1. Environment and Process Division, Korea Institute of Science and Technology, P.O. Box 131 Cheongryang Seoul, 130-630 Korea (E-mail: escho1226@hotmail.com)
2. Environment and Process Division, Korea Institute of Science and Technology, P.O. Box 131 Cheongryang Seoul, 130-630 Korea (E-mail: khahn@kist.re.kr)
3. Department of Civil Engineering, Polytechnic University, 6 MetroTech Centre, Brooklyn, NY11201, USA (E-mail: amolof@poly.edu)