1. Assistant Professor, Dept. of Civil Engineering and Construction Engineering Management, California State Univ., Long Beach, CA 90840 (corresponding author).
2. Assistant Professor, Dept. of Civil and Construction Engineering, National Taiwan Univ. of Science and Technology, Taipei, Taiwan 10607, Republic of China.
3. Assistant Professor, Dept. of Civil Engineering, Hongik Univ., Seoul, South Korea.
4. Professor, Dept. of Civil and Environmental Engineering, Northwestern Univ., Evanston, IL 60208.