EUROPEAN JOURNAL OF PURE AND APPLIED MATHEMATICS 2025, Vol. 18, Issue 4, Article Number 6753 ISSN 1307-5543 – ejpam.com Published by New York Business Global Type-2 Neutrosophic Aczel-Alsina Hamy Mean Aggregation Operators for Multiple-Attribute Decision-Making Problems Karahan Kara1,2, Galip Cihan Yalçın2, Vladimir Simic3,∗, Dragan Pamucar4,5,6,∗ 1 Department of Business, Faculty of Economics and Administrative Sciences, İzmir Democracy University, 35140 İzmir, Türkiye 2 Department of Business, Faculty of Economics and Administrative Sciences, OSTIM Technical University, 06374 Ankara, Türkiye 3 Széchenyi István University, Egyetem tér 1, 9026 Győr, Hungary 4 Department of Applied Mathematical Science, College of Science and Technology, Korea University, Sejong, 30019, Republic of Korea 5 Faculty of Engineering, Doğuş University, 34775 Umraniye, Istanbul, Türkiye 6 UNEC Applied Artificial Intelligence Research Center, Azerbaijan State University of Economics (UNEC), Baku, Azerbaijan Abstract. This study introduces novel aggregation operators for Type-2 Neutrosophic Number Sets (T2NNs) by integrating the Hamy Mean with the Aczel-Alsina t-norm and t-conorm opera- tions. The Hamy Mean, a mathematical averaging technique, is particularly effective in contexts characterized by uncertainty and ambiguity, such as fuzzy set theory. Leveraging this, two aggre- gation operators are proposed: the T2NN Aczel-Alsina Hamy Mean (T2NNAAHM) and the T2NN Aczel-Alsina Weighted Hamy Mean (T2NNAAWHM). The study presents the formal definitions, underlying operations, theoretical foundations, and proofs of these operators. Their applicabil- ity is demonstrated through a Multiple-Attribute Decision-Making (MADM) case study, followed by comparative analyses to evaluate their performance and robustness. The findings indicate that T2NNAAHM and T2NNAAWHM are effective tools for decision-making problems involving T2NNs. This research contributes to the field by providing rigorously defined aggregation operators that address uncertainty and ambiguity, thereby enhancing the methodological toolkit available for complex decision-making scenarios. 2020 Mathematics Subject Classifications: 03B52, 03E72 Key Words and Phrases: Type-2 neutrosophic number, Aczel-Alsina, Hamy mean, T2NNAAHM, T2NNAAWHM ∗Corresponding author. ∗Corresponding author. DOI: https://doi.org/10.29020/nybg.ejpam.v18i4.6753 Email addresses: karahan.kara@idu.edu.tr (K. Kara), galipcihan.yalcin@ostimteknik.edu.tr (G. C. Yalçın), simic.vladimir@sze.hu (V. Simic), dpamucar@gmail.com (D. Pamucar) https://www.ejpam.com 1 Copyright: © 2025 The Author(s). (CC BY-NC 4.0) K. Kara et al. / Eur. J. Pure Appl. Math, 18 (4) (2025), 6753 2 of 20 1. Introduction The concept of neutrosophic sets, which comprehensively extends and enhances the treatment of uncertainty