1. School of Mathematics and Statistics, Chongqing Jiaotong University, Chongqing, China
2. China Science IntelliCloud Technology Company Ltd, Hefei, China
3. School of Information Science and Technology, Chongqing Jiaotong University, Chongqing, China
4. Department of Electrical and Computer Engineering, Rowan University, Glassboro, NJ, USA