1. Department of Urban and Environmental Engineering, Kyoto University , Yoshida Hon-machi, Sakyo-ku, Kyoto 606-8501, Japan
2. School of Urban and Environmental Engineering, Kyoto University , Yoshida Hon-machi, Sakyo-ku, Kyoto 606-8501, Japan
3. Technical Research Center, The Kansai Electric Power Company Incorporation , Hyogo, 561-0974, Japan