1. 1Graduate School of Transportation, Korea National University of Transportation, Uiwang 437-763, Republic of Korea, and Department of IT Convergence, Korea National University of Transportation, Chungju 380-702, Republic of Korea
2. Department of Software Engineering, Korea National University of Transportation, Chungju 380-702, Republic of Korea
3. Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380-702, Republic of Korea
4. Department of Electronic Engineering, Semyung University, Jecheon 390-711, Republic of Korea