1. Lecturer, Civil Engineering, College of Engineering and Mathematical Sciences, Univ. of Vermont, 33 Colchester Ave., 377 Votey, Burlington, VT 05405 (corresponding author).
2. Graduate Research Assistant, School of Aerospace and Mechanical Engineering, Univ. of Oklahoma, 865 Asp Ave., Felgar Hall, 212, Norman, OK 73019-1052.
3. Professor, School of Civil Engineering and Environmental Science, Univ. of Oklahoma, 202 W. Boyd St., Carson Engineering Center, Room 334, Norman, OK 73019-1024.
4. Associate Professor, School of Aerospace and Mechanical Engineering, Univ. of Oklahoma, 865 Asp Ave., Felgar Hall, Room 209A, Norman, OK 73019-1052.