1. Assistant Professor, Dept. of Civil Engineering, Univ. of Minnesota, Minneapolis, MN 55455-0233. E-mail: tokazaki@umn.edu
2. Professor, Dept. of Civil Engineering, The Univ. of Texas at Austin, Austin, TX 78712-0275.
3. Professor, Disaster Prevention Research Institute, Kyoto Univ., Gokasho, Uji, Kyoto 611-0011, Japan.
4. Associate Professor, Disaster Prevention Research Institute, Kyoto Univ., Gokasho, Uji, Kyoto 611-0011, Japan.