1. Assistant Professor, Dept. of Environmental Engineering and Management, Chaoyang Univ. of Technology, Wufeng, Taichung, 413, Taiwan.
2. Associate Professor, Dept. of Civil Engineering, National Chi Nan Univ., PuLi, Nantou, 545, Taiwan.
3. Professor, Graduate Institute of Environmental Engineering, National Central Univ., Chungli, 32054, Taiwan.