1. Assistant Professor, Dept. of Construction Engineering, National Taiwan Univ. of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan (corresponding author). E-mail: hungming@mail.ntust.edu.tw
2. Ph.D. student, Dept. of Construction Engineering, National Taiwan Univ. of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan.
3. Graduate Student, Dept. of Construction Engineering, National Taiwan Univ. of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan.