1. Professor and Chair, Dept. of Civil and Environmental Engineering, Cullen College of Engineering, Univ. of Houston, Cullen College of Engineering Bldg. 1, 4726 Calhoun Rd., Room N107, Houston, TX 77204-4003 (corresponding author).
2. Graduate Student, Dept. of Industrial Engineering, Univ. of Parma, Parco Area delle Scienze 181/A, I-43124 Parma, Italy.
3. Professor, Dept. of Industrial Engineering, Univ. of Parma, Parco Area delle Scienze 181/A, I-43124 Parma, Italy; Construction Technologies Institute, Italian National Research Council, Lombardia 49, I-20098 San Giuliano Milanese (Mi), Italy.