1. Ph.D. Candidate, Dept. of Architecture, School of Engineering, Univ. of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan (corresponding author).
2. Professor, Dept. of Architecture, School of Engineering, Univ. of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.