1. School of Finance, Anhui University of Finance and Economics No. 962 Caoshan Road Bengbu 233030 Anhui China
2. School of Electrical and Information Engineering Anhui University of Science and Technology No. 168 Taifeng Street Huainan 232001 Anhui China
3. School of Mathematics and Statistics Xinyang Normal University No. 237 Nanhu Road Xinyang 464000 Henan China