1. Transportation & ICT Convergence Research Center, Korea National University of Transportation (KNUT), 50 Deahak-ro, Chungju-si 27469, Chungcheongbuk-do, Republic of Korea
2. Graduate School of Business Administration, Kobe University, 2-1 Rokkodaicho, Nada, Kobe 657-0013, Hyogo, Japan
3. Korea Railroad Research Institute (KRRI), 176, Cheoldobangmulgwan-ro (Woram-dong), Uiwang-si 16105, Gyeonggi-do, Republic of Korea