1. Lecturer, Advanced Research Laboratories, Tokyo City Univ., 8-15-1 Todoroki, Setagaya 158-0082, Japan (corresponding author).
2. Chief Officer for Structure Maintenance Management, Kanto Engineering Laboratory, Ministry of Land, Infrastructure, Transport and Tourism, 6-12-1 Goko Nishi, Matsudo City, Chiba Prefecture 270-2218, Japan.
3. President, Tokyo City Univ., 1-28-1 Tamazutsumi, Setagaya, 158-8557, Japan.