking (reversed) 3,4016 6,261898544 2,860298544 84,09% 9 canada 0,610115983 defense expenditure 23595000000 14395686628 -9199313372 -38,99% defense expenditure as a share of real gdp (%) 1,44 0,878567016 -0,561432984 -38,99% military personnel 71000 111398,8073 40398,80729 56,90% military strength ranking (reversed) 3,3736 3,3736 0 0,00% 10 poland 0,569492872 defense expenditure 13590000000 7739408124 -5850591876 -43,05% defense expenditure as a share of real gdp (%) 2,28 1,298443747 -0,981556253 -43,05% military personnel 120000 120000 0 0,00% military strength ranking (reversed) 3,1759 3,1759 0 0,00% 11 greece 0,634367881 defense expenditure 5019000000 3183892393 -1835107607 -36,56% defense expenditure as a share of real gdp (%) 2,65 1,681074884 -0,968925116 -36,56% military personnel 107600 107600 0 0,00% military strength ranking (reversed) 2,8681 2,8681 0 0,00% 12 norway 0,631334284 defense expenditure 7272000000 4591062910 -2680937090 -36,87% defense expenditure as a share of real gdp (%) 2,01 1,26898191 -0,74101809 -36,87% military personnel 20800 54698,49719 33898,49719 162,97 % military strength ranking (reversed) 2,6527 2,6527 0 0,00% 13 netherlands 0,57707535 defense expenditure 13125000000 7574113967 -5550886033 -42,29% defense expenditure as a share of real gdp (%) 1,47 0,848300764 -0,621699236 -42,29% military personnel 40000 75401,12632 35401,12632 88,50% military strength ranking (reversed) 2,5771 2,5771 0 0,00% 14 romania 0,665795625 defense expenditure 5051000000 3362933704 -1688066296 -33,42% defense expenditure as a share of real gdp (%) 2,03 1,351565119 -0,678434881 -33,42% military personnel 66400 66400 0 0,00% military strength ranking (reversed) 2,5072 2,5072 0 0,00% 15 czech republic 0,971773347 defense expenditure 3201000000 3110646484 -90353515,56 -2,82% defense expenditure as a share of real gdp (%) 1,31 1,273023085 -3,70e-02 -2,82% military personnel 26800 41984,69203 15184,69203 56,66% military strength ranking (reversed) 2,3944 2,3944 0 0,00% 16 portugal 0,8447062 dss vol. 3, 2022, pp.83-100 91 defense expenditure 3306000000 2792598697 -513401303 -15,53% defense expenditure as a share of real gdp (%) 1,43 1,207929866 -0,222070134 -15,53% military personnel 28700 38467,306 9767,306 34,03% military strength ranking (reversed) 2,2436 2,2436 0 0,00% 17 hungary 0,55453459 defense expenditure 2770000000 1536060814 -1233939186 -44,55% defense expenditure as a share of real gdp (%) 1,79 0,992616916 -0,797383084 -44,55% military personnel 22700 25069,63378 2369,63378 10,44% military strength ranking (reversed) 1,7083 1,7083 0 0,00% 18 denmark 0,578313316 defense expenditure 4979000000 2879422001 -2099577999 -42,17% defense expenditure as a share of real gdp (%) 1,4 0,809638643 -0,590361357 -42,17% military personnel 18100 34469,74292 16369,74292 90,44% military strength ranking (reversed) 1,6836 1,6836 0 0,00% 19 slovak republic 0,476957309 defense expenditure 2050000000 977762482,9 -1072237517 -52,30% defense expenditure as a share of real gdp (%) 1,96 0,934836325 -1,025163675 -52,30% military personnel 12900 19568,30014 6668,300138 51,69% military strength ranking (reversed) 1,5252 1,5252 0 0,00% 20 croatia 0,528911822 defense expenditure 1031000000 545308088,2 -485691911,8 -47,11% defense expenditure as a share of real gdp (%) 1,8 0,952041279 -0,847958721 -47,11% military personnel 15200 16045,33197 845,3319659 5,56% military strength ranking (reversed) 1,4729 1,4729 0 0,00% 21 bulgaria 0,570603056 defense expenditure 1075000000 613398285,7 -461601714,3 -42,94% defense expenditure as a share of real gdp (%) 1,55 0,884434738 -0,665565262 -42,94% military personnel 25600 25600 0 0,00% military strength ranking (reversed) 1,3664 1,3664 0 0,00% 22 belgium 0,533707754 defense expenditure 5427000000 2896431982 -2530568018 -46,63% defense expenditure as a share of real gdp (%) 1,05 0,560393142 -0,489606858 -46,63% military personnel 25200 31646,37661 6446,376605 25,58% military strength ranking (reversed) 1,3265 1,3265 0 0,00% 23 lithuania 0,28768714 defense expenditure 1176000000 338320076,6 -837679923,4 -71,23% defense expenditure as a share of real gdp (%) 2,11 0,607019865 -1,502980135 -71,23% military personnel 16300 16300 0 0,00% military strength ranking (reversed) 0,8633 0,924254558 6,10e-02 7,06% 24 slovenia 0,5158751 dss vol. 3, 2022, pp.83-100 92 defense expenditure 568000000 293017056,6 -274982943,4 -48,41% defense expenditure as a share of real gdp (%) 1,08 0,557145108 -0,522854892 -48,41% military personnel 7000 9164,882239 2164,882239 30,93% military strength ranking (reversed) 0,8573 0,8573 0 0,00% 25 georgia 0,792712503 defense expenditure 292000000 231472050,9 -60527949,13 -20,73% defense expenditure as a share of real gdp (%) 1,8 1,426882505 -0,373117495 -20,73% military personnel 20650 20650 0 0,00% military strength ranking (reversed) 0,8169 2,09945964 1,28255964 157,00 % 26 latvia 0,20825904 defense expenditure 743000000 154736466,7 -588263533,3 -79,17% defense expenditure as a share of real gdp (%) 2,22 0,462335069 -1,757664931 -79,17% military personnel 7000 7000 0 0,00% military strength ranking (reversed) 0,6953 0,6953 0 0,00% 27 moldova 1 defense expenditure 44500000 44500000 0 0,00% defense expenditure as a share of real gdp (%) 0,4 0,4 0 0,00% military personnel 5150 5150 0 0,00% military strength ranking (reversed) 0,5859 0,5859 0 0,00% 28 estonia 0,157514612 defense expenditure 719000000 113253006,3 -605746993,7 -84,25% defense expenditure as a share of real gdp (%) 2,32 0,365433901 -1,954566099 -84,25% military personnel 6600 6600 0 0,00% military strength ranking (reversed) 0,5455 0,5455 0 0,00% 29 albania 0,376089889 defense expenditure 188000000 70704899,2 -117295100,8 -62,39% defense expenditure as a share of real gdp (%) 1,27 0,47763416 -0,79236584 -62,39% military personnel 6700 6700 0 0,00% military strength ranking (reversed) 0,4276 0,701893273 0,274293273 64,15% 30 montenegro 0,197800912 defense expenditure 83000000 16417475,73 -66582524,27 -80,22% defense expenditure as a share of real gdp (%) 1,73 0,147572816 -1,582427184 -91,47% military personnel 1900 1900 0 0,00% military strength ranking (reversed) 0,1695 0,216157282 0,046657282 27,53% 31 north macedonia 0,368317769 defense expenditure 154000000 56720936,47 -97279063,53 -63,17% defense expenditure as a share of real gdp (%) 1,25 0,460397212 -0,789602788 -63,17% military personnel 6100 6100 0 0,00% military strength ranking (reversed) 0,1283 0,67508041 0,54678041 426,1% dss vol. 3, 2022, pp.83-100 93 2.2.3 summary and recommendations the study showed that some states were efficient at producing their military capability and achieving the military power index utilizing the inputs provided, while others needed to improve. according to the test results, 4 out of the 31 countries (united states, spain, türkiye and moldova) outputted 1.00 or 100 percent efficiency across the dea model and can be used as benchmarks. the ccr input-oriented model we applied measures technical efficiency, or how resources are used during the production/delivery of an output (doing the things right). since the scores of other states were below 1.00 or 100 percent, this means that the ministries of defense should look for ways to utilize the allocated budgetary resources more efficiently to achieve higher results and improve positions in the military strength ranking. 2.3 a sample dea model for measuring the efficiency of the gdf infantry battalions in the case of the georgian defense forces (gdf), the dea can be used, for example, to examine the efficiency of operational units, particularly the infantry battalions of the infantry brigades under the eastern and western commands, on delivery of readiness. however, a significant limitation in conducting such research is the secrecy of detailed information, especially regarding the output of the defense program, namely, the military capability and its indicators – readiness levels of units. also, due to the peculiarities of the current defense program structure, it should be quite problematic to obtain accurate information regarding the inputs, for example, detailed costs per battalion for any particular period. consequently, in order to demonstrate the possibility of using dea for the above purposes, an illustrative analysis of the efficiency of battalions was carried out using fictitious data. figure 1. units, equipment, and personnel in an army infantry brigade combat team, excluding support battalion [17] dss vol. 3, 2022, pp.83-100 94 according to strategic defense review (sdr) 2021-2025 [14], the gdf future force structure, along with other military units, includes four infantry brigades under the eastern and western commands. due to the unavailability of relevant information regarding the structure of brigades of the gdf from open sources, data on the structure of brigades of the us army were used as an example. infantry brigade combat teams (ibcts) constitute the army’s “light”, primarily foot-mobile ground forces that can move by foot, vehicle, or air (either air landed or by helicopter) [15]. according to the army’s field manual (fm) 3-96, the ibcts are employed as follows: “the role of the ibct is to close with the enemy by means of fire and movement to destroy or capture enemy forces, or to repel enemy attacks by fire, close combat, and counterattack to control land areas, including populations and resources” [16]. ibcts are relatively independent tactical formations that are designed to include approximately 4,400 personnel [17]. as can be seen from figure 1, there are three infantry battalions in the ibct. since there are four infantry brigades in the gdf future force structure, it can be assumed that there will be a total of 12 infantry battalions that will be treated as decision making units (dmus) in our sample dea model. two input variables can be defined for the use of personnel and equipment: (1) personnel costs pay and benefits for military personnel, compensation for civilian employees, health care costs, and travel expenses for military and civilian personnel; and (2) material costs daily expenses of operating a unit, such as equipment maintenance, training, support contractors, and so on. readiness indicators by category can be used as outputs: personnel (p-level), equipment availability (s-level), equipment readiness (r-level) and training (tlevel) (see figure 2). figure 2. data model for the dea it should be mentioned that according to avkiran, “there are some rules of thumb on the number of inputs and outputs to select and their relation to the number of dmus” [5, p. 115]. boussofiane, dyson and thanassoulis argue that to obtain good discriminatory power out of the ccr and bcc models, the lower bound on the number of dmus must be a multiple of the number of inputs and the number of outputs. for example, if there are 2 inputs and 4 outputs, the minimum total number of dmus must be 8 for some discriminatory power to dss vol. 3, 2022, pp.83-100 95 exist in the model [18]. golany and roll propose a rule of thumb that the number of units should be at least twice the number of inputs and outputs under consideration [19]. bowlin mentions the need to have three times as many dmus as there are input and output variables [20]. according to dyson et al., a total of two times the product of the number of input and output variables is recommended [21]. for example, for a 3input, 4-output model, golany and roll recommend 14 dmus, while bowlin recommends 21 dmus. in any case, these figures should probably be used as the minimum for baseline performance models. as can be seen, the variants of dmus, inputs and outputs proposed in our example basically meet the above requirements. table 5 below shows the fictitious data for conducting the dea. table 5. fictitious data for conducting the dea dmu name input 1 personnel costs gel input 2 material costs gel output 1 p-level (%) output 2 s-level (%) output 3 r-level (%) output 4 t-level (%) 1st infantry battalion 10 800 000 5 000 000 85 91 70 85 2nd infantry battalion 10 200 000 5 500 000 75 82 75 85 3rd infantry battalion 11 760 000 6 000 000 88 74 96 87 4th infantry battalion 11 160 000 7 000 000 74 96 84 78 5th infantry battalion 10 680 000 6 500 000 96 97 99 95 6th infantry battalion 10 920 000 5 850 000 81 75 82 76 7th infantry battalion 10 788 000 5 100 000 68 85 78 82 8th infantry battalion 11 520 000 5 350 000 92 86 91 95 9th infantry battalion 11 040 000 5 120 000 77 88 99 87 10th infantry battalion 10 560 000 4 950 000 85 91 75 81 11th infantry battalion 10 320 000 6 200 000 86 69 85 73 12th infantry battalion 11 568 000 6 850 000 91 92 94 93 the exemplifying analysis was carried out using dea-solver-pro 5.0 software [22]. as can be seen from the dea test results depicted in table 6 and 7, five of the twelve infantry battalions are efficient, while the rest show some inefficiency. table 6. dea test results rank dmu score 1 10th infantry battalion 1 1 1st infantry battalion 1 1 9th infantry battalion 1 1 8th infantry battalion 1 1 5th infantry battalion 1 6 2nd infantry battalion 0,970912603 7 7th infantry battalion 0,954380827 8 4th infantry battalion 0,947123379 9 3rd infantry battalion 0,939071369 10 11th infantry battalion 0,93254636 11 12th infantry battalion 0,911386993 12 6th infantry battalion 0,87500128 dss vol. 3, 2022, pp.83-100 96 table 7. projections by the ccr model no. dmu score i/o data projection difference % 1 1st infantry battalion 1 personnel costs gel 10800000 10800000 0 0,00% material costs gel 5000000 5000000 0 0,00% p-level (%) 85 85 0 0,00% s-level (%) 91 91 0 0,00% r-level (%) 70 70 0 0,00% t-level (%) 85 85 0 0,00% 2 2nd infantry battalion 0,970912603 personnel costs gel 10200000 9903308,547 -296691,4534 -2,91% material costs gel 5500000 5340019,314 -159980,6857 -2,91% p-level (%) 75 84,23988411 9,239884114 12,32% s-level (%) 82 82,23862868 0,238628682 0,29% r-level (%) 75 85,26924191 10,26924191 13,69% t-level (%) 85 85 0 0,00% 3 3rd infantry battalion 0,939071369 personnel costs gel 11760000 11043479,3 -716520,7003 -6,09% material costs gel 6000000 5634428,214 -365571,7859 -6,09% p-level (%) 88 88 0 0,00% s-level (%) 74 90,00404513 16,00404513 21,63% r-level (%) 96 96 0 0,00% t-level (%) 87 92,00663008 5,006630078 5,75% 4 4th infantry battalion 0,947123379 personnel costs gel 11160000 10569896,91 -590103,0928 -5,29% material costs gel 7000000 6432989,691 -567010,3093 -8,10% p-level (%) 74 95,01030928 21,01030928 28,39% s-level (%) 96 96 0 0,00% r-level (%) 84 97,97938144 13,97938144 16,64% t-level (%) 78 94,02061856 16,02061856 20,54% 5 5th infantry battalion 1 personnel costs gel 10680000 10680000 0 0,00% material costs gel 6500000 6500000 0 0,00% p-level (%) 96 96 0 0,00% s-level (%) 97 97 0 0,00% r-level (%) 99 99 0 0,00% t-level (%) 95 95 0 0,00% 6 6th infantry battalion 0,87500128 personnel costs gel 10920000 9555013,98 -1364986,02 -12,50% material costs gel 5850000 5118757,489 -731242,5106 -12,50% p-level (%) 81 81 0 0,00% s-level (%) 75 78,99387085 3,993870847 5,33% r-level (%) 82 82 0 0,00% t-level (%) 76 81,84403062 5,84403062 7,69% dss vol. 3, 2022, pp.83-100 97 7 7th infantry battalion 0,954380827 personnel costs gel 10788000 10295860,37 -492139,6349 -4,56% material costs gel 5100000 4867342,219 -232657,7807 -4,56% p-level (%) 68 78,80442417 10,80442417 15,89% s-level (%) 85 85 0 0,00% r-level (%) 78 78 0 0,00% t-level (%) 82 82 0 0,00% 8 8th infantry battalion 1 personnel costs gel 11520000 11520000 0 0,00% material costs gel 5350000 5350000 0 0,00% p-level (%) 92 92 0 0,00% s-level (%) 86 86 0 0,00% r-level (%) 91 91 0 0,00% t-level (%) 95 95 0 0,00% 9 9th infantry battalion 1 personnel costs gel 11040000 11040000 0 0,00% material costs gel 5120000 5120000 0 0,00% p-level (%) 77 77 0 0,00% s-level (%) 88 88 0 0,00% r-level (%) 99 99 0 0,00% t-level (%) 87 87 0 0,00% 10 10th infantry battalion 1 personnel costs gel 10560000 10560000 0 0,00% material costs gel 4950000 4950000 0 0,00% p-level (%) 85 85 0 0,00% s-level (%) 91 91 0 0,00% r-level (%) 75 75 0 0,00% t-level (%) 81 81 0 0,00% 11 11th infantry battalion 0,93254636 personnel costs gel 10320000 9623878,44 -696121,5601 -6,75% material costs gel 6200000 5781787,435 -418212,5652 -6,75% p-level (%) 86 86 0 0,00% s-level (%) 69 87,15708111 18,15708111 26,31% r-level (%) 85 88,04103148 3,041031479 3,58% t-level (%) 73 84,94507688 11,94507688 16,36% 12 12th infantry battalion 0,911386993 personnel costs gel 11568000 10542924,74 -1025075,26 -8,86% material costs gel 6850000 6243000,905 -606999,0952 -8,86% p-level (%) 91 93,56101001 2,561010012 2,81% s-level (%) 92 93,80856701 1,808567007 1,97% r-level (%) 94 96,07991476 2,079914761 2,21% t-level (%) 93 93 0 0,00% sherman [27] argues that the dea is best used as a tool that can focus the attention of managers. in the infantry battalions example above, potential improvements suggest opportunities for managers (commanders) dss vol. 3, 2022, pp.83-100 98 to explore in search of higher performance. the process includes identifying the main sources of inefficiency as well as those units that can become reference dmus for others. 3. conclusions the way to improve the efficiency and effectiveness of public spending, which is a top priority for any government in any country, implies the introduction of performance-based budgeting (pbb). program budgeting is one of the most advanced government-wide performance budgeting systems that systematically uses performance information in the preparation of the state budget where expenditures are classified into groups of similar activities or projects (i.e., programs) with common outputs and outcomes. it is important to keep in mind that without systematic development and use of program performance information and adequate and effective performance indicators, program budgeting in the defense sector does not make sense as a tool to improve the efficiency and effectiveness of the defense resource management process. only by defining and tracking success can it be known if the defense organizations and units perform efficiently and effectively. in this article, dea was considered an excellent mathematical programming and a powerful management tool that can be used to measure, evaluate, and analyze the efficiency of the state and government as a whole, as well as commercial and non-profit organizations, including military units. dea can be applied as an instrument to hold managers at all levels accountable for their performance which is critical to effective performance-based budgeting (pbb). in this study, data envelopment analysis (dea) has been applied to nato members and some eastern europe post-soviet aspirant and partner countries (ukraine, georgia and moldova) to understand how efficient each country is at achieving its military power. the efficiency of the decision-making units was measured with a ccr model. due to the secrecy and peculiarities of the current defense program structure, there are significant limitations in obtaining detailed information on the main output of the defense, namely, the military capability and its indicators – readiness levels of units and accurate cost information, such as detailed information on the cost per battalion for any given period. therefore, in order to demonstrate the feasibility of using dea to examine the efficiency of operational units, an illustrative analysis of the efficiency of the aforementioned infantry battalions was carried out using fictitious data. i believe that one of the main barriers to using dea as a valid tool for measuring and evaluating the performance of the gdf units is the current structure of the defense program. the introduction of the defense program structure proposed in my recent article [23], which will include the major force program developed on a force capabilities basis; the definition of capabilities embodied in a force element as the main output of the defense subprograms; and the identification of force (program) elements (e.g., departments, commands, brigades, and battalions) as cost centers, will facilitate the use of the dea and other statistical tools to measure and evaluate the performance of the gdf units and develop proposals for its improvement. a key precondition for the successful application of the dea and other statistical tools in measuring and evaluating performance in the ministry of defense is the development of effective computerized financial management information systems (fmis), including computerized accounting systems. one of the challenges for the ministry is to implement an effective management accounting system to provide managers (unit commanders) with timely, accurate, meaningful, and insightful information without which an effective decision-making process is impossible. well-organized accounting systems are the main original source of the best quality and ultimately the most reliable primary data for the life cycle costing to support decision-making process as well as performance measurement and evaluation. dss vol. 3, 2022, pp.83-100 99 it is also crucial to include the “readiness level” as an output indicator in the defense program structure of the georgian ministry of defense. the target readiness levels of the gdf units should also be specified in the defense program guidance (dpg) and other planning documents of the mod of georgia (in the secret part of the documents), as well as procurement objectives and descriptions of acceptable risk. defense program managers who are accountable for the resources provided must monitor the balance of inputs to readiness and the state of readiness achieved. disclaimer the views represented in this paper are those of the author and don’t reflect the official policy or position of the ministry of defense of georgia. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] w. van dooren, g. bouckaert, and j. halligan, performance management in the public sector, routledge, 2015, doi: 10.4324/9781315817590. [2] m. robinson, best practice in performance budgeting, discussion paper no. 124, queensland, 2002. https://tinyurl.com/5dh8eass [3] northern ireland assembly, methods of budgeting, research paper 06/10, 2010. https://www.focusintl.com/rbm150-0610.pdf [4] steering committee for the review of commonwealth/state service provision, data envelopment analysis: a technique for measuring the efficiency of government service delivery, canberra, 1997. https://tinyurl.com/29wau6h4 [5] n. avkiran, productivity analysis in the service sector with data envelopment analysis, queensland, 2006. http://dx.doi.org/10.2139/ssrn.2627576 [6] h. d. sherman, service organization productivity management, the society of management accountants of canada, 1988. [7] m. j. farrell, “the measurement of productive efficiency,” journal of the royal statistical society. series a (general), vol. 120, no. 3, pp. 253-290, 1957, doi: 10.2307/2343100. https://www.jstor.org/stable/2343100 [8] a. charnes, w.w. cooper, and e. rhodes, “evaluating program and managerial efficiency: an application of data envelopment analysis to program follow through,” management science, vol. 27, no. 6, pp. 668-697, 1981. https://www.jstor.org/stable/2631155 [9] y. ji and c. lee, “data envelopment analysis,” the stata journal, vol. 10, no. 2, pp. 267–280, 2010. https://www.stata-journal.com/article.html?article=st0193 [10] a. charnes, w.w. cooper, and e. rhodes, “measuring the efficiency of decision making units,” european journal of operational research, vol. 2, pp. 429-444, 1978. https://tinyurl.com/2enk5vvh [11] y. ji and c. lee, “data envelopment analysis,” 267–280; patricia shewell and stephen migiro, “data envelopment analysis in performance measurement: a critical analysis of the literature,” problems and perspectives in management, vol. 14, no. 3-3, pp. 705-713, 2016. https://tinyurl.com/bdhv84uz [12] t. hanson, efficiency and productivity in the operational units of the armed forces, university of oslo, department of economics, 2012. https://www.econstor.eu/handle/10419/90728. dss vol. 3, 2022, pp.83-100 100 [13] t. hanson, “estimating output mix effectiveness: an applied scenario approach for the armed forces,” omega: the international journal of management science, vol. 83, pp. 39-49, 2019. https://tinyurl.com/yc7xurbu [14] ministry of defense of georgia, strategic defense review (sdr) 2021-2025, 2021. https://tinyurl.com/ya6bbe3p [15] congressional research service, infantry brigade combat team (ibct) mobility, reconnaissance, and firepower programs, 2019. https://crsreports.congress.gov [16] department of the army, fm 3-96 brigade combat team, 2021. https://tinyurl.com/4tnejznm [17] congressional budget office, the u.s. military’s force structure: a primer, 2021. www.cbo.gov/publication/57088 [18] a. boussofiane, r.g. dyson, and e. thanassoulis, “applied data envelopment analysis,” european journal of operational research, vol. 52, no. 1, pp. 1-15, 1991. https://tinyurl.com/yc768f95 [19] b. golany and y. roll, “an application procedure for dea,” international journal of management science, vol. 17, no. 3, pp. 237-250, 1989. https://tinyurl.com/5dpafsny [20] w. f. bowlin, “measuring performance: an introduction to data envelopment analysis (dea),” journal of cost analysis, vol. 15, no. 2, pp. 3-27, 1998. https://tinyurl.com/6xnuardk [21] r.g. dyson, r. allen, a.s. camanho, v.v. podinovski, c.s. sarrico, and e.a. shale, “pitfalls and protocols in dea,” european journal of operational research, vol. 132, no. 2, pp. 245-259, 2001. https://tinyurl.com/5cjp8a25 [22] w.w. cooper, l.m. seiford and k. tone, user’s guide to dea-solver-pro (professional version 5.0), springer, 2005. 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balance 2021, routledge, 2021. https://tinyurl.com/2y3nz8ck [29] https://data.worldbank.org/ [30] https://www.globalfirepower.com/ [31] https://www.nato.int/cps/en/natohq/news_184844.htm microsoft word 8-14_222 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.8-14 https://doi.org/10.37868/dss.v4.id222 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 8 potential of natural fiber composite materials for bulletproof vest applications ilham rizqi aminudin1*, sovian aritonang2 1,2 the republic of indonesia defense university, faculty of defense technology, motion power technology, indonesia. *corresponding author e-mail: ilham.aminudin@tp.idu.ac.id received: jan. 7, 2023 revised: jan. 12, 2023 accepted: feb. 21, 2023 online: feb. 25, 2023 abstract the bulletproof vest material that is often used is a composite material. composites are a mixture of two or more material elements, with different mechanical properties, which aim to obtain new materials that have better mechanical properties than the constituent materials. one alternative mixture of materials in composite materials is to use natural fibers as a substitute for kevlar fibers. in indonesia, which has a tropical climate, natural fibers are very easy to obtain from various kinds of plants found in indonesia. along with the many plants obtained, a lot of waste is also produced because of this. so research was conducted on the utilization of the potential of natural fibers for alternative composites. with the experimental method, from the results of the experiment, the results obtained from the five natural fibers that have been discussed, namely pineapple leaf fiber, water hyacinth fiber, bark fiber, hemp fiber, and bamboo fiber, only pineapple leaf fiber has not met the national institute of justice (nij) standard, while the other four natural fibers have met the nij standard for bulletproof vests. © the author 2023. published by arda. keywords: natural fiber; composite for bulletproof vest; mechanical properties; ballistic test; composite alternatives 1. introduction one of the needs of indonesian national armed forces (tni) personnel in the battlefield in addition to weapons to fight, tni personnel also need personal protective equipment, one of the personal protective equipment that is often used on the battlefield is a bulletproof vest. inside the bulletproof vest, there is a material coating the body that aims to reduce the amount of kinetic energy generated due to projectile penetration [1]. the bulletproof vest material that is often used is a composite material. composites are a mixture of two or more material elements, with different mechanical properties, which aim to obtain new materials that have better mechanical properties than the constituent materials. mechanical properties that can be improved are strength, flexibility, and low density [2]. composites also have their advantages when compared to other alternative materials, such as being stronger, lighter, economical, and environmentally friendly [3]. one of the alternative mixture materials in composite materials is to use natural fibers as a substitute for kevlar fibers. in indonesia, which has a tropical climate, natural fibers are very easy to obtain from various kinds of plants found in indonesia. along with the many plants obtained, a lot of waste is also produced because of this. nisa's research [4] explained the potential to recycle natural materials for composite mixtures in body armor applications. from this research, it is known that various kinds of natural materials can be utilized as waste to be used as an alternative composite for bulletproof vest applications. dss vol. 4, 2023, pp.8-14 9 2. research method this research focuses on descriptive qualitative research collecting existing experimental results and concluding what is the best result to be applied to bulletproof vests, while the natural materials to be discussed include bamboo fiber, hemp fiber, bark fiber, water hyacinth fiber, pineapple leaf fiber. for mechanical testing the standard used is astm and in ballistic tests using the national institute of justice (nij) 0108.01 ballistic resistant protective materials and nij 0101.06 armor protection levels standards. table 1. nij standard ballistic protection [1,13] level nij standard test bullets bullets mass (g) velocity (m/s) i 0108.01 22 lrhv lead 2.6 320 0108.01 38 special rn lead 10.2 259 iia 0101.06 9mm fmj rn 8.0 373 0101.06 0.40 s & w fmj rn 11.7 352 ii 0101.06 9mm fmj rn 8.0 398 0101.06 0.357 magnum jsp 10.0 436 iiia 0101.06 0.357 sig fmj fn 8.1 448 0101.06 0.44 magnum sjhp 15.6 436 iii 0101.06 7.62mm nato fmj 9.6 847 iv 0101.06 0.30 calibre m2 ap 10.8 878 3. results and discussion results and discussion of the research that has been carried out, using experimental methods with mechanical tests and ballistic tests. 3.1 pineapple leaf fiber (plf) one of the plants that thrive in indonesia is pineapple fruit, the selling value of pineapple fruit in indonesia is also very good, besides that, pineapple leaf waste has no selling value, so it can be called waste. the use of pineapple leaves itself has been done, such as the use of pineapple leaf fibers for composite material mixtures. like the research conducted by rahmatullah, et al (2021) [5] in this study, particle composites composed of epoxy with reinforcement in the form of hollow glass microsphere (hgm) and pineapple leaf fibers were used. the same percentage of matrix volume ratio and fiber, namely pineapple fiber 10%, epoxy resin 74% and hgm 16%, using a size of 15x15x2cm3, with thickness variations of 10 mm, 15 mm, and 20 mm. with nij standard level iia testing standards for test ammunition of 9 mm fmj, nominal bullet mass of 8.0 g, minimum required bullet of velocity 365 m/s. table 2. mechanical properties of pineapple leaf fiber [6,15] properties tensile strength (mpa) elongation (%) young’s modulus(gpa) hardness (hb) pineapple leaf fiber 126.60 2.2 4.405 20.41 from the test results of the test specimens in figure 1 with thicknesses of 10 mm, 15 mm and 20 mm, the results show that the bullet can penetrate the specimen with penetration depth values of 58 mm, 10 mm and 4 mm, respectively. according to the nij 0101.06 standard, the bulletproof vest failure criteria seen from the penetration aspect should not exceed the thickness of the vest or should not penetrate the vest. it is concluded that pineapple leaf fiber still cannot meet the criteria to become an alternative material for bulletproof vests. dss vol. 4, 2023, pp.8-14 10 figure 1. ballistic testing results (a) 10mm thickness (b) 15mm thickness (c) 20mm thickness [5] 3.2 water hyacinth fiber (whf) water hyacinth is a difficult-to-control aquatic weed that can live in rivers, swamps, and lakes. one alternative to utilizing it is as a composite material. in hanafi’s research (2020) [3] water hyacinth is utilized as an alternative material for bulletproof vest composites. this research uses a volume fraction of 30% fiber, 70% polyester, and a mold with a size of 15 x 15 cm thickness of 10 mm. the ballistic test used a 4.5 mm caliber angina rifle with a shooting distance of 5 m. there are 2 variations used, namely specimen 1 unidirectional and layered fiber arrangement, and specimen 2 vertical and horizontal layered fiber arrangement. table 3. mechanical properties of water hyacinth fiber [7,14] properties tensile strength (mpa) elongation (%) young’s modulus (gpa) hardness (hb) water hyacinth fiber 11.4 40.2 0.443 133 figure 2. (a) vertical directional arrangement (b) vertical and horizontal multi-layered arrangement [3] dss vol. 4, 2023, pp.8-14 11 the results of ballistic testing on the test specimens, specimen 1 and specimen 2 have a panel condition that is not penetrated by bullets at a speed of 229.81 m/s at a distance of 5 m with a caliber of 4.5 mm. from these results, specimens 1 and 2 are included in the nij 0108.01 level i standard. 3.3 bark fiber similar to the previous salak is one of the fruits with high selling value in indonesia, along with the salak fronds that are produced from each harvest into waste that has no selling value. one way to overcome this is by utilizing it as an alternative composite material for bulletproof vests. as in kamal's research (2021) [8] this research uses volume fractions with specimen 1: 70% resin, 20% kevlar, 10% filler silicon carbide (sic), silicon carbide (sic) is a compound of silicon and carbon that when joined together forms an extremely hard ceramic that is widely used for applications that require high durability, such as car brakes, car clutches, and bulletproof vests, specimen 2: 70% resin, 10% filler (sic), 10% salak frond fiber, 10% kevlar, specimen 3: 70% resin, 10% filler (sic), 10% salak frond fiber, 10% kevlar and al 7075. for ballistic tests using nij standard 0101.06 level iia and ii with distances of 5 m, 10 m, 25 m, and 30 m, with a firing speed of 373 m/s at a distance of 25 m, and 398 m/s at a distance of 5 m. table 4. mechanical properties of bark fiber [8] properties tensile strength (mpa) elongation (%) young’s modulus (gpa) hardness (hb) bark fiber 21.46 0.12 0.198 19.64 figure 3. specimen ballistic testing [8] the results of ballistic testing of specimen 1 with a distance of 5 m and 10 m bullets penetrated the test specimen, while at a distance of 25 m and 30 m, the bullets fired did not penetrate the test specimen. it can be said that specimen 1 meets the nij level iia standard. for specimen 2 from all testing distances the bullet successfully penetrated the test specimen, it can be said that specimen 2 does not meet the nij level iia standard. as for specimen 3 at all distances the bullet did not penetrate the test specimen, so it can be said that specimen 3 meets the nij level iia and ii standards. it can be concluded that specimen 1: 70% resin, 10% filler silicon carbide (sic), and 20% kevlar, complies with standard nij level iia and specimen 3: 70% resin, 10% filler (sic), 10% salak frond fiber, 10% kevlar and al 7075, meets standard nij level iia and ii. 3.4 hemp fiber one of the basic ingredients of bulletproof vests is glass fiber. in indonesia glass fiber material is still obtained from abroad. to minimize imported materials to reduce costs and increase, one way to find materials to replace glass fiber with minimal costs but with the same function, one material that is alternative to glass fiber for bulletproof vests is hemp fiber. hemp fiber is the basic material for making paper and clothing. the advantage of jute fiber compared to glass fiber is that it is more environmentally friendly and affordable. like the research conducted by setyawan (2020) [10] which examined hemp fiber for bulletproof vests. the study used a mixture ratio of 70% epoxy and 30% jute fiber with 4 variations, namely specimen 1 woven, specimen 2 horizontal, specimen 3 random specimen 4 tilted 45o with a specimen size of 20 x 20 cm. for ballistic tests using the nij 0108.01 standard caliber 38, speed 259 m/s with a distance of 10 m. dss vol. 4, 2023, pp.8-14 12 table 5. mechanical properties of hemp fiber [9] properties tensile strength (mpa) elongation (%) young’s modulus (gpa) hardness (hb) hemp fiber 310-750 2-4 20-41 84.6 figure 4. (a) webbing specimen 1 (b) horizontal specimen 2 (c) random specimen 3 (d) sloping specimen 4 [10] figure 5. specimen after ballistic testing [10] the results of ballistic testing using the nij 0108.01 standard include bullet deformation and whether or not the specimen is penetrated when hit by a bullet. in ballistic testing of the 4 specimens, no bullets penetrated the specimen, with the best result being specimen 1 in the form of webbing. it can be concluded that hemp fiber meets the nij 0108.01 level i standard. 3.5 bamboo fiber the main material in making bulletproof vest material is steel with a high density, so the weight of the bulletproof material is high which causes users to be unable to move freely. composites are materials consisting of two or more elements that have good mechanical properties and low density, so they can be used as an alternative to steel for bulletproof materials. arman (2022) utilizes bamboo fiber as a bulletproof material with a mixed matrix of epoxy resin/hardener and the addition of 20ml ceramic granules, with a 200mm x 100mm x 10mm mold. for ballistic testing using nij standard 0101.06 level iia, with shooting distances of 2 m, 2.5 m, and 3 m. dss vol. 4, 2023, pp.8-14 13 table 6. mechanical properties of hemp fiber bamboo fiber [12] properties tensile strength (mpa) elongation (%) young’s modulus (gpa) hardness (hb) bamboo fiber 206.2 29,2% 13.1 33 figure 5. bamboo fiber specimen after ballistic testing (a) 2 m (b) 2,5 m (c) 3 m [11] from the ballistic test results, it can be seen in figure 5 that none of the bullets penetrated the test specimens, so it can be concluded that the test results have met the nij 01.01.06 standard regarding the depth of ballistic penetration of composite materials. 3.6 discussion from the results of the data that have been obtained from the studies that have been carried out, the five natural fibers used for alternative composites for bulletproof vest applications can be categorized as follows: table 7. classification of natural materials based on nij standard [13] properties velocity (m/s) nij level reference pineapple leaf fiber (plf) 365 rahmatullah, et al (2021) water hyacinth fiber (whf) 229.81 i hanafi, et al (2020) bark fiber 398 iia & ii kamal, et al (2021) hemp fiber 259 i setyawan, et al (2020) bamboo fiber 373 iia arman, et al (2022) 4. conclusions from the results of the research and discussion above, it can be concluded that the use of natural fibers for alternative composites has been widely carried out to minimize the waste produced, at the same time natural materials for alternative composites are cheaper and environmentally friendly. of the five natural fibers that have been discussed, namely pineapple leaf fiber, water hyacinth fiber, salak frond fiber, hemp fiber, and bamboo fiber, only pineapple leaf fiber has not met the nij standard, while the other four natural fibers have met the nij standard for bulletproof vest. so that it can be applied to composite materials for making bulletproof vests for indonesian national armed forces (tni) personnel. dss vol. 4, 2023, pp.8-14 14 declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] standard nij-0101.04, "armor protection levels", u.s. department of justice, national institute of justice, 2000. [2] a. risky, r. efendi, "initial study of bamboo fiber-reinforced composite material with epoxy resin/hardener matrix as bulletproof material", jurnal teknik mesin indonesia, 17.2. 87-92. 2022. [3] b. hanifi, q. iqbal, h. purwanto, i. syafa’at, "effect of variation in water hyacinth (eichhornia crassipes) fiber arrangement with polyester resin as an alternative composite material for bulletproof vest", majalah ilmiah momentum, 2020. [4] l. l. a. nisa, m. te. manawan, "study of the potential development of composite materials reinforced with natural materials to be applied as body armor" jurnal teknologi daya gerak 5.1, pp. 71-82, 2022. [5] g. rahmatullah, b. mutiara, j. rollastin, "experimental study of pineapple leaf fiber reinforced composite materials in ballistic testing", seminar nasional inovasi teknologi terapan, no. 01, 2021. [6] r. m. n. arib, "mechanical properties of pineapple leaf fibre reinforced polypropylene composites", materials & design, pp. 391-396, 2006. [7] m. asrofi, "mechanical properties of a water hyacinth nanofiber cellulose reinforced thermoplastic starch bionanocomposite: effect of ultrasonic vibration during processing", fibers, 2018. [8] k. r. armando, m. a. ghofur, "ballistic test analysis of salak frond fiber composite with epoxy resin and silicon carbide (sic) using vacuum bag method" prosiding seminar nasional sains teknologi dan inovasi indonesia (senastindo), vol. 3, 2021. [9] a. shahzad, "hemp fiber and its composites a review," journal of composite materials, 46 (8), pp. 973-986, 2012. [10]s. r. teguh, s. riyadi, "analysis of hemp fiber structure variation of epoxy matrix composite on ballistic and bending test strength", majalah ilmiah momentum, 16(2), 2020. [11]a. risky, r. efendi, "initial study of bamboo fiber-reinforced composite material with epoxy resin/hardener matrix as bulletproof material," jurnal teknik mesin indonesia 17(2), pp. 87-92, 2022. [12] z. li, c. p. liu, t. yu, "laminate of reformed bamboo and extruded fiber-reinforced cementitious plate", journal of materials in civil engineering, 14(5), pp. 359-365, 2002. [13] standard nij 0108.01, ballistic resistant protective materials, u.s. department of justice, national institute of justice, 1985. [14]n. h. nawal et al, "charpy impact behavior of water hyacinth fiber based polymer composite," journal of material science & manufacturing technology, 2(2), pp. 1-13, 2017. [15]h. sosiati, "characterization of the mechanical features of nanas fiber/epoxy composite with addition of brass fibers and mgo as an alternative material for motorcycle brake shamps," undergraduate thesis, universitas muhammadiyah yogyakarta, 2018. microsoft word 23-28_228 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.23-28 https://doi.org/10.37868/dss.v3.id228 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 23 indonesia's role in the g20 presidency during the conflict between russia and ukraine ria purwati1*, hikmat zakky almubaroq2, edy saptono3 1,2,3 republic of indonesia defense university, faculty of defense management, indonesia *corresponding author e-mail: riapurwa21@gmail.com received: jan. 13, 2023 revised: jan. 31, 2023 accepted: feb. 1, 2023 online: feb. 6, 2023 abstract indonesia was appointed as the g20 presidency holder at the 2020 riyadh summit and handed over from italy on october 31, 2021, in rome, italy. along with the g20 presidency activities in indonesia, the conflict between russia ukraine heated up again in early february 2022 after the russian fighter fleet attacked the ukrainian border, precisely in belarus. various impacts were felt by countries around russia-ukraine including indonesia. indonesia as the holder of the g20 presidency in 2022 must take a stand against russia invading ukraine. this paper uses qualitative research methods, data collection techniques in this paper are based on internet-based research. the indonesian government as the g20 presidency has also conducted political, legal, and security negotiations that not only talk about the issue of the war that occurred between russia and ukraine in early 2022 but also bring the main issue of the economy. indonesia's duty according to the constitution is to encourage that world issues can still be resolved in the g20 forum. indonesia's stance in realizing world peace is enshrined in the preamble of the 1945 constitution. in an effort to create world peace, indonesia is considered to still have to prioritize wise steps. © the author 2023. published by arda. keywords: presidency, g20, indonesia, russia, ukraine 1. introduction the global financial crisis in 2007 has created a negative impact on both developed and developing countries. the global financial crisis occurred due to a lack of international coordination that was responsive to the crisis and unaccountable financial sector regulations (excessive risk taking). the global financial crisis caused developed countries to experience a downturn in their financial sector and impacted the real sector, while developing countries were affected in the field of trade and foreign investment. so the idea of the g-20 leaders meeting group was formed to organize a g20 summit for the leaders or heads of state of the g20 group in washington dc on november 15, 2008 [1]. g20 members began coordinating joint action through an assessment process that identified common goals for the global economy, the policies needed to achieve them, and progress toward meeting those common goals. the fact that gdp per capita in g20 countries is on a lower growth path than before the global financial crisis is a major concern for the g20. nonetheless, employment levels have risen to almost pre-crisis levels. the g20 is a multilateral cooperation forum consisting of 19 major countries and the european union that have middle to high income classes, developing countries to developed countries. g20 members consist of countries from various regions in the world including the united states, canada, mexico, argentina, brazil, united kingdom, germany, italy, france, russia, south africa, saudi arabia, turkey, china, japan, south korea, india, indonesia, australia and the european union. the g20 has no permanent leader or chairman, while the presidency function is held by one of the members for one year [2]. dss vol. 4, 2023, pp.23-28 24 indonesia was confirmed as the g20 presidency holder at the 2020 riyadh summit and handed over from italy on october 31, 2021 in rome, italy. indonesia's g20 presidency officially begins on december 1, 2021 until the next presidency handover at the summit at the end of 2022. g20 indonesia consists of various meetings that will be held in several cities in indonesia. about 19 cities besides bali will be involved such as jakarta, bogor, semarang, solo, batam bintan, medan, yogyakarta, bandung, sorong, lombok, surabaya, labuan bajo, lake toba, manado, malang and others. the g20 presidency in 2022 was the first time for indonesia to join the g20 since the international forum was established in 1999. at that time, indonesia was recovering from the 1997-1998 economic crisis and was considered an emerging economy with enormous economic size and potential in the asian region. indonesia was the only asean and g20 member that played an important role in the recovery of the world's health and economy. the 2022 g20 presidency in indonesia could be the right momentum for the indonesian government to reset its focus on the long-term development agenda and to realign the post-covid-19 recovery agenda. indonesia has the opportunity to lead the g20 presidency in harmonizing several global and regional issues. the priority issues discussed at the g20 presidency are understanding the challenges and the need for collective action so that indonesia will focus on three main pillars at the 2022 g20 presidency namely the global health architecture, sustainable energy transition and digital and economic transformation. along with the g20 presidency activities in indonesia, the conflict between russia ukraine heated up again in early february 2022 after the russian combat fleet attacked the ukrainian border, precisely in belarus. the russian troops sent to ukraine are estimated to be in large numbers and can be used as a force to invade ukraine. this was the cause of the escalation of tensions between russia and ukraine after russia had previously been angry at ukraine for having good relations with nato countries [3]. the russia-ukraine conflict has created a catastrophic humanitarian crisis and threatened the stability of geopolitical relations. the war has added to growing concerns of slowing global growth, rising inflation and debt, and a surge in poverty. the main impact of the russia-ukraine conflict on the world economy is rising energy prices and declining confidence in global financial markets, coupled with massive international sanctions against russia. while ukraine is not a significant trading partner for any major economy, it is russia that has a large exposure to the eu and the uk. countries such as china, the united states, germany, france and italy represent one of russia's main import partners, with russian demand accounting for between 1.3-7 % of its gdp [4]. various impacts are felt by countries around russia-ukraine including indonesia. indonesia as the holder of the g20 presidency in 2022 must take a stand against russia's invasion of ukraine. the geopolitical condition caused by the russia-ukraine war is one of the risks faced by the indonesian g20 presidency in 2022. the g20, which was established as a forum for global economic cooperation, is overshadowed by the russiaukraine conflict. according to finance minister sri mulyani, the conflict is a challenge that threatens the values of the g20. for indonesia, managing a meeting in the midst of conflict is a challenge in itself because the indonesian g20 presidency must continue to run according to the agenda of strategic discussions that not only concern indonesia but also the world [5]. there is a sad history in the world economy when there was a monetary crisis that struck from 1997 to 1999. the monetary crisis that occurred led to a movement formed by finance ministers from several major countries in the world. this was later named the g7 or the group of seven. this forum was formed as a response to the concerns that plagued the world community as a result of the monetary crisis that occurred at that time. in 1997 the monetary crisis spread in the asian continent, especially thailand, which experienced a decline in the value of the baht currency. this is because foreign currencies have a minimal nominal amount so that thailand is unable to maintain the value of the baht currency against the united states dollar. this then made thailand have a large debt, which resulted in an economic crisis as a result of the decline in the value of the currency. the development and progress of the world is very much determined by the global commitment in realizing developed and developing countries and having a balance in advancing the economy, environment and social. this commitment is very important in order to synergize the steps and policies of countries in the world in achieving the same goal of prosperity for all. indonesia's involvement in this matter is very important because on several occasions indonesia has become one of the countries capable of synergizing world welfare and peace, one of which is through indonesia's role in initiating countries that are members of asean. therefore, dss vol. 4, 2023, pp.23-28 25 it is not impossible that in 2022 indonesia will be asked to be the g20 presidency which will automatically host the g20 summit in 2022 [6]. in carrying out its duties at the g20 presidency, indonesia took part in helping to resolve the conflict between russia and ukraine. conflict resolution is a social situation in which the conflicting parties in an armed conflict want to make peace and voluntarily choose to coexist and solve the basic causes of the incompatibility of the interests of the two parties so that violence can be stopped [7]. then galtung [8] defines 2 types of peace, namely positive peace and negative peace. positive peace is peace that creates an atmosphere of harmony and harmony between parties who were previously in conflict in social life. meanwhile, negative peace is peace that occurs because of the elimination of things that are seen as negative such as violence, hostility and conflict. in conflict resolution efforts, achieving peace can be done through 3 stages, namely: 1) peacemaking, this stage is the initial stage where peace is sought in conflict resolution. efforts can be made such as negotiations between the two parties and also peace planning. 2) peacekeeping, at this stage the parties must discuss how to implement the results of negotiations and peace plans that have previously been formulated. 3) peacebuilding, at this final stage the parties must rebuild a peaceful atmosphere by restarting communication and cooperation and repairing any damage caused by the conflict. this article discusses indonesia's role in the g-20 forum amid the conflict between russia and ukraine. not only seeing how far indonesia has contributed, but also how important indonesia's position is in playing its role as a member of the g-20. indonesia's contribution can be seen from how it responded to the conflict that occurred between russia and ukraine as a non-aligned country. 2. research method this paper uses qualitative research methods, which are defined as research tools, techniques, and strategies that help writers to collect, interpret and analyze data. qualitative research is a research that basically uses a deductive-inductive approach. this approach departs from a theoretical framework, the ideas of experts, and the understanding of researchers based on their experience which is then developed into problems and their solutions which are proposed to obtain justification (verification) in the form of empirical data support in the report [9]. the data collection technique in this paper is based on internet-based research. the data collected in the form of official reports and press releases from institutions/agencies are categorized as primary data. then data from mass media, articles and scientific journals that have been published are categorized as secondary data. so that the author hopes to provide an in-depth analysis in this paper. 3. results and discussion since december 1, 2021 indonesia has been the g20 presidency country which lasts throughout 2021-2022. the g20 presidency was attended by 19 heads of state, one eu institution, 20,988 delegates consisting of 429 delegates at the g20 summit, 4,581 ministerial meetings, 1,212 sherpa meetings, 8,330 working group meetings and 6,436 engagements groups meeting and is a world forum to discuss world economic issues in a sestimic manner which represents 60% of the world's population, accounts for 80% of world gdp and 75% of world trade [10]. the presence of the g20 is in principle an effort to respond to the problems of global issues, one of which is the global crisis in 1998 which hit the world including indonesia. one of the things that was declared successful in handling the crisis was the policy taken in 2008 which was then followed up through supervision and control of financial problems. the global conditions that occurred in 1998 and 2008 are repeated in 20212022 where there is a crisis due to the covid-19 pandemic which has not subsided, including the global economic crisis which has not subsided. therefore, it is necessary to synergize between g20 members in an effort to overcome the impact of the covid-19 pandemic, including indonesia. there are two important things in indonesia's involvement in the g20 forum, first as a country that seeks to match product quality standards in accordance with global consumers. in this case, indonesia has the opportunity to get input related to its products that are exported abroad. second, indonesia also gets broad market opportunities, technology transfer and open cooperation. indonesia, which has always been a vital dss vol. 4, 2023, pp.23-28 26 point in maintaining regional stability, will be very important to be involved in the g20 forum. in addition, indonesia's involvement is also supported by the interests of a high bargaining power position, because with indonesia's position in the global forum, indonesia's decision can be used as a representation of developing countries in multilateral forums that discuss trade issues at the wto, financial issues at the imf and other relevant issues. developing countries generally have economic problems such as high inflation rates and slow economic growth. inflation is an important economic indicator, its growth rate is always sought to be low and stable so as not to cause macroeconomic impacts that are feared to have an impact on economic instability. the indonesian government through joko widodo stated at the g20 forum that indonesia is very consistent in overcoming problems related to inflation, especially during the covid-19 pandemic by emphasizing consolidation policies with economic diplomacy patterns involving trade, commercial and financial which can certainly overcome the inflation problem that occurs. indonesia's role is very important because it is not only limited to theory but real practice related to the indonesian economy. this means that the indonesian government's political and legal policy at the g20 meeting is to emphasize healthy finance between countries and include healthy competition in financial relations. this practice is certainly very important to do so that the g20 member countries are not exposed to the brink of recession. in another position, the indonesian government as the g20 presidency has also conducted political, legal and security negotiations that not only talk about the issue of war that occurred between russia and ukraine in early 2022 but also bring the main issue of the economy. although the two countries are currently still in military conflict, indonesia has a role to contribute directly in making the two countries maintain economic stability because one of the countries in conflict is the largest wheat supplier in the world, ukraine. this is very important to pay attention to so that the need for wheat is not disrupted and does not become one of the causes of inflation in both g20 member countries and non-g20 members. since 1986, the grouping of finance ministers in the group of seven (g-7) has proved quite important in its function as a forum for informal and substantive discussion on international economic issues. one of the objectives of the forum is to achieve an understanding and closer coordination among policy makers in the g7 countries. on september 25, 1999, in washington dc, finance ministers from the leading industry group group of seven (g-7) announced the formation of the group of twenty (g20). the basic objective of establishing the g20 is to discuss, study and review policy issues among industrialized countries and developing countries with the aim of promoting international financial stability [11]. g20 leaders meet annually and each g20 president invites several state guests annually. in addition, ministers of finance and central bank governors meet regularly throughout the year to discuss measures to strengthen the global economy, reform international financial institutions, improve financial regulations and implement key economic reforms needed in each of the g20 member economies. underpinning these meetings is a yearround program of meetings among senior officials and working groups that coordinate policy on specific issues. in the conflict between russia and ukraine, peacemaking and peacekeeping efforts have been carried out many times but have not really reached a peaceful and peace positive stage, because the conflict is increasingly escalating because the causes of the emergence of the conflict are not really resolved. if this is allowed to continue, the conflict will get bigger and could endanger other countries around russia and ukraine so that peacebuilding efforts are urgently needed so that the two countries can make peace in the long term and the conflict does not escalate again. to reach this stage, cooperation and support from other actors are needed as mediators from nearby countries such as turkey, belarus and our country, indonesia. in this peace process, indonesia became one of the countries that was considered capable of being a mediator and helping to resolve conflicts between russia and ukraine because indonesia already had experience in resolving conflicts, one of which was the cambodia conflict through the jakarta informal meetings in 1988 and 1989. indonesia is also a country that neutral to both russia and ukraine. indonesia as a country that adheres to the free and active principle in foreign relations confirms its consistency with this principle in the crisis between russia and ukraine. the director of europe ii of the ministry of foreign affairs of the republic of indonesia, winardi hanafi lucky emphasized that the principle of free and active does not mean that it is neutral and active, but also contributes both in the form of ideas and assistance for conflict resolution. the attitude taken by indonesia is not just following other countries, but an effort to dss vol. 4, 2023, pp.23-28 27 voice the importance of respecting international legal norms. indonesia will also continue to encourage the use of force to stop so that all parties can resolve the conflict. according to a spokesperson for the ministry of foreign affairs, teuku faizasyah said that there were four points conveyed by the government of indonesia regarding its position on ukraine. first, indonesia is concerned about the escalation of armed conflict in ukrainian territory which is very dangerous to the safety of the people and has an impact on peace in the region. second, indonesia emphasized that it complies with international law based on the un charter regarding the integrity of a country's territory, and condemned any actions that threaten the territory and sovereignty of a country. third, indonesia reiterated that all parties should prioritize negotiations and diplomacy to end conflicts and prioritize peaceful resolution. fourth, the embassy of the republic of indonesia has taken steps to save indonesian citizens in ukraine according to the plan that has been prepared [12]. indonesia made peace efforts by holding meetings with president zelensky as president of ukraine and president vladimir putin as president of russia to open up space for dialogue between the two as a peace effort and encourage an end to the conflict between russia and ukraine. in addition, indonesia's role was even greater during the indonesian presidency at the g20 forum. indonesia's task according to the constitution is to encourage world issues to be resolved in the g20 forum. indonesia's attitude in realizing world peace has been contained in the preamble to the 1945 constitution. in an effort to create world peace, indonesia is considered to still have to put forward wise steps. 4. conclusions indonesia was confirmed as the g20 presidency holder at the riyadh summit 2020 and handed over from italy on october 31, 2021, in rome, italy. the 2022 g20 presidency in indonesia could be the right momentum for the indonesian government to reset its focus on the long-term development agenda and to realign the post-covid-19 recovery agenda. indonesia has the opportunity to lead the g20 presidency in harmonizing several global and regional issues. the priority issues discussed at the g20 presidency are understanding the challenges and the need for collective action so that indonesia will focus on three main pillars in the 2022 g20 presidency, namely the global health architecture, sustainable energy transition, and digital and economic transformation. along with the g20 presidency activities in indonesia, the conflict between russia ukraine heated up again in early february 2022 after the russian fighter fleet attacked the ukrainian border, precisely in belarus. the russia-ukraine conflict has created a catastrophic humanitarian crisis and threatened the stability of geopolitical relations. various impacts are felt by countries around russia-ukraine including indonesia. indonesia as the holder of the g20 presidency in 2022 must take a stand against russia's invasion of ukraine. the geopolitical condition caused by the russia-ukraine war is one of the risks faced by the indonesian g20 presidency in 2022. the indonesian government as the g20 presidency has also conducted political, legal and security negotiations that are not only talking about the issue of war that occurred between russia and ukraine in early 2022 but also bringing the main issue of the economy. indonesia's duty according to the constitution is to encourage that world issues can still be resolved in the g20 forum. indonesia's stance in realizing world peace is enshrined in the preamble of the 1945 constitution. in an effort to create world peace, indonesia is considered to still have to prioritize wise steps. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] w. r. astuti, l. m. fathun, "indonesia's economic diplomacy in the g20 economic regime during the joko widodo administration", intermestic: journal of international studies, vol. 5, no. 1, pp. 47-68, 2020. dss vol. 4, 2023, pp.23-28 28 [2] kominfo, g20pedia, jakarta: djikp kominfo, 2022. [3] s. hidriyah, "escalation of russia-ukraine tensions", research center of dpr ri expertise agency, 2022. [4] d. dano, "analysis of the impact of the russia-ukraine conflict on indonesian fuel oil prices", cendekia: journal of science, vol. 2, no. 3, pp. 261-269, 2022. [5] m. natalia, june 16, 2022. [online]. available: https://ekbis.sindonews.com/read/800039/33/sri-mulyanibeberkan-dampak-perang-rusia-ukraina-terhadap-pertemuan-g20-1655374018. [6] m. junaidi, "indonesian legal politics in controlling world inflation through the g20 agreement instrument", journal of ius constituendum, vol. 2, no. 2, pp. 207-215, 2022. [7] r. &. a. v. kazansky, "conflict resolution approaches towards smart sustainability of internal relations", entrepreneurship and sustainability issues, vol. 6, no. 3, pp. 1468-1484, 2019. [8] galtung, "peace studies and conflict resolution: the need for transdiciplinarity", transcultural psychiatry, vol. 47, no. 1, pp. 20-32, 2010. [9] hardani and et al, qualitative & quantitative research methods, yogyakarta: science library, 2020. [10] martono et al, indonesia 2022 g20 summit: russia vs ukraine war, security and gender, purbalingga: cv. eureka media script, 2022. [11] c. larasati, e. d. natasya, "indonesia's role in the g-20: opportunities and challenges", journal of international relations, vol. x, pp. 42-54, 2017. [12] t. f. arbar, "indonesia's position on the russia-ukraine war", june 30, 2022. [online]. available: https://www.cnbcindonesia.com/news/20220302182710-4-319672/posisi-indonesia-dalam-perang-rusiaukraina. microsoft word 59-64_233 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.59-64 https://doi.org/10.37868/dss.v4.id233 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 59 collaboration between the population and civil registry service with 0707/wonosobo district military command fulfillment of children's rights through child identity card selfira salsabilla1*, george royke deksino2, rizerius eko hadisancoko3, ade surya prabandari putri4, zean elhamas baihaqy5, titin sofiana6, devi kusumawati7 1,2,3republic of indonesia defense university, faculty of defense management, indonesia 4,5,6,7universitas islam negeri sunan kalijaga, faculty of adab dan ilmu budaya, indonesia *corresponding author e-mail: selfirasalsabilla20@gmail.com received: feb. 2, 2023 revised: mar. 20, 2023 accepted: mar. 21, 2023 online: mar. 24, 2023 abstract child identity card is issued by the government to encourage increased data collection, protection, and public services to realize the best rights for children. the existence of the child identity card shows the government's seriousness in fulfilling the rights of indonesian citizens who are still underage to obtain public service rights that are equal to adults. the collaboration between the office of population and civil registration (disdukcapil) of wonosobo regency to issue child identity cards in sigedang is considered effective in targeting the community directly so that people can be more familiar with the functions and benefits of having child identity cards. this research belongs to the type of descriptive research using a qualitative approach which means this research describes a real phenomenon. there were 3 informants in this study as informants. the research data were obtained from various data sources, namely primary data and secondary data. data collection is done through observation, interviews, and documentation. © the author 2023. published by arda. keywords: office of population and civil registration; collaboration; 0707/wonosobo district military command 1. introduction children's rights in terms of identity ownership as fulfillment of population administration requirements are basic things that must be fulfilled. currently through permendagri number 2 of 2016 concerning child identity cards there is to guarantee children's rights in legal protection.. the central government's efforts to implement the child identity card program as an effort to the newest population administration program are a concrete form of protection for children as the state's obligation to protect every citizen. child protection is all activities to guarantee and protect children and their rights so that they can live, grow, develop and participate optimally in accordance with human dignity and values, and receive protection from violence and discrimination. efforts to protect children are absolutely needed, considering that currently there are more and more phenomena that make indonesian children victims [1]. this card is only issued by the regency/city population and civil registration office. the issuance of child identity card aims to improve data collection, protection, and fulfillment of citizens' constitutional rights. child identity card has two types, namely identity cards for children aged 0-5 years and 5-17 years. the terms of issuance, for newly born children, the child identity card will be issued together with the birth certificate. however, for children who are not yet 5 years old and do not have child identity card, the requirements include a copy of the birth certificate excerpt and show the original birth certificate excerpt. in addition, you need a family card of parents or guardians and original id cards of both parents or guardians. dss vol. 4, 2023, pp.59-64 60 issuance of child identity cards in wonosobo regency has reached level 4 and is still continuing to disseminate information and data collection to all regions in wonosobo regency. as of july 2022, the number of children who already had a child identity card was 92,349 (38.93%) and 144,841 of those who did not yet had a total of 237,190 children. previous research in tasikmalaya regency with the title implementation of child identity card policy at the tasikmalaya city population and civil registry service written by nidia rismania dewi resulted that implementation of child identity card policy in tasikmalaya city that, implementation of child identity card policies that are in the department of population and civil registration of the city of tasikmalaya is as expected. procedures and provisions have been carried out properly. the results of research in the field show that this policy has been implemented very well by officers. employees are very proficient in carrying out their duties and serving the community in child identity card services according to established rules. in registering population data, employees only need a short amount of time to make a child identity card without being charged a penny. in the dimension of communication and human resources, it is still lacking and needs to be improved again [2]. another study conducted by windi dwi arista with the title implementation of the child identity card program policy at the badung regency population and civil registry office found that implementation experienced obstacles due to problems with the application system on the computer and problematic networking. besides that, another problem is the supply of electricity in the event of a blackout, because this core equipment requires a stable supply of electricity. related to the use of the child identity card provided by the badung regency population and civil registry service, it has not been maximized and cannot be implemented properly because many people still do not understand the functions and benefits of child identity card [3]. in this study we will use the theory of collaboration and implementation of public policy. in this study, the authors found two problem formulations that will be discussed, namely how to accelerate the achievement of child identity card in wonosobo regency? and how is the implementation of the collaboration with 0707/wonosobo district military command in accelerating the achievement of child identity card? 2. research method in this study, the researcher used a qualitative descriptive research type in which the analysis will be based on the ability and results of the researcher's study to connect field facts, information obtained and existing data. qualitative research methods were used as a procedure in this study which produced descriptive data, namely describing the facts found in the field either in writing or orally obtained from various sources encountered. the sampling technique in this study used the purposive sampling technique, namely in this method using the criteria that had been selected by the researcher in selecting the sample [4]. the analysis technique in this study used qualitative analysis, where the data obtained was clarified and described in easy-to-understand sentences. then it will be analyzed based on the object under study and will be interpreted with existing data or theoretical basis so that the results can be assessed as a whole. all data were obtained from interviews, manuscripts, documentation, official personal documents and other documents that support the validity of obtaining research data [5]. data collection techniques used were interviews, observations, and literature studies. informants who became sources include: 1. commander of kodim 0707/wonosobo. 2. head of the population and civil registration office of wonosobo district. 3. head of service and registration on civil registration office of wonosobo district. 4. sigedang village head. the research location is in the wonosobo regency area (indonesia). the research time was during the activities of tmmd sengkuyung phase ii of 2022 in sigedang village, kejajar district from july 26 to august 24, 2022. dss vol. 4, 2023, pp.59-64 61 3. results and discussion 3.1 procedures for issuing child identity cards in wonosobo district the child identity card is an identity card that every child must have in order to be able to access public services independently. some of the benefits of the child identity card include an effort to improve citizen data collection, protection, and public services, and an effort to provide protection and fulfillment of children's rights as citizens. several legal bases for issuing a child identity card include: 1. law number 24 of 2013 concerning amendments to law number 23 of 2006 concerning population administration. 2. government regulation of the republic of indonesia number 102 of 2012 concerning amendments to government regulation of the republic of indonesia number 37 of 2007 regarding the implementation of law number 23 of 2006 concerning population administration. 3. regulation of the minister of home affairs number 2 of 2016 concerning child identity cards. a consideration for the issuance of child identity cards are: 1. currently children who are under 17 years of age and who are not married do not have a resident identity that is valid nationally and is integrated with the population administration information system (siak). 2. that the government is obliged to provide a valid national identity. 3. that the provision of population identity to children will encourage an increase in data collection. 4. whereas based on the above, the government needs to stipulate ministry regulation regarding child identity card. making a child identity card is a service product from the wonosobo regency population and civil registration office. based on minister of home affairs regulation number 2 of 2016 concerning child identity cards article 1 paragraph (7) this card is only issued by the regency/city population and civil registration office. this regulation is also in accordance with article 2 in the same regulation which contains the issuance of a child identity card aimed at increasing data collection, protection and public service as well as an effort to provide protection and fulfillment of citizens' constitutional rights. the department of population and civil registration of wonosobo regency has carried out the socialization process for issuing a child identity card since 2019. the socialization process is divided into two ways, namely direct and indirect socialization processes. the direct socialization process was carried out through commemorations of national days such as national children's day, and national education day, and through the tni manunggal pembangunan desa (tmmd) program. indirect socialization is carried out through broadcasts on local television and socialization to operators and village officials which is carried out once a year. the child identity card priority targets for wonosobo regency are in 5 sub-districts out of 16 sub-districts, namely sukoharjo district, kalikajar district, kertek district, garung district and kejajar district. however, these 5 sub-districts have met the national child identity card target of 40 percent of the total number of children in wonosobo district. the disdukcapil of wonosobo regency has made several efforts to meet the national child identity card target, including: 1. conduct outreach either directly or through the mass media. the socialization has been carried out by department of population and civil registration wonosobo regency since 2019 directly by inviting village officials and village operators to then convey it to the target community for child identity card. in addition, disdukcapil also conducts socialization directly by participating in events that absorb public interest such as the wonosobo anniversary event, national children's day, expo and others. the department of population and civil registration always opens booths to attract public interest in issuing child identity cards. disdukcapil also conducts socialization through mass media such as making advertisements on the streets in the form of billboards, mass television, live broadcasts, the ministry of communication and informatics website, and others. dss vol. 4, 2023, pp.59-64 62 2. balateka innovation (make deeds directly become deeds, family card and child identity card). this innovation is a program from the disdukcapil of wonosobo regency, where the only requirement is to show a birth certificate and marriage certificate. this service can also be done independently using the disdukcapil whatsapp call center service by taking a photo of the requirements file. so, applicants don't have to bother coming to the disdukcapil office. disdukcapil also delivers documents to the applicant. 3. ball pick up and document delivery services. this service is carried out with the concept of kuda zebra (i came happy community) because when the people concerned want to issue documents in the form of id cards, child identity cards, or certificates they do not need to come to the dukcapil office but are directly escorted to their residence by officers from dukcapil. 4. the constraints experienced by the population and civil registry service (disdukcapil) of wonosobo regency based on the results of interviews with mr. siswanto, s.h., mm. as the head of service and civil registration sector, basically there were no significant obstacles during the socialization and issuance of child identity card processes. however, he said that the lack of human resources (hr) in carrying out every task, such as picking up balls to make id cards and child identity card, was still limited. the wonosobo regency disdukcapil only has 50 employees consisting of 19 civil servant and 31 freelance daily employees (phl), then a service based on sending documents via whatsapp makes it easier for the public because it is considered more flexible but disdukcapil has to sort, match and enter data -the data to the siak application (population administration information system). [6] issuance of child identity cards in wonosobo regency has reached level 4 and is still continuing to disseminate information and data collection to all regions in wonosobo regency. as of july 2022, the number of children who already had a child identity card was 92,349 (38.93%), and 144,841 of those who did not yet have a total of 237,190 children. the various benefits of child identity card issuance include: a child's official identity, child protection, and public service to realize the best rights for children. however, the community does not fully understand the function of the child identity card, so not all of the community benefits from this child identity card. this is caused by several factors, namely: a) lack of facilities and infrastructure to carry out outreach; b) there are still many people who think that child identity cards is not important; c) child identity card is not yet mandatory in wonosobo regency; and d) although the procedure for issuing child identity card is easy, there are still people who have not fulfilled the completeness of the documents such as child birth certificates, family cards or other requirements. 3.2 collaboration between kodim 0707/wonosobo and the service in issuing child identity card wonosobo regency epistemologically, the word collaboration comes from english, namely, "co-labor" which means working together. in the 19th century, the word collaboration came into use when industrialization began to develop. organizations at that time became increasingly complex. divisions in the making of the organizational structure began to be made for the division of tasks for the workforce in the organization. organizational complexity is the starting point for collaboration in various organizations [7]. philosophically, collaboration is an effort made by various parties to achieve the same goal. according to schrage in [8], collaboration is an effort to unite various parties to achieve the same goal. collaboration requires various kinds of actors both individuals and organizations who work hand in hand to carry out tasks in order to achieve common goals. collaborative governance is a forum used to achieve a goal. according to [9], collaborative governance is a condition in which the government fulfills public goals through collaboration between organizations and individuals. the same thing was also expressed by [10] who stated that collaborative governance is a condition when the government and the private sector seek to achieve a common goal for society. collaborative governance can also describe a state of interdependence between actors. the desire to do collaborative governance arises because the actors are aware of the limitations they have. then, these actors need to express their desire and willingness to forge closer relationships with other actors. each actor involved needs to acknowledge the legitimacy held by other actors. once the actors are committed to collaborating, it is necessary to build a sense of shared ownership of each collaboration process [11]. the collaboration built by disdukcapil in the wonosobo district was carried out because of limitations, namely in the process of conveying information related to the importance of having a child identity card so that it collaborates with kodim 0707/wonosobo as a medium for conveying information to the public, especially through tmmd activities. dss vol. 4, 2023, pp.59-64 63 based on the opinions of various experts, it can be concluded that collaborative governance is a process of cross-sectoral multiorganizational network structures (government, private sector, civil society) that make collective agreements, joint decisions, reach consensus through formal and informal interactions, the creation and development of norms in interactions that mutually beneficial in achieving common goals. therefore, in collaboration, the interactions that appear are egalitarian, that is, all actors have the same position. republic of indonesia law number 34 of 2004 concerning the indonesian national army (tni) stipulates that the duties of the tni include military operations for war (omp) and military operations other than war (omsp) [12]. implementation of military operations other than war which must be based on state policies and political decisions. military operations apart from war, one of which is the existence of community service operations which are the implementation of omsp in the form of assisting local governments. one form of service operation is the tmmd (tni manunggal membangun desa) program. the tni manunggal build village (tmmd) program has a physical target as well as carrying out non-physical activities, by providing counseling and outreach, one of which is the success of population administration services in the form of issuing child identity card in sigedang village, kejajar district, wonosobo regency. with the role and participation of kodim 0707/wonosobo which is implementing the tmmd program in sigedang village, it facilitates direct socialization by targeting the sigedang village community. this was felt to be quite effective because the tni, through babinsa and members of the tmmd task force, immediately gave an explanation to the public about the benefits of owning a child identity card [13]. this collaboration shows a significant increase in participation in child identity card services, as evidenced by the achievement of 540 child identity card services in 30 days, whereas if there was no collaboration, only up to 60 cards [14]. 4. conclusions issuance of child identity card is very important for the fulfillment of children's rights, especially in the village of sigedang, wonosobo. the department of population and civil registration (disdukcapil) of wonosobo regency has carried out various methods ranging from outreach, and innovation, to picking up and providing services via whatsapp to facilitate access to child identity card issuance. however, with the collaboration with the kodim 0707/wonosobo which works directly with the community, the child identity card data collection to be submitted to the disdukcapil to issue child identity cards is felt to be very effective because the increase in requests for child identity card issuance in sigedang village is quite significant. the obstacles experienced by the disdukcapil of wonosobo regency were not significant obstacles and did not reduce the performance of child identity card issuance, which incidentally was easy and straightforward. the length and absence of issuance depend on the completeness of the data that goes to the disdukcapil of wonosobo regency. while the process itself only takes a maximum of two working days. acknowledgments thank you to the commander of the kodim 0707/wonosobo, the head of the wonosobo regency population and civil registration office, and the head of sigedang village who have agreed to provide information and supporting information in writing this article. declaration of competing interest the authors declare that they haven’t any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] i made sila, i made purana, dan a. r. b. a. “policy implementation of minister of home affairs dss vol. 4, 2023, pp.59-64 64 regulation no. 2 of 2016 concerning child identity cards (kia) at the denpasar population and civil registry service”, ipdn journal, vol. 11, no. 1, pp 84-96, 2020. [2] n. dewi, “implementation of the child identity card (kia) policy at the population and civil registry service in the city of tasikmalaya“, scientific journal of administrative sciences, vol. 10, no. 1, pp 913, 2019. [3] wd. arista, w. suderana, “implementation of child identity card (kia) program policy at the badung regency population and civil registry service”, social dynamics scientific journal, vol. 3, no.1, pp. 56-60, 2019. [4] sugiyono, understanding qualitative research, bandung: alfabeta, 2014. [5] j. w. creswell, research design: qualitative, quantitative and mixed methods approaches (4th ed.) thousand oaks, ca: sage, 2014. [6] results of interviews with mr. tarjo (head of the wonosobo regency population and civil registration service) and mr. siswanto, s. h., mm. (head of services and civil registration). [7] j. wanna, “collaborative government: meanings, dimensions, drivers and outcomes, on o‟flynn”, jannie & wanna, john. collaborative governance: a new era of public policy in australia?, canberra: australian national university e press, 2008. [8] j. harley, n. blismas, “an anatomy of collaboratuon within the online environment, on anandarajan, murugan (ed)”, e-research collaboration: theory, techniques and challengers, heidelberg: springer international publishing, 2010. [9] j. d. donahue, r. j. zeckhauser, collaborative governance: provate roles for public goals in turbulent times, new jersey: princenton university press, 2011. [10] m. holzer et al, an analysis of collaborative governance models the context of shared services dalam lauer schachter, hindy kaifeng, yang (ed). the state of citizen participation in america, charlotte: information age publishing, 2012. [11] c. ansell, a. gash, “collaborative governance in theory and practice”, journal of public administration research and theory, vol. 18, no.4, pp. 543-571, 2007. [12] law number 34, year 2004, concerning the indonesian national armed force. [13] interview results with lt. col. inf rahmat, s. e., m.sc (commander of 0707/wonosobo military district command). [14] interview results with the head of sigedang village. microsoft word 32-49_188 issn 2744-1741 defense and security studies review article vol. 3, 2022, pp.32-49 https://doi.org/10.37868/dss.v3.id188 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 32 cybersecurity challenges in industry 4.0: a state of the art review elmedina avdibasic1, amanzholova saule toksanovna2, benjamin durakovic1* 1 international university of sarajevo, bosnia 2 international information technology university, kazakhstan *corresponding author e-mail: bdurakovic@ius.edu.ba received: jul. 22, 2021 revised: aug. 27, 2022 accepted: aug. 13, 2022 online: aug. 18, 2022 abstract cybersecurity is an important topic for industry 4.0, which will face a lot of nontraditional challenges before it can be fully implemented to help society. the objective of the study is to recognize recent cybersecurity trends, newly occurring threats and challenges as well as their potential solutions. the articles reviewed in the paper are found through science direct, scopus, semantic scholar and google scholar. after reviewing them, ideas from articles were grouped together to show how different articles had similar thoughts. through the analysis of 70 articles, it was found that cybersecurity still needs a lot of improvement in order to efficiently implement industrial internet of things (iiot), especially since many articles underline the need for security-by-design approach, followed by regular updating. key challenges are lack of awareness and security experts, increased cybercriminal and the fact that the chain is as only as strong as its weakest point. some of the most important solutions include incorporating security into design, stronger encryption, regular updates to patch vulnerabilities and good prevention and detection mechanisms. once cybersecurity challenges are overcome, industry 4.0 will be able to bloom to its full extent. © the author 2022. published by arda. keywords: cybersecurity, industry 4.0, internet of things (iot), artificial intelligence 1. introduction as humanity progressed throughout the time, the focus was always on developing better technologies. purpose of industry revolutions is to improve production. the first industrial revolution brought us mechanization, second one introduced mass production, and third one was about automatization. next in line is fourth industrial revolution, or as some like to call it, industry 4.0. some of the concepts of industry 4.0 is to make the machines smarter by introducing machine learning, and then interconnecting those machines so that the data can be exchanged between them. therefore, the following core components of industry 4.0 can be recognized [1]: 1. cyber-physical systems. purpose is to combine networks and computers-which are cyber part, with manufacturingwhich is physical-systems part. the idea is to have manufacturing processes under the surveillance of computers. 2. smart factory. a background system that manages the virtual and physical systems, gives almost real time feedback about manufacturing. it’s basically a self-sustaining factory that does not need intervention of humans. 3. internet of things. dss vol. 3, 2022, pp.32-49 33 cooperation and communication of devices that are part of one cyber-physical system is provided through internet of things. they can share the data and help each other with problem solving. 4. internet of services. all the services that are needed are accessible through the internet. there are few questions that arise when it comes to the challenges of industry 4.0. the articles that are written about the industry 4.0 and its challenges discuss these questions and their possible answers, ways to overcome these challenges. do the companies have enough competent staff needed to shift to this new technology? do they have the right infrastructure needed to make this change? another very important question is regarding the data privacy, whether the shared data is safe. how to protect the consumer and consumers’ data? how secure are the clouds where the data will be uploaded, and how exactly is the data going to be manipulated? cybersecurity surely is one of the biggest challenges that 4.0 will face [1]. figure 1 shows the context of cybersecurity in the big picture of industry 4.0 and industrial internet of things (iiot). figure 1. industry 4.0, iiot and cybersecurity context security needs to be integrated into the design. after releasing the initial product, its software needs to be updated regularly to patch up new vulnerabilities. data encryption will need to be improved in order to keep data safe, and employees will need to be trained to keep up with new security measures. lack of awareness could be a problem, so both users and employees will need to be educated about the importance of cybersecurity. since the cybersecurity represent one of the biggest industry 4.0 challenges thus, the purpose of this paper is to provide most recent advancement in cybersecurity for industry 4.0. therefore, the paper is structured as follow: section 1.2.2 section 2 explains methods that were used to choose the articles to be reviewed for this paper. section 3 results and discussion, contains literature review with tables and diagrams with the actual article analysis. ideas from the articles are grouped and combined into following topics: general information about industry 4.0, hyperphysical systems, smart manufacturing, internet of things and cybersecurity for health system in industry 4.0. at the end in section 4 conclusion is made. 2. method applied in study first database that was used to obtain sources used in this paper was sciencedirect.com. the key terms for search were “cybersecurity industry 4.0”. the total number of results were 344. among the article types that had these keywords were editorials, review articles, book chapters and research articles. after filtering the search results, two different diagrams were created in excel to visually present the popularity of the topic and areas of research where the topic was present. to choose among the huge number of articles and decide which articles will be used in the paper, the relevancy “test” was performed. relevancy was determined in the following way: the article had to have words “cybersecurity” and “industry 4.0” in its title, and it had to be written over the period of past few years. second part of the articles was found through google scholar, by searching the keywords “cybersecurity industry 4.0” and alternative version “security industry 4.0”. among many articles that passed relevancy test on google scholar, 16 of them were chosen. third database that was used for finding articles was semantic scholar, and it has turned out to be the one with the largest number of relevant recent studies. dss vol. 3, 2022, pp.32-49 34 another way of finding articles was through the references of already chosen articles – if the article chosen was of good quality, it probably cited reliable, quality sources, so those were taken into the consideration as well, as long as they were written from 2015 onward. since the topic of the paper is focused on current literature, the spotlight was on the papers written in the period from 2015 to present, since the papers written before that period are most likely not relevant anymore, or not as relevant as the ones written in the past few years. the first part of the actual research was to read the abstracts of articles, as well as summary/conclusion part of the article if it was available, since in many cases it provided information that was helpful in deciding whether the article was relevant to the topic and if it contained information that was worth including. after choosing the articles that would be reviewed for this paper, second step was to read full articles to gain better understanding of the topic. after that, main ideas were compared between different articles and important points in the articles were summarized. information from articles were then grouped by similar topics. 3. results and discussion as found in the literature, topic of cybersecurity for industry 4.0 has been discussed/mentioned in 332 articles available there. popularity of this topic has certainly increased over the years, as can be seen from figure 2 below. results from the first initial search are included in the diagram. figure 2. topic popularity referring to figure 2, it is observed that this research field is pretty young. the first paper publish was in 2002 but since 2016 the number of publications is gradually increasing from year to year. referring to figure 2, it is observed that this field of research is quite new and emerging. the first work was published in 2002, but until 2015 there was no noticeable increase in the number of publications. since 2016, the number of publications has been increasing significantly from year to year. which is an indicator that the topic attracts more and more researchers from all over the world. second diagram in figure 3 shows the research areas where this topic was mentioned/written about. as expected, computer science, engineering and decision science are most frequent scientific areas in which articles appeared. figure 3. areas of research 0 50 100 150 200 250 300 350 400 2002 2007 2011 2013 2014 2015 2016 2017 2018 2019 2020 2021 n um be r o f a rt ic le s year 0 50 100 150 200 250 300 350 400 450 500 materials science chemical engineering environmental science psychology energy social sciences business management and accounting decision sciences engineering computer science number of articles dss vol. 3, 2022, pp.32-49 35 below are shown tables that contain categorized research papers used in this review. table 1 shows articles sorted by topic they were used for. table 1. division by topic industry 4.0 cyber-physical systems smart manufacturing internet of things healthcare published article [56] [32] [26] [17] [59] [58] [57] [50] [33] [27] [25] [24] [18] [65] [64] [63] [62] [61] [60] [37] [35] [34] [22] [21] [20] [19] [13] [12] [11] [9] [8] [6] [5] [66] [36] [66] [67] [68] [69] [70] results obtained from articles, threats that would cause problems and possible solutions are specified in the tables down below, together with the references where those were mentioned. table 2. threats mentioned in articles table 3. solutions mentioned in articles threats and challenges references lack of awareness [45] [46] [47] lack of experts [48][58] companies are unprepared [60] large attack surface due to many entry points [12][27][30] [68] vulnerable device connected to a network [6][16][27][22] weak link in a supply chain [25][59] unsafe data exchange [23][26][49] stealing sensitive data for private benefit [5][16][31][69][50][53][66][40][68] [70] blackmailing [5][24] dos attacks [13] [23] [61][6] harming safety of people [51][16] [36][67] [68] financial harm [5][16][52][69] default passwords [21][34] unsafe updates, or lack of [63] [12][35] interruption in providing services due to connection being lost [11] [8] solutions references training employees, educating people [48] [58] [15] [7] [3] security-by-design [24] [15] security embedded in layers [2] [3] identifying most vulnerable spots and putting extra protection there [54] [17] [65] [41] prevention and detection techniques [24] [15] [25] additional authorization and authentication [4] [18] dss vol. 3, 2022, pp.32-49 36 3.1 analysis it is worth noting that throughout the paper, terms “industry 4.0”, “industrial internet of things (iiot)” and “digital manufacturing” will be used interchangeably. “industrial internet of things” is the same as “industry 4.0” or the term “smart manufacturing”, but it needs to be stated that industry 4.0 is a broader term than smart manufacturing is [38]. even though cybersecurity is widely used word, the universal, standard definition for it doesn’t exist. it’s definitions vary and they can be subjective [44]. with that in mind, a couple of definitions are provided down below. the purpose of that is to show what meaning cybersecurity has in the further sections of this paper. 1. definition by public safety canada: “the body of technologies, processes, practices and response and mitigation measures designed to protect networks, computers, programs and data from attack, damage or unauthorized access so as to ensure confidentiality, integrity and availability [10].” 2. definition by kaspersky, which is one of the leading companies that are taking care of cybersecurity: “cyber security is the practice of defending computers, servers, mobile devices, electronic systems, networks, and data from malicious attacks. it's also known as information technology security or electronic information security [42].” 3. definition by us government: “cybersecurity is the art of protecting networks, devices, and data from unauthorized access or criminal use and the practice of ensuring confidentiality, integrity, and availability of information [43].” since vulnerability is mentioned very often throughout this paper, the definition of vulnerability is quoted as well. vulnerability is: “weakness in an information system, system security procedures, internal controls, or implementation that could be exploited or triggered by a threat source [71].” defense advanced research projects agency has stated that “security shield for internet of things” is among the 4 programs that are predicted to have impact bigger than the internet had. this is probably due to the fact that iiot connectivity will bring cybersecurity to another level because of the many non-traditional challenges it will face [28]. among all the other challenges that industry 4.0 will be facing, cybersecurity is one of the most serious ones. since 4.0 introduces a lot of new concepts, it will not only have to deal with usual security problems that occur when certain system is connected to the internet, but it will also have to deal with security and privacy issues that will be unique and characteristic for industry 4.0. that is what may make it harder to troubleshoot these problems, and unless these issues are properly taken care of, industry 4.0 may not achieve its full potential [14] in one of the surveys about digital manufacturing, companies were asked about largest challenge they are facing while implementing digital manufacturing. only 18% stated they were concerned about data security [45]. annual wef report regarding global risks stated for year 2019 that unfortunately a lot of tech companies didn’t see “security by design” as their primary interest, but as something secondary-their main goal was, expectedly, to put their goods on the market. for 2019, cyber-attacks were listed as the 5th in the list of the "top 10 risks" by likelihood, and 7th by the impact it would have [46]. as for the 2020 report, cyber-attacks were ranked 8 by impact and 7 by likelihood [39]. solutions references direct-to-machine data transfer [18] computational and cyber threat intelligence [54] [24] stronger encryption [3] [63] [26] blockchain technology [55] high availability through redundancy [8] controlled areas [53] [40] ditching default passwords [3] [62] encouraging reporting vulnerabilities [3] [62] regular updates [3] [64] [62] certifying cybersecurity technologies [64] dss vol. 3, 2022, pp.32-49 37 it is important to raise the awareness of the importance of cybersecurity. if the idea of industry 4.0 is implemented and the machines and different phases of the production are connected, then it is also necessary for all the workers who are involved in the process of production to be trained to understand and practice security requirements [15]. right now in, in some environments cybersecurity is underestimated and is seen only as a “technical” problem, and many companies see it only as an additional, maybe even unnecessary cost that they are not eager to pay [47]. in one of the articles, it was mentioned how the security had the image of being a “trouble-maker” in traditional manufacturing environments [29]. however, cybersecurity in the industry 4.0 has the opportunity to be seen as an enabler, something that could provide additional valuable services. another article mentioned the same ideacybersecurity produced opportunity for providing “additional services” in following way: due to cyber threats that come with new technologies, companies that are able to provide protection, security and reliability within their products can profit from that through “selling” those three promised features. however, developing technologies that would ensure the highest percentage of security may be pretty expensive, and if the awareness of importance of cybersecurity is not present, then the question is whether the customers would be willing to pay for such product [47]. raising awareness is something that comes up whenever cybersecurity is mentioned. people will have to be trained to think of the cybersecurity intuitively. just like a person checks left and right before crossing the street, it needs to become intuitive to check if the iot device is secure enough, and that paying more for a secure device is worth it [7]. another roadblock for adopting the industry 4.0 security procedures beside lack of awareness is lack of security experts. people who already work in ot or it security are experts in that area, but for industry 4.0 they will need to be trained to work in new environments that industry 4.0 brings with itself. there will also be need to raise awareness about security issues of new technologies, that are unlike any traditional security issues that they may have been facing. an enisa recommendation for this is to raise awareness through training the employees and helping them transition, as well as educating the students through their courses about the importance of security in industry 4.0, which would help with raising awareness and understanding [48]. interconnecting different objects comes with a certain risk. in one of the articles, they give an example of business partners who are exchanging sensitive data [23]. industry 4.0 should provide them with a safe space for the data exchange, however this space can be reached and attacked by outsiders, via dos attacks that can interrupt the data flow and cause integrity issues. compared to systems that are not interconnected, systems in the iot environment pose a bigger threat due to the larger surface for cyber-attacks [30]. up to the recent days, number of entry points was rather restricted. this made cybersecurity a lot easier to deal with, but still there were a lot of cyber-attacks happening. with iiot happening any time now, traditional security measures that were in practice until now will need to be changed and improved to correspond to the huge scale of iiot. companies will now be in need of security measures that cover the whole system and all of the many entry points they have, so security will need to be implemented among many layers [2]. another article supports the layered security approach and gives its suggestions. the security measures for each layer that the article is recommending are following [3]:  network layer: using firewalls, antiviruses, use more secured wireless network like wpa2 and not wep, using encryption when transferring data to the cloud, using many ssid-s.  application layer: checking for csrf vulnerabilities, as well as vulnerabilities in the versions of open-source libraries and third parties that an application is using, changing default password if an app is a service provided by some other company; using https, encryption, setting normal behavior which will help to later identify any abnormalities.  device layer: updating firmware on time, changing any default passwords and configurations, testing the device regularly.  physical layer: limiting access to certain areas by using secure keys/badges, using security cameras.  human layer: training employees regularly, educating users on how to secure their devices, encourage employees and users to report any vulnerabilities they may find, and reward them for doing so. among “the top ten privacy risks” are information transfers that aren’t secure enough, collecting information unrelated to the main function, and possibly forwarding that and other information to the third parties [49]. there are different types of sensitive data that could be stolen. one of the worst scenarios mentioned in one of the articles was attackers stealing the information that is crucial for product designbasically stealing ideas for new products, as well as the instructions for manufacturing that product. this could also lead to the emerging dss vol. 3, 2022, pp.32-49 38 of more counterfeit products [50]. a threat can come from the inside as well. employees who have access to the sensitive data can steal it and sell it to the outsider with the highest bid [31]. cybersecurity is especially important when it comes to the idea of smart cities and buildings. each building needs to be designed with security in mind, since all the systems will be connected. control systems, security cameras, fire detectors, elevators, even electricity, and many other services that are provided could be compromised. the damages that could be done is interrupt in providing these services, which could harm safety of people and safety of sensitive information in the banks or other organizations. a way into the smart building could be hacking the most vulnerable spot, like smart tv, which wouldn’t be hard since up to date there aren’t any anti-virus/malware software for smart tvs [16]. as for the attacks on cars, they won’t need to be physicala connected vehicle will have connections to the cloud, wireless and bluetooth connections that could be compromised, and through these connections an outsider could meddle with car controls. the center of attention for security and protection will need to be transitioned from the physical aspect to the cyberattacks [51]. cybersecurity attacks leave a mark on the financial state as well. kaspersky lab conducted a worldwide survey in 2017, and reported that among the companies that endured cyber-attacks, 20% of them stated that harm on their finances has increased due to these attacks, and that lead them to increase their fund for cyber security systems [52]. to achieve a healthy and strong system that has effective cybersecurity, it is important to have cyber-attack prevention tactics, as well as detection methods and response procedures [25]. one of the solutions for physical control and data protection that was mentioned in two different articles was “controlled areas”, also called protected areas [40] [53]. rooms where sensitive information is spoken so it can be heard need to be protected so that no outsider could get access to the data. to prevent third partied from hearing sensitive data, sound insulation can be implemented for those rooms. to prevent radio and electromagnetic signals that contain sensitive data from getting beyond the walls of protected rooms, the electromagnetic shielding for the rooms could be implemented as well. in order for the company to be ready to deal with cybercrime and defend from it, there are a couple of things they can do to ensure effective cybersecurity. a company needs to analyze what their most important assets are and then invest in protecting them. cyber threat intelligence helps to prepare by analyzing when and where the threats could occur. there needs to be a constant improvement of cybersecurity. topic of security needs to be a recurring element, a regular part of meetings and discussions [54]. general solution for protecting the system as whole would be to estimate in advance what are the most vulnerable and the most critical parts of the network that need to be protected [41]. they say that earlier systems did not give much thought to the cybersecurity during their design phase. and now a different approach is needed, where the security would be integrated in the design. instead of focusing on responsive actions that would need to be taken after a cyber-attack, they propose focusing on preventive policies that would provide security from the start [15]. some of the measures that can help with assuring security would be authorization of the software on the connected devices, authenticating the device prior to the data transfer to/from the cloud, and using firewalls [4]. a new approach to cybersecurity is using blockchain technology. it is famous for being used in bitcoin, and with its help, the transactions are more secure and safe. users on the different ends of transaction don’t have to trust each other, and after the transaction is confirmed, it isn’t possible to reverse it. due to its decentralized nature, blockchain is basically impossible to hack, which makes it safe and perfect to use in cybersecurity for industry 4.0 [55]. 