beyond the scope of classical set theory, is introduced into the literature by Smarandache [1]. Neutrosophic sets are defined with consideration for three values: truth, indeterminacy, and falsity. These sets consist of three components: T- membership, I-membership, and F-membership. T-membership represents the degree of an element’s belonging to the set, while I-membership characterizes the uncertainty regarding the element’s membership. F-membership quantifies the degree of non-membership of an element. Neutrosophic sets go beyond the binary consideration of membership and non- membership, considering the level of uncertainty, thus enabling calculations based on complex probabilities. Type-2 Neutrosophic Number Sets (T2NNs) are developed as an extension of neutro- sophic sets [2] to handle greater levels of uncertainty. T2NNs enable information process- ing by going beyond Type-1 Neutrosophic Sets (T1NS). In T2NNs, membership functions exist at two levels: Primary Membership Functions (PMFs) and Secondary Membership Functions (SMFs). PMFs represent the primary degree of truth, indeterminacy, and fal- sity of an element, while SMFs provide a secondary layer of truth, indeterminacy, and falsity degrees. This dual-layer membership function structure allows for the modeling of complex problems where boundaries between membership, non-membership, and indeter- minacy are not well-defined. In the literature, T2NNs have been applied in various decision problems, utilizing dif- ferent ranking methods, such as supplier selection [2], public transportation pricing system selection [3], sustainable policies selection [4], smart technology selection [5], sustainable route selection [6], segmentation of brain tumor tissue structures [7], energy blockchain system selection [8], selection of second-hand chemical tankers [9], Ro-Ro vessel selec- tion [10], offshore wind farm site selection [11], autonomous vehicle type selection [12], green supplier selection [13], architecture selection for 5G-radio access networks [14], and evaluation of container port sustainability [15]. Notably, the Type-2 neutrosophic num- bers weighted averaging (T2NNWA) operator has been frequently employed in T2NNs aggregation in research [3–7, 10, 12, 13, 16–23] The Aczel–Alsina t-norm and t-conorm operations, together with the Hamy Mean, are fundamental tools for aggregation in fuzzy set theory [24]. Within the framework of neutrosophic sets, these operations are frequently utilized across various averaging techniques [25–28] and are often combined with the Hamy Mean to enhance aggrega- tion performance [29, 30]. The main objective of this study is to develop novel aggre- gation operators for Type-2 Neutrosophic Numbers (T2NNs) based on the Aczel–Alsina t-norm and t-conorm operations in conjunction with the Hamy