1. Structural Engineer, Simpson Gumpertz & Heger, 4695 MacArthur Ct. #500, Newport Beach, CA 92660; formerly, Ph.D. Graduate, Univ. of California, Irvine, 4135 Engineering Gateway, Irvine, CA 92697.
2. Professor, Dept. of Civil Engineering, Univ. of California, Los Angeles, 5731 Boelter Hall, Los Angeles, CA 90095.
3. Assistant Professor, Dept. of Civil Engineering, Univ. of California, Irvine, 4135 Engineering Gateway, Irvine, CA 92697 (corresponding author).