1. Ph.D. Student, Dept. of Urban Management, Graduate School of Engineering, Kyoto Univ., Kyoto 615-8540, Japan (corresponding author).
2. Professor, Dept. of Urban Management, Graduate School of Engineering, Kyoto Univ., Kyoto 615-8540, Japan.
3. Professor, Graduate School of Engineering, Nagasaki Univ., Nagasaki 852-8521, Japan.