Mean, specifically de- signed for Multiple-Attribute Decision-Making (MADM) applications [31, 32]. To achieve this goal, two new aggregation operators are proposed: the Type-2 Neutrosophic Numbers Aczel–Alsina Hamy Mean operator (T2NNAAHM) and the Type-2 Neutrosophic Numbers Aczel–Alsina Weighted Hamy Mean operator (T2NNAAWHM). The key contributions of this study are as follows: K. Kara et al. / Eur. J. Pure Appl. Math, 18 (4) (2025), 6753 3 of 20 (i) Explaining the applications of Aczel–Alsina operations based on T2NNs in MADM problems; (ii) Developing Hamy Mean-based aggregation operators for T2NNs; (iii) Introducing both weighted and unweighted aggregation operators for T2NNs using Aczel–Alsina operations and Hamy Mean; (iv) Defining and proving the newly developed aggregation operators; (v) Conducting robustness tests for the obtained findings and aggregation operators; (vi) Comparing the results obtained with T2NNWA operator results. This paper consists of eight sections. The second section elaborates on Aczel-Alsina operations based on T2NNs. The third section discusses Hamy Mean-based Aczel-Alsina operations of T2NNs. The fourth section presents the MADM approach with T2NNAAHM and T2NNAAWHM operators. The fifth section applies the aggregation operators with illustrative examples. In the sixth section, comparative analyses are conducted. The sev- enth section contains the implications of this research. The eight section is also conclusion section. 2. Aczel-Alsina Operations based on Type-2 Neutrosophic Number Sets In this section, we furnish detailed definitions encompassing the Aczel-Alsina t-norm and t-conorm, along with a comprehensive exposition of the corresponding mathematical operations. Definition 1. The Aczel-Alsina t-norm is presented in Eq. (1), and the Aczel-Alsina t-conorm is expressed in Eq. (2) [33]: T ξ AA(x, y) =  TD(x, y), if ξ = 0 min(x, y), if ξ = ∞ e − ( (− ln(x))ξ+(− ln(y))ξ )1/ξ , otherwise. (1) T ∗ξ AA(x, y) =  SD(x, y), if ξ = 0 max(x, y), if ξ = ∞ e − ( (− ln(1−x))ξ+(− ln(1−y))ξ )1/ξ , otherwise. (2) For each parameter ξ ∈ [0,∞];T ξ AA and T ∗ξ AA are dual to each other. We will delve into the fundamental operational laws of the Aczel-Alsina t-norm and Aczel-Alsina t-conorm for T2NNs. The Aczel-Alsina product for the Aczel-Alsina t-norm is defined in Eq. (3). The Aczel-Alsina sum for the Aczel-Alsina t-norm is defined in Eq. (4): Ñ1 ⊗ Ñ2 = ⟨ T ( [T (T (Ñ1)(z), T (T (Ñ2)(z)))], [T (I(Ñ1)(z), T (I(Ñ2)(z)))], [T (F (Ñ1)(z), T (F (Ñ2)(z)))] ) , T ∗([I(T (Ñ1)(z), I(T (Ñ2)(z)))], [I(I(Ñ1)(z), I(I(Ñ2)(z)))], [I(F (Ñ1)(z), I(F (Ñ2)(z)))] ) , T ∗([F (T (Ñ1)(z), F (T (Ñ2)(z)))], [F (I(Ñ1)(z), I(I(Ñ2)(z)))], [F (F (Ñ1)(z), F (F (Ñ2)(z)))] ) ⟩ (3) K. Kara et al. / Eur. J. Pure Appl. Math, 18 (4) (2025), 6753 4 of 20 Ñ1 ⊕ Ñ2 = ⟨ T ∗ ( [T (T (Ñ1)(z), T (T (Ñ2)(z)))], [T (I(Ñ1)(z), T (I(Ñ2)(z)))], [T (F (Ñ1)(z), T (F (Ñ2)(z)))] ) , T ∗ ( [I(T (Ñ1)(z), I(T (Ñ2)(z)))], [I(I(Ñ1)(z), I(I(Ñ2)(z)))], [I(F (Ñ1)(z), I(F (Ñ2)(z)))] ) , T ( [F (T (Ñ1)(z), F (T (Ñ2)(z)))], [F (I(Ñ1)(z), I(I(Ñ2)(z)))], [F (F (Ñ1)(z), F (F (Ñ2)(z)))] ) ⟩ (4) Definition 2. Suppose that Ñ, Ñ1, and Ñ2 are three T2NNs over the universe Z. The operations among these three T2NNs based on Aczel-Alsina T and Aczel-Alsina T ∗ are described as follows (ω > 0): (i) Ñ1 ⊗ Ñ2 = [ e− ( (− lnT (T (Ñ1)(z))) ξ+(− lnT (T (Ñ2)(z))) ξ )1/ξ , e− ( (− lnT (I(Ñ1)(z))) ξ+(− lnT (I(Ñ2)(z))) ξ )1/ξ , e− ( (− lnT (F (Ñ1)(z))) ξ+(− lnT (F (Ñ2)(z))) ξ )1/ξ ; 1− e− ( (− ln I(T (Ñ1)(1−z)))ξ+(− ln I(T (Ñ2)(1−z)))ξ )1/ξ , 1− e− ( (− ln I(I(Ñ1)(1−z)))ξ+(− ln I(I(Ñ2)(1−z)))ξ )1/ξ , 1− e− ( (− ln I(F (Ñ1)(1−z)))ξ+(− ln I(F (Ñ2)(1−z)))ξ )1/ξ ; 1− e− ( (− lnF (T (Ñ1)(1−z)))ξ+(− lnF (T (Ñ2)(1−z)))ξ )1/ξ , 1− e− ( (− lnF (I(Ñ1)(1−z)))ξ+(− lnF (I(Ñ2)(1−z)))ξ )1/ξ , 1− e− ( (− lnF (F (Ñ1)(1−z)))ξ+(− lnF (F (Ñ2)(1−z)))ξ )1/ξ ] (ii) Ñ1 ⊕ Ñ2 = [ 1− e− ( (− lnT (T (Ñ1)(1−z)))ξ+(− lnT (T (Ñ2)(1−z)))ξ )1/ξ , 1− e− ( (− lnT (I(Ñ1)(1−z)))ξ+(− lnT (I(Ñ2)(1−z)))ξ )1/ξ , 1− e− ( (− lnT (F (Ñ1)(1−z)))ξ+(− lnT (F (Ñ2)(1−z)))ξ )1/ξ ; 1− e− ( (− ln I(T (Ñ1)(1−z)))ξ+(− ln I(T (Ñ2)(1−z)))ξ )1/ξ , 1− e− ( (− ln I(I(Ñ1)(1−z)))ξ+(− ln I(I(Ñ2)(1−z)))ξ )1/ξ , 1− e− ( (− ln I(F (Ñ1)(1−z)))ξ+(− ln I(F (Ñ2)(1−z)))ξ )1/ξ ; e− ( (− lnF (T (Ñ1)(z))) ξ+(− lnF (T (Ñ2)(z))) ξ )1/ξ , e− ( (− lnF (I(Ñ1)(z))) ξ+(− lnF (I(Ñ2)(z))) ξ )1/ξ , e− ( (− lnF (F (Ñ1)(z))) ξ+(− lnF (F (Ñ2)(z))) ξ )1/ξ ] (iii) ωÑ = [ 1− e− ( (ω(− lnT (T (Ñ))(1−z)))ξ )1/ξ , 1− e− ( (ω(− lnT (I(Ñ))(1−z)))ξ )1/ξ , 1− e− ( (ω(− lnT (F (Ñ))(1−z)))ξ )1/ξ ; e− ( (ω(− ln I(T (Ñ))(z)))ξ )1/ξ , e− ( (ω(− ln I(I(Ñ))(z)))ξ )1/ξ , e− ( (ω(− ln I(F (Ñ))(z)))ξ )1/ξ ; e− ( (ω(− lnF (T (Ñ))(z)))ξ )1/ξ , e− ( (ω(− lnF (T (Ñ))(z)))ξ )1/ξ , e− ( (ω(− lnF (F (Ñ))(z)))ξ )1/ξ ] (iv) Ñω = [ e− ( (ω(− lnT (T (Ñ))(z)))ξ )1/ξ , e− ( (ω(− lnT (I(Ñ))(z)))ξ )1/ξ , e− ( (ω(− lnT (F (Ñ))(z)))ξ )1/ξ ; 1− e− ( (ω(− ln I(T (Ñ))(1−z)))ξ )1/ξ , 1− e− ( (ω(− ln I(I(Ñ))(1−z)))ξ )1/ξ , 1− e− ( (ω(− ln I(F (Ñ))(1−z)))ξ )1/ξ ; 1− e− ( (ω(− lnF (T (Ñ))(1−z)))ξ )1/ξ , 1− e− ( (ω(− lnF (T (Ñ))(1−z)))ξ )1/ξ , 1− e− ( (ω(− lnF (F (Ñ))(1−z)))ξ )1/ξ ] Example 1: Ñ = ⟨(0.20, 0.20, 0.10), (0.65, 0.80, 0.85), (0.45, 0.80, 0.70)⟩, Ñ1 = ⟨(0.35, 0.35, 0.10), (0.50, 0.75, 0.80), (0.50, 0.75, 0.65)⟩, Ñ2 = ⟨(0.40, 0.30, 0.35), (0.50, 0.45, 0.60), (0.45, 0.40, 0.60)⟩ be three T2NNs over the universe Z. Then, the Aczel-Alsina operations using Definition 2 can be applied for ξ = 2 and ω = 3. (a) Ñ1 ⊗ Ñ2 = [ e− ( (− ln 0.35)2+(− ln 0.40)2 )1/2 , e− ( (− ln 0.35)2+(− ln 0.30)2 )1/2 , e− ( (− ln 0.10)2+(− ln 0.35)2 )1/2 ; 1− e− ( (− ln(1−0.50))2+(− ln(1−0.50))2 )1/2 , 1− e− ( (− ln(1−0.75))2+(− ln(1−0.45))2 )1/2 , 