1. Professor, Dept. of International Development Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
2. Lecturer, Dept. of Civil Engineering, Kanazawa Institute of Technology, 7-1 O-ogigaoka, Nonoichi-machi, Ishikawa-gun, Ishikawa-ken, 921-8501, Japan.
3. Graduate Student, Dept. of International Development Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552, Japan.