1. Prof. of Civ. Engrg. and Mechanics, Drexel Inst. of Tech., Philadelphia, Pa
2. Assoc. Prof. of Civ. Engrg. and Mechanics, Drexel Inst. of Tech., Philadelphia, Pa
3. Research Asst., Dept. of Civ. Engrg. and Mechanics, Drexel Inst. of Tech., Philadelphia, Pa