 Proceedings of Engineering and Technology Innovation , vol. 2, 2016, pp. 04 - 05 4 A Low-cost Design of Earthquake Detector with Rescue Message Deliver using Mobile Device Chuen-Ching Wang * , Gi-Hong Wei Department of Information Technology, Kao Yuan University, Kaohsiung, Taiwan. Received 30 January 2016; received in revised form 15 February 2016; accept ed 18 March 2016 Abstract The earthquake detector is a complex and ex- pensive device. It is necessary to design a simpler and cheaper earthquake detector for common use. Our research employs the ability of Android-based mobile device to design a minima l cost detector for sensing the earthquake. Therefore, as the earth- quake occurring, the mobile device can detect the earthquake and issue a warning alarm to the phone owner. At the same time, a rescue messages in- cluding disaster location, earthquake level, and related information to the disaster center. Experi- mental results show that the proposed method can achieve the usage of disaster rescue. Keywor ds : earthquake detection, earthquake early warn ing system, ce ll broadcast service 1. Introduction Because earthquake occurrence is difficult to predict, the earthquake hazard plays a major role in the natural disaster. For seismic hazard mitigation, a practical earthquake forecast method appears to be far from realization, because of the extreme complexity involved in the earthquake processes. There are two types of seismic waves:[1-2]body waves that propagate through the earth’s interior and surface waves that propagate along the earth’s free surface or along other discontinuities in the earth’s interior. Body waves traveling faster than the surface waves are classified to two types: compressional (longitudinal) and shear (transverse). Compressional waves travel about 1.7 times faster than transverse waves and are often called P waves or primary waves. Transverse waves are frequently called S waves or secondary waves. P waves are always the first among seismic waves that reach the recording station. Rock particles affected by a propagating P wave oscillate backward and fo r- ward in the same direction as the wave propagates. In the case of S waves, particles vibrate in planes perpendicular to the direction of travel [3]. In this investigation, an earthquake detector is designed using the accelerator which e xists in the mob ile device to immediate ly ca lculate a c - celeration, and therefore the earthquake amp li- tude can be detected. 2. Earthquake Detection Design Due to the rapid development of mobile communicat ions, mob ile devices currently can provide anyone, anywhere, and any when to access the Internet through the communication network. For the reason of mobility, we imple - ment the proposed method in the mobile device to reduce the cost of earthquake detector. We e xpress the main process shown as follows. First, when earthquake is occurring, the earthquake signal will be detected by G-sensor, which can sense the acceleration and orientation. Ne xt , the acceleration is calcu lated by the co mputation module and transferred as earthquake magnitude. The earthquake magnitude can be used for de- termin ing whether an alarm/ message is issued, or not. That is, if the earthquake magnitude is greater than the specific threshold, then the lo- cation information (Lat itude and longitude) is obtained by GPS wh ich built in mobile device and thus the location information can be passed to the alarm module to issue alarm and rescue messages to notify the specific person or disaster center. In order to obtain the s ma llest possible errors, the phone accelerometer is compared with a standard accelerometer located at the National Center for Research on Ea rthquake Engineering (NCREE) [4]. Fig. 1 shows our tes t phone (marked with red bo x) is set on the accelerom- eter calibration system. The process is shown as follows : * Corresponding aut hor. Email: t 90261@cc.kyu.edu.tw Proceedings of Engineering and Technology Innovation , vol. 2, 2016, pp. 04 - 05 5 Copyright © TAETI (1) Set the phone on the fixed standard accel- erometer (2) Adjust the device parameters (3) Repeat step 1 and 2 until the phone output a reasonable range. Fig. 1 Comparison of the accelerator in mobile device and standard accelerometer at NCREE 3. Conclusions We have integrated the gravity accelerome - ter, GPS module and co mmunication modules and other hardware system to imp le ment an earthquake detection APP in the mobile device. De monstrations show that the APP can detect the earthquake intensity, latitude and longitude informat ion, time of occurrence, phone number and other messages and forward these infor- mat ion to the specified relat ives or disaster center using mobile commun ication. The pro- posed scheme with advantages of easy installing and no extra hardware cost. Acknowledgment The research is supported by the NSC 104-2221-E-244-018-, National Science Council, Taiwan. Reference [1] “Central Weather Bureau,” http://www.cwb.gov.tw/ [2] S. L. Kra mer, Geotechnical Ea rthquake Engineering, NJ: Prentice-Hall, Engelwood Cliffs, 2003. [3] A. Magro-Ca mpe ro, R. L. Fle ischer, and R. S. Likes, “ Changes in subsurface radon concentration associated with earthquakes,” J. Geophys. Res., vol. 85, no. B6, pp. 3053-3057, 1980. [4] “National Center for Research on Eart h- quake Engineering,” http://www.ncree.org/