1. Postdoctoral Fellow, Dept. of Civil Engineering, Johns Hopkins Univ., Baltimore, MD 21218 (corresponding author).
2. Professor, Dept. of Civil Engineering, Florida Institute of Technology, Melbourne, FL 32901.
3. Associate Professor, Dept. of Civil and Coastal Engineering, Univ. of Florida, Gainesville, FL 32611.
4. Assistant Professor, Dept. of Civil Engineering and Emergency Medicine, Johns Hopkins Univ., Baltimore, MD 21218.