1. Postdoctoral Researcher, Dept. of Construction Management, Univ. of Washington, 120 Architecture Hall, Campus Box 351610, Seattle, WA 98195 (corresponding author).
2. Associate Professor, Dept. of Architectural Engineering, Univ. of Seoul, Seoul 02504, South Korea.
3. Professor, Dept. of Architectural Engineering, Univ. of Seoul, Seoul 02504, South Korea.