1. Department of Mechanical, Robotics and Energy Engineering, Dongguk University, Jung-gu, Seoul 04620, Republic of Korea
2. Quantum Functional Semiconductor Research Center, Dongguk University, Jung-gu, Seoul 04620, Republic of Korea
3. Development of SMART Community Policing System (Googi) Research Center, Dongguk University, Jung-gu, Seoul 04620, Republic of Korea