1. School of Engineering, Honghe University, Mengzi 661199, P. R. China
2. Faculty of Education, Final International University, Kyrenia Mersin 10, Turkey
3. Faculty of Education, Harran University, Sanliurfa, Turkey
4. Department of Mathematics, Firat University, Elazig, Turkey
5. School of Information Science and Technology, Yunnan Normal University, Yunnan, P. R. China