1. Postdoctoral Fellow, Center for Environmental Restoration and Disaster Reduction, National Chung-Hsing University, Taichung, Taiwan 40227, R.O.C. E-mail: kai@dragon.nchu.edu.tw
2. Associate Professor, Department of Civil and Environmental Engineering, Utah State University, Logan, Utah 84322. E-mail: halling@cc.usu.edu
3. Assistant Professor, Department of Civil and Environmental Engineering, Utah State University, Logan, Utah 84322. E-mail: pbarr@cc.usu.edu