1. Lecturer, Dept. of Civil and Environmental Engineering, Mahidol Univ., Nakhon Pathom 73170, Thailand; formerly, Graduate Assistant, School of Civil and Construction Engineering, Oregon State Univ., Corvallis, OR 97331 (corresponding author).
2. Deceased August 18, 2010; formerly, Associate Professor, School of Civil and Construction Engineering, Oregon State Univ., Corvallis, OR 97331.
3. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Delaware, Newark, DE 19716.