1. Postdoctoral Fellow, School of Civil and Environmental Engineering, Nanyang Technological Univ., 50 Nanyang Ave. Singapore 639798.
2. Assistant Professor, Dept. of Civil Engineering, Technical Univ. of Gdansk, Ul. Narutowicza 11/12, 80-952 Gdansk, Poland.
3. Professor, Dept. of Civil Engineering, Univ. of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan.