1. Professor, Dept. of Construction Management, School of Civil Engineering, Tsinghua Univ., Beijing, China 100084.
2. PhD Student and Graduate Research Assistant, Dept. of Civil Engineering, Univ. of British Columbia, Vancouver BC, Canada V6T 1z4; formerly, Master Student, Dept. of Construction Management, School of Civil Engineering, Tsinghua Univ., Beijing, China 100084.
3. Associate Professor, Dept. of Building & Real Estate, Hong Kong Polytechnic Univ., Hung Hom, Kowloon, Hong Kong.
4. Professor, Dept. of Building & Real Estate, Hong Kong Polytechinc Univ., Hung Hom, Kowloon, Hong Kong.