1. Associate Professor, Dept. of Civil Engineering, National Univ. of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Central Florida, 4000 Central Florida Blvd., P.O. Box 162450, Orlando, FL 32816-2450.
3. Assistant Professor, Dept. of Civil Engineering, National Univ. of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
4. Professor, Dept. of Civil Engineering, National Univ. of Singapore., 10 Kent Ridge Crescent, Singapore 119260.