1. BK Research Assistant Professor, Dept. of Constructional and Environmental System Engineering, Sungkyunkwan Univ., Korea; formerly, Ph.D. Graduate Student and Professional Research Assistant, Dept. of Civil Engineering, Univ. of Colorado at Denver, Campus Box 113, Denver, CO 80217-3364.
2. Professor, Dept. of Civil Engineering, Univ. of Colorado at Denver, Campus Box 113, Denver, CO 80217-3364 (corresponding author).