1. Associate Professor, School of Management Science and Engineering, Central Univ. of Finance and Economics, Beijing 100081, China.
2. Professor, School of Management Science and Engineering, Central Univ. of Finance and Economics, Beijing 100081, China.
3. Professor, College of Engineering, Dept. of Construction Management, Louisiana State Univ., Baton Rouge, LA 70803 (corresponding author).
4. Associate Professor, Dept. of Construction Management, School of Civil Engineering, Tsinghua Univ., Beijing 100084, China.