1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of Michigan, 2350 Hayward St., Room 1006, G.G. Brown Bldg., Ann Arbor, MI 48109.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, 2350 Hayward St., Room 2140, G.G. Brown Bldg., Ann Arbor, MI 48109.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, 2350 Hayward St., Room 2140, G.G. Brown Bldg., Ann Arbor, MI 48109.