1. Assistant Professor, Dept. of Civil Engineering, Univ. of Southern California, Los Angeles, CA 90089 (corresponding author).
2. Lecturer, Dept. Building and Construction, City Univ. of Hong Kong, Tat Chee Ave., Kowloon, Hong Kong.
3. Associate Professor, Dept. Civil Engineering, Hong Kong Univ. of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
4. Professor, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125.