1. Department of Mechanical Engineering, Ching-Yun Institute of Technology, Chung-Li, Taiwan 32020, R.O.C.
2. Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan 70101, R.O.C.
3. Department of Electrical and Electronics Engineering, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, Wales, U.K.
4. Department of Electronic Engineering, Chung Yuan University, Chung-Li, Taiwan 32023, R.O.C.