1. Department of Mathematics, School of Mathematics and Statistics, Changchun University of Science and Technology 1 , Changchun 130022, People’s Republic of China
2. Department of Applied Statistics, School of Mathematics and Statistics, Changchun University of Science and Technology 2 , Changchun 130022, People’s Republic of China
3. School of Mathematics and Statistics, Beijing Jiaotong University 3 , Beijing 100044, People’s Republic of China