1. Bechtel Inc., San Francisco, Calif,; formerly, Grad. Student and Research Assoc., Dept. of Civ. Engrg., Princeton Univ., Princeton, N.J.
2. Asst. Prof., Dept. of Structural Engrg., Cornell Univ., Ithaca, N.Y.; formerly, Research Assoc. and Lect. Dept. of Civ. Engrg., Princeton Univ., Princeton, N.J.
3. Prof., Dept. of Civ. Engrg., Princeton Univ., Princeton, N.J.