3.2 cyber – physical systems industrial control systems (ics) is a part of cyber-physical systems. well performing ics present a solid foundation for the success of industry 4.0. ics are category of control systems that are used for handling and automatization of industrial processes. with bigger connectivity comes a bigger risk of cyber-attacks, which means that ics will need better security. as one article noted, south-east asia had the largest percentage of ics infections in 2018-61% of their devices were attacked in h1 of 2018, and 57.8% in h2 of 2018 [56]. number of articles suggest using cad (computer aided design) in the process of creating cyber-physical model [32]. together with offering a lot of amazing features, cad model also comes with its own cybersecurity risks. one of the inevitable things regarding industry 4.0 is collaboration via cloud when developing new products. however, it is going to be a challenge to protect sensitive data about the model of a new product, if it is shared via cloud. one of the articles suggested using customized encryption for cloudshared cad models. there would be two different types of users, owner of the model and its collaborators. dss vol. 3, 2022, pp.32-49 39 the way that the encryption would work is the owner of the model would upload to the cloud cad model in encrypted form, and then collaborators can download the encrypted model from the cloud and decrypt it [26]. another article offers the steps for managing the cybersecurity risks. first thing is to identify those risks, by identifying weaknesses, as well as possible threats. second is analyzing those risks, by determining how likely is it for such situation to happen, as well as determining the possible impact of the risk. third would be evaluating risks. what would the magnitude of the risk be, is the risk acceptable? last step are risk controls, and it would be performed by implementing controls for the risk [17]. 3.3 smart factory the idea behind smart factory is to get more from the manufacturing by transitioning from the traditional way to the industry 4.0 way – creating a network of suppliers and a connected system that uses real-time data and adjusts the manufacturing so that the new demands can be met. that results with a system that is overall more efficient and that could rank better than the other competitors in market [57]. smart factory, just like other parts of industry 4.0, will face certain challenges. types of jobs that people will have in factory will evolve into something more complex, as the automation takes over the repetitive and dull jobs. some may argue that automation presents a threat to the current job positions in manufacturing. however, the jobs will still remain, but the tasks that workers will do will change. companies will need workers who will operate on new technologies that industry 4.0 will bring. right now, they say that it’s hard to start implementing new digital technologies because there aren’t enough workers that have skills that are required to be able to run those technologies. companies will eventually have to invest in training their employees and equipping them with skills needed to operate the new technologies. apart from this challenge, another one will be dealing with cybersecurity [58]. table presents summary of results on key cybersecurity challenges for cyber-physical system and smart factory. table 4. key cybersecurity challenges for cyber-physical system and smart factory challenge result reference manufacturing processes as potential risk.  multiple connected suppliers may not have the same security levels. probably smaller suppliers, will have weaker cybersecurity which will cause a threat to the rest of the connected suppliers.  an outside attacker could identify the weakest link and use it to get access to the rest of the suppliers.  92% of overall cyber-attacks for a year happened in a smaller organization. this would be a scenario likely to happen with smart manufacturing supply chains where outsiders would attack smaller companies because of their vulnerability,  interconnections come with a certain risk but solution maybe to limit the communication between the machines or separate the machines that are used for production from the personal computers that are on the same network. [18], [25], [33], [50], [59]. industrial control systems (ics).  south-east asia had the largest percentage of ics infections in 2018-61% of their devices were attacked in h1 of 2018, and 57.8% in h2 of 2018  collaboration via cloud when developing new products is challenge to protect sensitive data about the model of a new product  there would be two different types of users, owner of the model and its collaborators and the encryption would work cad files uploaded to the cloud, and then collaborators can [17], [26], [56]. dss vol. 3, 2022, pp.32-49 40 challenge result reference download the encrypted model from the cloud and decrypt it.  risk identification, analysis, evaluation and control are necessarily phased of the risk management. smart factory challenges.  companies have to be prepared for cybersecurity challenges such as: detection of viruses and malware before they get into system, and using computational intelligence for spotting and tracing threats like viruses and hackers that could lead to data manipulation, cyber stalking, blackmailing, executing terroristic acts, and other actions that may harm the system or parts of the system.  industry 4.0 depends on data that is transmitted from sensors in real-time, which puts security at risk due to number of entry points that each network has and increases the potential number of weaknesses in the system and vulnerabilities that hackers may use.  types of jobs that people will have in factory will evolve into something more complex, the jobs will still remain, but the tasks that workers will do will change.  companies will need new talents who will operate on new digital technologies that industry 4.0 will bring.  companies have to invest in training their employees and equipping them with skills needed to operate the new technologies. [24], [27]., [58], one of the articles says that security-by-design is mandatory for securing smart factories. it includes detection of viruses and malware before they get into system, and using computational intelligence for spotting and tracing threats like viruses and hackers that could lead to data manipulation, cyber stalking, blackmailing, executing terroristic acts, and other actions that may harm the system or parts of the system [24]. industry 4.0 depends massively on data that is transmitted from sensors in real-time. that puts security at risk because of many entry points that each network has, and then all of those networks are interconnected as well. this increases the potential number of weaknesses in the system and vulnerabilities that hackers may want to take advantage of [27]. an example of a possible risk would be the connection of suppliers and their manufacturing processes [25]. multiple suppliers are connected in a supply chain, and they probably will not have the same security levelssome of them, probably the smaller suppliers, will have weaker cybersecurity which will cause a threat to the rest of the suppliers that are connected to that chain. an outside attacker could identify the weakest link in the chain and use their weak security in order to get access to the rest of the suppliers. in one of the reports, it was stated that 92% of overall cyber-attacks for that year happened to the smaller organizations. this would be a scenario likely to happen with smart manufacturing supply chains (unless the security is better taken care of than it is now), where outsiders would attack smaller companies because of their vulnerability, and since they represent the easiest entry into the chain, that would lead them to bigger companies that are their actual target. these small companies would represent a risk for the bigger organizations since they could be easily attacked through them, despite the cybersecurity measures that they have accomplished in their own company [59]. since interconnections come with a certain risk, one of the articles suggested that a solution would be to limit the communication between the machines, and limit the machines that can communicate with each other. additionally, they could also separate the machines that are used for production from the personal computers that are on the same network, that way limiting the access [50]. dss vol. 3, 2022, pp.32-49 41 several solutions for protecting critical data are offered throughout these articles. one of the solutions discussed the situation when certain data would need to be transferred through different layers, until it finally reaches the machine that executes it. solution would be to skip all the unnecessary carriers of that data, and transfer it directly to the machine, with help of authentication and authorization. it would also strip off any non-essential data – only the information that is required for the execution would be given to the machine [18]. also it is important to remove the walls between information technology sector and operations technology sector, and have them share the information with each other, since these two are the sectors that will be crucial for effective defense of industry 4.0. focal point for it is cia-confidentiality, integrity and availability, and ot mostly puts focus on availability. issue with ot is that they lack room for adding cybersecurity into the equation in a way that wouldn’t have disadvantageous impact on production [33]. 3.4 internet of things one of the articles argues that the security is the number one challenge of iiot [19]. one of the surveys that was conducted among 400 experts from four countries uk, germany, us and japan, concluded the following:  regarding the iot security, 75% stated it was important, however just 16% stated that the company they were working for is ready for it.  companies were generally not prepared for each part of the security ensuring action, which consists of predicting, preventing, detecting and reacting.  regarding the strategies for cybersecurity that can be applied to iot as well, less than two thirds stated that they have one ready [60]. another article notes that systems that are part of iot should from the very beginning be designed with possibility of integrating it with the other systems [20]. protection measures need to be taken regarding protecting 3 things: device security, data security and privacy of the user. to protect the security of device, it needs to be saved from engaging in distributed denial-of-service (ddos) attacks and harming devices that are connected to the same network as that device. protecting data means taking care of confidentiality, integrity and availability (cia) of information on the iot device, ensuring its security while its being transferred and analyzed. protecting users’ privacy means protecting the personally identifiable information that could possibly impact the user, either directly or indirectly [61]. accountability is important when implementing security procedures since it distributes responsibilities and holds objects accountable for their actions. accountability isn’t enough to prevent cyber-attacks from happening on its own, but it does help to make sure that the rest of security methods, such as confidentiality or integrity are functioning well [9]. as availability is one of the key features that cybersecurity keeps safe, availability for the crucial devices needs to be as close to the 100% as possible. a very high percentage of availability at all times can be accomplished through redundancy, which in essence means that in case that one part fails to provide service, then there exists a backup of that same part that can provide service instead [8]. possibility of losing connectivity could interfere with proper functioning of iot device, and potentially reduce its security. extreme case would be inability of the device to function without the connection to the internet. solution that bitag proposes is to configure device in a way that it can still fulfill its main purpose even in case of losing the connectivity [11]. table 5 shows summary of results related to iot device cybersecurity. table 5. review of key iot device cybersecurity results challenge result reference iot devices mass production.  cost of producing iot devices will decrease but update feature may be costly / impossible due to limited resources.  updates of iot devices are one of the possible places for the outsiders to attack. updates need to be secured especially since they are usually arranged for a specific time slot and executed throughout the downtime.  more iot devices means more entry points that can be hacked. [12], [35], [36], [37], [63], [65]. dss vol. 3, 2022, pp.32-49 42 challenge result reference unpreparedness for iiot security.  iiot security is the number one challenge.  protection measures have to include: device security, data security and privacy of the user.  protecting data means taking care of confidentiality, integrity and availability (cia) of information on the iot device, [19], [20], [61]. unpreparedness for iiot security.  400 experts from uk, germany, us and japan concluded that 75% stated it was important, 16% stated they were working on it.  companies were generally not prepared for each part of the security ensuring action, which consists of predicting, preventing, detecting and reacting  regarding the strategies for cybersecurity that can be applied to iot as well, less than two thirds stated that they have one ready. [60]. employees smart devices (shadow devices) connected to organization’s network, without knowing of it department.  these shadow devices are a door for hackers for entering the organization’s network.  46% of organizations found shadow devices connected to their corporate network.  only 25% of organizations haven’t discovered any shadow devices connected to their network.  it will be possible to turn many iot devices into botnets and use a massive army of modems, controllers, routers and other devices to execute a ddos attack. [13], [21], [22]. default passwords.  default passwords for commercial iot devices could usually be found online in less than half an hour.  most users want to buy a new technology, but they are too lazy to read the user manual and check how to change password or restrict access. [21], [34]. home automation controllers and remote controllers for garage doors.  hackers use that data from these devices identify perfect timing for executing robberies.  criminals from these data when the user is at home and when the garage doors are opened / closed. [5]. healthcare iot devices.  healthcare infrastructure is among the most frequently targeted industries for cyber-attacks.  hackers can attack iot medical devices and send commands to the device and to stop them working.  these devices are vulnerable harming patient’s privacy and breaking physician-patient confidentiality, and harming patients and possibly causing more health problems.  medical information is attractive to attackers to be used to get [36], [66], [67], [68], [69]. dss vol. 3, 2022, pp.32-49 43 challenge result reference prescription medication and drugs that can be sold on darknet, or occasionally contains the data that can be used for opening new bank accounts or taking out loans. insufficient law regulations regarding iot devices. iot devices rules in uk law:  iot devices passwords cannot be rosetted to the default factory settings.  iot device manufacturer must come up with an easy and accessible way to contact them so that any new-found vulnerabilities and weaknesses in their products can be reported, and they have to respond in an appropriate amount of time.  iot device manufacturer must declare minimum time before the device software becomes outdated and needs to be updated. [62]. certification of iot technologies.  european cybersecurity organization came up with the idea to certificate  iot devices are always changing and in need of regular updates that would fix new-found vulnerabilities.  a one-time security certificate is not sufficient thus it has to be adjusted to implement an agile procedure for certificating such systems, that would make sure that its cybersecurity is updated and suited for the system at each point throughout its lifespan. [64]. veracode conducted a study where it inspected six new always-on household iot devices, most of them being controller device for home automation, and remote controllers for switches, garage doors and outlets. they found many vulnerabilities in the devices. one of the results said that hacking the data from home automation controllers and remote controllers for garage doors, criminals could know the pattern of when the user is at home or when the garage doors are opened and closed, and they could use that data to find perfect timing for executing robberies. hacking into a central control device would enable them to set the microphone on so they can hear sensitive information that they can steal, or information they can later use for blackmailing [5]. one of the threats for the iot, that is already happening at this time are shadow devices. basically, employees of a company bring their smart watches or fitness trackers which are iot devices with themselves to the work, and then connect them to the organization’s network, without it department knowing about it. they are usually not aware that those products pose a threat by being unregistered iot device connected to the network. these devices can be used by hackers as a door for entering the network and committing cyber-crimes. infoblox reported that in the previous year 46% of organizations found these shadow devices connected to their corporate network. only 25% haven’t discovered any shadow devices to be connected to their network [22]. if one device has weak points in its security, then it could put the whole network that it is connected to at risk. if that device is hacked, it can be used for ddos attacks. since iot will enable a lot of devices connected to a network, it would mean that hacker would get the opportunity to recruit a big number of targets from one network and use them for attacks [6]. another article claims the same thing, it will be possible to turn many iot devices into botnets and use the massive army of modems, controllers, routers and other devices to execute a ddos attack [13]. another issue are passwords. users are not aware of importance of the security of their devices. most of them just want to buy and use the new technology, but are too lazy to read the user manual and check how to dss vol. 3, 2022, pp.32-49 44 change password or restrict access [21]. researchers have found that default passwords for commercial iot devices could usually be found online in less than half an hour. the intention behind that was probably to make it easier for the user to set up their device, however the issue here is that the hackers can easily find this password too, and since users aren’t too keen on changing the default password, hackers have even more chance to easily take advantage of this “password protected” device. another problem that was found was that devices that were produced by same companies had the same default passwords. the worst scenario is if it is impossible to change the password, because then the whole idea of password doesn’t make any sense [34]. law regulations in uk will make it mandatory for iot devices sold in uk to oblige to these 3 rules: 1. all of the devices will need to have one-of-a-kind passwords that cannot be rosetted to the default factory settings. 2. producers of these devices have to come up with an easy and accessible way to contact them so that any new-found vulnerabilities and weaknesses in their products can be reported, and they have to respond in an appropriate amount of time. 3. producers have to declare minimum time before the device’s software becomes outdated and needs to be updated [62]. one article notes that cost of producing iot devices will decrease, and huge number of the devices will be produced, and more iot devices means more entry points that can be hacked. since update feature can be costly, or impossible due to the resource restrictions, new-found vulnerabilities will not be possible to fix. and if update is obtainable, some companies do not seem to be using encryption when downloading them to the devices, and all of these things pose a serious threat to the security of these devices [12]. another article agrees that it would be a huge threat to the security of device if it cannot receive an update once a vulnerability is identified. another threat is if the data is in the clear text form while being transferred across the cloud, apps and networks. there needs to be a secure encryption for the data transfer to eliminate the possible threats of data stealing and manipulation [63]. one more article agrees that updates for iot devices are one of the possible places for the outsiders to attack, especially since they are very different from the traditional updates that we have now. these updates need to be secured especially since they are usually arranged for a specific time slot and executed throughout the downtime [35]. european cybersecurity organization came up with the idea to certificate iot cybersecurity technologies. iot devices and systems are dynamic, always changing and in need of regular updates that would fix new-found vulnerabilities. due to these characteristics, a one-time security certificate could be of short lifetime, so strategy would be to adjust the certification to these characteristics and implement an agile procedure for certificating such systems, that would make sure that its cybersecurity is updated and suited for the system at each point throughout its lifespan [64]. one of the researchers claims that many household devices will become iot devices, even though they would not need to be. the cost of producing a smart device using a chip will be only a dime. since the cost will be so low, manufacturers will try to turn as many of these devices into smart ones, not for the benefits of users, but so that they can collect data with those chips [37]. some argue that certain types of iot devices should have increased security. such devices are high risk iot devices like ones made for children. vulnerable people like children would not know how to deal with compromised devices, and they probably would not realize that they should report it. another example of high-risk devices would be ovens and thermostats. if attacked, these devices could make more harm than other devices that are not high-risk [65]. 3.5 healthcare iot devices can do a lot of good in healthcare by providing a more efficient diagnosing of the patients and collecting accurate data on patients’ status. however, these devices are also vulnerable to potential cyberattacks which would lead to harming patient’s privacy and breaking physician-patient confidentiality [66]. one of the threats that healthcare faces are attacks on their medical devices, services they provide and their infrastructure, that could affect safety and well-being of their patients, indirectly harming them and possibly causing more health problems, and in worst case scenario, even death [67]. reports have shown that healthcare infrastructure is among the most frequently targeted industries for cyber-attacks. right now, each dss vol. 3, 2022, pp.32-49 45 bed in a hospital is connected to up to 15 different medical devices that can be furtherly interconnected, which is already a relatively big number of entry points. hackers exploit these points to get access to the data, and potentially to harm the patients. when the iiot time comes, the surface available for cyber-attacks will only grow bigger, so healthcare is one of the industries that are going to need cybersecurity the most [68]. one of the reasons why hackers may attack healthcare systems is for financial benefit. it may be generally unknown, but data from the healthcare has bigger worth than other type of data. these illegally obtained medical identities are later utilized to get prescription medication and drugs that can be sold on darknet. medical information occasionally contains the data that can be used for opening new bank accounts or taking out loans [69]. one of the parts of industry 4.0 will be smart connected health. it would lower the price of medical treatments, help to identify any abnormal changes in the patient through analysis of collected data, and generally boost the efficiency of the whole system. however, using iot medical devices can also be dangerous since it could be possible for hackers to attack them and send commands to the device to stop working. this can be very harmful since certain devices, like cardiac devices are crucial for keeping a patient alive [36]. one of the studies has shown that during the period of time 2013-2017, 1512 data breaches happened in the usa, which affected records of 154 415 257 patients. even though the percentage of data breaches caused by hacking incidents was below 25%, it was found that hacking was accountable for almost 85% of the records that were affected. and this happened in the time when iot was not there yet. as healthcare gets to implement the iot technologies in the future, the incidents may get worse, unless the healthcare implements very strong cybersecurity technologies [70]. 4. conclusions development of new technologies is what led to the industry 4.0. through making machines smarter, interconnecting them and combining cyber and physical systems, industry 4.0 will soon face its blooming phase. it will also face some challenges like cybersecurity that will force it to furtherly improve. this paper reviewed selected articles that discuss the cyber threats that industry 4.0 will most likely face, as well as the possible solutions. some of the threats for cybersecurity include lack of awareness, security not being incorporated into the design, poor encryption, default passwords and over-the-air updates. major problems that industry 4.0 will probably face are lack of experts on cybersecurity areas, stealing and manipulation of sensitive data, vulnerable points in the network chain that put the whole network at risk, ddos attacks, as well as other types of cyber-attacks. healthcare may face one of the more serious problems, where the health and safety of the patients might be compromised, beside their data that may be stolen. apart from these challenges, there are also some good news and solutions for some of these problems. some of them are layered security approach, stronger encryption, more frequent authentication and authorization of devices, as well as prevention, detection and response mechanisms regarding cyber-attacks. suggestions include analyzing the system and detecting its vulnerable points and adding extra security around those. through creating cyber-attack scenarios, companies will be able to identify possible breaches and find a way to stop them before they happen. and lastly, implementing law regulations that would guard the satisfactory security levels in the devices and certificating the cybersecurity software. one of the possible directions for the future research would 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[70] j. g. ronquillo et al., “brief communication health it, hacking, and cybersecurity: national trends in data breaches of protected health information,” doi: 10.1093/jamiaopen/ooy019. dss vol. 3, 2022, pp.32-49 49 [71] r. m. blank et al., “information security continuous monitoring (iscm) for federal information systems and organizations,” 2011. microsoft word 46-64_270 (online) issn 2744-1741 defense and security studies original research vol. 5, no. 1, 2024, pp. 46-64 https://doi.org/10.37868/dss.v5.id270 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 46 the influence of projectile impact velocity and target characteristics on the terminal ballistics parameters of small-caliber projectile faris memić1*, alan ćatović2 1 defense technologies department, mechanical engineering faculty, university of sarajevo, bosnia and herzegovina 2 defense technologies department, mechanical engineering faculty, university of sarajevo, bosnia and herzegovina *corresponding author e-mail: farismemic04@gmail.com received: jun. 5, 2024 revised: jul. 18, 2024 accepted: jul. 20, 2024 online: jul. 25, 2024 abstract the study examines the results of numerical simulations of the penetration of a 7,62 mm x 63, ap, m2 projectile through a target. model validation involved a numerical simulation of 7,62mm x 63, ap, m2 projectile penetration through an aa5083h116 target, for which experimental results were available in the literature. the results of the numerical simulation were used for regression analysis to calibrate the recht-ipson model for the given projectile. furthermore, penetration analyses of 7,62 mm x 63, ap, m2 projectiles through various target materials were performed at consistent projectile velocities and mesh sizes. as expected, bainitic steels exhibited the highest resilience, demonstrating that increased material hardness and tensile strength correlate with enhanced projectile penetration resistance. © the author 2024. published by arda. keywords: numerical simulation, penetration, 7,62mm x 63, ap, m2, ansys, autodyn 1. introduction projectile penetration through a target is a highly significant research topic for applications in defense technologies (i.e. ref [32]). research on projectile penetration is crucial for understanding the fundamental mechanisms of protection against projectile impacts and armor design, as well as for enhancing the effectiveness of munitions against specific types of targets. there are three methods for analyzing projectile penetration: experimental, analytical, and numerical simulation methods. the experimental method is the most reliable, but it is also the most expensive and time-consuming. a drawback of the experimental method is that the results cannot be extrapolated to different ranges of variables beyond those used in the tests. the analytical method can be used to perform certain analyses that yield usable results, such as the rechtipson method. however, due to the complexity of modern systems, the analytical method is primarily used to gain insight into the nature of the penetration process. it can also be employed prior to conducting experiments; for example, a preliminary analytical approach can be used to establish a starting point and reduce the total number of experiments needed. parametric analytical analysis is useful if the appropriate constants for the given target material and projectile type are known. dss vol. 5, no. 1, 2024, pp. 46-64 47 the numerical simulation method, which will be used in this study, has the capability to handle very complex geometries without any difficulties. depending on the complexity of the material models used, results can range from the accuracy level of analytical models to that of experimental models. by setting up an adequate material model, any penetration simulation can be conducted seamlessly, yielding reliable results. parameters such as impact velocity, target thickness, and impact angle (3d simulation is required for impact angle) can be varied as desired. given the current advancements in hardware and software, numerical simulations can be conducted very quickly and at a much lower cost than experimental methods, while still providing highaccuracy results (provided the conditions for good accuracy are met, as outlined below). accuracy depends on many parameters: the accuracy of the material model and constants in the models, the numerical model (mesh, solver, initial and boundary conditions), the type of simulation software used, etc. 2. data on 7.62mm x 63, ap, m2 ammunition (usa: .30, ap, m2) and the weapons used with this type of ammunition the american .30-06 ap, m2 / 7.62 mm x 63 ammunition was introduced in 1906 as an evolution of the us army’s short-lived use of the .30-03 cartridge, which was originally adopted in 1903 with a round-nosed bullet. the .30-06 cartridge has a slightly different case than the .30-03 and, more importantly, features an ogive-shaped projectile, providing significantly better aerodynamic performance. the 7.62 mm x 63 ap, m2 ammunition has a projectile mass of 10.8 grams, a muzzle velocity of 830 m/s, and a muzzle energy of 3730 j [1]. this ammunition is used against lightly armored vehicles, protective shelters, and infantry [2]. the basic data on this ammunition is provided in table 1. table 1. the basic data on ammunition .30-06, ap, m2 [3] dodac 1305-a202 uno proper shipping name cartridges for weapons, inert projectile mass (g) 27,5 length (mm) 84,8 mm primer impact propellant type wc 852 propellant weight (g) 3,6 projectile weight (g) 10,8 performance chamber pressure (mpa) 372 velocity (m/s) 827,5; at 23,8 m from muzzle shipping and storage data quantity-distance class/scg 1.4s storage code class v dot shipping class c figure 1 shows the 7.62mm x 63 (.30-06) ap, m2 ammunition and its cross-section. in the cross-section, the components of the ammunition can be seen: the brass jacket and case, the lead cap, and the steel core. the tip of the projectile is painted black to indicate armor-piercing ammunition. ammunition 7.62mm x 63, ap, m2 is fired from 7.62 mm machine guns, models: m37, m1919a4 and m1919a6, and a .30 caliber rifle, m1 [3]. in military service, the 30-06 was used in the bolt-action m1903 springfield rifle, the bolt-action m1917 enfield rifle, the semi-automatic m1 garand rifle, the semiautomatic m1941 johnson rifle, the famage mauser, the browning automatic rifle (bar), and numerous machine guns, including the m1917and m1919 series [4]. dss vol. 5, no. 1, 2024, pp. 46-64 48 figure 1. ammunition .30-06, ap, m2 3. numerical simulations 3.1. basics of the autodyn software the ansys workbench platform enables interaction with ansys solvers. ansys workbench is composed of different modules, eg: explicit dynamics, meshing, autodyn, etc. in ansys solvers, the terms "implicit" and "explicit" refer to two types of time integration methods used to perform dynamic simulations. explicit time integration is more stable, but the simulation takes longer due to the small time-step (due to the high velocities, fine mesh, and high velocity of sound that are used in the materials) and is more efficient for simulations involving [5]:  spreading of the shock wave,  large deformations and stretching,  non-linear behavior of material,  complex contact between certain components  fragmentation of material, etc. explicit methods calculate the state of the system in the next step based on the current state of the system, while implicit methods try to arrive at a solution by solving an equation involving the current state and the state of the system in the next step. implicit methods require more computer resources and are much more difficult to implement. compared to explicit, implicit methods have better stability, so larger time steps can be used with them. however, implicit methods require solving a large system of coupled equations for each time step, which significantly complicates the problem [5]. a typical application of the explicit dynamics module includes i.e. [5]:  simulation of an object falling from a height  impact and penetration process  fragmentation  explosions, etc. dss vol. 5, no. 1, 2024, pp. 46-64 49 the autodyn programs are general-purpose engineering software packages that use finite difference, finite volume, and finite element techniques to solve a wide variety of non-linear problems in solid, fluid, and gas dynamics. autodyn has a wide range of uses, eg: street explosions, building explosions, mine explosions, improvised explosive devices (ieds), mining explosions, warhead design (cumulative charges), missile/warhead impact, aircraft impact, body armor, drop tests, destruction, etc. autodyn can be characterized as "many codes in one", and includes both structural mechanics and fluid mechanics regimes. each of these "codes" in autodyn represents a specific numerical solver, for example [6]:  lagrange processor for modeling solid continua and structures  euler processors for modeling fluids, gases, and large distortion. these processors include first-order and second-order accurate schemes.  ale (arbitrary lagrange euler) processor for specialized flow models  shell processor for modeling thin structural elements  sph (smooth particle hydrodynamics). compared to the eulerian approach, discussed below, the lagrange formulation tends to be faster computationally as no transport of material through the mesh needs to be calculated. moreover, material interfaces, free surfaces, and history-dependent material behavior are generally easier to follow in the lagrange framework. the major disadvantage of lagrange is that if excessive material movement occurs, the numerical mesh may become highly distorted leading to an inaccurate and inefficient solution. further, this may ultimately lead to a termination of the calculation [6]. the calculations performed at each incremental time step (or cycle) in the lagrange solver are shown schematically in figure 2. figure 2. lagrange computation cycle [6,31] autodyn utilizes the differential equations governing unsteady material dynamic motion to express the local conservation of mass, momentum, and energy. in order to obtain a complete solution, in addition to appropriate initial and boundary conditions, it is necessary to define a further relation between the flow variables. the relations between the hydrostatic pressure, the local density (or specific volume), and the local specific energy (or temperature) are known as an equation of state [6]. the rankine-hugoniot equations for the shock jump conditions can be regarded as defining a relation between any pair of the variables ρ, p, e, up, and u. here, u is the velocity of the shock wave in the material, and up is the velocity of the particles of the material. in many dynamic experiments making measurements of up and u, it has been found that for most solids and many liquids over a wide range of pressure, there is an empirical linear relationship between these two variables, viz. [6]: 𝑈 = 𝑐 + 𝑠𝑢 (1) where c0 is the speed of sound, and s is an empirically determined constant. dss vol. 5, no. 1, 2024, pp. 46-64 50 autodyn uses the mie-gruneisen form of the equation of state, based on the so-called hugoniot shock (an empirical curve showing the dependence of u(up), p(up), or p(v)), in the form [6]: 𝑝 = 𝑝 + γ𝜌(𝑒 − 𝑒 ) (2) where γ is the gruneisen constant (for most materials it has a value of 1.25 ± 0.75). also applies: 𝑝 = 𝜌 𝑐 𝜇(1 + 𝜇) [1 − (𝑠 − 1)𝜇] (3) 𝑒 = 1 2 𝑝 𝜌 𝜇 1 + 𝜇 (4) the johnson-cook model is a constitutive model that aims to model the strength behavior of materials subjected to large strains, high strain rates, and high temperatures. such behavior might arise in problems of intense impulsive loading due to high-velocity impact and explosive detonation. the model defines the yield stress σy as [6]: 𝜎 = 𝐴 + 𝐵𝜀 1 + 𝐶 log 𝜀 ̇ [1 − 𝑇 ] (5) where: εp – effective plastic strain, 𝜀 ̇ – normalized effective plastic strain rate (the ratio of the current strain rate to the reference strain rate 𝜀 ̇ ), th – homologous temperature (t-troom)/(tmelt-troom). the five material constants are a, b, c, n, and m. johnson-cook failure model is also an empirical model based on the tests with several metallic materials. it implements the effects of temperature softening and strain rate hardening. the basic form of the model, using the damage accumulation, can be seen in equation [7]: 𝐷 = ∆𝜀 𝜀 (6) where: d – damage, ∆ε increment of equivalent plastic strain during 1 integration cycle, εf failure strain failure strain is defined as follows: 𝜀 = 𝐷 + 𝐷 e( ∗) 1 + 𝐷 ln 𝜀̇ [1 + 𝐷 𝑇 ] (7) where: d1-d5 – material constants, σ* the ratio of stress to equivalent stress, 𝜀̇ normalized rate of plastic deformation, 𝑇 homologous temperature. when d in equation (7) becomes unity, failure occurs and the element is removed (eroded) from the computational grid [7]. although autodyn can calculate with both lagrangian and eulerian subgrids it may sometimes be the case that materials have to be defined on lagrangian subgrids even though it is clear that these materials will be subjected to very large distortions arising from the gross motion of the lagrange grid [6]. during the subsequent calculation some of these lagrangian cells can become grossly distorted and, unless some remedial action is taken, can seriously impair the progress of the calculation. therefore, procedures have been incorporated into autodyn (both 2-d and 3-d) to remove such lagrangian cells from the calculation if a pre-defined strain (either instantaneous geometric strain, incremental geometric strain, or effective plastic strain) exceeds a specified limit. when a cell is removed from the calculation process in this way the mass dss vol. 5, no. 1, 2024, pp. 46-64 51 within the cell can either be discarded or distributed to the corner nodes of the cell. if the mass is retained, conservation of inertia and spatial continuity of inertia are maintained. however, the compressive strength and internal energy of the material within the cell are lost whether or not the mass is retained. this discard procedure is known as erosion [6]. 3.2. the numerical model validation validation of the numerical model was performed using available experimental data (t. borvik [8]) from which data on the dimensions and material of the target, and the material of the projectile parts were also collected. a target of dimensions 150 mm x 150 mm and thickness 20 mm, aa5083h116, was used, for which experimental data are available in [8]. the target and the 7.62mm x 63 projectile were first modeled in the "solidworks" software (figure 3) and then exported as a .iges file for insertion into the ansys workbench explicit dynamics module (figure 4). a 2d model, axial symmetry, was used in the calculation, which was made on the basis of a 1/4 3d model in solidworks and using options in geometry modeler. figure 3. layout of the 1/4 3d model in solidworks figure 4. layout of the 2d model of projectile 7,62mm x 63 and target in ansys workbench explicit dynamics module dss vol. 5, no. 1, 2024, pp. 46-64 52 in order to perform a sensitivity analysis of the numerical model grid, a 2d axisymmetric model with several different grids was discretized using the lagrange solver (figure 5). a comparison of the results was made for the following grids (mech element size): 0.1; 0.15; 0.2; 0.25; 0.3; 0.35; 0.4; 0.45 and 0.5 mm. the mesh was the same size for both the projectile elements and the target. the condition of impact velocity in the y-axis direction (in the direction of penetration of the projectile through the target) of 822.4 m/s was set as stated in the reference [8]. also, the target is fixed on the outer edge parallel to the axis of symmetry. figure 5. layout of the 0,1 mm grid placed to projectile and target projectile material models (jacket, cup, core, and lead filling) were collected from the ansys autodyn library and combined with additional literature data [8]. the material models for the target were taken from the ansys autodyn library in combination with additional data from the literature [9]. for the plate that was used as a target (aluminum alloy aa5083h116), the gruneisen shock equation of state with the following constants was used: γ=1,97; ρ=2700 kg/m3; c0=5340 m/s and s=1,4. also, the johnsoncook model (strength model) was used, with the following constants: a=167 mpa; b=596 mpa; n=0,551; c=0,001 and m=0,859. the material failure model (johnson-cook) was also used on the target, with the following constants: d1=0,0261; d2=0,263; d3=-0,349; d4=0,147; d5=16,8. the projectile is composed of a steel core, a brass jacket and cup, and a lead tip. no failure model was used for the projectile parts. the johnson-cook strength model was used, the constants of the model are given in table 2, as well as other material properties in table 3. table 2. johnson-cook constants for materials of projectile parts material a (mpa) b (mpa) n c ε0* (1/s) m tm (k) steel (core) 1200 50000 1 0 0,0005 1 1800 lead (tip) 24 300 1 0,1 0,0005 1 760 brass (jacket and cup) 206 505 0,42 0,01 0,0005 1,68 1189 dss vol. 5, no. 1, 2024, pp. 46-64 53 table 3. the main mechanical characteristics of the materials of projectile parts material density (kg/m3) young’s modulus (mpa) poisson’s ratio bulk modulus (pa) shear modulus (pa) specific heat capacity (j/kgk) steel (core) 7850 210000 0,33 2,0588∙1011 7,8947∙1010 452 lead (tip) 10660 1000 0,42 2,0833∙109 3,5211∙108 124 brass (jacket and cup) 8520 115000 0,31 1,0088∙1011 4,3893∙1010 385 in the reference [8], the initial velocity (vi = 822.4 m/s) and the experimentally obtained exit velocity (vr = 694.3 m/s) are given for the penetration test of the aa5083-h116 target material. the results of exit velocities obtained by numerical simulations as part of this validation are compared with the given projectile exit velocity obtained in the test. the relevant exit velocity is taken from the projectile element at the bottom of the projectile core because these elements are mostly used in the literature. exit velocities in the period from 90 to 100 μs for different grids from 0.1 to 0.5 mm were analyzed. because the values of the obtained exit velocities fluctuate around some mean value, the mean values of the velocity for a given bottom element and for each grid, in the time period from 90 to 100 μs (when the projectile leaves the target), were calculated. figure 6 shows a diagram showing that the exit velocity settles at around 705.8 m/s, and considering that the 0.1 mm mesh has approximately the same velocity value, the 0.2 mm mesh gives sufficiently accurate simulation results. also, the numerical simulation itself with a mesh of 0.2 mm takes much less time compared to a mesh of 0.1 mm. by comparing the exit velocity obtained by numerical simulation for a 0.2 mm mesh with the exit velocity obtained by the test in the literature [8], a relative error of 1.65% is obtained, which is a satisfactory result. considering the small relative error, the 0.2 mm grid seems satisfactory and is adopted for further analysis in the paper. the appearance of the penetration process of ap 7.62mm x 63 projectile at a time-frame of 50 μs in the ansys workbench explicit dynamics module is shown in figure 7, and in figure 8 at a time-frame of 100 μs. qualitatively, the penetration simulation process is shown to resemble the penetration process presented also in the paper [8]. figure 6. display of the relationship between projectile exit velocity and mesh size and polynomial regression curve y = -691.48x3 + 433.49x2 87.543x + 711.09 r² = 0.8555 650.0 660.0 670.0 680.0 690.0 700.0 710.0 720.0 0 0.1 0.2 0.3 0.4 0.5 0.6 ve lo ci ty (m /s ) mesh size (mm) vaverage in the period 90-100 microseconds poly. (vaverage in the period 90-100 microseconds) dss vol. 5, no. 1, 2024, pp. 46-64 54 figure 7. display of the numerical simulation of the penetration of a 7.62mm x 63 caliber projectile through a target at the moment when the projectile is in the target figure 8. display of the numerical simulation of the penetration of a 7.62mm x 63 projectile through the target at the moment when the projectile passed through the target figure 7. and figure 8. shows that the core of the 7.62mm x 63 projectile remained almost undamaged during the penetration of the target. this is also recored in ref. [8] that served in validation process. 3.3. influence of projectile impact velocity and target material on the process of projectile penetration in this sub-chapter 3.3.1, an analysis of the influence of the variation in the impact velocity of the projectile on the exit velocity of the projectile was performed. the analysis was performed for the 0.2 mm mesh size (which was adopted earlier as the reference in the numerical model validation process) and the aa5083h116 target for different projectile impact velocities. dss vol. 5, no. 1, 2024, pp. 46-64 55 in the sub-chapter 3.3.2, the influence of the variation in the target material on the projectile penetration process was performed. the analysis was performed also for a mesh size of 0.2 mm and a projectile impact velocity of 822.4 m/s for different target materials. 3.3.1. the effect of changing the impact velocity of the projectile in this part of the research, numerical simulations of the penetration of the 7.62mm x 63 projectile through the aa5083h116 target were carried out for different impact velocities of the projectile at a mesh size of 0.2 mm. the projectile and target materials, as well as the material models used, are the same as in the validation of the numerical model. the projectile and target geometry are also the same. for an impact velocity of 400 m/s, the projectile does not pass through the target. the ballistic limit velocity is the input velocity at which the exit velocity obtained by numerical simulation is equal to 0. this ballistic limit velocity is obtained as the average velocity between the highest velocity of the projectile that does not penetrate the target and the lowest velocity of the projectile that completely passes through the target. in our case, the ballistic limit velocity was vbl = 401 m/s. after estimating the ballistic limit velocity, the calculation for the exit velocity of the projectile corresponding to the given input velocity was also carried out using the recht–ipson model. output velocities were calculated based on the following empirical model originally proposed by recht and ipson [9]: 𝑣 = 𝑎 ∙ (𝑣 − 𝑣 ) (8) where: vi – impact velocity, vr – exit velocity, vbl – ballistic limit velocity, a and p – recht constants of the model. regression analysis (of data obtained by simulations) was used to determine the parameters a and p from the recht-ipson model as accurately as possible. the determination of these parameters was performed using the "matlab" program ("curve fitting tool" option, the values of the projectile's impact and exit velocity obtained by simulation are used). figure 9 shows a graph of projectile exit velocity versus projectile impact velocity for numerical simulations and the recht-ipson model with obtained constants. figure 9. diagram of exit velocity of the projectile as a function of projectile impact velocity (simulation results and recht-ipson curve) 0 100 200 300 400 500 600 700 800 350 450 550 650 750 850 ex it ve lo ci ty (m /s ) impact velocity (m/s) recht-ipson model simulation dss vol. 5, no. 1, 2024, pp. 46-64 56 by using the equation of the recht-ipson model curve whose constants are obtained by regression based on the results of the numerical simulation, the output velocity of the projectile can be determined for different values of the input velocity of the projectile without starting the simulation. this model is most often used for cases of projectile impact at a normal angle to a thin target. the disadvantage of this model is that in order to obtain the constants, experimental testing or numerical simulation must be carried out in order to obtain the constants by regression of the test/simulation results. 3.3.2. the effect of changing the target material numerical simulations in this part of the research were performed for the same conditions as in the previous chapters. the material of the projectile parts is also unchanged, the only variation is in the 20 mm thick target material. it is assumed that the equation of state for all steels is the same and the constants of this equation are listed in table 4. tables 5 and 6 lists the johnson-cook strength model constants and fracture model constants for various target materials. table 4. coefficients of the gruneisen shock equation of state for the target material [10] material density (g/cm3) gruniesen coefficient c0 (m/s) s steel/iron 7,85 1,93 4570 1,49 table 5. johnson-cook strength model constants for various target materials material a (mpa) b (mpa) n c m steel 4340 [autodyn library] 792 510 0,26 0,014 1,03 armox 500t [11] 1372,4 835 0,2467 0,0617 0,84 mild steel [11] 304,3 422 0,345 0,0156 0,87 rha steel [12] 1193 500 0,676 0,00435 1,17 weldox 460e steel [13] 490 807 0,73 0,012 0,94 weldox 700e steel [14] 859 329 0,579 0,0115 1,071 weldox 900e steel [4] 992 364 0,568 0,0087 1,131 iron armco [autodyn library] 175 380 0,32 0,06 0,55 bainite steel [15] 1517 1575 0,35 0,01 1 nanos-ba steel [12] 1303 1420 0,195 0,075 1,17 steel tenax [16] 1440 492 0,24 0,011 1,03 steel 2p [16] 1210 773 0,26 0,014 1,03 table 6. johnson-cook failure model constants for different target materials material d1 d2 d3 d4 d5 steel 4340 [autodyn library] 0,05 3,44 -2,12 0,002 0,61 armox 500t [11] 0,04289 2,1521 -2,7575 -0,0066 0,86 mild steel [11] 0,1152 1,0116 -1,7684 -0,05279 0,5262 rha steel [12] 0,21 7,2 -5,44 0 0 weldox 460e steel [13] 0,0705 1,732 -0,54 -0,0123 0 weldox 700e steel [14] 0,361 4,768 -5,107 -0,0013 1,333 weldox 900e steel [14] 0,294 5,149 -5,583 0,0023 0,951 iron armco [autodyn library] -2,2 5,43 -0,47 0,016 0,63 bainite steel [15] 0,047 0,165 -2,7 0 0 nanos-ba steel [12] 0,047 0,165 -2,7 0 0 steel tenax [16] 0 1,07 -1,22 0,000016 0,63 steel 2p [16] 0,1 0,93 -1,08 0,000014 0,65 numerical simulation results, i.e. the penetration process of the 7.62mm x 63 projectile through targets made of different steels at a projectile impact velocity of 822.4 m/s and a mesh size of 0.2 mm are shown in figure 10. the material of the target in the figure is given in the legend and is marked in blue. dss vol. 5, no. 1, 2024, pp. 46-64 57 figure 10a. numerical simulation results: penetration process of projectile 7.62mm x 63 through targets made of different steels at projectile impact velocity 822.4 m/s and mesh size 0.2 mm dss vol. 5, no. 1, 2024, pp. 46-64 58 figure 10b. numerical simulation results: penetration process of projectile 7.62mm x 63 through targets made of different steels at projectile impact velocity 822.4 m/s and mesh size 0.2 mm – continued dss vol. 5, no. 1, 2024, pp. 46-64 59 figure 10c. numerical simulation results: penetration process of projectile 7.62mm x 63 through targets made of different steels at projectile impact velocity 822.4 m/s and mesh size 0.2 mm – continued table 7 shows the penetration depths of the 7.62mm x 63 projectile through targets made of different steels at an impact velocity of 822.4 m/s. in figures 10a-c and table 7, it can be noted that the most durable steels are bainite steels (nanos-ba steel and bainite) as well as armox 500t steel. dss vol. 5, no. 1, 2024, pp. 46-64 60 the 2p and tenax steels also showed relatively good performance against the 7.6 2mm x 63 projectile, retaining the projectile in the target after penetrating a little more than half the thickness of the target. rha and 4340 steels did not perform as well, where the 7.62 mm x 63 projectile penetrated almost the entire target, but remained stuck the target. they have shown better durability than the materials listed below. weldox 460e, weldox 700e, iron armco, and mild steel showed lower effectiveness than the previous steels in penetration of the 7.62mm x 63 projectile at 822.4 m/s and the projectile completely penetrated targets with these materials. mild steel showed the weakest performance as the projectile completely exited the target, while with the materials mentioned before (bainite steels, armox 500t, 2p, 4340 and tenax steels, rha, weldox 700e and weldox 900e) the projectile remained stuck in the target. table 7. the penetration depth of the projectile 7.62 mm x 63 through a target made of different steels at a projectile impact velocity of 822.4 m/s target material penetration depth (mm) nanos-ba steel 4,5 armox 500t 7,7 bainite steel 9 steel 2p 11 steel tenax 12 steel 4340 18 rha 18 weldox 900e 19,5 mild steel 20 (perforation) iron armco 20 (perforation) weldox 460e 20 (perforation) weldox 700e 20 the data required for the analysis of the influence of mechanical characteristics on the penetration depth of the 7.62x63 mm projectile through the target are set out in table 8. the hardness of a material is a measure of the material’s resistance to indentation, abrasion, and wear. for metals, the hardness of a material can be related to a material’s uts (ultimate tensile strength) with a linear relationship, which is shown in the diagram of tensile strength as a function of hardness (figure 11). in the diagram in figure 11, approximately mean values are used for parameters whose exact value is not known, but the range of values is known. it can be seen in table 8 that a material with a higher hardness has a higher tensile strength. increasing the hardness of steel leads to an increase in the ballistic protection of armor materials. high hardness contributes the most to the reduction of penetration depth. this is evident in materials such as armox 500t and bainite steel, which have relatively small penetration depths. materials with relatively high hardness (eg weldox 900e) resist projectile penetration better than materials with lower hardness (eg iron armco). this can be seen from the fact that although the weldox 900e and weldox 700e steels have approximately the same penetration depth of 20 mm, the projectile in these cases failed to completely penetrate them, while it completely penetrated the softer iron armco and weldox 460e steels. dss vol. 5, no. 1, 2024, pp. 46-64 61 table 8. mechanical properties of the target material and penetration depth of the 7.62 mm x 63 projectile material hardness (bhn) tensile strength (mpa) penetration depth (mm) nanos-ba steel 590-640 [18] 1800-2000 [18] 4,5 armox 500t 480-540 [10] 1450-1800 [10] 7,7 bainite steel 373-627 [20] 1770-2200 [19] 9 steel 4340 321 [21] 1100 [21] 18 rha steel 302-400 [22] 1170 [23] 18 mild steel 105 [24] 365 [24] 20 (perforation) iron armco 74-83 [25] 290 [25] 20 (perforation) weldox 460e 171-181 [26] 530-720 [17] 20 (perforation) weldox 700e 210-240 [27] 780-930 [27] 20 weldox 900e 280-330 [28] 940-1100 [29] 19,5 figure 11. diagram of tensile strength as a function of hardness high strength and ductility are assumed to be vital parameters in order to absorb energy during structural impact [14]. ductility is the ability of a material to withstand plastic deformation without breaking. the more a material is capable of withstanding greater deformation without brittle fracture, the more ductile the material is. for materials that are subjected to relatively high strain rates (when compared to quasi-static values), their strengths can change and, for most materials, increase markedly. generally speaking, metals will get stronger but less ductile at elevated strain rates, but unlike some non-metals, their stiffness is relatively unaffected by increased deformation rates. the reason for the increased strength with strain rate is due to complex microstructural behavior that is dependent on the nature of the material (at high deformation rates, dislocations accumulate within the material structure and the material hardens) [17]. in addition to hardness and ductility, the mechanical properties to pay attention to are also yield strength, tensile strength, and toughness. the area under the curve on a hooke diagram (stress diagram) is a measure of the strain energy absorbed per unit volume, v, and is an indication of the toughness of the material. for an armor designer, toughness is a desirable property because a tough material requires more energy to cause fracture. high tensile strength and yield strength allow steel to resist deformation and maintain structural integrity under high stress [17]. a material such as rha steel, while not the hardest of the given steels, has a high tensile strength, which helps to better absorb and dissipate projectile energy. it is noticeable that the steels with the highest resistance to projectile penetration are the steels with the highest hardness and tensile strength. because of this, targets such as mild steel and iron armco suffer full penetration compared to bainitic steels and armox 500t steel. the iron-armco has 7-8 times lower hardness than nanosba steel and 5 times lower tensile strength. y = 3.1231x + 76.429 r² = 0.9857 0 500 1000 1500 2000 2500 0 100 200 300 400 500 600 700 te ns ile s tr en gt h [m pa ] hardness [hb] dss vol. 5, no. 1, 2024, pp. 46-64 62 the diagram of penetration depth as a function of tensile strength in figure 12 was obtained on the basis of data from table 8, where approximately mean values were used for material properties whose exact value is not known, but the range of values is known. looking at the plot of penetration depth as a function of tensile strength, it can be concluded that tensile strength is a good indicator of armor performance. it can be clearly seen that the penetration depth decreases with increasing tensile strength, with a small deviation for the armox 500t steel. the diagram of penetration depth as a function of hardness (figure 13) was obtained in the same way as the diagram from figure 12. on the diagram of the depth of penetration as a function of hardness, as well as on the diagram from figure 12, it is seen that increasing the hardness decreases the depth of penetration. similar results and conclusions about the influence of tensile strength and hardness are given in reference [30]. figure 12. diagram of penetration depth as a function of tensile strength figure 13. diagram of penetration depth as a function of hardness 4. conclusions the study evaluates the penetration capability of small-caliber projectiles using numerical simulation methods. numerical simulations were performed using ansys autodyn software, simulating the penetration of a 7.62mm x 63, ap, m2 projectile through targets made of different materials. for model validation, reference [8] was used to confirm the model's validity, as the results of the projectile's exit velocity from the numerical nanos-ba steel armox500t steel bainite steel 4340 steel rha steel mild steel iron armco weldox460e steel weldox700e steel weldox900e steel 0 5 10 15 20 25 0 500 1000 1500 2000 pe ne tr at io n de pt h [m m ] tensile strength [mpa] nanos-ba steel armox500t steel bainite steel 4340 steel rha steel mild steel iron armco weldox460e steel weldox700e steel weldox900e steel 0 5 10 15 20 25 0 100 200 300 400 500 600 700 pe ne tr at io n de pt h [m m ] hardness [hb] dss vol. 5, no. 1, 2024, pp. 46-64 63 simulation closely matched the experimental results reported in the literature [8] (a relative error of 1.65% was obtained). after validating the model, an analysis was conducted on the impact of varying the projectile's input velocity and changing the target material for the same input velocity. the projectile exit velocities obtained from numerical simulations showed good agreement with the exit velocities calculated using the recht-ipson model. it was also observed, as expected, that the reduction in the projectile's exit velocity as a function of impact velocity is nearly linear. the projectile's exit velocity can be determined for different input velocities without running additional simulations by using the recht-ipson model. material hardness is a measure of a material's resistance to indentation, abrasion, and wear, and can be correlated with its maximum tensile strength through a linear relationship. it is assumed that high strength and ductility are key parameters for the target material's ability to absorb energy upon impact. for armor designers, toughness is also a desirable property, as a tough material requires more energy to fracture. the analysis of changing the target material for the same input projectile velocity (822.4 m/s) showed that bainitic steels (with the highest hardness) were the most resilient, followed by armox 500t steel. examining the effect of changing the target material for the same input projectile velocity, it can be concluded that ballistic protection can be increased by increasing the material's hardness and tensile strength, with a clear reduction in penetration depth as the hardness and tensile strength of the target material increase. for future work, further research is recommended to expand the analysis of the influence of various factors on projectile penetration. special attention should be paid to variations in projectile and target geometry, as well as the possibilities for optimizing materials to increase resistance to penetration. additionally, research should encompass a wider range of calibers and types of projectiles to gain a more comprehensive understanding of penetration dynamics in different situations. the study could be expanded by using multi-layer targets and varying target thickness, allowing for the measurement of maximum projectile penetration depths. investing in computer equipment would enable the performance of 3d numerical simulations, facilitating high-quality testing of projectile impacts on angled targets set at specific angles relative to the direction of fire. investing in computer equipment could also save money compared to the costs required for conducting experimental tests. in experimental studies, systems such as high-speed cameras could be implemented where feasible. funding information no funding was received from any financial organization to conduct this research. declaration of competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. references [1] https://modernfirearms.net/en/cartridge/30-06-us-306-7-62x63mm-30-cal-1906/ [2] nij standard-0101.06:200 ballistic resistance of body armor, u.s. department of justice office of justice programs, washington, usa. [3] army ammunition data sheets small caliber ammunition fsc 1305 tm-43-0001-27 headquarters, department of the army, april 1994. [4] https://www.goofygoatgifts.com/product-page/30-06-bullet-pendant [5] a. ćatović, numerical simulations in ballistics, mechanical engineering faculty, sarajevo, 2024. [6] autodyn® – explicit software for nonlinear dynamics, theory manual – revision 4.3., 2005. [7] g. ozturk, “numerical and experimental investigation of perforation of st-37 steel plates by oblique impact [ms thesis]”, the graduate of school of natural and applied sciences of middle east technical university, 2010. [8] t. borvik, l. olovsson, s. dey, m. langseth, “normal and oblique impact of small arms bullets on aa6082-t4 aluminum protective plates”, international journal of impact engineering, vol 38, pp. 577589, 2011. dss vol. 5, no. 1, 2024, pp. 46-64 64 [9] m. a. iqbal, k. senthil, p. bhargava, n. k. gupta, “the characterization and ballistic evaluation of mild steel”, international journal of impact engineering, vol. 78, pp. 98-113, 2015. [10] a. mubashar, e. uddin, n. arif, s. w. ul haq, m. chowdhury, “ballistic response of 12.7 mm armour piercing projectile against perforated armour developed from structural steel”, proceedings of the institution of mechanical engineers, part l: journal of materials: design and applications, vol. 233, issue 10, october 2018. [11] k. senthil, m. a. iqbal, s. rupali, “influence of impactor nature, mass, size and shape on ballistic resistance of mild steel and armox 500 t steel”, international journal of protective structures, pp. 1-24, 2018. 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[29] weldox 900 datasheet, ssab oxelösund ab, version 2005-10-15 [30] k. l. phelps, “material properties affecting the penetration of metal targets by copper linear shaped charges [ms thesis]”, missouri university of science and technology, 2016. [31] a. catovic, “research of influence of different shaped charge liner materials on penetration depth using numerical simulations”, periodicals of engineering and natural sciences, vol 11, no. 4, pp. 1-26, 2023. [32] a. catovic, “estimation of terminal ballistics parameters for several 7.62×51 mm projectiles using numerical simulations”, the journal of defense modeling and simulation: applications, methodology, technology, 2024. microsoft word 108-114_274 (online) issn 2744-1741 defense and security studies original research vol. 5, no. 2, 2024, pp. 108-114 https://doi.org/10.37868/dss.v5.id274 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 108 security considerations for smartphone devices almina musinbegovic1, harun alijagic1, amer hrnjic1, ali abd almisreb1* 1 computer sciences, faculty of engineering and natural sciences, international university of sarajevo, bosnia and herzegovina *corresponding author e-mail: aalmisreb@ius.edu.ba received: nov. 6, 2024 revised: dec. 8, 2024 accepted: dec. 10, 2024 online: dec 15, 2024 abstract in the paper, the ways in which smartphone devices are designed to be secure are investigated. different approaches were examined for windows, android, and alike, as well as diving into the three security layers or areas of security. the first layer investigated was a “physical” device protection which involves the protection of the device and the data on it in case the device was stolen by not allowing anyone to gain access to the device, and locking its content. the second protection of the data examined was not allowing applications on the device access to corporate and personal data. the last layer of the protection investigated was in-app information being leaked and otherwise used. security objectives and mechanisms were also visited in the paper. a literature review on the subject is provided. © the author 2024. published by arda. keywords: computer network reliability surveillance, communication system security, smartphone protection 1. introduction it is important to point out why smartphone security is so important. we take for granted the technology we have and rarely worry about its communication system security. the pictures we have stored on our devices as well as various passwords or bank card details are all vulnerable to all kinds of hacks. not to mention the soft version of hacks which would be the constant attempts by our apps and companies to gather as much information about us as possible. be that directly or indirectly our personal information is always under surveillance. although we might not experience being hacked ourselves one can see the liability carried by companies if they are ever undermined by hackers or thieves, as this would reflect poorly on their computer network reliability. in essence, companies have a vested interest in protecting their users and invest a lot of resources to build their devices/software to be secure. in order for us to know what exact problems should be considered we must first look at how users use their mobile devices. which tasks do they want to perform and how they perceive the security and privacy of these devices? are they comfortable using them for sensitive tasks? how do mobile devices compare with laptop and desktop devices in terms of privacy and security? knowing what users consider useful and necessary in mobile devices allows us to better understand and prevent mistakes from happening. a smartphone is a mobile phone that is created to offer new advanced features that are useful for its users. in a short time, it became the most useful phone in the world because of its advanced computing ability and dss vol. 5, no.2, 2024, pp. 108-114 109 connectivity. one of the best features of a smartphone is installing and running more advanced applications based on a specific platform by using a wi-fi internet connection [1][2]. the usage of smartphones requires some of information about the user that be stored to check the user’s identity [2]. it looks like secured, but how the security of smartphones is managed? is the user’s information as safe as it looks? today, malware and data leakage are the most worrying harms of smartphone users. because of these kinds of problems, the users’ laxity appears and puts security organizations at risk.[3] the centralized application delivery architecture is a good and available way for attackers to attack the security and privacy of smartphones. the security sometimes is weak because application checking mechanisms are often not in place and users may choose which protected resources are accessible by third-party applications created by developers [4][5]. most webpages like social networks (facebook, instagram, etc.) store user’s id and password to verify the right user. 1.1. security objectives to keep a system secured, the types of vulnerabilities, that may damage the security of a system, need to be considered. they may be considered by security objectives: confidentiality, integrity, and availability. confidentiality determines who may access or not to what. integrity orders who are allowed to manage or use certain resources. availability describes the request from a legitimate owner to use some resource [1][6]. many companies use antivirus software to prevent the appearance of viruses and other threats [7]. 1.2. security mechanisms three mechanisms are realized: • system modification: requires changing the platform’s core source code including the kernel. • system add-on: requires managing of platform’s core configuration file. add-on means to install appropriate applications for smartphones. • add-on applications: mostly applied by the user by installing and updating (add-on) applications. other applicable mechanisms are an anti-virus solution, firewall, secure api, access control, authentication, spam filter, pre-testing, regular update, and remote access control [1][8]. 1.3. keeping smartphone safety user may keep his/her smartphone safe by using the following steps: • guard his/her phone, and set pins and passwords, • take safety in case his/her phone is lost or stolen, • the user should not override his/her smartphone’s security settings, • backing up and securing his/her data, • installing applications from trusted and safe sources, • using of antivirus software, • using software to find or erase his/her phone data if he/she loses a phone, • clearing his/her phone before dispensing with it, • accepting updates and patches [9], • the benefits of smartphones attract hackers to try to hack and take information from users. because of that, smartphone security and privacy always need to be updated to provide better security for users [10]. 2. literature review with the sudden advance in hardware and software capabilities of smartphones, came the seemingly same set of security issues as with desktop computers, especially considering that smartphones have access to the internet where viruses and various other forms of attack can be performed [11][12]. smartphone security problems can, arbitrarily, be classified into several categories: authentication, data protection and privacy, vulnerabilities, and attacks. these will be discussed in separate sections in the following. dss vol. 5, no.2, 2024, pp. 108-114 110 2.1. authentication problem the authentication method is one in which the owner is confirmed using one of several methods. using a password that one inputs when accessing the device, a token password like a set of nodes pressed a specific way or biometrics such as a fingerprint or iris. wei-han in his research proposed a system where the authentication is implicit. the system learns the user’s behavior pattern in the background continuously updating itself without disturbing the user. this method has been shown to be very effective, being able to detect abnormal behavior within 20 seconds of use with 9095% accuracy [13]. zahid et al. [14] proposed a user identification system to monitor mobile phone key users to distinguish authentic customers from quacks dynamically. the authors used a 25-user data set that only gave a fault of a rate of less than 2%. chine-cheng et al. suggested also a non-intrusive authentication method that collects user data in the background using the device's sensors. the method uses stepwise linear regression to select features of each user the data is then classified using the k-nearest neighbor algorithm. the results show an error rate of 6.85%. the authors concluded that this method can be combined with intrusive methods like pin or password to maximize smartphone security [15]. morris in his research worked on combining multiple authentication methods [16]. there could be implemented sims that allow the user access to the network, without which no traffic can pass to the mobile device which would stop most if not all web-based attacks. 2.1.1. data protection and privacy boshmaf et al. [17] in their studies addressed the problem of data protection. in his analysis, he found that indeed users want to protect their data but often find it inconvenient to do so practically using solutions available today. muslokhlove analyzed the problems of data protection against physical threats and what can be done to combat them. he found that there exist several vulnerabilities in detecting malicious data and when the device falls into the wrong hands. he concluded these issues might for the most part be fixed by updating the lock screen and authentication methods [18]. 2.2. vulnerabilities there exist several types of vulnerabilities that have been described in smartphone devices [19]. these vulnerabilities can be exploited by malicious attackers to gain access to or destroy smartphone devices. smartphone vulnerabilities can be split into: system faults, bad application management, insecure networks, and user unawareness. 2.2.1. system fault when designing any device it is very likely that some hardware and software defects will be left unchecked as it can sometimes be very difficult to find them without extensive use, which is why they are often found only when something has already gone wrong. software faults can, generally, be easily fixed when found but hardware ones often cost a lot more to fix. these defects when found by the wrong may obviously be exploited. 2.2.2. bad app managemanet smartphone devices have very flexible apis which allow for application development, however, this also means that they can be infected with malicious code from said applications. when installing third-party applications these apps might demand high privileges that might update or change system files. attackers might exploit the control and privileges that they might gain. 2.2.3. insecure network when using wi-fi, bluetooth, or gps to connect with any network, a hacker might attempt to retrieve data packets from our device if on the same network. these vulnerabilities can be overcome with various encryption/decryption methods. dss vol. 5, no.2, 2024, pp. 108-114 111 2.2.4. lack of user awareness no matter how much security methods become well there will always be a looming threat of users being jinxed into doing something they shouldn’t. although it’s not easy to think up ways to trick someone these days it still can be done. there are many emails we receive that say they do one thing but pressing a link they provide might in fact do something entirely different that might be malicious. many unacquainted with malicious code have been tricked and will continuously be tricked until awareness is raised. 2.3. attacks there are various ways in which a device could be attacked but they can be subdivided into groups according to their implementation and methodology, although most of them are similar if not the same as those used on desktop and laptop devices. • physical attacks: smartphone devices can be stolen in which case this is considered a physical attack and for the most part responsibility for this does not fall on the manufacturer and there is little they can do to prevent it, but there are ways to find lost or stolen devices. • rebooting attack: when stolen a smartphone device may be accessed with a cold boot, if the information and passwords etc. of the previous user are lost the device can be made to act as if it were newly bought, there exist ways to prevent this but exploits still exist. the following attacks can be classified into malware, or software designed to do something malicious to the device: • backdoor attack: this attack is when a hacker tries to establish a connection with the device whilst not being detected. once the attacker gains access to the system he/she may for the most part do anything the regular user might do including extracting data. these attacks happen most often due to an unhandled exploit in the hardware/software with which the authentication process can be bypassed [20]. • virus attacks: these are scripts designed to infect files, what they do exactly may vary but for the most part they simply make replicates of themselves thus bogging the system down to a crawl [21]. there are ways to detect viruses by continuously analyzing computer activity and network communications for abnormal behavior. • worm attacks: worms are software that tries to send copies of itself from one device to another and much like viruses may also have another purpose to execute when it gets to a device [21]. • trojan: this is a program most famously associated with malware, it is on the surface some sort of useful program or has an otherwise uneventful function but hidden in its code are malicious abilities. for the same reason, they remain very hard to detect as other malware’s activity may immediately be spotted as unusual, a trojan may remain dormant for some time thus evading detection. houmansadr et al. [22] suggested that a cloud-based engine should be made that does a detailed detection on a smartphone device, finding and erasing any threat. • spam attack: spam is a very common form of attack that sends a massive amount of requests or emails that have attached some other malware program. in essence, it is a method of transporting viruses or worms and is often used in hand in hand with other attacks [23]. whereas previous malware was somewhat passive, that being a program already made and then spread the following are active attacks where the attacker is presently attempting to gain access: • brute force attack: the attacker tries to gain access to the device by literally finding out the authentication information. the brute force attack can be further split into an informed and uninformed where an informed attack might use various sets of words from a dictionary or personal information about the user, an uninformed attack tries random combinations until it succeeds. naturally, this takes a very long time and lots of processing power. • denial of service attack: this attack attempts to stop the user from using wi-fi by replacing the original connection with one that just occupies the bandwidth but does nothing essentially. it was proposed by dondyk and zou [24] and they have shown that most iphone and android devices dss vol. 5, no.2, 2024, pp. 108-114 112 were susceptible to this attack. a solution that was also proposed by them was to create an extra protocol where in order to authenticate the network the smartphone device sends a key password using cellular connection to the internet after which it tries to recover the same key using the wifi network. the protocol has already been tested on android devices. • sms attack: much like spam attacks sms messages can be used to send links that might contain malware many operators allow sending credit using sms messages which present a vulnerability that might be exploited. • usb connection attack: usb connections can house various malware which might transfer itself onto a smartphone device there are ways already implemented to prevent usb root access and also to detect if the particular usb connection has risks [25]. • camera vulnerabilities: since almost all smartphone devices have cameras, they have opened a new sphere of possible attacks. there are many applications that demand access to the smartphone camera and some of these might execute malicious operations by running the camera or extracting photos. much of the same issues are shared with sound applications that might take access to the device's microphone. • control flow attacks: attacks that attempt to control which code is executed and have become common. a framework was provided to counteract this attack by monitoring contradicting flow control attempts [8][26]. there are other important research regarding this topic, for example papers [30][31][32][33][34][35], with valuable insights. 3. discussions the first question that appears in our work is:” what does smartphone security mean?”. mobile security refers to the effort to secure data on mobile devices such as smartphones and tablets [27]. the next question is:” do we have a need for smartphone security in our devices?”. the answer is very obvious. yes, the security of our mobile devices has priority over all other needs nowadays. nowadays most of our personal information and data (photos, videos, contacts, etc.) are stored on our smartphones, or through our smartphones we can access them. according to the fbi, more than 4,000 ransomware attack occurred on daily base in 2016. that was a 300 percent increase compared to 2015. if we consider technological improvement and expansion of the smartphone market, we can assume that today we have 15,000 to 20,000 attacks daily [28]. also, according to kaspersky lab android is the most frequently os for malware attacks in the mobile world and the second most targeted platform, right after windows [29]. this information is very worrying because now we see how easily we may be finished as the target of a potential attack. if you ask if is there any solution to this problem, yes there is. actually, there are a lot of solutions for improving the security of your phone and your data, as we already mentioned before [1][8]. some journalists conducted research about reasons why hackers make malware. according to kayla matthews, top five reasons are: • eavesdrop on calls • steal money • blackmail people • damage your phone • threaten national security. 4. conclusions we can conclude that mobile security is very important nowadays. we use mobiles on a daily base, hold our information and data, and communicate over them. malware and ransomware may cause problems in usage or even worse, they may cause leaking of information and data. we may finish as victims of blackmail or theft. we need to be aware of the danger that smartphones bring with their advantages. people need to understand dss vol. 5, no.2, 2024, pp. 108-114 113 all potential threats and act at the right time. we need to educate ourselves and others about the mechanism for dealing with viruses, malware, etc. it is not enough just to install antiviruses on smartphones and think that we are safe. it is also important to take care about which sites we visit, which apps we install, and to whom we give our phones. right-time action is best to prevent any unwanted attacks and data leaking. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] w. jeon, j. kim, y. lee, d. won, “a practical analysis of smartphone security,” in lecture notes in computer science (including subseries lecture notes in artificial intelligence and lecture notes in bioinformatics), 2011. 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[35] r. mueller, s. schrittwieser, p. fruehwirt, p. kieseberg, e. weippl, “security and privacy of smartphone messaging applications”, international journal of pervasive computing and communications, vol. 11, no. 2, 2015. microsoft word 75-83_242 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.75-83 https://doi.org/10.37868/dss.v4.id242 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 75 the new role of the japan self-defense forces (jsdf) under proactive contribution to peace strategy habib al-badawi* 1 department of history, lebanese university, lebanon *corresponding author e-mail: habib.badawi@ul.edu.lb received: jul. 17, 2023 revised: aug. 15, 2023 accepted: aug. 17, 2023 online: aug. 21, 2023 abstract as per the japanese ministry of foreign affairs, no nation can maintain security and peace on its own. therefore, tokyo, through the japanese ministry of defense, contributes to the united nations' efforts to maintain and restore international peace and security. article 9 of the pacifist constitution, in force since 1947, binds japan's defense policy. but global dangers, especially the russian invasion of ukraine, the chinese threats to taiwan, and the madness of the north korean dictator, forced japan to develop the proficiency of the selfdefense forces under the title of “proactive contribution to peace.” in this study, we will review the development of this concept through the process of building japanese military capabilities. this will enable us to respond to societal changes from the korean war to the present. as part of japan's efforts to contribute to international peace and security operations have developed its military capabilities. this includes the enactment of the united nations peacekeeping operations (pko) law, the establishment of the national security strategy, and the purchase of advanced weapons and equipment. the nation’s commitment to international peace and security is also evident in its participation in united nations peacekeeping operations and other regional activities. © the author 2023. published by arda. keywords: japanese constitution; pacifism; proactive peace; security studies; the cold war; legal studies introduction chapter ii: renunciation of war, article 9. aspiring sincerely to an international peace based on justice and order, the japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as a means of settling international disputes. in order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. the right of belligerency of the state will not be recognized [1]. regarding the japanese text above, the english translation does not make it obvious whether “war as a way of dss vol. 4, 2023, pp.75-83 76 settling international conflicts” is related to “war as a sovereign prerogative of the nation”. the nihongo text asserts that “war as a means of resolving international conflicts” is unmistakably linked to both “the threat or use of force” and “war as a sovereign prerogative of the nation”. war is often associated with conquering other nations to resolve international conflicts. without differentiating between offensive and defensive actions, paragraph one denounces all wars. therefore, all military operations, including self-defense wars, can be exploited to settle international conflicts, which makes it difficult to differentiate between an invasion and a self-defense war. the introductory paragraph rejects “violence as a means of solving global disputes”. accordingly, paragraph two does not explicitly prohibit the right to use force for self-defense, so the pacifist constitution does not forbid war as defined by the charter of the united nations. 1. a historical overview with the unconditional surrender of the empire of japan at the end of world war ii [2], japan came under foreign occupation for the first time in its long history. one of the outcomes of their defeat was the pacifist constitution, nihon-koku kenpo. this was imposed, not promulgated, under heavy pressure and mandatory directives from the “supreme command of the allied forces (scap)” led by general douglas macarthur. the american occupation caused a peaceful revolution, restoring civil rights, universal suffrage, and a parliamentary government. this resulted in reforming education, encouraging labor unions, and emancipating women. macarthur was initially directed to exercise authority through the japanese government structure, including the emperor himself. however, he became the de facto commander, organizing and structuring an independent japan under american auspices. the japanese authorities, facing the inevitability of defeat and fearing the annihilation of the japanese nation, applied the aikido strategy that forced the nation to study and practice kata. this was a set of prearranged movements that enabled it to deal with an aggressive adversary successfully. this centuries-old art taught practitioners to use the force of an opponent against themselves, a strategy that gives the nation a definite advantage if attacked. its tactical significance is to accommodate the opponent until victory is achieved. 2. establishment of the japan self-defense forces demobilizing and disarming the imperial japanese army dai-nippon teikoku rikugun was one of scap’s conditions. by abolishing japan's armed forces, dismantling its military organization, and eliminating the expression of patriotism from its schools and public life, japan's security depended completely on the united states forces japan's (usfj) zainichi beigun protection. amid the outbreak of the global cold war between the eastern and western blocs, the international community forced dual polarization. at this stage of the occupation, japan's economic rehabilitation took center stage. scap became concerned that a weak japan would boost the influence of the japanese communist party, nihon kysan-t, which was outlawed during the imperial era [3]. as a communist victory in china's civil war became increasingly uncertain, east asia's future appeared uncertain. japan's debilitating effects were addressed through occupation policies ranging from tax reforms to inflation control measures. the fiery battles in the far east were the korean war (1950-1953) and the vietnamese war (1955-1975), which caused japan to become the principal supply depot for american and un forces, led by general macarthur himself. the conflict placed japan firmly within the confines of the u.s. defense perimeter in asia. after these devastating circumstances, japan gradually returned to being a fully sovereign state with local armed forces that should be allied with the united states army and nato. japan's contribution to western war efforts at the military level was limited to the “logistical” role [4]. in 1954, japan strengthened its defense capabilities during the cold war. the proposed self-defense forces law stated that the primary purpose of the newly formed armed brigades was to defend japan against direct or indirect invasion. the bill was passed by the diet, and the security agency was reorganized as the self dss vol. 4, 2023, pp.75-83 77 defense agency beich. the police and coastal guard units were also reorganized as japan self-defense forces (jsdf) jieitai. the defense agency, a part of the office of the prime minister, was required by article 66 of the constitution to be completely subordinate to civilian authority. the director-general had the rank of minister of state. the highest figure in the command structure was the “civilian” prime minister, who was solely responsible for the diet. thus, in a national emergency, the prime minister was authorized to order the jsdf into action, subject to the regime's consent. however, in times of extreme emergencies, approval might be obtained later. 3. the post-cold war era by the end of the twentieth century, the soviet union had collapsed, and the us had become a unipolar force on the globe. aside from japan, china was the most visible opponent of american unilateralism. in 1992, the law concerning cooperation in united nations peacekeeping operations (pko law), which enabled the dispatch of the jsdf overseas, was passed. nevertheless, a major setback occurred in 1994, when socialist prime minister tomiichi murayama announced before the diet a party policy change stating that a minimum level of military capacity for self-defense was constitutional. the public accepted, as it was constitutionalized, a modest jsdf whose main purpose was disaster relief rather than defense. nonetheless, it opposed the jsdf's substantial growth in military and overseas fighting. to head off any public fears and legislative battles that the government would expand the jsdf’s activities, the bill had a built-in expiration date; it would only last for two years, then the diet would have to vote again on whether to continue or not. the government has thus established five principles to guide the jsdf’s participation in peacekeeping operations: 1. during armed conflicts, all operations must be completely impartial and not favor any party. 2. japan should obtain the consent of both the host countries and the parties to armed conflicts prior to participating in un peacekeeping operations. 3. japanese self-defense force (sdf) units may be withdrawn if any of the above principles cease to be met. 4. the use of weapons should be limited to the minimum necessary to protect the lives of personnel. 5. there must be an agreement between the parties to the armed conflict regarding a cease-fire [5]. the invasion of iraq in 2003 marked the most extreme case of japan’s tilt towards the us in the middle east. japan immediately announced its full support for us military action in the iraqi crisis. this was at a time when most other countries were hesitant and critical of a war breaking out [6]. another jsdf legislative expansion was enacted. the special measures law concerning humanitarian relief support activities and security maintenance support activities in iraq enabled japan to send jsdf troops to an occupied country where small-scale fighting continued. japan's timid start was through the participation of the medical brigade in the self-defense forces in iraq reconstruction and being stationed in samawah with up to six hundred personnel [7]. after the gulf war, japan gradually relied less on military means in its security strategy, marking a turning point for japan. in response to the situation of armed attack law of 2003, the government enacted laws and regulations to implement a contingency plan. this was to protect the nation from attack. under that law, the following seven bills regarding military emergencies were submitted by the cabinet and passed by the diet in 2004 [8]: 1. the act to amend the jsdf law. 2. the law concerning dealing with prisoners of war while under armed attack. 3. the law concerning measures taken by japan during united states military actions while japan is under armed attack (law concerning measures relating to us military actions) dss vol. 4, 2023, pp.75-83 78 4. the law concerning measures to protect nationals in situations of armed attack (the national protection law) 5. the law concerning the punishment of grave violations of international humanitarian law. 6. the law concerning the use of designated public facilities, etc., under armed attack. 7. the law on the restriction of maritime transportation of foreign military supplies, etc., in situations of armed attack (maritime transportation restriction law). meanwhile, the japanese “liberal democratic party” emerged, with its pioneering leadership since independence and its historical symbols, represented by prime minister shinzo abe (the grandson of prime minister nobuskei kishi), who proposed a gradual strategic change in strengthening the japanese army during his second term [9]. when mr. abe became prime minister for the second time in december 2012, the hawkish era began in the japanese government. in july of the same year, mr. abe called, as the leader of the parliamentary majority, to reinterpret article 9. accordingly, the possibility of “collective self-defense” to protect world peace was born [10]. as part of the sixty-eighth general assembly of the united nations on thursday, september 26, 2013, prime minister abe declared that “japan will begin to bear the flag of “proactive contribution to peace,” anchored on the undeniable records and solid appraisal of our country, which has endeavored to bring peace and prosperity to the world, emphasizing cooperation with the international community” [11]. consequently, the japanese armed forces found themselves confronting enormous challenges outside their domestic scope in addition to maintaining internal security. japan was, in other words, seeking to become a global peacekeeping power. in 2014, the ministry of defense (bei-sh) adopted the ittaika theory [12], which entailed integration in the use of force with other militaries, which was deemed unconstitutional by government legal specialists and had no clear premise neither in existing law nor in judicial rulings. they based their judgment on the fact that logistical assistance to foreign combatants should be viewed as a matter of principle and a choice in the national interest, not as a constitutionally debatable issue [13]. the following year, japanese prime minister shinzo abe promoted a bill, which was passed on september 19, 2015, allowing the japanese military to participate in anti-terrorism operations, overturning its previous policy of fighting only to defend the homeland [14]. this legislation came into effect on march 29, 2016. despite the japanese constitution's prohibition on the military acting except in self-defense, the enactment allowed japan's military to operate overseas for “collective self-defense” to defend and protect its allies. under these three conditions, the jsdf could mobilize overseas under government security legislation: 1. japan's people have no other appropriate means available to repel the attack and ensure japan's survival. 2. the use of force is restricted to a necessary minimum. 3. when japan is attacked or when a close ally is attacked, resulting in a threat to japan's survival and posing a clear danger to the japanese people. the involvement of the japan self-defense forces (jsdf) in military actions is explicitly articulated in the framework of “japan's legislation for peace and security.” this legislation establishes “three new conditions” under which the “use of force” is permitted. these conditions serve as guiding principles for the jsdf's military activities, emphasizing the necessity of such actions in particular situations. the first condition stipulates that force is justified when no other appropriate means of evading an attack are available. japan's survival and protection are necessary. this condition underscores the jsdf's primary responsibility to safeguard the nation and its citizens from potential threats. moreover, the legislation allows japan to take on an additional role in un peacekeeping operations and participate in other international peace cooperation activities. by doing so, japan demonstrated its commitment to global peace and security. it dss vol. 4, 2023, pp.75-83 79 contributes to the international community's efforts to resolve conflicts and maintain stability in various regions. the jsdf is also permitted to engage in necessary support activities in situations that significantly impact japan's peace and security. this may threaten international peace and security. this provision emphasizes japan's readiness to take proactive measures when its vital interests and international obligations are at stake. however, it is essential to note that the jsdf uses force strictly to the minimum extent necessary. this aspect highlights japan's commitment to employing military means judiciously, proportionally, and as a last resort. it prioritizes diplomatic solutions whenever possible. the legislation explicitly outlines the circumstances under which the jsdf may employ military force. one such scenario is when japan is attacked, or a foreign country is intricately linked to japan. this poses a clear and imminent danger to japan's survival and fundamentally threatens the people's fundamental rights to life, liberty, and happiness. in such cases, the jsdf is authorized to respond appropriately to safeguard its nation and citizens' well-being. “japan's legislation for peace and security” presents a comprehensive and thoughtful approach to the jsdf's involvement in military actions. it acknowledges japan's responsibility to protect its sovereignty and citizens. it recognizes the nation's role in promoting international peace and security through peacekeeping and cooperative efforts. by adhering to the principle of using force only when necessary and in a limited manner, japan underscores its commitment to resolving conflicts through peaceful means whenever feasible. this legislation serves as a solid and eloquent academic framework that strikes a delicate balance between japan's military responsibilities and its commitment to global peace and security [15]. after the cabinet decision on the “legislation for peace and security,” prime minister shinzo abe announced that “our activities will not be limited to dangerous situations that have a vital impact on japan's peace and security.” under the banner of “proactive contribution to peace,” japan is committed to contributing to global peace and stability even more actively.” 4. domestic and internal burdens the japanese government was trying to address pressing weaknesses in japanese defense, with arms procurement and training being the biggest challenges, and the solution for both was to get the budget to support the development of self-defense forces. for many years, japan's defense budget has been constrained by two main considerations: japan's encouragement by washington to buy the most advanced and expensive u.s. weapons systems and the pressure from the japanese people to limit defense spending to less than 1% of its gdp [16]. as a result, although japan had developed its military arsenal, it suffered from severe shortages of personnel and ammunition. japan's ministry of defense was focused on correcting this imbalance and ensuring its ability to continue fighting in the event of war. this would enable it to survive in the event of a protracted conflict. there has been a lot of internal debate in japan over the proposal to increase defense spending from less than 1% of gdp to 2% [17]. however, this debate overestimates the magnitude of the increase required in the short term. japan already spends about 1.3% of its gdp on matters like veterans' pensions, coast guard costs, and intelligence. correcting the disputed imbalance would thus eliminate the need for rapid accumulation and help strengthen japan's military power. the youth shortage was a fundamental problem, as the number of young people in japan had been rapidly declining. this posed a demographic threat to the survival of the japanese nation. temporarily, the japanese leadership was trying a three-pronged approach: 1. creating a military environment and defense systems that empower women the concept of “tough defensive posture” has been adhered to in japanese defense policy and reports for many years. an aggressive defense stance was strategically indefensible: in the event of an external invasion, the enemy must withdraw from occupied territories, including remote islands. dss vol. 4, 2023, pp.75-83 80 2. investing in artificial intelligence in military operations, the most notable example being autonomous drones. 3. raise the wages and salaries of officers and enlistees in the japanese forces. successive governments have rejected this objection for years, citing the us-japan security agreement as the shield and the us as the spear. in the event of an imminent missile attack from mainland asia, japan must be able not only to stand idly by and “wait for death” but also to preemptively hit enemy missile bases. china and north korea (also south korea) had numerous missile bases, some of which were hidden underground, making such a preemptive strike impossible using current military technology. by contrast, retaliatory strikes, which most countries consider a legitimate and essential aspect of self-defense, can be directed against any aspect of the hostile weapon system, not just the missile bases that threaten japan's security. under the slogan of “proactive pacifism”, the japanese leadership lifted the military restrictions imposed by tokyo in earlier years by operating on three levels: 4. reinterpretation of article 9 of the constitution: this reassessment allowed the ministry of defense to conduct military operations under the right of collective self-defense and was no longer limited to the right to defend japanese territory only. instead, it would come into effect in the event of an armed attack against a country with strong ties to japan. this would be done with japanese forces fighting in defense of the ally. 5. revision of arms export laws [18]: on april 1, 2014, the japanese government eased restrictions on arms exports. under the review, arms exports would be allowed if they contributed to japan's security and complied with the principles of “positive peace”. 6. new development cooperation agreement [19]: on february 10, 2015, japan ratified the comprehensive development cooperation charter. this agreement replaced the system that had been in place since 2002. japan may thus provide aid to foreign armies for non-military purposes such as disaster relief. 5. international trade wars and regional tensions today’s world is experiencing a fierce confrontation represented by the us-china trade war, even though chinese investments dominate the us economy and domestic markets. until recently, financial indicators clearly showed a beijing advantage in direct competition with washington. huawei has faced numerous criticisms for various aspects of its operations, especially cybersecurity, intellectual property, and human rights violations. on november 26, 2019, the us department of commerce issued a highly anticipated proposed rule with proposed regulations (“proposed regulations”) to implement executive order 13873, “securing the information and communications technology and services supply by huawei technologies [20]. the pentagon engaged in economic confrontation. this was while the media was america's most effective weapon against china, even though huawei tried to counter-attack [21]. furthermore, the overall media coverage of the pandemic reached the point of “racism” towards the chinese population and did not exclude other asian communities, despite the entire world being faced with the covid-19 pandemic. as for japan being the neighbor of the chinese superpower, an ambitious dragon, in addition to contemporary rivalry and the dispute over border islands between the two countries [22], these marine rocks are rich in natural resources and buried wealth [23]. hence, the opponent to japanese sovereignty over the senkaku islands/diaoyutai qundao is the “chinese people's liberation army”, which has two and a half million soldiers with massive nuclear capabilities. however, despite wise leadership and a massive armed force, president kim jong-un's temperament, and the ways he controls nukes, pose a real and dangerous threat to dss vol. 4, 2023, pp.75-83 81 japan and the world as well as contributing to world peace. he also faces competition on the other side of the korean peninsula. although south korea revolves around the capitalist orbit and enjoys the protection of us military bases, it has publicly declared hostility towards japan. the historical quarrels between south korea and japan over the islands' sovereignty eventually escalated. furthermore, seoul calls for changing the name of the “sea of japan.” the japanese government supports the exclusive use of the name “sea of japan” while a dispute exists over the international name for the body of water that is bordered by japan, korea (north and south), and russia [24]. in recent years, the world has been amid a japan-south korea trade war after tokyo removed korean companies from the “whitelist” for preferential trading in july 2019. this dispute casts a shadow over the economies of the two countries. another dangerous neighbor is the russian federation, the heir to the soviet union. this country occupied the kuril islands in northern japan and has since turned them into a military reserve stronghold following the inhumane expulsion of its japanese residents. 6. the three pillars of japan's security policy despite japan's economic problems and domestic and international opposition, the government has worked to achieve its three goals: a. japan's possession of defense capabilities [25]: the self-defense forces describe themselves as the “only guarantee” to protect national security from any threat. hence the importance of strengthening these forces so that they can intervene quickly in conflict zones, especially with powerful neighbors. japan is wary of provocative missile tests from north korea, and china represents a massive danger, especially with its ambitions to annex taiwan, albeit by force. to counter the chinese threat, japanese land, sea, and air forces must be able to join hands to counter any sudden chinese escalation. hence, the japanese army is trained in a flexible, fast, dynamic, and integrated manner. b. alliance with the united states [26]: the u.s.-japan relationship is a cornerstone of japan's foreign policy, and these relationships are based on strategic interests and shared values. according to security treaties and tacit consensus, the united states is the guarantee of japan's security. in return, japan allows tokyo to maintain military bases on okinawa and the honshu peninsula. the japan defense forces ensure flexible cooperation to ensure the smooth and effective deployment of u.s. forces. this cooperation continues across joint military programs and land, sea, and air exercises. c. international cooperation: in this context, two forms of cooperation initiated by japan can be distinguished: ● bilateral cooperation: there are several bilateral cooperation agreements between japan and several countries, including australia, india, south korea, the philippines, vietnam, and indonesia. ● multilateral cooperation: this is where tokyo's relationship with major regional organizations in asia, such as the association of southeast asian nations (arf) [27] and the east asian summit (eas) [28], comes into an effective alliance. japan has begun to pursue projects aimed at strengthening its integration with asean. this is because japan wants its member states to have a unified attitude toward china. the japanese government has allocated a large amount of money to this end through development projects and infrastructure support in friendly and allied countries. 7. conclusions amidst this gloomy atmosphere of the regional situation and the immediate danger threatening japan, is it logical to call for the necessity of reducing the exaggerated “peacefulness” while history since the beginning of creation testifies to “survival of the fittest” along with the factors of “intelligence and adaptation”? dss vol. 4, 2023, pp.75-83 82 accordingly, this is the origin of the term “proactive pacifism,” which is based on a historical accumulation that built the japanese armed forces professionally on land, sea, and air to become the fourth army in the world, which recently began building and equipping “space defense forces,” in striking resemblance to the american and russian superpowers' ambitions. japan's proactive peaceful strategy was based on the following pillars: 1. building a rational defense force step by step within the necessary scope of self-defense per national circumstances. 