1− e− ( (− ln(1−0.80))2+(− ln(1−0.60))2 )1/2 ; 1− e− ( (− ln(1−0.50))2+(− ln(1−0.45))2 )1/2 , 1− e− ( (− ln(1−0.75))2+(− ln(1−0.40))2 )1/2 , 1− e− ( (− ln(1−0.65))2+(− ln(1−0.60))2 )1/2 ] Result: 〈(0.25,0.20,0.08),(0.62,0.78,0.84),(0.60,0.77,0.75)〉. K. Kara et al. / Eur. J. Pure Appl. Math, 18 (4) (2025), 6753 5 of 20 (b) Ñ1 ⊕ Ñ2 = [ 1− e− ( (− ln(1−0.35))2+(− ln(1−0.40))2 )1/2 , 1− e− ( (− ln(1−0.35))2+(− ln(1−0.30))2 )1/2 , 1− e− ( (− ln(1−0.10))2+(− ln(1−0.35))2 )1/2 ; 1− e− ( (− ln(1−0.50))2+(− ln(1−0.50))2 )1/2 , 1− e− ( (− ln(1−0.75))2+(− ln(1−0.45))2 )1/2 , 1− e− ( (− ln(1−0.80))2+(− ln(1−0.60))2 )1/2 ; e− ( (− ln 0.50)2+(− ln 0.45)2 )1/2 , e− ( (− ln 0.75)2+(− ln 0.40)2 )1/2 , e− ( (− ln 0.65)2+(− ln 0.60)2 )1/2 ] Result: 〈(0.49,0.43,0.36),(0.62,0.78,0.84),(0.35,0.38,0.51)〉. (c) ωÑ = [ 1− e− ( (3(− ln(1−0.20)))2 )1/2 , 1− e− ( (3(− ln(1−0.20)))2 )1/2 , 1− e− ( (3(− ln(1−0.10)))2 )1/2 ; e− ( (3(− ln 0.65))2 )1/2 , e− ( (3(− ln 0.80))2 )1/2 , e− ( (3(− ln 0.85))2 )1/2 ; e− ( (3(− ln 0.45))2 )1/2 , e− ( (3(− ln 0.80))2 )1/2 , e− ( (3(− ln 0.70))2 )1/2 ] Result: 〈(0.32,0.32,0.17),(0.47,0.68,0.75),(0.25,0.68,0.54)〉. (d) Ñω = [ e− ( (3(− ln 0.20))2 )1/2 , e− ( (3(− ln 0.20))2 )1/2 , e− ( (3(− ln 0.10))2 )1/2 ; 1− e− ( (3(− ln(1−0.65)))2 )1/2 , 1− e− ( (3(− ln(1−0.80)))2 )1/2 , 1− e− ( (3(− ln(1−0.85)))2 )1/2 ; 1− e− ( (3(− ln(1−0.45)))2 )1/2 , 1− e− ( (3(− ln(1−0.80)))2 )1/2 , 1− e− ( (3(− ln(1−0.70)))2 )1/2 ] Result: 〈(0.06,0.06,0.02),(0.84,0.94,0.96),(0.64,0.94,0.88)〉. Theorem 1: Suppose that Ñ1 and Ñ2 are two type-2 neutrosophic number sets over the universe Z, then: (a) Ñ1 ⊕ Ñ2 = Ñ2 ⊕ Ñ1 (b) Ñ1 ⊗ Ñ2 = Ñ2 ⊗ Ñ1 (c) ω(Ñ1 ⊕ Ñ2) = ωÑ1 ⊕ ωÑ2, for ω > 0 (d) (Ñ1 ⊗ Ñ2) ω = Ñω 1 ⊗ Ñω 2 , for ω > 0 (e) ω1Ñ1 ⊕ ω2Ñ1 = (ω1 + ω2)Ñ1, for ω1, ω2 > 0 (f) Ñω1 1 ⊗ Ñω2 1 = Ñω1+ω2 1 , for ω1, ω2 > 0 Proof. [Proof for Ñ1 ⊕ Ñ2 = Ñ2 ⊕ Ñ1] Ñ1 = ⟨(0.35, 0.35, 0.10), (0.50, 0.75, 0.80), (0.50, 0.75, 0.65)⟩, Ñ2 = ⟨(0.40, 0.30, 0.35), (0.50, 0.45, 0.60), (0.45, 0.40, 0.60)⟩ be two T2NNs over the universe Z. Then, the Aczel-Alsina operations can be applied using Theorem 1 for ξ = 2 and ω = 3. Ñ1 ⊕ Ñ2 = Ñ2 ⊕ Ñ1 K. Kara et al. / Eur. J. Pure Appl. Math, 18 (4) (2025), 6753 6 of 20 ⇒ [ 1− e− ( (− ln(1−0.35))2+(− ln(1−0.40))2 )1/2 , 1− e− ( (− ln(1−0.35))2+(− ln(1−0.30))2 )1/2 , 1− e− ( (− ln(1−0.10))2+(− ln(1−0.35))δ )1/2 ; 1− e− ( (− ln(1−0.50))2+(− ln(1−0.50))2 )1/2 , 1− e− ( (− ln(1−0.75))2+(− ln(1−0.45))2 )1/2 , 1− e− ( (− ln(1−0.80))2+(− ln(1−0.60))2 )1/2 ; e− ( (− ln 0.50)2+(− ln 0.45)2 )1/2 , e− ( (− ln 0.75)2+(− ln 0.40)2 )1/2 , e− ( (− ln 0.65)2+(− ln 0.60)2 )1/2 ] = [ 1− e− ( (− ln(1−0.40))2+(− ln(1−0.35))2 )1/2 , 1− e− ( (− ln(1−0.30))2+(− ln(1−0.35))2 )1/2 , 1− e− ( (− ln(1−0.35))2+(− ln(1−0.10))δ )1/2 ; 1− e− ( (− ln(1−0.50))2+(− ln(1−0.50))2 )1/2 , 1− e− ( (− ln(1−0.45))2+(− ln(1−0.75))2 )1/2 , 