1. Staff Engineer, Hansen, Allen, and Luce, Inc., 6771 South 900 East, Midvale, UT 84047 (corresponding author).
2. Professor, Utah State Univ., 8200 Old Main Hill, Logan, UT 84322-8200.
3. Research Assistant Professor, Utah State Univ., 8200 Old Main Hill, Logan, UT 84322-8200. E-mail: steve.barfuss@.usu.edu