2. security agreements with the united states govern the response to external aggression. this is so that the united nations can act effectively in the future to deter this aggression. to be sure, it is the fourth axis that shaped japan's defense policy for much of the period after the end of direct u.s. occupation. 3. stabilize people's lives, strengthen patriotism, and build a foundation for national security. 4. support the united nations, promote international cooperation, and contribute to world peace. studying the promulgation and birth of “proactive pacifism” clearly indicates that the preparation for harvesting the fruits at the national level consists of sowing suitable seeds and taking care of their growth and intensification while waiting for the appropriate moment to rely on them. hence, the serious construction of the japanese army over the decades following the defeat comes from here. with a sober structure and a solid hierarchy, 2012 was the appropriate decisive moment to increase the budget of the japanese self-defense forces and expand their regional and international role to contribute to building world peace self-defense forces and expand their regional and international role to contribute to achieving world peace. therefore, the constitutional amendments were the inevitable outcome of a continuous historical process. this was built for a stage on which japan would assume a pivotal role regionally and internationally. at the same time, the aim was for a peaceful japan to have an iron hand to protect its land, waters, and airspace and to preserve the “right to claim” the disputed or occupied islands. japan's foreign and security policy on the ground has always followed the principle of “proactive contribution to peace.” the current changes did not come suddenly, but japanese security policy has gradually changed since the end of the cold war, and with slow but steady steps, japan is moving to strengthen its military capabilities to counter any threat that comes from the asian mainland. finally, the reformulated defensive strategy does not enforce the “reinterpretation” of article 9 for the sake of a “proactive contribution to peace”. its explicit defensive strategy strengthens its defense capabilities, improves its defense infrastructure, and increases the presence of its self-defense forces overseas to provide a more comprehensive and effective defense. the goal of the revised defense strategy is to ensure that japan can better defend itself, not to reinterpret article 9 or make a “proactive contribution to peace”. will japan's reformulated defensive strategy enforce the “reinterpretation” of article 9 for the sake of a “proactive contribution to peace”? declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] n. diet, “the constitution of japan”, prime minister of japan, 1947. [2] r. peattie, “the japanese colonial empire”, 1895-1945. nj: princeton university press, 1987. dss vol. 4, 2023, pp.75-83 83 [3] f. jacob, “the continuities and discontinuities of anti-communist state violence in modern japan. in c. s. gerlach (ed.), the palgrave handbook of anti-communist persecutions”, london: palgrave macmillan, 2020. [4] r. dingman, “the dagger and the gift: the impact of the korean war on japan”, the journal of american-east asian relations, pp. 29-55, 1993. [5] mod, “history of japanese pko”, japan ministry of defence, 2019. [6] y. miyagi, “japan’s middle east security policy: rethinking roles and norm”, ortadoğu etütleri, p. 23, 2011. [7] mod, “grassroots human security grant aid to samawah, iraq”, ministry of defence, 2005. [8] n. yoshida, “diet enacts legislation for war contingencies”, the japan times, 2003. [9] t. burrett, “abe road: comparing japanese prime minister shinzo abe’s leadership of his first and second governments”, parliamentary affairs, pp. 400-429, 2017. [10] m. kurosaki, “japan’s evolving position on the use of force in collective self-defense”, the lawfare institute, 2018. [11] t. cabinet, “address by prime minister shinzo abe, at the sixty-eighth session of the general assembly of the united nations”, prime minister’s office, 2013. [12] mofa, “cabinet decision on development of seamless security legislation to ensure japan's survival and protect its people”, ministry of foreign affairs of japan, 2014. [13] n. diet, “report of the advisory panel on reconstruction of the legal basis for security,” the liberal party of japan, 2014. [14] i. takahashi, “japan passes bills to allow troops to fight in overseas wars”, bloomberg, 2015. [15] t. cabinet, “press conference by prime minister shinzo abe following the cabinet decision on the “legislation for peace and security”, cabinet public affairs office, 2015. [16] j. wright,” japan’s self-imposed one percent, does it really matter? journal of indo-pacific affairs (jipa)”, journal of indo-pacific affairs (jipa), 2022. [17] p. o'hanlon, “japan should spend 2 percent of gdp on defense”, csis japan chair, 2019. [18] a. malow, “japan’s new arms export policies: strategic aspirations and domestic constraints”, australian journal of international affairs, pp. 649-669, 2020. [19] mofa, “official development assistance (oda)”, ministry of foreign affairs of japan, 2015. [20] white-house, “executive order 13873: securing the information and communications technology and services supply chain”, presidential documents: securing the information and communications technology and services supply chain, 2019. [21] j. bhojwani, “huawei broadens its campaign to win over american public and media”, npr, 2019. [22] p. smith, “the senkaku/diaoyu island controversy: a crisis postponed”, naval war college review, pp. 27-44, 2013. [23] k. sato, “the senkaku islands dispute: four reasons of the chinese offensive a japanese view”, journal of contemporary east asia studies, pp. 50-82, 2019. [24] mofa, “the issue of the name of the sea of japan”, ministry of foreign affairs of japan, 2017. [25] k. tan, “search of a new security strategy for japan”, east asia forum quarterly, 2022. [26] l. cheng, “the u.s.-japan security alliance”, council on foreign relations, 2019. [27] mofa, “east asia summit”, ministry of foreign affairs of japan, 2022. [28] mofa, “asean regional forum”, ministry of foreign affairs of japan, 2022. microsoft word 65-73_268 (online) issn 2744-1741 defense and security studies original research vol. 5, no. 2, 2024, pp. 65-73 https://doi.org/10.37868/dss.v5.id268 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 65 the changing contours of insecurity in katsina: a threat assessment abdullahi muhammad maigari1* 1al-qalam university katsina, department of sociology, nigeria *corresponding author e-mail: maigariabdullahi@auk.edu.ng received: jul. 9, 2024 revised: aug. 15, 2024 accepted: aug. 16, 2024 online: aug. 20, 2024 abstract threats from armed bandits and kidnappers in northwestern nigeria are in different forms. the landscape of security challenges has changed since 2016, with the intensive war against islamic insurgents in northeastern nigeria called boko haram has changed the contours of security challenges in nigeria. the manifestation of different security threats has been on the increase and the armed bandits have continued to wreak havoc on communities and highways in different parts of nigeria. the security challenge is now a hydra-headed monster, which if one head is cut, another head will develop in nigeria. this article has assessed the current security situation and challenges that beleaguered some states in the northwest geopolitical zone of nigeria with a particular interest in katsina state. the researcher evaluated secondary data on the performance of security personnel deployed to the conflict-affected areas in katsina, state. the assessment covered january to june 2024. however, the data are classified information hence the identity of the personnel and persons who divulged the information cannot be revealed in line with the principles of anonymity in research ethics. the findings found that some of the armed groups in parts of katsina state are kidnapping people to remove some vital organs from their bodies and sell them to those who traffic human organs. based on the assessment, the affected local government areas in katsina state are categorized into four (4) based on the severity and magnitude of kidnapping, cattle rustling and ransacking of villages. drawing from the findings, the researcher has developed policies and strategies to address the changing contours of security challenges in the affected areas and nigeria. as a tradition in threat assessment, the researcher has provided policy recommendations to achieve or implement the policies and strategies. the activities of the armed bandits and organ traffickers portend a grave danger now and in the future as many people would be involved in the business of human organs due to their lucrative nature. the government should develop strategies that will enable the rural communities not to be vulnerable to attacks from armed bandits. armed groups who kill and kidnap residents at will for ransom and organ trafficking if not tamed will recruit new foot soldiers hence aggravating the situation. addressing security threats can be achieved by deploying enough security personnel at the border between the niger republic and nigeria. security personnel should deploy electronic scanners and long-range cameras to monitor and arrest the influx of foreign and domestic dealers in human organs and weapons for appropriate punishment. © the author 2024. published by arda. keywords: armed banditry, kidnapping, security, threats, organ trafficking 1. introduction threats from armed bandits and kidnappers in northwestern nigeria are in different forms. the landscape of security challenges has changed since 2016, with the intensive war against islamic insurgents in northeastern nigeria called boko haram has changed the contours of security challenges in nigeria. the manifestation of dss vol. 5, no. 2, 2024, pp. 65-73 66 different security threats has been on the increase and the armed bandits have continued to wreak havoc on communities and highways in different parts of nigeria. the security challenge is now a hydra-headed monster, which if one head is cut, another head will develop in nigeria. the threats posed by the marauding armed groups in northwestern nigeria are taking different shapes and colours. the landscape of insecurity is expanding, as some terrorist groups are aligning with the armed bandits in the northwest and parts of niger state. the alliance between the armed bandits and international terrorist organizations operating in the corridors of west africa is a major security threat to the corporate existence of nigeria. amani africa report no. 13 [1] has succinctly summarized how all parts of africa, have been affected by different forms of security threats. there is currently no longer a part of the continent where terrorist organizations are not active. as more and more regions run the potential of becoming the scene of terrorist operations, this global expansion keeps going. the threats from terrorist groups and organizations pose a great problem to humanity as terrorists and armed criminals resort to the use of sophisticated weapons against unarmed civilians. international centre for counter-terrorism reported that there is a connection between the offenders' ideologies and the tools they employ in their attacks. while not all of these trends are as obvious, the majority of jihadists use physical weapons (most often knives), the majority of right-wing extremist terrorists use firearms, and the majority of left-wing extremist terrorists commit arson or use fire bombs [7]. the annual threat assessment of the u.s. intelligence community [4] assessed the security threats in west africa which nigeria is included. the report stated that the stability of west africa will be threatened by an explosive concoction of terrorism, inter-communal violence, and democratic regress. recent illegitimate transfers of power in burkina faso, chad, guinea, and mali show the region's brittleness and, in some cases, the public's perception that their government is unable to manage rising insecurity or successfully provide services. some of the still-powerful authorities are adopting autocratic, state-centric, and religious forms of government, concentrating security in important urban areas while handing over rural areas to jihadists [4]. in this assessment of security threats in katsina state and its neighboring states in the northwest geopolitical zone of nigeria, the researcher evaluated the current situation in local government areas that are under constant attacks. incidence of kidnapping, cattle rustling, and ransacking of villages by armed bandits. this threat assessment attempts to explain why some areas than others, are more vulnerable to attacks by the armed groups operating in the affected areas and the consequences of such attacks, killings, and population displacement. additionally, this article also explored an emerging type of crime by the armed groups operating in northwestern nigeria to source money to buy weapons and food. this type of crime is unknown to many researchers and organizations interested in security studies and policy as well as border studies. the sales of captives by armed groups to human traffickers at the international frontiers between nigeria and the niger republic as well as the benin republic is attracting the attention of security experts and social researchers in nigeria and other parts of africa. this is because reputable research organizations like the financial action task force (fatf) in their report on money laundering and terrorist financing risks arising from migrant smuggling [2] did not include the sales of kidnapped victims to those who are into the illegal transactions in organ harvesting. the fatf report [2] revealed that there have been instances of migrant smugglers using their opportunities to commit other crimes, some of which are directly related to but not necessarily implied by migrant smugglings, such as forgery, the corruption of border agencies and other public institutions to aid in travel, and even the administration of addictive drugs to control and exploit their victims. these additional crimes include the trafficking of illegal drugs, theft, harassment, sexual assault, blackmail, human trafficking, robbery, murder, and the exploitation of labour. because this crime is transnational, migrant traffickers can also smuggle products, drugs, and weapons. however, scheper-hughes [6] documented how a terrorist group in syria had engaged in the illicit business of selling the organs of human beings they captured during the war and along the us and mexican border by drug cartels. when police and government officials raided the institute of forensic medicine in yemen in 2012, they found 8,200 body parts that had been stored there. the government acknowledged that the practice of harvesting body parts without permission had become the norm that it was illegal and unethical, that it dss vol. 5, no. 2, 2024, pp. 65-73 67 needed to be acknowledged, that families needed to be compensated, and that the bones, tissues, organs, and other body parts needed to be identified and returned to the families of the victims. to carry out this assessment, the researchers assessed secondary data from security operatives and residents of the villages affected by the insecurity in katsina and the neighboring zamfara states. assessing the security threats and situation of katsina state alone would be insufficient without including some parts of zamfara state because of their proximity and similarity of their population composition. military personnel, the nigeria police force, the nigeria immigration service, the national agency for the prohibition of trafficking persons (naptip), and residents of the affected communities provided valuable information for this assessment. 2. current security challenge in katsina state local government areas of the state are categorized based on their level of security threats or challenges (fig. 1). the magnitude of the security challenge in katsina varies from one local government area to another. based on the classification below, all the local government areas located that are along the kamuku forest which runs from birnin-gwarin kaduna state to jibiya lga in katsina are classified as areas with a severe and high threat of attacks of armed bandits or kidnappers. in this document, those lgas are referred to as corridors of violence because the forest has become a haven for terrorists and armed groups. figure 1. level of security threats 2.1 causes of insecurity there are multiple causal factors of security challenges in different places in the world. some of the causal factors are context-specific or unique to a particular place. in the context of katsina state, some of the causes are as follows. 2.1.1. root causes the causal factors that triggered some people in katsina and other parts of northwestern nigeria to take up arms against the citizens and security agencies are multi-dimensional. however, armed banditry, kidnapping and cattle rustling are not the same as other violent conflicts in northeast (boko haram), farmer-herder conflict in central nigeria and secessionist movement under the independent people of biafra (ipob) and eastern security network (esn) in southeast nigeria. in katsina state, areas that are beleaguered by security severe (severe risk of armed criminal atttacks lgas) bakori, dandume, faskari, sabuwa, kankara high (high risk of armed criminals attacks) batsari, safana, danmusa, jibiya elevated (significant risk of attacks) batagarawa, katsina, dutsin-ma, kurfi, charanchi, kankia, kaita low (low risk of attacks): baure, ingawa, mashi, mani, dutsi, daura, sandamu, maiadua, zango dss vol. 5, no. 2, 2024, pp. 65-73 68 challenges have a history of traditional cattle theft among the nomadic groups who are known for animal husbandry. the cattle rustling has continued unchecked for decades and the nomadic fulani started running out of their livestock which is their major source of livelihood and an indicator of social status in the society. as time went by, the children of the herders grew up without livestock for herding and formal education that would enable them to have formal employment as a means of livelihood either in the villages or in the town apart from herding livestock. in summary, the proximate causes of armed violence and kidnapping are: (a) depletion of livestock in the possession of the nomadic groups. (b) lack of formal education and vocational training in the rural areas to provide alternative livelihood options for the children of the nomads and farmers. over the decades, all tiers of government (local, state, and federal government) in nigeria have not anticipated the impeding danger of neglecting the nomadic population wit live in the forest and bush without livestock and formal education. 2.1.2 proximate causes one of the proximate causes of security challenges (fig. 2) in some parts of katsina state and some neighboring states of kaduna and zamfara is the existence of the forest which harbors criminal elements. from kaduna state to katsina and zamfara, all the local government areas that the forest passes through them, are the worst hit by the activities of the armed criminals, terrorizing the residents and the commuters. in this document, all the lgas in katsina state that rugu forest passes through are classified as "severe risk areas". the criminals find it easy to move from niger state to kaduna via birnin gwari to katsina to zamfara, sokoto and kebbi state without plying the highway. this has made it difficult for security agencies to track their movements, identify their location, and know their identity. another proximate cause of the security challenges is the proliferation of lethal weapons in the west african sub-region since the fall of mu'ammar gadhafi in 2011. niger republic which has a boundary with the federal republic of nigeria is one of the destinations of weapons and fighters from libya, chad and mali. therefore, weapons and fighters from the neighbouring countries of libya have citizens who participated in the war in libya, mali, or chad and have been using the niger republic as a transit route to nigeria. this is because a large segment of the border between nigeria and the niger republic is unmanned and hence exacerbates or transforms the existing security challenge in nigeria. the skills and techniques that armed criminals displayed in northern nigeria from 2009 to 2022 indicate that the majority of them had undergone some illegal forms of weapons training either inside or outside nigeria. in this regard, the smuggling of weapons and ammunition to different criminal groups in nigeria has led to the formation of an illegal cartel which in this document are referred to as conflict merchants or entrepreneurs, that is, those who are into the business of selling weapons and ammunition. some of these merchants import their contraband goods from foreign countries by smuggling them to nigeria and selling them to criminals. some assist the kidnappers with information about people to be kidnapped or assist them in negotiating ransom with the relatives of the kidnapped persons. it has been observed that security challenges have provided an opportunity for the cartel of merchants or entrepreneurs to get money. 3. results the assessment of the threat posed by the security challenges in some parts of katsina is discussed below. 3.1. from kidnappers to human vendors: changing contours of insecurity terrorist organizations worldwide devise different methods to raise funds to finance their activities (fig. 3). from engaging in drug trafficking, money laundering, money courier, illegal mining and engaging in import and export of goods to donations from their sympathizers. however, kidnapping and rustling of livestock in katsina state is taking a different path which is new in the area. kidnappers in some parts of katsina state are dss vol. 5, no. 2, 2024, pp. 65-73 69 no longer demanding ransom from hostages and their relatives again. some of the kidnappers or hostage takers are selling their victims to international syndicates who are in the illegal business of organ harvesting. figure 2. causes of insecurity in katsina state the syndicates are operating between the niger republic and the nigerian border, buying people who are kidnapped in katsina, sokoto, zamfara, kebbi and niger states. this horrific situation is not known to the majority of the security operatives and political leaders in the affected places. this constitutes the most horrendous security threat as it changes the contours of security challenges in the entire nigeria. the security challenge started as a traditional warfare of stealing livestock among the nomadic groups and metamorphosed into a conflict between pastoral groups (farmers) and herders. it has now moved beyond farmers-herders conflict to hostage-taking or kidnapping people for ransom to the senseless killing of people before they kidnap and steal food items and livestock. as most of the communities were running out of livestock, the armed bandits also changed their demands after taking a hostage to put levies on farmers before they were allowed to work in their farms in pre-, during and post-harvest periods. the majority of the farmers in the areas are subsistence farmers whose farm produce when sold, cannot settle the amount levied on them. in realization of the shattered economic life of the people in the affected areas, they had no means to pay the ransom, the terrorists resorted to the selling of human beings to willing buyers. figure 3. methods to raise funds for terrorist organizations root casues proximate casues causses of insecurity proximate causes 1. rugu forest 2. proliferation of weapons 3. existence of conflict entrepreneurs /merchants root casues 1, historic livestock theft 2. depletion of livestock 3. lack of alternative livelihood human vendors rustling of livestock kidnapping ransacking communities levies on residents dss vol. 5, no. 2, 2024, pp. 65-73 70 existing literature and research findings in areas where terrorist groups and other criminals operate in nigeria and other parts of africa have not documented the dramatic shift from kidnapping people for ransom to selling them to criminal cartels who are in the business of organ harvesting in asia and europe. for example, idris [3] stated that nigeria is a supplier and route of human traffickers. nigerians from rural and conflict-affected areas are victims of trafficking, as are those from neighboring nations like benin who are transported to libya (and europe) via nigeria. boko haram has earned a bad reputation for kidnapping women and children for forced marriage, sexual enslavement, and domestic service. examples include the kidnapping of 276 girls from a school in borno state in may 2014 and 110 students from a school in yobe state in 2018. in the work of idris, selling human beings to human traffickers who are into the illegal business of organ harvesting is not mentioned because, at the time he conducted the research, such a problem had not started. this current situation in states in nigeria such as sokoto, katsina, niger, zamfara, and kebbi is fast turning to what happened in some countries like syria, yemen, mexico, iraq, and afghanistan. the terrorists and other non-state actors fuelling insecurity in northwestern nigeria have now realized that community members can no longer meet their huge amount for ransom after they kidnapped their relatives hence exploring a more lucrative avenue for sourcing money to finance their illegal activities as well as feeding and procurement of weapons. organ trafficking in conflict-ravaged areas had started in other countries before kidnapping for ransom and the sale of organs became a new trend of sourcing funds by the criminals operating in the areas assessed in this article. scheper-hughes [6] revealed that boris wolfman (also known as volfman) was detained in istanbul in december 2015. he had been recruiting syrian refugees to sell their organs to foreign transplant tourists who would be treated in one of the many private transplant facilities in turkish hospitals. indicted for organizing illegal kidney transplant procedures in shady clinics in kosovo, azerbaijan, sri lanka, and other locations for foreign transplant patients willing to pay upwards of $100,000 for an illegal transplant with a kidney from an unnamed trafficked person, wolfman was a wanted man in israel. wolfman was regarded as cruel by both transplant tourists and kidney buyers. he belonged to a global network of organized crime that operated on a global scale. early on, it was quite simple to find new immigrants to israel who were eager to live there but in need of assistance. these immigrants were mainly refugees from nations like moldova, ukraine, and romania that had experienced economic collapse. brokers visited new arrivals and assisted them in obtaining residency and even citizenship in israel in exchange for their willingness to aid the country by selling a kidney in a foreign clinic for several thousand dollars. furthermore, kidney trafficking in syria has always been a problem for the poor and members of ethnic minorities. selling kidneys to the destitute was a last resort before the wars that destroyed the nation; it was an unsightly but common practice. today, kidney smugglers traffic syrian migrants and accept them into prison facilities. raad, a 19-year-old syrian refugee, and his six siblings left aleppo for beirut, lebanon. he was approached by abu hussain, a kidney hunter, there. hussain, like boris wolfman, had kidney runners find recently arrived refugees and offer them money and assistance with immigration authorities in exchange for selling a kidney. what could be more advantageous than trading a kidney for a temporary visa? similar to turkey, lebanon has long been a destination for thousands of transplant tourists, many of whom are from the persian gulf. the kidneys needed by transplant patients were previously supplied by palestinian refugees in jordan and lebanon before syrians started filling this void. syrian refugees are today's new, cheaper, and more desperate bait [6]. unlike slavery, servitude, prostitution-related exploitation, or sexual exploitation, "removal of organs" is different from the other prohibited types of exploitation in that it is not an activity that is necessarily exploitative. the 2000 council of europe convention on human rights and biomedicine, along with the 2002 additional protocol thereto on the transplantation of organs, prohibits profiting from the sale of the human body and its parts as well as "organ and tissue trafficking." this prohibition is in addition to the palermo protocol [5]. dss vol. 5, no. 2, 2024, pp. 65-73 71 based above discourse, engaging in trade in human organs by the terrorist groups in nigeria indicates the existence of another means of getting funds to run their activities. this is corroborated by the -terrorist organizations may gain from human trafficking in a variety of ways, including the ability to continue their terrorist actions through human resources, tactical agility, and ideological reinforcement. men, women, and children are trafficked to work for terrorist organizations in a variety of capacities. in addition, women and girls are trafficked to serve as combatants' sexual payoffs [5]. 4. way/means to address the current challenges this threat assessment covered january to june 2024. it takes a team effort and contributions from numerous national and international organizations, including law enforcement agencies, the military, the intelligence services, the financial sector, the diplomatic service, and health organizations to effectively combat terrorism. organization, cooperation, and coordination are essential to success. therefore, kidnapping and other forms of armed violence in northern nigeria are not an exception. table 1. presents policy and strategy to address security challenges. table 1. policy and strategy to address security challenges policy strategy short-term (1 year) medium-term (2 years) long-term (4 years) education (formal & informal) establishment of schools for nomadic and farmer’s children establishment of primary schools construction of houses for head teacher & teachers in the respective villages establishment of junior & senior secondary schools. deployment of security operatives a holistic approach in the fight against the armed bandits. combined operations across states facing security challenges in the northwest & niger state prosecute the arrested criminals to serve as a deterrence to other criminals. for those who surrendered their weapons willingly, the government liaises with the national directorate of employment for vocational training. establishment of police outpost and nscdc office in villages to ensure the presence of security in remote areas. digitalize all interstate roads in katsina state digital roads digital roads with a camerapowered solar system will enable security agencies to track & monitor vehicular movements in the entire state simultaneously. availability of modern electronic gadgets for security surveillance and monitoring. the government should have a mass surveillance document for the state. this enables any time when new security personnel is deployed to katsina state will have a working security document. non-kinetic approach dialogue with the criminals identify authentic leaders of the armed groups and their locations. involvement of miyetti allah kautel hore, miyetti allah cattle breeders & jni as the mediators between government & armed groups. resettlement of the displaced persons. identify the victims & quantify the damage for compensation. eradication of illiteracy among the nomadic groups was one of the rationales behind the establishment of the national commission for nomadic education (ncne) in nigeria. however, for more than three decades, dss vol. 5, no. 2, 2024, pp. 65-73 72 from 1989-2022, there has been no presence of the commission's activity or projects in the rural areas of katsina state where armed banditry has become the order of the day. the government needs to liaise with the ncne in collaboration with the state universal basic education (subeb) to ensure that the children of the nomadic groups are not out of school. this will enable the children to acquire skills and knowledge to survive in the ever-changing 21st century. 5. conclusions the security situation in the areas assessed showed that part of the survival imperatives by the armed bandits and kidnappers is the use of hybrid methods of raising funds for their activities. they collected ransom for hostage-taking and also, sold the victims to internationally organized syndicates of organ traffickers operating in west africa. the destination of human organs from west africa is mostly asia, particularly india and china. the national agency for the prohibition of trafficking in persons (naptip) in nigeria has expressed concern over the number of people who were kidnapped and later disappeared at the hands of the kidnappers. before 2022, different armed groups were operating in northwestern nigeria, stealing livestock that is known as cattle rustlers. the criminals were not eliminated by the authorities concerned and grew hydra-heeds hence the cattle rustlers developed or established a connection with existing criminals along the international boundaries between nigeria, niger republic, republic of benin, chad and cameroon. similarly, the existence of islamic fundamentalist groups in nigeria known as boko haram which later established a working alliance with isis has made it easier for the criminal groups to access weapons. the fall of mu’ammar gadhafi as the leader of libya led to the spread of weapons and fighters who fought in support of the former libyan leader. previous studies have shown that there are different cartels of international criminals who are in the business of migrant smuggling. the main purpose of migrant smuggling is to provide an illicit service, which the migrants pay for and thereby authorize. however, human trafficking makes use of compulsion, trickery, and other tactics to compel someone to be exploited against their will. the involvement of the armed bandits in the acts of organ trafficking and exchange of captives for weapons has added another dimension to the existing fragile situation. human beings are not killed to remove their organs instead of ransom collection. the threats posed by the armed bandits in their connection with islamic jihadists and organ trafficking cartels portends a grave danger not in the northwest alone but in other parts of nigeria. the states which are located at the border between the niger republic and nigeria are the most vulnerable and easy prey to these criminals because the niger republic serves as an easy exit posit and route to enter libya on the road to europe or asia, where they sell such human organs for transplant. this assessment has opened a fresh perspective in dealing with the security threats in katsina state and other affected states in northwestern nigeria. with this problem on the ground, the government and security operatives will have to deal with a complex situation where armed bandits kill people sporadically, for ransom and organ trafficking. policy recommendations are the following: 1) protect the communities: the government should develop strategies that will enable the rural communities not to be vulnerable to attacks from armed bandits and terrorist groups who kill and kidnap residents at will for ransom and organ trafficking. this can be achieved by deploying enough security personnel at the border between the niger republic and nigeria. the security personnel will check and arrest the influx of foreign and domestic dealers in human organs for appropriate punishment. 2) policy of communication: the target beneficiaries of the government policy regarding security strategy should be well-communicated through community engagement with the affected persons and their stakeholders. this will enable the target persons to accept or embrace the policy initiated. the government should utilize the potential of islamic preachers, traditional rulers and community leaders of both farmers and herders to deliver the gospel of peace and its benefits. dss vol. 5, no. 2, 2024, pp. 65-73 73 3) funding of security: funds meant for security should be judiciously used to ensure that security agencies are properly remunerated. both federal and state governments should support security agencies with modern operational gadgets, facilities, and equipment to enable them to protect the lives and property of the citizens. 4) performance evaluation unit: tracking of results in line with the policy and strategies designed. this unit would serve as a watchdog that will monitor and assess the performance of people charged with the responsibility of protecting the citizens doing their work. through termly performance reviews, government or security agencies can detect or identify any personnel who deserve commendation and otherwise. this unit will become a very important component in the implementation of the security policy and strategy of the government. hence it will also enable the government not to deviate from its setup goals. declaration of competing interest the author declares that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] a. africa, "the growing threats of terrorism in africa: a product of misdiagnosis and faulty policy response?", special research report no. 13, 2022. [2] fatf, "ml/tf risks arising from migrant smuggling," fatf, paris, france, 2022. [online]. available: https://www.fatf-gafi.org/publications/methodsandtrends/documents/migrant-smuggling.html. [accessed: 02-aug-2024]. [3] i. idris, "responses to conflict, irregular migration, human trafficking, and illicit flows along transnational pathways in west africa", xcept evidence synthesis, gsdrc, university of birmingham, birmingham, uk, 2022. [4] office of the director of national intelligence, "annual threat assessment of the u.s. intelligence community", jan. 2022. [5] osce office, "where and how they intersect: analysis and recommendations for more effective policy responses", the special representative and coordinator for combating trafficking in human beings trafficking in human beings and terrorism, 2021. [6] n. scheper-hughes, "organ trafficking during times of war and political conflict", human trafficking search, 2016. [7] t. van dongen, w. wentworth, and h. r. arkhis, "terrorist threat assessment 2019-2021", international centre for counter-terrorism (icct), 2022. microsoft word 36-45_235 issn 2744-1741 defense and security studies original research vol. 4, 2023, pp.36-45 https://doi.org/10.37868/dss.v4.id235 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 36 defensive walls: a neglected security strategy in northern nigeria abdullahi, muhammad maigari 1* 1 al-qalam university katsina, college of social and management sciences, department of sociology, nigeria *corresponding author e-mail: maigariabdullahi@auk.edu.ng received: feb. 3, 2023 revised: feb. 22, 2023 accepted: feb. 24, 2023 online: feb. 28, 2023 abstract nigeria from 2016 to 2023 has been facing new security challenges, including kidnapping of people for ransom, sporadic shooting of inhabitants, and the rustling of livestock. there is a rich history of how cities in nigeria, erected defensive walls or fortifications to protect the inhabitants and their property against invaders, criminals, or rustlers centuries before the arrival of the european colonialists to africa. the incessant attacks on rural communities, highways, and urban centers have compelled criminologists and security experts to rethink and revisit the security strategies adopted in the past and worked effectively in protecting the populace and their belongings. kingdoms and empires, as well as emirates in different parts of africa, had developed or erected defensive walls or fortifications which if replicated in the 21st century, will ease neighborhood watch and community surveillance and policing. this paper has helped to identify cities in nigeria with defensive walls and restricted entrances (gates) in places such as kano, katsina sokoto, zaria, and benin city. these are some of the cities known for prehistoric warfare and their people were brave and famous in intercity and inter-community battles. the study found that towns and cities in nigeria and other parts of the world used defensive walls or fortified their jurisdiction against enemies or invaders. the strategy proved effective in protecting their people and property. building defensive walls or fortifications of towns and cities that are facing acute security challenges in nigeria can enable the government and community members to protect the residents. the use of defensive walls will make the use of different mass surveillance tactics much easier because the areas are cordoned off hence patrol, searching, and arrest of criminals. therefore, the researcher recommended that instead of spending huge amounts on the procurement of weapons by the federal government of nigeria, the government should erect or build fences that make criminal investigation more effective hence combat crime and criminals. © the author 2023. published by arda. keywords: armed banditry, kidnapping, fortification, defensive walls, security strategy, mass surveillance 1. introduction fortification walls, also known as defensive walls or battlements, are structures built to provide security and protection. they are typically constructed around a settlement or fortress to defend against external threats such as enemy attacks or invasions. they vary in size, design, and materials used, depending on their purpose and the resources available in the society concerned. they may be made of stone, brick, earth, or a combination of materials, and may include features such as towers, gates, and trenches. throughout history in different parts of the world, fortification walls have played an important role in the defense and security of cities, towns, and other settlements. they have been used to protect against various threats, including military dss vol. 4, 2023, pp.36-45 37 attacks, raids, and sieges. in modern times, fortification walls are still used in some parts of the world for security purposes, although they are often supplemented with other forms of defense such as soldiers, guards, and electronic surveillance. apart from security purposes, fortification walls can also be used for symbolic purposes, such as to mark the boundaries of a city or to serve as a symbol of power and prestige. however, they can also be a source of conflict and division, as they may be used to segregate or isolate certain groups or communities. at the turn of the 21st century, countries in the world are facing both internal and external security threats which demand different measures to protect their citizens and territorial integrity. despite advancements in science and technology as well as the manufacturing of sophisticated weapons by developed and developing countries, and huge spending on the military, some countries continue to build fortification walls for defense purposes. in 1945, after world war ii, there were only seven [7] nations-state in the world that built walls along their international boundaries. however, increasing demand for protection has increased the number of countries with fortified frontiers to 75 in the world. some of the popular historical walls in the world are the great wall of china, the great wall of zimbabwe and the taj mahal in india. among the fortified fences in the world, the benin wall in nigeria was adjudged as the longest, in the world with an estimated 16,000 kilometers. the wall encompassed 6,500 square kilometers of the vast land of the kingdom. the purpose of the walls of benin is to protect the kingdom against marauding invaders which was the reason why the walls were used as a demarcation of the entire kingdom's boundaries hence regulating the in and out of the people in the benin kingdom [11]. this paper aims to examine how defence walls were used in different parts of the world to provide security for the residents. similarly, another objective of the paper is to explain how communities in nigeria had abandoned the building of defense walls making them vulnerable to attacks from rampaging armed bandits, kidnappers and cattle rustlers. 2. context of the problem nigeria is facing a multitude of security challenges, ranging from ethnic violence, religious conflict and religious fundamentalism which has transformed into an insurgency in the northeast part of nigeria. political and ethnic violence has been replaced by another form of crime which is now prevalent in northern nigeria as of 2022. armed groups hiding in forest reserves and mountainous areas in turn, attack communities and kidnap commuters and residents for ransom. the activities of the islamic fundamentalist in the northeast and kidnappers in different parts of nigeria have forced the federal government of nigeria to deploy armed security personnel to virtually 34 out of the 36 states in the country. with the stoppage of the building of defense walls in nigeria, communities, cities and towns have become defenseless, and easily accessible to all forms of criminals. it is within this context, the paper attempt to sample some defense walls in the world to see how they were used as very effective means for protecting the residents and their property. 3. literature review 3.1. defense walls and protection of residents a researcher has assessed the impact of the defense wall called the fortification wall of the kolonna viii in sri lanka. the findings revealed that the fortification was part of the security measures to protect the city against external attacks or aggression. the walls were made of stones, irons, and bricks made from mud and timbers [4] like defensive walls built in some cities in northern nigeria. in russian federation, the castle (narin-kala), and fortress cities which are 40 kilometers of defensive fortifications make up derbent fortress as an architectural structure (mountain wall). the fortress walls preventing access to the sea have been preserved and remain as historical buildings. strategically, the fortress is situated in the caspian passage's most congested and exposed area. two parallel fortress walls that ended at the citadel obstructed the passage along the seashore. the citadel is located on the jangar mountain ridge's highest, seaward ridge. established in the fifth century. up to the nineteenth century, it was a defense structure. steep declensions protect the citadel's northern and western edges [12]. the derbent fortress was not only for decoration of the city but served as a protection against invaders or enemies of the government. impliedly, the derbent walls served two purposes, an aesthetic structure for the beautification and protection of the city. dss vol. 4, 2023, pp.36-45 38 in his doctoral dissertation, succinctly examined the evolution of defensive walls in some cities in syria [6]. the study found that the conflict between ebla and mari, the invasion of the akkadian empire upper land’ the khabur and middle euphrates region and armanum and ebla were some of the reasons for the building of defensive walls in syria. ditches, fort and fortresses, gates, buttresses, towers and bastions, ramparts, fortification walls, glacis, revetment, retaining and casemate walls were found in syrian jazirah, euphrates region, northern levant. the work of jabbour showed the necessity to protect the cities as a result of intercity conflict compelled leaders at that time to design and erect defensive walls for the protection of their rule and dynasty as well as citizens. furthermore, a study has revealed that tell el-retaba wall which is located in a high (arabic: "ras") position on the eastern edge of an ancient lake/marsh, had served as a strategic location in antiquity for the defense of the eastern delta from the gisr and serapeum sills while also being able to control north-south movement through the middle of modern-day wadi tumilat [5]. the construction of the tell el-retaba wall revealed the defense system used in the ancient era in egypt. despite the existence of military and sophisticated weapons in the 19th and 20th centuries, the defensive wall tell el-retaba wall was used by the rulers and their soldiers as a defense strategy. a study on fortification in the arabian states found that as a direct result of emerging transnational concerns including terrorism, irregular migration, drug trafficking, and weapons smuggling, the post-cold war era has seen a dramatic growth in the fortification and militarization of territorial borders. there are around 65 border walls in use today; the majority were constructed in the past three years, primarily in the arab world and eastern europe. although the circumstances and purposes for the border fortifications of the arab states vary, their overall design and building methods are similar. similarly, the different content of the world has their peculiar reason for building defensive walls [8]. security objectives, particularly the prevention of the entry of armed organizations, are the main reasons for the fortification of arab borders. the prohibition of irregular immigration remains the major goal in other regions of the world, particularly in north america and eastern europe. the above findings have revealed that the fortification of states has dual reasons depending on the prevailing situation and need of the state [8]. for example, the moroccan-algerian border has been closed since 1994 as a result of an armed attack on a hotel in marrakech, which morocco blamed on algeria's security forces. the moroccan-algerian border is currently being fortified simultaneously on both sides and without coordination between the two close neighbors. the rivalry between morocco and algeria for regional sway and their numerous political divisions, particularly concerning the western sahara issue, hindered the two nations from cooperating and coming to a consensus on a common approach to securing and maintaining their borders. morocco started construction of a barrier in 2014 along 150 kilometers of its northeastern border with algeria. although morocco and algeria started fortifying their shared land borders at the same time, the priorities of their goals varied depending on the unique problems of each nation. the primary goal of algeria's policy to control its borders is to combat the security threat posed by cross-border armed groups, particularly with mali, libya, and tunisia. in contrast, it is only a secondary goal about its border with morocco, where the primary goal is to combat smuggling, particularly of gasoline. before the extensive fortification project that the two nations had pursued over the previous three years, almost everything was being smuggled through the morocco-algeria border [8]. apart from the orthodox building of defense walls, in the 21st century, some countries have started using barbed-wire fences. the algerian government has started constructing a wire barbed fence along its border with tunisia and libya as a result of security issues on this frontier. the 350-kilometer-long, 3-meter-high fence served the same defensive purposes as fortifications in the majority of other arab nations. the main reason algeria tightened control on its borders with libya and tunisia was because of the unrest in libya's security situation. numerous cross-border armed organizations that have conducted operations in neighboring countries continue to see libya be a favorable environment for their activities. regarding the short-term goals, the new algerian security plan aimed to stop armed group infiltration and prohibit the smuggling of weapons into algerian territory. it is important to note that during the past 20 years, algeria has seen several bombings of public and private facilities as well as kidnappings of foreign nationals by armed organizations across the country's extensive border, particularly in the south [8]. furthermore, fortification became necessary in tunisia due to the turbulence in libya's security. the tunisian government started constructing security fortifications on its border with libya in april 2015. it is a double border barrier that was constructed parallel to one another using water ditches and a sand wall. this dss vol. 4, 2023, pp.36-45 39 fortification, which stretches 220 kilometers along the roughly 500-kilometer border between tunisia and libya, was constructed within five kilometers of the boundary. the fortification cost roughly $75 million to construct and was supported financially and technically by several countries. in comparison to the costs of certain other border fences, such as the saudi fences along its borders with yemen and iraq, this expense is comparatively low. due to the escalating security disturbance in libya, tunisia adopted this security policy. the attack on the bardo national museum in tunis in march 2015, which was carried out by terrorists who entered tunisia across its border with libya, prompted the decision to secure the border. the main goal of the border barrier between tunisia and libya is to prevent armed group members from entering tunisia from libya. since then, these defenses have been strengthened and updated by spanish authorities employing cutting-edge technology, such as infrared cameras, video and audio sensors, observation towers, and radar systems. the eu's policy of hardening its external frontiers against irregular migration includes the construction of barriers at ceuta and melilla. over the past 20 years, thousands of sub-saharan african migrants have made these two enclaves, which serve as a de facto border of the eu in north africa, their final destination [8]. in israel, the "old city," which is central to jerusalem, is enclosed by massive walls constructed by sulayman the magnificent in the 16th century. jerusalem began to build suburbs in the 1860s, just like many other cities in the middle east and the west. the northeastern portion of the expanded city and the mount of olives are collectively referred to as "east jerusalem," which is home to a sizable palestinian population. it is separated from the west bank's palestinian villages by the israeli defense wall and from west jerusalem's predominately jewish neighborhood by north-south road 1[9]. similarly, the paper has identified defensive walls in yemen, syria, iran and other parts of the middle east and explained the walls served defense and decorative purposes in the ancient and present eras. the research was conducted on the architecture of defense, and fortified settlements of the levant during the middle bronze age. the study revealed how in those eras, leaders or rulers relied heavily on the construction of fortified as a protection against enemies and beautification of their territories. some of the walls identified by burke in his study were still existing in the arabian peninsula and near the east [2]. a study has found that thermisi castle was constructed on the precipitous ridge overlooking the nearby salt ponds and sea routes of ermionis in eastern peloponnese, greece. the acropolis and an exterior defensive wall make up the fortification, which guards the settlement and has residential ruins outside of the walling system. the main objective for building the thermisi castle has been explained in the work of simou, klotsa, and koutropoulos. the researchers stated that the fortification's location is unquestionably naturally protective and vital to the defense of the saltpans that extend to the south. the salinities were so significant that they were referred to in a 1451 text as "the most notable salinities in all of the levant, from which one can mine an ore, pozo." in sum, it was for a defensive purpose [10]. the building of walls or barriers has a historical origin from the ancient history of man on earth. the earliest civilization erected defensive walls to protect their territories against invaders. the traditions have defied changes that come with scientific and industrial revolutions and still in the 21st century, nation-states still construct frontier walls for both migration and security reasons. statistics have shown that after the attack on some strategic places in the united states of america on 11th september 2001, there were about thirty countries built defense walls for security reasons [11]. similarly, the researcher identified five reasons why countries build defensive walls. these are: protecting the country against smugglers of contraband goods, protecting the country against the importation of illegal weapons and pharmaceutical products, checking the flow of immigrants and unregistered labour force, prevent the influx of terrorists and diseases. empirical evidence has revealed that from 1989 when the wall of berlin was destroyed, there are about forty countries in the world that erected defense walls to protect their citizens against security threats. morocco has built a security fence of 2,700 kilometers which separated it from western sahara and it is one of the longest active defense fences in the wall. it took the moroccan government seven years to complete the construction of the defense wall, that is, from 1980 to 1987 [11]. similarly, the spanish government has erected a perimeter security fence that separated ceuta and malilla from morocco. the 20 kilometers wall was built in the year 2000 to prevent irregular migrants from entering spanish cities situated at the border with morocco. the spanish authorities had installed closed circuit camera in addition to barbed wires, and motion and noise sensors to detect any attempt to penetrate or destroy the fence by migrants and criminals [11]. dss vol. 4, 2023, pp.36-45 40 in east africa, the fear of attacks from a terrorist group, al-shabab has led the kenyan government 2015 to embark on the construction of seven hundred kilometers of defensive fences. the fence aims to protect the two coastal cities of mandera and kiunga which serve as a route for the al-shabab terrorists to enter kenya from somalia [11]. however, apart from security purposes or reasons, some countries built security fences to prevent their countries from disease. that is, it is for the health of the citizens and some for the livestock. this is the reason for the electrified fence put in place by the government of botswana to prevent the influx of livestock disease from zimbabwe. the 480 kilometers and 2.50 meters high fence was erected to prevent animals from zimbabwe to spread foot and mouth disease to botswana. south africa has also erected an electrified fence base at its border with zimbabwe for the safety and migration of wildlife at kruger park. a 137 kilometers wall or fence was built between south africa and mozambique to prevent fighters of the african national congress (anc) who have an operational base in the mozambican territories to enter south africa. the fence also covered some parts of the border between south africa and swaziland, at jeppe reef mbuzine [11]. the spanish city of cadiz is known for its fortified or defensive wall. the city is covered with three defensive walls with an ocean on the fourth side. this made the city of cadiz the most protected city in the history of spain. an empirical study found that in 1578, king fellope ii of spain decided to fortify the city of cadiz as a result of threats of attacks from other empires in europe, africa and the arabian peninsula. in response to the king's decision, the construction of the fortified walls was handled by an italian engineer captain fratín. the city of cadiz remained the only spanish city that was not attacked at the time of the peninsular war with france [1]. another has examined the impact of the spanish defensive wall in manila, in present-day philippines. in 1571, spain approved the construction of defensive walls in their colonies in asia. as a result of king philip ii, manila was fortified for security reasons. historical evidence has shown that spain erected 14 defensive walls in their former colonies for protection and manila, is among them. this indicated the importance and use of a defensive wall to protect a city or the country against invaders [13]. similarly, it was found that defensive fences and walls are from an economic perspective. they stated that for millennia, humans on all continents have been erecting walls. the primary reason for their early construction was to protect city-states against armies of undesired nomadic neighbors. a massive physical barrier also served as a symbol of political authority, riches, and strength, a claim to territory, and a way to determine who belonged within and who was kept out. walls have ranged in size from small barriers between communities to gigantic fortresses between kingdoms throughout history [14]. as ancient towns spread over the world, so did their walls. in 3000 bc, a 9-kilometer wall surrounded the world's greatest metropolis, the sumerian city of uruk in modern iraq, which had a population of 80,000 people. around 2030 bc, the sumerians built a gigantic 160 km defensive barrier across their realm to keep the amorite nomadic tribes out. it was successful for a few years until invaders either smashed through the wall or just walked around it to destroy sumerian settlements. around 460 bc, the ancient greeks built a variety of fortifications, including the siege-proof long walls of athens. during a conflict with sparta, the fortifications extended from the city to the harbor, but the city surrendered after its navy was crushed at sea. the roman empire fortified its boundaries with a variety of wall-and-ditch fortifications built of turf and stone known as limes between 83 and 260 ad. limes were employed as customs checkpoints for the passage of goods and people, as well as to keep barbarian tribes out of the roman empire. among the most wellknown limes are scotland's 118 km hadrian's wall and 60 km antonine wall, a 750 km wall in north africa, and germany's 568 km limes germanicus. the roman empire significantly invested in its military, and its military conquests provided a stable supply of slave labor to service the walls for a time. expansion slowed over time, as pressure from neighboring barbarians grew. overspending on the military and walls caused a financial crisis and a slew of negative consequences, including harsh taxation and inflation, widespread tax evasion, and a widening gap between rich and poor, predicting the country's eventual demise. although roman limes provided a good defense against unorganized thieves from britain to the arab world, they did not defend the empire from the better-organized barbarian armies of vandals, alans, and goths. from as early as 2000 bc, almost all cities in northern china had defensive walls. larger cities with increased economic activity had longer walls, whereas frontier cities with a larger risk of attack had stronger walls. the defensive role of the walls may have contributed to a perceived sense of security, attracting more people and businesses to the walled cities, which still have a higher population and job densities today. dss vol. 4, 2023, pp.36-45 41 around the year 1200, the little mayan city of tulum in mexico was enclosed on three sides by a 740-meterlong wall for defense against larger city-states. in 1281, japan constructed the genko borui stonewall against a mongol invasion, which is considered to have contributed to the invaders' downfall. between 1500 and 1800, the russian empire defended its southern frontiers with felled wood barricades with ditches and earth mounds, palisades, watch towers, and forts, gradually shifting the barriers south as the empire expanded. these fortifications were safeguarded against tatars and other nomads who were active participants in the slave trade, capturing and selling thousands of eurasians into slavery to the ottoman empire. they also stopped domestic runaway serfs from fleeing and established additional peasant farming land. furthermore, with the increased need to protect citizens against terrorists in the 21st century, different countries facing threats from terrorists started erecting a defensive wall. this is evident when the isis insurgency began to threaten regional stability in the middle east, fifteen new security walls and fences were built to the map around the region between 2002 and 2010. israel erected security walls between itself and the west bank and egypt. egypt constructed an over-and-underground wall with gaza. saudi arabia constructed an 885-kilometer security wall with iraq, as well as barriers with the uae, oman, qatar, jordan, and yemen. the united arab emirates built barriers along its borders with saudi arabia and oman (migration, smuggling, security). jordan constructed fences with syria and iraq. iran has surrounded iraq, afghanistan, and pakistan (security, smuggling). according to israel defense forces, the israeli-egyptian fence was effective in curbing the influx of illegal migrants from africa [14]. outside the middle east, eight new walls were built: between brunei and malaysia (smuggling and migration), myanmar and bangladesh (security), lithuania and belarus (smuggling), kazakhstan and uzbekistan (smuggling), and kazakhstan and kyrgyzstan (smuggling) (smuggling). russia erected a barbed wire fence along its border with georgia (conflict). in africa, botswana erected a border fence with zimbabwe in response to a rush of refugee migrants accused of stealing employment, committing crimes, and spreading hiv. for security purposes, some european countries decided to fortify their international borders. this was done to prevent irregular migrants from having access to their countries. for example, there were seven migration fences were built in europe in response to the massive migration of middle eastern and north african refugees to the eu between 2011 and 2018. macedonia erected a border fence with greece. on their borders with turkey, greece and bulgaria have erected barbed wire fences. hungary built a 175-kilometer fence along its border with serbia and a 350-kilometer fence along its border with croatia. slovakia built a border fence with croatia, and austria built one with slovenia. the united kingdom funded a 13-foot-high barrier in the french port city of calais to keep refugees and migrants out of the country [14]. additionally, oman/yemen, turkmenistan/afghanistan, and pakistan/afghanistan are among the nine new security fences built in the middle east and north africa. turkey and syria, turkey and iran, israel and jordan, israel and syria, israel and lebanon, tunisia and libya, and algeria and morocco. seven additional fences were built in eastern europe and asia as a result of regional conflicts and land disputes: azerbaijan/armenia, ukraine/russia, estonia, latvia, and lithuania built barriers with the russian territory of kaliningrad, kyrgyzstan/kazakhstan, kyrgyzstan/uzbekistan, and china/north korea [14]. estonia/russia, latvia/belarus, poland/belarus, poland/ukraine, hungary/romania, turkey/iraq, india/bhutan, malaysia/brunei, malaysia/indonesia, russia (crimea)/ukraine, and algeria/libya have all announced future fence construction. smuggling, territorial claims, and animal disease control appear to be the primary motivators. except for those erected by the us between guantanamo and cuba, latin america is devoid of border barriers [14]. 3.2. defensive walls in nigeria: a neglected security strategy from around the year 800, several fortifications were built in nigeria spanning several centuries. benin-city was possibly the world's greatest urban planning project at the time, a web of 16,000 km of walls that encircled an entire kingdom made up of hundreds of interconnected cities and villages. europeans demolished benin's walls in 1897. sungbo eredo, the other great wall in the area, was a 160 km wall and ditch earthworks financed by a wealthy queen about the year 1000, meant for defense, unification, and as a shrine for spirit worship. the benin earthwork, which can reach heights of up to 18 meters, depicts an intricate design comprised of a series of inner and outer interconnected circles, as well as an impressive architectural combination of ramparts and moats. the outer walls were made of earthen embankments, which were supplemented by ditches that dss vol. 4, 2023, pp.36-45 42 served a dual purpose: in addition to being an integral part of the walls, they also served as a quarry, storing material used to expand the walls. the exterior barricade was essentially made of earth excavated from ditches dug to create inner moats. there are notable cities in nigeria apart from the benin kingdom discussed above that were fortified before the coming of european colonialists arrived in nigeria. these cities include kano, zaria, sokoto, katsina, lafia and gombe as well as bauchi. there are also smaller towns in northern nigeria that were fortified such as bichi and tsanyawa in kano state, and keffi in nasarawa state. there were walls erected during the period of islamic revival by usmanu danfodiyo and some, were built by kings and rulers for the protection of their throne and subjects against enemies. at different times, rulers of these cities fortified their areas of jurisdiction with fences constructed with mud mixed with stones. the fortified cities and towns in nigeria were relatively safe for the inhabitants because the existence of the defensive walls ensured that the movement of people in and out of the cities or towns was under the watch of the guards stationed at all city or town gates. this is the reason why to date (2023), in cities such as zaria, sokoto, kano, katsina, bichi, rano, hadejia, bauchi, and lafia, there exist gates of doors named after people or historic events. in most cases, the residential areas around the city gates bear the name of the gates. the building of defensive walls of fortification of cities or towns before colonialism in nigeria, particularly in northern nigeria is a testimony of how traditional rulers in pre-colonial nigeria developed an effective strategy to protect their throne, wealth and people against threats from other rulers and kingdoms. with the arrival of european colonialists to protectorates named in 1914 as nigeria, britain destroyed the existing system of governance in northern, southern and eastern protectorates. the colonial government took the administrative and security aspects from the traditional rulers. this marked the end of the construction or building of defensive walls in different parts of nigeria. communities resorted to formal security operatives for protection instead of the traditional fighters and police under the leadership of the emir or king, depending on the area. when cities and towns were fortified, the guards at the gates have techniques of identifying their members and outsiders with the use of language, physique and unique facial and body marks. apart from the guards checking the commuters, there was well-armed personnel stationed at each gate, battleready to repel any attempt by invading enemies or criminals. 4. research methodology the researcher utilized secondary data from documented materials, both academic and organizational in this research. the idea is to use documented historical works on fortification or defense walls in different parts of the world to have an in-depth understanding of how they were used in the past and how such defense walls can useful in nigeria, particularly in areas that are besieged by terrorists and different arm groups. in this regard, the historical research design is the appropriate design for this research. this is because historical research design describes and explain past events (in this case, historical use of defense walls) to understand the present (to examine the positive impact of defense wall in securing the life and property of the citizens) and anticipate the future effects (to examine how the building of defense walls will assist security personnel in fighting terrorists and criminals). 5. results and discussion the defense history of defensive walls or fortification of cities is replete with positive success. the defensive walls mapped out in this study using social mapping have buttressed the effectiveness of fortification of towns and cities against enemies or criminals. states or local government areas in katsina, zamfara, sokoto, kaduna and niger are vulnerable to attacks because different armed groups and non-state actors living in forests on the outskirts of those areas easily enter and attack the residents at will because of the non-existence of any walls or fence that will compel them to enter the town or city through gates. the findings of this study from the documented evidence revealed that kidnapping and ransacking a fortified city or town is difficult because each gate has guards and standing armies. the resistance that kidnappers or bandits will face at the gate will enable those at the city centre to take emergency measures or send reinforcement of fighters. additionally, the chances of armed criminals entering the city and community to steal livestock and kidnap people and escape will be minimal because the residents and armies will block gates that invaders will follow to go out of the community. the findings of [3] have validated the findings in nigeria where kingdoms and emirates adopted the fortification of their towns and cities as an effective security measure. an effort was made to improve fortresses' defensive qualities during the linid and fimid periods. this came about as a dss vol. 4, 2023, pp.36-45 43 result of various conflicts, particularly those in which the fimids were involved. these conflicts included those with the byzantines, who launched several campaigns to retake former christian lands, with independent rulers who had settled particularly in syria, and with the seljuks, who in the eleventh century conquered iraq, a sizable portion of syria, and palestine. however, the latter's coastal regions were dominated by the fimids, who put a lot of effort into building defenses there. from ascalon in the south to jabla in the north, along with certain inland towns like jerusalem and tiberias, they all had their defenses updated [3]. the use of defensive walls in nigeria before colonialism in the 18th century had served as a veritable security measure that shielded different communities against different forms of criminals within and outside. this correlated with the findings which explained how in cyprus, the city of nicosia was fortified and such fortification gave the city maximum protection against domestic and external enemies [7]. it was concluded that the lower portion of the walls, which were solely buttressed by stone, was constructed of mud-brick. the walls at nicosia were restored by the ottomans, who also covered the upper portion with stones. the famagusta walls were renowned across europe, the middle east, and north africa for having been built over many centuries as the city expanded, underwent political upheaval, and adopted new military equipment. they provide a vital record of military design and adaptation to evolving rulers and technology. 5.1 impact of defensive walls on nigeria’s security it could be deduced from the above findings that the use of defensive walls or fortification of communities that are facing incessant attacks from armed groups in nigeria would provide a modicum of protection. this is because when the communities are fortified, the armed groups would not have access to the residential areas at will, without following restricted gates or routes which have stationed guards and armed security personnel. however, building defensive walls has its disadvantages, ranging from the cost of building, maintenance and sustainability of the policy as a security strategy in nigeria where most of the new government introduces new policy and discard the existing ones. despite the huge cost of installing sound sensors, cameras and electrification of the bricks fence or in the case of barbed wire fence. the fortification of communities will enable the security operatives to carry out mass surveillance and reconnaissance surveillance with efficiency. the use of old methods of stop and search by the nigeria police force (npf) would be effective when the areas are cordoned-off with fences. similarly, another aspect that the benefit of a defensive wall outweighed the cost is in conducting mass surveillance. the security operatives such as undercover cops known in nigeria department of state security services (dsss), npf and the military will track and monitor the movement of people both innocents and suspects within an area surrounded by a fence or wall. this measure was adopted by the israeli government to prevent the infiltration of the jihadists from palestinian territories to israel. the barriers had kept in check the movement of people in and out of the west bank and gaza as well as jerusalem. the barriers have contributed to the success of the israeli defence forces (idf) in preventing and intercepting suicide bombers from entering israeli territories. with the barriers, the israeli government under ariel sharon, ehud barak and benjamin netanyahu used the barriers to achieve both security and political objectives. in this sense, with the return of defensive walls to nigeria, the government will achieve both security and political goals, protecting the citizens against kidnappers, cattle rustlers and armed bandits will increase the legitimacy of the government and the popularity of the leaders who implemented the policy. 6. conclusions fortification of cities or towns from the ancient to the modern era has proved to be an effective security strategy adopted by different countries in the world. nigeria, some countries which erected defensive walls had practiced the fortification of cities and towns before the arrival of the european colonialists in the 18th century. with the change of administration during colonialism from the traditional style of leadership to the colonial style, the british colonial administration in nigeria abandoned the idea of building defensive walls to protect the inhabitants. the current security challenges in nigeria which are manifested in the form of hostage-taking for ransom, and rustling of livestock have exposed how unprotected towns or cities are in nigeria. the population of security operatives in nigeria is insufficient to be present in all villages, towns, or cities and this gives the criminals a free hand to operate and launch successful attacks and kidnappings of people. the extant literature examined in this paper has shown how effective defensive walls are, in protecting the target population. the defensive walls or fortifications often simplify internal security management wherever they are erected. therefore, the revival of and construction of new defensive walls in nigeria will dss vol. 4, 2023, pp.36-45 44 enable the citizens and security personnel to effectively monitor the designated entrance and exit to towns and cities hence achieving the goals of mass surveillance in the time of heightened security challenges in 2023. declaration of competing interest the authors declare that they have no any known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. acknowledgments dr. ibrahim sani kankara, department of history, bayero university kano, nigeria. dr. nuhu alamuna, department of nigerian langauges, kaduna state university, nigeria. references [1] c. r. bellido, p.g. pérez. r. l. pantión, "the future of fortifications in the city of cádiz: opportunities and strategies for an urban regeneration", wit transactions on the built environment, vol. 123, pp. 135147, 2012. [2] a. a. burke, the architecture of defense: fortified settlements of the levant during the middle bronze age, dissertation submitted to the faculty of the division of the humanities, department of near eastern languages and civilizations, the university of chicago, 2004. [3] k. d'hulster, k., j. van steenbergen, u. vermeulen, "egypt and syria in the fatimid, ayyubid and mamluk eras", viii. proceedings of the 19th, 20th, 21st and 22nd international colloquium organized at ghent university in may 2010, 2011, 2012 and 2013., orientalia lovaniensia analecta, 2016. [4] w. gauß, kolonna on aigina: the development of a fortified late middle and early late bronze age settlement, austrian archaeological institute, austrian academy of sciences, 2021. [5] j. hudec, m. černý, e. fulajtár, k. fareed, m. nour el-din, "discoveries on fortifications at tell elretaba", asian & african studies, vol. 27, no 1, 2018. [6] a. jabbour, the evolution of defensive elements in the syrian cities and kingdoms during the bronze age: syrian jazirah, euphrates region, northern levant, between the early and middle bronze age, phd dissertation, department of ancient sciences near eastern archaeology, sapienza university of rome, 2020. [7] z. öngül, "historical development of nicosia fortifications and its texture along with the fortification walls", defensive architecture of the mediterranean xv to xviii centuries, 2016. [8] s. saddiki, "the fortification of the arab states' borders in the sub-regional contexts", paix et sécurité internationales journal of international law and international relations, no 6, 2018. [9] a. m. salama, "doha: between making an instant city and skirmishing globalization", mei-viewpoints of the middle east institute, pp. 42-45, 2008. [10] x. simou, v. klotsa, g. koutropoulos, "observations on the architecture of thermisi fortification in argolid from 15th to 18th century", proceedings of the international conference on modern age fortifications of the mediterranean coast, editorial publicacions universitat d’alacant, 2017. [11] j. a. m. tebas, african frontiers: walls to face threats, document analysis, instituto español de estudios estratégicos, jan. 2016. [12] unesco citadel, ancient city and fortress buildings of derbent, commission of the russian federation for city of derbent administration russian committee of icomos, 2001. dss vol. 4, 2023, pp.36-45 45 [13] j. j. verdejo, j. m. cabeza-lainez, j. a. pulido-arcas, c. rubio-bellido, "spanish fortifications in asia: a case study of intramuros district in manila current situation and future prospects", wit transactions on the built environment, no 143, pp. 387-398, 2014. [14] v. vernon, k. f. zimmermann, walls and fences: a journey through history and economics, in the economic geography of cross-border migration. springer, cham, 2021. microsoft word 10-19_261 (online) issn 2744-1741 defense and security studies review article vol. 5, no. 1, 2024, pp. 10-19 https://doi.org/10.37868/dss.v5.id261 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 10 insider threat mitigation through human intelligence and counterintelligence: a case study in the shipping industry anastasios-nikolaos kanellopoulos 1*, 1 department of business administration, athens university of economics and business, greece *corresponding author e-mail: ankanell@aueb.gr received: jan. 30, 2024. revised: mar. 1, 2024. accepted: mar. 2, 2024. online: mar. 7, 2024. abstract this paper comprehensively examines the multifaceted motivations behind insider threats within organizations, elucidating driving forces such as financial gain, revenge, personal aspirations, ideological beliefs, coercion, and negligence. understanding this spectrum is fundamental for crafting effective counterintelligence strategies. the study delves into behavioral indicators crucial for identifying potential threats, emphasizing the significance of recognizing warning signs like unusual data access, unsanctioned software usage, escalated privilege requests, poor performance, disagreement with policies, and more. furthermore, the role of human intelligence (humint) in counterintelligence (ci) and insider threat detection is explored, highlighting its qualitative contribution to understanding human behavior. plus, through a hypothetical case study in the shipping industry, the paper illustrates the direct application of humint principles in fortifying security against insider threats, considering the unique challenges of this dynamic sector. the case study strategically employs employee interviews, psychological assessments, social network analysis, and trust-building initiatives to proactively identify and mitigate potential threats, in an industry reliant on seamless global supply chain operations. © the author 2024. published by arda. keywords: insider threats, human intelligence, counterintelligence, organizational security risk. 1. introduction in contemporary organizational landscapes, the phenomenon of insider threats poses a formidable challenge to security practitioners and scholars alike. the present study embarks on an inquiry into the nuanced motivations underlying individuals' proclivity towards insider threat behaviors within organizational contexts. with a specific focus on the dynamic domain of the shipping industry, our research endeavors to achieve multifaceted goals aimed at elucidating the intricacies of insider threats and fortifying organizational resilience against such risks. foremost among our objectives is a comprehensive examination of insider threats within organizations, underpinned by an understanding of the unique challenges and operational dynamics prevalent in the shipping sector. this entails a meticulous dissection of the diverse motivations driving insider threats, encompassing a spectrum ranging from pecuniary interests to psychological predispositions, ideological affiliations, and instances of coercion or negligence. by delving into this multifaceted landscape of motivations, the paper dss vol. 5, no. 1, 2024, pp. 10-19 11 aims to provide a nuanced understanding that can inform the development of targeted counterintelligence (ci) strategies capable of addressing the diverse array of human behaviors conducive to insider threats. in addition to illuminating the underlying motivations, our study seeks to identify and elucidate behavioral indicators crucial for the detection and mitigation of potential insider threats. recognizing that individual behaviors, while not invariably indicative of malicious intent, often serve as early warning signs, the paper endeavors to delineate common behavioral patterns indicative of insider threat activities. these may include anomalous data access patterns, unauthorized usage of software or systems, aberrant work practices, or unexplained alterations in behavior or lifestyle. by scrutinizing these behavioral cues, organizations can proactively bolster their defense mechanisms against insider threats and preemptively mitigate associated risks. moreover, the central aim is the acknowledgment of human intelligence (humint) as a cornerstone in ci operations, particularly in the realm of insider threat detection. humint, with its unique capacity to decipher the complexities of human behavior, motivations, and intentions, emerges as an indispensable asset in organizational security efforts. by supplementing technological solutions with qualitative insights gleaned through humint methodologies, organizations can gain a holistic understanding of the human factor in security operations and thereby enhance their resilience against insider threats. lastly, to illustrate the practical application of the paper’s theoretical insights, it presents a hypothetical case study centered on a shipping company operating within the global supply chain milieu. through this illustrative scenario, it demonstrates the strategic integration of humint principles in fortifying the company's security posture against insider threats. techniques such as employee interviews, psychological assessments, social network analysis, and trust-building initiatives are deployed synergistically to proactively identify and mitigate potential insider threats. by contextualizing its theoretical framework within a real-world scenario, it aims to provide tangible exemplars that underscore the practical relevance and applicability of its research findings. in sum, the study endeavors to offer a comprehensive and academically rigorous exploration of insider threats, humint, and ci operations within the context of the shipping industry. by illuminating the intricacies of motivations, delineating behavioral indicators, emphasizing the role of humint, and providing practical insights through a hypothetical case study, it aspires to contribute meaningfully to the scholarly discourse and practical endeavors aimed at safeguarding organizations against the perils of insider threats. 2. research method the research methodology employed in this study is a comprehensive review of information, aiming to provide an in-depth exploration of the extensive literature surrounding insider threats, humint, and ci. recognizing the multifaceted nature of these topics, our approach involves synthesizing a diverse array of source materials, including academic studies, government reports, policy documents, and media sources. this inclusive strategy is essential for cultivating a holistic comprehension of the intricate subject matter, offering a nuanced perspective on the motivations, behavioral indicators, and ci measures related to insider threats. by drawing upon a wide spectrum of scholarly and practical insights, this review aspires to contribute to a deeper understanding of the complex interplay between human factors and organizational security. additionally, the research methodology encompasses a hypothetical case study focused on the shipping industry, delving into its unique challenges and potential applications for insider threat detection. through the examination of real-world scenarios and industry-specific nuances, the case study serves to contextualize theoretical concepts within the practical realm, enhancing the relevance and applicability of the study's findings. dss vol. 5, no. 1, 2024, pp. 10-19 12 2.1 insider threats: motivations and behavioral indicators 2.1.1 insider threats motivations the motivations underlying individuals becoming insider threats are nuanced and shaped by a confluence of personal, situational, and organizational factors. delving into the multifaceted nature of these motivations reveals a spectrum of driving forces, each contributing to the complexity of insider threats. specifically, the common motivations for becoming an insider threat are the following:  financial gain emerges as a predominant motivation, compelling individuals to exploit their access to sensitive information, systems, or resources for personal profit. in pursuit of financial motives, insiders may clandestinely steal or sell valuable data, trade secrets, or intellectual property. the allure of financial gain poses a significant risk, particularly in industries where proprietary information holds substantial market value [6].  revenge or resentment represents another compelling motivation, particularly among disgruntled employees who perceive mistreatment, neglect, or injustice within their organizational milieu. seeking retaliation, these individuals may engage in malicious activities such as sabotaging systems, leaking confidential information, or deliberately disrupting operational processes. the emotional underpinnings of revenge or resentment can manifest as potent catalysts for insider threats, necessitating a comprehensive approach to employee well-being and conflict resolution [11].  personal gain, beyond mere financial considerations, propels some insiders to engage in malicious activities for self-benefit. this may include actions geared toward gaining a competitive advantage, advancing one's career within the organization, or seeking recognition and power. the pursuit of personal gain introduces an additional layer of complexity to insider threats, demanding a nuanced understanding of individual aspirations and ambitions [6].  ideological or political beliefs emerge as motivating factors, driving insiders to promote a cause or advance a particular agenda within their organizational context. this may involve leaking sensitive information, disrupting operations, or engaging in activist endeavors aligned with deeply held convictions [6]. the intertwining of personal ideologies with organizational dynamics underscores the importance of considering ideological motivations in the identification and mitigation of insider threats [11].  coercion or blackmail introduces a dimension of external influence, as insiders may be compelled into becoming threats through threats to their personal safety, reputation, or financial well-being. the vulnerability of individuals facing external pressures underscores the need for robust ci efforts aimed at identifying signs of coercion and intervening before insiders unwittingly become instruments of external manipulation [3].  negligence or carelessness represents a distinct, albeit unintentional, motivation for insider threats. in certain instances, individuals may breach security protocols, mishandle sensitive information, or inadvertently cause damage to systems or data due to negligence or carelessness. recognizing that not all insider threats are driven by malicious intent is crucial for devising strategies that encompass both intentional and unintentional security breaches [25]. eventually, understanding the diverse motivations behind insider threats is imperative for developing comprehensive and effective ci strategies [21]. financial gain, revenge, personal aspirations, ideological beliefs, coercion, and negligence collectively contribute to the intricate landscape of insider threats. organizations must adopt a multifaceted approach that addresses these motivations through a combination of preventive measures, employee support programs, and a robust security infrastructure to mitigate the risks associated with insider threats [25]. dss vol. 5, no. 1, 2024, pp. 10-19 13 2.1.2 insider threats behavioral indicators behavioral indicators serve as crucial elements in identifying potential insider threats within an organization, offering valuable insights into activities that may deviate from established norms. while individual behaviors are not unequivocal evidence of malicious intent, they can serve as warning signs necessitating further investigation [20]. the following elucidates some common behavioral indicators that may suggest insider threat activity:  unusual data access or movement: employees accessing or moving substantial volumes of data beyond the scope of their job responsibilities or normal patterns can raise suspicion [15]. an abrupt departure from established data usage patterns may signify potential unauthorized activities, necessitating a closer examination of the employee's actions [7].  use of unsanctioned software and hardware: the use of unauthorized or unapproved software, applications, or hardware by employees can indicate attempts to circumvent security measures or conceal malicious activities [27]. monitoring for such deviations from sanctioned tools becomes imperative for maintaining the integrity of the organization's security infrastructure [9].  increased requests for escalated privileges: frequent or abrupt requests for elevated access privileges, exceeding what is essential for an employee's role, may point to an effort to gain unauthorized access to sensitive information or systems. organizations should scrutinize such requests to ensure they align with legitimate job responsibilities [27].  poor performance or disgruntlement: a decline in job performance, recurring conflicts with colleagues or supervisors, or expressions of dissatisfaction with the organization can be indicators of potential insider threats. monitoring employee satisfaction and promptly addressing workplace concerns can mitigate the risk associated with disgruntled individuals [20].  voicing disagreement with policies: consistent vocal disagreement with organizational policies, procedures, or security measures may suggest an increased likelihood of engaging in malicious activities. organizations should foster open communication channels to address concerns constructively and minimize the potential for dissent to turn into insider threats [6].  working outside normal hours or accessing systems off-hours: employees consistently working late or accessing systems during non-business hours without a legitimate reason may raise suspicions of unauthorized activities. monitoring access logs and establishing clear protocols for after-hours system usage can aid in identifying potential insider threats [20].  attempts to bypass security measures: deliberate efforts to bypass security controls, such as disabling security software or circumventing access controls, can indicate malicious intent [15]. regular security audits and monitoring of system logs are essential for detecting and mitigating insider threats attempting to compromise security measures [6].  unusual financial transactions: employees involved in suspicious financial activities, such as unauthorized financial transfers, unusual cash flow, or unexplained financial gains, may be engaging in insider threats for financial gain. organizations should closely monitor financial transactions and implement robust controls to detect and prevent such activities [9].  changes in behavior or lifestyle: sudden changes in an employee's behavior, lifestyle, or financial situation, such as excessive gambling, substance abuse, or financial difficulties, can be indicators of potential insider threats. early intervention, through employee assistance programs and counseling, can address underlying issues and mitigate the risk of such behavioral changes leading to security breaches [9]. in short, recognizing and interpreting behavioral indicators is integral to the proactive identification and mitigation of insider threats. organizations must implement comprehensive monitoring mechanisms, coupled with clear protocols for responding to potential indicators, to safeguard against the diverse array of behaviors that may signify malicious intent. dss vol. 5, no. 1, 2024, pp. 10-19 14 2.2 the role of human intelligence in counterintelligence humint is a cornerstone in the field of intelligence gathering, encompassing a multifaceted approach to collecting, analyzing, and interpreting information derived from interpersonal interactions [22]. at its core, humint relies on human sources—spies, informants, and operatives—who engage in direct communication with individuals to extract valuable insights [18]. unlike other forms of intelligence, such as signals or imagery intelligence, humint is uniquely positioned to decipher the complexities of human behavior, motivations, and intentions [3]. in the realm of ci, where the focus is on identifying and mitigating insider threats, humint emerges as a critical component [1], [24]. understanding the human element behind potential security risks is paramount, and humint provides the nuanced context necessary for effective decision-making [12]. through interviews, debriefings, and other interpersonal methods, humint specialists can gather information on individuals' backgrounds, affiliations, and potential vulnerabilities to coercion or manipulation [11], [24]. this depth of understanding enables ci professionals to proactively identify and neutralize insider threats before they materialize [1]. humint's emphasis on the human element complements technological solutions by adding a qualitative layer to the intelligence spectrum, offering insights that algorithms and automated systems may struggle to discern [3]. the value of humint in ci lies not only in its ability to uncover information but also in its capacity to contextualize data within the intricate tapestry of human behavior [1]. by tapping into the rich tapestry of interpersonal connections, motivations, and loyalties, humint contributes to a comprehensive understanding of the human landscape within an organization, enhancing the capacity to identify and mitigate insider threats effectively [22]. as technology continues to evolve, humint remains an indispensable tool in the intelligence toolkit, providing a human touch to the often intricate and subtle dynamics of ci operations [8]. 3. results and discussion 3.1 insider threats identification through humint humint sources constitute a rich tapestry of methods that delve into the intricate realms of human behavior, motivations, and intentions, offering invaluable insights for organizations aiming to identify and counter potential insider threats before they materialize [18]. employee interviews represent a cornerstone in the humint toolkit, offering a direct and personalized approach to gathering critical information. skilled interviewers play a pivotal role in navigating the intricacies of human interaction, employing a combination of empathy, intuition, and expertise to elicit valuable insights [11]. these interviews transcend superficial observations, allowing interviewers to delve deep into the layers of an individual's behavior, motivations, and intentions. by establishing rapport and trust, interviewers create an environment conducive to open communication, encouraging employees to share candid responses that may unveil subtle nuances in their demeanor or provide glimpses into their mindset [16]. the richness of employee interviews lies in their ability to explore beyond the immediate context, uncovering the individual's unique experiences, perspectives, and potential grievances. this holistic approach aids in constructing a comprehensive profile, shedding light on aspects that automated systems or technological solutions might overlook [11]. understanding an employee's mindset is crucial for anticipating their reactions to various stimuli, identifying potential stressors, and assessing their susceptibility to external influences. furthermore, employee interviews contribute to a proactive approach to recognizing any signs of dissatisfaction or potential alignment with insider threat indicators [4]. organizations that embrace employee interviews as a core component of their humint strategy demonstrate a commitment to understanding the human element within their workforce [21]. this method not only serves as an early warning system for potential insider threats but also fosters a culture of transparency, where employees feel heard and valued. in an era where the human factor remains pivotal in organizational security, the nuanced insights gleaned from employee interviews dss vol. 5, no. 1, 2024, pp. 10-19 15 empower decision-makers to make informed choices, thereby enhancing the overall resilience of an organization against emerging threats [2]. besides, psychological assessments, as a potent source within humint, introduce a layer of scientific precision to the evaluation process, offering organizations a sophisticated means of understanding an individual's psychological makeup. employing a range of standardized tests, personality assessments, and behavioral analyses, organizations can delve into the intricacies of an individual's psyche. these assessments are designed to unveil aspects of personality, emotional well-being, and cognitive processes, providing a more profound understanding of an individual's behavioral patterns. by examining responses to specific stimuli and gauging reactions in controlled environments, organizations can identify predispositions, emotional triggers, and potential stressors that might influence an individual's decision-making process [11]. the ability to recognize indicators of stress, discontent, or susceptibility to external pressures is crucial for conducting a comprehensive risk assessment, especially in the context of insider threat detection [4]. psychological assessments contribute to a proactive approach by uncovering potential vulnerabilities or areas of concern that may not be immediately evident through traditional means [7]. insights garnered from these assessments enable organizations to tailor intervention strategies, implement targeted support mechanisms, and foster a healthier work environment [21]. by combining the empirical rigor of psychological assessments with other humint methods, organizations can construct a multidimensional profile of individuals, enhancing their ability to detect, mitigate, and prevent insider threats. this holistic approach, leveraging both the subjective and objective dimensions of human behavior, underscores the significance of psychological assessments in fortifying an organization's security posture against evolving threats in an increasingly complex and interconnected world. additionally, social network analysis stands as a powerful augmentation to the humint toolkit, offering a sophisticated means of unraveling the intricate web of relationships, affiliations, and communication patterns within an organization [1]. this method involves scrutinizing connections between individuals, allowing analysts to discern not only the formal organizational structure but also the informal networks that underpin it [11]. by mapping the interplay of relationships, analysts can identify potential influencers, individuals with an outsized impact on decision-making or group dynamics [5]. moreover, social network analysis enables the identification of isolated or disgruntled employees, those on the fringes of the social fabric whose sentiments may harbor risks to organizational cohesion and security [7]. further, this method allows organizations to gauge the strength of allegiances, unveiling the depth and nature of connections between employees. understanding the social dynamics within an organization becomes pivotal in identifying potential insider threats [17]. patterns such as sudden changes in alliances, unusual collaborations, or the emergence of cliques may signify shifts in employee loyalties that merit closer scrutiny [11]. by visualizing the human landscape through social network analysis, organizations gain the ability to identify potential insider threats early in their gestation, providing a proactive approach to security [1]. the power of social network analysis lies in its capacity to offer a comprehensive, visual representation of the human relationships that shape an organization. this method goes beyond individual assessments and unveils the collective dynamics that influence behavior and decision-making. by integrating social network analysis with other humint methodologies, organizations can develop a holistic understanding of their workforce, enhancing their ability to detect and mitigate potential insider threats before they materialize [11]. in the ever-evolving landscape of organizational security, this multifaceted approach positions social network analysis as a vital tool for identifying and navigating the complexities of insider threats [5]. in due course, combining these humint sources and technique approaches empowers organizations to construct a nuanced profile of individuals, allowing for a more informed assessment of the risk they may pose as potential insider threats. by integrating these diverse methods, organizations can proactively identify anomalies, behavioral deviations, or signs of discontent that might otherwise go unnoticed. this proactive approach positions humint as a key ally in the ongoing battle against insider threats, providing decision dss vol. 5, no. 1, 2024, pp. 10-19 16 makers with the tools to intervene before potential risks escalate [4]. as technological advancements continue to reshape the landscape of security, the human touch afforded by humint remains indispensable, offering a complementary perspective that augments the capabilities of automated systems and algorithms. the synergy of employee interviews, psychological assessments, and social network analysis creates a robust framework for understanding the complex interplay of human factors within organizations [1]. in a rapidly evolving threat landscape, organizations that harness the power of humint sources are better equipped to identify, mitigate, and prevent insider threats, safeguarding their assets, reputation, and overall security posture. 3.2 building trust, relationships, and counterintelligence culture building trust, fostering positive relationships, and cultivating a robust ci culture are imperative components for the effective implementation of humint within an organization or business [1]. at the core of humint lies the fundamental necessity for reliable information gleaned through interpersonal interactions, where trust serves as the linchpin in this intricate process [2]. establishing trust commences with the creation of an organizational culture that places a premium on transparency, fairness, and open communication [14]. this foundational framework is pivotal in instilling confidence among employees, assuring them that their concerns and observations will be handled with the utmost seriousness and without any fear of repercussion [8]. a significant deterrent to the reporting of suspicious behavior is the apprehension of retaliation, underscoring the critical need for organizations to actively cultivate an environment where individuals feel safe to come forward with potentially vital information [14]. leadership plays a central role in this endeavor, with its approachability, empathy, and responsiveness setting the tone for an organizational culture that places a high value on the human element [2], [19]. in addition, leadership commitment to listening, understanding, and addressing employee concerns is integral to creating an atmosphere conducive to trust. by demonstrating empathy and responsiveness, leaders not only foster positive relationships but also lay the groundwork for a culture that prioritizes the well-being and contributions of its workforce [2]. this approach extends beyond mere rhetoric; tangible actions must accompany these principles to fortify the trust-building process. furthermore, implementing anonymous reporting channels and whistleblower protection programs further solidifies the commitment to creating a secure environment for reporting. these initiatives empower employees to share information without fear of reprisal, thus facilitating early detection and intervention in potential security threats. such mechanisms serve as essential safeguards, allowing individuals to contribute valuable insights without compromising their well-being. in essence, trust and positive relationships constitute the bedrock upon which humint thrives. the seamless flow of valuable information, unencumbered by fears of retribution or mistrust, is foundational to the success of humint strategies [21]. as technological advancements continue to reshape the security landscape, the enduring significance of the human factor becomes increasingly evident. the unique ability of individuals to discern, interpret, and contribute information remains irreplaceable, underscoring the indispensable role of trust-building and positive relationships in bolstering the effectiveness of humint within the broader framework of organizational security. moreover, a robust ci culture must permeate the entire organization, fostering a collective commitment to vigilance and security [2]. this culture encompasses not only leadership initiatives but also the active participation of every individual within the organization [8]. security awareness programs, regular training sessions, and clear communication of security policies contribute to instilling a sense of responsibility and ownership regarding ci measures [21]. plus, a resilient ci culture involves continuous assessments of potential vulnerabilities, adapting strategies to evolving threats, and integrating ci into daily operations seamlessly [8]. encouraging employees to stay informed about security best practices, promoting a sense of dss vol. 5, no. 1, 2024, pp. 10-19 17 collective responsibility for organizational security, and fostering a proactive mindset are essential components of this culture [2]. 3.3 case study on shipping industry in a hypothetical case study of a shipping company, the principles of humint are directly applicable in fortifying the company's security posture against potential insider threats. the intricacies of the shipping industry, which depend heavily on the timely and secure movement of goods across borders, underscore the imperative for safeguarding operations, sensitive information, and reputation [13], [23]. the operation of a shipping company implies the need for a comprehensive security strategy that integrates humint methodologies to address the unique challenges inherent in the industry [10], [26]. the initial step involves the implementation of employee interviews as a pivotal humint strategy [21]. trained interviewers engage personnel at various hierarchical levels within the organization, aiming to unveil subtle nuances in behavior that may indicate signs of discontent, stress, or anomalous activities. by conducting targeted interviews with key personnel responsible for logistics, information technology, and security, the shipping company can acquire a nuanced understanding of potential vulnerabilities that may be exploited by insider threats. then, psychological assessments assume a critical role in this context, offering a systematic and empirical approach to evaluating the psychological well-being of employees, particularly those occupying critical roles within the organization. subjecting individuals to standardized tests and behavioral analyses enables the shipping company to gain insights into predispositions, emotional triggers, and potential areas of concern. for instance, employees tasked with handling sensitive cargo or managing vital communication systems may undergo assessments to ensure their psychological resilience against external pressures or coercive influences, thereby fortifying the organization against potential insider threats. furthermore, social network analysis emerges as an indispensable tool for navigating the complex interpersonal relationships within the organization [1]. by mapping connections between employees, the shipping company can identify influencers, detect isolated or disgruntled individuals, and gauge the strength of allegiances within the workforce. this method assumes particular relevance in an industry where collaboration and communication are paramount, and the dynamics of interpersonal relationships can significantly impact operational efficiency. analyzing the social fabric of the company, through a humint lens allows the shipping company to proactively identify potential insider threats based on social dynamics and relationships. over and above the previous, in an industry like shipping, where the potential for insider threats to compromise the security of cargo or sensitive information is a significant concern, initiatives centered around trust-building take center stage [10]. establishing an organizational culture that encourages open communication, values transparency, and actively supports whistleblower protection is paramount [2]. leadership within the shipping company must foster an environment where employees feel safe reporting suspicious behavior without fear of retaliation. the implementation of anonymous reporting channels ensures that employees can share vital information about potential threats without compromising their own safety or job security. 