1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
2. Professor, Dept. of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea (corresponding author).
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of California, 760 Davis Hall, Berkeley, CA 94720-1710.