1− e− ( (− ln(1−0.60))2+(− ln(1−0.80))2 )1/2 ; e− ( (− ln 0.45)2+(− ln 0.50)2 )1/2 , e− ( (− ln 0.40)2+(− ln 0.75)2 )1/2 , e− ( (− ln 0.60)2+(− ln 0.65)2 )1/2 ] Result: 〈(0.49,0.43,0.36),(0.62,0.78,0.84),(0.35,0.38,0.51)〉=〈(0.49,0.43,0.36),(0.62,0.78,0.84),(0.35,0.38,0.51)〉. Proof. [Proof for Ñ1 ⊗ Ñ2 = Ñ2 ⊗ Ñ1] [ e− ( (− ln 0.35)2+(− ln 0.40)2 )1/2 , e− ( (− ln 0.35)2+(− ln 0.30)2 )1/2 , e− ( (− ln 0.10)2+(− ln 0.35)2 )1/2 ; 1− e− ( (− ln(1−0.50))2+(− ln(1−0.50))2 )1/2 , 1− e− ( (− ln(1−0.75))2+(− ln(1−0.45))2 )1/2 , 1− e− ( (− ln(1−0.80))2+(− ln(1−0.60))2 )1/2 ; 1− e− ( (− ln(1−0.50))2+(− ln(1−0.45))2 )1/2 , 1− e− ( (− ln(1−0.75))2+(− ln(1−0.40))2 )1/2 , 1− e− ( (− ln(1−0.65))2+(− ln(1−0.60))2 )1/2 ] [ e− ( (− ln 0.40)2+(− ln 0.35)2 )1/2 , e− ( (− ln 0.30)2+(− ln 0.35)2 )1/2 , e− ( (− ln 0.35)2+(− ln 0.10)2 )1/2 ; 1− e− ( (− ln(1−0.50))2+(− ln(1−0.50))2 )1/2 , 1− e− ( (− ln(1−0.45))2+(− ln(1−0.75))2 )1/2 , 1− e− ( (− ln(1−0.60))2+(− ln(1−0.80))2 )1/2 ; 1− e− ( (− ln(1−0.45))2+(− ln(1−0.50))2 )1/2 , 1− e− ( (− ln(1−0.40))2+(− ln(1−0.75))2 )1/2 , 1− e− ( (− ln(1−0.60))2+(− ln(1−0.65))2 )1/2 ] Result: 〈(0.25,0.20,0.08),(0.62,0.78,0.84),(0.60,0.77,0.75)〉=〈(0.25,0.20,0.08),(0.62,0.78,0.84),(0.60,0.77,0.75)〉. Proof: The others proof is straightforward. 3. Hamy Mean-based Aczel-Alsina Operations of Type-2 Neutrosophic Number Sets 3.1. Type-2 neutrosophic numbers Aczel–Alsina Hamy Mean Oper- ator Within this sub-section, we introduce the T2NNAAHM operator, which is formulated in accordance with the operational principles delineated in Definition 2. Definition 3. HM operator is defined as Eq. (5) [30, 34]: HMτ (θ1, θ2, . . . , θn) = ∑ 1≤i1<··· G2 > G4 > G3. Conversely, employing the T2NNAAWHM operator, the ranking is consistent, with the order G1 > G2 > G4 > G3. Table 4: The score and accuracy values of alternatives. Alternatives T2NNAAHM Operator T2NNAAWHM Operator Score function Accuracy function Score function Accuracy function G1 0.7801 0.7284 0.7147 0.3931 G2 0.7673 0.6199 0.6923 0.2882 G3 0.7207 0.6309 0.6595 0.3076 G4 0.7430 0.7788 0.6977 0.4822 6. Comparative Analysis 6.1. Comparison of T2NNWA with the Novel Aggregation Operators During this investigation, we introduced novel aggregation operators based on Hamy Mean, namely T2NNAAHM and T2NNAAWHM, grounded in Aczel–Alsina t-norm and t-conorm operations. Following the validation of these proposed aggregation operators, we have demonstrated their practical application through the comprehensive study extracted from Abdel-Basset et al. [2]. Additionally, within the scope of this research, we compared these research findings with the T2NNWA operator findings. Upon a comprehensive comparison of the findings derived from this research with those of Abdel-Basset et al. [2], a remarkable alignment is evident. Specifically, for ξ = 1 and τ = 2, the aggregated T2NN values, score functions, and accuracy function values derived from both the T2NNAAHM and T2NNWA operators exhibit congruence. A noticeable implication arises when considering the results obtained from the application of T2NNAAWHM and T2NNWA. For ξ = 1 and τ = 2, the T2NNAAHM operator and the T2NNAAWHM operator assign the first alternative as the best one. For a comprehensive comparative analysis, Table 5 is presented, which shows an overview of the juxtaposition between T2NNWA, T2NNAAHM, and T2NNAAWHM for T2NNs. 6.2. Comparison of the Novel Aggregation Operators based on Parameter Variations The ξ parameter in the proposed T2NNAAHM and T2NNAAWHM operators yields varying outcomes under different variations. These variations are examined in terms of the robustness of the alternative rankings obtained K. Kara et al. / Eur. J. Pure Appl. Math, 18 (4) (2025), 6753 17 of 20 Table 5: Comparison of aggregation operators for T2NNs. Operator G1 G2 G3 G4 Alt. rank T2NNWA 0.7461 0.7223 0.6906 0.7201 G1 > G2 > G4 > G3 T2NNAAHM 0.7801 0.7673 0.7207 0.7430 G1 > G2 > G4 > G3 T2NNAAWHM 0.7147 0.6923 0.6595 0.6977 G1 > G4 > G2 > G3 by comparing the generated score functions. Score function values and alternative rankings for various ξ parameter variations in the case of T2NNAAHM are presented in Table 6. Table 6: Score functions under various ξ for T2NNAAHM. ξ G1 G2 G3 G4 Alt. rank 1 0.7801 0.7673 0.7208 0.7430 G1 > G2 > G4 > G3 2 0.7522 0.7307 0.6900 0.7214 G1 > G2 > G4 > G3 3 0.7434 0.7138 0.6743 0.7091 G1 > G2 > G4 > G3 10 0.7435 0.6843 0.6441 0.6925 G1 > G4 > G2 > G3 15 0.7472 0.6806 0.6406 0.6913 G1 > G4 > G2 > G3 25 0.7513 0.6781 0.6387 0.6909 G1 > G4 > G2 > G3 50 0.7548 0.6765 0.6380 0.6912 G1 > G4 > G2 > G3 75 0.7560 0.6760 0.6378 0.6914 G1 > G4 > G2 > G3 100 0.7566 0.6758 0.6377 0.6914 G1 > G4 > G2 > G3 150 0.7572 0.6755 0.6377 0.6915 G1 > G4 > G2 > G3 The score function values and alternative rankings for various ξ parameter variations in the case of T2NNAAWHM are displayed in Table 7. Table 7: Score functions under various ξ for T2NNAAWHM. ξ G1 G2 G3 G4 Alt. rank 1 0.7148 0.6924 0.6596 0.6977 G1 > G4 > G2 > G3 2 0.7136 0.6875 0.6541 0.6926 G1 > G4 > G2 > G3 3 0.7177 0.6836 0.6491 0.6895 G1 > G4 > G2 > G3 10 0.7381 0.6746 0.6361 0.6876 G1 > G4 > G2 > G3 15 0.7440 0.6740 0.6353 0.6882 G1 > G4 > G2 > G3 25 0.7495 0.6741 0.6356 0.6892 G1 > G4 > G2 > G3 50 0.7540 0.6745 0.6365 0.6904 G1 > G4 > G2 > G3 75 0.7554 0.6747 0.6368 0.6908 G1 > G4 > G2 > G3 100 0.7562 0.6748 0.6370 0.6910 G1 > G4 > G2 > G3 150 0.7569 0.6748 0.6372 0.6912 G1 > G4 > G2 > G3 Upon close examination of the alternative rankings, it is evident that the alternative ranking remains unchanged within the T2NNAAWHM operator. Conversely, within the T2NNAAHM operator, a shift between the second and third ranks occurs when ξ = 10. Nevertheless, it is noteworthy that the ranking of the top-performing alternatives remains consistent across all ξ values for all operators. 