1. Principal Researcher, K-water Research Institute, 1689 beon-gil 125, Yuseong-daero, Yuseong-gu, Daejeon 305-730, Republic of Korea; formerly, Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, CA 95616 (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, CA 95616.