1. Ph.D. Candidate, Dept. of Civil and Architectural Engineering, City Univ. of Hong Kong, Tat Chee Ave., Kowloon, Hong Kong 999077, P.R. China.
2. Professor, Dept. of Civil and Architectural Engineering, City Univ. of Hong Kong, Tat Chee Ave., Kowloon, Hong Kong 999077, P.R. China (corresponding author).
3. Postdoctoral Fellow, Dept. of Systems Engineering and Engineering Management, City Univ. of Hong Kong, Tat Chee Ave., Kowloon, Hong Kong 999077, P.R. China.