1. Department of IT-Energy Convergence (BK21 FOUR), Korea National University of Transportation, 50 Daehak-ro, Chungju-si 27469, Republic of Korea
2. Department of Electronics Engineering, Korea National University of Transportation, 50 Daehak-ro, Chungju-si 27469, Republic of Korea
3. Department of Smart Information and Telecommunication Engineering, Sangmyung University, 31, Sangmyeongdae-gil, Dongnam-gu, Cheonan-si 31066, Republic of Korea