1. Ph.D. Student, Dept. of Civil and Environmental Engineering, Stanford Univ., 473 Via Ortega, Stanford, CA 94305-4020.
2. Project Engineer, Larson Design Group, 1 West Market St., Corning, NY 14830.
3. Associate Professor, Dept. of Civil and Environmental Engineering, Pennsylvania State Univ., 212 Sackett Building, University Park, PA 16802-1408 (corresponding author).