4. conclusions in conclusion, this paper presents a comprehensive exploration of insider threats, humint, and ci, with a focus on motivations, behavioral indicators, and the role of humint in organizational security. the multifaceted motivations behind insider threats, including financial gain, revenge, personal aspirations, ideological beliefs, coercion, and negligence, underscore the complex landscape organizations must navigate. recognizing these motivations is vital for developing effective ci strategies that address diverse arrays of dss vol. 5, no. 1, 2024, pp. 10-19 18 human behavior. behavioral indicators, such as unusual data access and changes in behavior, serve as crucial warning signs for potential threats, necessitating proactive identification measures. in due course, the pivotal role of humint in ci operations is emphasized, highlighting its unique ability to decipher human complexities. humint provides a qualitative layer that complements technological solutions, ensuring a holistic understanding of the human factor in security. finally, the hypothetical case study on a shipping company further illustrates the direct applicability of humint principles, showcasing the strategic integration of employee interviews, psychological assessments, social network analysis, and trust-building initiatives to fortify security against insider threats in the dynamic shipping industry. declaration of competing interest the author declares that has no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] a. n. kanellopoulos, "the dimensions of counterintelligence and their role in national security", journal of european and american intelligence studies, vol. 6, no. 2, 2023. 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[19] m. lowenthal, intelligence: from secrets to policy. washington, dc: cq press, 2009. [20] m. rudner, "protecting critical energy infrastructure through intelligence", international journal of intelligence and counterintelligence, vol. 21, no. 4, pp. 635-60, 2008. [21] m. d. stouder and s. gallagher, "crafting operational counterintelligence strategy: a guide for managers", international journal of intelligence and counterintelligence, vol. 26, no. 3, pp. 583-596, 2013. [22] a. c. magee, "countering nontraditional humint collection threats", international journal of intelligence and counterintelligence, vol. 23, no. 3, pp. 509-20, 2010. [23] n. giannakopoulou, e. i. thalassinos, and t. v. stamatopoulos, "corporate governance in shipping: an overview", maritime policy & management, vol. 43 no. 1, 2016. [24] of moles and molehunters: a review of counterintelligence literature, 1977-92. center for the study of intelligence, 1993. 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[27] the national infrastructure advisory council, the insider threat to critical infrastructures, 2008. microsoft word 1-24_275 (online) issn 2744-1741 defense and security studies original research vol. 6, no. 1, 2025, pp.1-24 https://doi.org/10.37868/dss.v6.id275 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 1 research on design and implementation of innovative ugv modular platform in mine action programs dženan ćosić 1, alan ćatović2, muamer delić3, jasna mujkić4 1 department of product design, academy of fine arts, university of sarajevo, bosnia and herzegovina 2 defense technologies department, mechanical engineering faculty, university of sarajevo, bosnia and herzegovina 3 department of mechanical constructions, mechanical engineering faculty; university of sarajevo, bosnia and herzegovina 4 department of product design, academy of fine arts, university of sarajevo, bosnia and herzegovina *corresponding author e-mail: cosicdzenan49gmail.com received: jan. 02, 2025 revised: jan. 20, 2025 accepted: feb. 1, 2025 online: feb 6, 2025 abstract this research paper focuses on the development of an innovative system applying the ugv (unmanned ground vehicle) modular platform in the fields of humanitarian demining, where the scientific research process demonstrates the multifunctional application of such systems, or similar ones, in civil protection sectors. the use of the ugv platform enables more efficient mission completion in scenarios where human lives are directly at risk, such as demining operations. the ugv platform, with its modular design and development approach, represents a modern method for the advancement of such systems, offering multi-operation and multifunctional applications. © the author 2025. published by arda. keywords: humanitarian demining, ugv (unmanned ground vehicle), civil protection 1. introduction the resolution of the global issue of residual landmines and unexploded ordnance (uxo) has always been one of the most strategically demanding tasks. apart from posing significant risks to safety, it also presents a substantial challenge in terms of accessibility to difficult and demanding terrains. the problem of residual mines and uxo is inherently significant and complex; when coupled with challenging terrain, the issue escalates to an extreme level. systems for mine and uxo clearance have been in existence for many years, especially mechanical systems that have proven to be among the most effective and efficient solutions. these systems not only enhance operational effectiveness but also provide exceptional protection to personnel on the field. research regarding this topic can be found ie. in [1,2,3,4,5,6,12]. a large majority of minefields and uxo are estimated to be located in highly demanding terrains with uneven topography. bosnia and herzegovina, a country heavily affected by the residual mine and uxo problem, exemplifies this issue, particularly due to its challenging topography. this serves as the foundation for the scientific research presented herein, which proposes a potential solution. the demanding topography of bosnia and herzegovina poses a unique challenge to resolving the residual mine and uxo problem. existing solutions available on the market are effective only on slopes not exceeding 15 to 20 degrees, which is significantly below the gradient of the terrain where minefields are located in bosnia and herzegovina. over the past few decades, dss vol. 6, no. 1, 2025, pp.1-24 2 from the 1990s to the present day, several innovative solutions for demining in challenging terrains have been developed. however, none have reached the stage of serial production. difficult and uneven topographical areas are still cleared primarily using manual detection and removal methods, which carry a high risk for field personnel. while manual methods, alongside mechanical approaches, remain among the most effective demining techniques, they come at a considerable cost to human safety. the primary objective of designing and developing solutions that facilitate mine and uxo clearance is to prioritize the protection of human lives. 2. machines that save human lives in our previous paper [6] we elaborated on the issue of landmines both globally and in bosnia and herzegovina, with a particular emphasis on the most effective methods for detecting and removing mines and uxo in terrains with challenging topography. machines that save lives are precisely those systems based on mechanical demining principles, which have demonstrated both effectiveness and efficiency. according to an analysis conducted by the croatian mine action centre (hcr), performed in accordance with the international mine action standards (imas) and national mine action centres (mac), it has been shown that a single demining machine can accelerate the demining process by 50%. this equates to replacing the work of three sniffer dogs (biosensor detection method) or the efforts of two demining teams (16 individuals) [1]. 2.1. economic factor in addition to accelerating the demining process for a given area, mechanical systems directly protect and save human lives by eliminating the need to expose trained personnel to direct danger. moreover, the accelerated process enables a reduction in suspected mine-explosive areas, which significantly impacts the number of potential casualties. this is particularly critical, as a large portion of suspected mine-contaminated areas in bosnia and herzegovina is still located near populated regions. the protection and preservation of human lives, as previously emphasized, remain the most important priority. however, another crucial factor that justifies the use of mechanical demining systems, especially in terrains with demanding topography, is their economic efficiency. demining is an inherently expensive process. training sniffer dogs and educating personnel also represent significant financial challenges. however, when considering the overall effectiveness and operational outcomes of the three main methods, mechanical demining proves to be the most economically viable. although the initial budget and resources required to procure a mechanical demining system are substantial, such a system demonstrates long-term cost-effectiveness. a well-functioning system, operating year-round regardless of weather conditions or terrain, with regular maintenance and repairs, becomes a financially sound investment. more importantly, such a system might save even a single human life a value that is truly immeasurable. the economic feasibility of mechanical demining systems is further reinforced by their versatility. many systems can be repurposed for other applications if needed. for instance, a single system with multiple attachments can be simultaneously utilized for mine-clearing operations and firefighting missions, thereby further justifying its economic value [1]. using advanced systems such as mechanical demining paired with advanced detection technologies can significantly improve the cost-effectiveness and efficiency of mine action programs. here's how these methods compare to traditional approaches. cost-efficiency:  reduced labor costs: advanced technologies reduce reliance on manual deminers, who require extensive training and are often the most significant recurring cost in demining operations.  faster clearance rates: mechanical systems like flails, tillers, and excavators can clear larger areas more quickly, reducing the time and, consequently, the overall costs of operations.  precision from advanced detection: technologies like ground-penetrating radar (gpr), drones with multispectral imaging, and ai-enhanced metal detectors minimize false positives, saving time and resources. dss vol. 6, no. 1, 2025, pp.1-24 3 enhanced safety:  minimized risk to humans: mechanical systems and autonomous vehicles reduce the need for personnel to work in close proximity to landmines, decreasing the risk of injury or death.  improved detection accuracy: advanced sensors reduce the likelihood of missed mines or unnecessary excavation caused by false positives, making the process safer and more predictable. for example here is a comparison between traditional and advanced system demining, and although it costs more at the beginning, on a larger scale, where minefields are on a wide spread of an uneven and hard-to-reach terrain, mechanical demining is more cost-effective.  traditional methods: manual demining can cost $1–$4 per square meter and take years for heavily mined areas.  advanced systems: costs range from $2–$10 per square meter initially but scale better in larger operations due to increased efficiency and time savings [2]. it is also worth noting that, since the entire study is primarily based on data collected from the territory of bosnia and herzegovina, where minefields are located in particularly challenging terrains, the case study has demonstrated that mechanical demining paired with gpr detection has significantly improved the conditions in the field, improving clearance rates in regions with heavy contamination. 3. multifunctional and multimodal solutions available on the market year after year, demining systems continue to improve, particularly those that perform simultaneous detection and clearance, thereby increasing their level of efficiency. the market for mechanical demining systems is not significantly diverse when it comes to the applied methods, which are primarily based on milling systems and digger systems. the key differences lie in the total effective width of operation and the depth of excavation. detection system technology plays a pivotal role in enhancing clearance systems. with advancements in technology and the application of ai software for data analysis, it is possible to create highly detailed vehicle navigation maps with minimal deviations. it is important to note that civilian and humanitarian demining systems are essentially derived from military demining systems, which have been further refined to enhance their efficiency. this distinction forms the basis of the differences between military and humanitarian demining. according to the international mine action standards (imas), based on united nations (un) guidelines, humanitarian demining must achieve an accuracy rate of 99.6%. therefore, demining systems, particularly those dedicated to humanitarian demining, must be designed to meet international imas standards to ensure the highest possible efficiency. over the past two decades, the market for demining machines has seen the emergence of so-called modular platforms or modular vehicles. these serve as base stations to which specific attachments such as mechanical demining systems can be connected. the advantage of such systems lies in their efficiency and cost-effectiveness, as previously mentioned since they can be reallocated and adapted for other purposes depending on the need. the most common applications of these systems are as follows. 1. military operations. military applications have continued to drive innovation in ugv (unmanned ground vehicle) technology. the gulf war in the early 1990s highlighted the need for unmanned systems to perform dangerous tasks such as bomb disposal and reconnaissance. this led to the development and deployment of ugvs such as irobot's pack bot and foster-miller's talon. these ugvs were extensively used in conflicts in iraq and afghanistan for tasks like detecting and neutralizing improvised explosive devices (ieds). 2. civil and commercial use. in recent years, ugvs have found applications across various civilian and commercial sectors. in agriculture, ugvs are used for precision tasks such as soil analysis, planting, weeding, and harvesting, ensuring high efficiency and accuracy. in the logistics industry, ugvs dss vol. 6, no. 1, 2025, pp.1-24 4 automate warehouse operations, transport goods, perform inventory checks, and manage logistics. in the construction industry, ugvs are employed for tasks such as surveying, material transport, and heavy equipment management, improving both safety and productivity. 3. humanitarian and rescue missions. ugvs have also proven invaluable in humanitarian efforts and disaster response. they are deployed in disaster zones for search and rescue operations, debris removal, and supply delivery. their ability to operate in hazardous environments makes them essential for tasks too dangerous for human rescuers. for instance, ugvs were heavily utilized following the fukushima daiichi nuclear disaster in japan for damage assessment and cleanup operations in areas with high radiation levels. dok-ing mv-4 (fig. 1) is one of the world's most renowned light-class robotic systems, designed for demining operations and explosive ordnance disposal (eod). its low profile and robust structure make it highly resistant to detonations from all types of anti-personnel mines and uxos of similar explosive intensity. additionally, it is capable of withstanding explosions from anti-tank mines. figure 1. dok-ing mv-4 [7] home x howe thermite robotic firefighters (fig. 2) are among the most capable and durable firefighting robots on the market. designed to mitigate life-threatening situations, these tools provide fire suppression, situational awareness, and intelligence gathering for first responders. thermite robotic firefighters are essential allies in high-risk, hazardous environments. figure 2. howe x howe robotic ugv [8] the aardvark gen 2 (fig. 3) is an advanced unmanned ground vehicle (ugv) specialized in humanitarian demining and other demanding engineering tasks. developed by aardvark clear mine ltd, this system is designed to deliver a high level of safety and efficiency in mine clearance operations. dss vol. 6, no. 1, 2025, pp.1-24 5 figure 3. aardvark gen 2-concept [9] milrem robotics multiscope ugv (fig. 4) is a fast, cost-effective, and flexible solution for the mining sector, helping companies keep workers away from hazardous locations while saving time and energy. the ugv can be remotely operated to access dangerous areas or utilized for automated transport of heavy equipment and materials. figure 4. milrem robotics multiscope ugv-firefighting ugv [10] textron ripsaw m5 (fig. 5)combines the speed of innovation with proven program performance, making it combat-ready. as the 5th generation of the ripsaw series, the m5 delivers speed, mobility, and unmanned capability. it can maneuver silently and keep pace with current and future maneuver forces, pushing capabilities beyond human formations. figure 5. textron ripsaw m5 ugv platform [11] dss vol. 6, no. 1, 2025, pp.1-24 6 3.1. ugv (unmanned ground vehicles) unmanned ground vehicles (ugvs) are robotic systems that operate on the ground without human presence. they can be remotely controlled or operated autonomously, utilizing various sensors and control algorithms for navigation and task execution. ugvs come in diverse shapes and sizes, tailored to specific applications, ranging from small, portable reconnaissance robots to large, rugged vehicles for heavy-duty tasks. these vehicles are equipped with advanced technologies such as gps, lidar, cameras, and communication systems, enabling efficient operation in various and often challenging environments [1]. 3.1.1. history of ugv (unmanned ground vehicles) early beginnings the concept of unmanned vehicles dates back to the early 20th century. one of the first recorded uses of unmanned vehicles occurred during world war i with the development of remotely controlled tanks and torpedoes. these early systems were primitive by today’s standards but laid the foundation for future innovations. world war i and the interwar period during world war i, the british army experimented with the “wickersham land torpedo,” a remotely controlled explosive device. although it was not widely adopted, this early experimentation demonstrated the potential of unmanned ground systems for military applications. during the interwar period, several nations continued to develop remotely controlled vehicles, primarily for military purposes. the most notable among them was the german goliath tracked vehicle, used during world war ii. it was a small, wire-guided vehicle designed to deliver explosives to enemy positions. modern era: 1990 to present the modern era of ugv development began in the 1990s, with significant technological advancements and a broader range of applications beyond the military. progress in electronics, computing, and sensors has enabled the development of more sophisticated and capable ugvs. 3.2. use of ugvs in humanitarian demining the modern approach to addressing the problem of landmines and explosive remnants of war (erw) worldwide increasingly relies on the application of unmanned ground vehicles (ugvs). these systems offer significant advantages in efficiency and safety, particularly in the context of humanitarian demining. ugvs provide essential functionalities that enhance the demining process. the application of ugvs in humanitarian demining is following: 1. minefield detection ugv systems equipped with advanced sensors (for detecting metal, heat, or explosive substances) enable rapid and precise mapping of minefields, eliminating risks to human lives. 2. explosive device neutralization ugvs with specialized manipulators allow for the safe removal or neutralization of mines and erw, ensuring high precision and safety during operations. 3. terrain mapping ugv systems facilitate detailed mapping of minefields, recording data on the locations of mines and explosive devices, thereby streamlining the planning and execution of demining operations. the advantages of ugvs are numerous. in mine action operations, ugv systems offer a rather broad spectrum of benefits: 1. enhanced operational efficiency by performing multiple tasks simultaneously. 2. reduced human exposure to hazardous environments. 3. increased adaptability, as the same ugv base can be repurposed for different missions. dss vol. 6, no. 1, 2025, pp.1-24 7 their utility extends beyond demining. analysis of existing innovative systems in the market reveals a wide range of applications, particularly in civil protection. ugvs have become indispensable in various aspects of civil protection, including: 1. search and rescue ugvs are deployed to locate individuals endangered by natural disasters such as earthquakes, floods, or hurricanes. their ability to access hazardous or hard-to-reach areas makes them invaluable tools for saving lives. 2. firefighting equipped with sensors for detecting fires and hazardous gases, ugvs enable firefighters to respond rapidly and manage fires more effectively. 3. disinfection ugvs can be employed to disinfect public spaces or surfaces in response to outbreaks of infectious diseases, such as covid-19. their autonomy ensures efficient disinfection without exposing humans to risk. by integrating ugvs into these critical operations, organizations not only enhance safety and efficiency but also leverage advanced technology for broader societal benefits. 3.2.1. efficiency and reliability of ugvs efficiency the efficiency of unmanned ground vehicles (ugvs) pertains to their ability to perform tasks with minimal loss of time, energy, and resources. key factors influencing efficiency include: 1. energy management efficient ugvs optimize battery usage and energy consumption. advanced energy storage systems and regenerative braking are common features that enhance energy efficiency. 2. navigation and path planning advanced navigation systems utilizing algorithms for optimal route planning reduce travel time and energy consumption. techniques such as simultaneous localization and mapping (slam) are widely applied to improve navigational efficiency. 3. task execution ugvs equipped with multifunctional tools can perform various tasks without the need for equipment replacement, thereby enhancing overall task efficiency. reliability reliability is a critical aspect of ugv performance, particularly in applications where failure can have significant consequences. reliability encompasses the ability of a ugv to consistently perform its intended functions under specified conditions. key factors include: 1. mechanical reliability this involves the robustness of a ugv’s physical components, including the chassis, wheels, tracks, and manipulators. studies have shown that mechanical failures, such as those related to propulsion systems or actuators, are common but can be mitigated through regular maintenance and robust design. 2. reliability of sensors and control systems reliable sensors and control systems are essential for accurate navigation and operation. failures in these systems can lead to navigation errors or issues in task execution. advances in sensor fusion and fault-tolerant control systems have significantly enhanced the reliability of these critical components. 3. communication reliability for teleoperated ugvs, reliable communication systems are essential. issues such as signal loss or interference can disrupt operations. improvements in communication technology, including the use of redundant communication channels, have been implemented to address these challenges. dss vol. 6, no. 1, 2025, pp.1-24 8 4. conclusion on designing an innovative ugv system the future of addressing tasks that carry significant risks to human safety and have the potential to cause unnecessary consequences on the ground lies in the implementation of autonomous or teleoperated (remotely controlled) systems such as ugvs (unmanned ground vehicles). additionally, the future of vehicles designed for executing specialized missions also resides in the ugv segment. investments in the scientific and design aspects of ugv development will ensure easier operation and execution of more complex missions, particularly those involving direct human danger. integrating ai technology into autonomous navigation will enhance the operational effectiveness of ugvs while also improving control systems. this positions the human operator as a supervisor overseeing the entire operation, whether it be humanitarian demining, rescue missions, firefighting, or similar tasks. power systems and propulsion in ugvs analyzing current market solutions, we gain valuable insights into the power supply and propulsion mechanisms of ugvs, which form the vehicle's core and are crucial for uninterrupted mission execution. despite the global industry's gradual shift towards complete electrification to reduce co2 emissions, ugv propulsion systems must retain fossil fuel-based power sources, particularly for applications such as humanitarian demining or rescue missions, where uninterrupted power supply is vital. the rationale is straightforward: in remote and challenging locations far from communication networks, it is more practical to deliver one ton of fuel than to install electric cables spanning hundreds of meters or even kilometers. key design principles for innovative ugv solutions the design of an optimal and innovative ugv system can be summarized into five key points: 1. vehicle dimensions compact vehicle dimensions that allow passage through dense vegetation and rugged terrain, comparable to the size of an average off-road vehicle, are essential for accessibility. 2. modular platform a modular platform enhances cost efficiency for repairs and maintenance, facilitates multifunctional use depending on the installed module, and accelerates development time by treating each segment as an independent module (e.g., propulsion, power, or operational module). 3. versatility in missions a thoughtfully designed platform capable of handling a wide range of tasks, including military operations, civil applications, humanitarian missions, and rescue operations, ensures adaptability. 4. vehicle as a power station ugvs powered by internal combustion engines, combined with electric generators, can serve as mobile power stations during natural disasters. 5. development for future use applying the modular principle to smaller vehicle segments allows for future development and expanded application. innovative development in collaboration with federal civil protection the development and research process for creating this innovative solution was conducted in collaboration with the federal administration of civil protection, specifically the demining and explosive ordnance disposal sector. this partnership led to the realization of a multifunctional solution suitable for a variety of missions and tasks, or alternatively, as a power supply unit. feedback from trained personnel with decades of experience in mine action operations played a critical role in identifying both innovative and efficient methods for mechanical demining, particularly in challenging terrains with complex topography, such as those found in bosnia and herzegovina. below is an illustration of the conceptual design (final sketch) that led to the further development of the modular ugv platform. dss vol. 6, no. 1, 2025, pp.1-24 9 figure 6. ideation sketch that was the final stage of the final design 5. development of the ugv modular platform by defining the ugv design through sketches and developing each element of the modular platform, we advance to the next stage of design and development: constructing a 3d software model. the 3d software model provides a comprehensive view of the vehicle's form, allowing us to make necessary adjustments to enhance functionality. as mentioned earlier, the design follows the principle of a modular ugv platform. in line with this principle, each element or module is modeled individually in 3d before assembling the final model. figure 7 features numbered modular platform elements. dimensions are presented in fig. 8. figure 7. the final design of ugv modular platform-modular segments 1. main load-bearing platform the foundational structural element that supports all components of the ugv, ensuring stability and strength during operations. 2. central drive system the core propulsion system responsible for powering the vehicle is equipped with robust engines or motors suitable for varied terrains and tasks. 3. protective roof covering a shield that safeguards internal components from environmental hazards and potential impacts. dss vol. 6, no. 1, 2025, pp.1-24 10 4. module base a modular framework designed to securely house interchangeable mission-specific components. 5. protective bullbar with integrated radars, scanners, and cameras a front-mounted protective structure equipped with advanced detection and navigation technologies to enhance situational awareness and operational safety. 6. v-hull (external module for blast wave deflection) an externally mounted feature designed to deflect explosive shockwaves away from the vehicle, providing additional safety in hazardous conditions. 7. other vehicle parts (lights, supplemental radar systems, ladders, etc,) ancillary components that enhance the vehicle's functionality and operational flexibility. 8. vehicle structure the overall framework that integrates all components is designed to provide durability, balance, and adaptability. figure 8. dimensions of the ugv vehicle by finalizing the decision to develop a ugv modular platform, the focus on modularity ensures both costeffectiveness in production and accelerated development timelines. the platform is divided into subunits, with each part treated as a separate module. this approach not only expedites the development process but also simplifies the replacement and modification of specific components. one of the critical reasons for adopting a modular design and development approach is to streamline repairs, maintenance, and replacement of individual segments, ultimately extending the product's lifespan. for instance, if the front section of the vehicle, such as the bullbar, sustains damage, there is no need for a comprehensive repair or replacement of the entire vehicle. instead, only the damaged part in this case, the front protective bullbar would be replaced. this modular design philosophy significantly enhances the platform's practicality, adaptability, and long-term operational efficiency. dss vol. 6, no. 1, 2025, pp.1-24 11 5.1. technical specifications of the ugv modular platform during the 3d software modeling process of the ugv, the primary focus was placed on the vehicle's compactness. since the ugv is intended for deployment in extremely challenging terrains and hard-to-reach locations, compactness was emphasized not only in the vehicle's dimensions but also in its overall architecture, including the propulsion and generator systems, as well as the hydraulic system. in the illustration below, the total dimensions of the vehicle are shown, which correspond to the average size of a passenger car commonly seen on roads. the designed ugv's dimensions do not exceed the standard road lane width (2.5 meters).this compact design ensures the ugv's adaptability and maneuverability in confined or difficult-to-access environments while maintaining efficiency and functionality. 5.1.1. structural development of the ugv modular platform the design of the ugv vehicle was based on the principle of modularity, applied to the vehicle's operational framework as the core platform (base station). the vehicle's architecture was tailored to the modular principle, meaning the vehicle is composed of modules to facilitate easier troubleshooting, part replacement, and regular maintenance. the vehicle's construction (fig. 9) adhered to the modular approach and was divided into several components: 1. base structure: the primary load-bearing and structural element—this part of the construction handles the heaviest loads. 2. sub-structure: a structure mounted onto the base structure, serving as a framework for attaching panels and specific components necessary for the vehicle's full functionality. figure 9. structural development, the first version of the ugv structure the development of the structure is tailored to the segments and the final design of the modular ugv platform, along with all its associated components, as previously outlined. the structure was designed based on the principle of triangle application to ensure uniform distribution of load forces. the final version of the construction, after a series of adaptations and various technical and technological implementations, was built using hot-rolled steel u-profiles with dimensions of 100x50x5 mm. the reason for selecting already existing profiles was to influence the manufacturing time, economic feasibility of both the construction and the entire project, and, most importantly, the reduction in weight, which can significantly affect the vehicle's final performance. after selecting the profiles, a series of adaptations to the initial construction were made, followed by the generation of a 3d model of the structure for visualization, technical documentation preparation, and model preparation for numerical (fea) analysis. using software for generating and numerically analyzing the 3d model (solidworks), an fea analysis was conducted. upon detailed review of the fea analysis, certain dss vol. 6, no. 1, 2025, pp.1-24 12 adaptations to the model were necessary. after the modifications, the analysis results showed passing results with maximum loads of up to 15 tons, which is three times higher than the nominal calculated operational load on-site. the static analysis of the final version of the construction is performed in three phases (figs. 10-12), addressing the three most critical possible scenarios for the fixation of the structure:  4 fixations (all 4 wheels touching the ground),  3 fixations (3 wheels touching the ground, 1 wheel in the air),  2 fixations – diagonal (2 wheels touching the ground, 2 wheels in the air). the most critical phase is the 2/2 variant, where 2 fixations are diagonal, as this is when the maximum twisting of the structure occurs. this is where the largest displacements in the fea analysis (figs 13 and 14) are most evident. figure 10. analysis in the case of 4 fixations figure 11. analysis in the case of 3 fixations figure 12. analysis in the case of 2 diagonal fixations dss vol. 6, no. 1, 2025, pp.1-24 13 figure 13. displacement of construction in static analysis with 2 diagonal fixations figure 14. the strain of construction in static analysis with 2 diagonal fixations figure 15. the stress of construction in static analysis with 2 diagonal fixations dss vol. 6, no. 1, 2025, pp.1-24 14 the final version of the construction is presented in figs 16 and 17 (back and frontal view). figure 16. the final version of the construction (back view) figure 17. the final version of the construction (frontal view) 5.1.2. propulsion system of the ugv modular platform the propulsion system of the ugv (unmanned ground vehicle) utilizing an internal combustion engine (ice) represents a robust and efficient solution for operations in hard-to-reach areas (fig. 18). these engines are renowned for their ability to deliver high power and reliability, even under extreme conditions such as low temperatures, dusty or muddy terrains, and steep gradients. the internal combustion engine is paired with a generator that converts the engine's mechanical energy into electrical energy. this generator powers the vehicle's electrical components, including sensors, communication equipment, and auxiliary systems, thereby enhancing the ugv's autonomy and operational range. additionally, the integration of the ice with a generator enables the vehicle to supply electrical power in emergency situations, addressing the energy needs of remote settlements or critical institutions requiring a stable power supply. this dual functionality significantly increases the versatility and utility of the ugv platform in various mission scenarios. figure 18. propulsion system of ugv modular platform, sectional view, internal combustion engine paired with electric generator dss vol. 6, no. 1, 2025, pp.1-24 15 the advantages and benefits provided by an internal combustion engine (ice) as a propulsion system, as previously noted, lie in its effectiveness during critical situations where uninterrupted vehicle operation is essential for the success of a specific action or mission. another significant advantage is the closed-system design, allowing repairs and urgent maintenance to be performed directly in the field if necessary. this feature enables parts from one vehicle, damaged during an operation, to be transferred and utilized in a less-damaged vehicle. the development of the vehicle's structure is another distinct segment of the design process, critical for the serial production of such systems. due to the confidentiality of data related to the comprehensive development and structural analysis, this aspect will be omitted from the scope of this scientific paper. however, it is worth noting that the structure has been tailored to align with the overall design and developed in accordance with the active loads that may occur during specific operations or missions in challenging terrains. 5.1.3. characteristics of the ugv vehicle after defining the objectives, as well as the design and development of the base platform, the vehicle's power transmission systems to the ground are included among its key characteristics. most production vehicles currently available on the market utilize tracked systems for power transmission to the ground, which is the most efficient solution for off-road vehicles of this type. however, as this work focuses on the design and development of an innovative solution aimed at ensuring seamless or facilitated functionality and operability on terrains with more demanding topographies, in addition to the traditional tracked power transmission system, a so-called robotic arm system is being developed. this system includes independently powered wheels at each of the vehicle's four drive points, enhancing its adaptability and performance in challenging environments. 5.1.3.1. track-based power transmission system the track-based power transmission system is one of the most economical and efficient methods for transferring power to the ground in off-road vehicles. in addition to providing excellent traction on various surfaces, tracks enable the vehicle to overcome steeper inclines, which conventional off-road tires cannot achieve. the ugv is equipped with 35 cm wide rubber tank tracks, driven by two high-torque electric motors. this configuration (fig. 19) ensures exceptional traction in all situations and across diverse types of terrain. figure 19. side view of ugv modular platform with track-based power system through the development of a modular system, we successfully lowered the center of gravity of the modular platform closer to the ground. this adjustment benefits the vehicle, particularly when utilizing the track-based power transmission system. with this improvement to the center of gravity (fig. 20), we achieved enhanced stability, allowing for increased tilt angles of the vehicle, including lateral tilt angles as well as the approach and departure angles at the front and rear of the vehicle. dss vol. 6, no. 1, 2025, pp.1-24 16 figure 20. approach, departure, and tilt angles 5.1.3.2. power transmission system using robotic arms with independent power supply and integrated in-wheel motors the power transmission system based on robotic arms with an integrated in-wheel motor system offers several advantages when operating on challenging terrains: 1. increased ground clearance this system allows for dynamic adjustment of the vehicle's ground clearance, enabling it to traverse obstacles and rough terrain more effectively. 2. extended wheelbase (stability) by extending the distance between axles when needed, the system enhances vehicle stability on uneven surfaces. 3. on-site servicing and repairs the modularity of the robotic arms facilitates repairs and maintenance directly in the field, minimizing downtime during missions. 4. independent power supply for each wheel each wheel is powered separately, enabling adaptive traction control and directing power to the wheels with the most grip for improved performance in challenging conditions. 5. in-place rotation the robotic arms (fig. 21) and in-wheel motors allow the vehicle to execute precise, on-the-spot maneuvers, including 360° rotation, greatly enhancing mobility in constrained environments. figure 21. side view of ugv modular platform with robotic arm power system with integrated in-wheel ev motors robotic arms, in addition to the in-wheel system, are also equipped with airless tires, which are highly suitable for this type of vehicle (fig. 22). airless tires are systems with an internal structure composed of a network of reinforced rubber elements, providing additional suspension to the vehicle. unlike conventional pneumatic tires, which require repair in the event of punctures, airless tires can overcome obstacles without the risk of bursting. furthermore, damage to the sidewalls of airless tires does not affect the vehicle's operational capacity as it would with conventional tires. consequently, the lifespan of airless tires is significantly longer. dss vol. 6, no. 1, 2025, pp.1-24 17 figure 22. detailed view of robotic arm power system independent power supply for the robotic arm system and their independent rotation at the articulated joint with the platform allow for adjustments to the vehicle's height (joint rotation angle of up to 85°). the vehicle can increase its ground clearance within a range of 2.2 m to 4.2 m (fig. 23). this capability, combined with unrestricted movement, enables the vehicle to position itself on any incline and overcome specific depressions, protrusions, or obstacles in the terrain when required. figure 23. ugv modular platform with variable height 6. modules for ugv operations in the previous sections, we elaborated on the three primary domains where ugv modular platforms and vehicles are applied. with this in mind, we design and develop modules necessary for performing specific operations and tasks. the following modules are being developed: 1. multi-functional robotic arm module with interchangeable tools 2. mechanical demining module – variable flail mechanism 3. mechanical demining module – independently positioned flails and milling mechanism 4. firefighting module – water cannon since the ugv modular platform is equipped with a generator paired with an internal combustion engine (ice), it is capable of generating electrical power. beyond serving as a power station during emergencies—such as natural disasters causing interruptions in electricity supply—the platform can also function as a charging station for drones, as well as a take-off and landing station. with this in mind, we design a drone capable of carrying loads of approximately 80 kg. however, in reference to our earlier research [6], the drone's primary role is to detect landmines, minefields, and unexploded ordnance. it is equipped with detection systems such as nqr (nuclear quadrupole resonance) or lidar. additionally, the drone can be outfitted with infrared cameras and systems for detecting fires or locating missing persons in difficult-to-access terrains. modular attachment system before discussing the designed modules, it is important to briefly explain the module attachment system (fig. 24), which is critical for the seamless, efficient, and rapid deployment of a single vehicle to the field. modules are connected to the vehicle via a rotating turret located at the front of the vehicle. this turret has a load capacity dss vol. 6, no. 1, 2025, pp.1-24 18 of over 5 tons and includes hydraulic and electrical connectors to power the modules. the module attachment turret is angled at 15° to avoid any potential conflicts during the rotation of the module's arm, ensuring smooth and efficient operation. figure 24. module attachment system, rotary turret different types of modules, when not in use, are stored on a docking structure located within the facility. the modules are secured to the structure using hydraulic clamps. once the vehicle approaches the desired module needed to perform a task or mission, the hydraulic clamps release the module, allowing it to be lowered into the docking turret on the vehicle, as shown in figure 25. figure 25. construction for storing modules with a mechanical gripper fixation system dss vol. 6, no. 1, 2025, pp.1-24 19 6.1. multifunctional robotic arm module with interchangeable end the multifunctional robotic arm module (fig. 26) is designed to provide full control and maximum mobility, closely resembling the system of an excavator arm. however, in this specific case, the module features independent rotation at its base, relative to the vehicle’s position. it is also equipped with a central telescopic system with a maximum extension of up to 3 meters. with the ability to change its end-effector, the module can be easily repurposed. in addition to a digging bucket, it can be equipped with a hydraulic breaker for construction purposes, a water cannon for firefighting, or a winch for lifting loads. the image below illustrates the operational angles of all joints, along with their maximum rotations. figure 26. side view of multifunctional robotic arm module with interchangeable end, operative movements of the joints 6.2. mechanical demining module – the principle of variable flails the mechanical demining module (fig. 27) operating on the principle of variable flails essentially involves the independent movement of flails along the z-axis (fig. 28). these flails are divided into three independent systems, which can be positioned relative to one another autonomously. a key innovation of this system is its ability to adapt to terrain, enabling the complete mechanical removal of mines in depressions and protrusions, thus increasing operational efficiency in challenging environments. the system operates based on previously scanned areas, utilizing detection systems carried out by drones. these drones perform topographical scans of contaminated terrain, detecting mines and creating a 3d terrain analysis. this analysis guides the positioning and movement of the flails, ensuring precise and efficient demining. figure 27. side view of mechanical demining module, operative movements of the joints dss vol. 6, no. 1, 2025, pp.1-24 20 figure 28. front view of mechanical demining module, detailed view of height adjustment by simultaneously combining detection and mechanical mine and uxo (unexploded ordnance) removal, the data accuracy and applicability are ensured, preventing unnecessary issues or critical situations in the field that could compromise the functionality of the vehicle or endanger personnel. this approach addresses potential terrain changes, as topography at specific sites can shift, leading to the displacement of mines or uxos. this displacement is often caused by soil erosion due to heavy rainfall, which may result in landslides that further bury or shift mines and uxos. the presented system integrates detection using lidar technology (fig. 29), allowing real-time terrain scanning and mine detection. this setup aligns with the research detailed in our earlier paper [6], which highlights the advantages of such integrated systems. the illustration below demonstrates the system's operational method, showcasing its synergy with simultaneous mine detection using lidar. figure 29. principle of operation of the module for mechanical demining (principle of variable flail system) integrated with lidar scan of ground and detection of landmines and uxo dss vol. 6, no. 1, 2025, pp.1-24 21 6.3. mechanical demining module – the principle of independent positioning of flails and tiller the mechanical demining module (fig. 30), which operates on the principle of independent positioning of the flails and the rotary cutter, allows for various work speeds and different digging depths. the primary role of mine destruction is assigned to the chain mechanism, i.e., the flail system. the rotary cutter, as the secondary system, is there to complement any gaps that may arise during the mechanical removal of the flail system. independent positioning and movement of the flails and rotary cutter in relation to the digging depth provide greater efficiency compared to the classic arrangement with two flails. the combination of the flails and the rotary cutter provides certain advantages when digging different types of soil. according to the demining requirements, the digging depth and the number of rotations are adjusted to achieve a higher technological speed and better operational efficiency. each segment of the cutter rotor can have multiple heads positioned at a relative angle of 120°. the segments are phased so that the cutting heads form three spirals that begin from the center of the rotor and symmetrically expand to each side [1]. destruction of high-destructive power mines must be carried out by the primary tool – the chain mechanism with a large radius, which will not be damaged. the rotary cutter, as the secondary tool, is suitable for adjusting the digging depth and fully clearing the mines. in short, the combination of the flail system as the primary and the tiller system as the secondary tool provides the following advantages: 1. more flexible handling of different working conditions with two independent working tools. 2. the ability to independently adjust the digging depth and the number of rotations of flail and tiller. 3. adaptation to actual demining conditions. 4. two tools, the flail, and the rotary cutter, provide double efficiency. 5. high reliability in the destruction of different types of mines. 6. the most destructive anti-tank mines are destroyed by the chain mechanism, avoiding significant machine damage. 7. the rotary cutter is lighter than the second flail, saving material and motor power. 8. the rotary cutter destroys the smallest parts. 9. the rotary cutter can be adjusted to determine the final digging depth of the soil. [4] figure 30. side view of mechanical demining module, operative movements of the joints the combination of a tiller system and flail system in mechanical demining does not require special terrain analysis and topographic scans, as in the case of the variable flail principle. the system works by positioning the flails relative to the rotary cutter, or the rotary cutter relative to the flails, depending on the terrain and soil composition, in order to increase the effectiveness of mine and uxo removal, which may be buried or further covered with soil deposits during the mechanical removal process. the system can also be paired with airborne terrain scanning for the presence of mines and uxos, and, using the detection system, generate a detailed movement path for the vehicle. dss vol. 6, no. 1, 2025, pp.1-24 22 figure 31 shows the principle of mechanical demining using a system of independent positioning of flail and tiller system, integrated with aerial drone multi-sensor detection systems, such as lidar and gpr sensors. figure 31. principle of operation of the module for mechanical demining (principle of independent positioning of flails and tiller), integrated with aerial detection sensors for landmines and uxo dss vol. 6, no. 1, 2025, pp.1-24 23 figure 31 shows how can smart algorithms predict the exact movement of the ugv to the exact location where the mines are placed. with the modern approach, first of all, landmine detection systems, which are a crucial part of mechanical demining, the percentage of success of mine action programs is significantly higher, up to 50%. mechanical demining based on the principle of independent positioning of the flail and tiller system, works by adjusting the depth of digging each tool. for example, the primary tool is the flailing system, used for the unveiling, digging out the soil around the landmine, as well as destroying it. the secondary tool, the tiller system is there to fulfill possible fails of the flailing system, such as that mine can be much further buried, or the remains of the landmines after detonating. the flail system will destroy every bits and pieces of the landmine. 6.4. water cannon module for firefighting the water cannon module (fig. 32) designed for firefighting purposes enhances the versatility of the ugv platform, positioning it primarily as a tool for protecting both people and the environment. the advantages of using such systems in firefighting lie mainly in preventing potential injuries or fatalities during operations involving highly dangerous fires, particularly in structural fires where the collapse of buildings or their structural elements could pose additional risks to personnel on site. ugv systems in firefighting are not a new concept; robotic ugv systems of smaller dimensions have been used over the past decade, primarily as firefighting tools directly connected to a water hose supplied by a fire truck. the system discussed here operates in two modes: it can either connect directly to a fire truck or a hydrant as a water source or utilize its onboard reservoir, with a capacity of 5 tons, for water or foam. having an onboard reservoir for water or foam allows the ugv system to operate effectively in critical areas, such as structural fires or fires in terrains with challenging topographies. in such scenarios, the vehicle would be remotely controlled from a safe distance for personnel and equipped with thermal cameras to identify and suppress any "hidden" hotspots in the fire. figure 32. water cannon module attached to a tracked ugv modular platform with red-white livery 7. conclusions the implementation of ugv systems in the domain of demining represents a crucial innovation in addressing one of the most serious humanitarian challenges – unexploded landmines. the application of mechanical demining, combined with the innovative system of mechanical demining with independent positioning of flails and tillers, brings significant improvements in efficiency and safety during demining operations. this advanced dss vol. 6, no. 1, 2025, pp.1-24 24 approach allows precise control over the tools and provides greater flexibility in operational conditions, reducing risks to human life and accelerating the land clearance process. the ugv modular platform designed in this work adds further value to mine action efforts, as its modularity allows for easy adaptation to different operational requirements and specific working conditions. with the ability to integrate various modules, the platform can be tailored for use in different scenarios, not only for demining but also for civil protection tasks such as responding to natural disasters, search and rescue operations, and other operations requiring high precision and safety. furthermore, the implementation of such systems in industry can contribute to technological advancement, stimulate innovation, and enhance the economic efficiency of a country. by introducing ugv platforms into various sectors, such as environmental protection, construction, and even defense, competitiveness is increased, and infrastructure is improved. in this way, ugv platforms can become a key factor in advancing industry and the economy, while also contributing to the safety and well-being of society as a whole. funding information no funding was received from any financial organization to conduct this research. declaration of competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. references [1] d. mikulic, design of demining machines, springer, 2013. [2] e. gebrehiwot, h. kara, economics of landmines and demining, naval postgraduate school; mba professional report; monterey, california, june 2009. [3] p.n. nguyen-huu, j. titu, reliability and failure in unmanned ground vehicle (ugv), grrc technical report 2009-01, university of michigan, usa, february 2009. [4] hma global sops chapter 8: mechanical demining, december, 2018. [5] a handbook of mechanical demining, geneva international centre for humanitarian demining (gichd), july 2009. [6] d. cosic, a. catovic, "research on the problem of landmines and explosive remnants of war worldwide and methods of demining", defense and security studies, vol. 5, no. 2, pp. 84-107, nov. 2024. [7] mechanical mine clearance systems, available at: https://www.scopex.fr/en/products/mv4-c-ied-roboticsystem/?marque=15185 [8] howe & howe technologies guide, available at: https://www.thebigredguide.com/news/co/howe-howetechnologies.html [9] aardwarkgroup, available at: https://aardvark.group/gen2/ [10] milrem robotics firefighters, available at: https://milremrobotics.com/milrem-robotics-and-innovfoamdevelop-robotic-firefighters-2/ [11] textron systems m5 ripsaw, available at: https://www.textronsystems.com/products/ripsaw-m5 [12] d. cosic, design of ugv modular platform for human demining and civil protection mission – concept design, master thesis, academy of fine arts, university of sarajevo, 2024. microsoft word 112-121_292.docx (online) issn 2744-1741 defense and security studies original research vol. 6, no. 2, 2025, pp.112-121 https://doi.org/10.37868/dss.v6.id292 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 112 advancing sustainable development goals in aerospace industry through industry 5.0 sachin srivastava1*, abhay dhasmana2, aditya singh rana3, ankitha satheesh4, k. lipidharan5, vineet rawat6, shivam yadav7 1,2,3,4,5,6,7 department of aerospace engineering, uttaranchal institute of technology, uttaranchal university, dehradun-248007, india *corresponding author e-mail: sachinrash2004@gmail.com received: sep. 9, 2025 revised: oct. 2, 2025 accepted: oct. 3, 2025 online: oct. 3, 2025 abstract the aerospace manufacturing industry is facing increasing pressure to align with the united nations' sustainable development goals, such as responsible production, climate action, and industry innovation. industry 4.0 notwithstanding, most of these technologies are concerned with efficiency and automation while paying little heed to human-centric, sustainable goals that can be achieved in line with the sdgs. this would present a possibility to bridge this gap with industry 5.0, which is on the way to collaborating with human-machine interaction and sustainability practices. this paper discusses the possibility of how this new paradigm, focused on collaborative work between advanced automation and human-centric, sustainable production, can help aerospace manufacturers achieve those key sustainable development goals. industry 5.0 will provide an opportunity for a symbiotic partnership between humans and machines with avenues that open opportunities to reduce environmental impacts, optimize the use of resources, and enhance innovation in aerospace manufacturing processes. the research illustrates the implementation strategy of industry 5.0, smart factory, robotics, digital twin, and artificial intelligence towards the achievement of sdg 8, sdg 9, sdg 12, and sdg 13. © the author 2025. published by arda. keywords: industry 5.0, sustainable development goals, aerospace, human and machine 1. introduction 1.1 overview of sustainable development goals in manufacturing the united nations' sustainable development goals (fig. 1) have defined the framework for global sustainable development, articulated environmental protection, social equity, and economic growth. sdgs adopted by manufacturing industries mean a transformation toward responsible production practices in order to reduce the consumption of resources and their resultant negative impact on the environment. the holistic evaluation of corporate sustainability calls for a set of performance metrics based on sdgs within the sustainable manufacturing system [1]. because companies increasingly integrate sdg principles within their models of operations, manufacturing systems become more resilient and agile, hence balanced growth of the economy and dss vol. 6, no. 2, 2025, pp.112-121 113 environmental sustainability. manufacturing firms leverage sustainable business models to implement sdgs, thus reducing waste and enhancing resource efficiency [2]. this shift towards sustainability meets the needs of the regulatory bodies and stakeholders alike, while it also provides industries with long-term economic sustainability and resilience. in particular, this is particularly true for environmentally intensive industries, such as aerospace manufacturing. even in the aerospace industry, they are looking for sustainable propellants and technology through industry 5.0. later, scientists and researchers are looking for sustainable rocket propulsion such as a hybrid rocket, which is an intermediate between a solid and liquid rocket engine [3-5]. it will add the new scope to reach a low earth orbit and replace the expensive space mission with an affordable price. fig. 1 sustainable development goals 1.2 evolution of industry 4.0 to 5.0 in aerospace the industry 4.0 shift towards industry 5.0 has significantly impacted the aerospace industry, marking an industrially dynamic change in industrial practices. industry 4.0 thrusts digitalization and connectivity to the fore, thereby converging iot, big data, and automation in every function of manufacturing. the current step is that aerospace manufacturers have achieved high productivity and efficiency due to interconnected systems and data-driven decision-making [6]. accordingly, the aerospace industry saved processes such as predictive maintenance and higher-quality products. industry 5.0, on the other hand, introduces a system emphasizing human-centricity and sustainable development, reframing the role of technology within industrial frameworks. unlike the fully automated approach taken by industry 4.0, industry 5.0 advocates for cooperative interactions between humans and machines, where the benefits of human creativity and intuition are merged with the machine's precision. such shifts are important in pursuing sustainability and adaptability in these complex manufacturing environments, as found in aerospace [7]. for example, in industry 5.0, humans and machines come together to solve problems and thus provide a more inclusive means of production, with environmental factors considered and worker satisfaction increased. with the help of technological inventions such as digital twins, ai, and robotics, for example, which can accommodate collaborations with humans in real-time environments, industry 5.0 is able to make sustainable manufacturing possible in the aerospace industry. these technologies ensure better resource utilization, waste reduction, and greater safety standards, making this industry meet the sustainability goals [8]. furthermore, the focus on digital transformation provided in industry 5.0 allows an automobile manufacturer to build robust and agile systems that can respond dynamically to rapidly changing demands and operational needs. solutions for the production of aircraft, as well as mro, suggest the impact of industry 5.0 on aerospace. the integration of human-machine collaboration in these processes enhances flexibility and supports innovations in sustainable practices [9]. furthermore, the use of ai-driven frameworks to optimize repair and production timelines aligns well with industry 5.0's focus on productivity and resource efficiency. this change will be sure to herald tremendous changes in both operational sustainability and the quality of human dss vol. 6, no. 2, 2025, pp.112-121 114 engagement in an industrial setting with the introduction of industry 5.0 technologies in the aerospace sector [10-11]. 1.3 role of industry 5.0 in aerospace manufacturing industry 5.0 (fig. 2) was the birth of a new era in sustainable manufacturing by bringing human creativity, ai, and smart technologies together to produce systems that focus on efficiency and environmental responsibility. as opposed to industry 4.0, which was mainly about automation and efficiency, industry 5.0 seeks to introduce much more balance and sustainability. the human-centered approach lies at the heart of industry 5.0; this allows for environments designed for collaboration between humans and machines. such a design not only results in increased productivity but also reduces environmental impact in terms of efficient resource usage and better management of waste [12]. one of the core objectives in sustainable manufacturing for industry 5.0 is to develop a framework that aligns manufacturing processes with global sustainability standards. industry 5.0 offers an outline for moving toward a more sustainable production model as it uses data-driven insight to improve energy efficiency and reduce emissions [13]. industry 5.0 embraces the well-being of its workers and the greatest performance of its operation for this culture of manufacturing. the environmentally concerning impact of industry 5.0 sustainable manufacturing raises concern over the ethical and healthier ways to work [14]. ai and robots in coordination and design with humans avoid redundancies and hazardous exposure within work for human safety purposes and develop an even friendly atmosphere of work. fig. 2 a generic block diagram for industry 5.0 [15] 2. key principles of industry 5.0 in aerospace manufacturing 2.1 human-centric approach a human-centric approach (fig. 3) is a core component of industry 5.0, which involves harmonized advanced technology with human values, experiences, and needs. human-centric ai in industry 5.0 is designed not only for automation but also for enhancing human skills and decision-making within the manufacturing environment [16]. this approach facilitates a more interactive workspace with ai systems working as collaborators and not replacements, allowing the human aspect to maintain control and apply their creativity for high-stakes aerospace projects. such a framework of balancing human-centric innovations with sustainable and inclusive solutions is very important since it promotes a balanced industrial ecosystem that values both social and environmental well-being alongside technological progress [17]. dss vol. 6, no. 2, 2025, pp.112-121 115 fig. 3 human-centered ai in smart manufacturing [18] 2.2 personalization and customization in manufacturing industry 5.0 focuses on high customization of aerospace components with a particular operational requirement using intelligent systems and data-driven designs. there are numerous challenges and opportunities concerning the development of highly customized personalized product-service systems that are able to meet the varied demands of customers without compromising resiliency and sustainability. a level of customization is critical in aerospace manufacturing, wherein components often have to meet multiple standards for many applications [19]. this principle helps in the standardization of mro operations, making the process as flexible and accurate as possible with enhanced aircraft life and safety. 2.3 integration of advanced technologies (ai, robotics, iot, cyber-physical systems) to make industry 5.0 effectively work in aerospace manufacturing, advanced technologies such as artificial intelligence (ai), robotics, internet of things (iot), and cyber-physical systems (cps) must be well integrated (fig. 4). such technologies provide for more significant automation, precision, and adaptability in manufacturing processes, thereby making them intelligent and responsive. explainable ai in industry 5.0 is an essential aspect since it enhances decision-making for aerospace applications, but also helps engineers and operators understand and interpret better the behavior of the machine. the implementation of this kind of explainable ai enhances the transparency of the decisions made by the machines, thereby building trust between humans and machines [20]. the assembly and inspection of composite fuselage panels with precision and flexibility requires high accuracy and flexibility. robotics can be used for an integrated architecture that combines sensing and feedback systems to let robotic arms work in concert with human operators in precise tasks of assembly and quality inspection in real time. this will allow for improved aerospace manufacturing output while increasing robotic accuracy without decreasing human oversight [21]. besides this, iot and sensor networks also significantly contribute to the development of intelligent factories for industry 5.0. the establishment of iot enables the connection of equipment and sensors with control systems with real-time data collection and analysis in aerospace manufacturing facilities. this connectivity supports predictive maintenance, reduces downtime, and optimizes operational efficiency since it gives a holistic view of the manufacturing environment [22]. in addition, these architectures of smart cyber-physical systems are integrating physical manufacturing processes with virtual systems of control, thereby yielding more robust autonomous frameworks in production. in the field of aerospace manufacturing, for instance, this system would ensure that machinery communication has been integrated with proper controls in corresponding software, so therefore dynamic adjustments take place automatically, and all sorts of production processes are optimized. the integration of cps not only increases production efficiency but also concurs with sustainability targets by wasting fewer materials and less energy consumption [23]. dss vol. 6, no. 2, 2025, pp.112-121 116 fig. 4 industry 5.0 integration framework for aerospace manufacturing 2.4 collaboration between humans and machines industry 5.0 is founded on the notion of human-machine collaboration, maximizing the synergy of human creativity and machine precision. it is a framework that is intended to boost productivity and innovation by ensuring that the machine supports rather than displaces human workers. human-machine collaboration in industry 5.0 has transformed manufacturing processes. here, machines can absorb repetitive or complex calculations in such a way that a human concentrates on the creative, analytical, or decision-making task [24]. additive manufacturing is yet another form of human-machine collaboration where a human designer and a machine collaborate to produce complicated and accurate aerospace components. here, machines take care of the technical precision of the manufacturing process while human expertise guides design and innovation. advanced sensors, combined with ai, are embedded into these machines that can function in tandem with human input; hence, the flexibility in collaboration is displayed as they respond dynamically to the changing requirements in the process. such collaboration leads to the error reduction of the process and maximum adaptability, resulting in quicker efficient cycles of production in aerospace manufacturing [25]. 3. implementation of industry 5.0 in aerospace manufacturing 3.1 smart factories and digital twins in aerospace smart factories and digital twins introduce features of more efficient, precise, and adaptable production processes in aerospace manufacturing. well advanced with data analytics, iot, and ai-driven systems, a smart factory is an environment well covered to create highly automated and connected places where machinery, sensors, and control systems are all integrated (fig. 5). real-time monitoring and predictive maintenance mean that aerospace and equipment downtime can be lessened to the best productivity points. a key element, hence in the space industry, can be identified as a digital twin that presents a means of monitoring and optimization of physical assets like aircraft parts throughout their entire life span [26]. digital twins enable one to simulate, analyze, and provide insight into performance problems before they happen, thus enabling proactive maintenance and reducing the risk of in-service failures. digital twins really take this idea of smart factories beyond these concepts by providing an ideal virtual model that could mirror the environment of the physical factory, enabling manufacturers to test, optimize, and refine without interrupting production processes [27]. digital twins play a significant role in this regard as they enable companies to test various production strategies and assess their environmental impact. for aerospace manufacturers, this means digital twin technology will now enable easy testing of the effects on the cost and sustainability of a certain process or material and production methods. dss vol. 6, no. 2, 2025, pp.112-121 117 fig. 5 application of digital twin technology in aerospace manufacturing 3.2 use of robotics and cobots for efficiency and safety in industry 5.0, cobots are a collaborative system; hence, they work along with human workers. cobots are flexible, and they easily accept complex tasks along with dynamic variation. unlike the traditional robots separated from human workers, the sensors and safety features of the cobots make them work safely in coordination with humans in a task where the oversight or intervention by humans is beneficial. cobots in aerospace manufacturing can support delicate assembly processes and inspections by helping human workers handle intricate components in a safe manner while they are productive. cobots in industry 5.0 are designed to be efficient and have ai capabilities and to be able to learn from human interaction while performing operations according to the optimized results [28]. cobots are generally used to support complex decision-making and to perform tasks requiring cognitive skills. technology in aerospace manufacturing and maintenance: cobots may be used to inspect aeronautical components for wear and tear, assist technicians in inspections, and even perform repairs at locations that are hard to reach or difficult to access. these result in reduced human exposure to hazardous conditions while improving process reliability as a whole [29]. 3.3 artificial intelligence for optimized resource utilization the integration of ai in aerospace manufacturing enables producers to optimize their manufacturing not only materially but also energetically and in time. the system based on ai is capable of real-time analysis of humongous amounts of data, combined with predictive insights that help optimize the resource usage in the production process. in aerospace, precision, quality, and cost control are especially critical, and ai-based solutions go a long way in increasing productivity hand-in-hand with waste reduction. the contribution of ai in aerospace engineering encompasses a number of applications, including the prediction of the wear and tear of the equipment and the maintenance requirements to avoid sudden stoppages and extend the life of the equipment. this will allow aerospace manufacturers to alter the mechanical maintenance approach from reactive to predictive and make use of available resources without any compromises on production schedules. furthermore, ai algorithms could optimize supply chains by better forecasting demand, managing inventory, and reducing material waste within the supply chain. since aerospace-grade materials are so extremely expensive, this is particularly important [30]. moreover, thrust manufacturing is affected by ai, which ascertains its role in quality improvement and resource consumption reduction. applying ai for real-time monitoring of production parameters will help the manufacturer to adjust conditions in an immediate manner, so that utmost efficiency can be achieved in resource usage. for instance, with the application of temperature, pressure, and machining parameters dynamically by ai-enabled systems, the materials would be sure to be processed without excess use, thus making manufacturing processes more sustainable [31]. 3.4 advanced data analytics and predictive maintenance advanced data analytics and predictive maintenance help aerospace manufacturing turn the corner from reactionary management of equipment. big data and machine learning underpin predictive maintenance, which identifies the likelihood of failure and reduces downtime while maintaining longer periods on critical machinery and components. predictive maintenance provides the foundation for aerospace, allowing manufacturers to ensure that certain levels of precision and reliability are achieved while achieving safety, efficiency, and cost dss vol. 6, no. 2, 2025, pp.112-121 118 effectiveness in the process of manufacturing. using data analytics, problems involving imbalanced data; failure events are rare events in the aerospace industry, where equipment has a high quality, it can be efficiently used [32]. advanced methods of data analytics can enable manufacturers to detect subtle patterns of wear or impending failure, even in sparse data sets with just a few examples of failures. this provision ensures timely notification, which helps prevent or minimize stoppages to equipment, therefore allowing smooth production without any unexpected costs from breakdowns of the equipment. big data analysis also supports predictive maintenance through constant monitoring of equipment health and performance. within aerospace manufacturing, this means collecting data from sensors installed on the machine and analyzing real-time metrics using algorithms. predictive maintenance systems can alert operators before minor issues escalate into more significant safety and efficiency concerns by examining trends and anomalies. this capability also permits strategic scheduling of maintenance, thus allowing more reduction in the disruption of operations and optimal resource utilization [33]. predictive maintenance is of great importance in aerospace as it assists manufacturers in strategically managing the maintenance cycle without resorting to reactive repair of equipment. predictive maintenance systems use data sources from various points, such as vibration, temperature, and operational metrics, to develop an all-around view of the health of the equipment in use [34]. the integrated approach leads to informed decision-making and makes the manufacturing process more resilient by removing waste incurred through unnecessary maintenance and minimizing resources used. 4. alignment with sustainable development goals industry 5.0 would support several of the united nations' sustainable development goals by being both technologically advanced and human-centric. major areas of impact are improving decent work, supporting innovative infrastructure, resource efficiency, as well as climate change management. the above encompasses contributions to sustainable global development because of the relevance to most of the sdgs by industry 5.0 [35]. 4.1 sdg 8: decent work and economic growth – impact of industry 5.0 on workforce industry 5.0 approaches are very human-centered since they center the workforce on innovations of advanced manufacturing. emphasis on such aspects would be useful for promoting sdg 8, as it promotes a safer and friendlier workplace along with skill evolution parallel to technology evolution. the combination of cobots and ai at industry 5.0, therefore, eliminates boredom at work and enhances productivity as job satisfaction increases since tasks that are drab or dangerous are left to the machines. changing the paradigm of economic growth, this shift will therefore aim at favoring decent work conditions as found in the world's "endeavor to promote sustained, inclusive economic growth, productive employment, and decent work for all.". 4.2 sdg 9: industry, innovation, and infrastructure – advancements in sustainable production industry 5.0 establishes a resilient infrastructure and promotes inclusive, sustainable industrialization to support sdg 9. it is through such developments with digital twins, predictive maintenance, and smart factories that it delivers more efficient and more agile manufacturing systems. such innovations reduce production downtime, enhance quality control, and lead to better use of resources, and lead towards a more sustainable and resilient industrial landscape. tied to this is connectivity and real-time data sharing, leading to intelligent, agile infrastructure for industry 5.0 in constant improvement and innovation. 4.3 sdg 12: responsible consumption and production – resource efficiency and waste reduction some of the key objectives of industry 5.0 involve better resource efficiency, less waste, and circular approaches in manufacturing, thus directly related to sdg 12. technologies like ai-based predictive analytics will optimize the usage of materials, improve the management of inventories, and cut down energy consumption. furthermore, additive manufacturing would allow for precise, on-demand production, decreasing overproduction and waste. it promotes responsible consumption and production, encouraging efficient use of resources, which reduces the environmental impacts by meeting the demands of modern society. 4.4 sdg 13: climate action – emission reduction and sustainable energy use industry 5.0 supports climate action through energy-efficient technologies and the use of sustainable energy sources, in line with sdg 13. for instance, ai in energy management will optimize the power consumption of manufacturing facilities, while renewable energy will reduce dependence on fossil fuels. smart factories rely on iot and data analytics to monitor and reduce their emissions, thereby supporting low-carbon manufacturing dss vol. 6, no. 2, 2025, pp.112-121 119 ecosystems. all these initiatives mean that industry will have a strategic direction on the reduction of industrial carbon footprint to ensure that impacts of climate change are mitigated for the contribution to global goals. 5. conclusions industry 5.0 is the era of manufacturing revolution, where human-centered innovation, advanced digital integration, and sustainability are central. this paper discusses some of the foundational principles of industry 5.0 toward sustainable manufacturing, with its specific application in the aerospace sector. collaborative technology integration in the form of artificial intelligence, the internet of things, cyber-physical systems, and robotics culminates in a highly productive, safe, and more efficient smart manufacturing ecosystem. industry 5.0 focuses on close human-machine collaboration in order to ensure that the workers are involved in meaningful tasks for effective operational benefits and job satisfaction. in aerospace manufacturing, its implementation through the deployment of smart factories and digital twins contributes to advanced data analytics, predictive maintenance, optimized use of resources, and an increase in the reliability of the product. that leads to a paradigm shift with close alignment to the fundamental sustainable development goals, enabling responsible consumption, inclusive growth, and environmental stewardship. industry 5.0 redefines manufacturing processes and also provides a broader need by society through its commitment towards sustainable growth. industry 5.0 holds the great promise of achieving resilient, sustainable, and inclusive manufacturing ecosystems with a prospect of long-term industrial and economic growth. this paradigm asserts that innovation should be balanced by social and environmental responsibility based on technological prowess. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] a. moldavska, and t.welo, "a holistic approach to corporate sustainability assessment: incorporating sustainable development goals into sustainable manufacturing performance evaluation," journal of 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commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 94 hezbollah and russian intelligence collaboration: a complex nexus anastasios-nikolaos kanellopoulos 1*, 1 department of business administration, athens university of economics and business, greece *corresponding author e-mail: ankanell@aueb.gr received: oct. 20, 2023 revised: nov. 8, 2023 accepted: nov. 9, 2023 online: nov. 13, 2023 abstract this paper delves into the intricate relationship between hezbollah, the shiite militant organization based in lebanon, and russian intelligence agencies (ria). the collaboration between hezbollah and ria represents a complex interplay of geopolitical interests, regional dynamics, and strategic objectives. the paper examines the historical context of their relationship, the motivations behind their cooperation, the nature of their interactions, and the implications for regional and global security. drawing upon a multidisciplinary approach that combines insights from political science, international relations, intelligence studies, and middle eastern studies, provides a comprehensive analysis of this collaboration. it also explores the broader implications for the middle east, russia's role in the region, and the challenges it poses to international efforts to counter terrorism and promote stability. © the author 2023. published by arda. keywords: hezbollah, russian intelligence, iran, israel, south america, africa 1. introduction the collaboration between hezbollah, the shiite militant organization based in lebanon, and ria has emerged as a complex and intriguing aspect of the geopolitical landscape in the middle east. hezbollah, founded in the early 1980s, has evolved into a powerful regional actor with a dual identity as a political party and a militant group. its historical ties to iran and syria have significantly shaped its regional presence and influence [1]. ria, notably the federal security service (fsb) and the main intelligence directorate (gru), have expanded their activities in the middle east, positioning russia as a key player in regional affairs. the collaboration between hezbollah and ria reflects a convergence of interests, primarily centered on counterterrorism efforts and regional stability. this paper seeks to provide a comprehensive analysis of the hezbollah-russia collaboration. it explores the historical context of their relationship, the motivations driving their cooperation, the nature of their interactions, and the implications for regional and global security. it also considers the broader implications for the middle east, russia's role in the region, and the challenges it poses to international efforts to counter terrorism and promote stability. 2. research method the present study is a review article, that serves as an in-depth exploration of the existing body of literature concerning hezbollah, ria, and their collaborative interactions. it underscores the paramount importance of dss vol. 4, 2023, pp.94-104 95 synthesizing a wide spectrum of source materials, encompassing academic studies, government reports, policy documents, and media sources, to facilitate a holistic comprehension of this intricate subject matter. by incorporating academic studies, this review establishes a scholarly foundation for comprehending the historical evolution, ideological underpinnings, and operational intricacies of both hezbollah and ria. the inclusion of government reports and policy documents contributes a policy-oriented perspective, offering insights into the strategic implications and security ramifications of their associations, while also illuminating the responses of relevant state actors. 2.1 hezbollah: the shiite militant organization hezbollah, whose name translates to "party of god" in arabic, is a shiite islamist organization with its roots firmly embedded in the tumultuous history of lebanon and the wider middle east. its journey from a fledgling revolutionary militant group to a dominant political force within lebanon is a tale marked by conflict, resilience, adaptation, and complex regional dynamics. 2.1.1 foundations amid civil strife: 1982-1990 hezbollah's origins can be traced back to the early 1980s when lebanon was embroiled in a protracted civil war and under israeli occupation. this period of intense turmoil provided fertile ground for the emergence of shiite resistance movements, including hezbollah. inspired by the iranian revolution of 1979 and supported by iran's revolutionary ideology, the group was founded in the aftermath of israel's invasion of lebanon in 1982 [2]. initially, hezbollah's primary objective was to resist the israeli occupation and contribute to the expulsion of foreign forces from lebanese territory. drawing from a wellspring of religious fervor, the organization engaged in acts of violence against israeli military targets, garnering both popular support among lebanon's shiite community and condemnation from international actors. the 1983 bombings of the u.s. embassy and marine barracks in beirut, which resulted in significant casualties, highlighted hezbollah's militant tactics and its readiness to employ suicide bombings. 2.1.2 transition to political power: 1990s the early 1990s marked an important, pivotal period in hezbollah's evolution as lebanon attempted to emerge from the ashes of civil conflict. the taif agreement of 1989, which ended the civil war, paved the way for political reforms and power-sharing arrangements. hezbollah, sensing the changing political landscape, embarked on a strategic shift towards becoming a recognized political entity while maintaining its military capabilities [3]. in 1992, hezbollah participated in lebanon's parliamentary elections for the first time, securing a notable presence within the lebanese political system. simultaneously, it continued its resistance efforts against israeli forces in south lebanon, earning admiration as a defender of lebanese sovereignty, especially among the shiite population [4]. 2.1.3 resistance and regional dimensions: 2000s the year 2000 marked a significant victory for hezbollah when it successfully pressured israel to withdraw its troops from south lebanon, claiming it as a victory for the "resistance." this achievement bolstered the group's reputation as a formidable force and established it as a key player in lebanese politics [2]. hezbollah's regional influence also expanded during this period, particularly through its alliance with iran and syria. its involvement in regional conflicts, including the support for syrian president bashar al-assad's regime in the syrian civil war, positioned it as a critical actor in the broader middle east. additionally, the group's military capabilities continued to grow, backed by iranian support and bolstered by its experience in asymmetric warfare [4]. 2.1.4 2006 war with israel: consolidation of power dss vol. 4, 2023, pp.94-104 96 one of the defining moments in hezbollah's history occurred in 2006 when a conflict erupted between the group and israel. sparked by the abduction of israeli soldiers by hezbollah, the war resulted in widespread destruction in lebanon and significant casualties on both sides. despite the devastation, hezbollah claimed a propaganda victory, depicting its resilience and ability to withstand a powerful adversary [2]. this conflict solidified hezbollah's status as a formidable military force and further entrenched its role in lebanese politics. domestically, it capitalized on the war's aftermath, participating in lebanese governments and parliamentary elections. the group's "two-track" strategy, maintaining its military capabilities while engaging in political processes, proved effective in securing both popular support and political influence [5]. 2.1.5 2010s and beyond: regional influence and challenges in the 2010s, hezbollah continued to navigate the intricate web of regional politics, particularly in the context of the syrian civil war. its military intervention in syria in support of the assad regime exposed it to criticism, both regionally and internationally, while also reinforcing its alliance with iran [6]. at the same time, hezbollah's social services and charity networks played a crucial role in providing for lebanon's shiite population, contributing to its popularity and influence within its community. however, this dual identity as a militant group and a provider of social services posed complex challenges and dilemmas for the organization. in recent years, lebanon has experienced a series of political and economic crises, with widespread protests against political corruption and mismanagement. hezbollah, as a significant political force in the country, has faced mounting pressure to address these issues and address the demands of the lebanese people. 2.1.6 hezbollah's ideological foundations hezbollah's ideological foundations are deeply rooted in twelver shiite islam, a branch of islam that holds the belief in twelve divinely appointed imams after the prophet muhammad [2]. the organization's ideology is characterized by several key principles:  wilayat al-faqih: at the core of hezbollah's ideology is the concept of "wilayat al-faqih," which translates to "guardianship of the jurist." this doctrine, propagated by iran's ayatollah ruhollah khomeini, asserts that an islamic jurist (faqih) holds ultimate authority over the state, acting as the spiritual and political guide. hezbollah's adherence to this doctrine aligns it closely with iran's theocratic system.  resistance: central to hezbollah's ideology is the principle of resistance, both against foreign occupation and perceived oppressors. this principle is rooted in the historical experience of shiite communities in lebanon, who faced marginalization and persecution.  anti-israel stance: hezbollah's staunch anti-israel stance is a cornerstone of its ideology. it views the israeli state as an illegitimate occupier of palestinian and lebanese lands, and its armed struggle against israel is justified on religious and nationalistic grounds.  social justice: while primarily known for its military activities, hezbollah also emphasizes social justice and the provision of social services to its constituents, particularly within lebanon's shiite community. this combination of military and social roles sets hezbollah apart as both a militant group and a political party. 2.1.7 hezbollah's strategic objectives hezbollah's objectives have evolved over time, reflecting its dynamic role in lebanese and regional politics [2]. its primary objectives can be summarized as follows:  resistance against israel: hezbollah's foremost objective is the liberation of lebanese territory, specifically the shebaa farms and kfar shuba hills, which it considers occupied by israel. its military dss vol. 4, 2023, pp.94-104 97 wing, the islamic resistance, is dedicated to this cause, and it has engaged in multiple conflicts with israel, including the 2006 war [4].  political influence: hezbollah aims to maintain and expand its political influence within lebanon. it participates in the lebanese government and parliament, where it holds significant power and represents the shiite community.  regional engagement: hezbollah's regional engagement extends to support for allies such as syria's assad regime and close cooperation with iran. its regional objectives include countering sunni extremism and enhancing shiite influence [7].  social services: hezbollah provides an array of social services, including healthcare, education, and financial assistance, primarily to lebanon's shiite population. these services contribute to its popularity and maintain a social welfare infrastructure. 2.1.8 hezbollah's organizational structure hezbollah's organizational structure is a meticulously designed system that reflects its dual identity as a militant organization and a political party within lebanon. this intricate structure enables hezbollah to exert influence across multiple domains, both domestically and regionally. at its helm is the secretary-general, currently hassan nasrallah, who wields significant authority and serves as the organization's primary spokesperson. beneath this top leadership tier is the shura council, a high-level decision-making body responsible for strategic planning and oversight [8]. hezbollah's executive council manages its daily operations and oversees specialized committees, each dedicated to distinct functions such as military operations, political engagement, and social services. the military wing, known as the islamic resistance, is central to hezbollah's identity and serves as its armed force. highly trained and well-armed, the islamic resistance is responsible for conducting cross-border attacks against israel and safeguarding the organization's military capabilities. the political wing of hezbollah operates within lebanon's formal political institutions, with elected representatives in parliament and cabinet members in the government. this political presence grants hezbollah significant influence in lebanese politics, particularly within the shiite community, and allows it to shape policies and decisions [9]. hezbollah's social services sector is equally vital; it operates an extensive network of hospitals, schools, and charities that provide essential support to lebanon's shiite population. this multifaceted approach, combining military might with social welfare initiatives, enhances hezbollah's support base and bolsters its legitimacy [10]. hezbollah also maintains a sophisticated media and propaganda apparatus that disseminates its messages and activities through various channels, including television, radio, and social media. this media wing plays a crucial role in shaping public perception and maintaining cohesion among its supporters. overall, hezbollah's organizational structure is characterized by hierarchical leadership, tight internal cohesion, and a wellbalanced integration of political, military, and social elements. this dynamic structure enables hezbollah to exert influence on both domestic and regional fronts, contributing to its enduring prominence in the complex geopolitics of the middle east. understanding this intricate organizational design is essential for comprehending the organization's multifaceted role and its impact on lebanon's political landscape and regional dynamics [11]. 2.2 russian intelligence: a strategic apparatus 2.2.1 overview of russian intelligence agencies the russian federation boasts a formidable and complex array of intelligence agencies that play pivotal roles in shaping domestic and international affairs. these agencies are renowned for their operational prowess and dss vol. 4, 2023, pp.94-104 98 the extent of their reach, reflecting russia's longstanding commitment to intelligence gathering, espionage, and covert operations. while several intelligence agencies operate within russia, some of the most prominent ones include the federal security service (fsb), the main intelligence directorate (gru), and the foreign intelligence service (svr). federal security service (fsb): the fsb is russia's primary domestic intelligence agency, responsible for a wide range of security functions within the country. its mandate includes counterterrorism, counterintelligence, cyber defense, border security, and monitoring political dissent. the fsb's influence extends to domestic surveillance and intelligence gathering, making it a powerful entity in domestic politics and national security. it is worth noting that the fsb's roots can be traced back to the kgb, the soviet-era intelligence agency, which was disbanded after the collapse of the soviet union [12]. main intelligence directorate (gru): the gru is russia's military intelligence agency and is renowned for its clandestine operations, espionage, and special forces capabilities. unlike the fsb and the svr, which focus on domestic and foreign intelligence respectively, the gru primarily serves the russian armed forces [13]. its missions encompass gathering military intelligence, conducting covert operations, and supporting russian military activities worldwide. the gru has earned notoriety for its alleged involvement in cyberattacks, disinformation campaigns, and efforts to undermine foreign governments, making it a focal point of international scrutiny [14]. foreign intelligence service (svr): the svr is russia's primary foreign intelligence agency and specializes in collecting intelligence from abroad. its primary mission is to gather information on foreign governments, organizations, and individuals, as well as to engage in covert operations to further russian interests internationally. the svr plays a crucial role in russia's foreign policy, providing decision-makers with critical intelligence assessments and supporting diplomatic efforts. while its operations are generally more discreet compared to the gru, the svr has faced allegations of interference in foreign elections and espionage activities on multiple occasions. these intelligence agencies are part of a broader intelligence community in russia, which also includes specialized agencies such as the federal protective service (fso) responsible for protecting high-ranking officials, and the federal drug control service (fskn) involved in combating drug trafficking. additionally, russia's intelligence agencies often work in coordination with each other and have well-established ties to the kremlin, allowing for effective information-sharing and policy alignment [15]. the ria community's capabilities and activities have drawn significant international attention and concern, particularly in the context of allegations of election interference, cyberattacks, and espionage operations. understanding the roles and functions of these intelligence agencies is crucial for comprehending russia's approach to national security and its broader geopolitical strategies on the global stage. 2.2.2 russian intelligence regional presence, collaborations, and strategy ria, renowned for its clandestine prowess and historical significance, maintains a robust regional presence and engages in strategic collaborations across the globe. these agencies, deploy their expertise to protect russia's national interests, project power, and influence geopolitical outcomes. their regional focus extends from neighboring states to far-flung regions, encompassing europe, the middle east, asia, and beyond. their strategic collaborations are designed to counter adversaries and bolster moscow's standing in an increasingly complex and competitive world [16]. in the european theater, ria has a long-standing history of involvement in espionage activities. the svr, responsible for foreign intelligence, maintains an extensive network of agents and assets across europe. it closely monitors the activities of nato, the european union, and individual member states, seeking to gain insights into their decision-making processes and policy directions. this information is vital for russia's strategic planning and diplomatic maneuvering. additionally, the gru, with its specialization in military dss vol. 4, 2023, pp.94-104 99 intelligence, has a strong presence in europe, particularly concerning the baltic states, ukraine, and the balkans. the gru plays a crucial role in supporting pro-russian separatist movements and conducting cyber operations, as demonstrated in ukraine. moving eastward, ria have intensified their efforts in the middle east and north africa. this region holds immense significance due to its vast energy reserves and its role as a battleground for regional and global powers. the svr and the fsb, in coordination with the russian ministry of defense, have established close ties with the syrian government, providing military support and intelligence assistance to president bashar alassad's regime. this has allowed russia to maintain a strategic foothold in the middle east and expand its influence across the region. furthermore, ria collaborate with iran and support proxy groups in yemen, enhancing their ability to shape events in this volatile region. in asia, russia's intelligence agencies focus on strengthening ties with countries that share its vision of a multipolar world order. the russian government, led by president vladimir putin, seeks to counterbalance western influence in the region by collaborating with china, india, and central asian states. the svr and the fsb work closely with their counterparts in these countries to exchange intelligence, counter terrorism, and combat cyber threats. this strategic collaboration not only advances russian interests but also challenges the dominance of western intelligence agencies in the region. beyond regional presence and collaborations, ria employ a multifaceted strategy that combines traditional espionage, cyber operations, and disinformation campaigns to achieve their objectives. one notable example is russia's interference in the 2016 united states presidential election, which brought the extent of its capabilities into the global spotlight. the gru's cyber unit, known as apt28 or fancy bear, allegedly hacked the democratic national committee's emails, revealing sensitive information that influenced the election narrative. this operation showcased russia's proficiency in hybrid warfare, blending cyberattacks with information warfare to disrupt and shape political landscapes. in addition to cyber operations, disinformation campaigns orchestrated by ria have become a potent tool in influencing public opinion and destabilizing adversaries. the internet research agency (ira), a kremlinlinked troll farm, is notorious for its efforts to spread disinformation and sow discord on social media platforms during the 2016 u.s. election and other events worldwide. such activities not only create confusion but also exploit existing fault lines within target societies, amplifying divisions and weakening the social fabric of rival nations. furthermore, ria employ a tactic known as "active measures" to manipulate foreign governments and organizations covertly. these measures involve the use of espionage, covert influence, and propaganda to advance russia's interests while obscuring its involvement. for example, the svr's "illegals" program, exposed in 2010, revealed a network of deep-cover spies living under false identities in the united states and other western countries. these operatives conducted espionage activities and gathered sensitive information, all while maintaining the facade of ordinary citizens [12]. 2.3 the historical context of hezbollah and russian intelligence collaboration the collaboration between hezbollah, the lebanon-based shiite militant group, and ria is a complex and multifaceted relationship that has evolved over several decades. to understand this collaboration, it is crucial to delve into the historical context that has shaped their interactions. hezbollah's origins trace back to the chaotic and turbulent landscape of lebanon in the 1980s. this period was marked by a protracted civil war, israeli occupation of southern lebanon, and the presence of various sectarian militias vying for control. in this milieu, hezbollah emerged as a shiite resistance movement with strong ideological ties to iran's theocratic regime. iran, eager to establish a shiite bulwark against israel and promote its revolutionary ideals, became a key patron of hezbollah, providing it with financial, military, and ideological support [17]. dss vol. 4, 2023, pp.94-104 100 at the same time, the soviet union was in the midst of its twilight years, with the cold war era winding down. the dissolution of the soviet union in 1991 saw the emergence of the russian federation under the leadership of boris yeltsin. during this period, ria, including the federal security service (fsb) and the main intelligence directorate of the general staff of the armed forces (gru), underwent significant transformations. they sought to adapt to a new global order characterized by multipolarity and an evolving security landscape. the historical context of the collaboration between hezbollah and ria begins to take shape in the late 1990s and early 2000s. this period witnessed a series of events that laid the foundation for their interaction. first, hezbollah consolidated its position in lebanon, transforming from a guerrilla group into a political and military force with significant influence in lebanese politics. second, russia, under vladimir putin's leadership, embarked on a more assertive foreign policy agenda, seeking to regain its status as a major global player. as part of this strategy, russia aimed to strengthen its presence in the middle east, a region where it had historical ties dating back to the soviet era [18]. one critical turning point in the hezbollah-russia relationship was russia's involvement in the syrian conflict, which began in 2015. hezbollah had long maintained close ties with the syrian regime of bashar alassad, viewing it as a crucial ally in the region. when russia intervened militarily to support assad, it created a common strategic interest between moscow and hezbollah: the preservation of the syrian regime and the containment of islamist extremist groups, including isis. this shared goal became the catalyst for deeper collaboration [19]. ria, notably the gru, found themselves working alongside hezbollah in syria. while their immediate objectives aligned in syria, the collaboration also extended to intelligence-sharing and coordination. hezbollah's expertise in the region, including its knowledge of local actors and terrain, complemented russia's military operations. ria benefited from hezbollah's human intelligence assets and local networks, which provided valuable insights into the evolving dynamics of the syrian conflict. another dimension of their collaboration emerged in the realm of counterterrorism. both hezbollah and russia faced threats from islamist extremist groups operating in syria and the broader middle east. hezbollah had extensive experience in combating groups like al-qaeda and its affiliates. ria sought to harness this expertise in their efforts to neutralize terrorist threats, both regionally and globally. their cooperation included sharing information on extremist networks, intelligence analysis, and joint operations [20]. furthermore, the collaboration between hezbollah and ria took on a covert dimension, particularly in the realm of arms transfers and logistics. reports suggest that hezbollah may have received weapons and support from russian sources, facilitated through clandestine channels. while the exact extent and nature of this covert collaboration remain shrouded in secrecy, it underscores the multifaceted nature of their relationship. 3. results and discussion 3.1. the potential of collaboration in south america the potential collaboration between hezbollah and ria in south america is a matter of concern and speculation within the international intelligence community. while there is no concrete evidence to suggest a direct and formal alliance between these two entities in the region, it is essential to analyze the factors that could influence such collaboration, as well as the potential implications for south america's security and geopolitical landscape [3]. first and foremost, it is crucial to understand the motives that might drive hezbollah and ria to explore cooperation in south america. hezbollah, known for its global reach and willingness to form alliances with sympathetic actors, has a history of establishing networks beyond the middle east. south america has a significant shiite lebanese diaspora, which offers hezbollah a potential source of financial support and dss vol. 4, 2023, pp.94-104 101 recruits. moreover, the region's porous borders and weak governance structures could provide fertile ground for hezbollah's fundraising and logistical activities, particularly in the illicit drug trade. russia, on the other hand, has been seeking to expand its influence in various regions, including south america, as part of its efforts to counterbalance western dominance. collaborating with hezbollah could allow russia to gain leverage in a region traditionally considered within the sphere of influence of the united states [21]. one area where collaboration between hezbollah and ria could manifest is in the realm of cyber warfare. both entities have demonstrated their capabilities in the cyber domain. hezbollah, with support from its iranian sponsors, has engaged in cyber activities, including hacking and disinformation campaigns. ria, such as the gru, have been accused of orchestrating cyberattacks in various parts of the world. in south america, these two entities could share expertise and resources, potentially targeting critical infrastructure, government institutions, or financial systems. such cyber collaboration could have significant destabilizing effects and pose a threat to regional cybersecurity. another aspect to consider is the potential convergence of interests in the illicit economy. south america has long been a hub for drug trafficking, with various criminal organizations operating in the region. hezbollah has been accused of involvement in the drug trade to finance its activities, and russia has a history of exploiting illicit networks to advance its interests. collaboration in this arena could involve intelligence sharing, money laundering, or even joint operations to protect drug routes and maximize profits. such collaboration could undermine the rule of law and fuel criminal enterprises, further destabilizing the region [22]. additionally, the political landscape in south america presents opportunities for hezbollah and ria to collaborate. some countries in the region have experienced political instability and anti-western sentiments, creating an environment in which these actors may find common cause. russia has sought to build alliances with governments that are critical of the united states, and hezbollah has used political influence to gain support among shiite communities and sympathetic political factions. the convergence of their interests could lead to cooperation in influencing domestic politics, shaping policy decisions, or even supporting like-minded political movements [17]. 