1. Department of Civil Engineering, University of Inchon, 177 Dowha-2Dong, Nam-Gu, Inchon, South Korea, 402-749, Telephone: 82/32-770-8466, Telefax: 82/32-770-8460,
2. College of Engineering and Computer Science, California State University, Sacramento, California, 95819-6023, Telephone: 1/916-278-6127, Telefax: 1/916-278-5949,