1. Associate Professor, Valparaiso Univ., Valparaiso, IN 46383. E-mail: carmine.polito@valpo.edu
2. Associate Professor, Dept. of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061. E-mail: rugreen@vt.edu
3. Doctoral Candidate, Dept. of Civil and Environmental Engineering, Univ. of Michigan, Ann Arbor, MI 48109.