3.2 the potential of collaboration in africa the potential collaboration between hezbollah, the lebanese shiite militant group, and ria in africa is a topic that raises concerns and speculation among experts and policymakers. while there is no concrete evidence to confirm a direct and formal alliance between these two entities on the african continent, it is essential to explore the factors that could influence such collaboration and consider the potential implications for africa's security, geopolitics, and regional stability [3]. one of the factors that could drive hezbollah and ria to explore collaboration in africa is the region's increasing strategic importance. africa's vast resources, including minerals, energy reserves, and agricultural lands, have attracted the interest of global powers seeking to secure their access to these valuable assets. russia, under president vladimir putin's leadership, has been eager to expand its influence in africa as part of its broader strategy to counterbalance western dominance. hezbollah, with its global reach and connections, may see opportunities to align with russian interests on the continent [23]. additionally, both hezbollah and ria have demonstrated their capabilities in the realms of unconventional warfare and asymmetric tactics. hezbollah, with support from iran, has honed its skills in guerrilla warfare, terrorism, and proxy conflicts in the middle east. russia, through its intelligence agencies like the gru, has engaged in hybrid warfare tactics, including disinformation campaigns, cyberattacks, and support for paramilitary groups. these shared expertise areas could provide a basis for collaboration, as both entities seek to leverage their skills in a region characterized by conflicts, instability, and weak governance. dss vol. 4, 2023, pp.94-104 102 one area where collaboration might manifest is in the field of intelligence sharing and analysis. ria, with their extensive global reach, could provide hezbollah with valuable information on african governments, regional dynamics, and emerging security threats. this intelligence could assist hezbollah in identifying potential partners, allies, or opportunities for expanding its influence on the continent. in return, hezbollah's networks and expertise could support ria efforts to gather information, track extremist groups, and protect its interests in africa [24]. the evolving security landscape in africa also presents potential opportunities for collaboration. the continent faces a range of security challenges, including terrorism, organized crime, and insurgency movements. hezbollah has experience in asymmetric warfare and has been accused of providing training and support to various militant groups in the middle east. ria, likewise, have engaged in counterterrorism operations and have supported governments in conflict zones. their collaboration could involve coordinating efforts to combat common threats, such as islamist extremist groups operating in africa, thereby enhancing regional security. moreover, africa's political terrain, marked by diverse governments, shifting alliances, and fragile states, offers opportunities for hezbollah and ria to exert influence. both entities have a history of manipulating political processes and supporting like-minded factions. hezbollah has sought to gain political influence in lebanon and beyond, while russia has pursued strategic partnerships with governments that align with its interests. in africa, their collaboration might involve supporting sympathetic political actors or influencing political outcomes to advance their shared goals. 4. conclusions in conclusion, the examination of the potential collaboration between hezbollah and ria reveals a complex and multifaceted nexus that exists within a rapidly changing global landscape. while there is no definitive evidence to confirm a direct and formal alliance between these two entities, various factors suggest that their interests may converge in regions of strategic importance, such as the middle east, south america, and africa. hezbollah's global reach, expertise in asymmetric warfare, and connections to iran provide it with a unique set of capabilities and interests, while russia, under president vladimir putin's leadership, seeks to expand its influence and counterbalance western dominance on the international stage. the potential areas of collaboration span from intelligence-sharing and analysis to cyber warfare, asymmetric tactics, and influence operations. both entities have demonstrated their capabilities in these domains and may find opportunities to align their interests in regions where conflicts, instability, and weak governance prevail. however, numerous obstacles and risks, including the presence of western intelligence agencies, local dynamics, and potential backlash, could deter or limit the extent of their collaboration. the implications of such collaboration, if it were to materialize, would extend beyond the regions of interest to impact global security, stability, and the balance of power. it would raise concerns about the potential exacerbation of conflicts, destabilization of regions, and threats to cybersecurity. as such, international stakeholders, including governments, regional organizations, and intelligence agencies, must remain vigilant and proactive in monitoring, analyzing, and countering any activities that may pose a threat to peace and security. in an era marked by increasing uncertainty, shifting alliances, and emerging security challenges, understanding and addressing the potential collaboration between non-state actors like hezbollah and state actors like russia is essential. this complex nexus underscores the evolving nature of international relations, where traditional and non-traditional actors alike seek to advance their interests in an interconnected and rapidly changing world. it is incumbent upon the global community to adapt and respond effectively to these dynamics, prioritizing diplomacy, conflict prevention, and the protection of international norms and values to maintain global stability and security. dss vol. 4, 2023, pp.94-104 103 declaration of competing interest the author declares that has no known financial or non-financial competing interests in 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[21] s. kelly, “hezbollah is operating in latin america. what does that mean for the u.s.?,” the cipher brief, https://www.thecipherbrief.com/hezbollah-is-operating-in-latin-america-what-does-that-mean-forthe-us (accessed oct. 20, 2023). [22] “hezbollah in latin america implications for u.s. homeland security,” u.s. government publishing office, https://www.govinfo.gov/content/pkg/chrg-112hhrg72255/html/chrg-112hhrg72255.htm (accessed oct. 20, 2023). [23] a. toulu, “the iranian revolutionary apparatus and hezbollah in west africa,” hudson, https://www.hudson.org/node/44280 (accessed oct. 20, 2023). [24] “hezbollah strategic shift: a global terrorist threat,” u.s. government publishing office, https://www.govinfo.gov/content/pkg/chrg-113hhrg80122/html/chrg-113hhrg80122.htm (accessed oct. 20, 2023). microsoft word 91-102_285 (online) issn 2744-1741 defense and security studies original research vol. 6, no. 1, 2025, pp.91-102 https://doi.org/10.37868/dss.v6.id285 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 91 the evolution of warfare from conventional to a digital battlefield: an analysis of cyber technology and artificial intelligence in the lebaneseisrael conflicts sereina khalifeh1* 1 political science and international relations, lebanese american university, lebanon *corresponding author e-mail: sereinakhalifeh@outlook.com received: may 8, 2025 revised: jun. 1, 2025 accepted: jun. 7, 2025 online: jun. 9, 2025 abstract this study will evaluate the transition from conventional combat methods to a technology-driven battlefield. in particular, the lebanon-israel conflict serves a crucial case study to analyze how digital tools and ai reshape battlefield strategies, operational efficiency, and psychological warfare, triggering a broader evolution in modern military doctrine. this study will tackle a longitudinal comparison of digital strategy evolution in a single dyadic conflict zone. it adds to fields of security studies, cyberwarfare strategy, and ai-driven conflict analysis by analyzing how asymmetric technological adoption constructs long-term power dynamics. through a theoretical lens of realism and a complementary military geopolitical framework, this research will analyze the impact of cyber warfare, aidriven decision-making, intelligence, and precision missile systems on military strategies, political decision-making, and regional security. © the author 2025. published by arda. keywords: cyber-warfare, artificial intelligence, lebanon-israel conflicts, military strategy, technology warfare, hybrid warfare, middle east security 1. introduction the warfare has gone through a significant transition, shifting from conventional combat methods to a technology-driven battlefield. historically, wars have been fought through direct confrontation, depending on infantry, armored vehicles, and aerial bombardments. however, with the development of military technology, modern warfare has incorporated cyber operations, ai, and precision-guided weapons. this advancement has altered military strategies and significantly impacted war outcomes, reconstructing battlefield dynamics, decision-making processes, and geopolitical power structures. the middle east, a central region for persistent conflicts and shifting military strategies, presents an important case for analyzing such shifts. in particular, the lebanon-israel conflict serves as a crucial case study to analyze the transition from conventional to technology-advanced warfare. through the evaluation of the role of cyber technology and artificial intelligence (ai) in the lebanon-israel conflict of 2006 and 2023-2024. through a theoretical lens of realism and a complementary military geopolitical framework, this research will analyze the impact of cyber warfare, ai driven decision-making, intelligence, precision missile systems on military dss vol. 6, no. 1, 2025, pp.91-102 92 strategies, political decision-making, and regional security. this research study will evaluate how technological advancements have redefined the nature of modern military engagements and changed the outcomes of wars within the middle east. thus, this research seeks to answer the question of how ai and cyber warfare affected the strategic calculus and balance of power between israel and hezbollah from 2006 to 2024. 2. literature review the transition from conventional combat to a technology-driven battlefield has redefined military strategies and reconstructed geopolitical dynamics. the introduction of ai-driven military technologies and cyber warfare has altered military engagements in the middle east. according to kallenborn [6] and the marine corps association [9], ai has altered decision-making intelligence into modern military strategies and facilitated the dependence on cyber operations and precision-guided weapons. to illustrate, ai has become a centralized tool in target acquisition, predictive analytics, battlefield surveillance, and military operations. according to daily sabah [3], both state and non-state actors tend to leverage technology to manipulate adversaries and gain a strategic advantage. for instance, cyber warfare has become an essential element within military operations, where it has a crucial impact on communication networks and intelligence gathering. as this paper delves into a case study of the 2023-2024 lebanon-israel conflict, it shows a rapid evolution of warfare where cyber abilities and ai-driven military systems played a central role within the war. unlike the 2006 war where hezbollah employed an asymmetric war and employed a guerrilla tactic.[2] in the 2023-2024 war, it was evident that a transition to cyberwarfare had been launched. to illustrate, ai-guided missile systems and aiai-assisted command and control have been utilized to disable communication networks, disrupt enemy defenses, and conduct psychological operations [21]. the digital warfare tactics employed by israel had a severe impact on lebanese civilians as beyond the immediate danger of exploding communication devices, these strategies weakened hezbollah as a party and created fear within the country (khalifeh 2024). the psychological impact of such a tactic disrupted everyday life and contributed to a greater terror since anyone can be the victim of such explosions, whether they are affiliated or not. furthermore, israel has taken an innovative approach to ai in its conflict with hezbollah, where it diverted from traditional targeting methods [2]. for example, israel combined human decision-making alongside ai capabilities to maximize operational efficiency. according to barazy [1], the conflict between lebanon and israel extended beyond modern military confrontation and extended into the digital realm, where platforms such as whatsapp and instagram were used to spread false information and share military strategies, such as locations that will be bombed in a specified time. to further explain, both parties have engaged in cyberattacks, account hacking, and misinformation ai campaigns to destabilize each other’s digital infrastructure and manipulate the international opinion [1]. this literature review underscores the importance of understanding the intersection of technology and warfare, especially within the middle east. the integration of such technology can maneuver outcomes and create challenges for weaker parties, redefining global security. 3. methodology this study will employ a mixed-methods approach, combining both qualitative and quantitative research methodologies. through integrating diverse data sources and analytical frameworks, the research seeks to provide a comprehensive examination of the transition from conventional warfare to technology-driven battlefield while focusing on the impact of technology on the outcome of the lebanon-israel conflicts of 2006 and 2023-2024. the study will incorporate both primary sources, such as military reports, government statements, and expert interviews, where it will gather first-hand data on military strategies and technological applications. as well as secondary sources such as academic articles, media coverage, and policy analyses, which will provide contextual and historical insight into the evolution of modern warfare. additionally, this study will employ a strategic approach to analyze the transition from conventional warfare to a technology-driven battlefield, specifically exploring the impact of technology on war outcomes. realism: the primary theoretical lens of the research will analyze the evolution of military strategies, technological integration, and information warfare, emphasizing state behavior, power dynamics, and security competition. furthermore, a case study methodology will be applied to evaluate the impact of ai and dss vol. 6, no. 1, 2025, pp.91-102 93 technological advancements in the lebanon-israel wars in 2006 and 2023-2024. by focusing on this case study, the study will highlight patterns, strategic shifts, and the role of emerging military technologies in determining outcomes of wars. the study justifies its methodology by integrating both primary and secondary accounts, ensuring a balanced assessment of the evolution of modern warfare. by systematically examining available tools, data, and research frameworks, the study aligns its objectives to provide a detailed analysis of shifting warfare trends and the way technological advancements have shaped military successes or failures. moreover, the research is highly feasible since it tackles a modern time conflict that destabilizes the mena region and the central case study is manageable since it is within two specific time frames july 12, 2006, till august 14, 2006) and (october 8, 2023, till november 17, 2024) [26], and it relies on well documented events and assessable scholarly sources. the focus is on the existing conflicts, and it ensures that data availability will not pose a barrier. moreover, by leveraging existing analytical frameworks in conflict studies, the study can provide meaningful insight within a structured timeline. given the volatile nature of cyberwarfare reporting, this study will tackle the triangulation methods. an open-source intelligence is cross-verified with credible think tanks and defense institutes such as nato, csis, cyber readiness reports, and iiss strategic briefing assures data reliability. misinformation risk can be monitored through proper dependency on verified military communiques, academic sources, and media triangulation. the study is grounded on the basis of a realist theoretical lens, especially neorealism (waltz 1979), which highlights the anarchic structure of international systems and the ways ai and cyber warfare have redefined power competition. hybrid warfare [16] will be integrated to showcase a mix of conventional, psychological tactics. to illustrate, the cyber deterrence theory [22] will be emphasized to examine the escalation dynamics and retaliatory calculations surrounding cyber operations. these frameworks will collectively provide insight into how technological advancement has transitioned not only the battlefield but also has affected structural dynamics of power competition within the region. according to neorealism (waltz 1979), the international system is anarchic, and it is driven by a sense of survival through the accumulation of relative power. within this context, israel has invested in ai and cyber warfare capabilities to showcase a strategic response in the evolving nature of threats, especially those posed by non-state actors such as hezbollah. technological dominance has become a form of structural power within the anarchic system, where military superiority ensures deterrence and regional influence. neorealism facilitates israel’s proactive cyber strategy to balance regional power and deter iran-backed asymmetric threats. hybrid warfare theory [16] is important to highlight hezbollah’s military adaptation. hybrid warfare is the blending of conventional warfare, irregular tactics, cyber operations, and psychological campaigns. hezbollah as. anon state actor has combined guerrilla warfare, social media misinformation, cyber destruction, and encrypted communication to counter israel’s technological advantages. this approach showcases the stretch of the battlefield beyond physical terrains into digital and psychological domains, maximizing the effectiveness of limited sources. whereas the cyber deterrence theory [22] provides a different layer of interpretation, where the logic of escalation and retaliation in digital warfare is considered. during the 2023-2024 conflict, the cyberattacks were utilized to disable infrastructure, disrupt financial systems, and demoralize enemy forces without engaging in full-scale kinetic warfare. the theory tends to underscore the strategic ambiguity and asymmetric potential of cyber warfare where attribution is challenging, and retaliation can be calibrated it avoid traditional escalation. this model tends to suit both state actors, such as israel, who aim for precise strikes with minimal fallout, and non-state actors such as israel who aim towards precise and minimal fallout, and non-actors such as “hezbollah” that aim towards benefiting from anonymity and unpredictability within the cyber domain. combined, all these theoretical perspectives tend to offer a multi-layered understanding of lebanon-israel conflicts. realism and neorealism target the broader strategic motivation of different state actors, where hybrid warfare theory illuminates the developing tactics of asymmetric military groups such a hezbollah, and cyber deterrence theory contextualizes the operational logic behind the non-kinetic forms of engagement. this showcases that rage technology is not a tool but a determinant of contemporary military strategy and geopolitical behavior. dss vol. 6, no. 1, 2025, pp.91-102 94 4. comparative analytical framework to evaluate the shift between the lebanon-israel conflict of 2006 and 2023-2024, a comparative matrix was developed alongside four critical dimensions (table 1). table 1. comparative matrix with four critical dimensions dimension 2006 war 2023-2024 war weapons systems conventional artillery, airstrikes, and guerrilla tactics ai-guided missile systems, autonomous drones, cyberattacks communication strategies radio transmissions, satellite phones, centralized media encrypted messaging apps, cyber-infiltration, and decentralized misinformation psychological operations traditional media propaganda (tv, newspapers) ai-generated misinformation, deepfake videos, and real-time digital manipulation civilian impacts physical destruction (infrastructure bombing) digital infrastructure targeting (banking systems, health networks), psychological destabilization via social media 4.1. the evolution of military technology and strategic doctrine the advancement of military technology has transformed the warfare arena, transitioning from traditional methods that rely on conventional weapons and large-scale troop deployments to a technology-driven battlefield dominated by cyber warfare and ai [2]. throughout history, technological advancements have served as a central trigger for military superiority, enabling states to exert their power and maintain security in an increasingly competitive international system (chin 2019). the development of military technology showcases that a state seeks relative gains in power to maintain dominance and counterbalance rivals (waltz 1979). the evolution of military technology can be classified into different stages. early warfare relied on direct combat strategies, with heavy use of infantry, cavalry, and siege warfare. the industrialized revolution had evolved mechanized warfare, such as tanks, aircraft, and long-range artillery, which altered battlefield dynamics. with modernization and globalization, military operations have expanded to include cyberattacks, ai-assisted reconnaissance, and precision-guided weaponry, demonstrating a shift from physical confrontation to strategic technological dominance [3]. moreover, cyber warfare has emerged as a dominant asset within modern conflict as it has reconstructed traditional military engagement. it became an essential element for state actors providing the capability to disrupt the enemy infrastructure, shape geopolitical strategies without any direct military confrontation, and win intelligence advantages (khalifeh 2024). unlike conventional warfare, cyber warfare allows states to exert power asymmetrically through digital systems to weaken adversaries without threatening any conventional military engagement (marine corps association 2023). the reliance on cyber capabilities showcases the transition from traditional kinetic warfare to a more network centric warfare where success is often measured by a sense of ability to control and defend information systems [6] cyber warfare tactics include electronic espionage, sabotage of critical infrastructure, and digital propaganda reflecting its impact on military operations [4]. digital information warfare has evolved into a strategic tool to influence conflicts. states tend to manipulate information to have a sense of control over narratives and weaken the image of their adversary within the public discourse [5]. platforms such as whatsapp and instagram have been weaponized to spread false information and create psychological fear within the public [15]. the evolution of psychological operations showcases the reality of power dynamics where controlling information flow is as important as controlling physical territories. this has extended to the extent where the government and military forces are using ai to influence campaigns and international responses, mobilize public support, and delegitimize enemy morale [7]. as a result, information dominance is interconnected with military strength in modern conflicts [18]. additionally, hybrid warfare integrates cyber, conventional, and information warfare into a single strategic framework that works on state power and reduces vulnerabilities [21]. this integration is crucial for evolution as it maximizes a state’s security while minimizing any military cost and casualties (waltz 1979). the effectiveness of hybrid warfare is dictated by its ability to blur lines between state and non-state actors through utilizing cyber capabilities, misinformation, and unconventional tactics to undermine opponents [2]. states tend to deploy ai-driven drones, automated warfare technologies, and cyber dss vol. 6, no. 1, 2025, pp.91-102 95 infiltration tactics that enhance strategic advantages [3]. this evolution reflects the priority of adapting military doctrine to maintain the relative power in the evolving international system. digital warfare has extended beyond just a battlefield but integrated itself into global politics, where technological evolution in warfare has become a significant influence in regional balances, alliances, and international conflict resolutions. technological dominance has become an asset for securing military and economic power in an anarchic international system (mearsheimer 2001). states must adapt to emerging technologies as a need to maintain their relative power and deter any threats. in this context, digital warfare has redefined the balance of power, it shifted geopolitical strategies, and influenced diplomatic relations [3]. states tend to invest their resources in cybersecurity, ai-driven defense systems, and automated military capabilities, reinforcing their strategic importance within modern warfare [6]. to delve into this notion deeper, as automation in warfare increases, concerns about reduction in human oversight, unintended escalations, and algorithmic errors present new security and ethical dilemmas [4]. to illustrate, as states begin to develop advanced cyber capabilities to enhance their security, adversaries perceive this as a threat, which drives them to increase their own ai warfare investment, and it becomes a competition within the international arena. this creates an escalatory cycle like the nuclear deterrence that took place within the middle east in 2003, yet now it's manifested within cyber arms races and ai-driven military strategies [11]. therefore, the increased reliance on digital warfare as a tool of power projection can become an asset for security and strategic advantage in an anarchic world. as digital warfare remains shaping global power structures, alliances, and conflict dynamics, states need to balance strategic advantage with ethical responsibility, ensuring technological superiority does not cause destabilization or any unintended escalation within future conflicts. 4.2. technological transformation of armed conflict: lebanonisrael (2006-2024) war is an inevitable consequence of power struggles, national interest, and the anarchic nature of international systems (waltz 1979). the lebanon-israel conflicts of 2006 and 2023-2024 exemplify military strength, geopolitical competition, and technological superiority that shape war outcomes. these conflicts were rooted in history and shaped through regional power struggles, driven by security dilemmas. each side of the conflict had sought to deter future threats through escalating military capabilities [16]. these wars have highlighted the changing nature of warfare, where in 2006 war relied mainly on conventional tactics such as the guerrilla tactic used by hezbollah against israel, while in 2023-2024 war introduced cyber warfare, ai, and precision military operations, which altered battlefield strategies [6]. the 2006 war was triggered by a hezbollah cross-border raid on july 12, 2006, during which two israeli soldiers were captured [2]. in response, israel launched a full-scale military operation on lebanon targeting hezbollah positions, lebanese infrastructure, and key military sites in the south. the war lasted around 34 days, causing extreme destruction in lebanon and significant losses. the conflict ended with a united nations-brokered ceasefire (1701 resolution), which called upon the withdrawal of israeli forces and the deployment of lebanese and un peacekeepers along the border [22]. while the 2006 war was fought mainly using conventional combat strategies, the 2023-2024 war between lebanon and israel can be understood as the continuation of a power competition where military strength and technological superiority dictate outcomes. both wars highlighted a sense of a security dilemma where israel and hezbollah (supported by iran) engaged in military escalation to deter future threats. the lebanon-israel conflicts of 2023-2024 were shaped by deep-rooted geopolitical tension, historical animosities, and shifting regional power dynamics [3]. the war in 2023-2024 marked a technological and strategic evolution from previous wars. unlike 2006, this war was infested with cyber warfare, artificial intelligence, and precision military operations. the introduction of ai-assisted battlefield strategies allowed faster response times, predictive analytics for military operations, and enhanced target acquisition [9] the shift from conventional war to technology driven warfare in 2023-2024 war it demonstrates a future conflict that will not be dealt with through physical battlefield but also in cyberspace and digital information domains, making technology superiority a critical factor within military dominance. the integration of ai within military operations has revolutionized modern warfare, where it has enhanced battlefield decision-making, surveillance capabilities, and precision targeting [6]. the lebanon-israel conflict of 2006 and 2023-2024 is a case study of how technological advancements have shifted military strategies. in 2006, the guerrilla warfare and decentralized command provided hezbollah with a strategic edge. for instance, israel dependency on the conventional doctrine and airpower demonstrated key limitations. in 2023 -2024, israel dss vol. 6, no. 1, 2025, pp.91-102 96 employed ai-powered missile guidance, cyber operations, and drone warfare to disable hezbollah’s communication and logistics. hezbollah has adapted by employing encrypted messaging, cyber defenses, and ai-assisted drone swarms, which shows the growing sophistication of non-state actors 4.3. the weaponization of information and infrastructure: the strategic transition in digital warfare ai had minimal to no presence in the lebanese-israeli war. military operations conducted on human intelligence, traditional surveillance, and manual decision making were utilized. conventional artillery and piloted airstrikes were employed with no automation or predictive analysis. for instance, the lack of automated systems translated into slower military decision-making, causing it to be slow and heavily reliant on human interpretation of battlefield conditions [13]. while israel airstrikes targeted hezbollah’s positions and hezbollah eventually launched missile barrages into israeli cities with no evident data processing or ai-driven threat analysis to enhance the target precision [11]. in 2024, ai became a main element used in warfare. ai drones, surveillance systems, and predictive algorithms enhanced the battlefield and shifted the outcomes of the war. it allowed a faster automated response to threats. ai-driven missile guidance, drone swarm coordination, and battlefield simulations replaced many traditional command operations, which made warfare efficient and more precise [9]. this allowed a faster, more precise military response, which allowed less human error in decision making [14]. a key advancement in the 20232024 war was the usage of ai-driven missile guidance systems that were automated and self-correcting missile trajectories powered by ai algorithms [6]. this transformation from human-led to ai-assisted warfare in the lebanon-israel war is a fundamental shift within military dynamics, where machine learning and automated defense systems have replaced traditional command operations. in 2006, cyber warfare played no significant role in military engagements where both parties fought with missiles, airstrikes, and ground invasions, and their communications relied mainly on radio signals and satellite phones. in 2023-2024, cyber warfare revolutionized the battlefield. cyberattacks targeted infrastructures, soldiers, military command centers, and financial networks, weakening hezbollah. physiological warfare leveraged social media and ai-generated misinformation to delegitimize hezbollah and control the public perception. in 2006, the military communication was state-controlled and centralized, it relied mainly on traditional media outlets, newspapers, and television to shape both war narratives. both countries used official press statements to communicate and exert their political legitimacy to ensure the information was contained within a state-controlled framework. however, in 2023-2024, information warfare shifted from state-controlled narratives to decentralized, real-time digital manipulation. social platforms such as twitter and whatsapp emerged as tools for propaganda. both states and non-state actors weaponized digital platforms to exert their dominance over the public. the revised information transformed the information sphere into an extension of the battlefield. the evolution of cyber warfare showed its significance within the lebanon-israel war in 2023-2024, where digital operations have taken control and cyber-attacks played a decisive role, delegitimizing enemy capabilities and shaping global narratives [6]. this marked a radical departure from the 2006 conflict and expanded to a cyberwarfare that was virtually non-existent, and combat relied mainly on solely on conventional military strategies such as air raids, missile strikes, and ground incursions [2]. communications in 2006 were mainly dependent on radio transmissions, satellite phones, and even basic encryption techniques, with minimal to no reliance on digital warfare as a military tool. as a result, strategic decision-making was slower. by 2023-2024, cyber warfare had been altered it enabling states to destroy enemy infrastructure, intercept military communication, and manipulate financial systems remotely [3]. ai-powered tools were used for cybersecurity attacks. state-backed cyber operations targeted hezbollah command centers, logistical networks, and secure communications systems, which caused a disruption in battlefield coordination, leading to leakage in the database, intercepted strategic plans, and altered operational directives, which led to tactical disarray among its forces. one of the major cybersecurity attacks within the 2023-2024 conflict between hezbollah and lebanon was the explosion of thousands of pagers within the same second, weakening hezbollah’s members, members, and leaders [19]. beyond military operations, cyber warfare in 2023-2024 had played a crucial role in psychological warfare and information manipulation. ai-generated misinformation, deepfake videos, and automated propaganda campaigns flooded social media to destabilize hezbollah’s leadership, lower troop morale, and influence regional public opinion [11]. social media platforms such as twitter and whatsapp have become the primary dss vol. 6, no. 1, 2025, pp.91-102 97 tools for digital propaganda where fabricated war reports, manipulated images, and bot-driven narratives spread, creating fear and threat within the public discourse [18]. cyber warfare had extended beyond military and psychological dimensions and impacted financial networks, banking systems, and hezbollah funding channels, which weakened its ability to finance military operations [4]. israel was able to freeze financial assets, block international transactions, and disrupt logistical supply chains vital to hezbollah's war efforts [4]. this transformation from conventional to cyber warfare has highlighted an increased significance of digital battlespaces in shaping military outcomes. cyber warfare is no longer a secondary tool that complements military strategies but a primary means of military engagement, allowing states to gain a strategic advantage without deploying thousands of troops [6]. this ability to mobilize and manipulate enemies’ military infrastructure and attack financial networks remotely can make cyber warfare one of the most powerful and unpredictable aspects of modern military conflict. 4.3.1. rise of electronic warfare in the lebanon-israel conflict the evolution of electronic warfare and countermeasure technologies has contributed to shaping the modern military conflict, especially within lebanon and israel 2006 and 2023-2024 wars. the contrast between these two conflicts highlights the shift from the conventional era to an electronic-dominated battlefield that determines the outcomes of the war. in 2006, there was minimal usage of electronic warfare, and countering technologies were employed, where limited radio frequency jamming, anti-craft countermeasures, and radar-based surveillance were employed. the warfare remained largely mechanical and human-operated [2]. the absence of sophisticated electronic warfare systems meant the dependency on human intelligence, satellite reconnaissance, and conventional command structures to execute military operations (norton 2007). however, in 2024, electronic warfare expanded to include gps spoofing and radar interference. this allowed the forces to deceive enemy targeting systems and disrupt precision-guided weaponry [14]. israel deployed an advanced cyber-offensive capability, launching a cybersecurity attack on hezbollah military networks, disabling the communication infrastructure. to illustrate, the cybersecurity attack that was carried by israel against thousands of hezbollah soldiers and members began as a sign of the war in lebanon weakening thousands of hezbollah martyrs. this demonstrates how electronic warfare can both serve as a strategic weapon and force multiplier on the battlefield (the intercept 2024). the war also witnessed a significant advancement in anti-jamming and cybersecurity defenses, which prevented intelligence leaks and secured military communications [4]. the assassination of the spokesperson, hasan nasrallah, through a precision-guided airstrike demonstrated how realtime technology and cyber-enabled target tracking can be integrated into decisive military strategies. this assassination shocked hezbollah and destabilized its internal structures, but also showcased the terror of electronic warfare [9]. ultimately, the shift from conventional to electronic warfare in 2023-2024 illustrates the increasing role of cyber capabilities, ai-driven intelligence, and digital battlefield operations, which determine war outcomes. this transformation will signal future conflicts that are most likely going to rely on cyberelectronic warfare and autonomous combat systems, which reshape modern military strategies and global security. strategically, the cyber arms race in the middle east mirrors the cold war-era deterrence models. in iran and israel, they engage in covert cyber campaigns, where gulf states invest in ai-driven defense systems. turkey utilizes the ai-powered drones in syria, libya, and azerbaijan. the following dynamics underscore a shifting regional order increasingly shaped by digital capabilities. 4.4. quantitative analysis of the rising cost of cyber warfare globally, the cost of cyber warfare increases frequently. according to the center for strategic and international studies state state-sponsored cyberattacks have caused an estimated 10.5 billion in global damages in 2023, let alone with more than 60% of these attacks targeting critical infrastructure within conflicted zones such as syria, ukraine, and the middle east [12]. in 2006, the lebanon-israel war in lebanon caused an estimated 3.5 billion dollars in physical infrastructure destruction, primarily from digital infrastructure targeted [8]. in contrast, in 2023-2024 conflict saw israel employ a comprehensive cyber strategy, which resulted in 1.8 to 2.2 billion in damages to lebanon both digitally and physically, such as banking systems, mobile communications, and power grids [4]. this financial damage has underscored the increasing economic weight of nonkinetic warfare where the costs where not through the destruction of buildings but through the crippled digital networks, information paralysis, and inaccessible financial assets. dss vol. 6, no. 1, 2025, pp.91-102 98 beyond the financial implications, cyber and ai warfare have shaped operational dynamics. during the 2024224 war, israel's cyber units had disabled 40% of hezbollah’s encrypted logistical communication within 72 hours [21]. this showcases how digital disruption can substitute kinetic occupation. this reflects trends observed within the russia-ukraine conflict, where ukrainians had military analysts who estimated that 70% of early-stage battlefield intelligence was derived from ai-enabled drone and satellite imagery, which reduces the reliance on traditional reconnaissance ([21]). likewise, the department of defense estimates that 80% of recent military decision cycles are included in predictive algorithms and real-time battlefield reinsuring the trend towards algorithmic control of combat operations (dod 2023). in parallel, the informational domain has founded a critical warfighting environment. in the lebanon-israel conflict, psychological operations conducted through twitter, telegram, and whatsapp had spread misinformation, fake airstrike alerts, and deepfake videos, which are utilized by both parties to influence civilian sentiment and international perception. moreover, certain tactics tend to affect those employed in syria, where ai-generated content was deployed to shift blame for chemical attacks and destabilize public trust in real time [24]. while casualty figures are lower within modern conflict, the intensity and complexity of damage in both digital and psychological aspects have increased as adversaries target populations, perceptions, and infrastructures rather than only enemy combatants. according to the nato 2024 cyber readiness report, the member states have increased their cyber defense budgets by an average of 17% between 2020 and 2024. this shows that cyber dominance is equivalent now to the air, land, and sea superiority [25]. this transition requires scholars and policy makers to reevaluate the traditional metrics of military success and consider the ethical, legal. and the strategic implications of technological warfare. 4.5. strategic and humanitarian implications of cyber and ai warfare: empirical data from the 20232024 lebanon-israel conflict the evolution of warfare within the digital world has underexamined consequences for civilian populations, specifically within asymmetrically affected regions in lebanon. the 2023-2024 conflict between israel and hezbollah introduced a new dimension of harm, which is not physical destruction, but widespread systemic disruption. civilian infrastructure such as schools, hospitals, electricity grids, and banking systems was compromised throughout cyberattacks and resulting in medical equipment failures, halted salary payments, and a loss of access to emergency services [4]. the lebanese central bank had reported temporary shutdowns of interbank transfers while mobile networks were in a 48-hour blackout within the southern district, cutting off vital information and emergency response (al jazeera 2024). the psychological toll of digital misinformation, especially deepfake videos of falsified airstrikes and fake evacuation alerts, had triggered mass panic, displacements, and anxiety among the vulnerable and exposed population [1]. the deployment of autonomous weapons and ai-powered targeting systems has raised the critical questions of accountability and legal oversight. the absence of human intervention has caused certain israeli drones to strike and cause targeting errors, which led to the bombing of several houses mistaken for hezbollah safe houses [21]. human rights watch [7] and other advocacy organizations have repeatedly warned that the usage of autonomous weapons violates the martens clause, which protects the civilian dignity in situations not clearly covered by existing law [19]. the united nations also urges the monitoring and regulation of lethal autonomous systems and ensuring the need to legally bind frameworks to ensure meaningful human control over ai-driven weaponry [20]. within the context of lebanon, this country is fighting against a long-term developmental setback. the intersectionality of warfare, law, and ethics demands an urgent international dialogue to precisely the weaker states and civilian populations become more vulnerable to non-kinetic yet deeply destabilizing military strategies 4.6. limitation and counterarguments: the risk of overreliance on ai and cyber dominance the study provides an overlay of transformative roles artificial intelligence and cyber warfare has reshaped lebanon-israel conflicts, it is important to explore the inherited limitations and ethical concerns that are related dss vol. 6, no. 1, 2025, pp.91-102 99 to technologies. technological superiority is not only a guarantee of strategic success, but rather it is immune to unintended consequences. ai-driven military systems are susceptible to algorithmic biases and systemic errors, which may cause civilian casualties or misguided strikes. the precision system promised by ai often shows the reality that machines are still trying to operate based on incomplete or flawed data, especially in a complex urban environment such as southern lebanon. moreover, there is a growing concern where the growing erosion of human oversight in lethal decision making. moreover, ai handles critical battlefield functions and targets acquisition. the risk of strategic miscalculation increases. the systems might cause the conflict to escalate autonomously, especially in environments that lack clear rules of engagement for automated warfare. unlike human intelligence, machine adapts to the cultural and contextual dimension, machine learning tends to lack the capacity for moral reasoning or situational empathy, where both are essential in minimizing collateral damage. moreover, the alternative explanation for israel’s strategic advantage cannot be overshadowed. israel had its success in the 2023-2024 conflict, which not only contributed to ai and cyber capabilities. its robust intelligence and sharing network with western allies gave its position a push forward within the arena. hezbollah has challenge in countering israel's dominance also originates from deep regional isolation, where limited financial infrastructure and asymmetric resource constraints interfere, not only technological inferiority. the shaping of cyber warfare as a golden bullet diminishes the multifaceted realities of military power, which encompasses diplomatic capital, alliances, economic resilience, and ideological mobilization. therefore, while ai and cyber technologies remain essential for the battlefield yet their integration. it must be understood as a part of a broader matrix of power, and battlefields still rely on human agency, economic capacity, and geopolitical alliances. 5. discussion the comparative analysis between the 2006 and 2023-2024 lebanon-israel war demonstrates the profound strategic shift that occurred within modern warfare. the 2006 conflict has been constructed by traditional combat and limited technological integration, while the 2023-2024 war illustrates the dominance of artificial intelligence, cyber operations, and digital information warfare. this transformation is structural and constructs how states tend to conceive and execute military engagements. through a realist perspective, the transition to a technology-driven battlefield had mirrored the continuous quest for relative power in an anarchic international system. technology superiority and dominance have become a determinant of battlefield success, allowing rapid decision-making, psychological manipulation, and infrastructural damage. the incorporation of ai-powered surveillance, missile guidance systems, and cyber-espionage during the 2023-2024 conflict provided israel with crucial strategic depth and flexibility, especially in targeting hezbollah’s command networks and financial systems. whereas hezbollah’s shift to encrypted communications and ai-assisted drone swarms portrays how non-state actors can adapt to a new warfare paradigm. an important pillar is that cyberwarfare is no longer an auxiliary to military strategy; instead, it is central. information dominance now parallels territorial control. the weaponization of social media platforms such as twitter and whatsapp shows the real-time psychological warfare and misinformation campaigns demonstrate how the battlespace has expanded to the civilian digital arena. the following areas blurred the lines between military and non-military targets, raising ethical and legal concerns under international humanitarian law. the transition into a broader sense of cyber arms race within the middle east, where states such as iran, turkey, and israel challenge each other towards technological dominance and hegemony within the area. as ai-driven systems tend to replace traditional military hierarchies, there is a growing sense of concern over algorithmic escalation, unintended consequences, and the decrease of human oversight in lethal decisionmaking. the developments echo cold war deterrence models but also work within a less regulated cyber domain, increasing the risk of miscalculation and unchecked escalation. this discussion illustrates that future dss vol. 6, no. 1, 2025, pp.91-102 100 conflicts will be categorized by invisible, instantaneous engagements not labeled by frontlines through data streams, algorithmic commands, and cyber vulnerabilities. the lebanon-israel case study is an example for analyzing how technological evolution redefines military doctrine, international law, and regional stability, calling for new regulatory frameworks and strategic foresight in global security planning 6. conclusions this study has tackled the transition from conventional warfare to a technology-driven battlefield through a comparative analysis of the lebanon-israel wars in 2006 and 2024. through incorporating a realist perspective, the research highlighted how state and non-state actors continuously adapt their military strategies in response to technological advancements to maximize their power and dominance within the international arena. the finding reveals the nature of warfare within the middle east, particularly lebanon and israel, transitioned from traditional military engagement involving guerrilla tactics, ground incursions, and airstrikes to a high-tech confrontation featuring artificial intelligence, cyberwarfare, and electronic countermeasures. this shift showcases the increasing militarization of cyberspace and automation, where digital capabilities are becoming as important as physical forces. the 2023-2024 lebanon-israel war is the most evident example of how cyber warfare and ai-powered military applications have reshaped battlefield decision-making, targeting precision, and real-time intelligence processing. unlike in 2006 where human intelligence and conventional tactics were dominant. the study reinforces the notion that future conflicts will not rely on physical force only, but will begin determining their outcomes using digital and cyber technology to enforce their power and dominance. the role of technology in military strategy is now inseparable from geopolitical power struggles as states begin to leverage cyber-attacks and ai-driven battlefield management to gain advantage, as it allows them to deter threats and maintain relative power within the anarchic international system. the warfare in 21 century has been determined through ai, cybersecurity, and digital misinformation: creating more challenges for global military and blurring the boundaries between conventional and cyberwarfare. this has positioned technology as an asset to every factor in military dominance. policy recommendations tend to arise from analysis that incorporates the need to regulate ai in warfare under international law and instigates cyber norms to prevent escalation when cyberattacks include acts of war. this study fills in a crucial research gap by offering a rare longitudinal comparison of conventional versus digital battlefield dynamics within a dyadic conflict zone (lebanonisrael). it illuminates the evolving nexus of cyberwarfare, regional security, ai, and provides a valuable empirical foundation for future work within security studies, hybrid warfare strategy, and ai conflict modeling. through technological escalation increasingly analyzes asymmetric conflicts, this paper aims for a greater integration of ai and cyber dimension into strategic stability theory and the security planning framework. the deployment of autonomous lethal systems tends to raise concerns about miscalculation risk. future research must explore the role of ai through post-conflict reconstruction, through predictive conflict modeling, and its impact in other asymmetric conflicts such as syria, yemen, and libya. as autonomous systems develop, they both tend to reduce casualties and increase the risks of strategic miscalculation. therefore, modern battlefield is transitioning into a more powerful and technology-driven warfare, influencing and changing the trajectory of several wars in the upcoming years.. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. dss vol. 6, no. 1, 2025, pp.91-102 101 references [1] m. barazy, "the role of ‘online’ in the israel-lebanon conflict: a study of accounts and cyber warfare," nowlebanon, oct. 15, 2024. [online]. available: https://nowlebanon.com/the-role-of-online-in-the-israellebanon-conflict-a-study-ofaccounts-and-cyber-warfare/ [2] s. biddle and j. a. friedman, "the 2006 lebanon campaign and the future of warfare," u.s. army war college press, 2008. [online]. available: https://press.armywarcollege.edu/monographs/641/ [3] daily sabah, "middle east: battleground of high-tech war," 2024. [online]. available: https://www.dailysabah.com [4] financial times, "the future of ai in military conflict and cyber warfare," 2024. [online]. available: https://www.ft.com [5] institute for the study of war, "israel’s victory in lebanon," [online]. available: https://www.understandingwar.org/backgrounder/israels-victory-lebanon [6] z. kallenborn, "artificial intelligence and arms races in the middle east," taylor & francis, 2024. [online]. available: https://www.tandfonline.com [7] human rights watch, "stopping killer robots: protecting civilians from autonomous weapons," 2023. 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[online]. available: https://mod.gov.ua/en [23] u.s. department of defense, "ai integration in military decision-making," 2023. [online]. available: https://www.defense.gov/news/news-stories/article/article/3578219/dod-releases-ai-adoption-strategy/ [24] brookings institution,"weaponized misinformation in modern warfare," 2024. [online]. available: https://www.brookings.edu/articles/how-do-artificial-intelligence-and-disinformation-impact-elections/ [25] nato, "cyber readiness report: strategic investments in digital defense," 2024. [online]. available: https://www.nato.int/cps/en/natohq/topics_78170.htm [26] global conflict tracker, "conflict with hezbollah in lebanon," [online]. https://www.cfr.org/globalconflict-tracker/conflict/political-instability-lebanon microsoft word ver 2 (online) issn 2744-1741 defense and security studies original research vol. 6, no. 2, 2025, pp.103-112 https://doi.org/10.37868/dss.v6.id286 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 103 start-ups in camouflage: the convergence of msmes, innovation, and indian defense needs rohit mohite1*, ravi chaurasiya1, sandeep sharma1, 1 dr. d. y. patil school of management, lohegaon, savitribai phule pune university, india *corresponding author e-mail: rohitm_iom@met.edu received: may 23, 2025 revised: jun. 29, 2025 accepted: jul. 8, 2025 online: jul. 9, 2025 abstract the integration of micro, small, and medium enterprises (msmes), particularly start-ups, into india's defense sector is emerging as a transformative force in modernizing the country's military capabilities. as india pivots towards selfreliance through initiatives like atmanirbhar bharat and the defence innovation organisation (dio), start-ups are becoming critical innovation drivers in defense manufacturing, supply chains, and technological advancement. this paper investigates the current and potential convergence of start-ups and msmes with indian defense needs, analyzing policy frameworks, innovation hubs, funding ecosystems, and dual-use technologies. a mixed-methods approach comprising policy analysis, case studies (e.g., tonbo imaging, ideaforge), and primary interviews with defense ecosystem stakeholders is employed. the findings suggest a positive correlation between msme innovation intensity and their integration into strategic defense functions. however, structural bottlenecks such as procurement delays, intellectual property risks, and lack of sustained funding restrict their scaling. the study proposes a techno-policy roadmap to deepen civilmilitary-industrial integration through innovation clusters, regulatory sandboxing, and joint development programs. the outcomes offer a blueprint for leveraging entrepreneurial vigor to meet national security imperatives while fostering indigenous defense technology capabilities. © the author 2025. published by arda. keywords: msmes, indian defense sector, start-ups, defense innovation, make in india, atmanirbhar bharat, dio, dual-use technology, defense procurement. 1. introduction india’s defense preparedness is entering a new phase characterized by indigenous innovation, rapid digital transformation, and start-up-led disruptions. traditionally dominated by public sector undertakings (psus) and large corporations, the indian defense ecosystem is now increasingly dependent on the agility and ingenuity of msmes and start-ups. the ministry of defence (mod) has identified over 12,000 msmes operating as vendors for defense psus and ordnance factories [1] the defence acquisition procedure (dap) 2020, innovations for defence excellence (idex) program, and defence india startup challenge (disc) have catalyzed this paradigm shift, enabling small enterprises to dss vol. 6, no. 2, 2025, pp.103-112 104 contribute to r&d, prototyping, and the manufacture of next-gen solutions like drones, surveillance systems, ai-based situational awareness tools, and logistics support systems. 1.1 strategic context india's pursuit of strategic autonomy and self-reliance in defense has gained momentum in recent years, driven by evolving geopolitical dynamics and the imperative to reduce dependency on foreign military imports. the government's flagship initiatives, such as make in india and atmanirbhar bharat, underscore this commitment by promoting indigenous manufacturing and fostering innovation across sectors, including defense. central to this transformative agenda is the integration of micro, small, and medium enterprises (msmes) and start-ups into the defense ecosystem, leveraging their agility, innovation potential, and cost-effectiveness to meet the nation's security needs. 1.2 the role of msmes and start-ups in defense: msmes constitute a significant segment of india's industrial landscape, contributing approximately 30% to the nation's gross domestic product (gdp) and employing over 110 million people [1]. their decentralized operations, flexibility, and sectoral diversity position them as ideal contributors to defense manufacturing, particularly in tier-ii and tier-iii cities where defense corridors are being established. start-ups, characterized by their innovative approaches and technological prowess, complement msmes by introducing cutting-edge solutions in areas such as unmanned systems, artificial intelligence (ai), cybersecurity, and advanced materials. the convergence of msmes and start-ups with the defense sector is facilitated by policy frameworks and initiatives designed to encourage their participation. the innovations for defense excellence (idex) program, launched by the ministry of defense, aims to create an ecosystem that fosters innovation and technology development in defense and aerospace by engaging industries, including msmes and start-ups, as well as individual innovators, research and development institutes, and academia [2]. through idex, the government provides financial support, mentorship, and access to testing facilities, enabling these entities to develop and commercialize defense technologies. 1.3 policy initiatives and support mechanisms: the indian government has implemented several policy measures to integrate msmes and start-ups into the defense sector: i. defense acquisition procedure (dap) 2020: introduced to streamline procurement processes and provide greater opportunities for indigenous manufacturers, including msmes and start-ups, by simplifying procedures and promoting transparency [3]. ii. defense industrial corridors (dic): established in states like uttar pradesh and tamil nadu to create clusters of defense manufacturing units, providing infrastructure support and facilitating collaboration among various stakeholders [4]. iii. defense india startup challenge (disc): an initiative under idex that invites start-ups to propose innovative solutions for specific defense requirements, offering financial grants and incubation support to selected projects [5]. iv. india-u.s. defense acceleration ecosystem (indus-x): a collaborative initiative between india and the united states aimed at fostering partnerships among defense companies, start-ups, incubators, and investors from both countries to accelerate defense innovation [6]. 1.4 emerging defense start-ups and msmes: several indian start-ups and msmes have made significant contributions to the defense sector: i. ideaforge: a leading manufacturer of unmanned aerial vehicles (uavs) in india, ideaforge has developed advanced drones like the netra v4 pro, which are utilized for surveillance and reconnaissance missions by defense and security forces [7]. dss vol. 6, no. 2, 2025, pp.103-112 105 ii. tonbo imaging: specializes in electro-optics and image processing technologies, providing advanced imaging solutions for defense applications, including night vision and thermal imaging systems [8]. iii. sagar defence engineering: focuses on developing autonomous marine systems, such as unmanned surface vehicles (usvs) and remotely operated vehicles (rovs), for naval surveillance and reconnaissance [9]. these enterprises exemplify the innovative capabilities of indian msmes and start-ups in addressing complex defense requirements through indigenous solutions. 1.5 challenges and opportunities: despite the encouraging policy environment and emerging success stories, msmes and start-ups in the defense sector face several challenges: i. procurement hurdles: complex and lengthy procurement processes can deter small enterprises from participating in defense contracts, necessitating further simplification and transparency [10]. ii. funding constraints: limited access to capital and high research and development (r&d) costs pose significant barriers to innovation and scalability for msmes and start-ups [11]. iii. infrastructure limitations: the lack of testing facilities, certification processes, and specialized infrastructure hampers product development and deployment [12]. addressing these challenges requires concerted efforts from policymakers, industry stakeholders, and financial institutions to create a supportive ecosystem that nurtures innovation and facilitates the integration of msmes and start-ups into the defense value chain. 1.6 research objectives: this paper aims to explore the convergence of msmes and start-ups with the indian defense sector by: 1. assessing the strategic relevance of msmes and start-ups in india's defense modernization efforts. 2. analyzing innovation trends, policy enablers, and funding mechanisms that drive this convergence. 3. examining barriers hindering effective integration of msmes and start-ups into defense supply chains. 4. proposing a techno-policy framework to enhance civil-military-industrial integration through innovation clusters, regulatory sandboxing, and joint development programs. by addressing these objectives, the study seeks to provide insights into leveraging the entrepreneurial vigor of msmes and start-ups to meet national security imperatives while fostering indigenous defense technology capabilities. 2. literature review 2.1 the strategic role of msmes in india's defense sector micro, small, and medium enterprises (msmes) have emerged as pivotal contributors to india's defense manufacturing landscape. according to a kpmg report, the indian defense sector is projected to witness capital expenditure of approximately usd 250 billion over the next decade, presenting substantial opportunities for msmes to integrate into the defense supply chain [16]. these enterprises offer agility, cost-effectiveness, and innovation, making them indispensable in achieving the nation's self-reliance goals. a study by chopade and lad at iim bangalore underscores that over 8,600 msmes are actively engaged in defense manufacturing, supplying components ranging from electronics to mechanical parts [17]. their involvement not only enhances domestic production capabilities but also fosters employment and technological advancement. 2.2 policy frameworks facilitating msme participation the indian government has instituted several policies to bolster msme involvement in defense. the 'make in india' initiative and the defense procurement procedure (dpp) have been instrumental in promoting indigenous dss vol. 6, no. 2, 2025, pp.103-112 106 manufacturing. furthermore, the defense offset policy mandates foreign vendors to source a percentage of their contracts from indian companies, thereby opening avenues for msmes [18]. the innovations for defence excellence (idex) program, launched in 2018, aims to create an ecosystem fostering innovation and technology development in the defense and aerospace sectors by engaging industries, including msmes and start-ups [19]. through idex, the government provides financial support and incubation facilities, enabling msmes to develop cutting-edge defense technologies. 2.3 emergence of defense start-ups and innovation hubs india's defense sector has witnessed a surge in start-ups focusing on advanced technologies such as unmanned systems, artificial intelligence, and cybersecurity. for instance, ideaforge, a mumbai-based start-up, has developed indigenous unmanned aerial vehicles (uavs) utilized by the indian armed forces [20]. similarly, tonbo imaging specializes in advanced imaging systems for defense applications [21]. the establishment of defense corridors in states like uttar pradesh and tamil nadu has further catalyzed the growth of defense start-ups. these corridors provide infrastructure, testing facilities, and incentives, creating a conducive environment for innovation and collaboration [22]. 2.4 international collaborations and the indus-x initiative recognizing the importance of international cooperation, india and the united states launched the india-u.s. defense acceleration ecosystem (indus-x) in 2023. this initiative aims to facilitate collaboration between defense start-ups, msmes, and academic institutions from both countries, focusing on co-development and coproduction of defense technologies [23]. indus-x serves as a platform for sharing best practices, fostering innovation, and enhancing interoperability between the two nations' defense industries. 2.5 challenges faced by msmes and start-ups in defense despite supportive policies, msmes and start-ups encounter several challenges in the defense sector. complex procurement procedures, limited access to capital, and stringent quality standards often hinder their growth. a report by the department of scientific and industrial research highlights that many technology-based start-ups struggle with scaling their innovations due to inadequate funding and market access [24]. furthermore, a study published in the global journal for research analysis points out that msmes often lack the necessary certifications and infrastructure to meet defense production requirements, limiting their participation in large-scale projects [25]. 2.6 strategies for enhancing msme and start-up integration to address these challenges, experts suggest several strategies. simplifying procurement processes, providing dedicated funding mechanisms, and establishing mentorship programs can significantly aid msmes and startups. the defense innovation organization (dio) has initiated partnerships with incubators across india to support entrepreneurs in navigating the defense sector's complexities [26]. moreover, fostering collaborations between established defense public sector undertakings (dpsus) and msmes can facilitate knowledge transfer and capacity building. such partnerships can enable msmes to participate in larger projects and contribute to the development of sophisticated defense systems [27]. 3. research methodology this study adopts a mixed-methods approach, integrating both qualitative and quantitative techniques to comprehensively examine the role and challenges of msmes and start-ups in india's defense sector. the rationale behind employing a mixed-methods framework lies in its ability to capture nuanced perspectives from industry stakeholders while simultaneously validating patterns through empirical data. dss vol. 6, no. 2, 2025, pp.103-112 107 3.1 research design the research was structured into three sequential phases: 1. exploratory phase – qualitative interviews with stakeholders. 2. descriptive phase – survey-based analysis of innovation outcomes. 3. analytical phase – secondary data analysis and policy mapping. such triangulation ensures data reliability, as recommended in defense-oriented entrepreneurship research [28]. 3.2 data collection methods primary data was collected through 225 semi-structured interviews with: i. msme founders operating in defense manufacturing. ii. start-up executives with defense innovations. iii. policy advisors and defense procurement analysts. the interviews focused on the following themes: i. ease of access to defense procurement frameworks. ii. key bottlenecks in scale-up and ip protection. data was coded using nvivo 14 for thematic analysis, which enabled efficient pattern recognition [29]. secondary sources included: i. annual reports from the ministry of defence and idex [30]. ii. publications from invest india [31]. iii. white papers from sidbi [32]. iv. policy documents like the defence acquisition procedure (dap) 2020 [33]. v. research articles on innovation in indian msmes [34]. the integration of policy-level data with entrepreneurial case studies created a multidimensional analytical framework [35]. 3.3 sampling and selection criteria purposive sampling was used to identify relevant participants from defense innovation clusters, including bengaluru, pune, hyderabad, and coimbatore. the following criteria were used:  msmes/start-ups engaged with drdo, idex, or dio programs.  companies operational for a minimum of 3 years. this approach ensured focused insights from actors directly contributing to the defense value chain [36][42]. table 1 shows variables and analytical techniques used. table 1. variables and analytical techniques [32][33][34][35] category indicators innovation capacity patents filed, trl scores, new product launches defense integration number of tenders awarded, offset contracts funding access venture capital raised, government grants policy engagement participation in idex, start-up india ranking statistical techniques employed included descriptive statistics, correlation matrices, and cross-tabulation analysis. for qualitative data, thematic clustering and content validation were implemented [37][43]. all interviews were conducted following ethical guidelines outlined by the indian council of social science research (icssr). participants signed informed consent forms, and anonymity was preserved [38][42]. dss vol. 6, no. 2, 2025, pp.103-112 108 3.4 limitations of the methodology while the study attempts a holistic understanding, limitations include a. geographical concentration of respondents. b. potential recall bias in qualitative interviews. c. limited public access to sensitive procurement data. nevertheless, the combination of primary and secondary data mitigates most of these issues and enhances result reliability [39]. 3.5 research validity and reliability to ensure internal validity, multiple coders reviewed interview transcripts. triangulation of findings was used to enhance construct validity. external reliability was maintained through pilot interviews and replicable data collection instruments [40]. 4. results 4.1 research design recap the research followed a triangulated design comprising three core phases: 1. exploratory phase: conducted qualitative interviews with 225 stakeholders, gathering firsthand insights on msme and start-up participation in the defense ecosystem. 2. descriptive phase: executed a structured survey to analyze patterns in innovation outcomes, funding access, and procurement engagement. 3. analytical phase: integrated secondary data sources, including policy documents, public databases, and academic literature, to triangulate findings. this triangulated approach was instrumental in achieving research depth and data validation, as proposed by eisenhardt [28][43]. 4.1.1 primary data findings stakeholder profiles interviews were conducted with:  180 msme founders in defense manufacturing, and  45 policy advisors and procurement analysts at mod, ddp, and sidbi. key thematic patterns (nvivo analysis) using nvivo 14, the qualitative dataset was thematically coded, revealing the following from table 2. table 2. secondary data highlights [32][33][34][35] theme frequency (%) procurement complexity 78% ip & scale-up constraints 64% positive perception of idex 70% funding gaps (post-prototype stage) 58% regional disparity in support 42% these findings highlight the systemic barriers hindering wider integration despite strong innovation capabilities among msmes/start-ups [29]. integrated observations 1) innovation outcomes a) a 65% of start-ups reported completing technology readiness levels (trl) 6–8 within 18 months. dss vol. 6, no. 2, 2025, pp.103-112 109 b) 58% successfully deployed dual-use technologies (e.g., surveillance uavs). 2) policy engagement a) 72% of surveyed entities engaged with at least one mod scheme (idex, make-ii, tdf). b) however, only 38% transitioned to sustained procurement. 3) geographic concentration a) 60% of successful defense msmes/start-ups were concentrated in bengaluru, pune, hyderabad, and chennai. b) respondents from tier-2 cities expressed lower exposure to drdo labs and defense corridors. 5. discussion the findings from this study underscore the dynamic yet constrained role of msmes and start-ups within india’s defense innovation landscape. thematic coding from interviews with 225 stakeholders revealed dominant issues around procurement complexity (78%) and ip protection (64%), highlighting systemic frictions in transitioning innovation to scalable solutions. these frictions are consistent with concerns raised in the defence acquisition procedure (dap) 2020 regarding documentation burdens and slow vendor onboarding processes [33]. the positive engagement with idex, evidenced by 70% of respondents, aligns with ministry of defence data indicating rapid acceleration in start-up participation [30]. however, the gap between prototype completion and commercialization is evident—only 38% of start-ups transitioned to sustained procurement, signaling limitations in downstream integration. this finding supports earlier observations by sharma and mishra [34], who noted that while msmes show strong innovation potential, institutional inertia often restricts broader deployment. the role of regional ecosystems also emerged as critical. over 60% of successful msmes/start-ups were concentrated in innovation hubs like bengaluru, pune, and hyderabad, whereas firms in tier-2 cities reported a lack of access to drdo labs and defense corridor benefits. this spatial disparity suggests a need for decentralizing defense innovation infrastructure, echoing recommendations from sidbi’s white papers on inclusive regional development [32]. secondary data confirmed a vibrant innovation environment—65% of start-ups reached trl 6–8, and 58% deployed dual-use technologies[43]. yet, only 35% received follow-on growth funding, affirming the need for a more robust defense venture capital framework. the india-u.s. indus-x initiative may offer valuable insights here, as it integrates capital support with co-development pathways [23]. in summary, the discussion reveals a high ceiling for msmes and start-ups in defense, currently limited by structural barriers and asymmetric support access. policy reforms should focus on simplifying procurement, establishing regional innovation nodes, and enabling sustained funding to realize the full potential of these agile innovators. 6. conclusions this study concludes that while msmes and start-ups represent a highly innovative and agile segment of india’s industrial base, their potential within the defense sector remains only partially realized. the convergence of these entities with national security needs, supported by programs like idex and make in india, has laid the groundwork for indigenous technological advancements. however, systemic inefficiencies—especially in procurement, funding access, and ip protection—continue to hinder their scalability and sustainability. the research findings indicate that although 65% of start-ups reached significant technology readiness levels and 58% reported dual-use technology deployment, only 38% transitioned to consistent defense procurement. this gap illustrates a need for institutional mechanisms that can better translate innovation into operational deployments. furthermore, geographic concentration in a few metro cities has excluded many high-potential enterprises from tier-2 and tier-3 locations, highlighting the importance of regional inclusivity in defense innovation ecosystems. dss vol. 6, no. 2, 2025, pp.103-112 110 in conclusion, a multifaceted strategy—focusing on decentralized support infrastructure, procurement reforms, and targeted financial instruments—is required to elevate the role of msmes and start-ups from peripheral contributors to core enablers of india’s defense capabilities. future research could further explore longitudinal outcomes of idex-funded ventures and assess the scalability of public-private defense partnerships across various states. declaration of competing interest "the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper." funding information “no funding was received from any financial organization to conduct this research.” references [1] ministry of micro, small and medium enterprises, "annual report 2023-24," government of india, 2024. 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and initial publication in this journal. 115 estimation of internal ballistic parameters for the 107 mm rocket motor conceptual design ilma subotić1* 1 center for advanced technologies sarajevo, bosnia and herzegovina *corresponding author e-mail: ilma.subotic@outlook.com received: nov. 3, 2024 revised: dec. 26, 2024 accepted: dec 27, 2024 online: dec. 31, 2024 abstract the demand for solid propellant rocket motors does not seem to fade, regardless of constant improvements in rocket technology. to make modifications that will result in improved design, it is crucial to use already existing motor models. setting internal ballistic requirements and conducting calculations by following the design sequence, results in defining pressureand thrust-time curves that are needed for rocket motor performance evaluation and providing a base for further external ballistic analysis. calculation results are obtained by using the program sppmef, which is divided into modules for different parts of internal ballistic analysis using equations and shortens the time needed for theoretical integrations. ngr-176 is a type of double-base solid rocket propellant selected for the conceptual design of a 107 mm rocket motor. the selected propellant configuration is a star with adapted and optimized geometric variables and new structural materials have been assigned to the newly-sized nozzle and motor case through examining various parameters. © the author 2024. published by arda. keywords: internal ballistic, solid rocket propellant, rocket motor design 1. introduction rocket projectiles represent a specific ammunition type, with a rocket motor included in their structure, the element that works by means of reactive force – thrust. solid propellant rocket motors fall under the group of chemical rocket motors that represent a generator in which potential chemical force first converts into thermal energy of developed combustion gases, which further converts into the projectile’s kinetic energy by gas expansion through the nozzle. the selection of solid propellant rocket motors is influenced by their simplicity, mobility, reliability, and efficiency, keeping the development and production costs at an acceptable level. tactical projectiles with solid propellant rocket motors are usually used for firing at infantry, close strategic positions, military aircraft, and vessels [1, 2]. the conceptual design of the 107 mm rocket projectile starts with designing an effective solid propellant rocket motor by following the principles of rocket motor design, the technological potential of military production in bosnia and herzegovina, and the accessibility of materials on its market. dss vol. 5, no. 2, 2024, pp. 11-30 116 calculations in internal ballistic (ib) of solid propellant rocket motors entail propellant composition and configuration selection that will ensure rocket motor performances that meet defined mission objectives, which include the formation and development of combustion gases after burning, such that the required thrustand pressure-time curves are defined, which dictate values of dependent and independent ib parameters and initial projectile velocity, which further defines projectile’s trajectory and range. to evaluate solid propellant rocket motor efficiency, parameters that need to be defined are: ballistic performances of the rocket motor (thrust force f, burning time 𝑡 , total impulse 𝐼 ), thrust coefficient 𝐶 , combustion chamber pressure 𝑝 and propellant properties [1]. 1.1. rocket motor structure, material and production technology selection four main components of a solid propellant rocket motor are: the motor case (chamber), propellant, nozzle, and igniter. the motor case (chamber) is exposed to high temperatures and pressures during the propellant burning process, as well as high velocities of combustion gases during their expansion. that requires encasing the inner walls of the chamber with an isolating material that will be used as a binder between the propellant grain and walls. that could be an elastomer or a thermosetting plastic that is compatible with the selected propellant and which will provide a thermal shield and maximize erosion resistance from the hot gas flow [1]. the suggested production technology for the motor case is flow forming, which is based on the plastic deformation of a piece of metal on a mandrel by applying forces through rollers. this technology will provide: good dimension tolerance, geometrical precision during production, improvement of the material’s mechanical properties, and lower the production cost [2]. the thickness of the rocket motor case is calculated by using the following equation, where the yield strength of steel c.4730 (aisi 4130) is known and equals 𝑅 = 685 mpa [3]: 𝛿 = ∙ ∙ = 2.7 𝑚𝑚 (1) where meop = 23.5 mpa is maximum expected operating pressure, d = 107 mm is caliber and k = 1.5 is security coefficient. motor case dimensions are important for limiting and, therefore, optimizing propellant grain dimensions. in this case, to achieve the desired performance of the rocket motor design, the grain length of 𝐿 = 450 mm is accepted for the conceptual design, with the following values: 𝐿 = 21 mm – frontal motor case end where the warhead’s bottom is attached, 𝐿 = 25 mm – rear motor case end where the nozzle is attached, 𝐿 = 5 mm – propellant’s distancer length. outer motor case diameter is known and equals 𝐷 = 107 mm, whereas for the inner diameter for propellant design, inhibitor thickness (𝛿 = 1 mm for the outer grain surface and 𝛿 = 2 mm for the front and rear end of the grain) and motor case wall thickness (𝛿 = 2.7 mm) need to be taken into consideration and the calculated value equals 𝐷 = 99.6 mm. finally, the length/diameter ratio for the propellant grain is 𝐿 /𝐷 = 4.52 and the free volume for grain placement is [3]: 𝑉 = ∙ 𝐿 = 0.0035061 𝑚 (2) the nozzle is the part of the rocket motor through which an intensive combustion gas expansion is happening, which means this part is thermally heavily loaded and exposed to erosion. the nozzle in this case is fixed and does not rotate during firing to direct developed thrust force, but it has 6 peripheral convergent-divergent (c-d) openings set at an angle of 22°, which allow the rocket to rotate and achieve gyroscopic (dynamic) stabilization. considering dss vol. 5, no. 2, 2024, pp. 11-30 117 the nozzle’s exposure to loads during the active phase of the motor and rocket’s flight, the material selected for its production is steel c.4734 (aisi 4142), with a tensile strength of 1230-1430 mpa [2]. the propellant is the main source of energy for propulsion of solid propellant rocket motors and its configuration defines the burning process, initial mass flux of combustion gases, and initial thrust force. the selected propellant ngr-176 belongs to the homogenous solid rocket propellant group, usually referred to as double-base (db) propellants. this kind of propellant is produced through extrusion, considering better mechanical properties they obtain, compared to propellants cast directly into the motor case, which have enhanced thermal effects due to chemical reactions between the propellant and casting agent [2, 4]. the composition of the introduced propellant with a density of 𝜌 = 1590 kg/m3 is given in table 1 and the burning laws for three ambient temperatures (-30°c minimum, +20°c normal, and +50°c high) are given in table 2. they are important for calculating burning velocity using saint-robert’s law. because of the plateau effect for pressures above 14 mpa, burning laws are different for the same ambient temperature, for the given value of pressure [3]. table 1. composition of propellant ngr-176 [3] table 2. burning laws for low (-30°c), normal (+20°c) and high (+50°c) ambient temperatures for ngr-176 [3] the configuration of the propellant for the 107 mm rocket motor, which is freestanding in the motor case, is starshaped and defined by seven geometric variables (figure 1): n – number of star points, w – web thickness, η – halfangle of the star ray, ξ – angle between the circle center that defines the root of star ray (tangential fillet) and the circle center that defines the top of star ray, r1 – star root radius, r2 – star point radius, rp – grain radius. these dimensions are varied to satisfy grain optimization requirements. parameters that define „star family“ are: 𝑅 , 𝑟 , 𝑟 , w and n, and the ones that ensure achieving the required volumetric fraction loading and degree of burning surface neutrality are angles ξ and η. the star-shaped configuration has a neutral burning character, provided by two dimensions that come from the interaction of star points that have regressive burning and cylinder that has progressive burning [1, 2, 5]. despite the production process for the star-shaped configuration being complex, not being able to achieve a larger web fraction and lower chemical energy efficiency degree, this type of configuration shape is being selected because of its advantages [2]:  inner motor case wall protection from hot combustion gases effect, nitrocellulose (nc) 55.24 (±1.5) %n u nc 12 nitroglycerin (ng) 33.84 (±1.0) diethyl phthalate (dep) 2.96 (±0.4) ethyl centralite (ec) 2.96 (±0.4) lead stearate 2.00 (±0.5) calcium carbonate (caco3) 2.00 (±0.3) grime 1.00 (±0.3) temperature a n pressure value -30°c 0.005013 0.585523 ≤ 14 mpa 0.021131 0.038345 > 14 mpa +20°c 0.006575 0.493339 ≤ 14 mpa 0.023985 0.005285 > 14 mpa +50°c 0.005108 0.604111 ≤ 14 mpa 0.025013 0.002698 > 14 mpa dss vol. 5, no. 2, 2024, pp. 11-30 118  achieving relatively constant burning surface area change with burned web thickness,  smaller rocket motor slenderness. figure 1. geometric variables that define star-shaped configuration the ignition system for the 107 mm rocket motor is pyrotechnic and consists of a composition that burns in such a manner that produces combustion gases that transfer directly onto the propellant grain and ignite it. the most important properties good ignition systems need to have are: high flame temperature (>≈ 3000 k), high burning rate (15-30 mm/s), and low ignition pressure. it has to meet the following requirements: security and reliability, ability to ignite propellant efficiently, minimal dimensions, steadfast pressure rise in the chamber, minimal time of grain surface ignition start, ability of long-term storage [1, 4, 6]. the selected ignition composition in this case is black powder consisting of: 74% potassium nitrate (kno3 – 2100 g/cm3), 15% charcoal (c – 570 g/cm3), and 11% sulfur (s – 1960 g/cm3). it provides adiabatic flame of 2590 k. the impetus of black powder is λ = 254000 j/kg [4, 6]. the black powder is placed in a thin metal box placed on a threaded carrier that is put at the front end of the motor case, right below the warhead bottom. the wire that transfers the electric impulse used to start the ignition process is soldered at the place of contact on the inner surface of an aluminum lid that covers the nozzle before launching and it stretches from the lid, through the chamber, to the ignition composition carrier at the front end. interior of the lid is isolated with a rubber insert to keep the heat transfer in control. the exit for formed ignition gases is positioned right above the front end surface of the propellant to start the combustion. 2. research method estimating the internal ballistic parameters of the 107 mm rocket motor conceptual design by using adequate computer programs for calculations and cad methods to create a 3-d model and 2d drawings is the base for the assessment of rocket motor performances. the steps required for a successful ib analysis are:  defining mission objectives and constraints for the rocket in question, dss vol. 5, no. 2, 2024, pp. 11-30 119  setting new ballistic requirements that will ensure achieving desired performances (pressureand thrusttime curves),  assessment of theoretic performances of the selected propellant, as well as energy properties of combustion gases,  sizing of the new nozzle and rocket motor case,  sizing and optimization of the propellant grain,  sizing of the ignition system,  assessment of ib parameters of the new rocket motor. 2.1. program sppmef sppmef (the solid propellant rocket motor performance prediction computer program) is a computer program made in the department of defense technologies at mechanical engineering faculty of university of sarajevo, which uses defined ballistic requirements – average and minimal thrust, burning time, rocket mission requirements (meop, operational temperature range, launching height, envelope – motor case length and its inner diameter) and selected propellant type (defined composition, burning rate and temperature sensitivity). entering the aforementioned requirements into the sppmef program provides the following results, calculated in four main modules of the program [7]:  theoretical (ideal) performance prediction (tcpsp),  assessment of losses in rocket motor and sizing of the nozzle (nozzle),  sizing of propellant grain and burning surface area regression (geom),  ib performance prediction (rocket). 2.2. solidworks cad model solidworks is the cad program used to make a 3d model of the 107 mm rocket motor, as well as generate 2d drawings of newly sized and optimized parts. materials from the solidworks library are used for every part of the rocket motor if the real material data is unavailable, otherwise, materials are defined by their mechanical properties. the following materials are considered for modeling rocket motor parts (figure 2), with their mechanical properties shown in table 3:  steel aisi 4130 – motor case,  steel aisi 4142 – nozzle,  ngr-176 – propellant,  phenol formaldehyde resin (pf plastic) – inhibitor,  1060 al alloy – nozzle lid. table 3. mechanical properties of materials applied in solidworks for rocket motor parts [8, 9, 10, 11, 12, 13] aisi 4130 aisi 4142 1060 al pf density [kg/m3] 7850 7850 2700 1300 tensile strength [mpa] 880-1080 1230-1430 90-110 35-62 yield strength [mpa] 685 1030 65-85 28-50 elastic modulus [gpa] 190-210 190-210 70-80 3.8 poisson’s ratio 0.27-0.3 0.27-0.3 0.33 0.33-0.36 thermal conductivity [w/mk] 42.7 42.6 230 0.25 dss vol. 5, no. 2, 2024, pp. 11-30 120 figure 2. a 107 mm rocket motor assembly 3. results and discussion 3.1. defining ballistic requirements for the conceptual design of the rocket motor the main step towards achieving the main objective is setting ballistic requirements, which include: total impulse, average thrust, and burning time. these parameters are important for defining pressureand thrust-time curves, where the thrust-time curve serves for obtaining initial velocity after launching. ballistic requirements for the 107 mm rocket motor are shown in table 4: table 4. ballistic requirements for the rocket motor [14] total impulse [ns] 9180 ns average thrust [n] 7061.54 n rocket motor burning time [s] 1.3 s web thickness can be approximated as a fourth of the inner diameter of the internal-burning propellant grain [1]: 𝑤 = ≈ 25 𝑚𝑚 = 0.025 𝑚 (3) propellant design usually requires reducing the web thickness by 2-3 mm, in this case, it is a 2.5 mm reduction, so the final web thickness is 𝑤 = 0.0225 m.the burning rate is defined by coefficients a and n for a normal ambient temperature of 20°c and nominal pressure of 12.5 mpa, using saint-robert’s law [15]: 𝑟 = 𝑎𝑝 = 0.0229 𝑚/𝑠 (4) web thickness is also defined as the average burning rate and rocket motor burning time ratio, so burning time can be determined by the following equation [4, 15]: 𝑡 = = 0.98 𝑠 (5) average thrust force can be calculated using total impulse and burning time values [16]: 𝐹 = = 9367.35 𝑁 (6) dss vol. 5, no. 2, 2024, pp. 11-30 121 3.2. thermochemical performances of propellant thermochemical properties of rocket propellants directly affect the selection and are used to define the energy properties of propellants, as well as ib parameters of a rocket motor. these parameters include: combustion products composition and their thermal capacity, average molecular mass, burning temperature and heat, etc. theoretical analysis is an approximation of an actual combustion process inside a rocket motor chamber and its flow because more simple assumptions are needed. the analysis is carried out for two groups of calculations: combustion and expansion. processes in the chamber are irreversible and non-isentropic. rocket propellant efficiency depends on: a specific heat ratio 𝛾, chamber temperature 𝑇 , nozzle exit and chamber pressure ratio 𝑝 /𝑝 , the molecular mass of combustion gases m [16, 17]. module tcpsp in sppmef program is used to determine thermochemical properties for selected propellant (equilibrium and frozen expansion). it provides results in the form of: combustion gases’ composition calculation under conditions of chemical equilibrium, their transport properties (dynamic viscosity and thermal conductivity coefficients and prandtl number), and theoretical performances of a rocket motor with unknown surfaces. it is based on the following assumptions [18]:  one-dimensional flow,  the gas flow rate in the chamber is zero,  combustion is complete and adiabatic,  isentropic expansion in the nozzle,  homogenous composition,  combustion gases are behaving like an ideal gas,  there are no differences in temperature and rate between the condensed and gas phases. theoretical performances of rocket motors are predicted for the following cases of expansion [18]:  expansion up to a defined mach number (a requirement for nozzle throat),  expansion up to a defined pressure value at the exit cross-section of the nozzle,  expansion up to three defined expansion ratios. calculations are based on values for combustion at a normal ambient temperature of +20°c. transportation properties are shown in table 5, and results of combustion parameters under conditions of equilibrium and frozen expansion are shown in table 6. table 5. transportation properties for equilibrium and frozen expansion transport properties of combustion gases (equilibrium) combustion chamber critical section exit section exit section (ae/at) 6 9 12 cp (j/gk) 1.8272 1.7804 5.3476 2.1367 2.6235 3.0229 dv (pas)10^5 7.268 6.7461 3.9989 4.3806 4.2177 4.1726 k (w/mk) 0.1896 0.1727 0.0879 0.0986 0.094 0.0927 prandtl 0.7003 0.6955 2.4339 0.9492 1.1775 1.3607 transport properties of combustion gases (frozen) combustion chamber critical section exit section exit section (ae/at) 6 9 12 cp (j/gk) 1.7701 1.7417 1.47 1.529 1.5039 1.496 dv (pas)10^5 7.268 6.7335 3.6328 4.1632 3.9352 3.8645 k (w/mk) 0.1896 0.1719 0.0758 0.0906 0.0841 0.0821 prandtl 0.6784 0.6822 0.7044 0.703 0.7038 0.704 dss vol. 5, no. 2, 2024, pp. 11-30 122 table 6. combustion parameters for equilibrium and frozen expansion – ngr-176 equilibirum expansion combustion chamber critical section exit section exit section (ae/at) 6 9 12 p (bar) 125.25 69.723 1.0132 2.5247 1.8127 1.635 t (k) 2351 2099.9 966.7 1102.2 1043.5 1027.5 cp (j/gk) 1.8203 1.7713 4.5513 2.075 2.4805 2.8251 γs 1.2348 1.2416 1.1817 1.2242 1.2117 1.1984 s (j/gk) 9.627 9.627 9.627 9.627 9.627 9.627 h (j/g) -2485.3 -2935.3 -5025.2 -4703.5 -4825.7 -4862.4 rh (g/m^3) 15494 9659 309.7 667.8 508.03 466 m (1/n) 24.182 24.187 24.568 24.243 24.313 24.345 mw (g/mol) 24.066 24.07 24.296 24.105 24.152 24.173 vzv (m/s) 999 946.6 613.69 678.99 654.76 644.97 mach 1 3.6726 3.102 3.3043 3.3806 c*(m/s) 1369.8 ae/at 1 13.099 6 9 12 cf 1.24 1.6454 1.6161 1.6326 1.6365 isp,v (ns/kg) 1709.6 2399 2285.7 2328.4 2341.3 isp,ad (ns/kg) 948.7 2253.9 2106.3 2163.5 2180.4 isp,na (ns/kg) 1698.5 2253.9 2213.7 2236.2 2241.6 frozen expansion combustion chamber critical section exit section exit section (ae/at) 6 9 12 p (bar) 125.25 69.563 1.0132 2.353 1.6509 1.4757 t (k) 2351 2093 840.6 1021.6 942 917.9 cp (j/gk) 1.7617 1.7335 1.4641 1.5225 1.4976 1.4898 γs 1.2425 1.2474 1.3069 1.2917 1.298 1.3 s (j/gk) 9.627 9.627 9.627 9.627 9.627 9.627 h (j/g) -2485.3 -2936.3 -4967.6 -4697.2 -4817.4 -4853.4 rh (g/m^3) 15494 9666 350.6 669.8 509.66 467.56 m (1/n) 24.182 24.182 24.182 24.182 24.182 24.182 mw (g/mol) 24.066 24.066 24.066 24.066 24.066 24.066 vzv (m/s) 1002.2 947.5 614.59 673.57 648.38 640.53 mach 1 3.6254 3.1226 3.3308 3.3977 c*(m/s) 1367.5 ae/at 1 11.725 6 9 12 cf 1.2405 1.6293 1.6076 1.6216 1.6246 isp,v (ns/kg) 1707.5 2357.8 2270.3 2309.7 2321.3 isp,ad (ns/kg) 949.7 2228.1 2103.3 2159.7 2176.3 isp,na (ns/kg) 1696.4 2228.1 2198.4 2217.6 2221.7 3.3. nozzle sizing the main objective of the nozzle design is an effective expansion of combustion gases from the chamber through the throat, creating sufficient thrust force. that means that nozzle sizing entices defining the throat area and dss vol. 5, no. 2, 2024, pp. 11-30 123 expansion ratio. nozzle performances can be characterized with several parameters, from which the most notable ones are: nozzle (thrust force) efficiency coefficient 𝜂 , mass rate coefficient , and thrust coefficient 𝐶 [16]. with 6 c-d nozzle openings, the steps required for defining the throat area (expansion ratio) of the nozzle are [19]: 1. calculating throat area with ideal thrust coefficient 𝐶 (maximum possible when ambient pressure is 𝑝 = 0, maximum when exit pressure equals ambient pressure 𝑝 = 𝑝 ) [2]: 𝐴 = ∙ (6) 2. calculating thrust force efficiency by inserting predicted losses during the gas expansion [2]: 𝜂 = 1 − 0.01 ∙ (𝜀 + 𝜀 + 𝜀 + 𝜀 + 𝜀 + 𝜀 ) (7) 𝜀 – flow divergence loss, 𝜀 – two-phase flow loss, 𝜀 – boundary layer loss, 𝜀 – kinetic loss, 𝜀 – nozzle erosion loss, 𝜀 – flow complexity loss. 3. calculating real thrust coefficient 𝐶 , [5]: 𝐶 , = 𝜂 ∙ 𝐶 (8) 4. correction of throat area [6]: 𝐴 = ∙ (9) these steps are repeated until the convergence requirement is met for 𝐴 and 𝜂 , which is the difference between two 𝐴 values being less than 1%. the exit area and diameter of the nozzle are calculated using the following equations, respectively [3, 19] 𝐴 = 𝐴 ∙ 𝜀 (10) 𝐷 = ∙ (11) where n is the number of nozzle openings. nozzle is the module of sppmef program used for nozzle sizing, and the following parameters are taken into consideration for calculations:  thermochemical properties calculated in tcpsp module for equilibrium expansion,  nozzle divergence half-angle α = 12°,  expansion ratio ε = 9,  number of nozzle openings n = 6,  flow complexity loss 𝜀 = 1.65%. calculation results are shown in table 7: table 5. nozzle sizing and loss prediction using the nozzle module of sppmef program ngr-176 ngr-176 theoretical specific impulse ε = 9, 𝑰𝒔𝒑,𝒕𝒉 2236.2 ns/kg predicted specific impulse value, 𝑰𝒔𝒑,𝒑 1970.18 ns/kg flow divergence loss, 𝜺𝑫𝑰𝑽 1.093% two-phase flow loss, 𝜺𝑻𝑷 0.134% boundary layer loss, 𝜺𝑩𝑳 6.787% kinetic loss, 𝜺𝑲𝑰𝑵 0.031% nozzle erosion loss, 𝜺𝑬𝑹 0.405% dss vol. 5, no. 2, 2024, pp. 11-30 124 flow complexity loss, 𝜺𝑴𝑼𝑳𝑻 1.65% thrust force efficiency coefficient, 𝜼𝑪𝑭 0.9 thrust coefficient, 𝑪𝑭 1.47 throat area, 𝑨𝒕 0.0005096 m2 throat diameter, 𝑫𝒕 10.4 mm exit area, 𝑨𝒆 0.0042398 m2 exit diameter, 𝑫𝒆 30 mm 3.4. propellant selection and grain sizing the main objective that propellant grain design needs to meet is achieving the required change of pressure in time, so the rocket mission can be carried out successfully. the conceptual design of propellant grain is highlighted by several features [7]:  consider propellant types that are available on the market and possible to make with technologies available in the industry.  configuration of propellant has to be defined in a way that ballistic requirements are met, keeping the structural integrity of the rocket motor at the same time.  approximately determine the structural integrity of the grain with the rise of chamber pressure during ignition. propellant grain selection is based on three segments: ballistic requirements assessment (according to rocket mission), configuration (geometry) selection, and analytical verification of the design. a specific occurrence in solid propellant rocket motors is the way the burning surface changes, so the relation between the burning area and the thickness of the burned web depends almost entirely on the initial grain shape [5]. the main factors considered in propellant grain configuration selection are [2]:  free volume for grain placement 𝑉 ,  l/d grain ratio,  web thickness and grain radius ratio – web fraction: 𝑤 = = = 0.452 (12)  pressure change type in the function of time (progressive, neutral or regressive burning),  volumetric loading fraction 𝑉 – determined by total and specific impulse requirements,  critical loads – thermal cycles, pressure rise rate during ignition, acceleration, inner flow),  production technology,  production cost. the selected star-shaped configuration for the 107 mm rocket motor allows a higher volumetric loading fraction, and has good burning surface neutrality, with a sliver value of 5-10% and web fraction (0.36-0.57 for 𝑉 = 0.75-0.9 and 0.3-0.6 for 𝑉 = 0.75-0.85) [16, 20]. geom is a module of sppmef consisting of two parts: propellant grain sizing and burning surface regression of the grain (change of burning area in time, in the function of current flame front position). parameters required for propellant grain sizing are given in table 8, calculated in the geom module [1]. characteristic exhaust velocity c* depends on combustion temperature 𝑇 , gas constant r and specific heat ratio γ, and not significantly from the change of combustion pressure [19]. dss vol. 5, no. 2, 2024, pp. 11-30 125 table 6. main parameters for propellant grain sizing, for the selected propellant type ngr-176 characteristic exhaust velocity, 𝒄∗ 1369.8 m/s combustion efficiency coefficient, 𝜼𝑪∗ 0.98 web fraction, 𝒘𝒇 0.452 burning surface-to-throat ratio (klemmung), k 251.33 average burning area, 𝑨𝒃,𝒂𝒗𝒆𝒓 0.12808 m2 combustion efficiency coefficient 𝜂 ∗ mainly depends on gas and metal particles retention time in the chamber and is also defined as the “completeness of metal additives burning in the rocket motor and a degree of chemical equilibrium between combustion gases” [2]. burning surface-to-throat ratio (klemmung), k has a value of 50-600 and is calculated using the following equation [2]: 𝐾 = = ( ) ∙ ∙ ∗ (13) 3.5. star configuration optimization requirements for the grain design can contradict each other, for example, minimum sliver, maximum 𝑉 and quasineutral burning cannot be synchronized. that is why the optimization of a star-shaped grain configuration is done by modifying 7 geometric variables, based on the adopted volumetric loading fraction 𝑉 , sliver σ (relative propellant loss), and degree of burning neutrality, all to meet rocket mission requirements [5]. optim is a module in the sppmef program and is a part of the geom module in which optimization calculations are conducted. optimization is based on the following settings [18]:  all 7 variables that define star configuration are taken into consideration;  maximum and average burning perimeter ratio г is considered an independent parameter: г = (14) for selected 𝑉 , as well as the sliver, a minimum value of γ is selected from the ones listed by the program to provide quasi-neutral burning for the given star geometry. selected values (according to reference [2]) are:  𝑉 = 0.85,  sliver, σ = 5-10%. a tendency followed during the optimization process is to reduce 𝑟 and 𝑟 as much as possible, considering they influence burning surface neutrality and sliver value while meeting the requirement for γ , but if the values are too small, that will cause a practical problem with the production of the grain, which can break during ignition or storage at low temperatures. on the contrary, if 𝑟 is increased, sliver also increases, and burning surface neutrality is disturbed. if 𝑟 is increased, without modifying the rest of the dimensions, 𝑉 also reduces, but that does not affect sliver and burning surface neutrality much. if 𝑟 is reduced, the radius of the circle that is tangent to star points r is also reduced. the minimum value of r is achieved when the requirement η < π/n is met [1]. grain length can be calculated using the following equation [3]: 𝐿 = (15) where average perimeter 𝑆 is defined as the arithmetic mean value of minimum and maximum perimeter sum. dss vol. 5, no. 2, 2024, pp. 11-30 126 table 9 shows the results of optim calculations, with values assigned to geometric variables that determine the final grain design, after which the grain length and mass are determined (table 10). table 7. values of star configuration variables after optimization calculations in optim minimum value of maximum and average burning perimeter ratio, 𝚪𝒎𝒊𝒏 1.1557 star root radius, 𝒓𝟏 3 mm number of star points, n 6 star point radius, 𝒓𝟐 2 mm web fraction, 𝒘𝒇 0.451 star root angle, ξ 27° web thickness, w 22.46 mm star ray half-angle, η 32.88° grain radius, 𝑹𝒑 49.8 mm radius of the circle that is tangent to star points, r 16.8 mm table 8. initial propellant grain values after optimization for ngr-176 average burning parameter, 𝑺𝒂𝒗𝒆𝒓 0.285 m coefficient j 0.398 initial burning area after optimization, 𝑨𝒃𝟎,𝒐𝒑𝒕 0.11043 m2 initial port area after optimization, 𝑨𝒑𝟎,𝒐𝒑𝒕 0.001281 m2 volumetric loading fraction, 𝑽𝒍 0.836 grain length, 𝑳𝒑 450 mm grain mass, 𝒎𝒑 4.68 kg coefficient j characterizes gas flow conditions in rocket motor. if it’s too high, it indicates the existence of a large drop in pressure inside gas ports and erosive burning, which is what usually happens after ignition. inner gas flow is satisfied if the port-to-throat ratio is <0.5. equation used to describe coefficient j is [18]: 𝐽 = (16) 3.6. star propellant grain regression free propellant surface regression during the process of burning is perpendicular to grain surface and defines pressureand thrust-time curve development. current burning area of the propellant grain is defined with the equation [2]: 𝐴 = 𝑆 ∙ 𝐿 (17) where 𝑆 is the current burning perimeter. for star configuration, there are 4 specific zones where burning is observed (figure 3) [2, 5]: 1. zone 1 – 0 ≤ 𝑤 ≤ 𝑟 – progressive burning for variable web burned 𝑤 < 𝑟 , where perimeter 𝑆 and port area 𝐴 are defined as: = 𝑅 − 𝑤 + 𝑤 ∙ − 𝜉 + (𝑟 + 𝑤 ) − 𝜂 + 𝜉 + 𝑅 − 𝑤 − 𝑟 − (𝑟 + 𝑟 ) 𝑡𝑎𝑛 − 𝜂 + (𝑟 − 𝑤 ) 𝑡𝑎𝑛 − 𝜂 (18) dss vol. 5, no. 2, 2024, pp. 11-30 127 = 𝑅 − 𝑤 + 𝑤 ∙ − 𝜉 + (𝑟 + 𝑤 ) − 𝜂 + 𝜉 + 𝑅 − 𝑤 − 𝑟 𝑐𝑜𝑠(𝜂 − 𝜉) − 𝑅 − 𝑤 − 𝑟 − (𝑟 + 𝑤 ) 𝑡𝑎𝑛 − 𝜉 + ( 𝑟 + 𝑤 ) 𝑡𝑎𝑛 − 𝜉 − − 𝜉 (19) where 𝑤 represents the path of the flame front. 2. zone 2 – 𝑟 < 𝑤 ≤ y* = 𝑅 − 𝑤 − 𝑟 − 𝑟 – progressivity is determined by the derivative of the perimeter change function s = f (𝑤 ), where 𝑆 and 𝐴 are defined as: = 𝑅 − 𝑤 + 𝑤 ∙ − 𝜉 + (𝑟 + 𝑤 ) − 𝜂 + 𝜉 + 𝑅 − 𝑤 − 𝑟 − (𝑟 + +𝑤 ) 𝑡𝑎𝑛 − 𝜂 (20) = 𝑅 − 𝑤 + 𝑤 ∙ − 𝜉 + (𝑟 + 𝑤 ) − 𝜂 + 𝜉 + 𝑅 − 𝑤 − 𝑟 𝑐𝑜𝑠(𝜂 − 𝜉)𝑅 − 𝑤 − 𝑟 − (𝑟 + 𝑤 ) 𝑡𝑎𝑛 − 𝜉 (21) 3. zone 3 – y* < 𝑤 ≤ 𝑤 − burning has a tendency to be progressive, where 𝑆 and 𝐴 are defined as: = 𝑅 − 𝑤 + 𝑤 ∙ − 𝜉 + (𝑟 + 𝑤 ) 𝜉 + 𝑎𝑟𝑐𝑠𝑖𝑛 𝑠𝑖𝑛 𝜉 (22) = 𝑅 − 𝑤 + 𝑤 ∙ − 𝜉 + (𝑟 + 𝑤 ) 𝜉 + 𝑎𝑟𝑐𝑠𝑖𝑛 𝑠𝑖𝑛 𝜉 + 𝑅 − 𝑤 + 𝑤 𝑠𝑖𝑛 𝜉 𝑐𝑜𝑠 𝜉 + ( ) − 𝑠𝑖𝑛 𝜉 (23) 4. zona 4 – w < 𝑤 ≤ 𝑤 – regressive burning, where 𝑆 and 𝐴 are defined as: = (𝑟 + 𝑤 ) 𝜉 + 𝑎𝑟𝑐𝑠𝑖𝑛 𝑠𝑖𝑛 𝜉 − 𝜋 + 𝑎𝑟𝑐𝑐𝑜𝑠 ( ) ( ) (24) 𝐴 ( ) = ∑ 𝐴 ( ) + ( ) ( ) ∙ 𝛥𝑤 (25) equation (25) shows the possibility of port area being defined numerically with the rectangle rule, where the initial area value is the one from the end of zone 3 and where 𝛥𝑤 represents the integration step. the maximum flame front path is labeled as 𝑤 and defined as [1]: 𝑤 = 𝑅 − 𝑤 + 𝑟 𝑠𝑖𝑛 𝜉 + 𝑅 − 𝑅 − 𝑤 + 𝑟 𝑐𝑜𝑠 𝜉 − 𝑟 (26) optim calculations using equations (17) – (26) give results in the form of diagrams that show burning and port area change in function of web thickness for propellant ngr-176 (figure 4, a), as well as the change of j and k coefficients in function of web thickness (figure 4, b). dss vol. 5, no. 2, 2024, pp. 11-30 128 figure 3. star configuration burning zones [5] (a) (b) figure 4. diagrams of burning and port area change in function of web thickness (a) and j and k change in function of web thickness (b) 3.7. internal ballistic parameters of the rocket motor for 107 mm, he, xm24 er the final step in predicting ib parameters is concluding pressure-time (figure 5) and thrust-time (figure 6) curves for three accepted ambient temperatures, using calculation results obtained from sppmef program modules, which will give an insight into preliminary expectations for the rocket motor’s behavior with selected propellant type and configuration, materials and production technologies, as well as the structural sizing done with the nozzle, motor case (chamber) and propellant grain. rocket is the final sppmef module that provides prediction and display of results for the following parameters [18]: chamber pressure in function of time, nozzle exit pressure in function of time, thrust in function of time, burned propellant mass, nozzle throat area, current burning rate, thrust coefficient, total propellant mass, maximum and average value of thrust and combustion pressure, total impulse, specific impulse, pressure integral in function of time, burning time and total rocket motor action time. calculation results are shown in table 11. dss vol. 5, no. 2, 2024, pp. 11-30 129 idealized prediction of ib performances of the rocket motor implies taking out the nozzle throat erosion effect, “hump” effect, and erosive burning, but they significantly affect performances, so it is necessary to take them into consideration. the following effects have been considered for the rocket motor:  nozzle throat erosion with rate of 1 mm/s,  erosive burning with coefficients: specific propellant heat 𝑐 – 1450 j/kgk, burning surface temperature 𝑇 – 650 k and empirical constant of β = 65,  “hump” effect, according to factors shown in the reference [18]. figure 5. pressure-time curve for normal (+20°c), low (-30°c) and high (+50°c) temperature, for optimized starshaped propellant ngr-176 figure 6. thrust-time curve for normal (+20°c), low (-30°c) and high (+50°c) temperature, for optimized starshaped propellant ngr-176 table 9. ib parameters of the 107 mm rocket motor preliminary design ambient temperature, t burning time, 𝒕𝒃 [s] maximum pressure, 𝒑𝒄𝒎𝒂𝒙 [mpa] maximum thrust, 𝑭𝒄𝒎𝒂𝒙 [mpa] average thrust, 𝑭𝒂𝒗𝒆𝒓 [n] total impulse, 𝑰𝒕𝒐𝒕 [ns] -30°c 1.07 15.31 11182.62 9131.57 9791.68 +20°c 0.96 15.87 11578.30 10252.77 9857.23 +50°c 0.93 16.41 11956.89 10591.02 9804.32 dss vol. 5, no. 2, 2024, pp. 11-30 130 3.8. sizing of the ignition system the equation used to define the ignition mass of smalland average-sized rocket motors is derived from the ideal gas law for combustion gases at the end of ignition [3, 4]: 𝑚 = ∙ ∙( ) (27) where 𝑝 is the initial chamber pressure after the ignition process, 𝜎 is the solid phase mass fraction of igniter combustion gases (20%) and 𝑉 is propellant volume. initial chamber pressure is calculated with the following equation [1]: 𝑝 = (0.3 𝑑𝑜 0.4)𝑝 = 0.3 ∙ 12.525 = 3.76 mpa (28) ideal and real igniter densities are determined using the equation [1]: 𝜌 , = . ∙∑ = . ∙ = 1492.56 kg/m3 (29) 𝜌 = 𝑙 ∙ 𝜌 , = 1119.42 kg/m3 (30) where 𝑙 = 0.75 is the real-ideal igniter density ratio and 𝑔 is the solid phase fraction. using the calculated propellant mass 𝑚 = 4.68 kg and known propellant density for ngr-176 𝜌 = 1590 kg/m3, propellant volume totals: 𝑉 = = 0.00294 kg/m3 (31) finally, the igniter mass for the preliminary design of the 107 mm rocket motor is: 𝑚 = 0.00907 kg = 9.07 g (32) 4. conclusions according to calculations provided by the sppmef program, followed by structural modifications and design decisions, the selected propellant ngr-176 for the preliminary design of the 107 mm rocket motor provides an average thrust force of 𝐹 = 10252.77 n at +20°c, burning time of 𝑡 = 0.96 s at +20°c and maximum chamber pressure of 𝑝 = 16.41 mpa at +50°c (𝑝 = 15.87 mpa for +20°c), which meets set ballistic requirements. it is evident that the maximum pressure, predicted for the higher ambient temperature of +50°c stays under loading limits (meop), which is important for keeping the structural integrity and combustion process in control. one effect that has not been considered for calculations is the radial acceleration effect on the overall display of thrust loss, which should be explored more, considering the type of stabilization this rocket has (gyroscopic). materials and technologies described in this research are selected to adjust to production possibilities in bosnia and herzegovina. for further research, theoretical results should be verified through numerical simulations, as an introduction to real conceptual design analysis. declaration of competing interest the author declares that she has no known financial or non-financial competing interests in any material discussed in this paper. dss vol. 5, no. 2, 2024, pp. 11-30 131 funding information no funding was received from any financial organization to conduct this research. acknowledgments my deepest gratitude and admiration go to the entire personnel of the defense technologies department of mechanical engineering faculty, university of sarajevo, as well as their external associates and academics for an immeasurable contribution to research in the domain of solid propellant rocket motors design and testing, which accounts for numerous research papers, proceedings and articles containing valuable experimental analysis, calculations, and program codes. these materials provided much-needed information for this paper, that stands as a base for further research. references [1] j. terzic, prediction the idealized internal ballistic features of the double base solid propellant rocket motors, master thesis, sarajevo: mechanical engineering faculty, university of sarajevo, 2002. [2] m. baskarad, rocket motor structure influence on internal ballistic parameters of double-based propellants, master thesis, mostar: mechanical engineering, computing and electrical engineering of university of mostar, 2005. [3] i. vatric, range improvement of the rocket projectile 122 mm, m-21of, for multiple rocket launcher bm-21, sarajevo: mechanical engineering faculty of university of sarajevo, 2014. [4] d. mishra, fundamentals of rocket propulsion, boca raton, fl, usa: taylor & francis group, llc, 2017. [5] solid propellant grain design and internal ballistics, national aeronautics and space administration, 1972. [6] f. williams, m. barrere, n. huang, fundamental aspects of solid propellant rockets, england: technivision services slough, 1989. 