1. School of Computer Science and Technology, Zhejiang Normal University, Jinhua, China
2. Key Laboratory of Intelligent Education Technology and Application of Zhejiang Province, the School of Mathematical Sciences, Zhejiang Normal University, Jinhua, China
3. School of Mathematics, Southeast University, Nanjing, China
4. Deanship of Graduate Studies and Research, Ahlia University, Manama, Bahrain