1. Postdoctoral Research Associate, Engineering Research Institute, Ajou Univ., Suwon 443-749, South Korea.
2. Associate Professor, Dept. of Architecture, Ajou Univ., Suwon 443-749, South Korea (corresponding author).
3. Associate Professor, College of Architecture, Myongji Univ., Yongin 449-728, South Korea.
4. Associate Professor, Dept. of Architectural Engineering, Sungkyunkwan Univ., Suwon 400-746, South Korea.