1. a Metal Industries Research & Development Center, 3F, No. 88, Luke 5th Rd., Lujhu Township, Kaoshiung, Taiwan 82151, Taiwan
2. b Department of Electrical Engineering, National University of Tainan, 33, Sec. 2, Shu-Lin St., Tainan 700, Taiwan;, Email: cyhun@mail.nutn.edu.tw
3. c Department of Material Engineering, National Pingtung University of Science and Technology, No. 1, Syuefu Rd., Neipu Township, Pingtung County 912, Taiwan
4. d Department of Electronics Engineering and Computer Sciences, Tung-Fang Institute of Technology, No. 110, Tung-Fung Road, Hunei Shiang, Kaohsiung County 829, Taiwan