1. Asst. Prof., School of Civ. and Environmental Engrg., Cornell Univ., Ithaca, N.Y.
2. Assoc. Prof., Dept. of Civ. Engrg., Massachusetts Inst. of Tech., Cambridge, Mass.
3. Principal Research Engr. and Lect., Dept. of Civ. Engrg., Massachusetts Inst. of Tech., Cambridge, Mass.