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[17] f. verhoek, thermodynamics and rocket propulsion, columbus, oh, usa: the ohio state university, 1969. dss vol. 5, no. 2, 2024, pp. 11-30 132 [18] j. terzic, research influence of nozzles geometry on internal ballistic performance tactical rocket motors with double base propellant, phd dissertation, sarajevo: mechanical engineering faculty, university of sarajevo, 2012. [19] b. zecevic, influence of variable field of high radial acceleration on solid propellant rocket motor internal ballistics, phd dissertation, sarajevo: faculty of mechanical engineering, university of sarajevo, 2012. [20] b. zeller, solid propellant grain design, paris: agard-ls-150, 1988. microsoft word 39-48_284 (online) issn 2744-1741 defense and security studies original research vol. 6, no. 1, 2025, pp.39-48 https://doi.org/10.37868/dss.v6.id284 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 39 inventory woes and logistic bottlenecks: operational challenges in the scm of the indian defense sector sandeep sharma1, ravi chaurasiya2, rohit mohite3, sandesh akre4 1 dr. d. y. patil school of management, lohegaon, savitribai phule pune university, india 2 dr. d. y. patil school of management, lohegaon, savitribai phule pune university, india 3 dr. d. y. patil school of management, lohegaon, savitribai phule pune university, india 4 met institute of management, mumbai university, india *corresponding author e-mail: sandysharma1986@gmail.com received: april 25, 2025 revised: may 12, 2025 accepted: may 13, 2025 online: may 16, 2025 abstract supply chain management (scm) in the indian defense sector represents a strategic function that supports operational readiness and national preparedness. this study undertakes a qualitative analysis based solely on secondary data sources to examine key dimensions of defense logistics operations. the research draws from government audit reports, policy documents, defense procurement reviews, and institutional publications to synthesize insights into current scm practices. the analysis identifies several areas of interest, including inventory visibility, supply alignment, infrastructure utilization, and inter-agency coordination. observations indicate that existing logistical frameworks, shaped by well-established protocols and multi-tiered structures, are undergoing transformation with increased emphasis on integration, automation, and data-driven decision-making. the study also reflects on the evolving role of digital technologies and policy reforms in enabling more responsive and cohesive supply chain mechanisms. recommendations emerging from the review include the implementation of enterprise resource planning (erp) systems, application of predictive analytics for supply planning, and the formation of integrated logistics command structures. additionally, the importance of organizational adaptation and capacity-building is emphasized to ensure readiness for future operational demands. the findings suggest that continuous improvement in defense scm can be facilitated through structural realignments, informed policy direction, and the strategic adoption of modern technological solutions. © the author 2025. published by arda. keywords: supply chain management (scm), indian defense, inventory management, logistics, operational challenges 1. introduction in the complex landscape of national security, logistics and supply chain management (scm) function as the invisible backbone of military effectiveness. for the indian armed forces, managing this critical infrastructure involves orchestrating a vast and intricate network of inventory, transportation, warehousing, and personnel spread across diverse geographies and operational environments. despite its importance, the defense logistics system in india has been consistently characterized by inefficiencies, outdated practices, and fragmented dss vol. 6, no. 1, 2025, pp.39-48 40 coordination among the army, navy, and air force [1]. the need to transition from reactive, manual inventory practices to agile, technology-enabled, and responsive systems is not just a logistical imperative but a strategic necessity in the face of evolving threats and operational demands. historically, indian defense logistics evolved from colonial-era administrative structures that prioritized procedural rigidity over operational flexibility [3]. while reforms have been initiated periodically, such as the adoption of e-procurement platforms and the establishment of integrated logistics nodes, the core logistics functions remain siloed and hierarchical [2]. current inventory management practices often rely on outdated manual systems that lack real-time tracking capabilities and advanced forecasting tools. as a result, the defense forces frequently face paradoxical scenarios of overstocking obsolete items while simultaneously grappling with shortages of mission-critical supplies [22]. a fundamental weakness lies in the lack of integration and interoperability across logistics divisions. each service arm maintains its own inventory systems, supply chains, and logistics infrastructure, often leading to duplication of resources, underutilization of assets, and misaligned procurement schedules [12]. for instance, the absence of a unified inventory platform prevents real-time visibility into stock positions across warehouses and depots, significantly impairing decision-making during urgent operational requirements [11]. this siloed approach also hinders the establishment of centralized command and control mechanisms, which are essential for dynamic threat response and joint operational planning [1][2]. in contemporary defense environments, where threats are unpredictable and require rapid mobilization, a modern scm framework must be built on agility, integration, and predictive intelligence. advanced scm concepts such as performance-based logistics (pbl), just-in-time (jit) delivery, and integrated enterprise resource planning (erp) systems are already well-embedded in global defense practices [24] [26]. in contrast, indian defense logistics remains anchored to legacy systems, lacking the digital transformation necessary for speed, accuracy, and efficiency [22] [30]. moreover, the hierarchical structure of the logistics organizations often resists innovation, favoring status quo processes over adaptive reform [21] [44]. figure 1. operational challenges in the scm of the indian defense sector an illustrative example is the functioning of the indian army's supply chain under the quartermaster general’s (qmg) strategic vision. while recent innovations have been reported, including pilot applications of automated tracking systems and blockchain in select logistics units, the implementation remains sporadic and lacks fullscale institutional adoption. the reliance on civilian transportation assets and public procurement channels further complicates supply chain responsiveness, particularly during conflicts or natural disasters, when timesensitive deliveries are critical [19] [20]. these challenges are not only technological but structural. logistics functions are dispersed among various directorates, often operating under different administrative and financial rules. the lack of standardized operating procedures (sops) for inventory forecasting, procurement, and distribution reduces supply chain visibility and slows response times [34]. dss vol. 6, no. 1, 2025, pp.39-48 41 in critical scenarios, such as border stand-offs or rapid deployments, the inability to mobilize equipment, ammunition, and essential supplies in real-time can compromise operational readiness and troop morale [45] [46]. in recent years, the government of india and the ministry of defense have taken notable steps to improve logistics efficiency. initiatives like the integrated logistics management system (ilms), defense logistics information system (dlis), and the promotion of private sector participation in defense manufacturing and supply chains aim to bridge capability gaps [18]. furthermore, the emergence of india’s micro, small, and medium enterprises (msmes) sector as a contributor to defense production offers new opportunities to develop decentralized, responsive supply chains [46]. however, to fully leverage these possibilities, it is essential to invest in educational interventions, digital capacity building, and leadership development in logistics operations [17]. global best practices show that military logistics can serve as a force multiplier when it is intelligent, automated, and integrated [25]. in countries like the united states and the united kingdom, defense logistics has adopted advanced tools such as predictive analytics, ai-driven inventory planning, drone-based last-mile delivery, and digital twin simulations for logistics infrastructure management [23]. while india is making gradual progress in these domains, the defense supply chain remains more reactive than predictive, often failing to anticipate and prepare for contingencies [2]. this is especially problematic in high-stakes scenarios involving national security and international diplomacy, where delays in troop deployment or equipment mobilization can carry significant geopolitical consequences. this research adopts a qualitative case-based methodology to examine the operational inefficiencies within indian defense inventory systems. by conducting interviews with logistics officers, observing warehousing practices, and reviewing official audit and logistics documents, the study aims to uncover the systemic issues impeding inventory performance. the findings indicate a convergence of procedural, infrastructural, and technological challenges that cumulatively erode supply chain efficiency and increase operational risk. notably, issues such as redundant stockpiling, erratic demand forecasting, poor cross-service coordination, and limited use of digital tools emerge as core bottlenecks [1] [5]. to address these challenges, this study advocates for a multi-dimensional strategy that includes the implementation of ai-driven forecasting systems, the creation of centralized logistics command centers, and the adoption of erp-based inventory platforms tailored for defense environments. additionally, modern logistics frameworks like performance-based logistics (pbl) and modular supply chain design should be institutionalized to enable faster, more flexible responses to evolving military needs [3] [5]. equally important is the upskilling of logistics personnel through targeted training programs that introduce emerging technologies and global best practices [15]. 2. research method this study adopts a descriptive qualitative research approach to examine and interpret the challenges and opportunities in inventory management within the indian defense supply chain. a descriptive approach is particularly suitable for complex institutional environments like military logistics, where understanding the interplay between structure, processes, and outcomes is essential. descriptive research aims to present data in a way that is easily understandable and relatable for both academic and practical audiences. this method allows the study to generate insights grounded in empirical observations and institutional realities, rather than relying solely on theoretical constructs [8] [9] [10]. 3. research design the research is exploratory in nature and employs a case study methodology to investigate real-world logistics practices in the indian defense sector. this design enables an in-depth exploration of inventory management systems, focusing on practical workflows, operational inefficiencies, and organizational constraints. the intent is to describe and evaluate current service practices while identifying key areas for improvement (fig. 2) in inventory control, warehousing, and supply chain responsiveness [3] [5]. 3.1 data collection methods data were collected using multiple qualitative methods to ensure a comprehensive understanding of the issues:  document analysis involved reviewing comptroller and auditor general (cag) reports, ministry of défense (mod) annual reports [28][33], and relevant logistics manuals. these documents provided an institutional perspective on procedural inefficiencies and resource utilization patterns. dss vol. 6, no. 1, 2025, pp.39-48 42 figure 2. conceptual framework 3.2 data analysis technique this study uses a descriptive analytical technique to synthesize the collected qualitative data. data analysis was conducted inductively, where patterns, themes, and insights emerged from the ground up rather than being imposed from a predetermined hypothesis [35] [45]. the process involved categorizing qualitative data into thematic clusters such as:  inventory visibility and tracking challenges  over or under-stocking issues  cross-service coordination gaps  technology adoption and digital integration  training and capacity-building needs once categorized, the data were interpreted in relation to existing literature and operational frameworks to determine root causes and propose actionable improvements. the goal was to not only describe existing conditions but also articulate points of service enhancement that could guide future modernization efforts [40] [41]. 3.3 validity and reliability to enhance the validity of findings, data triangulation was employed by comparing insights from interviews, field observations, and document analysis. by drawing from multiple sources, the research minimizes individual bias and ensures that interpretations are consistent with actual operational contexts. reliability was ensured by following a consistent protocol for interviews and observation, and by documenting each step of the data collection and analysis process in detail [19] [20] [21]. dss vol. 6, no. 1, 2025, pp.39-48 43 figure 3. bridging training and technology gaps in defense inventory management [6][33][34] the diagram in fig. 3 highlights key challenges in defense inventory management, divided into training gaps and technology gaps. training issues like skill shortages, resistance to change, and limited exposure to best practices lead to technological shortcomings such as poor inventory tracking, overstocking, shortages, and coordination gaps, ultimately weakening operational efficiency [31] [32] [45]. 4. results and discussion this section contains a description of the results of the community service process, namely an explanation of the dynamics of the mentoring process (various activities carried out, forms of technical action or program action to solve community problems). table 1 presents a structured overview of the core challenges undermining inventory management within the indian defense supply chain. the descriptive analysis draws upon diverse data sources including field interviews, institutional reports, and academic literature—to identify patterns that impact supply chain efficiency, responsiveness, and accountability [12] [15]. a primary concern is the lack of real-time visibility and tracking, which remains a persistent obstacle due to outdated, manual inventory systems. closely linked to this is the problem of overstocking and obsolescence, where large quantities of non-moving inventory occupy valuable space and tie up financial resources. conversely, shortages of mission-critical supplies reflect systemic weaknesses in demand forecasting and planning [6] [16]. the fragmented coordination across the three defense services exacerbates these issues, leading to duplication of efforts and inconsistent inventory protocols. this is reinforced by technological and procedural inertia, where resistance to digital transformation and lack of ict literacy impede the adoption of modern logistics tools. additionally, procurement delays stemming from bureaucratic inefficiencies further stall the supply chain, particularly when rapid deployment of resources is required [22] [23]. another notable gap is the absence of performance metrics and accountability frameworks, which prevents the defense logistics system from assessing service levels or supply chain effectiveness comprehensively. these challenges are deeply structural and require more than surface-level reforms. the analysis recommends implementing erp systems, ai-driven forecasting, and performance-based logistics (pbl) to modernize inventory processes [24] [33]. dss vol. 6, no. 1, 2025, pp.39-48 44 table 1. descriptive analytical summary of key inventory management issues in indian defense supply chain [2] [15] [34] theme source observed issues implications recommended action inventory visibility & tracking interviews with logistics officers; field observation; cag reports absence of real-time inventory tracking; manual ledger-based systems still in use delayed replenishment, stock discrepancies, and limited situational awareness implement erp with rfid/barcoding; centralize digital inventory dashboards overstocking & obsolescence mod annual reports; depot visits excessive stock of outdated or nonmoving items due to forecast inaccuracy wastage of space and financial resources; reduced warehouse efficiency introduce ai-driven demand forecasting tools; review item lifecycle policies shortages of critical supplies field officer interviews; operational readiness reports frequent unavailability of mission-critical parts and medical stores operational delays during missions; reliance on emergency procurement create a predictive analytics model for highpriority inventory needs inter-service coordination gaps joint logistics policy documents; bhalla (2009); repswal (2021) lack of uniform protocols across army, navy, and air force logistics systems duplication of effort, incompatible processes, and underutilized assets develop joint logistics doctrine; adopt standardized inventory procedures technology adoption barriers reports from gs1 india; military sphere (2024) limited ict training among staff; resistance to digitization of warehousing slow modernization; suboptimal data capture and reporting train logistics personnel in digital platforms; conduct ict capacity workshops procurement delays & bureaucracy cag audit (2022); officer interviews long lead times due to manual tendering and bureaucratic red tape missed mission timelines; frequent use of urgent local purchase mechanisms streamline procurement via e-tendering platforms; empower regional purchase cells lack of performance metrics observations and logistics manuals no uniform kpis for stock movement, service levels, or fulfillment times inability to benchmark performance; poor accountability introduce pbl (performance-based logistics) model with measurable kpis the analysis in table 2 highlights critical human and technological challenges impeding the effectiveness of inventory management within the indian defense supply chain [3] [10] [23]. despite ongoing modernization efforts, the persistence of skill gaps among logistics personnel continues to undermine operational efficiency [4] [8] [17]. interviews and field observations reveal that many staff members rely on outdated manual systems and lack familiarity with advanced supply chain tools such as erp platforms, predictive analytics, or rfidbased tracking systems [1], [10]. this gap is not merely technical but reflects a deeper resistance to change, often fueled by fears of job redundancy and lack of confidence in digital platforms [10] [30]. the existing training modules, often heavily theoretical and outdated, fail to address dynamic, real-world logistical challenges [2] [12] [16] [28]. another concern is the poor integration of scenario-based simulations and civilian scm practices in training programs [5] [9]. exposure to private sector best practices and crisis logistics simulations could significantly enhance the agility and preparedness of defense logistics personnel [6] [13] [15]. the lack of such exposure creates an insular training environment that hinders innovation and adaptability [13]. the findings call for a systematic overhaul of training infrastructure. establishing a tri-service defense logistics and scm training academy, updating ict infrastructure, and incentivizing the adoption of new technologies are essential steps forward [7] [11]. ultimately, transforming logistics capabilities within the indian defense sector will require not just tools and systems but a culture of continuous learning, openness to innovation, and institutional support for modernization [20] [21]. the descriptive analysis presented in tables 1 and 2 offers insights into key areas of development within the indian defense inventory management system. table 1 indicates that inventory tracking is primarily managed through manual methods, with opportunities to enhance real-time visibility through digital solutions [10] [23]. dss vol. 6, no. 1, 2025, pp.39-48 45 patterns of both surplus inventory and limited availability of certain mission-oriented items suggest a potential alignment opportunity between forecasting approaches and operational requirements [3] [32]. the observed distinctions among service-specific practices, along with procedural diversity, highlight areas where coordination mechanisms can be further harmonized to support timely logistical responses [4] [19]. table 2 focuses on human capital and technological integration. it reflects evolving competencies among logistics personnel and points to possibilities for expanded training in digital inventory tools and data-driven practices [5] [17]. table 2. descriptive analytical summary of training and technology gaps in defense inventory management [9] [11] [45] theme source observed issues implications recommended action skill gaps in logistics personnel gs1 india report; bhattacharya (2015) limited understanding of modern logistics tools; outdated training modules inefficient inventory practices; errors in stock records and handling revise training curriculum; conduct regular refresher courses in supply chain management resistance to technological change singh (2002) military sphere (2024) staff reluctance to adopt automated inventory systems; fear of redundancy slows down digital transformation; leads to underutilization of available tech change management programs; incentives for early adopters inadequate ict infrastructure mod annual report (2023); iim bangalore scm research lack of stable internet, hardware, and tech maintenance in forward locations limits real-time inventory monitoring; high dependency on manual entries invest in robust ict infrastructure; use mobilecompatible logistics platforms lack of centralized training institutions defence industries report; repswal (2021) absence of a tri-service logistics training academy focused on modern scm non-uniform training standards; varying competence levels across services establish defense logistics and scm training academy with tri-service modules limited exposure to civilian scm practices total military insight (2024); panday (2019) military logistics personnel rarely collaborate with private sector scm experts missed learning opportunities; insular approach to inventory optimization facilitate exchange programs with civilian scm experts; joint workshops and seminars limited scenario-based training army training manuals; bhalla (2009) training lacks simulated war-game scenarios for logistics disruptions poor preparedness for crises or high-demand surge situations incorporate scenario planning and simulation exercises into logistics training the current level of information and communication technology (ict) infrastructure, along with decentralised training resources, presents opportunities for strategic enhancement [11], [27]. additionally, while the defense logistics environment is distinct in its structure and purpose, there is scope to explore adaptive practices from other sectors where applicable [20] [25]. overall, the observations suggest that a multi-dimensional approach integrating digital platforms such as erp and ai tools with skill development, structural alignment, and performance-oriented models may contribute positively to enhancing operational effectiveness [10] [36]. 5. conclusions this study, grounded in secondary data analysis, provides a synthesized view of the evolving landscape of supply chain management in the indian defense sector. the review highlights areas where existing logistics practices offer opportunities for further enhancement, particularly in inventory visibility, technological integration, and cross-agency coordination. while current systems are supported by established frameworks, there is considerable scope to strengthen responsiveness through the adoption of integrated digital tools such as dss vol. 6, no. 1, 2025, pp.39-48 46 erp platforms and ai-based planning systems. the analysis also suggests that the effectiveness of such advancements would be further supported by initiatives aimed at capacity building, standardization of processes, and inter-service alignment. as defense logistics continues to adapt to contemporary operational demands, a structured focus on modernization, policy alignment, and skill development will be instrumental in fostering a more agile and efficient supply chain ecosystem. 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[46] total military insight, "understanding indian armed forces logistics: a critical backbone," total military insight, 2024. microsoft word review of wireless sensor network security_almisreb (1) (online) issn 2744-1741 defense and security studies original research vol. 6, no. 1, 2025, pp.25-38 https://doi.org/10.37868/dss.v6.id278 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 25 review of wireless sensor network security jusuf elfarahati1*, tarik pašić1, emir kurtanović1, admir ferhatović1, ermin šabotić1, ali abd almisreb*1, 1 international university of sarajevo, bosnia and herzegovina *corresponding author e-mail: aalmisreb@ius.edu.ba received: jan. 3, 2025 revised: feb. 5, 2025 accepted: feb. 7, 2025 online: feb. 13, 2025 abstract this review explores the security challenges and solutions associated with wireless sensor networks (wsns). it provides a comprehensive analysis of common security threats, including various types of attacks and their potential impacts on wsns. the paper discusses critical security requirements such as data integrity, authentication, and secure communication, and examines defensive measures to mitigate these threats. additionally, the review addresses trust management within wsns, highlighting the importance of establishing reliable and secure networks. emerging trends such as the integration of artificial intelligence, blockchain technology, quantum cryptography, edge computing, and secure multi-party computation are also discussed, showcasing the latest advancements aimed at enhancing wsn security. the findings underscore the necessity for ongoing research and development to improve the security and efficiency of wsns, ensuring their viability for diverse applications. © the author 2025. published by arda. keywords: wireless security; communication; data integrity; authentication 1. introduction alongside the development of wireless networking comes the development of sensor nodes. by being small in size and low in price, sensor node networks represent an improvement over traditional sensors since they come with embedded processors and can exchange data with each other. they find themselves useful in many fields of human interest from civilian to military tasks and are becoming more and more popular. throughout this paper, we will try to present the advantages and disadvantages of wireless network sensors, explain their function and usability together with ways to make the network more secure and able to defend against outside attacks. low cost and versatility are the main characteristics of wireless sensor networks. they manage to solve a great deal of problems that require monitoring, recording, and organization of collected data into one centralized node. with the advancement of self-learning and self-maintainable systems, they also aim to become selforganized through algorithms and network protocols, which represent the core concepts of these networks [1]. the paradigm of wireless network sensors sounds very futuristic and innovative on paper, but in reality, it is extremely hard to accomplish and connect it all into a meaningful system. wireless network systems bring with dss vol. 6, no. 1, 2025, pp.25-38 26 them a great deal of security risks and are far from ideal systems. they lack power and data storage which are crucial to the traditional techniques that are used for security. in these disadvantages we see similarities with very old machines (low processing power) and the trend of cost reduction will do little to none to help solve the problems above, while on the other hand, the increasing cost would solve various issues that would render wireless networks useless from a business standpoint. another fatal security flow is communication channels which are often unreliable and operations that are ignored by the system and don’t contribute it, but still waste precious processing time [2]. engineers and scientists both are addressing issues from which these networks suffer [3]. their goal is the maximization of processing capabilities and reduction of power consumption together with the implementation of security systems. many different approaches to wireless sensor networking are being tested, some of which are: secure and efficient routing, data aggregation, group formation, and many more [2]. up until recently, many researchers who were pioneering in the field of wireless networking sensors took for granted that all of the nodes that the system consists of will just agree to work with each other and that every node is trustworthy. this proved to be another security flaw of these networking systems and in order to solve these problems researchers had to work on the development of a trust model. as we can clearly see from this introduction wireless network systems come with many problems, but are worth investing in. they can solve many problems at lower cost and more efficiency, but they require a great deal of investment and development. in the following paper, we will discuss obstacles to security, requirements of a secure network, attacks, and defensive systems of wireless network sensors. our literature was chosen from many different academic sources. all of it revolves around the usage of wireless sensor networks. alongside many book segments and articles, we have chosen a number of different surveys that have the role of confirming importance of the wireless sensor networks. for our paper, we used [1] as our main guideline since the topic at hand covers a vast area of human expertise and we found that [1] comprises many different papers, books, and surveys into a meaningful whole which helped us great deal with making of this paper 2. discussion 2.1. obstacles to security the system of wireless network sensors shares many similarities with older computer systems. old and new usually don’t fare well together and that is the case with these networks. trying to overcome the liabilities of a network and combine it with new technologies regarding security and resource management is difficult, but before trying to solve this problem, the first step should be understanding it. in order to provide authentication and data protection nodes must be aware of each other. they must establish communication between them and one of the solutions for the stated problem is public keys. since this part is about problem understanding we should focus more on the problem statement and constraints of the system. 2.1.1. ignored or unattended nodes when nodes of the system are left unattended they serve no purpose to the system and they can easily become liability. coming up with ways to deal with unattended nodes is extremely important, because we may face system failures because we are requesting some resource that we didn’t know wasn’t available. there are several scenarios in which a node can be left unattended:  physical damage – nodes are often faced with the danger of being physically damaged since they can be placed in various locations that are far away from the central node. this is not a liability with computer networks, because usually pcs are placed on secure locations and only worry about software attacks [4] [1].  remote management – in various scenarios nodes might be unavailable for maintenance. in such scenarios, if they suffer physical damage it is impossible to fix it. we must let go of the node. one of dss vol. 6, no. 1, 2025, pp.25-38 27 such example would be a node running out of battery while deep underwater where it cannot be reached, or suffering physical damage behind enemy lines [5].  decentralized architecture – the wireless sensor network should be a centralized system of connected nodes. they all should be connected to one central node. if that is not the case and nodes are managed in a decentralized fashion then the difficulty of organization, inefficiency, and unreliability of network rises [4]. we can conclude that we must find a way to handle unattended nodes. losing one node would not cost us financially, but if left ignored then new possibilities are opened for malicious attacks and we risk destabilization and security of the whole system. 2.1.2. unreliable communication communication between nodes is the most important feature of wireless sensor networks. it is strictly defined with network protocols. deciding which protocol should be used sets quality and security standards and capabilities of the system. without reliable communication systems will be easily overloaded with incomplete data which serves no purpose. unreliable communication is usually caused by the following:  incorrect protocol – using the wrong protocol can prove devastating. in wired network systems dividing data into packets and sending them separately proved to be extremely reliable, but when it comes to wireless sensors this transfer type becomes connectionless and unreliable. with connectionless packet transfer, we risk a high percentage of damaged or missing packages. furthermore, a protocol that we want to use must have extremely good error handling since we expect a higher rate of error with connectionless data transfer [6].  density – the density of the network affects communication between nodes. even with reliable channels if packets meet while traveling their collision will create disturbance and communication will fail. this happens due to the broadcast nature of wireless sensors.  latency – many factors can affect a difference in latency between nodes. different computation times and network congestion are examples of causes for the increase in latency. it becomes difficult to achieve synchronization of the system if latency stars vary. this becomes a huge problem in real-time systems [1]. 2.1.3. limited resources we are long past the time when our pcs could run out of resources when it comes to coding. if we go through some older codes it becomes clear that they didn’t care for their variable names. they usually make no sense and are represented with only a single letter. there is an actual reason that those variable names are so short and that is because there wasn’t enough memory to store larger strings. modern pcs allow us to write much more meaningful and beautiful codes, but wireless network sensors suffer from the same problem as older computers. they lack memory and because they are wireless they lack sufficient energy supply:  memory – sensors are physically small devices and more memory requires more space. every device comes with a small amount of memory and storage space for code. we can take for example one of the common sensor types, teslob which has: a 16-bit, 8 mhz risc cpu; 10k ram; 48k program memory, and 1024k flash storage. memory size dictates the size of software code, which we can easily assume is not much. when it comes to security in the case of teslob [1], we don’t have much space for the code and must be very careful and smart not to overload it with unnecessary code.  energy supply – same as memory, energy supply is limited with the size of the device. node lives while its battery has power in it. if we make an assumption that it is hard to replace batteries due to high maintenance cost, then ensuring long battery life becomes one of the most crucial tasks to deal with. power capacity of the node is so small that we must consider the impact of security code that we add to the node. functions that security systems usually use like encryption, decryption, signature verification, dss vol. 6, no. 1, 2025, pp.25-38 28 and similar, can cost these small devices lots of power. adding more security layers demands more power [2]. wireless sensor networks come with many obstacles to secure communication. in the discussion following this chapter, we will consider different solutions to the given problems. 2.2. security requirements a sensor network is a special kind of system. it imparts a few shared traits to a run of a typical computer network, yet in addition, presents special prerequisites of its own. along these lines, we can think about the necessities of a wireless sensor organization as including both the run-of-the-mill typical prerequisites and the unique prerequisites suited exclusively to wireless sensor networks. there are many aspects of security requirements when it comes to wireless sensor network security. some of them are: data privacy, data integrity, data freshness, availability, self-organization, time synchronization, secure localization, and authentication. of course, there are more than these mentioned aspects, but those mentioned will be explained in detail. 2.2.1. data privacy information privacy is the most vital issue in network security. each network with any security focus will commonly address this issue first. in sensor networks, privacy is identified with the accompanying [7]:  a sensor network ought not to spill sensor readings to its neighbors (in military applications, data can be very sensitive).  it is critical to construct a protected path in a wireless sensor network since in many applications, very sensitive data is being processed.  public sensor data (sensor personalities and open keys) ought to likewise be scrambled to some degree to ensure against traffic examination assaults.  the standard methodology for keeping sensitive information safe is to protect the information with a secret key that just proposed receivers have, in this way accomplishing privacy. 2.2.2. data integrity with the execution of privacy, an enemy might be not able to take data. be that as it may, this doesn't mean the information is sheltered. the adversary can change the information, in order to send the sensor arrange into confusion. for instance, a malevolent node may include a few parts or control the information inside a packet. this new packet would then be able to be sent to the first receiver. information loss or harm can even happen without the presence of a malignant node because of the cruel communication condition. in this way, information integrity guarantees that any obtained information has not been adjusted in travel. 2.2.3. data freshness regardless of whether privacy and information integrity are guaranteed, we additionally need to guarantee the freshness of each message. casually, information freshness recommends that the information is recent, and it guarantees that no old messages have been replayed. this necessity is particularly critical when there are sharedkey systems utilized in the structure. ordinarily, shared keys should be changed after some time. be that as it may, it sets aside time for new shared keys to be spread to the whole system. in this situation, it is simple for the adversary to utilize a replay attack. likewise, it is anything but difficult to disturb the typical work of the sensor, if the sensor is unconscious of the new key change time. to tackle this issue a nonce, or some other time-related counter, can be added into the packet to guarantee information freshness. 2.2.4. availability altering the conventional encryption algorithms to fit inside the wireless sensor network isn't free, and will present some additional expenses. a few methodologies adjust the code to reuse however much code as could dss vol. 6, no. 1, 2025, pp.25-38 29 be expected. a few methodologies attempt to make utilization of extra communication to accomplish a similar objective. in addition, a few methodologies drive strict restrictions on information access or propose an unsatisfactory plan (central point scheme) so as to rearrange the algorithm. but all these approaches weaken the availability of a sensor and sensor network because additional computation consumes additional energy (no more energy exists means data will no longer be available), additional communication also consumes more energy, and a single point failure will be introduced if using the central point scheme. the prerequisite of security influences the task of the network, as well as is profoundly critical in keeping up the accessibility of the entire network. 2.2.5. time synchronization most sensor network applications depend on some type of time synchronization. so as to conserve power, an individual sensor's radio might be killed for time-frames. moreover, sensors may wish to process the end-toend postponement of a packet as it goes between two pairwise sensors. an increasingly cooperative sensor network may require group synchronization for following applications, and so forth. what is proposed is a lot of secure synchronization protocols for sender-receiver (pairwise), multihop sender-recipient (for use when the combined hubs are not inside single-hop range), and group synchronization [8]. 2.2.6. self-organization a wireless sensor network is a commonly specially appointed system, which requires each sensor node to be autonomous and sufficiently adaptable to act self-organizing and self-mending as indicated by various circumstances. there is no settled infrastructure accessible with the end goal of network management in a sensor network. this intrinsic element conveys an incredible challenge to wireless sensor network security too. for instance, the elements of the entire network hinder the possibility of pre-establishment of a shared key between the base station and all sensors [9]. a few random key predistribution plans have been proposed with regard to symmetric encryption methods [10]. with regards to applying public key cryptography procedures in sensor networks, a productive component for public key distribution is essential too. similarly, disseminated sensor networks must self-organize to help multihop directing, they should likewise self-organize to lead key administration and build trust connection among sensors. in the event that self-organization is inadequate in a sensor network, the harm coming about because of an assault or even a risky condition might be devastating. 2.2.7. secure localization frequently, the utility of a sensor network will depend on its capacity to precisely and naturally find every sensor in the network. a sensor network organization intended to find shortcomings will require precise area data so as to pinpoint the area of an error. shockingly, an attacker can without much of a stretch control nonsecured area data by revealing false flag qualities, replaying signals, and so forth. a well-known technique regarding this issue is verifiable multilateration (vm). in multilateration, a device's position is precisely registered from a progression of known reference points. verified ranging and distance bounding are utilized to guarantee the precise area of a node. given distance bounding, an assaulting node can just increase its guaranteed distance from a reference point. notwithstanding, to guarantee location consistency, an assaulting node would likewise need to demonstrate that its distance from another reference point is shorter [11]. for large sensor networks, the spine (secure positioning for sensor networks) algorithm is used. it is a three-phase algorithm based on verifiable multilateration. serloc ‘s oddity is its decentralized, range-independent nature. serloc utilizes locators that transmit reference point data. it is expected that the locators are trusted and can't be imperiled. besides, every locator is expected to know its very own location. a sensor figures its location by tuning in for the reference point data sent by dss vol. 6, no. 1, 2025, pp.25-38 30 every locator. the reference points incorporate the locator's area. utilizing the majority of the beacons that a sensor node detects, a node calculates an approximate location dependent on the coordinates of the locators. utilizing a larger part vote scheme, the sensor at that point processes an overlapping antenna region. the last computed area is the "center of gravity" of the overlapping antenna region [12]. 2.2.8. authentication an adversary isn't simply restricted to adjusting the information packet. it can change the entire packet stream by infusing extra packets. so the recipient needs to guarantee that the information utilized in any decisionmaking process starts from the correct source. then again, while building the sensor network, authentication is vital for some administrative assignments. from the above-mentioned, we can see that message authentication is critical for some applications in sensor networks. casually, information authentication enables a recipient to confirm that the information truly is sent by the guaranteed sender. on account of two-party communication, information authentication can be accomplished through an absolutely symmetric system: the sender and the receiver share a secret key to compute the message authentication code (mac) of all conveyed information. an enhancement is proposed to the μtesla framework that utilizes broadcasting of the key chain responsibilities as opposed to μtesla's unicasting system [13]. they present a series of plans beginning with a straightforward pre-determination of key chains and lastly settling on a multi-level key chain method. the multi-level key chain scheme utilizes pre-determination and broadcasting to accomplish an adaptable key distribution system that is intended to be impervious to refusal of service assaults, including jamming. 2.3. attacks of course, we cannot talk about the security of networks and not mention the most common types of attacks used against these wireless-based connections. there are many ways in which an attacker may try to harm the effectiveness of the connection or to try to expose the packets that are sent between the nodes. when talking about this topic we must keep in mind that these networks do not and cannot have state-of-the-art security mostly because of two reasons. the first of them is that the nodes inside this network do not have that much computational power, which handicaps them from using heavy computational algorithms that provide more security. the second reason is that the nodes in these networks are usually exposed and reachable, their locations are usually known, for example inside of a traffic light if the network in question is used for traffic management or traffic information collection. in this part, we will explain the most used attacks on these networks. [14]. 2.3.1. denial of service attacks the first type of attack that we will address is denial of service attacks. these attacks are based on jamming a node or set of nodes. the jamming of a network can come in two forms: constant or intermittent jamming. constant jamming means the complete jamming of the entire network. no messages can be sent or received. however, if the jamming is only partial or intermittent, then nodes can exchange messages periodically, but not consistently. these attacks can be used on the link layer, routing layer, and even the transport layer. link layer attacks are based on breaking the protocol of the network (for example ieee 801.11b) and this will cause constant retransmissions which will deplete the power supply of the node. routing layer attacks use the fact that these networks use multi-hop to exchange messages and then an attacker can use their node to purposely route messages to wrong nodes. lastly, transport layer attacks are based on flooding a certain node. what this means is that the attacker sends too many connection requests to a node and the node allocates resources to handle these requests and if too many resources are allocated it is rendered useless [15]. 2.3.2. the sybil attack the sybil attack is defined as a “malicious device illegitimately taking on multiple identities” [16]. this attack is known for bypassing redundancy mechanisms of networks, routing algorithms, data aggregation, and fair dss vol. 6, no. 1, 2025, pp.25-38 31 resource allocation. the sybil algorithm utilizes multiple identities to generate false nodes or creates multiple false routes to render communication slow or impossible [17]. 2.3.3. traffic analysis attacks these attacks are like observations on a certain network so that the attacker can know “where to strike”. these attacks are founded on the principle that these networks usually have a base node that forwards packets more than the other nodes. there are certain algorithms that can define with a high probability of success, which node is a base node, and when the attacker knows this, he can actively try to jam or disable this node to weaken the performance or disable the network completely [18]. 2.3.4. node replication attacks the description of this type of attack is already given in the name. the attacker tries to imitate a node inside the network and by doing this he may infiltrate the network successfully. this can lead to many problems, for example, corrupted packets, false network readings, misrouting packets, and many more [19]. 2.3.5. physical attacks as previously stated, nodes in these networks are vulnerable to physical attacks since they are usually in an exposed place. this means that an attacker can use force to open the node and mess with the code and hardware inside. these attacks usually involve forcibly opening the sensor, deleting and then inserting modified code to do false instructions, get information, and more [20]. 2.4. defensive measures 2.4.1. key establishment using keys for encrypting and decrypting data is a common practice in all of computer science and related fields. wireless sensor networks are no exception to that. they are the foundation of securing networks in general and that is why i am going to start the defensive measures with concepts regarding key establishment. devices used in wireless sensor networks are of course specific and have specific characteristics of performance, energy, efficiency, and processing power. these are all attributes that need to be taken into consideration when trying to apply a key management technique. usually, the most secure and widely used way for key management is public key encryption algorithms. public key encryption is an asymmetric type of encryption. it works in the following way. two keys are generated which have a mathematical relation (the relation depends on the algorithm used). one of the keys is the public key and the other one is the private key. the public key can then safely be distributed to any external clients and these clients can then encrypt data using that key. data encrypted using the public key can then only be decrypted using a combination of the public and private keys, and the only owner of the private key is the source that gave out the public keys. there exist various algorithms for the public-private key generation and this method is extremely secure because it would take an unreal amount of processing power to crack the private key. currently, we lack that processing power. one of the most popular public key encryption cryptosystems is rsa (rivest-shamir-adleman) which is heavily used throughout the web and application network layer. but here comes the issue. as i mentioned earlier, devices in wireless sensor networks are specific in terms of power. to be cheap these devices lack computational power and public key encryption requires a lot of computational power when compared to these devices. that is why we often need to use the simpler, symmetric approach called shared key encryption. shared key encryption, as the name implies, works like this. you encrypt data using some encryption algorithm and some key, now to access this data a client needs the same key, so the key needs to be shared, hence the name. and it is symmetric because both sides need the same key. the most used algorithm for symmetric encryption is des (data encryption standard). one disadvantage is that the key is easier to crack and therefore dss vol. 6, no. 1, 2025, pp.25-38 32 it is less safe than other algorithms. but there are of course other algorithms for symmetric encryption, because as i said, they are computationally easier and suited for sensor devices, but still they all have one major problem, and that is that both hosts need the key to establish communication. the obvious problem with this is how to be sure that the two hosts that need to exchange data are legitimate and that no third party tried to be in the middle of it. now let us talk about proposed solutions to the mentioned problem. the first solution is proposed by eschenaur and gligor [21]. it is the idea of randomly pre-distributing key rings to nodes in a wireless sensor network [22]. each keyring is to contain a set of randomly chosen keys from a larger set of keys. although not a perfect solution, this way it is probabilistically very likely that each node would have another pair node sharing the same key from their respective keyrings and therefore would be able to establish a direct link. the idea is that this would make it possible for full-fledged communication in larger networks. the next solution is the leap protocol. its idea is to preload the nodes with a key. the nodes then use that key to establish a link generate a new key for communication and then delete the preloaded key. another protocol is the pike protocol, which introduces the idea of using a trusted third-party node for any two sensor nodes. the sensor nodes that need to communicate do not share the keys directly but share their key with the third-party node. the last idea for establishing a secure connection between nodes is to have a base station in the wireless sensor network. the base station should have more computational power and be able to do public key cryptography operations. then, the sensor nodes would communicate with the base station through some symmetric approach, but the base station would take care of public key cryptography for the sensor nodes when they communicate with each other. this is in my opinion the most secure way, but probably the most expensive too. it is important not to forget that public key encryption is not completely ruled out as a method of key management inside wireless sensor networks. there are cases where so-called ecc – elliptic curve cryptography can be used to secure a wireless sensor network. ecc is an asymmetric algorithm like rsa. the main difference is that ecc generates shorter keys than rsa, 160 compared to 1024 bits, and that is why ecc is more suited for sensor nodes than rsa. 2.4.2. defense against dos attacks dos (denial of service) attack is probably the most common type of attack on any network and on any network layer. in the case of wireless sensor networks, a couple of approaches can be used. let us start with the simplest one. the logical approach to a dos attack would be to find the jammed node and simply route around it [21]. the hard part here is to find out which node is the attacked one. proposals have been made for an algorithm where the nodes that are near the jammed one, report their status to their neighbors and then declare the jammed node as unavailable and construct new routes around it. the next approach is to handle the dos attack at the data-link layer by using mac addresses. the idea is to impose a rate limit for a sensor node to start ignoring resource-heavy requests. this approach has one issue though, there is no way to tell the difference between malicious intent and high-volume traffic. our next issue is malicious nodes that try to miscarry information. to overcome them we can simply send the same message over more routes and hope that at least one of the routes has no malicious node in it. this approach introduces of course redundancy but is simple and efficient. the last type of dos attack that we will talk about is the flood attack. flooding is a transport layer attack where so many requests are sent that the server cannot handle legitimate requests because it is out of resources. sometimes there is nothing you can do here, but some engineers have made a proposal to force clients to solve dss vol. 6, no. 1, 2025, pp.25-38 33 a puzzle given out by the server before entering communication. this puzzle is supposed to be computationally intensive to solve. this way a client would have always to commit resources before the server, thus rendering a dos attack impossible unless an unreal amount of resources is used. it is an interesting idea, at least. it reminds of how blockchain works, but i personally do not like it because it would slow down the communication between client and server. 2.4.3. combating traffic analysis attacks surely there are ways to defend against traffic analysis attacks. one of the most common combats is using a random walk forwarding technique, which sends packets from time to time to a node that is not the sensor’s parent node. but again, this does not cover the time correlation attacks. for this to be covered dent et al. suggest a fractal propagation strategy. using this strategy a node will generate a packet that is fake when its neighbor is forwarding a packet to the base station. this packet which is fake is sent to another neighbour who may also generate a packet that is also fake. there are several defense techniques with which to combat sensor attacks, they are listed below [23]. 2.4.4. anonymity mechanisms information about location which is described in detail can give the opportunity for an intruder to get user details or to track future user movements, this is a big problem and it presents a threat to a user. the mechanism is to depersonalize the data before they are released [24]. there are three approaches:  decentralize sensitive data – distribute data of location to a spanning tree.  secure communication channel – using spins protocol the active attacks can be prevented  change data traffic – inserting some extra clear data can change the traffic pattern  node mobility – changing node positions can defend against attacking privacy. 2.4.5. information flooding there are many proposed anti-traffic analysis mechanisms to defend against attackers from outside tracking the node locations since that would uncover the information about the location of sensed objects. [25] the methods that are used to defend against that are: the randomized data routing and phantom traffic generation mechanism. they are used to cover the real data traffic so that it is difficult for the attacker to track the data source by analyzing the traffic of the network. there are many methods for single-path routing which are trying to solve privacy problems. some of them are: baseline flooding, probabilistic flooding, flooding with fake messages, and phantom flooding. 2.4.6. intrusion detection there are many techniques that are used to prevent intruders from viewing the network data. knowing the importance of detecting intruders, there are still no good solutions for this. the two main categories of intrusion detection are: anomaly-based intrusion detection (aid), and misuse intrusion detection (mid) [26]. anomaly-based intrusion detection is a detection that assumes that the intruders will do something ambiguous to the legitimate nodes, so unusual system behavior will be present. while in misuse intrusion detection the whole system has a database of the intrusion signatures which can help the system to easily detect the intrusions. the intrusion detection in wireless sensor networks is all done with cryptography. intrusion detection can be divided into two categories: host-based and network-based. host-based ids systems are doing the combats related to operating systems audit trails, logs, system call audit trails, and so on. a network-based ids operates with packets that are captured from the network. dss vol. 6, no. 1, 2025, pp.25-38 34 figure 1. the lids architecture [2] 2.4.7. secure data aggregation as the amount of data the sensor networks are able to sense, the wsn continues to grow in size. because every sensor has constraints that are computational, a single sensor is responsible for a small part of the overall data. so this is the reason why the raw data is being returned from the wireless sensor network. it is the priority for the raw data to firstly be processed in order to have and fetch useful data from the network and it is done using many aggregators. the job of aggregators is to process the raw data into useful data collected from the subsets of nodes. however, this technique is vulnerable to attacks because one single node is just used to process and aggregate the data. there are many techniques used today in secure data aggregation. the localized algorithm uses the directed diffusion technique using only local nodes. using this technique the nodes that are at a higher level are able to communicate across clusters, while lower-level nodes are not able to communicate. we have one problem with the techniques which are the standard ones. the problem is that they assume that the nodes are trustworthy, which is not the case, so for that secure data aggregation techniques will be required. stealthy attacks are attacks where an intruder creates fake aggregation data which are represented to the user by providing the incorrect aggregation results without the user spotting it. so the goal is to make sure that the accepted aggregate value from the user has a high probability that the value is near true to one aggregation value. so the user has the option to reject or accept the aggregation value. this approach is called the aggregatecommit-prove technique. hu and evans gave a secure data aggregation technique that uses the (mi)tesla protocol for security. in the description of their technique, it is stated that the nodes are organized into a tree-based hierarchy where the internal nodes are aggregators [27]. it is not, however, guaranteed in this technique that all nodes and aggregators provide the correct values [23]. 2.4.8. defending against physical attacks physical attacks represent a great problem for wireless sensor networks because of their unattended features and limited resources. the physical hardware would help to enhance protection against many attacks from outside. to protect, for example, against tempering with the sensors, one defense involves tamper-proofing the node’s physical package. one possible way of protecting the sensor nodes with the physical hardware is self-termination. as the name tells us, the sensor destroys itself (including destroying all data and keys), when it spots a possible attack. this is specifically used in large wireless sensor networks where the cost is much cheaper for the sensors compared to the loss of being broken (attacked). the solution which seems the simplest one is periodically conducting neighborhood checking in static deployment. dss vol. 6, no. 1, 2025, pp.25-38 35 andersen et al. gave examples based on these attacks with low-cost protection:  randomized clock signal – inserting random-time delays  randomized multithreading – multithread processor architecture that schedules the processor by hardware between two or more threads of execution randomly at a per-instruction level.  restricted program counter – avoiding program counter which can traverse through the whole address space. 2.4.9. trust management trust is very important in any network environment, social networking, or computer networking. trust can be used in front of traditional cryptographic security. for example, if we want to know whether the sensor nodes and the quality of their services are of high quality, also whether the aggregator is performing aggregation as it should perform. finding of liang and shi focus on trust model development and the rating aggregation algorithms analysis in the untrusted environments that are open. their findings can be applied to wireless sensor networks. they found out that rating is not useful for always knowing the limitations of the other factors [21] [7]. 2.5. emerging trends in wireless sensor network security in recent years, the field of wireless sensor network (wsn) security has seen significant advancements driven by the increasing complexity and deployment of wsns in various critical applications. this section explores the latest trends and innovative approaches that are shaping the future of wsn security. 2.5.1. artificial intelligence and machine learning artificial intelligence (ai) and machine learning (ml) have emerged as powerful tools in enhancing the security of wsns. these technologies are being leveraged to develop intelligent intrusion detection systems (ids) that can identify and mitigate security threats in real-time. ai and ml algorithms can analyze vast amounts of data generated by sensor nodes to detect anomalies and predict potential attacks, thereby improving the overall resilience of wsns [28]. 2.5.2. blockchain technology blockchain technology is gaining traction as a means to secure wsns by providing a decentralized and tamperproof ledger for recording transactions and data exchanges. this technology ensures data integrity and authenticity, making it difficult for attackers to alter or forge information. blockchain can also facilitate secure key management and authentication processes within wsns [29]. 2.5.3. quantum cryptography quantum cryptography is an emerging field that promises to revolutionize wsn security by leveraging the principles of quantum mechanics. quantum key distribution (qkd) enables the secure exchange of cryptographic keys, ensuring that any attempt to intercept or tamper with the keys is detectable. this technology offers a high level of security that is theoretically immune to computational attacks [30]. 2.5.4. edge computing edge computing involves processing data closer to the source, i.e., at the edge of the network, rather than relying on centralized cloud servers. this approach reduces latency and enhances the security of wsns by minimizing the exposure of sensitive data to potential attacks during transmission. edge computing also enables real-time data analysis and decision-making, which is crucial for timely threat detection and response [31]. 2.5.5. secure multi-party computation secure multi-party computation (smpc) is a cryptographic technique that allows multiple parties to jointly compute a function over their inputs while keeping those inputs private. in the context of wsns, smpc can be dss vol. 6, no. 1, 2025, pp.25-38 36 used to perform secure data aggregation and analysis without revealing individual sensor data. this approach enhances privacy and security, particularly in applications involving sensitive information [32]. these emerging trends highlight the dynamic nature of wsn security and the continuous efforts to address the evolving threats and challenges. by integrating advanced technologies such as ai, blockchain, quantum cryptography, edge computing, and smpc, researchers and practitioners can develop more robust and resilient wsns capable of withstanding sophisticated cyber-attacks. 3. conclusions this paper provides a comprehensive review of the security challenges and solutions associated with wireless sensor networks (wsns). it outlines the most common attacks and the defensive measures required to protect wsns, covering topics such as obstacles to security, security requirements, attacks, defensive measures, and trust management. additionally, the paper explores emerging trends in wsn security, including the integration of artificial intelligence, blockchain technology, quantum cryptography, edge computing, and secure multi-party computation. these advancements highlight the dynamic nature of wsn security and the continuous efforts to address evolving threats. the findings underscore the necessity for ongoing research and development to enhance the security and efficiency of wsns, ensuring their viability for diverse applications. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] j.p. walters, z. 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[29] m.h. behiry, m. aly, "cyberattack detection in wireless sensor networks using a hybrid feature reduction technique with ai and machine learning methods", journal of big data, vol. 11, no. 1, 2024. [30] g. mohan ram, e. ilavarasan, "security challenges in wireless sensor network: current status and future trends", wireless personal communications, vol. 139, pp. 1173–1202, 2024. [31] y. ghadi, t. mazhar, t. al shloul, t. shahzad, u.a. salaria, a. ahmed, h. hamam, "machine learning solution for the security of wireless sensor network", ieee access, vol. 12 4, pp. 12699-12719, 2024. [32] a. akinsola, t.k. njoku, o. ejiofor, a. akinde, "enhancing data privacy in wireless sensor networks: investigating techniques and protocols to protect privacy of data transmitted over wireless sensor networks in critical applications of healthcare and national security," international journal of network security & its applications (ijnsa), vol.16, no.2, 2024. microsoft word 295_122-131.docx (online) issn 2744-1741 defense and security studies original research vol. 6, no. 2, 2025, pp.122-131 https://doi.org/10.37868/dss.v6.id295 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 122 vulnerability analysis of critical infrastructures with the event tree technique francesco trinchillo1* 1 independent researcher, naples, italy *corresponding author e-mail: francesco.trinchillo.1987@gmail.com received: nov. 4, 2025 revised: nov. 20, 2025 accepted: nov. 26, 2025 online: nov. 26, 2025 abstract the vulnerability analysis of a critical infrastructure is certainly a complex and articulated study; therefore, it requires the use of reliable decision support tools. in this article, after a brief review of the state of the art on risk analysis studies for critical infrastructures, a vulnerability analysis will be performed on a railway infrastructure under the hypothesis of an intentional attack by a criminal group. specifically, the aim of this paper is to show how the application of the event tree technique derived from the more well-known fault tree analysis can allow to define the different scenarios. for each one, a probabilistic assessment will be carried out through numerical simulations with the monte carlo method in order to calculate the security level of this infrastructure. © the author 2025. published by arda. keywords: critical infrastructure, vulnerability analysis, defense of the country, event tree technique, monte carlo method, railway system 1. introduction a critical infrastructure – according to the current european legislation – is defined as an element, a plant, a piece of equipment, a network, a system, or a part thereof necessary for the provision of an essential service. thus, protecting national critical infrastructures is necessary to guarantee the continuity of essential services, i.e., those that are fundamental for the maintenance of vital functions of society, economic activities, public health and safety, or the environment. the operation of critical infrastructures can be disrupted in the most varied ways that can range from a small inconvenience to total destruction; a natural catastrophic event (e.g., earthquakes, tsunamis, floods) or an indirect anthropogenic event (e.g., landslide, blackout), or a terrorist/criminal attack. the study of the vulnerability of critical infrastructures starts from their identification in order to define an appropriate level of protection that guarantees, for each typology, not only its conservation but also the maintenance of the supply of essential services, limiting the inconvenience for the population involved. the context of the operation of critical infrastructures has seen, during the years, a regulatory evolution [1]; now the critical infrastructures can be divided into 11 sectors: 1. energy 2. transport dss vol. 6, no. 2, 2025, pp.122-131 123 3. banking 4. financial market infrastructure 5. health 6. drinking water 7. waste water 8. digital infrastructure 9. public administration 10. space 11. production, processing, and distribution of food. it is clear, therefore, that the railway system of a european union country is classified as a critical infrastructure; indeed, also the first forms of regulation of the european commission drawn up at the beginning of the 2000s already include transport systems (roads, railways, ports, and airports) in the macro-categories of national critical infrastructures [1]. in the literature, there are several studies dedicated to the risk and vulnerability analysis of critical infrastructures, but only a few of these refer to the transport sector and specifically to railway systems. an interesting article [2] provides a complete and updated overview of the scientific research conducted, from 2008 to 2019, on the topic of railway resilience, showing a constant increase in the number of articles published in recent years. railway infrastructure is made up of many interconnected and interdependent elements; understandably, since in practice it is not possible to protect all elements of the system, the approach often chosen is to protect key elements. indeed, extensive research [3] aims to explore theoretical approaches to rail system vulnerability: identifying key elements can guide administrators in contributing to increasing resistance and in appropriately developing investments for the management and protection of railway system infrastructure. natural disasters, operational accidents, and terrorist attacks pose growing threats to railway systems, and their vulnerability and resilience have become major concerns for researchers and practitioners around the world. thus, the importance of transport resilience and the related concepts of risk and vulnerability are also addressed from the perspective of shocks that transport systems may experience, which can be internal or external, natural or man-made, intentional or involuntary [4]. in this context, a very interesting article 6 focuses on the resilience of rail freight operations in the event of extreme weather events. drawing on a british case study of rail network disruption following the closure of a key line in early 2016, the analysis considers the impacts on rail freight service provision and broader supply chains; the information provided is used to formulate a series of recommendations for the national rail sector. a recent study [5,6] analyzes the vulnerability and resilience of railway systems to disruptions from a conceptual, methodological, and practical perspective. it presents methodologies for assessing railway system vulnerability and resilience based on accessibility theory and examines the case study of the railway systems of two chinese cities, shanghai and shenzhen, using the proposed methodologies. another research [7] considers the emergency management of the transport of dangerous goods in the event of a terrorist attack by analyzing the evolution of the accident scenario using advanced georeferencing tools. 2. vulnerability analysis of the case study this article will conduct a risk analysis of the vulnerability of a critical railway infrastructure, starting from an event similar to a terrorist attack deliberately carried out with the aim of causing serious consequences to the infrastructure in question. this analysis is part of the broader discipline known as security risk, which studies the analysis of risks related to human actions aimed at producing catastrophic damage; one of the first studies on this topic [8] extends risk analysis methodologies to such incident scenarios, offering a methodology for the quantitative assessment of terrorism-related risks with the aim of supporting the decision-making process. dss vol. 6, no. 2, 2025, pp.122-131 124 an interesting study [9] focused very clearly on the analysis of business impacts and the quantification of different risks, in order to define the acceptable risk level/threshold. moreover, a recent research [10] has already considered similar critical infrastructures by adopting a time-based dependency risk analysis methodology, integrating and evaluating the effect of recovery controls. in that case, the proposed analysis methodology, based on awareness-based restoration, was integrated with a decision support system that enables the prediction of risk due to natural events to identify vulnerable and disrupted assets (e.g., electrical substations, telecommunications components). risk analysis methods are numerous and can be divided into two macro categories: qualitative and quantitative [11]; to determine the logic of attack sequences and consequently the reactions of security services/systems, more than one method can be used; among these, an inductive method called event tree analysis (eta) has been chosen, a methodology derived from the more well-known fault tree analysis technique, widely used in maintenance engineering [12]. the event tree technique can certainly be applied to intentional attacks (terrorist attacks, demonstrations, industrial sabotage, etc.); in this case, the event tree's final event is the achievement of a specific objective (damage, destruction, disruption of service, etc.), while the events that define the tree's structure are sabotage actions or actions by security personnel/police; each event is associated with a duration and probability of occurrence. this article aims to carry out an analysis that shows the possible vulnerabilities of a critical infrastructure, hypothesizing the various attack scenarios and quantifying in probabilistic terms the risk of their occurrence. consequently, useful insights can be gleaned into the "easiest" scenarios for attackers, thus defining the actual vulnerability level of the analyzed critical infrastructure. therefore, based on the results obtained, it will be possible to determine how to improve the security level, perhaps by introducing new systems designed to thwart attackers' actions or, at least, react in a timely manner and thus reduce the damage. 2.1. railway infrastructure the critical infrastructure under consideration is a railway electrical substation, a "node" connected to a highvoltage electrical grid capable of transforming and converting high voltage into a form suitable for powering train drives and motors. it is clear that the decommissioning of a substation will result in the failure of a section or even an entire railway line, resulting in the disruption of one of the country's essential services. furthermore, if the affected line is a high-speed/high-capacity line, the disruptions can be truly impactful for the country. typically, a railway substation is located immediately outside a residential area and in this case it is assumed to be within an area of approximately 2000 m2, which can be accessed through an automatic sliding steel gate overlooking a main road. the gate leads to a yard containing a building containing electronic equipment that controls the electrical energy conversion systems. outside, adjacent to the building, are the conversion and transformation systems, as shown in figure 1. figure 1. example of a railway electrical substation dss vol. 6, no. 2, 2025, pp.122-131 125 the area has a polygonal shape and is bordered on two sides by thick, tall vegetation that prevents the passage of vehicles and/or people; on the other sides, however, there are 3-meter-high metal fences topped with hooked gates. the area is equipped with a cctv system consisting of cameras, some fixed and some pan/tilt, positioned around the yard's perimeter and at the single entry/exit point, as well as those that monitor the entrances to the building housing the electronic equipment. the cameras are oriented so that the same point can be framed by multiple devices, and all are connected to the control room via a fiber optic backbone. the control room is located at the security department of the company that manages the country's railway network, while the nearest police patrol station is approximately 4 km from the substation. 2.2. attack scenarios and event tree construction this study hypothesizes an intentional attack by a criminal group aimed at damaging the electrical substation systems that power the transmission line for high-speed trains (tables 1 and 2). it is assumed that the group is already aware of the types of defense systems (active and passive) present and, specifically, knows the exact point to access to interrupt the fiber optic link that powers the cctv system. the possible scenarios envisioned for the case study in question all involve two sequences: one for the actual attack process, consisting of the criminal activities undertaken by the attackers; the second, however, is the sequence represented by the defense actions implemented first by the company security service and then by the police. both sequences, which then trigger the various scenarios, begin with the cutting of the fiber optic backbone, which causes the instantaneous deactivation of the cctv system; therefore, this action can be defined as the top event of the event tree, meaning it relates to an attack directed at a specific target. the duration of this action, although quantifiable as an average time, is deliberately excluded from the risk analysis because it is precisely by virtue of its identification as the top event, or initiator, from which the subsequent steps arise. in other words, if one were to hypothesize the introduction of the not operator for this event, the subsequent sequences would lose their meaning. table 1. average time for attack actions activity average time (minutes) reaching the substation 3 entry into the substation 8 reaching the equipment area 5 sabotaging the equipment 7 leaving the equipment area 2 leaving the substation and beginning the escapement 5 complete escapement 5 table 2. average time for defense actions activity time (minutes) security personnel interpret the situation 4 security personnel call the police 2 police action 22 the attack sequence can be summarized as follows: 1. reaching the substation 2. entry into the substation 3. reaching the equipment area 4. sabotaging the equipment 5. leaving the equipment area 6. leaving the substation and beginning the escapement 7. complete escapement dss vol. 6, no. 2, 2025, pp.122-131 126 the defense sequence can be summarized as follows: 1. security personnel interpret the situation. 2. security personnel call the police. 3. police action. for each activity, whether attacking or defending, an average time expressed in minutes has been identified. sequences can also be represented in the form of gantt charts (figs 2 and 3). figure 2. gantt chart with attack sequence figure 3. gantt chart with defense sequence to better contextualize the sequences just described, it is necessary to draw up hypotheses that allow us to properly define the event tree and understand the infrastructure's actual vulnerability level. specifically, we will assume that: • the cctv system was fully functional at the time of the attack. • the criminal group is informed of the nature of the cctv system and the location of the access point to the fiber optic backbone that powers it. • cutting the backbone will certainly deactivate the cctv system, but will also—with equal certainty—activate an alarm located at the company security guard post. • company security cannot intervene in the event of this type of attack and must request and await the intervention of the police. the success of the attack is confirmed by the sabotage of the equipment and the complete disappearance of the criminal group. this final event—which, as mentioned, corresponds to the complete success of the operation— can also be imagined as a consequence, involving the arrest of the group and, possibly, the prevention of the sabotage of the equipment. it is therefore assumed that police action could occur in the following phases: after exiting the substation but before the group has completely disappeared (scenario 2) after the sabotaged equipment has been removed from the area, but before exiting the substation (scenario 3) after the sabotage of the equipment but before reaching the exit (scenario 4) after reaching the area where the equipment to be sabotaged is located, but before its sabotage (scenario 5) after entering the substation but before reaching the area where the equipment to be sabotaged is located (scenario 6) it is clear that the event tree will foresee a total of 6 possible scenarios: the 5 just described in addition to the one that, obviously, foresees the success of the attack, which can be identified as scenario 1. for simplicity of discussion and based on the hypotheses made, it is assumed that reaching the substation and entering it (with the related break-in and tampering with the automation of the access gate) are certain actions, that is, that they occur with probability 1 and that the police cannot intervene before or during their execution; this allows us to limit the number of scenarios to those that are actually the most realistic. based on the above assumptions, it is possible to construct the event tree. (fig. 4). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 azione time to action [minutes] deactivation of cctv system reaching the substation entry into the substation reaching the equipment area leaving the equipment area sabotaging the equipment leaving the substation and beginning the escapement complete escapement 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 time to action [minutes] security personnel call the police police action security personnel interpret the situation azione dss vol. 6, no. 2, 2025, pp.122-131 127 figure 4. event tree with possible attack scenarios for simplicity, but without losing its meaning, it is assumed that both the corporate security service and the police cannot make significant errors in the execution of their tasks and that their interventions are 100% effective (meaning they completely block attack action) and are also detectable within an exact time frame. based on this further hypothesis, while the execution times of individual actions for the criminal group's activities remain variable, those relating to defensive actions become exact values. focusing on attack actions, the times of each of them can be considered random variables characterized by their own probability density distribution: for each action, therefore, the average time t already indicated in table 1 has been associated with a relative standard deviation σ, which, again for simplicity, is assumed equal to 30% of the average value. otherwise, based on the assumption made, the times of the defense actions (table 2) will be deterministic; therefore, we should not speak of mean time or standard deviation but only of action time. table 3. average time and standard deviation times for attack actions activity average time (minutes) standard deviation reaching the substation 3 0,9 entry into the substation 8 2,4 reaching the equipment area 5 1,5 sabotaging the equipment 7 2,1 leaving the equipment area 2 0,6 leaving the substation and beginning the escapement 5 1,5 complete escapement 5 1,5 table 4. exact time for defense actions activity time (minutes) security personnel interpret the situation 4 security personnel call the police 2 police action 22 2.3. probability calculation having defined the six possible attack scenarios, the next step is to understand the probability of one scenario occurring over another, in order to determine the actual level of vulnerability of the infrastructure. the solution to the presented problem begins by defining the total time required to complete the generic attack sequence, which will undoubtedly be the sum of the completion times for each criminal activity. ac ti vi ty d ea ct iv at io n of c ct v sy st em se cu rit y pe rs on ne l in te rp re t t he s itu at io n se cu rit y pe rs on ne l ca ll th e po lic e re ac hi ng th e su bs ta tio n en tr y in to th e su bs ta tio n re ac hi ng th e eq ui pm en t a re a sa bo ta gi ng th e eq ui pm en t le av in g th e eq ui pm en t a re a le av in g th e su bs ta tio n an d be gi nn in g th e es ca pe m en t co m pl et e es ca pe m en t scenario number scenario yes yes yes yes yes yes yes yes yes to p ev en t not not not po lic e ac tio n po lic e ac tio n po lic e ac tio n po lic e ac tio n po lic e ac tio n not not attack successful scenario 1 group arrest scenario 2 yes group arrest scenario 3 yes group arrest scenario 4 yes group arrest and sabotage prevented scenario 5 yes group arrest and sabotage prevented scenario 6 yes dss vol. 6, no. 2, 2025, pp.122-131 128 thus, indicating the total time for the generic scenario as tsi , we have: tsi = ta1 + ta2 + ta3 +… + tan table 5. average time for each attack scenario scenario average time (minutes) scenario 1 (attack successful) 35 scenario 2 (group arrest) 30 scenario 3 (group arrest) 25 scenario 4 (group arrest) 23 scenario 5 (group arrest and sabotage prevented) 16 scenario 6 (group arrest and sabotage prevented) 11 as already mentioned, however, the times of the individual attack actions are random variables, meaning they can assume different values each time one approaches the resolution of the problem under analysis. they are characterized by their own probability density function, which, for events of this type, can be considered lognormal. therefore, the total time of each scenario will also be a random variable whose probability density can be determined from the times of the individual activities. by applying the variable transformation method [13], it is possible to calculate the probability density associated with the generic scenario. the application of this methodology allows closed-form analytical solutions only for particular cases, that is, for those cases in which the probability densities are normal. in general, however, to obtain the solution, it is necessary to resort to numerical methods or monte carlo simulation. for the case study in question, the solution to the problem is obtained in two steps: the first objective is to calculate the probability of success of the attack (scenario 1), that is, to calculate the probability with which the total time required to carry out the entire attack sequence is less than the intervention time of the police: p attack successful = p (total time of attack sequence < time for police action) the second part of the problem consists in determining the probability of occurrence of all the other scenarios (from 2 to 6) that foresee the failure of the attack and therefore the arrest of the group due to the intervention of the police before the complete disappearance of the attackers; for these cases, the probability of occurrence can be determined as follows: p scenario i = [1 p (total time of attack sequence i < time for police action)], for i = 2 to 6 applying the monte carlo method leads to the solution shown in table 6. table 6. average time and probability of occurrence for each attack scenario scenario average time (minutes) probability of occurrence scenario 1 (attack successful) 35 0,332 scenario 2 (group arrest) 30 0,668 scenario 3 (group arrest) 25 0,357 scenario 4 (group arrest) 23 0,234 scenario 5 (group arrest and sabotage prevented) 16 0,153 scenario 6 (group arrest and sabotage prevented) 11 0,001 reporting the values in the event tree allows us to gain a more systematic view of the case study, as shown in fig. 5. dss vol. 6, no. 2, 2025, pp.122-131 129 figure 5. event tree with possible attack scenarios and probability of occurrence 3. results analysis the risk analysis conducted on this case study demonstrates how the event tree technique is able to provide a clear and systematic view of the problem. specifically, it is shown that, based on the assumptions made, the complete success of the attack occurs with a probability of approximately 33%. this provides an objective measure of the vulnerability of the critical infrastructure considered. however, there are five alternative scenarios, all of which involve the failure of the attack with the arrest of the group, and between these two, even the prevention of the sabotage of the equipment. in figure 6, the graph shows the trend in the probability of occurrence of each of the scenarios. the success of the attack (scenario 1) is not the most likely scenario; in fact, its alternative (scenario 2) consisting of the complete evolution of the criminal action but characterized by police intervention immediately before the escape is the most likely scenario, with a probability of occurrence around 67%. the other hypothesized scenarios, obviously, have a decreasing probability of occurrence; this is because the probability of the police intervening quickly is low. it is interesting to note that the probability of the attack's complete success is almost equivalent to scenario 3, which involves the group being arrested before leaving the substation; this highlights that, based on the protection systems in place, the final outcome is quite uncertain. figure 6. trend of the probability of occurrence for each scenario ac ti vi ty d ea ct iv at io n of c ct v sy st em se cu rit y pe rs on ne l in te rp re t t he si tu at io n se cu rit y pe rs on ne l ca ll th e po lic e re ac hi ng th e su bs ta tio n en tr y in to th e su bs ta tio n re ac hi ng th e eq ui pm en t a re a sa bo ta gi ng th e eq ui pm en t le av in g th e eq ui pm en t a re a le av in g th e su bs ta tio n an d be gi nn in g th e es ca pe m en t co m pl et e es ca pe m en t scenario number scenario probability scenario yes 1 yes 1 yes 1 yes 1 yes 0,999 yes 0,847 yes 0,766 yes 0,643 yes 0,332 attack successful 0,001 group arrest and sabotage prevented scenario 6 yes 0,001 group arrest and sabotage prevented scenario 5 0,153 yes 0,153 group arrest scenario 4 0,234 yes 0,234 group arrest scenario 2 0,668 yes 0,668 group arrest scenario 3 0,357 yes 0,357 scenario 1 0,332 to p ev en t not not not not not po lic e ac tio n po lic e ac tio n po lic e ac tio n po lic e ac tio n po lic e ac tio n dss vol. 6, no. 2, 2025, pp.122-131 130 4. conclusions this article conducted a vulnerability analysis for a critical infrastructure within the railway system of a european union country. specifically, it considered an electrical substation that supplies power to a high-speed train line. a power outage would lead to a halt in rail traffic, with significant impacts on transportation and, consequently, the national economy. a deliberate attack by a criminal group was hypothesized, characterized by successive actions that corresponded to corresponding reactions from existing security systems or the intervention of the police, with the aim of preventing sabotage of the equipment or, at least, arresting the criminal group. the case study, although linear and not complex in its outline, is extremely realistic and sufficiently comprehensive to maintain its generality. the event tree technique allowed us to identify the evolutionary path of the hypothesized dangerous condition, thus obtaining a clear attack sequence that, as previously mentioned, could be accompanied by responses aimed at reducing the damage. unfortunately, however, the method does not allow for exact solutions in terms of the probability of occurrence of each scenario, so a computational analysis using the monte carlo method was used. the application of the numerical method allowed for tangible results, enabling the definition of the most likely scenario and the prioritization of risks. this allows for the development of strategies aimed at preventing such actions, using resources (financing, labor, time, etc.) that can improve both passive (alarm systems, gates, etc.) and active (police action) security systems. an important aspect that this article aims to highlight is that vulnerability analysis is essentially independent of the causes of the attack (terrorist attack, demonstration, industrial sabotage, etc.). what matters is the attack's evolution and its modalities, in order to understand how to intervene to limit the damage or even prevent the attack. the purposes of this sabotage can be extremely varied, from a terrorist attack to a demonstration, but this is completely beyond the scope of this analysis. for this reason, the article will not address the hypothetical causes that could drive this criminal group to carry out such an attack. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] f. trinchillo, “critical infrastructures: european context and evolution of the law”, journal of defense resources management, vol. 16, pp. 319-330, 2025, doi:10.64404/jodrm.2025.1.15 [2] n. bešinović, “resilience in railway transport systems: a literature review and research agenda”, transport reviews, vol. 40, pp. 457-478, 2020, doi.org/10.1080/01441647.2020.1728419 [3] z. urbancová, e. sventeková, “assessing vulnerability of key elements of railway infrastructures”, transportation research procedia, vol. 40, pp. 1597-1603, 2019, doi.org/10.1016/j.trpro.2019.07.221 [4] e. jenelius, l. g. mattson, “resilience of transport systems”, in book international encyclopedia of transportation, pp. 258-267, 2021, doi:10.1016/b978-0-08-102671-7.10719-5 [5] a. woodburn, “rail network resilience and operational responsiveness during unplanned disruption: a rail freight case study”, journal of transport geography, vol. 77, pp. 59-69, 2019, doi.org/10.1016/j.jtrangeo.2019.04.006 [6] l. qing-chang, x. pengcheng et al, “railway vulnerability and resilience”, in book rail infrastructure resilience, woodhead publishing series in civil and structural engineering, pp. 5-35, 2022, doi.org/10.1016/b978-0-12-821042-0.00020-4 dss vol. 6, no. 2, 2025, pp.122-131 131 [7] f. m. milazzo, g. ancione et al, “risk management of terrorist attacks in the transport of hazardous materials using dynamic geoevents”, journal of loss prevention in the process industries, vol. 22, pp. 625633, 2009, doi.org/10.1016/j.jlp.2009.02.014 [8] j. b. garrick, j. e. hall et al, “confronting the risks of terrorism: making the right decisions”, reliability engineering & system safety, vol. 86, pp. 129-176, 2004, doi.org/10.1016/j.ress.2004.04.003 [9] d. pleskonjic, f. virtuani, o. zoggia, “security risk management for critical infrastructures”, 8th conference of the italian chapter of ais, rome (italy), 7-8 october 2011, doi:10.13140/2.1.3846.8800 [10] g. stergiopoulos, p. kotzanikolaou et al, “time-based critical infrastructure dependency analysis for largescale and cross-sectoral failures”, international journal of critical infrastructure protection, vol. 12, pp. 46-60, 2016, doi.org/10.1016/j.ijcip.2015.12.002 [11] d. c. simmons, r. dauwe et al., “qualitative and quantitative approaches to risk 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[online]. available: https://drmkc.jrc.ec.europa.eu/portals/0/knowledge/sciencefordrm/ch02/ch02.pdf [12] j. a. b. geymayr, n. f. f. ebecken, “fault-tree analysis: a knowledge-engineering approach”, ieee transactions on reliability, vol. 44, pp. 37-45, 1995, doi: 10.1109/24.376519 [13] l. fabbris, statistica multivariata: analisi esplorativa dei dati, mcgraw-hill libri italia, 1997. isbn 9788838607653. microsoft word 84-107_273 (online) issn 2744-1741 defense and security studies original research vol. 5, no. 2, 2024, pp. 84-107 https://doi.org/10.37868/dss.v5.id273 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 84 research on the problem of landmines and explosive remnants of war worldwide and methods of demining dženan ćosić*, alan ćatović2 1 department of product design, academy of fine arts, university of sarajevo, bosnia and herzegovina 2 defense technologies department, mechanical engineering faculty, university of sarajevo, bosnia and herzegovina *corresponding author e-mail: cosicdzenan49@mail.com received: sep. 3, 2024 revised: oct. 29, 2024 accepted: nov. 20, 2024 online: nov. 25, 2024 abstract the study addresses the global issue of landmines, with a particular focus on the challenges in bosnia and herzegovina. the research is grounded in precise data and facts from institutions and accredited demining organizations. the study further concentrates on innovative and highly effective detection methods, specifically for areas with challenging topography like bosnia and herzegovina, concluding with an innovative application of gpr and lidar radar technologies. additionally, it explores the most effective method for mine removal, and mechanical demining, providing a detailed overview of the operation and characteristics associated with this approach. conclusively, the study proposes the most efficient solution: a combined system of flails and tillers that alternately complement each other to achieve complete mine clearance. © the author 2024. published by arda. keywords: landmine, ugv (unmanned ground vehicle), mechanical demining, landmine detection system, lidar, gpr (ground penetrating radar), flail wheel, tiller 1. introduction the persistent global threat of landmines and unexploded ordnance (uxo) poses severe risks to civilians, economic stability, and post-conflict recovery efforts, with bosnia and herzegovina representing one of the most heavily mined regions in the world. various types of landmines, including anti-personnel and anti-tank mines, present unique challenges for detection and clearance. anti-personnel mines, particularly blast, fragmentation, and directional fragmentation types, are often designed to target individuals, while anti-tank mines are engineered to withstand greater pressure and pose a substantial hazard to vehicles and machinery. modern advancements in detection technologies, such as ground-penetrating radar (gpr) and lidar, offer enhanced capabilities in identifying buried mines with high accuracy, helping to reduce manual intervention risks. mechanical demining methods, which integrate tools like flails and tillers, have proven highly effective in physically neutralizing mines, offering versatility in different terrains. the innovative combination of flails and tillers within a single demining system capitalizes on the strengths of both tools, achieving increased clearance depth, efficiency, and adaptability to various soil types. this comprehensive approach to demining, combining advanced detection technologies with robust mechanical solutions, addresses the complexities of mine clearance, offering safer, more reliable solutions for global and localized demining efforts. 2. landmine threat according to united nations data, there are currently over 100 million landmines planted in more than 85 countries worldwide, with the vast majority laid within the past 80 years. most of these mines are anti dss vol. 5, no. 2, 2024, pp. 84-107 85 personnel mines, resulting in 15,000 to 20,000 casualties annually, with a mortality rate exceeding 50% due to the lack of immediate adequate assistance. the twelve most landmine-contaminated countries in the world, according to the united nations (un), are afghanistan, angola, bosnia and herzegovina, cambodia, croatia, eritrea, iraq, mozambique, namibia, somalia, nicaragua, and sudan. together, these countries account for more than 50% of the world’s contaminated minefields [1]. 2.1. the problem of landmines in the world global conflicts during the 20th century and the first half of the 21st century have left behind one of the most lethal weapons of all time: landmines. these mines represent the most inhumane and indiscriminate method of killing. for over 80 years, countries worldwide have been contaminated with unexploded landmines and ordnance. the development of these devices has continually advanced, making them even deadlier—even during the removal and demining processes. originally, landmines were created for offensive warfare, intended to prevent enemy reentry or to protect specific locations or fortifications. early forms date back to antiquity, with significant advancements in offensive warfare emerging with the discovery of gunpowder and its deadly applications. over the years, through successive wars, landmines have evolved to become increasingly lethal and resilient, purposefully designed with one goal: to kill. they have reached a level of resilience that even natural conditions do not affect their lifecycle; they are engineered to remain dangerous and deadly until they make contact with a person. more than 85 countries around the world are affected by the problem of landmines, posing a significant risk to the daily safety of civilians and innocent people who are at risk of becoming victims each day. 2.2. the problem of landmines in bosnia and herzegovina nearly 30 years after the end of armed conflicts, bosnia and herzegovina remains among the countries facing a significant landmine threat. landmines and unexploded ordnance (uxo) still pose a grave danger to the population and impede access to numerous resources. the conflicts on bosnian territory from 1992 to 1995 resulted in extensive mine-contaminated areas, making it difficult to estimate the exact number of mines laid or remaining. this challenge is due to incomplete documentation from various military and paramilitary organizations active during the war, with some records lost or destroyed in military operations. according to estimates by unicef, mac, and the u.s. department of state dating back to 1996, between 1,000,000 and 6,000,000 mines were placed on bosnian territory. this figure includes mines planted by military and paramilitary formations, as well as international forces operating in bosnia and herzegovina during that period. from 1996 to 2002, a total of 18,228 incidents were registered, with more than two-thirds occurring in the federation of bosnia and herzegovina. estimates by bhmac (bosnia and herzegovina mine action centre) indicate that suspected minecontaminated area was 4,000.2 km² (8.2% of the total land area). according to bhmac data as of december 31, 2021, the size of mine-contaminated or suspected hazardous areas across bosnia and herzegovina stands at 922.37 km² (1.8% of the total land area), with the federation of bosnia and herzegovina being more heavily affected, covering 727.28 km² (78% of the total contaminated area in the country). figure 1. landmine map of bosnia and herzegovina [5] dss vol. 5, no. 2, 2024, pp. 84-107 86 2.3. statistics of “hidden killers” although these "hidden killers" have evolved, their continued development—despite prohibitions and conventions—conveys the same fundamental message. the solution for countries affected by minecontaminated areas is to eliminate these dangers and make them safer through mine action programs, which increase awareness of the threat, remove the hazards, and provide holistic support to victims and their families. the understanding of landmine issues today is much more advanced than it was in 1993 or 1996 when the landmine ban convention was established. the problem of mine contamination is now viewed not only in terms of the numbers planted but also as an issue impacting many facets of daily life, including human safety and economic viability, due to the unusable nature of contaminated land. key points regarding demining:  efficiency of demining: this remains a persistent challenge, nearly insurmountable compared to the volume of mines laid. demining is estimated to take one hundred times longer than the placement of mines.  global mine count: over 100 million anti-personnel mines are laid worldwide.  estimated cost: more than $33 billion is needed to clear these mines (assuming no new mines are laid).  timeframe: at the current removal rate, it would take 100 years to clear all mines.  casualties: anti-personnel mines cause approximately 70 casualties per day, around 20,000 per year.  impact on children: over 300,000 children have been harmed by mines.  mortality rate: more than 50% of mine victims die en route to the hospital.  demining vs. laying mines: for every hour spent laying mines, 100 hours are needed for removal.  cost disparity: producing a mine costs as little as $3, but it takes more than $1,000 to remove.  risk of demining: the demining process is extremely dangerous, with one accident occurring for every 1,000 to 2,000 mines removed. 2.4. ban of landmines reports by the landmine monitor, un, and gichd describe anti-personnel mines as a “widespread” and long-term environmental contaminant and a significant driver of mortality rates. anti-personnel mines lack self-destruct mechanisms, endangering millions of lives daily. these are the primary reasons behind the ban on their production and use. in ottawa in 1997, an international treaty known as the "convention on the prohibition of the use, stockpiling, production and transfer of anti-personnel mines and on their destruction" was inaugurated, with 122 countries initially signing on. this convention placed anti-personnel mines on the list of banned weapons under international humanitarian law, aligning them with other weapons of mass destruction, such as biological and chemical weapons (war gases). since then, 164 nations worldwide have ratified or joined the convention, including the vast majority of countries affected by anti-personnel mines. bosnia and herzegovina has been a signatory to the ottawa convention since march 1, 1999. through domestic mobilization and increased international support, bosnia and herzegovina has destroyed its entire stockpile of anti-personnel mines, made significant progress in clearing mine-contaminated areas, and provided substantial support to victims from 1999 to the present. 3. classification of landmines a mine is an explosive weapon concealed below or camouflaged on the ground, designed to destroy or disable enemy targets, ranging from combatants to vehicles and tanks, as they pass over or near it. mines are primarily classified into: 1. anti-personnel mines (ap) 2. anti-tank mines (at) mines can also be classified by their activation mechanisms: 1. pressure-activated mines (triggered by pressure) dss vol. 5, no. 2, 2024, pp. 84-107 87 2. mines with alternative detonation mechanisms (such as tripwires, electrical circuits, or electronic fuzes) [1]. due to the structure of this work, we will limit our focus to the basic classification of mines, which also includes various types of mines that are detonated through different mechanisms. 3.1. anti-personnel mines anti-personnel mines are a type of pressure-activated mines designed for use against people, unlike anti-tank mines, which are intended for vehicles. they are often engineered to injure rather than kill victims, thereby increasing the logistical (mainly medical) support needed by the enemy forces encountering them. some types of anti-personnel mines can also damage the treads of armored vehicles or tires on wheeled vehicles. these mines are deployed similarly to anti-tank mines, in static “minefields” along national borders or to defend strategic locations. however, they differ from most anti-tank mines in their smaller size, allowing large numbers to be deployed over extensive areas. this deployment can be done manually, via dispensers on ground vehicles, or from helicopters or planes. alternatively, they may be scattered using specialized projectiles [1]. anti-personnel mines can be classified as follows: 1. anti-personnel pressure mines – activated by shockwave overpressure. 