1. Ph.D. Candidate, Division of Engineering and Policy for Sustainable Environment, Graduate School of Engineering, Hokkaido Univ., Kita 13 Jo Nishi 8 Chome Kita-ku, Sapporo 060-8628, Japan.
2. Professor, Division of Engineering and Policy for Sustainable Environment, Faculty of Engineering, Hokkaido Univ., Kita 13 Jo Nishi 8 Chome Kita-ku, Sapporo 060-8628, Japan.
3. Associate Professor, Dept. of Civil Engineering, College of Civil Engineering and Architecture, Zhejiang Univ., Hangzhou 310058, China (corresponding author).