1. Professor, Civil Engineering Dept., Clemson Univ., Clemson, SC 29634-0911.
2. Research Assistant, Civil Engineering Dept., Clemson Univ., Clemson, SC 29634-0911.
3. Professor, Civil Engineering Dept., National Cheng Kung Univ., Tainan, Taiwan.
4. Professor, Civil Engineering Dept., National Chung Hsing Univ., Taichung, Taiwan.