1. Ph.D. Candidate, Dept. of Civil Engineering, Auburn Univ., 238 Harbert Engineering Center, Auburn, AL 36849-5337. E-mail: yitaewo@auburn.edu
2. Assistant Professor, Dept. of Civil Engineering, Auburn Univ., 238 Harbert Engineering Center, Auburn, AL 36849-5337 (corresponding author). E-mail: wharper@eng.auburn.edu
3. Research Scientist, National Institute of Standards and Technology, 100 Bureau Dr., Stop 8371 Gaithersburg, MD 20899. E-mail: dave.holbrook@nist.gov
4. Professor, Civil and Environmental Engineering, Virginia Tech, 403 Durham Hall, Blackburg, VA 24061. E-mail: nlove@vt.edu