1. Department of Railroad Operation Systems Engineering, Korea National University of Transportation, Uiwang-si 16106, Republic of Korea
2. Railroad Safety Division, Korea Railroad Research Institute, Uiwang-si 16105, Republic of Korea
3. Department of Automotive Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
4. School of Mechanical Engineering, Sungkyunkwan University, Seoul 06351, Republic of Korea