1. Mathes Professor, Dept. of Civil Engineering, Univ. of Missouri-Rolla, 202 Civil Engineering Building, Rolla, MO 65409.
2. Graduate Research Assistant, Univ. of Missouri-Rolla, 202 Civil Engineering Building, Rolla, MO 65409.
3. Senior Research Scientist, United States Geological Survey, 4500 SW 40th Ave., Ocala, FL 34474.