1. Department of Electrical Engineering, National Sun Yat-sen University, No. 70 Lienhai Road, Kaohsiung 80424, Taiwan
2. Department of Electronic Engineering, De Lin Institute of Technology, Lane 380, No. 1 Qingyun Road, Tucheng District, New Taipei 23654, Taiwan
3. Department of Computer and Communication, Shu-Te University, No. 59 Hengshan Road, Yanchao District, Kaohsiung 82445, Taiwan