1. Research Fellow, Dept. of Civil, Environmental, and Architectural Engineering, Korea Univ., Seoul, 136–701, Korea; formerly, Research Scientist, Dept. of Civil, Structural, and Environmental Engineering, Univ. at Buffalo—State Univ. of New York, Buffalo, NY 14260.
2. Clifford C. Furnas Professor of Structural Engineering, Dept. of Civil, Structural and Environmental Engineering, Univ. at Buffalo—State Univ. of New York, Buffalo, NY 14260 (corresponding author).