1. Associate Professor, Dept. of Architecture, Seoul National Univ., San 56-1, Shinlim-Dong, Kwanak-Gu, Seoul 151-742, South Korea. E-mail: parkhg@snu.ac.kr
2. Graduate Student, Dept. of Architecture, Seoul National Univ., San 56-1, Shinlim-Dong, Kwanak-Gu, Seoul 151-742, South Korea.
3. Researcher, Steel Structure Technology Division, Research Institute of Industrial Science and Technology (RIST), 79-5, Youngcheon, Dongtan, Hwasung, Kyungkido 445-810, South Korea.
4. Professor, Dept. of Architectural Engineering, Hoseo Univ., San 29-1, Saechul-ri, Baebang-Myun, Asan, Choongnam 336-795, South Korea.