1. Visiting Assistant Professor, Dept. of Civil Engineering, Indian Institute of Technology Madras, Chennai 600 036, India (corresponding author).
2. Snead Chair Professor, Dept. of Civil Engineering and Texas Transportation Institute, Texas A&M Univ., 3135 TAMU, College Station, TX 77843-3135.
3. University Distinguished Professor and Forsyth Chair Professor, Dept. of Mechanical Engineering, Texas A&M Univ., 3135 TAMU, College Station, TX 77843-3135.