1. Graduate Student, Dept. of Civil and Environmental Engineering, Louisiana State Univ., 3526B Patrick F. Taylor Hall, Baton Rouge, LA 70803.
2. Professor, Dept. of Civil and Environmental Engineering, Louisiana State Univ., 3526B Patrick F. Taylor Hall, Baton Rouge, LA 70803 (corresponding author).
3. Professor, Dept. of Agricultural Economics and Agribusiness, Louisiana State Univ., and LSU Agricultural Center, Baton Rouge, LA 70803.