1. Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
2. Department of Electrical Engineering, Yuan Ze University, Chung-Li, 32003, Taiwan
3. College of Mathematics and Systems, Shandong University of Science and Technology, Qingdao 266590, China
4. College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, China
5. School of Mathematics and Computational Science, Sun Yat-Sen University, Guangzhou 510275, China