1. Postdoctoral Researcher, Univ. of Illinois Urbana-Champaign, 1325 Richelieu Ln., Houston, TX 77018 (corresponding author).
2. Associate Professor, Univ. of Chile, Beauchef 850, Santiago, Chile.
3. Professor and Associate Head, Dept. of Civil and Environmental Engineering, Univ. of Illinois Urbana-Champaign, 3129B Newmark Civil Engineering Building, 205 N Mathews Ave., Urbana, IL 61801.
4. Professor, Dept. of Civil and Environmental Engineering, Univ. of Washington, 214 B More Hall, P.O. Box 352700, Seattle, WA 98125.
5. Earthquake Engineering Group Leader, Materials and Structural Systems Division, Engineering Laboratory, Gaithersburg, MD.
6. Graduate Researcher, Univ. of Chile, Beauchef 850, Santiago, Chile.