1. Associate Professor, Dept. of Civil Engineering, Shihezi Univ., Shihezi, Xinjiang 832003, P.R. China.
2. Professor, Dept. of Water Resources Engineering, Lund Univ., Box 118, S-22100 Lund, Sweden.
3. A. K. Barton Professor, Dept. of Civil & Environmental Engineering, Louisiana State Univ., Baton Rouge, LA 70803-6405.
4. Rubicon Professor, Dept. of Civil & Environmental Engineering, Louisiana State Univ., Baton Rouge, LA 70803-6405.