1. Formerly, Dept. of Civil Engineering and Geological Sciences, Univ. of Notre Dame, Notre Dame, IN 46556.
2. Engineer, AIR Worldwide, 131 Dartmouth St., Boston, MA 02116 (corresponding author).
3. Robert M. Moran Professor, Dept. of Civil Engineering and Geological Sciences, Univ. of Notre Dame, Notre Dame, IN 46556.
4. Distinguished Professor, Dept. of Applied Mathematics and Statistics, State Univ. of New York, Stony Brook, NY 11794-3600.
5. Engineer, Energy Technology Division, Argonne National Laboratory, 9700 South Cass Ave., Argonne, IL 60439.