1. College of Mathematics and Statistics, Jishou University, Jishou, People's Republic of China
2. Department of Mathematics, Aligarh Muslim University, Aligarh, India
3. Department of Mathematics and Statistics, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
4. Center for General Education, China Medical University, Taichung, Taiwan
5. Research Center for Interneural Computing, China Medical University Hospital, Taichung, Taiwan