2. anti-personnel fragmentation mines – fragmenting upon activation. 3. anti-personnel directional fragmentation mines – designed for targeted dispersal. 3.1.1 anti-personnel blast mines (shockwave pressure effect) when a person steps on a landmine and activates it, the mine’s main charge detonates, creating a shockwave of hot gases traveling at extremely high velocity. this shockwave generates immense upward pressure, propelling the mine casing and any overlying soil upwards. upon impact, the shockwave transfers this force to the victim’s footwear and foot. this results in a significant compressive force on the victim’s foot, with the blast often causing severe injury or amputation. injuries vary depending on the main charge size, mine depth, soil type, and the manner of contact (e.g., full or partial foot placement on the mine). different soil types transmit varying energy amounts upwards; saturated clay-like soil, for example, transmits more energy. higher explosive charges release substantially more energy, extending the shockwave impact up the leg, sometimes causing traumatic amputation as high as the knee. secondary injuries are often from materials displaced by the explosion, including soil, stones, footwear fragments, and foot bone shards, which create additional wounds similar to other explosive fragmentation effects. special footwear, such as combat boots or "demining boots," provides only limited protection from the destructive force of mines, with foot loss being a typical outcome [3]. figure 2. type of anti-personnel (blast) mine; model vs-50 3.1.2 anti-personnel fragmentation mines while anti-personnel mines are designed to cause severe bodily injury, often leading to surgical amputations of the lower limbs, fragmentation mines are intended to disperse fragments over a broad area, primarily causing shrapnel injuries. these mines are typically larger and heavier than anti-personnel mines, as they contain a substantial metal casing (weighing several kilograms) that produces the fragments. one advantage of these mines is that they are relatively easy to detect due to their high metal content though this only applies in areas where the soil is not overly contaminated with iron materials or other metal waste. dss vol. 5, no. 2, 2024, pp. 84-107 88 figure 3. type of anti-personnel (fragmenting) mine; model: pmr-3 fragmentation mines are more effective and lethal on the battlefield due to their broader impact radius, with the potential to wound multiple individuals simultaneously. fragments from these mines can also partially disable armored vehicles by damaging suspension systems and tires, and in unarmored vehicles, they can significantly harm internal components and occupants. 3.1.3 anti-personnel directional fragmenting mines these mines differ from other types in that they are designed to direct their fragments in a limited arc. they are positioned so that the explosion is aimed toward a target area, away from friendly forces. this design allows forces to protect themselves by placing these types of mines near their own positions, but oriented toward the enemy. they are typically triggered in a conventional manner, either by a tripwire or through command detonation [4]. 3.2. anti-tank mines unlike anti-personnel mines, anti-tank mines typically contain a larger amount of explosive charge, making them exceptionally lethal. their primary purpose is to destroy or damage tanks or armored combat vehicles. the fuse design is specialized to activate only upon contact with a vehicle, by remote access from a monitored distance, or if there is an attempt to tamper with the mine for removal. the first anti-tank mines appeared toward the end of world war i as a countermeasure to british tanks. these initial forms were quite primitive; however, anti-tank mines saw significant expansion and development during world war ii, where their effectiveness on the battlefield led to the formation of the first demining units within armies, spurring mutual study among opposing forces. the most heavily contaminated anti-tank minefield recorded to date was on the eastern front in world war ii by the soviet army, reporting a total of 503,663 anti-tank mines, with an average density of 1,500 mines per kilometer. with the advancement of the global military industry, we now distinguish several types of anti-tank mines: 1. anti-tank blast mine based on the impact of shockwave overpressure. 2. anti-tank shaped charge mine (with explosively formed projectile efp). 3.2.1 anti-tank blast mine (based on shockwave effects) anti-tank blast mines, or mines activated by shock waves, function and are triggered similarly to antipersonnel blast mines. the key differences lie in the amount of explosive charge and the activation mechanism. anti-tank blast mines typically contain between 4 and 11 kg of various explosive charges, and the dss vol. 5, no. 2, 2024, pp. 84-107 89 pressure needed to trigger them is much higher generally, a weight over 100 kg is required. these mines are primarily intended to target and destroy vehicles, whether armored or unarmored, although certain variants can be triggered by human activity, especially during mine removal or demining processes. it is rare to find cases where one anti-tank mine is placed directly above or next to another to increase explosive power and lethality. they are designed to be placed precisely along the width of a tank’s track or the wheelbase of an (un)armored vehicle [1]. figure 4. anti-tank destructive mine; model tm-46 3.2.2 anti-tank shaped charge mine (based on explosively formed projectile) an explosively formed penetrator (efp), also known as an explosively formed projectile, is a specialized type of shaped charge designed to effectively penetrate armor from a much greater distance. as its name suggests, the explosive charge deforms a metal plate into a rod-like shape and propels it toward the target at high velocity. originally developed in the 1930s by american oil companies as perforators for oil wells, efps were later adapted for military use during world war ii. figure 5. anti-tank mine based on efp; model tmrp-6 3.3. unexploded ordnance (uxo) unexploded ordnance (uxo) is a term used to describe explosive devices that were prepared for use in armed conflict. this includes munitions that may have been fired, dropped, or launched but failed to detonate— military terminology refers to this as "unexploded ordnance." it is often abbreviated as "uxo," "nus" (from the bosnian term "neeksplodirana ubojna sredstva"), or "erw" (which stands for explosive remnants of war). dss vol. 5, no. 2, 2024, pp. 84-107 90 uxo is not exclusively linked to conflict zones from world war i and world war ii; areas such as military training centers, weapons production sites, and bombing ranges can also contain significant quantities of explosive ordnance buried underground or submerged underwater—even on coastal cliffs. uxo also refers to explosive devices that were never used during armed conflict and have been left behind or discarded. when explosive devices are discovered, they are sometimes destroyed in controlled explosions, although accidental detonations can also occur [6]. unexploded ordnance (uxo) contains unstable compounds that become increasingly sensitive over time due to aging. the expert advice is that if you ever encounter a suspicious object, do not touch it; instead, call the police or specialist services for assistance. the most obvious danger of encountering uxo is an explosion. however, some items dating back to world war i may have been associated with chemical weapons, and if they have been buried and left undisturbed for a long time, they could potentially cause environmental or soil contamination. the size or shape of any uxo does not indicate its potential danger; small objects can kill and maim if handled improperly it's better to be safe and take the appropriate precautions. as with most things, there are many exceptions to the rule, but generally, uxo can be categorized into two main groups [10,11,12]: 1. air-delivered explosive ordnance. 2. military explosive ordnance (items that have been fired, lost, dropped, buried, burned, or otherwise disposed of). essentially, unexploded ordnance is primarily classified based on its mass and the quantity of explosive filling: 1. small unexploded ordnance. 2. medium-sized unexploded ordnance (such as artillery munitions). 3. large mass unexploded ordnance (explosive devices with a filling mass of up to and exceeding 500 kg; e.g., aerial bombs). 3.3.1 small-size unexploded ordnance small unexploded ordnance (uxo) is one of the most prevalent forms of uxo found on battlefields worldwide, with estimates suggesting that over 65% of contaminated areas are comprised of this type. the contamination from this type of uxo is primarily due to its usability on the battlefield, where a significant number are left behind or lost, thereby becoming increasingly dangerous over time. these are defined as explosive devices with a small amount of explosive filling and smaller physical dimensions. they contain explosive filling of less than 500 grams and rely on a combination of explosive and fragmentation effects to incapacitate personnel and vehicles. examples include the following: hand grenades, mortar projectiles, 40mm anti-aircraft ammunition, and cluster munitions. figure 6. example of small-size uxo dss vol. 5, no. 2, 2024, pp. 84-107 91 3.3.2 unexploded ordnance of medium size medium-sized uxo is the second most common type of uxo, involving explosive devices with charges ranging from 1 to 20 kg. these devices rely on a combination of fragmentation and explosive effects to disable vehicles and personnel. this category includes certain types of projectiles, artillery shells, and smaller rockets. these explosives are typically encased in metal shells, making them particularly hazardous if left on the ground unexploded, where they pose a threat if accidentally encountered. exposure to moisture leads to metal oxidation and corrosion, which can make them even more deadly if disturbed or moved from their original position. the standard method for removing uxo of this type is to destroy it in a controlled manner at a safe location under supervised conditions. figure 7. example of medium size uxo 3.3.3 unexploded ordnance of large mass large-mass uxo is one of the most lethal and dangerous types of uxo found in all war-affected countries. a notable aspect of this uxo type is its "elusiveness," as such threats are typically discovered by chance, often during excavation for sewage or water pipes or the foundation work of buildings, when an unidentified explosive device is encountered. this category includes explosive devices with a charge of 500 kg or more, with wwii-era aerial bombs being the most common. the unique risk with this uxo type lies in the potential consequences of detonation or relocation, as it can endanger an area within a 500-meter radius, with severe repercussions. consequently, the disposal or removal of large-mass uxos, particularly aerial bombs, is handled with extreme caution. figure 8. example of large mass uxo dss vol. 5, no. 2, 2024, pp. 84-107 92 4. demining (process of landmines removal) demining is the process of removing landmines from an area, making it safe for human use. landmines are explosive devices that can cause severe injuries or death to people and animals who trigger them. often used in wars and conflicts, they remain a threat long after hostilities have ended. according to the „landmine monitor 2020“ report, 5,554 people were harmed by landmines and other explosive remnants of war in 2019, 43% of whom were children. different demining methods are used depending on the type, location, and quantity of landmines, as well as available resources and technology. conventional methods include the use of probes, metal detectors, dogs, and mechanical devices to locate and remove landmines. developing methods involve technologies like electromagnetic sensors, vapor detection, dispersed explosives detection, acoustic/seismic detection, unmanned ground vehicles, and drones. demining can serve military or humanitarian purposes. military demining focuses on quickly and effectively clearing a path through a minefield, using tools like mine plows and blast waves. humanitarian demining aims to remove all landmines to a specific depth, ensuring that the area is completely safe for civilian activities. specialized organizations perform humanitarian demining, following international standards and guidelines. this process is essential for reducing the risk of casualties, restoring access to land and infrastructure, enabling socio-economic development, and promoting peace and security. the history of demining dates back to world war i, when soldiers used rudimentary tools like bayonets, knives, and probes to locate and remove mines. since then, demining has evolved into a more sophisticated and systematic activity involving a range of technologies such as metal detectors, ground-penetrating radar, robots, drones, and trained animals like dogs and rats. however, demining remains a challenging and costly endeavor due to factors like the type, age, and condition of mines, terrain, weather, vegetation, resource availability, and security considerations. demining faces obstacles as both a humanitarian necessity and a technical challenge. millions of landmines remain scattered across more than 50 countries, causing death, injury, displacement, poverty, and environmental degradation. while demining is crucial for protecting lives and livelihoods, restoring peace and stability, enabling development and reconstruction, and upholding human rights and dignity, it faces challenges such as funding shortages, lack of coordination, insufficient data, limited standards, innovation needs, and political will.therefore, demining requires not only technical solutions but also political strategies to address the root causes of the landmine problem and prevent its recurrence. global demining organizations are dedicated to clearing landmines and other explosive remnants of war in conflict-affected areas. they also provide humanitarian aid, risk education, and advocacy for the rights of victims and survivors. according to landmine monitor 2021, more than 60 countries and territories remain contaminated with mines, posing a serious threat to the safety and livelihoods of millions. these organizations work with local communities, governments, and international partners to implement effective and sustainable mine action solutions. leading organizations in this field include halo trust, mines advisory group, norwegian people’s aid, danish demining group, and handicap international. 4.1. most effective methods for detection and removal of mines and unexploded ordnance (uxo) mine detection is the process of locating and identifying the presence of landmines or other explosive devices on land, in water, or elsewhere. this process uses various technologies and techniques to detect potentially dangerous devices and reduce the risk of injury or death. detection often involves metal detectors, vibration sensors, or other specialized equipment that can identify the presence of metal or materials characteristic of mines. this is a crucial step in the demining process or in ensuring safety in areas with landmine risks. as technology advances, new methods and approaches in mine detection are continually developed, incorporating diverse sensor methods. alongside technological advancements in detection methods, removal techniques have significantly improved in efficiency due to better and more precise detection. mine removal involves safely removing or disabling mines or other explosive devices placed on land, in water, or elsewhere. the goal of this process is to minimize the risk of explosions and protect people, vehicles, and property from harm caused by mines. the interdependence of detection and removal systems is crucial for the overall outcome and the success rate in clearing areas of mine-explosive remnants, especially in humanitarian demining, where un standards require a 99.6% demining success rate. in light of this, the following paper will discuss several detection and removal methods that have proven highly effective in the field. dss vol. 5, no. 2, 2024, pp. 84-107 93 4.2. methods for detecting mines and uxo mine detection is the process of locating and identifying the presence of mines or other explosive devices placed on land, in water, or elsewhere. this process employs various technologies and techniques to detect potentially hazardous devices, thereby reducing the risk of injury or death. mine detection typically involves the use of metal detectors, vibration sensors, or other specialized equipment capable of identifying the presence of metal or other materials characteristic of mines. this is a crucial step in the demining process or in securing areas at risk of mines. with advancements and refinements in technology, continuous work is being done on new methods and approaches for mine detection across different sensing methods. the primary classification of detection methods, as shown in the following table, includes [7,8,9]: 1. biological (biosensor-based), 2. electromagnetic, 3. optical, 4. acoustic, 5. nuclear, 6. mechanical. 4.2.1 biological (biosensor) method of mine detection the biological method of mine detection is a technique that utilizes living organisms to identify the presence of mines or explosive devices in a given area. these organisms possess highly developed senses, such as smell or sight, enabling them to detect specific odors or signals associated with mines. biological detection methods are often employed due to the high reliability of living organisms as detectors, their ability to quickly search large areas, and the relatively low cost compared to other detection techniques. however, these methods require training and maintenance of the organisms and ensuring their safety throughout the detection process. this method includes the use of dogs, rodents, bees, plants, and bacteria. figure 9. biological landmine detection with trained dogs 4.2.2 electromagnetic methods for mine and uxo detection electromagnetic detection methods use electromagnetic principles to identify objects or materials on or beneath the ground surface. these methods are widely applied in fields such as mine detection, geophysical research, archaeology, and geology. the principle of electromagnetic detection is based on changes in the electromagnetic field when materials with different electrical properties are present in the ground or underwater. these field changes can be registered and analyzed to identify targets of interest, such as minefields or archaeological remains. electromagnetic detection methods employ various techniques and instruments, including ground penetrating radar (gpr), electromagnetic mapping (em), metal detectors, and other specialized devices. each of these techniques has its strengths and limitations and can be adapted to the specific needs of a survey or application. their use is extensive and diverse, offering valuable information in multiple fields. these methods provide a quick and non-invasive way to detect mines, particularly below the ground surface, reducing the need for physical digging or probing. however, it is essential to consider the specifics of each dss vol. 5, no. 2, 2024, pp. 84-107 94 method, including penetration depth, sensitivity to surrounding interference, and the requirement for trained personnel to achieve optimal detection efficiency. ground penetrating radar (gpr) detection operates by transmitting an electromagnetic signal into the ground and detecting the reflected signal with a receiver. the transmitter emits a pulse wave or continuous wave at a specific frequency. the receiver collects waves scattered back from discontinuities in permittivity. these discontinuities can be caused by buried objects like landmines (the useful signal) and natural irregularities in the soil (background noise). a key advantage of this technique is its ability to detect plastic objects buried underground, making it suitable for finding various types of landmines with different casings. gpr can also provide information on the target's depth and is relatively insensitive to small metal fragments. however, gpr technology faces challenges. microwaves are heavily attenuated in certain types of conductive soils, such as clay, making wet clay an extremely challenging environment for detection. very dry soils, on the other hand, have reduced electrical contrast compared to plastic landmines, which can make these types of mines difficult to detect. thus, while gpr offers valuable capabilities in detecting plastic-encased mines, its effectiveness depends significantly on soil conditions, which can limit reliability in some environments [1,2]. figure 10. visual presentation of landmine detection using gpr with drone scanning 4.2.3 optical detection using lidar systems lidar (light detection and ranging) mine detection systems utilize laser beams to scan terrain in detail, enabling the identification of mines through a high-resolution, three-dimensional terrain map. lidar operates by emitting short laser pulses toward the ground and measuring the time it takes for them to reflect back. based on this reflection time, lidar generates a detailed 3d image of the landscape. variations in terrain elevation or the presence of objects, such as mines, cause differences in the reflection of the beam, enabling the identification of minefields. simply put, the system identifies changes in surface structure that suggest the presence of mines or unexploded ordnance (uxo). mines or uxos typically alter the terrain's topography or create distinctive shapes detectable through lidar technology. advantages of lidar in mine detection include high resolution, rapid terrain scanning, the ability to penetrate through vegetation, and the capability to detect mines even beneath surface soil layers. this technology allows for swift identification of potentially hazardous areas and precise minefield mapping, aiding safe demining and restoration of affected areas. moreover, combining lidar with other detection methods, such as metal detectors or ground-penetrating radar (gpr), can enhance detection accuracy and dss vol. 5, no. 2, 2024, pp. 84-107 95 reduce the risk of missed mines. due to its precision and reliability, lidar is increasingly valued as a tool in mine detection efforts, providing critical support in making affected areas safer [1]. figure 11. visual presentation of landmine detection using lidar with drone scanning 4.2.4 acoustic methods for detecting landmines and uxo acoustic methods for landmine detection are employed to identify the presence of mines in the field by analyzing sounds that they produce or reflect. these methods rely on distinctive acoustic signals emitted by a mine or the surrounding soil when exposed to certain external influences, such as impacts or vibrations. the operating principle of acoustic mine detection is based on detecting characteristic sounds generated when a mine responds to external stimuli, like mechanical vibrations or impacts. these sounds can be specific to certain types of mines or their components, enabling their identification using sensors or microphones. acoustic waves present a viable means for detecting and identifying landmines. common acoustic detection techniques include ultrasound and acoustic-seismic (a/s) methods. figure 12. visual presentation of landmine detection with acoustic method dss vol. 5, no. 2, 2024, pp. 84-107 96 4.2.5 nuclear detection of landmines nuclear detection of landmines is an innovative approach in demining, used to identify the presence of explosive materials, including those in landmines, by leveraging nuclear reactions and characteristic radiation. this technique has a long history of research and development, dating back to the late 1940s and 1950s, when the application of nuclear physics in mine detection was first explored. nuclear mine detection offers several advantages, including high sensitivity to the presence of explosives, rapid detection, and the ability to operate in diverse environmental conditions. however, challenges remain, such as the requirement for highly specialized equipment and trained personnel, as well as the safety and environmental concerns associated with the use of nuclear materials. despite these challenges, nuclear mine detection continues to hold promise as a valuable technique contributing to the advancement of safer and more efficient demining strategies in affected areas. common nuclear detection techniques include nuclear quadrupole resonance (nqr) and neutron-based methods. figure 13. visual presentation of landmine detection nuclear method, using nqr sensor 5. mines and uxo clearance methods mine clearance is a complex process requiring high precision and specific safety measures to protect personnel in the field. for this purpose, mine clearance is generally divided into four main categories: manual clearance, mechanical clearance, explosive clearance, and clearance using robotic systems. the most efficient and effective method is mechanical clearance, which can, in certain aspects, be combined with roboticassisted clearance. mechanical clearance of mines and unexploded ordnance (uxo) involves the use of appropriate and specialized equipment approved and regulated by the international mine action standards (imas), as well as specific national mine clearance regulations and legislation, depending on the country facing the mine contamination problem. mechanical mine clearance using demining machines is a critical technology in mine action operations. these demining machines are specialized vehicles or devices designed to search, identify, and clear mines from contaminated areas, either independently or in support of human intervention. they allow for faster, safer, and more effective clearance of mine-contaminated zones, reducing injury risks and accelerating the demining process. demining machines have a history that spans over a century, with early adaptations observed in tanks from world war i and ii, repurposed to clear pathways for combat. in a military context, the objective was to neutralize enough hazards to ensure the relative safety of advancing troops, even if some risks remained acceptable. today, various demining machines are utilized in humanitarian mine action (hma). some are designated as “clearance machines,” suggesting the capability to remove all explosive hazards to a certain depth. dss vol. 5, no. 2, 2024, pp. 84-107 97 however, no machine that interacts with the ground can reliably achieve this. machines that excavate and sift through soil before manual inspection can render areas safe, but this method tends to be slower, more costly, and environmentally damaging compared to manual clearance, particularly over large areas. in high-risk zones, such as trenches or destroyed buildings, machines like excavators and screens can effectively manage hazards while minimizing environmental damage. figure 14. early examples of mechanical demining, 1st world war, mark iv tank that has been adapted for mine clearance figure 15. mechanical demining during world war 2, t10 mine explorer, rebuilt tank m4a2 nevertheless, demining machines have limitations: they often do not trigger all types of pressure-activated devices and may leave hazards in a more sensitive state. additionally, they can inadvertently spread hazards over a wider area, complicating subsequent manual clearance efforts. the use of demining machines to expedite operations at the expense of safety contradicts the goals of hma (humanitarian mine action). the capabilities of these machines must be thoroughly assessed based on anticipated hazards, inherent risks, and the actual costs of implementation. claims regarding the efficiency of machines are often exaggerated, and manufacturer recommendations may not align with practical applications. real-world trials, rather than merely ideal conditions, should inform the planning and utilization of machines to understand their limitations [1]. an objective assessment of machine limitations could have prevented issues such as the use of rotary mine rakes on compacted dirt roads. in such cases, tree roots beneath the surface of the road could become entangled in the rake's teeth, disrupting rotation and causing damage. moreover, the presence of rocks or bedrock could result in mechanical damage to the machine or necessitate a reduction in processing depth. in sandy areas devoid of rocks and roots, the soil was reduced to a deep layer of fine dust, making it impassable for vehicles. consequently, all unexploded ordnance (uxo) and smaller explosive hazards remained buried in the dust, while larger threats could be displaced beneath the surface. as vehicles were compelled to veer off the road onto adjacent land, accidents ensued, particularly if a minefield lay hidden below. the machine's effectiveness in eliminating all explosive hazards was compromised, posing increased risks to civilians and escalating search and clearance operation costs. marketed as a "threat reduction machine on roads," its implementation, along with detailed search and clearance procedures, could potentially clear pathways. however, due to the deep layer of dust, anti-tank mines with minimal metal content went undetected. nonetheless, cost-effective demining machines can indeed offer economical solutions and significantly accelerate the release of land when reasonably integrated with original search and clearance protocols. dss vol. 5, no. 2, 2024, pp. 84-107 98 over the previous years, technological advancements have led to the development of increasingly sophisticated demining machines, which have become vital tools in the demining process worldwide. the removal of mines using demining machines represents a crucial tool in the fight against thretas such as landmines, providing a safe, efficient, and precise solution for clearing affected areas of mine hazards, saving human lives in the process. 6. advancements in technology and demining machines technological advancements have enabled the development of various types of demining machines, including: 1. armorded vehicles with mine detonation systems: these vehicles utilize heavy and robust systems for detonating mines, allowing for the safe destruction of mines while keeping the vehicle protected from explosions. 2. robotic demining systems: these autonomous robots are equipped with sensors and manipulative systems that enable precise terrain scanning and mine removal without the need for human operators in the risk zone. 3. minefield clearing machines: these machines are designed for rapid clearing of large areas contaminated by mines, employing a combination of techniques such as sweeping, demolition, or removal of mines. the advantages of technology and demining machines are: 1. safety: the use of demining machines reduces the risk of injury or death for deminers, as operators do not need to physically approach the mines. 2. efficiency: machines facilitate faster and more effective mine removal, contributing to the quicker release of affected areas. 3. precision: some systems, such as robotic demining machines, offer high precision in detecting and deactivating mines. disadvantages of technology and demining machines are: 1. costs: the acquisition, maintenance, and operation of demining machines can be expensive. 2. terrain limitations: certain terrains may be difficult for machines to access, which can limit their effectiveness. 3. technical challenges: technical issues or failures may occur during the operation of demining machines, necessitating additional time and resources for repairs or replacements. 7. demining machines in humanitarian mine action (hma) machines are utilized in humanitarian mine action (hma) for two primary purposes: 1. to improve the safety of demining personnel. 2. to accelerate the land clearance process. since there are no established minimum competencies for individuals operating demining machines according to the international mine action standards (imas), it is the responsibility of each organization to ensure comprehensive training and deployment protocols. this section addresses the use of a specific range of machines but should be expanded whenever a machine not covered is intended for use in potentially hazardous areas. to ensure the proper utilization of each machine, all personnel involved in task assessments must be well-informed about the optimal operating conditions of the machine, its limitations, and constraints in application. this knowledge will enable task planners to select the most appropriate machine or combination of machines and tools to achieve the most efficient results. mechanical demining involves the use of machines in potentially hazardous areas during demining operations. this may include a single machine with one tool, one machine with multiple tools, or multiple machines with different tools. machines with proven effectiveness are employed to prepare the area and provide armored dss vol. 5, no. 2, 2024, pp. 84-107 99 protection for personnel. area preparation machines are designed to enhance the efficiency of demining operations by removing vegetation, exposing hazards, or preparing the ground surface. in some instances, they may relocate the surface soil for searching and clearance in another area. although these machines can detonate some hazards, they are not intended to eliminate all explosive threats. machines designed to disturb the soil to a certain depth and neutralize all explosive hazards using tools such as rotating cutters or flails often fail to fulfill their intended purpose. however, they can still be useful for preparing breakthroughs or large areas when necessary. mine-protected vehicles (mpvs) are specifically designed to protect occupants from mine detonations. when equipped with appropriate wheels, they may attempt to detect certain hazardous areas by detonating pressureactivated or movement-sensitive hazards beneath the steel wheels, although this method is unreliable and generally not approved. mpvs can also be outfitted with extensive arrays of metal detectors mounted on the front or rear. detected signals must be confirmed and investigated manually. given the current technology, the effectiveness of mpvs is limited, and they should only be used if available at minimal or no cost. demining machines can be used for:  removing vegetation prior to manual clearance or search with mine detection dogs (mdd);  preparing the ground for manual searching and clearance;  assisting in locating hazardous areas by detonating one or more pressure-activated or movementsensitive threats in the area;  excavating soil and relocating it for search purposes;  building trust among land users where there is no threat evidence (nte), thereby eliminating the need for actual search and clearance operations. in general, when a threat has been detonated, the demining machine should not be used to deliberately detonate other threats in that area. this is because the machine may disrupt any existing pattern and scatter or bury threats in a manner that increases risk for deminers and prolongs the time required for manual search and clearance. the demining machine can be used to approach suspicious hazardous areas in other locations to attempt to confirm the direction and extent of any present pattern of pressure/movement-sensitive threats. 7.1 categorization of demining machines imas 09.50 classifies demining machines into three categories: mine clearance machines, land preparation machines, and mine-protected vehicles. the category is determined by the primary use of the machine: 1. mine removal machines: these machines are designed to destroy mines. they are equipped with tools suitable for this task, such as flails, cutters, screens, rollers, or a combination of these tools. 2. land preparation machines: these machines are intended for removing vegetation or other obstacles to prepare the area for subsequent clearance activities. 3. mine-protected vehicles: these vehicles are used as platforms for detection systems in suspected hazardous areas (sha). for a comprehensive list of mechanical demining equipment and examples of various machines, refer to the gichd mechanical demining equipment catalogue 2008. annex a in this catalogue provides a summary of tasks typically associated with each category. there is some overlap between the tasks of these three categories. demining machines are primarily used in four roles: 1. destroying mines. 2. preparing land (and possibly destroying mines, though not always). 3. confirming the presence of mines. 4. serving as a platform for other tools or applications. some demining machines may simultaneously serve multiple purposes. for example, a machine with a ground-engaging tool such as a flail can destroy mines, remove vegetation, and loosen soil during demining operations. if equipped with a magnet, the machine could also remove metallic debris and gather information about mines and explosive remnants of war (erw) [1]. dss vol. 5, no. 2, 2024, pp. 84-107 100 machines can be further categorized into: 1. weight classification (light, medium, or heavy). 2. invasive (designed to operate within suspected hazardous areas sha). 3. non-invasive (designed to operate from safe ground while "penetrating" into suspected hazardous areas sha). 4. remote-controlled (designed for remote operation from a safe distance). 5. on-board control (designed to be operated by a driver/operator from a protected cabin). 7.2 mine clearance machines mine clearance machines are designed for the detonation, destruction, or removal of landmines. for example, a front loader that is armored and modified for excavating mined soil qualifies as a mine removal machine, as the definition includes the removal of mines. the primary types of mine removal machines include:  flails,  tillers,  machines with a combination of tools,  custom civil or military facilities for clearing or removing mines. figure 16. dok-ing mv-10 bison-flail system of demining figure 17. pt 300-d-tiller system of demining dss vol. 5, no. 2, 2024, pp. 84-107 101 7.2.1 flails flail systems are the most common type of equipment for mechanical demining in the current market. they have a long history, with prototypes used in world war i and extensively during world war ii. however, significant development of flail systems slowed until the early 1990s, when humanitarian demining spurred advancements in flail technology. more resources have been invested in research and development to improve flails than in any other demining system. flails have evolved primarily due to market forces, with private engineering firms driving improvements for profit. national armies have also contributed to their development. figure 18. flail wheel the fundamental working principle of flails involves a rotating shaft, axle, or drum with lengths of chain links attached to their surface. these chains deliver powerful impacts to the ground when rotated at high speeds. some flail designs are particularly effective against anti-tank mines. the distance of the chains from the flail unit's axle allows for a standoff that enables the explosion to somewhat dissipate before impacting the vehicle's chassis. however, flails are primarily considered effective tools against anti-personnel mines and small unexploded ordnance (uxo) [11]. characteristics of flail wheel the length of the chain striking the ground at a specific speed constitutes the basic operational methodology of all flail systems. the objective is to target the ground and/or the mines and unexploded ordnance (uxo) within it. the impact of the flail on the target is referred to as the flail strike. three characteristics of the flail strike have been identified (fig. 19): the disruptive strike, the detonation strike, and the ejection strike. the disruptive strike occurs when the flail's impact physically damages a mine or uxo. in the worst-case scenario, the weapon remains functional but becomes more dangerous. ideally, a disruptive strike will render the munition non-functional by shattering it. fully functional mines can be disrupted by the flail, causing the detonation mechanism to fail. additionally, some mines may already be non-functional before being struck. there is no known method to predict the ratio of functional to non-functional mines that will be disrupted. the detonation strike occurs when the flail's impact triggers the detonation of a mine or the ground above it by activating a series of detonators. this helps to reduce the area of contamination by immediately indicating the presence of mines. however, detonations are not always complete; sometimes the detonator activates, but the main charge of the mine does not explode, often due to moisture. these are referred to as partial detonations. factors such as the type of mine, ground conditions, engine power, penetration capability, and the machine's forward speed affect whether a mine will detonate or be disrupted during flailing. the ejection strike occurs when the flail's impact causes a mine to be lifted and ejected from the flail unit. although ejections are relatively rare, they are likely caused by an incomplete impact of the chain link that lifts the mine, momentarily entangling it in the rotating chains before ejecting it forward or sideways. if a mine falls onto the path of the machine, it is likely to be detonated or broken upon a subsequent strike. however, mines thrown into previously cleared or non-suspicious areas create new suspicious zones. this issue raises significant concerns for critics of flail systems as primary tools for clearance. nonetheless, improvements made by mechanical engineers have significantly reduced the occurrence of ejections in certain flail systems, according to field operators [1]. dss vol. 5, no. 2, 2024, pp. 84-107 102 figure 19.types of flail system strikes effectiveness of the flail method the overall efficiency parameter of flails is the centrifugal force exerted by the impact hammer and chain. this force is subordinate to the selection of chain length, but most importantly, it is influenced by the choice of the hammer head or type of impact hammer. earlier in the text, we briefly outlined some of the types of impact hammers used in this method. the most effective type of impact hammer is the t-shaped design with a sharpened bottom edge (as shown in fig 20). figure 15 illustrates the forces exerted by the flail on the ground. from this depiction, we can see that this type of hammer, in a certain way, excavates the soil in front of the mine, leading to situations where the mine becomes uncovered and left exposed, which increases the risk, as the condition of the mine remains unknown. this is indeed one of the drawbacks of this demining system, particularly in soils with higher moisture content. the method can be improved by introducing additional hammers on longer or shorter chains or by combining it with other types of hammers, such as balls. despite the existence of certain drawbacks, the flail method is highly effective in destroying mines, as evidenced by the images below [1]. figure 20. type of flail chain head shape, most effective shape for landmine clearance, with technical data dss vol. 5, no. 2, 2024, pp. 84-107 103 figure 21. flail forces acting on the ground 7.2.2 tillers the tiller system represents the second-largest family of specialized demining machines. most mills are based on the chassis of a tank or forestry machine, which makes them heavy and large, although lighter designs are also emerging. a mill typically features a rotating drum with overlapping rows of alloy steel teeth or blades that grind and chew the soil to a selected depth. this process detonates or shatters anti-personnel mines, smaller unexploded ordnance (uxo), and sometimes even anti-tank mines. due to their size, mills can be challenging to operate in areas with poor infrastructure. however, when used correctly in suitable environments, these powerful machines effectively "brutalize" suspicious terrain, ensuring that few explosive devices escape destruction. most milling systems are produced in austria, germany, and sweden, with five manufacturers producing mills ranging from 14 to 53 tons. there are also combined systems, such as the sts minewolf mill/flail (24.7 tons with a milling system) and the redbus mineworm, which is part of the land mine detection system (lmds) and weighs 15 tons. figure 22. tiller dss vol. 5, no. 2, 2024, pp. 84-107 104 characteristics of tiller the tiller operates using sharp knives, teeth, or bits attached to a rotating drum powered by a heavy-duty motor (high-torque electric motor). the milling unit directly penetrates the soil, extracting material to a depth ranging from 0 to 40 centimeters at the operator’s discretion. this interaction with the ground and all the explosive devices within it is referred to as the “bite.” three characteristics of the mill’s bite have been identified concerning their effects on mines/uxo, similar to those observed in the impact of flails. these are briefly discussed below (fig. 23). disruptive bite the disruptive bite occurs when the milling unit physically damages mines/uxo through contact with its bits. explosive devices can be shattered to the point of becoming harmless or only partially functional, potentially becoming more unstable than before. mines/uxo are likely to be disturbed if their fuses are non-functional (i.e. if they are defective) or if the angle of attack of the mill prevents direct contact with the fuse, causing the casing to rupture before the explosive devices can function properly. disruptive bites result in a positive outcome when the explosive devices are sufficiently broken to no longer pose a threat. detonating bite the detonating bite refers to the destruction of explosive devices through detonation. when the mill strikes a mine/uxo or exerts pressure, particularly on hard ground, it can activate the fuse mechanism. instances in which the fuse operates but the main charge does not detonate are considered partial detonations and fall under the category of detonating bites. ejecting bite the ejecting bite occurs when a mine is lifted from its position in the ground and thrown to a new location. similar to flails, this results in ejection. ejecting bites from mills are rare, and when they do occur, the explosive devices are typically thrown in a line in front of the machine rather than to the side. reports from the field suggest that ejecting bites from mills is less problematic compared to those from flails [1]. figure 23. types of tiller system bite effectiveness of the tiller method the design of the tiller is based on the principle of soil excavation and mine neutralization. the soil excavation mode demonstrates the relative rotation of the rotor in relation to the movement of the machine, indicating the direction in which the soil beneath the rotor is expelled. the counterclockwise mode of soil excavation is used to neutralize mines beneath the rotor, while the same direction is employed to neutralize mines in front of the rotor. dss vol. 5, no. 2, 2024, pp. 84-107 105 one of the disadvantages of this demining system is the potential damage to the tips of the mill (breakage of the spikes). this is due to the soil composition encountered by the machine, particularly when it comes across certain stones. in both cases, with the flail method and the milling method, the drawbacks are influenced by the soil composition on which the machines operate, making it difficult to implement preventive measures [1]. figure 24. the most effective tiller shape for mine clearance figure 25. tiller forces acting on the ground dss vol. 5, no. 2, 2024, pp. 84-107 106 7.2.3 the most effective method for landmine removal using the mechanical principle (independent positioning of flail and tiller) the independent positioning of the flails and the milling cutter allows for different operational speeds and various excavation depths. for mine destruction, the primary role is assigned to the flail, as illustrated in the image below. figure 26. demining machine with flail and tiller system the independent positioning and movement of the flails and milling cutter in relation to the excavation depth provides greater efficiency compared to the conventional arrangement with two flails. the combination of flails and milling cutters offers specific advantages when excavating different types of soil. depending on the demining requirements, the excavation depth and the number of revolutions can be adjusted to achieve higher operational speed and better work efficiency. each segment of the milling cutter can have multiple heads positioned at a relative angle of 120°. the segments are phased so that the cutting heads form three spirals that start from the center of the rotor and symmetrically extend outward on each side [1]. the destruction of high-power mines must be carried out with the primary tool a flail with a large radius that will not be damaged. the milling cutter, as a secondary tool, is adequate for adjusting the excavation depth and completely clearing mines. in summary, the combination of the flail as the primary tool and the milling cutter as the secondary tool offers the following advantages:  more flexible handling of different working conditions with two independent working tools.  the ability to independently adjust the excavation depth and the number of revolutions of both the flail and the milling cutter.  adaptation to actual demining conditions.  the two tools, the flail and milling cutter provide double efficiency.  high reliability in destroying different types of mines.  the flail destroys the most destructive anti-tank mines, avoiding significant damage to the machine.  the milling cutter is lighter than the second flail, conserving material and engine power.  the milling cutter destroys the smallest components.  the milling cutter can be adjusted to determine the final excavation depth. 8. conclusions the persistent threat of landmines poses a significant global challenge, particularly in regions like bosnia and herzegovina, where decades of conflict have left vast areas contaminated and unsafe. the presence of these explosive remnants of war not only endangers civilian lives but also hampers socioeconomic development and the safe use of land for agriculture and habitation. to address the complex problem of landmines, advanced detection technologies such as ground penetrating radar (gpr) and lidar systems offer promising solutions. these innovative detection methods enhance the ability to identify buried mines with high accuracy, reducing the risk to demining personnel and increasing the efficiency of clearance operations. dss vol. 5, no. 2, 2024, pp. 84-107 107 in conjunction with effective detection strategies, innovative concepts for mine destruction are essential. the combination of flail and tiller systems presents a powerful approach to the safe and thorough destruction of landmines. by integrating the destructive capabilities of flails, which excel at neutralizing various types of mines, with the precision of tillers, which can effectively prepare the terrain, this combined system maximizes operational efficiency and safety. such advancements in technology and methodology not only promise to expedite the demining process but also aim to ensure the safety of operators and communities affected by landmines. as we move forward, a multifaceted approach that incorporates cutting-edge detection tools and innovative destruction techniques will be crucial in mitigating the landmine threat and restoring safety and usability to affected regions like bosnia and herzegovina. funding information no funding was received from any financial organization to conduct this research. declaration of competing interest the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. references [1] d. mikulić, design of demining machines, springer, 2013. [2] „antipersonnel mines“; https://military-history.fandom.com/wiki/anti-personnel_mine#blast_mines, (accessed jan.19, 2024). [3] „antipersonnel blast mines“; https://military-history.fandom.com/wiki/land_mine, (accessed jan.19, 2024). [4] „antipersonnel directional mines“; https://en.wikipedia.org/wiki/anti-personnel_mine, (accessed jan.19, 2024). [5] n. zukan, danger of remnant mines in bosnia and herzegovina, mechanical engineering faculty sarajevo, master thesis, 2020. [6] „what is unexploded ordnance (uxo)“, https://www.1stlinedefence.co.uk/unexploded-ordnance-uxo/, (accessed jan. 20, 2024) [7] s. masunaga, k. nonami, controlled metal detector mounted on landmine detection robot, international journal of advanced robotic systems, vol 4, no. 2, pp. 237-245, 2007. [8] l. junghan, l. haengseon, k. sunghyub, j. daehyeong, h. jongwu, modeling and implementation of a joint airborne ground penetrating radar and magnetometer system for landmine detection, remote sensing, vol. 15, no. 15, 2023. [9] h. kasban, o. zahran, sayed m. elaraby, m. el-kordy, f. e. abd el-samie, a comparative study of landmine detection techniques chapter 4. mine detection techniques, springer science+business media, llc 2010. [10] hma global sops chapter 8: mechanical demining, december, 2018. [11] a handbook of mechanical demining, geneva international centre for humanitarian demining (gichd), july 2009. [12] a study of mechanical application in demining, gichd, geneva, may 2004. microsoft word detection of exoplanet_catovic (2).docx (online) issn 2744-1741 defense and security studies original research vol. 6, no. 2, 2025, pp.142-157 https://doi.org/10.37868/dss.v6.id300 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 142 detection of extrasolar planet wasp-10b by differential photometry using amateur optics alan catovic*1, dzan jasarevic 1 mechanical engineering faculty, university of sarajevo, bosnia and herzegovina *corresponding author e-mail: catovic@mef.unsa.ba received: oct. 4, 2025 revised: nov. 22, 2025 accepted: nov. 24, 2025 online: nov. 27, 2025 abstract this study presents the detection and characterization of the exoplanet wasp-10b using differential photometry performed with amateur astronomical equipment. an overview of exoplanet properties, detection techniques, and the transit method is provided, followed by a description of the observational setup, recording procedures, calibration, and data processing workflow. more than one hundred ccd images were acquired using an 8-inch schmidt–cassegrain telescope and a monochrome atik 383l+ camera, with additional calibration frames to correct instrumental noise and vignetting. differential photometry was carried out using astroimagej, enabling precise extraction of the stellar flux of wasp-10 relative to nearby reference stars. the transit light curve was modeled using the mandel & agol analytic formalism, from which key planetary parameters were estimated. results yield a planetary radius of approximately 1.12 rj and an orbital inclination of 89°, both in good agreement with published values. the study demonstrates that high-precision exoplanet transit measurements are achievable with advanced amateur-level equipment, offering valuable scientific and educational contributions to exoplanetary research. © the author 2025. published by arda. keywords: critical infrastructure; vulnerability analysis; defense of the country; event tree technique; monte carlo method, railway system 1. introduction extrasolar planets (exoplanets) are planets that orbit outside the solar system around a parent star. the number of extrasolar planets discovered increases every year due to the invention of new detection methods or the improvement of existing ones. the first extrasolar planets orbiting their parent stars were discovered only in the 1990s. the discovery of these planets also raised the very exciting question of the possible existence of life on them. from 1998 to december 2025, 6045 extrasolar planets were discovered. the first planet that was discovered (in 1995) outside the solar system is 51 pegasi b. the kepler space telescope, using the transit method, discovered kepler-47, the first double star to have planets: kepler-47b and kepler-47c. in 2016, the planet hd 131399ab, a few million years old, was noticed in the constellation centaur, which is located in a triple star system (hd 131399a, hd 131399b, and hd 131399c), and astronomers believe that multiple stars are too unstable for the long-term survival of planets. dss vol. 6, no. 2, 2025, pp.142-157 143 harps (since 2004) has discovered about a hundred extrasolar planets, while the kepler space telescope (since 2009) has discovered more than 2,000 extrasolar planets. about 20% of sun-sized stars have earth-sized planets in the habitable zone. assuming there are 200 billion stars in the milky way, it is thought that there are at least 11 billion earth-sized planets where life is possible. if planets orbiting red dwarfs are included in that number, that number rises to 40 billion. kepler-37b is one of the smallest exoplanets discovered, orbiting the star kepler-37 in the constellation lyra. it has a radius slightly larger than the radius of the moon. another low-mass planet discovered is draugr (psr b1257+12 a, psr b1257+12 b, believed to orbit a pulsar), which is about twice the mass of the moon. the most massive planet found on the nasa exoplanet archive is denis-p j082303.1-491201 b, and has a mass of about 29 jupiters, although by some standards this planet can be classified as a brown dwarf. kepler-70b (it orbits the star kepler-70 in 5.76 hours) is one of the hottest exoplanets discovered, with a surface temperature of about 7140k. its density is 5500 kg/m3. some planets are so close to their host stars that they take only a few hours to orbit them, while others take thousands of years to complete one rotation. most of the planets that have been discovered are in the milky way, but there have been some potential detections of “extragalactic” planets. the closest extrasolar planet is proxima centauri b, 4.2 light-years (1.3 parsecs) from earth, and orbits proxima centauri, the star closest to the sun. there are indications that some form of life may be possible on proxima centauri b. one of the most distant exoplanets discovered is sweeps-11, which orbits the star sweeps j175902.67−291153.5 (in the constellation sagittarius), and is approximately 27,710 light-years away. in addition to extrasolar planets, there are also so-called "rogue planets" (e.g. wise 0855−0714), planets that do not orbit any star. the potential number of such planets is measured in billions. the oldest known exoplanet is psr b1620-26 b (also known as methuselah), about 12,400 light-years away in the direction of the constellation scorpius. the planet orbits two stars, a pulsar (psr b1620-26) and a white dwarf (wd b162026) and is the first planet discovered orbiting two stars. it is believed to be 12.7 billion years old. the youngest exoplanet discovered is v830 tau b, which orbits the t tauri star v830 tau, about 430 light-years away in the direction of the constellation taurus. the planet is believed to be about 2 million years old. one of the most studied extrasolar planets is a planet called hd 189733 b, which is about 63 light-years from earth, in the direction of the constellation vulpecula (the fox). the planet orbits the star hd 189733 a, with an apparent magnitude of 7.6, and spectral type k1-2v. with a mass about 15% greater than that of jupiter, the planet hd 189733 b rotates around its star in about 2.2 days, at an orbital speed of about 150 km/s. carbon dioxide has been detected in its atmosphere. in 2013, the color of the planet was discovered for the first time. by measuring the albedo, it was determined that the planet hd 189733b has a dark blue color. on the other hand, the planet gj 504 b appears to be predominantly purple in color. kappa andromedae b, on the other hand, has a reddish color. one of the darkest known exoplanets is tres-2b, a "hot jupiter" planet that reflects less than 1% of the light from its parent star, meaning it is less reflective than charcoal or black acrylic paint. these "hot jupiters" are expected to be so dark due to the sodium and potassium content of their atmospheres, but it is not known why tres-2b is this way perhaps due to some unknown chemical element. the large surface temperature variations on the exoplanet 55 cancri e have been attributed to possible volcanic activity, which releases large amounts of dust clouds that can blanket the planet and block thermal emissions. some exoplanets (1swasp j140747.93-394542.6, fomalhaut b) are thought to have rings around them, similar to those of saturn. the atmospheres of several exoplanets have been detected so far. the first planet with an atmosphere (discovered in 2001) was hd 209458 b. kic 12557548 b is a small, rocky exoplanet, very close to its parent star that is evidently evaporating and leaving behind a trail of clouds, something similar to a comet. volcanic dust can be found in these dust clouds that can leave the planet due to low gravity, and in the cloud, there can also be vaporization of metals due to high temperatures (due to the proximity of the star). scientists are monitoring possible biological indicators on exoplanets. for example, molecular oxygen (02) in earth's atmosphere is a result of photosynthesis by living plants and many types of microorganisms, so it can be used as an indicator of life on exoplanets [1], [2], [3], [4]. toi-4600 c is one of the most intriguing long-period exoplanets discovered in recent years. identified by nasa’s tess mission and confirmed through ground-based follow-up observations, toi-4600 c orbits its star dss vol. 6, no. 2, 2025, pp.142-157 144 roughly every 483 days, making it one of the longest-period planets ever detected by tess. the planet is believed to be a cold gas giant, comparable in size to saturn or jupiter, likely located near or beyond the system’s equivalent of the water-ice line. its long orbital period and relatively moderate stellar flux make it especially valuable for studying atmospheric evolution and migration histories of outer gas giants. toi-4600 c orbits a ktype star and forms part of a multi-planet system together with toi-4600 b, enabling comparative studies of planetary system architecture and dynamical stability [33]. 2. detection of exoplanets by differential photometry extrasolar planets around stars similar to the sun began to be found in large numbers only in the late nineties as a result of advanced telescope technology, but also ccd cameras and the possibility of computer image processing. such advances enabled more accurate measurement of the luminous flux of stars, allowing astronomers to detect planets, not visually (the luminosity of the planets is too low for such detection), but by measuring variations in the luminous flux of the star as the planet passes in front of it (the so-called transit method or differential photometry method). the transit method is used by nasa's kepler orbiting telescope. this method is also called the photometric or occultation method. about 97% of all confirmed exoplanets have been discovered using indirect techniques, most commonly radial velocity measurements and differential photometry (tracking the transit of an exoplanet in front of a star). in addition to these two techniques, there are also direct imaging techniques, gravitational microlensing, polarimetry, astrometry, etc. photometry deals with measuring the flux or intensity of electromagnetic radiation from astronomical objects. the main task of differential photometry of exoplanets is to create a light curve that clearly shows the drop in the luminosity of a star due to the transit of a planet in front of it (fig. 1). each point on this curve (fig. 1) represents the change in the magnitude of the parent star over a period of time. this means that when a planet passes in front of the star, a “dip” will appear in the light curve. this curve needs to be fitted so that the resulting function matches the experimental measurements as closely as possible. three important parameters for this curve (fig. 1) are: the "depth" of the transit, the time of the start of the transit, and the time of the end of the transit. the transit curve, with the knowledge of the radius of the parent star (r*), allows us to estimate the following parameters [7]:  the ratio of the radius of the exoplanet (rp) to the radius of the parent star (r*).  the ratio of the radius of the exoplanet's orbit (rorb) to the radius of the parent star (r*).  the central point of the transit tc and the duration of the transit t.  the inclination of the exoplanet's orbit. fig. 1 light curve of the exoplanet qatar-1b [5] dss vol. 6, no. 2, 2025, pp.142-157 145 how is this done in practice? reference [6] provides a step-by-step tutorial on this procedure. in short, a large number of images are taken during the night, taking into account a nearby comparison star (whose magnitude we know). exposures can be from 10s to 2 minutes for each image, and at least 4-5 hours of recording should be done. it is advisable to record 1 hour before and 1 hour after the start and end of the transit. sometimes up to a thousand images are needed to record the entire transit. a photometric program (e.g., maxim dl, vphot tool) is then used to determine the magnitude change of the host star using the technique of differential photometry. this means that the magnitude change of the exoplanet's host star is compared to the magnitude of a (non-variable) comparison star nearby. the advantage of differential photometry is that only the difference in luminosity between the parent star and one or more comparison stars is important. in this way, the influence of factors such as light pollution, background sky glow, and passing clouds is eliminated. high precision of measurement requires the use of special astronomical ccd cameras on which the recording time can be set very precisely and whose sensors are much better for this purpose than, for example, cmos sensors in dslr cameras. the detection of extrasolar planets using the transit method requires a fairly high measurement precision because the changes in the luminous flux of a star due to the transit of a planet are extremely small, and it is desirable that the orbital inclinations of extrasolar planets are close to an angle of 90°. the majority of extrasolar planets orbiting their host stars have an inclination of their orbits that is unfavorable for observation from earth (<90°). the magnitude of the change in the luminous flux of a star due to the transit of planets can best be described with a practical example. if, for example, if a planet the size of jupiter were to pass in front of a star the size of the sun, the change in light flux would amount to only 1.1%, while in the case of an extrasolar planet the size of earth, that change in light flux would be approximately 0.84×10-4%. for a planet the size of mars, the change in light flux intensity would amount to only about 0.3×10-5 %. the atmosphere greatly affects the quality of astrophotographic images of stars. the most important of these are phase fluctuation and scintillation. phase fluctuation is responsible for image shift (so-called cooking) and reduced visibility (so-called seeing), and is caused by the passage of light through different layers of the atmosphere, where the angle of arrival of the light rays changes, degrading the image. scintillation is a secondorder effect (causing the curvature of the wavefront) and results in a variation in light intensity over space and time. it is manifested by the twinkling of stars. adaptive optics on telescopes can somewhat reduce the effects of these disturbances. the advantage of the photometric method is that it can be used to identify a planet based on the light flux curve alone. this method, which is very important, can determine the approximate size of the planet being identified because the change in the intensity of the star's light flux during the transit of the planet is proportional to the ratio of the planet's radius to the star's. the star's radius is known in advance based on spectroscopy and is defined based on the star's luminosity and temperature values. in order to estimate the radius of an extrasolar planet very precisely, however, a telescope with a large objective diameter is required. currently, this is done with telescopes of the 1m class and above, such as the trappist and lgoct telescope systems. also, with larger telescopes, the atmosphere of the transiting planet can be investigated. namely, when a planet moves in front of the star, the light from the star itself passes through the upper layers of the planet's atmosphere. by analyzing the spectrum of a given star (using spectroscopic equipment with higher resolution), chemical elements present in the atmosphere of a given planet can also be detected. the study of the atmosphere is of great scientific importance because it can provide a picture of the conditions prevailing on a planet – what gases it consists of, what the surface temperature is, whether there is liquid water on it, and even whether there is any form of life. for example, the presence of o2 or o3 molecules in the atmosphere of an exoplanet (detectable only by telescopes with an objective diameter of more than 2.5 m) can signal the existence of some form of life. in addition, perturbations in the transit times of extrasolar planets can be used to estimate the presence of other planets around the same central star [6]. 3. research methods for detecting exoplanets the experimental research method involves systematic astrophotographic imaging of a selected candidate star, with the objective of detecting extrasolar planets through the transit method. this technique relies on measuring the slight reduction in the star’s observed luminous flux when a planet passes in front of its disk, partially blocking the stellar light. in practice, this requires capturing a long sequence of calibrated images over several hours, ideally starting before the predicted transit and continuing after it has finished. dss vol. 6, no. 2, 2025, pp.142-157 146 throughout the analysis, a uniform surface brightness (luminous flux) across the stellar disk is assumed, allowing the observed decrease in flux to be attributed solely to the opaque silhouette of the transiting planet rather than intrinsic stellar variability or non-uniform emission. this assumption simplifies the mathematical interpretation of the light curve and enables the extraction of key planetary parameters such as radius ratio, orbital inclination, and transit duration. recording consists of the following procedures [7], [8], [9]:  setting up and verifying the assembly.  setting up the main telescope and auxiliary telescope.  setting up the camera to guide the telescope.  mounting the ccd camera on the main telescope.  placing a special filter in front of the ccd camera to eliminate the blue part of the star's spectrum, which is the most scattered in the earth's atmosphere and contributes the most to measurement errors.  taking at least several hundred astrophotographic images of each candidate star, which will be used to analyze the brightness of the star for a certain time period (planet transit period).  it is necessary to perform precise time synchronization on the camera (eg, dimension 4 program).  you need to know which time system is used: julian date/universal coordinated time (jd_utc), heliocentric julian date/universal coordinated time (hjd_utc), or barycentric julian date/barycentric dynamical time (bjd_tdb).  software is used: eg maxim dl for recording, and eg phd2 program for telescope guidance. the software recording procedure consists of the following [7], [8], [9]:  connecting the ccd camera with the maxim dl program.  recording of monochrome images in fits format.  depending on the resolution and the so-called seeing (atmosphere), brighter stars should be defocused min. 3 pixels in diameter, preferably 5-10 pixels.  shot exposures: generally 10-120 s.  shooting sensitivity iso 100-200. the differential photometry method involves the analysis of a large number of images, analyzing the intensity of the light flux from the observed star for the entire duration of the transit of an extrasolar planet. the shape of the light flux curve generally depends on the ratio of the radius of the planet to the central star, the latitude of the transit over the parent star, and the darkening of the edges of the stellar disk (so-called limb darkening). in this work, the software maxim dl was used, which enables very precise differential photometric measurements of the star for each measurement performed. maxim dl also enables the export of the received data on the intensity of the light flux so that they can be processed in some of the software suitable for data analysis (e.g., matlab). reference stars used in photometry should have a magnitude as close as possible to that of the potential exoplanet host star, but it is also advisable to be of the same type of star. a good tool for selecting these stars is the aavso's variable star plotter (vsp) utility [10]. data processing and regression analysis methods used involve also the graphical representation of the change in the luminous flux for a candidate star in a certain time interval, based on a large number of calibrated astrophotographic images. regression analysis of the obtained data defines the function of the change in the luminous flux intensity of a given star during the transit of an extrasolar planet. the curves are processed in software (e.g., matlab, excel), which has a special tool (e.g., curve fitting toolbox in matlab) for regression analysis. dss vol. 6, no. 2, 2025, pp.142-157 147 within the framework of mathematical methods, astrophysical equations allow for an approximate estimate of the radius of an extrasolar planet based on the precisely obtained change in the luminous flux for a candidate star and the size of the star (the star's radius is known in advance based on the known value of the star's luminosity and temperature, the so-called spectroscopic classification). an example of work on the detection of exoplanets was like this [7], [8], [9]. preparations involved the following (repeateble) procedures. a. collection of available data:  defining candidate extrasolar planets for analysis.  preparation for astrophotography of the candidate star (collection of data on the position (coordinates) and parameters of the star (type of star, mass, temperature, radius).  determining the date and exact time of the transit of an extrasolar planet (ephemeris for exoplanets).  example of an exoplanet search archive:  nasa exoplanet archive: http://exoplanetarchive.ipac.caltech.edu/cgi–bin/transitview/nphvisibletbls?dataset=transits.  exoplanet transit database (etd) website:http://var2.astro.cz/etd/predictions.php.  extrasolar planet transit finder:http://jefflcoughlin.com/transit.html  aavso's variable star index (vsx),https://vsx.aavso.org/  encyclopaedia of exoplanetary systems,https://exoplanet.eu/home/. b. recording the images:  going to the field (a place with less light pollution) and night shooting of candidate stars.  setting up the equatorial mount.  precise northing of the assembly to the northern sky.  setting up the main telescope and weights for proper mounting balance.  setting up an auxiliary telescope (finder) to guide the assembly (in recent times, astro cameras are used that have a special sensor inside the housing that is used for guidance).  placing an additional (e.g. planetary) camera on the auxiliary telescope, with the help of which the telescope will be positioned on one fixed star guidance. in this way, it is possible to properly track (and cancel) the rotation of the earth without star trails in images with longer exposures.  installing an astronomical ccd camera on the main telescope, which will record the brightness of the candidate star. recording one star in just one night, if successful, takes at least 4-5 hours. in addition to the recording process, additional calibration images (dark, flat frames) are taken to reduce noise and vignetting in the images, as well as calibration images to reduce the overall measurement error.  care should be taken when a meridian flip occurs (applies to all equatorial mounts). in the event of a flip, the shooting preparation process is repeated. c. data processing and analysis: after the recording, data processing is initiated. the resulting images are processed using the software (differential photometry) by exactly determining the intensity of the candidate star's light flux in each of the images (several hundred images can be taken in one night). it is necessary to perform proper calibration of the images with dark, flat and bias frames using software. after estimating the intensity of the light flux for a given star, further data processing is performed using software, whereby a diagram of the change in the light flux of a given star for a certain time period (transit period) is defined. based on the diagram of the candidate star's light flux, if the measurement was accurate, the existence of an extrasolar planet around the given star is confirmed. dss vol. 6, no. 2, 2025, pp.142-157 148 the analysis of planet parameters is done using astrophysical models, where the size of the planet is determined, and if additional kinematic parameters for the star are available (e.g., radial velocity of the star), the inclination of the planet's path to the sun, as seen from earth, can also be determined. in case of failure of the recording for a particular night, after identifying the problem, the entire procedure should be repeated on another night, where it is important that it is clear and the atmosphere is as clean as possible. the aforementioned procedure is repeated every time a particular candidate star is recorded. preparing the equipment for one recording takes 2-3 h. most spring and summer days are used for recording. it is also necessary that the weather is clear, without the moon in the night sky (or that it is not in its full phase), which further reduces the number of effective days for measurement. for additional details, we recommend following references [7], [8], [9]. 4. estimation of the parameters of the exoplanet wasp-10b wasp (wide angle search for planets) is an international consortium of several academic organizations conducting an ultra-wide-angle search for exoplanets using the transit photometry method. an array of robotic telescopes aims to survey the entire sky, simultaneously observing thousands of stars of apparent magnitude 713. wasp is essentially an exoplanet discovery programme made up of the isaac newton group, the iac and six universities in the uk. two continuously operating, robotic observatories cover the northern and southern hemispheres. superwasp-north is located at the roque de los muchachos observatory on the mountain of the same name that dominates la palma in the canary islands. wasp-south is located at the south african astronomical observatory, sutherland in the arid roggeveld mountains of south africa. they use eight wideangle cameras that simultaneously scan the sky for planetary transit events and simultaneously allow the observation of millions of stars, allowing the detection of rare transit events. 4.1 the star wasp-10 and the planet wasp-10b wasp-10 is a star in the direction of the constellation pegasus. figure 2 shows the currently known parameters of the star. figure 3 shows the known parameters of exoplanet wasp-10b. fig. 2 parameters of star wasp-10 [10] fig. 3 parameters of exoplanet wasp-10b [11] dss vol. 6, no. 2, 2025, pp.142-157 149 the star wasp-10 is about 22% smaller than the sun, and has a mass about 30% less than the sun's mass. it is classified as a k5 star, with a surface temperature of around 4675k less than that of the sun. it is about 460 light years away from us and cannot be seen with the naked eye because its magnitude is 12.7. it is about 270 million years old [12] and represents a relatively young star. it takes about 12 days for one revolution around its axis. the only confirmed planet around this star is wasp-10b, which was discovered in 2008. the exoplanet wasp-10b is an extrasolar planet discovered in 2008 by superwasp using the transit photometry method. additional radial velocity observations have shown that the planet is about three times more massive than jupiter, while transit observations have shown that its radius is 8–28% larger than jupiter's (1.08 to 1.28 jupiter radii), relatively small for a hot jupiter. the planet has a density similar to that of our moon, and its surface temperature is about 1300 k. it takes about 3 days to orbit its star (compared to the 365 days it takes for the earth to orbit the sun). it is the only confirmed extrasolar planet in the wasp-10 planetary system, as the only other discovered planet in this planetary system, wasp-10c, is still unconfirmed [11]. figure 4 shows the star wasp-10, in a field of view with an angular width of 15'x15′. fig. 4 star wasp-10 in constellation pegasus (digitized sky survey, dss) dss vol. 6, no. 2, 2025, pp.142-157 150 figure 5 shows the light curve determined by differential photometry for wasp-10b [13]. fig. 5. light curves for four transits of wasp-10 b with models based on the solution obtained for run 4 data and employing the quadratic limb darkening law. the residuals are shown in bottom plots. [13] table 1 gives the parameters of the planet wasp-10b (various authors), determined by modeling the light curve obtained by photometry. table 1. physical properties of the wasp-10 system derived from light-curve modeling. literature determinations are cited for comparison. [13] researches focused on studying the exoplanet wasp-10b can be found in references [17-32]. christian et al. [32] present the original discovery and characterization of wasp-10b, identifying it as a ~3 mj gas giant transiting a late-type k star. the authors provide the first measurements of mass, radius, orbital parameters, and stellar properties. the authors in [18] examine the role of tidal friction in driving orbital decay among ultra-short-period planets. by modeling tidal dissipation within both the star and planet, the study finds that frictional evolution significantly affects orbital stability, potentially leading to rapid inward migration and eventual planetary engulfment. their results constrain the lifecycle of close-in exoplanet systems. the paper [19] evaluates how clouds increase atmospheric opacity and thereby affect the inferred metallicity of giant exoplanets. through dss vol. 6, no. 2, 2025, pp.142-157 151 atmospheric modeling, the authors demonstrate that neglecting cloud opacity can lead to underestimation of heavy-element content. the study emphasizes the need for cloud-inclusive models when interpreting observational spectra. the work in [20] explores pulsating low-mass white dwarfs, mapping the instability strip of pre-elm (extremely low-mass) white dwarfs. by coupling stellar evolution models with pulsation analyses, the authors identify regions in parameter space where pulsations occur, providing constraints on internal structure, mass loss, and binary evolution pathways. the observational paper [21] presents transit photometry for five exoplanets (hat-p-12b, hat-p-13b, hatp-16b, hat-p-23b, and wasp-10b) obtained at the universidad de monterrey observatory. the study refines transit parameters such as depth, duration, and timing, demonstrating the capability of small-scale observatories to contribute precise exoplanet measurements. basturk et al. [22] report on defocused transit observations using the 1-m t100 telescope at tübi̇tak national observatory. defocusing reduces systematic noise and improves photometric precision. the study presents refined transit curves for selected exoplanets, validating the technique for high-accuracy ground-based photometry. kammer et al. [23], using spitzer infrared data analyzed secondary eclipses of five cool gas giant planets, deriving atmospheric emission properties. the authors identify empirical trends in thermal emission spectra, providing insights into atmospheric composition, temperature distributions, and radiative processes in cool giant exoplanets. cruz et al. [24] report the detection of the secondary eclipse of wasp-10b in the ks-band, offering one of the few ground-based measurements of thermal emission for this system. the results constrain the planet’s dayside temperature and atmospheric properties. maxted et al. [25] investigated wasp-1628+10, an el cvn-type binary containing a very-low-mass stripped red giant. through photometry and spectroscopy, the authors identify multi-periodic pulsations and model the evolutionary history of the system, informing the understanding of binary evolution and stellar stripping processes. barros et al. [26] examined transit timing variations (ttvs) in wasp-10b, exploring whether stellar activity can mimic ttv signals. the authors show that starspot occultations significantly influence timing measurements, emphasizing the need to correct for magnetic activity when interpreting ttvs. husnoo et al. [27] provided observational constraints on tidal effects by analyzing the orbital eccentricities of exoplanet systems. the authors find correlations between eccentricity and tidal circularization timescales, contributing to understanding of tidal dissipation efficiencies in close-in planetary systems. maciejewski et al. [28] studied transit timing variations and stellar activity in the wasp-10 system, presenting high-precision light curves and refined system parameters. the results suggest that starspots and magnetic activity significantly affect observed transit times, complicating interpretations of potential additional planets. dittmann et al. [29] present transit observations of wasp-10b obtained with ground-based telescopes, yielding improved photometric precision. the authors refine physical parameters such as transit depth and orbital inclination, contributing to the early characterization of this planetary system. krejcova, budaj & krushevska [30] give a short observational report documenting photometric measurements of wasp-10b, confirming transit depth and duration. the paper supports previous detections and validates observational methods for small telescopes. johnson et al. [31] in their study revised the radius of wasp-10b, showing it to be smaller than previously estimated based on improved light-curve analysis. the findings suggest a denser structure and prompt reevaluation of the planet’s internal composition and formation history. the study [32] investigates how cloudy atmospheres influence the long-term thermal evolution of warm giant exoplanets. using interior modeling, the authors show that clouds act as an additional insulating layer, altering cooling rates and modifying the planets’ observable radii and luminosities. the work highlights the importance of atmospheric opacity in interpreting mass–radius relationships for giant planets. 4.2 recording of wasp-10b and estimation of its parameters the imaging and estimation of the parameters of the exoplanet wasp-10b within the framework of this work was carried out as follows, in accordance with the recommendations given in chapter 3. preparation. collection of available data, namely:  defining an extrasolar planet (candidate) for analysis.  preparation for photometry of the candidate star (collection of data on the position (coordinates) and parameters of the star (star type, mass, temperature, radius).  determining the date and exact time of the transit of an extrasolar planet (ephemeris for exoplanets).  searching the online archives. dss vol. 6, no. 2, 2025, pp.142-157 152 recording.astrophotographic recording of a candidate star, with the aim of detecting extrasolar planets around it using the transit method (reduction in the intensity of the light flux of the star when the planet passes in front of its disk). surface uniform luminous flux of the observed star is assumed. the recording consisted of the following procedures:  setting up and verifying the installation of sw eq6.  setting up the main telescope, sct 8″, and the auxiliary telescope (9x50mm) through which guidance was performed.  mounting the qhy-5lii guidance camera on the auxiliary telescope.  mounting the ccd atik 383 l+ mono camera on the main telescope.  setting up the sgpro program for recording (finding a star using coordinates, setting the number and type of frames, setting camera and telescope parameters).  recording calibration frames (bias, dark, and flat frames) which are used to remove noise from images, hot pixels, and thermal signal, as well as vignetting of images.  lightly defocus the stars (preferably 5-10 pixels).  precise time synchronization on a laptop (e.g. with dimension 4).  recording 120 images (monochrome images in fits format) of the wasp-10 star, taking into account the beginning and end of the transit. it is also necessary to record at least half an hour before and after the transit. based on the images of the candidate star, an analysis of the star's brightness for a certain time period (the planet's transit period) is performed. the exposures were 90 seconds (care should be taken that the star is not oversaturated ("burned out"), so the maximum adu (analog-to-digital unit) was at about 70% of the maximum.  care should be taken when the meridian flip occurs (applies to all equatorial mounts). in the case of a flip, the images are inverted. this is corrected later when aligning the images. calibration (and star alignment) of recordings. calibration of star images with bias, dark, and flat frames was performed in software. after that, the alignment of the stars was done so that all frames were exactly the same. note that there is no vignetting in image (fig. 6), which is very important in photometry. fig. 6 appearance of the calibrated and star-aligned image showing the star wasp-10 (in the center) dss vol. 6, no. 2, 2025, pp.142-157 153 differential photometry method. the method involves the analysis of all images, where the intensity of the luminous flux from the observed star is analyzed for the entire time of the transit of the extrasolar planet. the shape of the luminous flux curve generally depends on the ratio of the radius of the planet and the central star, the latitude of the transit over the parent star, and the darkening of the edges of the stellar disk (so-called limb darkening). the astroimagej software (fig. 7) was used, which allows very precise differential photometric measurements of the star for each measurement performed. the program [16] also allows exporting the obtained data on the intensity of the luminous flux. many scientific papers have been written using this program. fig. 7 the candidate star (green circle) and several nearby reference stars (red circles) in the astroimagej software. if one wants to determine the magnitude of a candidate star, one must also define the magnitudes of the reference stars used in the photometry. a good tool for selecting these stars is the aavso's variable star plotter (vsp) utility. data processing and regression analysis. these methods involve graphical representation and modeling of the change in the luminous flux for a candidate star in a certain time interval, based on the images. regression analysis of the obtained data defines the function of the change in the luminous flux intensity of a given star during the transit of an extrasolar planet. the data were processed (modeled, fitted) in the astroimagej software (fig. 8). in this, we had the help of prof. dr. john kielkopf (professor of physics and astronomy at the university of louisville), one of the authors of the astroimagej program [14]. dss vol. 6, no. 2, 2025, pp.142-157 154 fig. 8 our modeling of the transit curve is based on the relative flux data (the candidate star's flux compared to the flux of the surrounding reference stars). note that the drop in light intensity is only about 1%! mathematical methods. astrophysical equations allow us to approximately estimate the radius of an extrasolar planet, as well as some other parameters of the planet, based on the precisely obtained change in the luminous flux for the candidate star and the size of the star (the star's radius is known in advance based on the known value of the star's luminosity and temperature, the so-called spectroscopic classification). the exoplanet transit model used to estimate its parameters in the astroimage j program is based on the model from the work of mandel & agol [15]. here, the transit is modeled as an eclipse of a spherical star by a spherical planet with an opaque atmosphere. the model is parameterized with several physical parameters (plus the light flux f0), namely: the ratio of the planet's radius to the star's radius rp/r*, the ratio of the semi-axis of the planetary orbit to the star's radius a/r*, the time of the middle of the transit tc, the transit parameter would be the parameters u1 and u2 of the quadratic model of star edge obscuration. based on these parameters, the inclination of the planet can also be determined. in our case, we obtained an inclination of the planet of 89°, while the literature mentions a value of 86.8°-89.5°. we also obtained that the radius of the planet is 1.12 jupiter's radius, which is a result of sufficient accuracy for amateur measurements, since in the literature this value ranges from 1.08 to 1.28 jupiter's radius. also, based on our data and the model used [15], we obtained (fig. 9) that the ratio of the semi-axis of the planetary orbit to the radius of the star a/r* is equal to 22.6 (which means that the radius of the orbit of the planet wasp-10b is about 0.079 au), and the value for this ratio circulating in the literature is 10.2 12.1 (the radius of the planet's orbit is about 0.041 au). dss vol. 6, no. 2, 2025, pp.142-157 155 fig. 9 our application of the mandel & agol [15] model in astroimagej to determine the key parameters of the planet wasp-10b based on the obtained data. in the upper part of fig. 9, it can be seen that the input parameters of the model, apart from the imaging data, are known data about the star wasp-10b. e.g., based on the mass of the star and its class, other parameters of the star can be determined (upper part of figure 9). also, the transit period (3.0927616 days) must be entered as input data. conclusions the paper explains the method of differential photometry with the aim of determining the parameters of exoplanets. the introductory part describes the basics of exoplanets, with a review of some of the more interesting planets discovered so far. also, the basics of practical amateur differential photometry are described, with a review of the necessary equipment and software. the techniques used to estimate the main parameters of the exoplanet wasp-10b are described. based on the imaging and data processing, the planet's inclination was obtained to be 89° (the literature mentions a value of 86.8°-89.5°). also, the planet's radius was estimated to be 1.12 jupiter radii (the literature mentions this value as 1.08 1.28 jupiter radii). based on our data and the model used [15], we obtained that the ratio of the planetary orbital semi-axis to the star's radius a/r* is equal to 22.6 (which means that the orbital radius of the planet wasp-10b is about 0.079 au), and the value for this ratio circulating in the literature is 10.2 12.1 (the planetary orbital radius is about 0.041 au). the described method is an interesting way for amateur astronomers to contribute to the astronomical community, but it is also a useful learning tool, especially for younger generations who are interested in the universe around us. references: [1] m. perryman, the exoplanet handbook. cambridge, uk: cambridge university press, 2011, https://doi.org/10.1111/maps.13308. [2] nasa, “nasa’s tally of planets outside our solar system reaches 6,000,” nasa, sep. 17, 2025. [online]. available: https://www.nasa.gov/universe/exoplanets/nasas-tally-of-planets-outside-our-solarsystem-reaches-6000/ [3] nasa, “exoplanets,” nasa, [online]. available: https://science.nasa.gov/exoplanets/ dss vol. 6, no. 2, 2025, pp.142-157 156 [4] the extrasolar planets encyclopaedia, “home,” [online]. available: https://exoplanet.eu/home/ [5] d. bansal, d. cody, c. herrera, d. russell, and r. m. campbell, “light curve analysis for transit of exoplanet qatar-1b”, baylor university department of astrophysics, 2015. [6] an amateur detecting exoplanets, costablancaastronomers.wordpress.com, nov. 12, 2016. [online]. available: https://costablancaastronomers.wordpress.com/2016/11/12/an-amateur-detecting-exoplanets [7] d. m. conti, aavso exoplanet observing manual – revision 1.1, the american association of variable star observers (aavso). [online]. available: https://www.aavso.org/sites/default/files/publications_files/aavso%20exoplanet%20manual%20rev. %201.1.pdf [8] d. m. conti, a practical guide to exoplanet observing, revision 5.3, sep. 2024. [online]. available: https://www.astrodennis.com/guide.pdf [9] b. l. gary, exoplanet observing for amateurs, reductionist publications, 2007. [online]. available: https://brucegary.net/book_eoa/eoa.pdf [10] aavso, “variable star plotter (vsp),” aavso, [online]. available: https://apps.aavso.org/vsp/ [11] “wasp-10,” wikipedia. [online]. available: https://en.wikipedia.org/wiki/wasp-10 (accessed nov. 27, 2025). [12] “wasp-10b,” wikipedia. [online]. available: https://en.wikipedia.org/wiki/wasp-10b (accessed nov. 27, 2025). 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[33] s. hadden et al., “toi-4600 c: a long-period gas giant from tess,” astrophysical journal letters, vol. 958, no. 2, l9, 2023. doi: 10.3847/2041-8213/ad14f8. microsoft word findik paper review.docx (online) issn 2744-1741 defense and security studies original research vol. 6, no. 2, 2025, pp.132-141 https://doi.org/10.37868/dss.v6.id291 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 132 recent developments in ballistics erdal camci1, fehim findik2,3* 1 arifiye vocational school, sakarya applied sciences university, sakarya, turkey 2 metallurgy and materials engineering department, faculty of technology, sakarya applied sciences university, sakarya, turkey 3 istanbul aydın university, mechanical eng dept, engineering faculty, florya halit aydın campus, istanbul, turkey *corresponding author e-mail: findik@subu.edu.tr received: sep. 10, 2025 revised: nov. 8, 2025 accepted: nov. 26, 2025 online: nov. 26, 2025 abstract ballistics, the science of projectile motion, encompasses the study of objects such as bullets, missiles, and rockets from launch to impact, divided into internal, external, terminal, and forensic ballistics. this paper explores recent advancements in ballistic materials, methods, and sustainability challenges. traditional and selfhealing materials, including microcapsule-based, bio-inspired, and metallic selfrepairing systems, are examined for their applications in armor, projectiles, and thermal protection. experimental techniques like light gas guns and high-speed photography, alongside numerical simulations such as finite element analysis (fea) and smoothed particle hydrodynamics (sph), are compared for their efficacy in ballistic research. highvelocity projectiles exceeding mach 5, including hypersonic and kinetic energy penetrators, are analyzed for their aerodynamic and material challenges, with future directions pointing toward ai-guided systems and 3d-printed materials. the study also highlights green ammunition innovations, such as lead-free bullets and biodegradable cartridges, to address environmental concerns like toxic propellants and heavy metal contamination. sustainability efforts focus on resource efficiency, including recycled composites and additive manufacturing, while military and civilian applications explore hypersonic swarms and non-lethal munitions. the paper concludes with future perspectives, emphasizing digital twins in forensics, space ballistics, and closed-loop ammunition recycling. by integrating experimental and computational approaches, this research aims to advance ballistic technologies while addressing ecological and ethical challenges in the field. © the author 2025. published by arda. keywords: ballistics, armor, projectiles, sustainability 1. introduction ballistics is the science of projectile motion, encompassing the behavior of objects such as bullets, missiles, and rockets from launch to impact. ballistics can be divided into three categories: internal ballistics, external dss vol. 6, no. 2, 2025, pp.132-141 133 ballistics, and terminal ballistics. internal ballistics examines the internal processes of a weapon, such as thrust, pressure, and muzzle dynamics. external ballistics examines the bullet's flight, trajectory, drag, and wind effects. terminal ballistics examines penetration, fragmentation, and tissue damage. types of ballistics can be categorized as interior ballistics, exterior ballistics, terminal ballistics, and forensic ballistics. the types of ballistics, focus areas, and key factors are shown in table 1. in addition, table 2 shows the application sectors, usage patterns, and sample technologies [1], [2]. ballistics studies are used in the military, forensics, aviation and space, and counterterrorism. for example, the use of self-guided sniper rounds in the military and the controlled landing of a spacecraft under changing aerodynamic forces in aviation are examples of ballistics [3], [4], [5], [6], [7]. in this study, traditional and self-repairing materials used in ballistic applications were examined. in addition, experimental and numerical simulation methods used in ballistic research were examined. then, the traditional and high-speed bullets used in ballistics were mixed. traditional and green ammunition, intelligent and guided ammunition were examined. the environmental effects encountered in ballistic sustainability and difficulties, such as resource efficiency, were examined in this research, and solutions to these difficulties were investigated. tables 1 and 2 below show types of ballistics, focus area, and key factors, as well as application areas, use cases, and example technologies investigated. table 1. types of ballistics, focus area, and key factors type focus area key factors internal inside the barrel propellant burn rate, pressure curves, barrel harmonics external projectile in flight drag coefficients, coriolis effect, gyroscopic stability terminal target impact penetration depth, energy transfer, wound ballistics forensic crime investigation bullet matching, gunshot residue (gsr) analysis table 2. application areas, use cases, and example technologies field use case example technologies military long-range sniping, missile guidance exacto smart bullets, hypersonic glide vehicles law enforcement crime scene reconstruction 3d bullet trajectory mapping (faro systems) aerospace rocket staging, re-entry vehicles spacex’s reusable rocket ballistics sports archery, shooting sports aerodynamic arrow designs, precision rifles medical ballistic trauma research fbi’s wound ballistics studies 2. materials various materials are used in ballistics. these materials can be divided into general materials and self-healing materials. here, we will examine the general materials as projectile materials, armor materials, cannon materials, and thermal protection materials [3], [4], [5]. 2.1 general detailed comparison tables of materials used in ballistic applications, including projectiles, armor, railgun components, and thermal protection systems, are provided below. projectile materials are listed in table 3, armor materials in table 4, railgun materials in table 5, and thermal protection materials in table 6. in table 3, projectile materials comparison is given for high-speed kinetic penetrators, hypersonic vehicles, and railgun slugs. in table 4, armor materials comparison is specified for defeating high-speed projectiles, fragmentation, and shaped charges. in table 5, railgun materials comparison is given for rails, armatures, and structural components in electromagnetic launchers. in table 6, thermal protection materials are conferred for hypersonic projectiles, reentry vehicles, and railgun components [1]. dss vol. 6, no. 2, 2025, pp.132-141 134 table 3. projectile materials comparison material density (g/cm³) melting point (°c) strength (mpa) advantages disadvantages applications tungsten carbide (wc) 15.6 2,870 500–1,200 extreme hardness, high density brittle, expensive apfsds rounds, penetrators depleted uranium (du) 19.1 1,132 1,000– 1,600 selfsharpening, pyrophoric toxic, radioactive tank penetrators titanium alloy (ti6al-4v) 4.43 1,650 900–1,100 lightweight, strong lower density than tungsten aerospace projectiles steel (4340 alloy) 7.85 1,425 1,000– 1,500 cost-effective, tough heavy, lower performance generalpurpose ammo carboncarbon composite 1.8–2.1 3,000 (sublimes) 200–500 (flexural) light, heatresistant low impact resistance hypersonic vehicle nose tips table 4: armor materials comparison material hardness (hv) density (g/cm³) advantages disadvantages applications rolled homogeneous armor (rha steel) 300–400 7.85 high toughness, cost-effective heavy, limited vs. du penetrators tanks, armored vehicles ceramic (al₂o₃, sic, b₄c) 2,500– 3,500 3.2–3.5 extreme hardness, lightweight brittle, multi-hit issues body armor, vehicle add-on uhmwpe (dyneema, spectra) 0.97 lightest armor, stops fragments weak vs. highvelocity ap bulletproof vests aramid (kevlar, twaron) 1.44 flexible, good for fragmentation degrades under uv/heat helmets, soft armor reactive armor (explosive sandwich) varies defeats shaped charges one-time use, dangerous to nearby troops tank protection table 5: railgun materials comparison material conductivity (ms/m) melting point (°c) advantages disadvantages applications copper (cu) 58 1,085 high conductivity low strength, erodes quickly traditional rails copperchromiumzirconium (cucrzr) 45–50 1,080 better wear resistance still erodes under plasma advanced railgun rails tungsten (w) 18 3,422 extreme durability poor conductivity, heavy rail liners grapheneenhanced copper ~60 (estimated) 1,085+ high conductivity, reduced wear expensive, experimental next-gen railgun rails plasma armature (aluminum plasma) n/a (ionized gas) no solid wear energy loss due to heat ultra-highspeed launches dss vol. 6, no. 2, 2025, pp.132-141 135 table 6: thermal protection materials material max temp. (°c) thermal conductivity (w/m·k) advantages disadvantages applications carbon-carbon (c/c) 3,000+ 50–150 (anisotropic) light, reusable expensive, oxidizes above 450°c in air hypersonic leading edges ultra-high-temp ceramics (zrb₂sic) 2,500+ 60–120 excellent ablation resistance brittle, hard to machine nose cones, scramjet parts tungsten (w) 3,422 170 extreme melting point heavy, oxidizes railgun projectiles phenolic impregnated carbon ablator (pica) 1,700+ 0.1–0.5 lightweight, ablative single-use, chars away spacecraft heat shields hafnium carbide (hfc) 3,900+ 20–30 highest known melting point extremely expensive experimental hypersonics 2.2. self-healing high-velocity projectiles, hypersonic vehicles, and spacecraft face extreme conditions. this is why, for example, hypersonic missiles experience temperatures of up to 3,000°f. similarly, microcracks form in railgun barrels and rocket nozzles due to repeated stress. therefore, materials that can autonomously repair damage are needed to extend lifespan. self-healing materials in ballistics can be divided into four categories: microcapsule-based healing, bio-inspired healing, intrinsic self-healing polymers, and metallic self-healing [3]. microcapsule-based healing uses small polymer capsules (50–200 µm) filled with healing agents such as dicyclopentadiene embedded in composites. when cracked, the capsules rupture, releasing polymerized liquid to seal the gaps. they are also used as heat shields in the thermal protection systems of spacex spacecraft and in self-healing coatings on weapon barrels to reduce wear. in bio-inspired healing, the mechanism mimics human blood vessels; hollow channels in the material deliver healing agents upon damage. for example, in military use, they prevent fatigue cracks in turbine blades in jet engines. in intrinsic self-healing polymers, reversible hydrogen bonds recombine under heat/light. for example, polyurethane-elastomer composites are used in missile wings. metallic self-healing involves the use of ni-ti shape-memory alloys, which fill cracks when heated. for example, self-healing metals are being tested for artillery shells [3]. 3. methods both experimental and numerical simulation methods are used in ballistic research. detailed comparison information covering the principles, advantages, limitations, and applications of experimental methods and numerical simulations used in ballistic research is provided in tables 7-9. it is seen from table 7 that experimental methods in ballistics, their description, advantages, disadvantages, and applications are given. numerical simulations in ballistics are also given, namely in table 8 via their definitions, advantages, limitations, as well as application areas. comparison of experimental vs. numerical approaches in ballistics is given in table 9, for different criteria, including cost, time, accuracy, scalability, as well as limitations. dss vol. 6, no. 2, 2025, pp.132-141 136 table 7: experimental methods in ballistics method description advantages limitations applications light gas gun (lgg) uses compressed hydrogen/helium to launch projectiles at mach 6+ extremely high velocities, controlled environment limited projectile size, single-shot hypervelocity impact studies, armor testing splithopkinson pressure bar (shpb) measures dynamic material properties under high strain rates accurate stressstrain data for materials limited to small samples, not fullscale penetrator/armor material characterization ballistic gel testing fired projectiles into calibrated gelatin blocks simulates tissue damage, standardized testing not fully representative of human tissue terminal ballistics, wound ballistics high-speed photography captures projectile flight/impact at >1,000,000 fps visualizes deformation, fragmentation expensive, requires precise timing fragment analysis, impact dynamics flash x-ray imaging x-ray pulses capture internal projectile/armor interactions sees through obscuration (smoke/debris) limited to a few frames, radiation hazards penetrator behavior behind armor doppler radar (e.g., weibel, radar) tracks projectile velocity and deceleration in flight real-time velocity data, long-range expensive, requires a clear line of sight exterior ballistics, drag coefficient validation table 8: numerical simulations in ballistics software/method description advantages limitations applications finite element analysis (fea) (e.g., ansys, ls-dyna) solves material deformation under impact using meshbased methods handles complex geometries, material nonlinearity computationally expensive, mesh dependency armor penetration, fragment simulation smoothed particle hydrodynamics (sph) meshless lagrangian method for extreme deformations no mesh distortion issues, good for fractures high computational cost, less accurate for elasticity hypervelocity impacts, explosive fragmentation computational fluid dynamics (cfd) (e.g., fluent, openfoam) models aerodynamics, shockwaves, and heat transfer captures hypersonic flow physics requires highfidelity turbulence models drag/wave drag optimization, thermal analysis molecular dynamics (md) simulates atomicscale interactions under impact reveals material failure mechanisms limited to nanoscale, extreme computational cost novel material design (e.g., graphene armor) coupled eulerianlagrangian (cel) combines fluid (eulerian) and solid (lagrangian) modeling ideal for fluidstructure interaction (e.g., shaped charges) complex setup, long solve times explosively formed penetrators (efps), blast effects discrete element method (dem) models granular materials (e.g., sand, ceramic fragmentation) simulates brittle fracture, particulate flow limited to granular systems, calibration needed ceramic armor failure, soil penetration dss vol. 6, no. 2, 2025, pp.132-141 137 table 9: comparison of experimental vs. numerical approaches criteria experimental methods numerical simulations cost high (equipment, ammo) lower (after software acquisition) time slow (setup, repetition) faster (parametric studies) accuracy high (real-world physics) depends on model fidelity scalability limited (physical constraints) highly scalable (virtual prototypes) data output direct measurements (e.g., velocity, damage) full-field data (stress, temp., etc.) limitations safety risks, material costs requires validation, assumptions best for validation, terminal effects parametric optimization, conceptual design 4. high-speed projectiles in ballistics, high-velocity projectiles refer to objects launched at speeds significantly higher than conventional ammunition, typically exceeding 1,700 m/s (mach 5). these projectiles are analyzed for internal ballistics (inside the weapon), external ballistics (flight dynamics), and terminal ballistics (impact effects) [4], [5]. high-velocity projectiles can be divided into hypersonic projectiles, kinetic energy penetrators, and hypervelocity impactors. hypersonic projectiles are used in advanced military applications such as railguns and scramjet-assisted projectiles. kinetic energy penetrators are used in tank ammunition, such as armor-piercing and finned projectiles. hypervelocity impactors are used in space exploration. high-speed projectiles present challenges such as aerodynamic heating, drag, and stability. for example, at speeds of mach 5+, air friction causes extreme temperatures (1,000-3,000°c), requiring advanced materials such as tungsten, ceramic, or carbon composites. shock waves also disrupt flight; specialized shapes, such as thin nose cones, improve efficiency. furthermore, spin stabilization can fail; fins or homing systems are typically used. propulsion methods such as chemical thrusters and electromagnetic railguns are used to address these challenges. high-velocity projectiles can be used in military and civilian applications. for example, these high-velocity projectiles are used in military applications, long-range precision-strike hypersonic missiles, and to penetrate modern tank armor. in space and science, high-velocity projectiles are also used to simulate high-velocity impacts on satellites and to test asteroid deflection via hypervelocity impact. future developments of high-velocity projectiles can be envisioned as follows: the use of guided hypersonic projectiles for ai-assisted mid-range corrections, the use of energy-efficient railguns to overcome power and barrel wear issues, and the use of 3d-printed materials to develop heat-resistant alloys for sustained hypersonic flight [1], [2]. 