Institution: | 1. Department of Mathematical Sciences, Kent State University, 4314 Mahoning Avenue, Warren, OH 44483, USA;2. School of Mathematics and Statistics, Central China Normal University, Wuhan, Hubei, 430079, China;3. School of Mathematics and Physics, Hubei Polytechnic University, Huangshi, 435003, China;4. Faculty of Economics, Chiang Mai University, Chiang Mai 52000, Thailand |