1. Ph.D. Student, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801; formerly, Master’s Student, Dept. of Architecture and Architectural Engineering, Seoul National Univ., 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
2. Professor, Dept. of Architecture and Architectural Engineering, Seoul National Univ., 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea (corresponding author).