1. a Department of Aeronautical Engineering, National Formosa University, 64, Wenhua Road, Huwei, Yunlin 632, Taiwan, R.O.C.
2. b Department of Electronic Engineering, Nan-Kai University of Technology, 568, Chung-cheng Road, Caotun, Nantou 542, Taiwan, R.O.C.
3. c Department of Aeronautical Engineering, National Formosa University, 64, Wenhua Road, Huwei, Yunlin 632, Taiwan, R.O.C.