1. Department of Mathematics and Computer, Tongling University, Tongling, Anhui 244061, China
2. Department of Electric Engineering, Tongling University, Tongling, Anhui 244061, China
3. Engineering Technology Research Center of Optoelectronic Technology Appliance, Anhui Province, Tongling, Anhui 244061, China
4. School of Information Engineering, Shaoguan University, Shaoguan, Guangdong 512005, China