1. College of Computer Science and Engineering, Shandong University of Science and Technology, Qindao, Shandong 266590, China
2. Department of Mathematics and Computer Science, Brandon University, Brandon, MB R7A 6A9, Canada
3. Research Centre for Interneural Computing, China Medical University, Taichung 406040, Taiwan
4. Department of Computer Science Electrical Engineering and Mathematical Sciences, Western Norway University of Applied Sciences, Inndalsveien 28, 5063 Bergen, Norway