1. Department of Information and Communication Engineering, Dongguk University, Seoul, South Korea
2. School of Information and Communications Technology, Robotics, and Mechanical Engineering and Research Center for Hyper-Connected Convergence Technology, Hankyong National University, Anseong, South Korea
3. Graduate School of Information, Yonsei University, Seoul, South Korea
4. College of Computer Science and Software Engineering, Shenzhen University, Shenzhen, China