1. Center for Regional Environ. Research, National Inst. for Environ. Studies, Tsukuba, Ibaraki, Japan
2. Department of Civil Engineering and Architecture, National Institute of Technology, Tokuyama College, Gakuendai, Shuunan, Yamaguchi, Japan
3. Department of Civil Engineering, National Institute of Technology, Gifu, Motosu, Japan
4. Faculty of Applied Life Sciences, Niigata Univ. of Pharmacy and Applied Life Sciences, Niigata, Japan