1. Deputy Director, Multidisciplinary Center for Earthquake Engineering Research and Professor, Dept. of Civil, Structural and Environmental Engineering, State Univ. of New York, Buffalo, New York 14260; formerly, Professor, Dept. of Structural Engineering, Univ. of California at San Diego, La Jolla, CA 92093 (corresponding author).
2. Graduate Research Student, Dept. of Structural Engineering, Univ. of California at San Diego, La Jolla, CA 92093.