1. Visiting Professor, Dept. of Civil and Environmental Engineering, Univ. of Cincinnati, 765 Baldwin Hall, P.O. Box 210071, Cincinnati, OH 45221-0071.
2. Full Professor, School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Dr., Atlanta, GA 30303.
3. Associate Professor, Dept. of Civil Engineering, Univ. of Trieste, Via A. Valerio 6/1, 34127 Trieste, Italy.