1. Department of Civil and Coastal Engineering, University of Florida, 365 Weil Hall, Box 116580, Gainesville, FL 32611.
2. Department of Industrial Engineering, Tsinghua University, N502 Shunde Building, Beijing 100084, China.
3. Department of Civil and Material Engineering, University of Illinois at Chicago, 2089 ERF, 842 West Taylor Street, Chicago, IL 60607.