1. Assistant Professor, Dept. of Civil, Architectural and Environmental Engineering, Univ. of Texas at Austin, Austin, TX 78712 (corresponding author).
2. Professor, School of Civil Engineering, Purdue Univ., West Lafayette, IN 47907.
3. Associate Professor, School of Civil Engineering, Purdue Univ., West Lafayette, IN 47907.
4. Professor Emeritus, School of Civil Engineering, Purdue Univ., West Lafayette, IN 47907.
5. Professor, Dept. of Agronomy, Purdue Univ., West Lafayette, IN 47907.