1. Professor of Hydraulic Structures; also Adjunct Professor, Concordia Univ., Dept. of Hydraulic Engineering Tsinghua Univ., Beijing, China 100084.
2. Former Research Assistant, Dept. of Hydraulic Engineering, Tsinghua Univ., Beijing, China 100084.
3. Professor, Dept. of Building, Civil and Environmental Engineering, Concordia Univ., Montreal PQ, Canada H3G 1M8.
4. Professor of Hydraulic Structures, Dept. of Hydraulic Engineering, Tsinghua Univ., Beijing, China 100084.