1. Department of Electrical and Information EngineeringSeoul National University of Science and Technology232 Gongneung‐ro, Nowon‐guSeoul139‐743Korea
2. ICT Convergence Research TeamMetropolitan Transportation Research CenterKorea Railroad Research Institute176, Cheldobangmulgwan‐roUiwang‐siGyeonggi‐do437‐757Korea
3. Department of Electrical and Information EngineeringConvergence Institute of Biomedical Engineering and BiomaterialsSeoul National University of Science and Technology232 Gongneung‐ro, Nowon‐guSeoul139‐743Korea