1. Researcher, Earthquake Research Institute, Univ. of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan (corresponding author).
2. Professor, Dept. of Architecture, Hokkaido Univ., Sapporo 060-8628, Japan.
3. Associate Professor, Earthquake Research Institute, Univ. of Tokyo, Tokyo, Japan.
4. Professor, Dept. of Architecture, Osaka Univ., Osaka 113-0032, Japan.
5. Professor, Research Institute for Sustainable Humanosphere, Kyoto Univ., Uji 611-0011, Japan.