1. Department of Optoelectronics and Communication Engineering; National Kaohsiung Normal University; No.62, Shenjhong Rd., Yanchao District Kaohsiung City 82446 Taiwan
2. Department of Information Engineering; I-Shou University; No.1, Sec. 1, Syuecheng Rd., Dashu District Kaohsiung City 84001 Taiwan
3. Department of Mathematics; National Kaohsiung Normal University; No.62, Shenjhong Rd., Yanchao District Kaohsiung City 82446 Taiwan