1. State Key Joint Laboratory of Environment Simulation and Pollution Control
2. School of Environment
3. Tsinghua University
4. Beijing 100084
5. China
6. Beijing Municipal Engineering Design and Research Institute
7. Beijing
8. Center for Statistical Science and Department of Industrial Engineering
9. Dept. of Civil and Environmental Engineering
10. Univ. of Alberta
11. Edmonton
12. T6G 2W2 Canada