1. Postdoctoral Research Associate, Dept. of Civil and Environmental Engineering, Univ. of California, Davis, CA 95616; presently at School of Civil and Environmental Engineering, Cornell Univ., Ithaca, NY 14853.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of California. Davis, CA 95616.
3. Professor, Dept. of Civil and Environmental Engineering, Stanford Univ., Stanford, CA 94305-4020.
4. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of California. Berkeley, CA 94720-1710.