1. a Department of Informatics , Kansai University , 2-1-1 Ryozenji-cho, Takatsuki, Osaka, 569-1095, Japan
2. b Graduate School of Informatics , Kansai University , 2-1-1 Ryozenji-cho, Takatsuki, Osaka, 569-1095, Japan
3. c Civil Engineering Design Division , Kajima Corporation , Tokyo, Japan
4. d Department of Civil, Environmental and Architectural Engineering , University of Colorado, CB 428 , Boulder, CO, 80309-0428, USA