1. Associate Professor, Dept. of Environmental and Urban Systems Engineering, Ajou Univ., San 5 Wonchon-dong, Paldal-gu, Suwon, Korea.
2. Professor, Dept. of Civil Engineering, Texas A&M Univ., R 304C, CE/TTI Tower, College Station, TX 77843-3135.
3. Professor, Dept. of Environmental and Urban Systems Engineering, Ajou Univ., San 5 Wonchon-dong, Paldal-gu, Suwon, Korea.