1. a Department of Electronics Engineering and Computer Sciences, Tung-Fang Design University, No. 110, Tung-Fung Road, Hunei Shiang, Kaohsiung 829, Taiwan
2. b Medical Devices and Opto-electronics Equipment Department, Metal Industries Research & Development Center, 3F, No. 88, Luke 5th Rd., Lujhu Township, Kaohsiung 82151, Taiwan
3. c Department of Electrical Engineering, National University of Tainan, No. 33, Sec. 2, Shu-Lin Street, Tainan 700, Taiwan
4. d Department of Electrical Engineering, National University of Tainan, No. 33, Sec. 2, Shu-Lin Street, Tainan 700, Taiwan;, Email: cyhun@ieee.org