1. Postdoctoral Researcher, Dept. of Structural Engineering, Tongji Univ., Shanghai 20092, China; formerly, Ph.D. Student, Dept. of Civil and Environmental Engineering, Univ. of California, Los Angeles, CA 90095.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Los Angeles, CA 90095 (corresponding author).
3. Professor, Dept. of Civil, Environmental Engineering, and Mechanical Engineering, Rice Univ., Houston, TX 77005.