1. Yi-Hsien Chiang, Taiwan R&D Center, Nidec Corporation, No. 37, Gongye 2nd Rd., Annan Dist; Tainan 70955 Taiwan
2. Department of Environmental Engineering; Chung Yuan Christian University; Chung-Li 32023 Taiwan
3. Department of Mechanical Engineering; National Chin-Yi University of Technology; Taichung 41170 Taiwan