1. Information Science and Technology College, Dalian Maritime University, Dalian, China
2. School of Computer Science and Technology, Dalian University of Technology, Dalian, China
3. School of Computing and Mathematics, Ulster University, Northern Ireland, UK
4. Neusoft Institute of Modern Industry, Dalian Neusoft University of Information, Dalian, China
5. School of Computer Science and Technology, Shandong Jianzhu University, Jinan, China