1. Associate Professor, Faculty of Environmental and Urban Engineering, Kansai Univ., 3-3-35 Yamatecho, Suita, Osaka 564-8680, Japan; formerly, Assistant Professor, Faculty of Software and Information Science, Iwate Prefectural Univ., 152-52 Sugo, Takizawa, Iwate 020-0193, Japan (corresponding author).
2. Professor Emeritus, Faculty of Environmental and Urban Engineering, Kansai Univ., 3-3-35 Yamatecho, Suita, Osaka 564-8680, Japan.