1. Assistant Professor, Dept. of Civil and Environmental Engineering, Princeton Univ., E-Quad E-328, Princeton, NJ 08544.
2. Bruce G. Johnston Professor of Structural Engineering, Dept. of Civil and Environmental Engineering, ATLSS Center Faculty Associate, Lehigh Univ., 117 ATLSS Drive, Building H, Bethlehem PA 18015.
3. Joseph T. Stuart Professor, Dept. of Civil and Environmental Engineering, ATLSS Center Director, Lehigh Univ., 117 ATLSS Drive, Building H, Bethlehem PA 18015.