7. Implications The findings of this research have several important implications for theory and practice: K. Kara et al. / Eur. J. Pure Appl. Math, 18 (4) (2025), 6753 18 of 20 (i) Introduction of novel operators: Two aggregation operators, T2NNAAHM and T2NNAAWHM, were devel- oped for use with T2NNs, expanding the currently limited set of available operators. (ii) Flexibility in aggregation: The T2NNAAHM operator provides an unweighted aggregation mechanism, while the T2NNAAWHM operator enables weighted aggregation, thus broadening applicability across different decision-making contexts. (iii) Theoretical advancement: Both operators are grounded in Hamy Mean averaging, derived through Aczél– Alsina t-norm and t-conorm operations, with assumptions and proofs rigorously established. (iv) Comparative reliability: Results obtained from the proposed operators consistently aligned with those pro- duced by the existing T2NNWA operator, thereby confirming the robustness and stability of the proposed approach. utility: The proposed operators offer decision-makers alternative aggregation outcomes, allowing for multiple perspectives in decision-making rather than a single deterministic result. 8. Conclusions This study has advanced the field of MADM by introducing two novel aggregation operators for T2NNs: the T2NNAAHM and T2NNAAWHM. Unlike the existing literature, which only includes the T2NNWA operator, the proposed operators broaden the methodological toolkit by incorporating Hamy Mean-based aggregation founded on Aczel–Alsina t-norms and t-conorms. Their mathematical development has been comprehensively detailed, ensuring transparency of assumptions and proofs. Empirical analyses demonstrated that both operators consistently produced outcomes comparable to those ob- tained with the T2NNWA operator, including under parameter � variations. This stability underscores the robustness of the Aczel–Alsina-based Hamy Mean MADM model. The ability to perform both weighted and unweighted ag- gregation enhances the adaptability of the proposed methods in diverse decision-making contexts, making them particularly valuable when handling linguistic expressions and uncertain information. Looking forward, future research could extend this line of work by exploring additional aggregation operators for T2NNs and systematically comparing their performance with both the newly developed operators and existing benchmarks. Such comparative investigations will not only deepen the understanding of operator robustness but also provide practitioners with more reliable tools for complex decision-making scenarios. 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