5. ammunition ammunition is a term that encompasses all spare parts and ammunition necessary for warfare that are not fixed assets. ammunition, on the other hand, is any explosive or penetrating material prepared for firing from firearms. there are many different types of ammunition. this section will focus solely on green ammunition and smart ammunition. green ammunition is used in environmentally friendly ballistics to reduce toxicity, pollution, and resource consumption in firearms and artillery. green ammunition includes lead-free bullets, biodegradable cartridges, and clean propellants. lead poisoning harms wildlife and contaminates shooting ranges. non-toxic w-cu alloys, lightweight polymercomposite bullets, and ammunition that fragments on impact and does not ricochet can be used as solutions. these are examples of lead-free ammunition. brass/steel cartridges take decades to decompose. this creates environmental pollution. biodegradable cartridges can be used as a solution to this problem. examples of this include pha-based polymers and seedembedded hives. pha-based polymers decompose within 1-2 years, and seed-embedded hives are destroyed and then planted. nitrocellulose gunpowder emits carcinogenic substances. alternatively, nitroamine-based propellants, which have lower toxicity and higher energy efficiency, are used, or electric ignition, which eliminates the chemical encapsulation. dss vol. 6, no. 2, 2025, pp.132-141 138 smart and guided munitions can be divided into two categories: self-guided projectiles and ai-assisted targeting. self-guided projectiles have demonstrated real-time course correction. self-guided projectiles have demonstrated real-time course correction. machine learning increases hit probability for snipers and artillery by taking into account wind, humidity, and target movement. machine learning, used in ai-assisted targeting, increases hit probability for snipers and artillery by accounting for wind, humidity, and target movement. 6. sustainability the field of ballistics is facing increasing scrutiny regarding environmental impact, resource efficiency, and ethical concerns, while also advancing with the latest technologies. below is a breakdown of sustainability challenges [4], [5]. sustainability challenges in ballistics can be divided into two categories: environmental impacts and resource efficiency. environmental impacts include toxic propellants, heavy metals, and ammunition contamination. for example, traditional gunpowder (nitrocellulose) and lead-based bullets contaminate soil/water. green ammunition, known as lead-free bullets (w or cu composites), could be used as a solution. biodegradable cartridges (plant-based polymer cartridges) could also be a potential solution. ammunition pollution is another factor affecting the environment. unexploded ordnance, such as landmines and artillery shells, damages ecosystems. research is underway on self-degrading mines as a solution to this problem. furthermore, ai-powered cleaning drones are being used to detect and destroy old ammunition. another challenge in sustainability is resource efficiency. resource efficiency can be explored in terms of rare earth material dependency and energy-intensive systems. tungsten is a combat material used in armor-piercing projectiles. as an alternative to this heavy metal, some recycled composites, such as depleted uranium alternatives, can be used. additive manufacturing (3d printing) can also be used to reduce waste in projectile production. rail guns and hypersonic missiles also require tremendous power. energy sources such as portable fusion reactors are being explored as alternative solutions [8], [9]. 7. future perspectives future perspectives and innovations can be briefly examined in four groups: military and defense, forensics and law enforcement, space and aviation, and civilian applications [6], [7]. various trends, their application examples, and sustainability angles for military and defense are shown in table 10. table 10. military & defense applications and sustainability trend example sustainability angle hypersonic swarms ai-coordinated micro-missiles reduced collateral damage energy weapons laser interceptors (e.g., helios) no physical ammunition waste bio-inspired design shape-changing projectiles (darpa) improved aerodynamics = less fuel use forensics and law enforcement, topics such as digital twins and non-lethal smart munitions can be discussed. in preparing digital twins for crime scene problems and supporting critical decision-making processes, 3d simulated bullet trajectories reduce laboratory waste. furthermore, fatalities can be minimized by using electroshock bullets, a type of non-lethal smart munition. in space and aviation, research is underway for future use in self-orbiting satellites and planetary defenses [10], [11]. finally, for civilian applications, sustainable hunting ammunition and sport shooting can be discussed. regarding sustainable hunting ammunition, it can be noted that federal's non-toxic shot (steel/bismuth shot) is gradually replacing lead. furthermore, studies on the construction of solar-powered shooting ranges and the use of recycled brass materials in sport shooting can be reported. various areas, including green ammunition, space ballistics, and sustainability, are shown in table 11 between 2025 and 2030 as well as beyond 2030 [4], [5], [6], [7], [8], [12], [13]. table 11. future outlook for different areas between 2025 and 2030. area 2025–2030 beyond 2030 green ammo mandatory lead bans (eu/nato) bio-fabricated "living bullets" space ballistics hypersonic missile treaties lunar railgun launches pads sustainability range cleanup drones closed-loop ammo recycling dss vol. 6, no. 2, 2025, pp.132-141 139 recently, experimental and numerical investigations have been done about the ballistic impact on polymerbased composite materials as well as metallic systems [14], [15], [16], [17], [18]. in polymeric-based composite metals [14], [15], various guns were used from a certain distance to the target, and their impact performance was determined (figure 1). also, various design in metallic systems (figure 2) was employed and their impact performance was investigated via experimental as well as numerical systems [16], [17]. it is predicted that some more investigations can be done about the ballistic impacts of different materials and composites to better understand of the ballistic performance via experimental as well as numerical studies. fig. 1 an illustration of deformed bullets following a firearm test [15] fig. 2 cad model of the armor system designed using creo parametric software [16] dss vol. 6, no. 2, 2025, pp.132-141 140 8. conclusions the following conclusions can be drawn from the previous investigation for ballistic perspectives:  ballistics is the science of projectile motion, encompassing the behavior of objects such as bullets, missiles, and rockets from the moment of launch to the moment of impact. ballistics studies are used in military, forensic science, aviation and space, and counterterrorism. the use of self-guided sniper rounds in the military and the controlled descent of a spacecraft under changing aerodynamic forces in aviation are examples of ballistics.  to extend the lifespan of ballistics, self-healing materials are needed. these materials can be divided into four categories: microcapsule-based healing, bio-inspired healing, intrinsic self-healing polymers, and metallic self-healing.  both experimental and numerical simulation methods are used in ballistic research. the experimental methods used in ballistic research are very informative, but they require a long time to prepare the materials, and these materials are quite expensive. therefore, it is recommended to model the study in a virtual environment before the experiment and solve it in a simulation environment using various methods such as fem.  in ballistics, high-velocity projectiles refer to objects launched at speeds significantly higher than conventional ammunition, typically exceeding 1,700 m/s (mach 5). these projectiles are analyzed for internal ballistics (inside the weapon), external ballistics (flight dynamics), and terminal ballistics (impact effects). high-velocity projectiles can be classified as hypersonic projectiles, kinetic energy penetrator projectiles, and hypervelocity impactor projectiles.  ammunition is any explosive or penetrating substance designed to be fired from a firearm. green ammunition is used in environmentally friendly ballistics to reduce toxicity, pollution, and resource consumption in firearms and artillery. green ammunition includes lead-free bullets, biodegradable cartridges, and clean propellants. smart and guided munitions can be divided into two categories: selfguided projectiles and ai-assisted targeting. self-guided projectiles have demonstrated real-time course correction.  sustainability challenges in ballistics can be divided into two categories: environmental impacts and resource efficiency. environmental impacts include toxic propellants, heavy metals, and ammunition contamination. green ammunition, also known as lead-free ammunition (w or cu composites), can be used as a solution. ammunition contamination is another factor affecting the environment. unexploded ordnance, such as landmines and artillery shells, damages ecosystems. research is ongoing on selfdestructing mines as a solution to this problem.  in forensics, preparing digital twins for crime scene problems and supporting critical decision-making processes, 3d-simulated bullet trajectories reduce laboratory waste. furthermore, fatalities can be minimized by using electroshock bullets, a type of non-lethal smart ammunition. examples include sustainable hunting ammunition for civilian applications and sport shooting. it's worth noting that nontoxic shot (steel/bismuth shot) is increasingly replacing lead when it comes to sustainable hunting ammunition. declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. dss vol. 6, no. 2, 2025, pp.132-141 141 references [1] defense advanced research projects agency (darpa), “hawc: hypersonic air-breathing weapon 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[18] e. camci and f. findik, “ballistic impact performance of laminated composite structures,” periodicals of engineering and natural sciences, vol. 7, no. 3, pp. 1394-1344, 2019, doi: 10.21533/pen.v7i3.700. microsoft word review of design parameters and optical characteristics of main types of amateur telescopes (online) issn 2744-1741 defense and security studies original research vol. 6, no. 1, 2025, pp.49-90 https://doi.org/10.37868/dss.v6.id287 this work is licensed under a creative commons attribution license (https://creativecommons.org/licenses/by/4.0/) that allows others to share and adapt the material for any purpose (even commercially), in any medium with an acknowledgement of the work's authorship and initial publication in this journal. 49 review of design parameters and optical characteristics of the main types of amateur telescopes alan ćatović*1, džan jašarević1 1 mechanical engineering faculty, university of sarajevo, bosnia and herzegovina *corresponding author e-mail: catovic@mef.unsa.ba received: mar. 30, 2025 revised: may 20, 2025 accepted: may 25, 2025 online: may 27, 2025 abstract this review examines the design principles and image quality performance of the three primary types of amateur astronomical telescopes: refractors, reflectors, and catadioptrics. the study begins with a thorough overview of existing literature, referencing over 150 sources to provide a theoretical introduction for the analysis. each telescope type is evaluated in terms of its optical construction, aberration control, portability, maintenance, and suitability for both visual observation and astrophotography. key differences and trade-offs in performance, usability, and cost are discussed. special attention is given to how each design handles chromatic and spherical aberrations, field curvature, and diffraction effects factors critical to image sharpness and contrast. the paper concludes with practical recommendations tailored to various user needs, such as planetary observation, deep-sky imaging, or beginner-level stargazing. by synthesizing theoretical insights with practical considerations, this review aims to guide amateur astronomers, educators, and enthusiasts in selecting the most appropriate telescope type for their specific interests and observing goals. © the author 2025. published by arda. keywords: astronomical telescope; optical design; refractor; reflector; catadiopter 1. introduction astronomical telescopes have played a crucial role in expanding our understanding of the universe, enabling observations from the visible spectrum to infrared and radio wavelengths. over the centuries, telescope designs have evolved significantly from early refractors and reflectors to sophisticated space-based observatories equipped with adaptive optics and segmented mirrors. each design is driven by scientific requirements, such as improved resolution, greater light-gathering power, and minimized optical aberrations. astronomers rely on three main types of telescopes: refracting, reflecting, and catadioptric systems. each design has distinct optical characteristics that influence image quality, such as resolution, contrast, and the correction of various aberrations. this paper examines the fundamental principles behind these telescope types and analyzes their performance in both visual observation and astrophotography. consideration is given not only to optical performance but also to practical aspects like portability, ease of use, maintenance, and cost. drawing on a broad range of literature, the paper offers a comparative overview aimed at helping users understand the advantages and limitations of each design. based on this analysis, recommendations are provided in selecting the most appropriate telescope for specific observational needs. dss vol. 6, no. 1, 2025, pp.49-90 50 2. review of literature a substantial body of literature exists on the design and development of astronomical telescopes, encompassing both academic publications and practical manuals. numerous high-quality books are available that explore the theoretical foundations and engineering aspects of telescope construction. these resources can generally be categorized into two distinct groups: those that address the complex requirements and design methodologies of professional observatory-class telescopes, and those that serve as practical guides for amateur telescope makers. while the former often delves into advanced optical theory, precision engineering, and large-scale instrumentation, the latter typically focuses on simplified construction techniques, costeffective materials, and performance optimization for personal or hobbyist use. in addition to books, a wide range of peer-reviewed scientific articles contributes to the field by presenting original research, case studies, and technical innovations in telescope optics, mechanical design, and performance analysis. these papers provide valuable insights into recent advancements in optical materials, aberration correction techniques, and adaptive optics systems. the diversity of topics covered in the literature reflects the ongoing evolution of telescope technology and the broad interest it holds for both professional astronomers and dedicated amateurs. this study incorporates a curated selection of these resources, with over 150 references reviewed to ensure a comprehensive understanding of current trends and foundational concepts in telescope design. the literature survey not only highlights the historical progression of various telescope types but also identifies key contributions that have influenced the design principles of modern amateur telescopes. through this extensive review, the paper aims to bridge the gap between theoretical knowledge and practical application, providing a solid contextual framework for the comparative analysis that follows. 2.1 review of books "the history of the telescope" by henry c. king [38] is a comprehensive chronicle detailing the development of the telescope from its invention through the mid-20th century. originally published in 1955, this work delves into the contributions of renowned figures, such as galileo, newton, and huygens, and lesser-known craftsmen and amateurs who played pivotal roles in advancing telescope technology. king's narrative is enriched by nearly 200 illustrations, including portraits, diagrams, and photographs, offering readers a visual journey through the evolution of astronomical instruments. the book is praised for its detailed scholarship and accessibility, making it a valuable resource for both enthusiasts and scholars interested in the history of astronomy and optical science. cheng in his book [1] offers a comprehensive exploration of telescope design across the electromagnetic spectrum, including radio, infrared, optical, x-ray, and gamma-ray wavelengths. drawing from over twentyfive years of experience, cheng provides both a general introduction and an in-depth theoretical analysis of telescope design. the book is structured into several chapters, each focusing on different aspects of telescope design. bely [2] offers a comprehensive resource that consolidates the astronomical and engineering principles essential for designing and building large telescopes. published in 2003 as part of the astronomy and astrophysics library series, the book addresses various aspects of telescope development, from fundamental astronomical observations to detailed engineering considerations. rutten and van venrooij’s [3] excellent book explains the principles and practicalities of telescope design and performance, tailored specifically for amateur astronomers. first published in 1988, this book serves as both an educational resource and a reference manual. schroeder’s [4] book is a comprehensive text that delves into the fundamental principles and applications of optical design in astronomy. the book offers a unified treatment of various types of telescopes, addressing both those influenced by geometrical aberrations and atmospheric effects, as well as diffraction-limited telescopes intended for space-based observations. emphasizing foundational concepts like fermat's principle, schroeder applies these to optical systems crafted for imaging distant celestial bodies. wilson in his two-volume series [5,6] provides an in-depth exploration of the design, manufacture, and testing of reflecting telescopes. the first volume offers an overview of the optical theory and historical evolution of reflecting telescope systems. it covers fundamental design principles, including gaussian optics and aberration theory, and discusses field correctors and focal reducers. the book also provides a historical perspective, detailing major telescopes from lord rosse's era up to the 1980s. building upon the first volume, volume ii delves into modern developments in reflecting telescope optics over the past two decades. it addresses advancements in manufacturing and testing procedures, alignment techniques, and the integration of active control systems in telescopes. topics such as atmospheric and adaptive optics, dss vol. 6, no. 1, 2025, pp.49-90 51 reflecting coatings, and ancillary equipment are also explored. hardy’s [35] book provides an introduction to adaptive optics (ao) technology, which is used to correct distortions caused by atmospheric turbulence in astronomical observations. it covers fundamental ao principles, wavefront sensing, deformable mirrors, and real-time control systems. the book is essential for researchers, engineers, and astronomers working on highresolution imaging. in report no. 90 [39], one can find the optical design details of the 10-meter telescope used in keck observatory, among other things discussed. walker’s [7] book is a comprehensive guide that bridges the fields of optical engineering and human vision; it shows the intricate relationship between optical instruments and the human eye, providing both theoretical insights and practical design considerations. throughout the book, walker combines clear explanations with practical examples, making complex concepts accessible to both students and practicing engineers. geary [8] wrote a useful book (based on an introductory lens design course from the optical science & engineering doctoral program at the university of alabama in huntsville) dealing with lens design, rich with practical work (ansys zemax). the book offers a large number of illustrations, numerous examples, and problem solutions, making it suitable for both self-study and as a comprehensive introductory text. smith’s [9] book is a comprehensive guide that delves into the methodologies and applications of designing optical systems using computer-aided tools. throughout the book, smith adopts a practical and intuitive approach, minimizing complex mathematics to make the content accessible. the inclusion of numerous illustrations and problem solutions enhances comprehension, making it suitable for self-study or as a course textbook. o'shea and bentley [10] wrote an excellent book that demonstrates the process of designing optical systems using ansys zemax, a leading optical design software. published in 2024, this book offers a step-by-step approach to different lens designs, from initial definition through performance analysis and tolerancing. korsch’s [70] "reflective optics" is a foundational book focusing on the theory, design, and practical applications of reflective optical systems, especially those used in astronomical telescopes, space optics, and high-resolution imaging systems. unlike refractive optics, reflective systems rely entirely on mirrors, which are important in situations where chromatic aberration must be avoided or where wide wavelength ranges are used. oswalt made [71] is a comprehensive book that offers an in-depth exploration of the instruments and techniques that have revolutionized our understanding of the universe, and encompasses a wide range of topics, from traditional optical telescopes to cutting-edge spacebased observatories, providing readers with a holistic view of contemporary astronomical instrumentation. among several books in the field of amateur telescope-making, a few dozen stand out. suiter’s [11] book is a comprehensive guide that delves into the star test method, a powerful technique for assessing and diagnosing the optical performance of different telescopes directly under the night sky. this manual is particularly valuable for amateur astronomers and telescope enthusiasts seeking to evaluate and enhance their instruments without relying on complex equipment. allan mackintosh compiled [12,13] a two-volume series, based on selected articles from the maksutov circulars, a newsletter distributed over 21 years to members of the maksutov club. these volumes serve as guides for amateur and professional telescope makers, offering indepth insights into both the optical and mechanical aspects of telescope construction and enhancement. texereau [14] wrote a classic guide for amateur telescope makers. the book provides step-by-step instructions on grinding, polishing, and testing telescope mirrors, as well as constructing telescope mounts and other essential components. it covers optical theory, material selection, and practical techniques to help enthusiasts build high-quality reflecting telescopes. the book remains a fundamental resource for those interested in hands-on telescope fabrication. tonkin [15] edited a guide that compiles practical knowledge and techniques for constructing telescopes. it includes contributions from experienced telescope makers, covering topics such as grinding and polishing mirrors, assembling mounts, and optimizing optical performance. the book provides step-by-step instructions, technical insights, and hands-on guidance for hobbyists looking to build and refine their telescopes. it serves as an essential resource for amateur astronomers and diy telescope enthusiasts. clark [16] provided a practical guide for modern-day telescope makers, focusing on how to leverage the internet for sourcing materials, obtaining advice, and connecting with the global community of amateur astronomers. the book provides insights into using online resources to find parts, tools, and information for building telescopes, as well as how to troubleshoot and get expert help. it also includes tips on joining online forums, participating in virtual workshops, and using digital tools for design and testing. jim and dennis kriege [17] wrote a comprehensive guide to building and using dobsonian telescopes, which are known for their simplicity, stability, and excellent performance in amateur astronomy. the book covers everything from the basic principles of telescope design to step-by-step instructions on constructing a dobsonian mount and optimizing the optical system. it provides practical advice on materials, tools, and techniques, making it an invaluable resource for amateur astronomers interested in creating their own large, dss vol. 6, no. 1, 2025, pp.49-90 52 easy-to-use telescopes. ingalls [18,19,20] wrote three volumes, each offering practical guidance on designing, building, and testing telescopes, primarily aimed at amateur astronomers. volume 1 introduces the basics of telescope making, focusing on mirror grinding and polishing techniques. it also covers the construction of the telescope mount and the assembly of the optical system. volume 2 delves into more advanced techniques, including complex mirror designs, multi-element telescopes, and methods to improve optical performance. it emphasizes precision in crafting larger telescopes and finer optics, ideal for those with some experience in telescope making. volume 3 focuses on the construction of large telescopes, particularly those intended for serious amateur astronomical observation. it covers topics like large mirror making, sophisticated mounting systems, and fine-tuning optical performance for high-resolution astronomy. this volume is more technical and geared toward advanced hobbyists. remer [21] wrote a practical guide designed for amateur astronomers interested in constructing their own refractor telescopes. the book provides detailed instructions on how to craft high-quality optics, including lens making and alignment, as well as the construction of the tube and mounting system. it also covers the necessary tools and materials, giving step-by-step guidance on achieving a well-optimized refractor for both visual observation and astrophotography. highe [22] gave a practical guide aimed at amateur astronomers who wish to build or optimize portable newtonian telescopes. his book covers various aspects of telescope design, from choosing the materials and optics to constructing a stable, lightweight mount. it focuses on creating a telescope that is both easy to transport and capable of providing high-quality views for deep-sky observing. the book also includes tips for achieving optimal performance and providing advice on modifications to improve portability without compromising optical quality. daley’s [23] book provides a detailed exploration of the schupmann telescope design, an optical system that offers a combination of wide-field viewing and high-quality imaging. the book focuses on how this design works, its optical advantages, and the engineering involved in constructing such telescopes. daley covers the theoretical foundation behind the schupmann design, as well as practical guidance on building and fine-tuning these telescopes. this is useful for amateur astronomers looking to explore a unique and less common optical design. for information on amateur telescope optics, one should also visit the following websites: amateur telescope optics [40] by v. sacek (this site offers detailed insights into telescope design, optical theory, and practical advice for enthusiasts), telescope optics topics [41] by b. greer (a repository of personal research focusing on newtonian telescope design, including articles and companion pages for magazine features), astronomical optics [155], telescope optics for hobbyists [42] by edmund optics (provides guidance on building telescopes, understanding different types, and selecting appropriate components), as well as online forums, such as one at cloudy nights astronomical community [43]. 2.1. review of scientific papers the field of astronomical telescope design is supported by an extensive and growing body of scholarly work, comprising hundreds of high-quality research papers and technical articles. given the sheer volume of publications, it is challenging to isolate and highlight individual contributions without overlooking many others of significance. consequently, this review selectively presents a representative subset of the literature, focusing on papers that offer valuable insights into key design principles, innovations, and emerging trends in telescope technology. while this selection does not claim to be exhaustive due to the breadth and diversity of research in the field it aims to provide a meaningful overview of current research directions and foundational studies in this area. by drawing from a variety of sources, this review captures the multifaceted nature of telescope design, encompassing optical theory, material science, engineering challenges, and practical applications for both amateur and professional astronomy. the curated list serves not only to illustrate the state of the art but also to identify areas where ongoing research is actively pushing the boundaries of telescope performance and usability. pease's 1935 paper, "modern large telescope design" [24], published in the journal of the optical society of america, delves into the advancements and methodologies in constructing large-scale optical telescopes. pease, a pivotal figure at the mount wilson solar observatory, contributed significantly to the design of major instruments, including the 100-inch hooker telescope and the 200-inch hale telescope. his expertise in astronomical instrument design has been instrumental in shaping modern observational astronomy. feinberg dss vol. 6, no. 1, 2025, pp.49-90 53 et al. [25] published an overview of the multifaceted factors influencing the design of astronomical space telescopes. it introduces performance metrics that translate scientific goals into design requirements and discusses cost estimation factors such as mass, complexity, technology maturity, and heritage. the authors aimed to provide a roadmap for future space telescope designers to optimize designs that enhance scientific capabilities while minimizing total costs. endelman [26] provides an overview of the hubble space telescope (hst), from its inception through its early challenges, design, and subsequent remedies. launched in april 1990 after nearly fifteen years of development, the hst aimed to advance our understanding of the universe by observing celestial phenomena without atmospheric interference. however, initial images revealed a significant issue: the primary 2.4-meter mirror suffered from spherical aberration due to a manufacturing flaw, leading to blurred images. additional complications arose with the solar arrays, guidance systems, and auxiliary equipment. to address these issues, an 11-day servicing mission commenced on december 2, 1993, during which astronauts aboard the space shuttle endeavour replaced and repaired malfunctioning components. mcelwain et al. [27] discuss the design, development, and in-orbit performance of the optical telescope element (ote) of the james webb space telescope (jwst). key points covered in the paper are design and architecture, alignment and wavefront sensing, deployment and commissioning, as well as performance and scientific impact. regarding jwst, contreras and lightsey [28] also provided a review of the mission optical requirements and optical architecture. they described the telescope design, highlighted some of the features of the baseline telescope, and discussed the nominal performance. in addition, their paper provided an overview of the wavefront sensing and control process and described some of the special optical analysis considerations necessary in a system needing remote, on-orbit alignment. parshley et al. [29] presented a common optical design for a 6-meter aperture, crossed-dragone telescope adopted by both the ccat-prime and simons observatory projects. the design offers a high-throughput, relatively flat focal plane with a 7.8-degree field of view at 3 mm wavelengths, suitable for submillimeter and millimeter observations. huiru ji et al [30] proposed a method to design a high-throughput telescope using an off-axis three-mirror anastigmat configuration combined with a scanning mechanism. the resulting design achieves an f-number of 6, a 60° × 1.5° field of view, and a focal length of 876 mm, making it suitable for optical remote sensing applications. sirsi et al [31] discuss the design of oasis, a proposed space telescope featuring a 14-meter inflatable primary reflector. the telescope is intended for high spectral resolution observations in the terahertz frequency range, utilizing aberration correction optics and a scanning mechanism to achieve a 0.1-degree field of regard with diffraction-limited performance. graves et al [32] paper addresses the integrated design and manufacturing processes of next-generation large telescopes. it covers topics from optical design to enclosure requirements, emphasizing the need for novel approaches to meet the scientific goals of future observatories. muslimov et al [33] present the design of an all-reflective, bi-folded schmidt telescope aimed at surveying extended astronomical objects with extremely low surface brightness. the innovative design incorporates a curved detector to achieve high image quality over a large field of view, making it suitable for deep-sky surveys. zhang et al [34] studied the conceptual optical design of a 6.5-meter wide-field survey telescope. the design emphasizes excellent image quality across a broad field of view, aiming to facilitate large-scale astronomical surveys with high efficiency. ho jin et al. [35] presented the development of a compact reflecting telescope tailored for a 3u cubesat platform, aiming to capture high-quality earth imagery. the authors designed a ritchey-chrétien type telescope with off-axis segmented mirrors. at an operational altitude of 700 km, the system can image approximately a 4 km by 2.3 km area of earth's surface. this design demonstrates the feasibility of integrating high-resolution reflecting telescopes into cubesat missions, offering a resilient alternative to lens-based systems. dss vol. 6, no. 1, 2025, pp.49-90 54 catalan [36] introduces approximate formulas to quantify axial coma resulting from surface tilt and decentering, as well as spherical aberration due to axial displacement. these formulas distinguish between aberrations induced by preceding subsystems and those intrinsic to the misaligned surface. this differentiation offers a straightforward approach to designing telescopic systems less sensitive to specific misalignments. catalan applies this method to a two-mirror astronomical telescope with a corrector, demonstrating significant reductions in sensitivity to tilt and despace misalignments. the paper also discusses the limitations of these solutions and the challenges in simultaneously correcting multiple misalignment types. stepp and strom [37] provide an overview of the initial design and development efforts for the thirty meter telescope (tmt) project. the tmt aims to construct a 30-meter diameter optical-infrared telescope to enable groundbreaking astronomical observations. the authors discuss key aspects of the project, including the scientific objectives driving the telescope's design, the technical challenges associated with constructing such a large segmented mirror system, and the adaptive optics required to achieve diffraction-limited performance. they also outline the collaborative efforts among various institutions and the planned timeline for the project's development phases. k. w. hodapp and colleagues [38] presented the development of the panoramic survey telescope and rapid response system (pan-starrs), initiated by the university of hawaii's institute for astronomy. the primary goal of pan-starrs was to detect potentially hazardous asteroids (phas) and conduct comprehensive sky surveys. the design emphasizes a wide field of view and rapid sky coverage, utilizing a large aperture and advanced optical components to achieve high image quality across a broad field. the paper details the optical design choices, including the configuration of mirrors and corrector elements, to meet the scientific objectives of asteroid detection and sky surveying. macias et al. [65] present a student-led initiative to design, fabricate, and evaluate a low-cost newtonian telescope using 3d printing technology. the primary objectives were to assess the feasibility of constructing functional telescopes with additive manufacturing and to develop educational resources that facilitate handson learning in astronomy and engineering. abdulrahman et al. [66] investigated how the positioning of the secondary mirror affects the optical performance of maksutov–cassegrain telescopes. utilizing zemax optical design software, the study models and analyzes two configurations (a and b). design a features a secondary mirror affixed directly to the inner surface of the maksutov corrector lens. design b employs a separate secondary mirror positioned between the corrector lens and the primary mirror, not attached to the lens. the study concludes that the configuration where the secondary mirror is not attached to the maksutov corrector lens (design b) offers superior optical efficiency and image quality. this design choice reduces aberrations and enhances overall performance, making it a preferable option for applications requiring high-precision imaging. hasan [67] presents a comprehensive analysis of the optical performance of a schmidt-cassegrain telescope (sct) design, with a particular focus on the effects of spider obscuration. utilizing zemax optical design software, the study aims to assess how the structural components, specifically the spider vanes supporting the secondary mirror, influence image quality. aljizany [68] explores the enhancement of the hubble space telescope's optical performance through the integration of nano-sensor technology at the eyepiece. utilizing the zemax optical design software, the study simulates the telescope's optical system to assess the impact of nano-sensors on image quality. alcant [69] presents a study on the design and simulation of a terrestrial refractive binocular telescope with adjustable effective focal length. it was investigated how changes in the effective focal length impact image quality and overall optical performance. other relevant papers, regarding the design of the astronomical telescope, with emphasis on amateur design, can be found in references [70-153]. dss vol. 6, no. 1, 2025, pp.49-90 55 3. image quality considerations the performance of an optical system is primarily influenced by the aberrations inherent in its design. these aberrations are categorized into two main types: 1. monochromatic aberrations: these occur when light of a single wavelength passes through the system. they are present in both refracting and reflecting optical systems. 2. chromatic aberrations: these arise due to the dispersion of light, where different wavelengths are refracted by varying amounts, leading to focus discrepancies. chromatic aberrations are exclusive to systems containing refractive elements. when aberrations are present in the image, the image of a point source becomes a blur, known as the "scattering figure" or "blur circle." this blur results from a combination of various aberrations rather than a single type. the primary monochromatic aberrations include:  spherical aberration: occurs when light rays parallel to the optical axis enter the system at different heights and converge at different points along the axis. this can be mitigated by restricting the aperture, though it may reduce light-gathering capacity.  coma: manifested as a comet-shaped blur, coma arises when off-axis light rays do not converge at the same point, leading to asymmetric image blurring. it is particularly problematic in astrophotography, as it distorts star images, making precise measurements challenging.  astigmatism: this aberration occurs when light rays in different planes (tangential and sagittal) focus at different points, resulting in an image that is sharp in one direction but blurred in another.  field curvature: refers to the phenomenon where the image is sharp only on a curved focal plane, not on a flat one. using a flat sensor or photographic plate leads to unsharp images at the periphery. this can be corrected by employing field flatteners or using curved photographic films.  distortion: unlike other aberrations, distortion affects the image scale rather than sharpness. positive distortion (pincushion) causes straight lines to bend inward, while negative distortion (barrel) causes them to bulge outward. 3.1 image quality criteria image quality criteria for telescopes refer to the set of factors and parameters that determine how well a telescope can produce clear, sharp, and accurate images of celestial objects. here are the key criteria commonly used to evaluate telescope image quality: 1. resolution o the ability to distinguish fine detail and separate closely spaced objects. limited by the telescope’s aperture and affected by diffraction. 2. contrast o the ability to display differences in brightness between features. high contrast is important for observing faint objects near bright ones. 3. aberration control o minimizing optical defects such as chromatic aberration, spherical aberration, coma, astigmatism, and field curvature. 4. field of view (fov) o the angular size of the sky visible through the telescope; wider fovs are better for extended objects or star fields. 5. light gathering power o the amount of light collected, primarily determined by aperture size, impacts brightness and detail visibility. 6. diffraction limit o the fundamental limit on resolution caused by light diffraction defines the best possible image sharpness. 7. image brightness o related to aperture and focal ratio, affecting the visibility of faint details. dss vol. 6, no. 1, 2025, pp.49-90 56 8. point spread function (psf) and airy disk size o describes how a point source (like a star) is imaged; a smaller and more concentrated psf means sharper images. 9. mechanical and thermal stability o stability affects focus consistency and image sharpness, as vibrations or temperature changes can degrade image quality. 10. optical coatings and transmission o quality anti-reflective coatings improve light throughput and reduce ghosting or flare. the three main types of astronomical telescopes mentioned here refractors, reflectors, and catadioptric systems (fig. 1) each have distinct optical designs that influence their image quality based on the criteria outlined above. fig. 1 scheme of refracting, reflecting and catadioptric telescope design [154] dss vol. 6, no. 1, 2025, pp.49-90 57 refractors use lenses to gather and focus light, offering high contrast and excellent mechanical stability due to their sealed tube design. they generally produce sharp, high-resolution images with minimal maintenance. however, they are prone to chromatic aberration, where different wavelengths focus at slightly different points, resulting in color fringing unless corrected by achromatic or apochromatic lens combinations. refractors often have a relatively narrow field of view and can be expensive at larger apertures due to the complexity and cost of high-quality lens glass and coatings. reflectors use mirrors, eliminating chromatic aberration since reflection is wavelength-independent. this allows for larger apertures at lower costs, resulting in superior resolution and light-gathering power, key advantages for deep-sky observation and astrophotography. however, reflectors can suffer from spherical aberration if mirrors are not precisely shaped and aligned. they may also exhibit coma and require regular collimation to maintain optical alignment. reflectors typically have open tubes, which can lead to thermal currents affecting image stability. catadioptric telescope designs combine lenses and mirrors to capitalize on the benefits of both systems while minimizing their weaknesses. these hybrid telescopes offer compact form factors and improved correction of aberrations, including reduced coma and spherical aberration. their optical coatings and design often provide good contrast and wide fields of view, making them versatile for both planetary and deep-sky imaging. however, their complex optical path can often lead to some light loss and require more precise manufacturing and alignment. generally, catadioptrics often have moderate focal ratios, balancing image brightness and field of view. telescopes have three main roles [155]:  light gathering & compression: they collect much more light than the eye, making faint objects visible. this gathered light is then focused into a smaller beam that can enter the eye or fit onto a sensor.  angular resolution & magnification: telescopes resolve fine details by having a much wider "pupil" than the eye. they then magnify this detailed image so the eye can see it, while the increased light grasp keeps the image bright enough.  pointing & tracking: telescopes can be aimed at any point in the sky and can follow celestial objects as the earth rotates, often using motorized mounts with computer control. important optical characteristics of telescopes are [155]: 1. aperture: determines light-gathering ability (fainter objects visible), image resolution (finer detail), the impact of atmospheric turbulence ("aperture seeing"), and partly the telescope's weight and size. 2. focal length: primarily dictates the telescope's magnification. longer focal lengths yield higher base magnification. in visual use, it sets the magnification range achievable with different eyepieces. it also influences the telescope's physical length. 3. focal ratio (relative aperture): affects image brightness; faster (lower number) ratios concentrate more light per area. it also determines the image scale for astrophotography. 3.2 spot diagrams spot diagrams are one of the fundamental analytical tools used in optical design. they are used to simulate and visualize the distribution of light from a point source as it appears on the telescope’s focal plane. by plotting the positions where rays of light converge, spot diagrams effectively illustrate the size, shape, and intensity pattern of the resulting image. these diagrams can provide a clear graphical representation of the impact of various optical aberrations, such as spherical aberration, coma, and astigmatism, on image quality. by examining spot diagrams, optical designers can assess the degree to which aberrations distort the ideal point image, evaluate the effectiveness of corrective measures, and optimize lens or mirror configurations to achieve sharper, more accurate images. in this way, spot diagrams serve as a critical diagnostic tool in the iterative process of refining telescope optics to meet desired performance standards. for visual observation, especially at high magnifications, the spread of spots in the focal plane should be minimal. typically, 90 to 95% of the rays should be concentrated within a circle no larger than the airy disk. an airy disk is the central bright spot in the diffraction pattern formed when light passes through a circular aperture, like a telescope lens. it represents the smallest point to which a perfect optical system can focus dss vol. 6, no. 1, 2025, pp.49-90 58 light, setting the limit of resolution due to diffraction. the airy disk's diameter depends on the focal ratio of the objective and the wavelength of light. for astrophotography, the image quality is traditionally determined by the resolving power of the photographic emulsion. research indicates that the smallest star images on professional astrophotographic plates have diameters no smaller than 0.025 mm [3]. 4. refracting (dioptric) telescopes refractor telescopes (fig. 1), among the earliest optical instruments designed for astronomical observation, utilize lenses to gather and focus light, producing magnified images of distant objects. invented in the early 17th century, these telescopes have evolved significantly, finding applications in astronomy, terrestrial observation, and optical research. the fundamental principle of a refractor telescope involves the refraction of light through a convex objective lens to form a real image, which is then magnified by an eyepiece. the history of refractor telescopes begins with hans lippershey, who patented the first refracting telescope in 1608, though galileo galilei popularized its use in astronomy shortly thereafter with his improved designs [44]. early refractors suffered from chromatic aberration, a distortion caused by the varying refraction of different wavelengths of light, resulting in colored fringes around observed objects [45]. sir isaac newton’s work on optics in the late 17th century highlighted these limitations, prompting the development of achromatic lenses by chester moore hall and john dolland in the 18th century [46]. these lenses, combining crown and flint glass, significantly reduced chromatic aberration, enhancing image clarity [47]. in the 19th century, advancements in glass manufacturing and lens grinding, as documented by joseph fraunhofer, allowed for larger objective lenses with improved light-gathering capabilities [48]. fraunhofer’s work on apochromatic lenses, which correct for three wavelengths of light, further refined refractor performance. modern literature, such as born and wolf’s principles of optics, provides a detailed theoretical framework for understanding lens aberrations and their correction in refractor designs [49]. recent studies explore the integration of adaptive optics and digital imaging in refractors, expanding their utility beyond traditional astronomy. the design of a refractor telescope involves several key components: the objective lens, the tube assembly, the focuser, and the eyepiece. each element requires precise engineering to optimize performance. 4.1 objective lens design the objective lens is the heart of a refractor telescope, determining its light-gathering power and resolution. the lens’s focal length (f) and aperture (d) dictate the telescope’s magnification and field of view, calculated as m=fobjective/feyepiece. to minimize chromatic aberration, modern refractors employ achromatic or apochromatic lens systems. an achromatic doublet (fig. 2) typically pairs a convex crown glass lens (low dispersion) with a concave flint glass lens (high dispersion), aligning red and blue wavelengths at a common focal point [50]. early achromatic refractors, developed around 1760 by john dollond and jesse ramsden, featured small doublet lenses (aperture ~130 mm). advances in flint glass production by pierre louis guinand enabled joseph von fraunhofer to design a larger 240 mm air-spaced doublet (fig. 2), first used in the dorpat refractor. this fraunhofer doublet, with a crown and flint lens separated by a small air gap, offered four optical surfaces to correct chromatic and spherical aberration, as well as coma. optimal performance is usually achieved at focal ratios between ƒ/10 and ƒ/20, with faster ratios used for wide-field applications like astrophotography. the steinheil achromatic doublet (fig. 2) positions the flint glass element at the front and the crown glass at the rear, unlike the more common fraunhofer design. this configuration requires stronger lens curvatures and typically features a narrower air gap between the elements. while it offers improved correction of optical dss vol. 6, no. 1, 2025, pp.49-90 59 aberrations, its use is limited due to the flint glass's susceptibility to atmospheric moisture, which can lead to degradation such as spotting or opacity over time [155]. fig. 2 scheme of refracting achromatic designs (fraunhofer and steinheil) [155] in table 1 are given several other achromat doublet designs as well, presented in [40]. these specifications are for 100 mm aperture, ƒ/10 lenses. however, they can be adapted for refractors with similar apertures, ranging from about 50% faster to slower focal ratios. this scaling is done by directly applying the desired focal ratio to the given radii, requiring only small ray tracing tweaks. similarly, swapping out comparable glass types should only need minor adjustments. glass thickness isn't a concern, except in the case of gausstype. table 1. achromat doublets designs, general specifications for bk7/f2 glass (in units of focal length) [40] type aplanat r1 t1 m1 r2 air (m2) r3 t3 m3 r4 fraunhofer yes 0.6 0.011 bk7 -0.36 0.001 -0.363 0.007 f2 -1.51 steinheil yes 0.442 0.007 f2 0.229 0.001 0.2285 0.009 bk7 -15 baker yes 0.582 0.011 bk7 -0.363 0.003 -0.363 0.007 f2 -1.59 littrow no 0.45 0.01 bk7 -0.45 0.00005 -0.45 0.006 f2 -7.7 clark no 0.428 0.01 bk7 -0.428 0.015 -0.4 0.0065 f2 -8 gauss (f/14 and slower) yes 0.129 0.00665 bk7 0.3345 0.0003 0.14206 0.0042 f2 0.10357 cooke no 0.373 0.009 bk7 -0.563 0.001 -0.527 0.006 f2 4.7 apochromatic lenses (fig. 3), often triplets, incorporate an additional element (e.g., extra-low dispersion glass) to align three wavelengths, reducing residual color aberration [51]. invented in 1840 by hungarian optician joseph petzval, this apochromatic lens (f/4 – f/6) design uses two separated doublets (one cemented, one not). initially a fast portrait lens (around ƒ/4) for early photography, its doublets can be refined for telescopes to minimize color distortion across a wider field (about 5°). petzval lenses produce a sharp center but have curved and distorted edges. the lens's aperture creates a characteristic blurred background (bokeh) seen in 19th-century portraits. astronomer e.e. barnard used a petzval for milky way photos, leading to versions specifically made for astronomy, like tele vue's design. by the late 1800s, more diverse optical glasses enabled ernst abbe and peter rudolph at zeiss to create apochromatic microscope lenses in 1890. however, h. dennis taylor at cooke & sons patented the first large triplet lens with apochromatic qualities in 1892. this "cooke triplet" design (f/4 – f/6), using a crown lens doublet paired with a negative flint to balance dispersion, is the foundation for modern apochromatic lenses. today's apochromatic refractors are usually triplet lenses (air, oil, or cemented) initially made with synthetic fluorite for the crown element and two high-dispersion flint glasses. the specific glass types significantly impact both optical quality and lens lifespan. air-spaced designs include screws for precise alignment (centering and collimation). the first modern commercial apochromats were takahashi's ts series, using synthetic fluorite. in 1981, astro-physics (roland christen) introduced an oil-spaced triplet using a flint glass initially developed for nasa. a common structure involves a front double convex crown, a middle negative flint, and a rear double convex flint [155]. dss vol. 6, no. 1, 2025, pp.49-90 60 fig. 3 scheme of refracting apochromatic designs (petzval, cooke, takahashi) [155] 4.2 tube assembly the telescope tube aligns the optical components and shields them from stray light. its length approximates the focal length of the objective lens, though baffles and coatings are added to reduce internal reflections [52]. materials like aluminum or carbon fiber are chosen for their rigidity and low thermal expansion, ensuring optical stability across temperature variations. 4.3 focuser and eyepiece the focuser adjusts the eyepiece position to achieve sharp focus, typically using a rack-and-pinion or crayford mechanism for precision. the eyepiece, a secondary lens system, magnifies the image formed by the objective. common designs include huygens, kellner, and plössl eyepieces, each offering trade-offs in field of view and eye relief. the choice of eyepiece depends on the intended application, with wider fields preferred for deep-sky observation [53]. eyepieces are usually sold separately and on the market variety exists. dss vol. 6, no. 1, 2025, pp.49-90 61 4.4 testing and optimization optical testing, such as the ronchi or foucault test, evaluates lens quality by analysing interference patterns or knife-edge shadows [54]. computer-aided design (cad) software, like zemax, simulates light paths to optimize lens spacing and coatings, enhancing transmission and contrast [55]. 4.5 applications refractor telescopes serve diverse purposes in both professional and amateur contexts. in astronomy, their high contrast and sharp imaging make them ideal for observing planets, double stars, and lunar details. the apochromatic refractors used in observatories, such as the 1-meter refractor at yerkes observatory, exemplify their precision for stellar spectroscopy and astrophotography. beyond astronomy, refractors are employed in terrestrial observation, such as wildlife monitoring, due to their portability and upright image orientation (with a diagonal prism). in education, small refractors introduce students to optics and celestial navigation, while in research, they contribute to studies of atmospheric optics and light pollution. their versatility is enhanced by modern adaptations, including digital sensors for real-time imaging. refractor telescopes remain a cornerstone of optical technology, blending historical significance with modern innovation. their design, rooted in the precise manipulation of light through lenses, has evolved from simple galilean instruments to sophisticated apochromatic systems capable of high-resolution imaging. the methods of design combining advanced lens crafting, robust mechanical engineering, and optical testing ensure their continued relevance. while reflecting telescopes dominate large-scale astronomy due to their scalability, refractors excel in clarity and contrast for smaller apertures. future advancements may integrate adaptive optics and ai-driven image processing, further expanding their capabilities. 4.6 technical considerations refractors suffer from residual chromatic and spherical aberration. this affects shorter focal ratios more than longer ones. an f/6 achromatic refractor is likely to show considerable color fringing (a purple halo around bright objects); an f/16 achromat has much less color fringing. in very large apertures, there is also a problem of lens sagging, a result of gravity deforming glass. since a lens can only be held in place by its edge, the center of a large lens sags due to gravity, distorting the images it produces. the largest practical lens size in a refracting telescope is around 1 meter. there is a further problem of glass defects, striae or small air bubbles trapped within the glass. in addition, glass is opaque to certain wavelengths, and even visible light is dimmed by reflection and absorption when it crosses the air-glass interfaces and passes through the glass itself. most of these problems are avoided or diminished in reflecting telescopes, which can be made in far larger apertures and which have all but replaced refractors for astronomical research. examples of the largest achromatic refracting telescopes are: great paris exhibition telescope of 1900 (1.25 m) dismantled after exhibition, yerkes observatory (101.6 cm), swedish 1-m solar telescope (98 cm), lick observatory (91 cm), paris observatory meudon great refractor (83 cm), potsdam great refractor (80 cm), nice observatory (77 cm), john wall (76.20 cm) dialyte refracting telescope the largest refractor built by an individual, at hanwell community observatory, 28-inch grubb refractor at royal greenwich observatory, (71 cm), great refractor of vienna observatory, (69 cm), archenhold observatory – the longest refracting telescope ever built (68 cm × 21 m), united states naval observatory refractor (66 cm), newall refractor at the national observatory of athens (62.5 cm), lowell observatory (61 cm). 4.7 image quality in refracting telescopes a single lens has multiple optical aberrations, so refractor objectives use multiple elements to reduce them, especially longitudinal chromatic and spherical aberration. coma should also be minimized across a wide field. chromatic aberration occurs because different wavelengths of light refract differently. blue light focuses closer to the lens than green or red. in negative lenses, focal points are virtual and in front of the lens. dss vol. 6, no. 1, 2025, pp.49-90 62 achromatic correction uses two closely spaced lenses: a positive crown glass lens (n ≈ 1.5, low dispersion) and a negative flint glass lens (n ≈ 1.6, high dispersion). the positive lens has lower power and dispersion than the negative one. bending both lenses reduces spherical aberration and coma. air-spacing them allows more design flexibility. however, astigmatism and field curvature cannot be corrected in standard achromatic doublets, making them unsuitable for wide-angle, sharp imaging on flat film. generally, designers can adjust 10 variables glass types, curvature radii, airspace, element order, and thicknesses to reduce aberrations. the difference between red/blue and green focus is called the secondary spectrum (fig. 4). fraunhofer-type doublets reduce it to 1/2000 of the focal length, semiapochromats to 1/4000, and with advanced glass to 1/8000. the best correction uses fluorite (n = 1.43, v = 95.6), reducing the secondary spectrum to 1/16000 but it's very expensive and delicate (prone to weathering). in conventional doublets, the secondary spectrum is acceptable when the red and blue blurs do not exceed three times the diameter of the airy disk (in green light). so, the condition for freedom from chromatic aberration is: fmin=0.122d, where fmin is the minimum focal ratio, and d is the aperture diameter. for example, for an aperture of 100 mm, the fastest focal ratio giving full achromatism is f/12.2. in doublets corrected for green light, red light is undercorrected and blue is overcorrected, a wavelength-dependent distortion called spherochromatism. this effect occurs in all cemented and narrow-air-gap doublets but can be managed with wider spacing [3]. fig. 4 color curve for a visually corrected doublet (left); secondary spectrum in a doublet lens (right) [3] in [3], a comparison between three 200 mm doublet objectives for refractors, fraunhofer f/15, cemented apoklaas f/8, and fluorite (steinheil) f/8 types is presented. fraunhofer design uses standard glass and has the largest color error. apoklaas uses special glass to halve the secondary spectrum, while the fluorite lens reduces it further, but is sensitive to weathering, so it's placed behind the negative element (steinheil design). fluorite lenses allow for faster, shorter telescopes. design parameters of these refractors are given in table 2. table 2. design characteristics of three different double refractor designs [3] parameter fraunhofer f/15 apoklaas f/10 fluorite ƒ/8 r, radius of curvature 2009.753 1175.900 546.292 t, axial dis. 31.336 24 12 m, medium 517642 487845 720504 r₂ -976.245 -513.920 356.146 t₂ 3.315 1 1 m₂ air air air r3 -985.291 -522.606 348.299 ꭲ, 25.109 12 24 m3 613370 558542 fluorite r₁ -3636.839 -2756.828 -6670.445 t₁ back focal length 2968.12 2000 1599.996 m₁ air air air efl 3000 2020 1600 1° field 52.4 35.3 27.9 note that optical glasses have international standardized six digit code (see table 2 for medium designations). this indicates the first three digits after the decimal point in the refractive index, nd, and the first three digits dss vol. 6, no. 1, 2025, pp.49-90 63 of the abbe number, vd. this means that a glass 517642 has a refractive index of 1.517 and an abbe number of 64.2 (the catalogues show that this glass is bk7, a borosilicate crown glass made by schott inc). the spot diagrams in fig. 5 show that the fraunhofer lens has significant color aberration (red/blue spots ~5× the airy disk). apoklaas and fluorite lenses show much better correction (~1.5× the airy disk). however, the fluorite lens, though best for color correction, suffers more from spherochromatism. despite good visual correction, all these objectives show poor violet correction, especially in photography. fig. 5 spot diagrams for three 200 mm refractor objectives, as reported in [3] dss vol. 6, no. 1, 2025, pp.49-90 64 regarding previous doublet designs (table 2 and fig 5), it can be said that air-spaced lenses allow optimal single-color aberration correction with any glass. cemented doublets need specific glass pairs with matching curves for best correction (though a small air gap works similarly). a problem with larger (around 100mm+) cemented doublets is that temperature changes can harm the lens bond [40]. to focus red, blue, and violet light together, designers use apochromatic objectives with three lenses made from different materials. these reduce secondary spectrum to about 1/10,000 of the focal length, making them better than achromats for photography [3]. apochromatic triplets use two crown lenses designed to have a combined dispersion similar to a particular flint glass. while ernst abbe defined a true apochromat as a lens with parfocal correction for three distant colors and spherical aberration and coma correction for two, modern "apochromatic" lenses don't fully meet this strict definition. correcting focus variations across wavelengths (spherochromatism) perfectly requires very long focal lengths, large air gaps, aspherical surfaces, or a petzval design. instead, modern lenses minimize spherochromatism using some of these methods, and coma is corrected for one wavelength, which largely reduces it across the visible spectrum. for wider photographic views and easier portability with shorter tubes, most modern refractors have smaller focal ratios, typically ƒ/8 to ƒ/5. special optical glass, known as ed or extra-low dispersion glass, enables more precise lens designs that better minimize both coma and chromatic aberration. achromatic lenses incorporating ed glass are sometimes sold as ed achromats or semi-apochromats, like those from skywatcher. to control increased optical distortions at higher magnifications, a third lens is incorporated into apochromatic designs, often marketed as apo or apo triplets by companies such as tec, astro-physics, takahashi, and sky-watcher. an even more advanced design uses a fourth lens to create a crown element combined with an ed triplet, referred to as a super apochromat, as nowadays seen in takahashi's tsa refractors [155]. 5. reflecting (catoptric) telescopes reflector telescopes (fig. 1), which employ mirrors to collect and focus light, represent a pivotal advancement in optical astronomy. unlike refractors, which use lenses, reflectors avoid chromatic aberration, making them ideal for observing faint, distant celestial objects. the inception of reflector telescopes is credited to sir isaac newton, who constructed the first functional model in 1668 using a concave primary mirror and a flat secondary mirror to redirect light to an eyepiece. newton’s design addressed the chromatic aberration inherent in refracting telescopes, a problem he identified in his optical studies [45]. in the 18th century, james gregory proposed an alternative configuration with a parabolic primary mirror and an elliptical secondary mirror, though practical implementation lagged due to manufacturing challenges [56]. william herschel’s large reflectors in the late 18th century demonstrated the potential of mirrors for deep-sky observation, despite difficulties with speculum metal (a mixture of around two-thirds copper and one-third tin), an alloy prone to tarnishing. the 19th century saw significant progress with the introduction of silvered glass mirrors by léon foucault and the development of parabolic grinding techniques. john hadley’s work on mirror figuring further refined optical precision, enabling sharper images. in the 20th century, the advent of aluminized coatings, as described by strong, improved mirror reflectivity and durability [57]. modern literature provides a rigorous analysis of aberration correction and mirror alignment in advanced designs like the ritchey-chrétien telescope [5,6]. recent studies explore the integration of segmented mirrors and adaptive optics, pushing the boundaries of reflector capabilities. the design of a reflector telescope hinges on its optical system, structural support, and alignment mechanisms. key components include the primary mirror, secondary mirror, tube assembly, and mount. main types of reflecting telescopes include: newtonian, gregorian, classical cassegrain, ritchey chrétien, dall kirkham, as presented in fig. 6. parameters in fig. 6 are: f – effective focal length, f1 – primary focal length, and fbfl – back focal length. dss vol. 6, no. 1, 2025, pp.49-90 65 fig. 6 main types of reflecting telescopes [155] dss vol. 6, no. 1, 2025, pp.49-90 66 the newtonian reflector (f/4 f/12), easy to make and with good light grasp, was popular among amateurs for most of the 20th century. its unfolded light path results in long tubes, typically with focal ratios no faster than ƒ/10, though faster ratios are used for light gathering. astigmatism is eliminated when the focal point is as far from the mirror as the tube opening. long focal ratio or large aperture newtonians often require a ladder to reach the eyepiece; the dobsonian mount with a short focal ratio (ƒ/5 or less) can lessen this. at fast focal ratios, coma becomes noticeable but can be lessened with a coma corrector lens. the primary is a paraboloid, and the secondary is flat (plane). the gregorian telescope (f/4 – f/40), theorized by mersenne in 1636 and gregory later, was first built by hadley in 1726. it produces an upright image by reflecting light off two mirrors, inverting it twice. this design typically requires a longer tube than a cassegrain, which is often seen as a disadvantage. its high magnification makes it well-suited for observing the moon, planets, and double stars. however, it has a narrow usable field of view and noticeable off-axis distortions. the primary is an ellipsoid, and the secondary paraboloid. the cassegrain telescope (f/4 f/12), proposed by mersenne and later cassegrain, offers a long focal length in a compact tube. while its usable field is narrow and off-axis distortions are present, its high magnification excels for observing the moon, planets, and double stars, and allows for more comfortable eyepieces. the short tube provides better balance and stability. the primary is a paraboloid and the secondary hyperboloid. the ritchey-chrétien (rc) design (f/8 f/10), based on schwarzschild's ideas, eliminated spherical aberration and coma found in earlier reflectors. modern rcs often have higher secondary magnification (smaller obstruction) and surfaces closer to a paraboloid. rcs produce perfectly round star images, ideal for astrophotography, and are common in very large telescopes. however, they exhibit significant astigmatism beyond a 0.7° field and have the most pronounced field curvature of any design, causing stars at the image edges to appear larger. both primary and secondary are hyperboloids. the dall-kirkham design (f/12 – f/20) uses easily manufactured and tested mirrors, lowering costs and easing collimation compared to cassegrain or rc telescopes. however, it suffers from significant coma (2-6 times more than a classic cassegrain) and a narrow field, making it poor for wide-field photography. image quality worsens with higher secondary magnification. the primary is a prolate ellipsoid, and the secondary is spherical. the pressman-camichel design, with reversed mirror shapes, has even more coma, 4-12 times that of a classic cassegrain [155]. 5.1 primary mirror design the primary mirror collects and focuses incoming light, with its aperture (d) determining light-gathering power and its focal length (f) setting the image scale. most modern reflectors use a parabolic mirror (or other shapes, see fig. 6) to eliminate spherical aberration, ensuring a sharp focus for on-axis rays [50]. materials like pyrex or zerodur are favored for their low thermal expansion, minimizing distortion from temperature changes. the mirror is coated with aluminum or silver via vacuum deposition to achieve high reflectivity (typically >90%) across visible wavelengths. 5.2 secondary mirror and optical configuration the secondary mirror in reflectors redirects light to the eyepiece or detector. in the newtonian design, a flat diagonal mirror reflects light to the side of the tube [52]. the cassegrain configuration uses a convex hyperbolic secondary to fold the light path back through a hole in the primary, extending the effective focal length within a compact tube. the ritchey-chrétien variant employs two hyperbolic mirrors to correct coma, enhancing off-axis image quality for wide-field observations [3]. these can be seen in fig. 6. generally, the secondary’s size and tilt are optimized to minimize obstruction while maintaining alignment with the primary mirror [5,6]. 5.3 tube assembly and mount the tube supports the mirrors and shields them from stray light. open truss designs, common in large reflectors, reduce weight and thermal gradients, while solid tubes suffice for smaller instruments. the mount, dss vol. 6, no. 1, 2025, pp.49-90 67 typically equatorial or alt-azimuth, ensures precise tracking of celestial objects. computer-controlled altazimuth mounts with derotators are standard in modern observatories, compensating for field rotation. 5.4 testing and alignment mirror figuring is tested using interferometry or the foucault test to verify surface accuracy to within a fraction of a wavelength. collimation, the alignment of optical elements, is critical and often achieved with laser or star tests [54]. for segmented mirrors, as in the keck telescope, active control systems adjust individual segments in real time. 5.5 applications reflector telescopes dominate professional astronomy due to their scalability and versatility. large reflectors, such as the 10-meter keck telescopes, enable observations of distant galaxies, quasars, and exoplanets, leveraging their superior light-gathering capacity. the hubble space telescope, a ritchey-chrétien type reflector, has revolutionized cosmology with its deep-space imaging. in amateur astronomy, newtonian reflectors are popular for their cost-effectiveness and performance in observing nebulae and star clusters [53]. beyond astronomy, reflectors are used in optical testing, laser communication, and solar concentrators, where large apertures and precise focusing are advantageous [58]. their adaptability is enhanced by innovations like adaptive optics, which correct atmospheric distortion for ground-based observatories [59]. reflector telescopes exemplify the synergy of optical theory and engineering precision, offering unmatched capabilities for astronomical observation. from newton’s initial design to modern segmented and adaptive systems, their evolution reflects advances in materials, manufacturing, and computational techniques. the design process, centered on crafting parabolic mirrors, optimizing optical layouts, and ensuring structural stability, underpins their success across diverse applications. while smaller refractors excel in planetary imaging, reflectors dominate large-scale research due to their freedom from chromatic aberration and ability to scale to massive apertures. future developments may focus on lightweight mirrors and ai-driven alignment, further enhancing their potential. 5.6 image quality in newtonian reflecting telescope the newtonian telescope is among the simplest and most widely used reflecting designs, particularly favored by amateur astronomers. it is also the most frequently constructed telescope by hobbyists, effectively making it the benchmark for evaluating other telescope types. this telescope design includes a paraboloidal (commonly misnamed as "parabolic") primary mirror and a flat secondary mirror, which redirects the focused light out of the tube for either visual observation or photography. newtonians typically have focal ratios ranging from f/4 to f/12. focal ratios below f/4 are impractical due to significant coma near the edges of the field, while ratios above f/12 result in telescopes that are excessively long. telescopes with slower focal ratios (f/7 to f/12) are best for viewing the moon and planets, while faster focal ratios (f/4 to f/6) are more suitable for deep-sky observations and astrophotography at the prime focus. in smaller, slower newtonian telescopes, a spherical mirror may be used instead of a paraboloidal one. although most modern newtonians use paraboloidal mirrors, beginners often start with spherical mirrors due to their ease of manufacture and price. the diagonal mirror, which redirects the light path, causes a central obstruction in the primary mirror. while it must be large enough to cover the desired field of view, it should be kept as small as possible to minimize negative effects on image quality. for visual observation, a fully illuminated field of about 10 mm in diameter is sufficient. however, newtonians intended for photographic use require a larger diagonal to fully light the image area. ideally, a telescope designer aims to use the smallest possible secondary mirror, not only to minimize light loss but also to reduce image contrast degradation caused by diffraction. discerning observers dss vol. 6, no. 1, 2025, pp.49-90 68 can notice a decline in image quality when the central obstruction is 20% of the aperture, and it is generally agreed that it should not exceed 30%. a secondary mirror that is too small is not practical. in addition to the risk of surface imperfections near the edge of the diagonal mirror, such a small mirror may fail to fully capture and reflect the entire light cone. in fast newtonian telescopes, the secondary mirror needs to be positioned slightly closer to the primary mirror and farther from the focal point to ensure that the focal plane is evenly illuminated around the optical axis. as a general guideline, illumination at the corners of a photograph should not decrease by more than 30 to 40%. for visual observing, a fully illuminated field with a 10 mm diameter is typically adequate [3]. 5.6.1 newtonian telescope with spherical mirror in a spherical (concave) mirror, light rays that travel near the optical axis (paraxial rays) converge at a specific point-paraxial focus (designated as f in fig. 7). however, rays farther from the axis come to focus nearer to the mirror, resulting in spherical aberration. figure 7 illustrates a series of axial spot diagrams taken at different focal planes for a 200 mm spherical mirror with an f/8 focal ratio. the sequence begins at the paraxial focus (0.0 mm), and the light blur is smallest at a point 0.6 mm inside this focus. the way the blur size and the concentration of light in the image center change (shown in fig. 7) is a typical signature of spherical aberration. in slower newtonian telescopes, parabolizing the mirror isn’t always necessary if the spherical aberration blur remains smaller than the airy disk [3]. fig. 7 spot diagrams (at different focal planes) for a 200 mm f/8 spherical mirror [3] in fig. 8, the spot diagram sizes for various focal ratios with both the size of the corresponding airy disks and the 0.025 mm photographic resolution limit are compared. for a 200 mm newtonian telescope, a spherical mirror performs adequately for visual use at f/12 or slower (fig. 8). for photographic purposes, mirrors used at f/8 or slower also do not require parabolizing. fig. 8 smallest blur spot diagrams for 200 mm spherical mirrors [3] dss vol. 6, no. 1, 2025, pp.49-90 69 5.6.2 newtonian telescope with paraboloidal mirror near the optical axis, spherical and paraboloidal mirrors share an identical radius of curvature. however, as you move farther from the axis, the spherical surface must be shaped slightly backward to ensure all rays converge at the same focal point (f), thereby correcting spherical aberration. this modified shape is a paraboloid. for mirrors with focal ratios of f/8 or slower, the difference between the edges of a spherical and a paraboloidal mirror is less than the wavelength of green light. the primary optical defect in a newtonian telescope is coma. astigmatism also occurs, but typically only at wider image angles, and field curvature is another present but less significant aberration. when the entrance pupil is located at the mirror, which is usually the case, the optimal focal surface is positioned between the tangential and sagittal focal planes and curves inward with a radius equal to the telescope’s focal length. since coma greatly outweighs the other aberrations in newtonian designs, using a curved photographic film or a field flattener offers minimal improvement. figure 9 presents spot diagrams for focal ratios ranging from f/4 to f/12, measured at off-axis distances of 0, 10, 20, and 30 mm on an optimally curved focal surface. at larger off-axis distances, particularly with fast primary mirrors, significant coma and astigmatism become apparent. coma is the dominant aberration near the optical axis, while astigmatism appears farther out, identifiable by a secondary tail forming in the comatic blur pattern [3]. fig. 9 spot diagrams for 200 mm paraboloidal mirrors [3] dss vol. 6, no. 1, 2025, pp.49-90 70 assessing the newtonian telescope’s field that is usable for photography is challenging because photographic film or ccd/cmos sensors may not capture the faint outer parts of the comatic blur. as a result, actual photographic images appear smaller than spot diagrams suggest. however, since some light is lost from the image center, the limiting magnitude is reduced. when high-quality photographic results are required, the 0.025 mm spot size criterion should be used. for less demanding applications, a blur of up to 0.100 mm at the edge of the film frame generally produces images that are acceptable to most astrophotographers. cassegrain telescopes often suffer from sky flooding, where stray light reaches the focal surface without mirror reflection, reducing contrast. baffling is needed to block this stray light, but it increases central obstruction and may cause light loss at the field edges, especially in wide-field photography [3]. 5.7 image quality in the cassegrain-type reflecting telescope cassegrain telescopes use a concave primary mirror and a small secondary mirror placed before the primary’s focus. different designs vary by mirror shapes: classical (paraboloid primary, hyperboloid secondary), dallkirkham (prolate ellipsoid primary, spherical secondary), ritchey-chrétien (both hyperboloid), and pressmancamichel (spherical primary, oblate ellipsoid secondary). the secondary mirror reflects light toward the primary, forming an image behind it for easy observation or photography. the secondary also increases the system’s focal length but blocks some light, reducing brightness and contrast, so it’s kept as small as possible. ideal cassegrain designs feature a short tube, small secondary, flat focal surface, and accessible focal plane, but achieving all simultaneously is impossible. field curvature, caused by the secondary’s shape, is a key challenge and is more pronounced than in newtonian or refractor telescopes. the field curves inward (concave to the sky). a flat focal surface requires equal radii of curvature of both mirrors, which conflicts with having a short tube and a small secondary. high secondary magnification designs favor a short tube and small secondary but suffer from strong field curvature, which is fine for visual use but problematic for photography. field curvature worsens as the secondary gets smaller and the mirrors get closer. designers must balance between visual telescopes with small secondaries and strong curvature and photographic telescopes with larger secondaries and flatter fields. field curvature can be corrected with curved film or field flatteners and mostly affects amateur scopes; professionals use additional optics or curved plates to compensate [3]. a cassegrain telescope can be designed to eliminate spherical aberration, allowing for a sharp image at the optical axis, as long as the correct shapes are selected for both the primary and secondary mirrors. but the clarity of off-axis images is influenced by the shapes of these surfaces. the four key combinations of cassegrain telescopes are presented in table 3. note that schwarzschild constants (sc) are following: a sphere has an sc of 0 (indicating no deformation), prolate ellipsoid has an sc between -1 and 0, paraboloid has an sc equal to -1, hyperboloid has an sc less than -1, and an oblate ellipsoid has an sc greater than 0. table 3. characteristics of four 200 mm f/8 cassegrain telescopes (dimensions in mm) [3] classical ritchey-chrétien dall-kirkham pressmann-camichel focal ratio 8 8 8 8 effective focal length 1600 1600 1600 1600 secondary magnification 8/3 8/3 8/3 8/3 primary radius of curvature -1200 -1200 -1200 -1200 primary schwarzschild constant -1 -1.13682 -0.61328 0 secondary radius of curvature -628.36 -628.36 -628.36 -628.36 secondary schwarzschild constant -4.84 -6.55243 0 7.6755 mirrors separation -403.64 -403.64 -403.64 -403.64 back focal length 523.64 523.64 523.64 523.64 1° field 27.9 27.9 27.9 27.9 dss vol. 6, no. 1, 2025, pp.49-90 71 some opticians prefer the simpler spherical secondary of the dall-kirkham over the more complex hyperbolic secondary of the classical cassegrain. while easier to make, the dall-kirkham suffers from strong coma, limiting its field. the pressmann-camichel, with a spherical primary and heavily deformed secondary, also shows severe coma and supports only a narrow field. the ritchey-chrétien corrects coma and allows a wider field, but its highly aspheric mirrors are difficult to produce, making it favored only by professionals. to compare these systems, spot diagrams (fig. 10) were created for four designs with identical focal ratios but different surface shapes, as reported in [3]. each had a 200 mm aperture, f/2.67 primary, and a focal surface 120 mm behind the primary. diagrams show that dall-kirkham and pressmann-camichel are unsuitable for wide-field imaging due to coma. the ritchey-chrétien offers round star images, ideal for photography, but shows increasing astigmatism beyond 20 mm off-axis and has the strongest field curvature. the classical cassegrain matches newtonian image quality but with more pronounced field curvature. fig. 10 spot diagrams of four different types of 200 mm f/8 cassegrain telescopes [3] 6. catadioptric telescopes catadioptric telescopes (fig. 1) are sophisticated optical instruments that integrate both refractive elements (lenses) and reflective elements (mirrors) to form an image. this hybrid approach leverages the strengths of both refraction and reflection, enabling the correction of various optical aberrations such as spherical aberration, coma, and chromatic aberration. the result is an optical system that delivers high-quality images across a wide field of view. dss vol. 6, no. 1, 2025, pp.49-90 72 the significance of catadioptric telescopes lies in their versatility and performance. by folding the optical path through the use of mirrors, these telescopes achieve a shorter physical length than refracting telescopes of equivalent aperture, making them highly portable a critical advantage for amateur astronomers and field observers. additionally, the incorporation of corrector lenses allows for larger apertures within a smaller package, enhancing light-gathering capability without significantly increasing size or weight. historically, the development of catadioptric telescopes began in the early 20th century. a pivotal advancement came in 1930 with bernhard schmidt’s invention of the schmidt camera, which utilized a spherical primary mirror and an aspheric corrector plate to achieve a wide, aberration-corrected field of view. schmidt’s design addressed spherical aberration effectively, though it required precise fabrication of the corrector plate [60]. building on this foundation, dimitry maksutov introduced the maksutov telescope in 1941 [61]. his design employed a thick meniscus corrector lens to correct spherical aberration in a spherical mirror system. the maksutov telescope is renowned for its compact size and exceptional image quality, particularly suited for high-magnification tasks like planetary observation. its simplicity and effectiveness have made it a staple in optical engineering. the schmidt-cassegrain telescope (fig. 11) presents a fusion of schmidt’s corrector plate with the cassegrain reflector system, featuring a spherical primary mirror and a convex secondary mirror. this configuration folds the optical path, resulting in a compact telescope with a long focal length. the sct balances field of view and image quality, making it a popular choice for visual observation and astrophotography. similarly, the maksutov-cassegrain (fig. 11) adapts the maksutov corrector lens to a cassegrain layout, offering comparable compactness with slightly different optical characteristics. its thicker corrector lens provides robust aberration correction, often yielding superior contrast for specific applications. fig. 11 schmidt-cassegrain and maksutov-cassegrain telescopes [155] dss vol. 6, no. 1, 2025, pp.49-90 73 these instruments have become indispensable in astronomy and beyond, offering a balance of optical excellence and practicality. despite their advantages, catadioptric telescopes are not without challenges. the additional optical surfaces introduced by corrector lenses can lead to light loss and internal reflections if not properly managed. moreover, the manufacturing of precisely corrector elements can be complex and costly. however, technological advancements have largely mitigated these drawbacks, solidifying the catadioptric design’s place in modern optics. recent literature highlights advancements in catadioptric design. the integration of computer-aided design (cad) and ray-tracing software has enabled precise optimization of optical elements [62]. aspheric surfaces, once challenging to produce, are now more feasible thanks to modern manufacturing techniques [54]. additionally, innovations in materials, such as advanced coatings and lightweight composites, have improved performance and durability [5,6]. contemporary research also explores specialized catadioptric systems for space applications. for example, the kepler space telescope utilized a schmidt-based design to survey exoplanets, demonstrating the adaptability of catadioptric principles to the stringent requirements of space missions [63]. 6.1 methods of design designing a catadioptric telescope is a meticulous process that combines optical theory, computational tools, and practical engineering. the main goal is to create a system that meets specific performance criteria, such as aperture size, focal length, and field of view, while minimizing main aberrations and ensuring manufacturability. 6.1.1 design process overview the telescope design begins with defining the telescope’s specifications based on its intended use. for instance, an astronomical telescope might prioritize a larger aperture and longer focal length, while a terrestrial spotting scope may emphasize compactness and a wide field of view. once these parameters are set, an appropriate catadioptric configuration is selected, such as a representative schmidt-cassegrain or maksutov-cassegrain (fig. 11). 6.1.2 schmidt-cassegrain design in the schmidt-cassegrain configuration (fig. 11), the primary mirror is spherical, simplifying production compared to parabolic mirrors. a schmidt corrector plate, placed at the telescope’s entrance, corrects for spherical aberration. this plate has an aspheric profile, carefully calculated to adjust the paths of incoming light rays so they converge accurately at the focal plane. the secondary mirror, typically convex, reflects light through a central hole in the primary mirror to the eyepiece or detector, folding the optical path and reducing the telescope’s length [3]. 6.1.3 maksutov-cassegrain design the maksutov-cassegrain (fig. 11) employs a meniscus corrector lens instead of a plate. this thick, curved lens corrects spherical aberration while maintaining a compact design. the secondary mirror in a maksutovcassegrain can be implemented in two ways: it can be a separate, precisely figured optical element mounted within the telescope tube, or it can be an aluminized spot directly applied to the central area of the rear surface of the meniscus corrector lens itself. this integrated secondary mirror offers the significant advantages of simplifying the alignment process [61]. 6.2 practical considerations beyond optics, the design must address mechanical stability, alignment ease, and manufacturing feasibility. the corrector plate or lens requires precise grinding and polishing to achieve its aspheric shape, a process that has been refined with modern cnc machinery [54]. baffling is also critical to control stray light, as the folded optical path can introduce unwanted reflections if not properly shielded. dss vol. 6, no. 1, 2025, pp.49-90 74 6.3 testing and alignment once constructed, the telescope undergoes rigorous testing often using interferometry or star tests to verify performance. the alignment of optical elements is adjusted to minimize residual aberrations, ensuring the system meets its design goals. 6.4 applications catadioptric telescopes serve a diverse array of purposes, capitalizing on their compact size, large apertures, and optical versatility. in astronomy, catadioptric designs dominate the amateur market. telescopes like the celestron’s schmidtcassegrain series are prized for their portability and ability to observe a range of celestial targets, from planets to galaxies. their folded design allows for large apertures (e.g., 8-14 inches) in a manageable size, ideal for transport to dark-sky sites. professionally, schmidt telescopes have been instrumental in wide-field surveys, such as the palomar observatory sky survey, mapping vast regions of the sky with high fidelity [5,6]. the kepler space telescope stands as a prominent example of the successful application of catadioptric optical design in space-based astronomy. launched by nasa in 2009, kepler employed a modified schmidt telescope configuration. this design provided a wide, flat field of view with minimal optical distortion, making it ideal for photometric observations. kepler’s mission was to detect exoplanets by continuously monitoring the brightness of over 150,000 stars within a fixed field of the milky way. its optical system was specifically optimized to measure minute changes in stellar brightness caused by the transit method a planet passing in front of its host star, causing a slight and periodic dimming. thanks to this innovative catadioptric design, kepler revolutionized the field of exoplanetary science, leading to the discovery of thousands of exoplanets, many of which are earth-sized and located in the habitable zones of their stars [63]. for terrestrial use, catadioptric spotting scopes provide high magnification and clarity in a compact form. birdwatchers and nature enthusiasts benefit from their portability, while surveillance and military applications leverage their long-range capabilities. in scientific contexts, catadioptric systems appear in specialized equipment. photolithography machines, used in semiconductor manufacturing, employ catadioptric projection optics to image intricate patterns onto wafers with sub-micron precision [62]. similarly, laser beam expanders and optical alignment tools utilize catadioptric principles for their aberration-corrected performance. with the advent of digital imaging, catadioptric telescopes paired with ccd cameras have become powerful tools for astrophotography. their design supports the high resolution and light sensitivity required for capturing detailed images of celestial objects. looking forward, catadioptric telescopes are poised for further advancement. the integration of adaptive optics could enhance their performance for ground-based astronomy by compensating for atmospheric distortion. innovations in materials, such as lightweight carbon fiber tubes and advanced coatings, promise greater portability and efficiency. additionally, as digital imaging continues to evolve, catadioptric designs may be optimized further for astrophotography and automated sky surveys. catadioptric telescopes represent a mature yet dynamic field, with a rich history and a promising future, continuing to push the boundaries of optical engineering. 6.6 image quality in schmidt-cassegrain catadioptric telescope the schmidt-cassegrain telescope (sct) is popular among amateur astronomers due to its compact design, portability, closed tube, and good color correction. most commercial models have an f/10 focal ratio, but many users don’t realize scts belong to a broad family of designs with various configurations. despite having only three components, a primary mirror, a secondary mirror, and a schmidt corrector, the sct allows many design variations. these include different corrector placements, mirror shapes (spherical or aspheric), dss vol. 6, no. 1, 2025, pp.49-90 75 and focal positions (in front of or behind the primary). a key difference from the classical cassegrain reflecting telescope is the schmidt corrector, which removes axial spherical aberration (using a corrector plate), though off-axis aberrations like coma and astigmatism require specific designs to correct. practically, scts fall into two main categories: visual and photographic. visual scts feature strongly curved focal surfaces and small secondary mirrors (<30% of the primary diameter), which makes them unsuitable for wide-field photography without additional correction. photographic scts are designed for flat-field imaging, requiring nearly equal radii of curvature for both mirrors. this results in large secondary mirrors (45–60% of the primary diameter) and poor performance for visual use at high magnifications. "visual" schmidt-cassegrain telescopes feature a curved focal surface and a moderately sized secondary mirror, making them well-suited for visual observation. in this compact setup, the secondary mirror is attached to the inner surface of the schmidt corrector lens. the primary mirror has an f/2 focal ratio, with a secondary magnification of 5, comparable to standard commercial 200 mm f/10 telescope systems. fig. 12 presents spot diagrams for a 200 mm f/10 schmidt-cassegrain with spherical mirrors (as reported in [3]), both onand off-axis, for flat and curved focal surfaces. while axial sharpness is excellent, off-axis performance suffers from strong coma, comparable to a 200 mm f/5 newtonian. this makes compact scts with spherical mirrors unsuitable for wide fields. to reduce coma while maintaining sharp axial images, designers may: (a) aspherize the primary, (b) aspherize the secondary, (c) aspherize both, or (d) reposition the schmidt corrector (abandoning compactness). the most common solution is aspherizing the secondary; using both aspheric mirrors is rare in amateur telescopes. fig. 12 spot diagrams for a 200 mm f/10 all-spherical schmidt-cassegrain telescope [3] dss vol. 6, no. 1, 2025, pp.49-90 76 figure 13 shows spot diagrams for an optimized 200 mm f/10 schmidt-cassegrain with an aspherized secondary, as reported in [3]. at the flat focal surface (top row), sharp images are limited to the central 20 mm about the size of the full moon with increasing blur beyond that. at the curved focal surface (bottom row), image quality is diffraction-limited over a wide area, offering excellent visual performance. photographic results can improve with curved film or a field flattener. in this design, the schmidt corrector provides 83.42% of the spherical aberration correction, with the rest handled by the aspheric secondary [3]. fig. 13 spot diagrams for an optimized (secondary mirror aspherized) 200 mm f/10 sct [3] figure 14 shows spot diagrams for red, green, and blue light in the sct system optimized for green, as reported in [3]. the remaining color error is due to spherochromatism the change of spherical aberration with wavelength. all colors focus on the neutral zone where the corrective lens has no refractive power. elsewhere, refraction varies by wavelength, causing color differences. in this system, color aberration is about five times less than in a comparable f/15 fraunhofer doublet refractor of the same aperture. the main drawback of this design is the large central obstruction from the secondary mirror and its holder, which is 34% of the entrance pupil diameter, larger than ideal for observing low-contrast objects like planetary details. reducing the secondary size by using a slower system (f/15 or f/20 instead of f/10) shrinks the field of view, making the telescope less versatile. additionally, cassegrain telescopes need baffle tubes to block stray light, which prevents reducing the central obstruction below about 30% in a 200 mm instrument [3]. fig. 14 color correction for an optimized 200 mm f/10 sct [3] comparing the off-axis performance of the optimized visual schmidt-cassegrain telescope to a similar f/10 two-mirror classical cassegrain reflector shows the latter has spot diagrams about four times larger. the sct’s better performance is due to two factors: moving the entrance pupil from the primary mirror to the schmidt corrector and adding an extra optical surface, which allows better correction of aberrations across three surfaces instead of two [3]. flat-field schmidt-cassegrain telescope design is also discussed in reference [3]. table 4 provides paameters for this 200 mm f/4 telescope. dss vol. 6, no. 1, 2025, pp.49-90 77 table 4 data for 200mm f/4 schmidt-cassegrain telescope (dimensions in millimeters) [3] corrector radius, first surface flat thickness 4 glass 517643 paraxial radius, second surface -83250 radius of neutral zone 86.6% of 100 mm relative power 50.5% distance to primary 977.2 primary radius of curvature -845.6 distance to secondary -231.6 secondary radius of curvature -809.7 distance to focal surface 358.285 radius of focal surface flat effective focal length 800 geometric focal ratio f/4 diameters schmidt corrector 216 stop 200 primary mirror 220 secondary mirror 110 distance, stop to corrector 300 1° field 14.0 this is essentially a variant of the slevogt flat-field telescope design, where a compromise is achieved by positioning a 200 mm diameter stop 300 mm behind the corrector. this causes the primary mirror's diameter to be roughly the same as the corrector's. for visual use, a large obstruction reduces contrast by spreading light into diffraction rings, which is undesirable. however, in photography, a 55% central obstruction (present in this system) is acceptable since over 80% of the light remains concentrated in the airy disk and first diffraction ring, well within photographic sharpness limits. additionally, the large secondary mirror eliminates the need for baffling by blocking stray light due to its size and the long tube design [3]. fig. 15 spot diagrams for a flat-field 200 mm f/4 schmidt-cassegrain telescope [3] dss vol. 6, no. 1, 2025, pp.49-90 78 fig. 15 shows spot diagrams for this flat-field 200 mm f/4 schmidt-cassegrain telescope. it can be seen that this design meets the 0.025 mm criterion over the entire 60 mm diameter flat field under consideration, and that lateral color is within the same limit as well. 6.7 image quality in maksutov-cassegrain type catadioptric telescopes john gregory introduced the f/23 gregory maksutov-cassegrain, a compact catadioptric telescope with spherical optics and an aluminized secondary spot on the meniscus corrector, making the design accessible to amateurs. his f/15 version improved color correction, requiring slight aspherization. later adaptations refined the design for both visual use and astrophotography. this section reviews several 200 mm aperture models and assesses their optical performance, as presented in reference [3]. in this regard, fig. 16 presents six representative maksutov systems, providing a basis to discuss degrees of freedom the adjustable optical parameters like curvature, spacing, thickness, glass type, or aspheric surfaces. effective image correction requires at least as many degrees of freedom as the aberrations being corrected. the gregory maksutov-cassegrain (fig. 16) shows notable coma and astigmatism, as evident in the spot diagrams (fig. 17). these aberrations can't be corrected in the mentioned design because the secondary mirror shares the curvature of the corrector’s back surface. adding a degree of freedom, such as an independently curved secondary, is necessary for improvement. one solution, used by some manufacturers, involves grinding the corrector center differently, but this is complex for amateurs. a simpler method is the rumak design (introduced by harrie rutten), which attaches a separate convex secondary. also, an f/15 system, the rumak offers better off-axis performance, improved color correction, and a flatter field (fig. 17). both systems perform near the diffraction limit on-axis in red, green, and blue light, but the rumak clearly outperforms off-axis. the gregory design also suffers from considerable spherochromatism. the rumak design also has drawbacks: it requires a longer optical tube and a larger secondary mirror compared to the gregory maksutov. designing a rumak-type system with the same tube length as the gregory is feasible, but it demands an additional degree of freedom. this can be achieved by aspherizing one of the optical surfaces either the corrector, primary, or secondary mirror. however, producing aspheric surfaces is complex and typically impractical for most applications, making this solution less appealing [3]. additional design flexibility can be achieved by adjusting the spacing between the corrector and secondary mirror, especially in fast maksutov-cassegrain systems (faster than f/8) with all-spherical surfaces. this approach is used in designs like the simak and sigler (fig. 18). however, for systems faster than f/4, spherical surfaces alone lead to excessive aberrations. in the f/2.5 companar, klaas compaan (fig. 19) minimized chromatic aberration by adding a weak positive lens in front of the corrector. to correct residual spherical aberration, the lens was slightly aspherized a step only necessary for systems faster than f/2.85 [3]. the characteristics (radius of curvature, axial thickness, medium type, focal length) of the six maksutov systems are given in table 5, while their spot diagrams are shown in figs. 17, 18 and 19. among the maksutov-cassegrain telescopes reviewed, only the companar features a flat focal surface, having been designed specifically for astrophotography. other models are suitable for both photographic and visual use, where keeping the secondary mirror small is important to reduce central obstruction. the companar achieves its flat field by nearly matching the radii of curvature of the primary and secondary mirrors. however, this results in a large secondary mirror (60% of the aperture), causing a 36% light loss at the center and up to 35% at the edges. despite this, the large obstruction has minimal effect on image sharpness due to the compact diffraction pattern at f/2.5. compared to traditional maksutov cameras, flat-field designs like the companar are more complex, requiring larger optics and in some cases, a spider to support the secondary mirror. however, the companar avoids the need for a baffle thanks to its large secondary, which effectively blocks stray light. dss vol. 6, no. 1, 2025, pp.49-90 79 fig. 16 schemes of six maksutov-cassegrain telescope systems [3] dss vol. 6, no. 1, 2025, pp.49-90 80 fig. 17 spot diagrams for the gregory-maksutov and rumak telescopes [3] when comparing maksutovand schmidt-cassegrain designs, the maksutov generally requires larger elements due to the stronger outward bending of rays by its negative corrector lens. both the aspheric companar and the f/4 schmidt-cassegrain offer excellent image quality, but their construction is challenging, making them suitable only for highly skilled amateurs seeking top-tier, wide-field astrophotographic performance [3]. dss vol. 6, no. 1, 2025, pp.49-90 81 fig. 18 spot diagrams for the simak and sigler maksutov systems [3] fig. 19 spot diagrams for the comapanar systems [3] dss vol. 6, no. 1, 2025, pp.49-90 82 table 5. three 200 mm maksutov-cassegrain systems (dimensions in millimeters) [3] system gregory rumak simak sigler f/8.0 companar (aspheric) companar (aspheric) focal ratio f/15 f/15 f/5.6 f/8 f/2.5 f/2.8 r₁ radius of curvature -219.413 -334.956 -217.465 -297.709 11070 12300 t₁ axial distance 17.347 20 19.425 20.6 10.0 11.1 m₁ medium 517642 517642 517642 517642 517642 517642 r₂ -229.6 -346.673 -229.025 -309.455 -11070 -12300 t₂ 403.653 605.8 355.575 693.582 210.0 233.3 m₂ air air air air air air r₃ -980.453 -1592.2 -847.2 -1311.818 -210.0 -233.3 t₃ -403.653 -589.7 -289.675 -413.473 18 20.1 m₃ air air air air 517643 517643 r₄ -229.6 -598.072 -451.75 -847.091 -228.0 -253.4 t₄ 620.679 832.12 388.222 631.75 388.175 439.88 m₄ air air air air air air r₅ -520.84 -584.13 t₅ -140.0 -155.56 m₅ air air r₆ -500.68 -562.44 t₆ 240.283 275.19 m₆ air air effective focal length 3000 2964 1122 1595 504 572 1° field 52.4 51.7 19.6 27.8 8.8 10.0 7. conclusions in summary, this review has explored the design characteristics and image quality aspects of the three main categories of amateur astronomical telescopes: refractors, reflectors, and catadioptric systems. drawing on an extensive literature base of over 150 references, the analysis has addressed key optical features, strengths, and limitations of each design. comparative evaluation has highlighted how these instruments differ in terms of optical performance, ease of use, portability, and maintenance, as well as their effectiveness in both visual observation and astrophotography. particular emphasis was placed on the management of aberrations, field curvature, and diffraction elements central to achieving high image quality. based on these findings, practical guidance is offered for users with different observational goals, whether focused on planetary detail, deep-sky imaging, or introductory stargazing. this synthesis of theory and application provides a useful framework for selecting the most suitable telescope type according to individual needs and interests. below are given general conclusions that can be drawn. refractor telescopes design: uses lenses (typically a doublet or triplet objective). optical characteristics:  excellent contrast and sharpness, especially for planetary and lunar observation.  prone to chromatic aberration unless apochromatic lenses are used (which are costly).  high light throughput (no central obstruction).  low maintenance – sealed tube keeps optics clean and aligned.  heavy and long tubes for larger apertures; expensive in large sizes. dss vol. 6, no. 1, 2025, pp.49-90 83 reflector telescopes – newtonian type design: uses a parabolic primary mirror and a flat secondary mirror. optical characteristics:  very good image quality, no chromatic aberration.  coma off-axis in fast focal ratios.  slight contrast reduction due to central obstruction.  requires collimation; open tube prone to dust and thermal currents.  cost-effective; large apertures are affordable. reflector telescopes – cassegrain type design: uses a concave primary and convex secondary mirror. optical characteristics:  high resolution; suitable for planetary and deep-sky imaging.  can have field curvature and coma; often corrected in compound variants.  larger central obstruction than newtonians.  closed tube (when combined with corrector); mirrors need alignment. schmidt-cassegrain telescope (sct) design: combines spherical primary mirror, schmidt corrector plate, and secondary mirror. optical characteristics:  good all-around performance; minor spherical aberration corrected.  field curvature and coma; not ideal for wide-field astrophotography without a corrector.  moderate light throughput due to central obstruction and multiple reflections.  compact and lightweight for aperture size.  needs occasional collimation; the corrector plate helps seal the system. maksutov-cassegrain telescope (mct) design: uses a spherical primary mirror and meniscus corrector with a built-in secondary. optical characteristics:  very sharp and high contrast; excellent for lunar and planetary observation.  very well corrected; minimal chromatic and spherical aberration.  slightly lower light throughput due to the thick corrector and central obstruction.  very compact; slower focal ratios (e.g., f/12–f/15).  rarely needs collimation; sealed system is low maintenance.  long cool-down time due to thick corrector; narrow field of view. below is given quick comparison table, based on previous conclusions. characteristic refractor newtonian cassegrain schmidt-cassegrain maksutov-cassegrain chromatic aberration yes (unless apo) none none none (minor sa) minimal contrast excellent good moderate good excellent field of view moderate wide narrow moderate narrow portability low moderate moderate moderate high high maintenance very low high moderate low moderate very low astrophotography good (apo) very good (fast) good good (with corrector) fair (narrow field) dss vol. 6, no. 1, 2025, pp.49-90 84 declaration of competing interest the authors declare that they have no known financial or non-financial competing interests in any material discussed in this paper. funding information no funding was received from any financial organization to conduct this research. references [1] j. cheng, the principles of astronomical telescope design. new york, ny, usa: springer, 2009. 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