| Affiliation: | 1. HLM, Institute of Mathematics, Academy of Mathematics & System Sciences, Chinese Academy of Sciences, Beijing 100190, PR China;2. School of Mathematics, University of Chinese Academy of Sciences, Beijing 100049, PR China;1. Department of Mathematical Sciences, Faculty of Science, Yamagata University, Kojirakawa-machi 1-4-12, Yamagata 990-8560, Japan;2. Graduate School of Science and Engineering, Yamagata University, Kojirakawa-machi 1-4-12, Yamagata 990-8560, Japan;1. Department of Applied Mathematics, Ulyanovsk State University, Ulyanovsk 432970, Russia;2. Dipartimento di Ingegneria, Università di Palermo, Viale delle Scienze, Ed. 8, 90128 Palermo, Italy;1. Department of Mathematics, Chonnam National University, Gwangju 61186, Republic of Korea;2. Department of Mathematics, Iowa State University, Ames, IA 50011, USA |
