1. Prof., Div. of Struct. Engrg., Univ. of California, San Diego, 9500 Gilman Drive, Mail Code 0085, La Jolla, CA 92093.
2. Assoc. Prof. of Struct. Engrg., EPICENTRE Res. Group, Ecole Polytechnique, Univ. of Montreal Campus, P.O. Box 6079, Station “Centre-Ville,” Montreal, PQ, Canada H3C 3A7.
3. Prin., Spectrum Engineering Inc., 307-1199 Eastwood St., Coquitlam, BC, Canada V3B 7W7.