Affiliation: | 1. Department of Mathematics, Seattle University Seattle, WA, 98122, USA;2. Department of Mathematical Sciences, Saginaw Valley State University, University Center, MI, 48710, USA;1. Department of Mechanical Systems Engineering, Hiroshima Institute of Technology, 2-1-1 Miyake Saeki-ku Hiroshima 731-5193, Japan;2. Faculty of Education and Welfare Science, Oita University, Dannoharu Oita-city 870-1192, Japan;1. Department of Mathematics and Mathematical Statistics, Umeå University, SE-90187 Umeå, Sweden;2. Department of Mathematics, Uppsala University, SE-75106 Uppsala, Sweden;3. Department of Mathematics, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden;1. School of Mathematical Sciences, Nankai University, Tianjin 300071, PR China;2. School of Mathematical Sciences and LPMC, Nankai University, Tianjin, 300071, PR China;1. University of Jyväskylä, Department of Mathematics and Statistics, Mattilanniemi, 40100 Jyväskylä, Finland;2. Università di Padova, Dipartimento di Matematica “T. Levi-Civita”, via Trieste 63, 35121 Padova, Italy |