1. The College of Information Engineering, Xiangtan University, Xiangtan 411105, China
2. Key Laboratory of Intelligent Computing & Information, Ministry of Education, Xiangtan University, Xiangtan 411105, China
3. School of Computer Science & Engineering, Hunan University of Science and Technology, Xiangtan 411201, China
4. Department of Information and Computer Engineering, Ajou University, Suwon 443749, Republic of Korea
5. Graduate School of Advanced Integration Science, Chiba University, Chiba 2638522, Japan