1. Associate Professor, Dept. of Structural Engineering, Univ. of California, San Diego, La Jolla, CA 92093-0085.
2. Postgraduate Researcher, Dept. of Structural Engineering, Univ. of California, San Diego, La Jolla, CA 92093-0085.
3. Division Head, Structural Dynamics Division, Port and Airport Research Institute, Yokosuka-shi, Kanagawa 239-0826, Japan.
4. Professor, Dept. of Civil Engineering, Waseda Univ., Ookubo, Shinjuku-Ku, Tokyo, Japan.