1. Sr. Engr., Tetra Tech, Inc., Pasadena, Calif. 91107. Formerly Grad. Research Asst., Dept. of Civ. Engrg., Univ. of Southern California, Los Angeles, Calif. 90007
2. Assoc. Prof. of Civ. Engrg., Univ of Southern California, Los Angeles, Calif. 90007