Affiliation: | 1. School of Mathematics and Statistics, Beijing Key Laboratory on MCAACI, Beijing Institute of Technology, Beijing, P.R. China School of Mathematics and Statistics, Northwestern Polytechnical University, Xi'an, Shaanxi, P.R. China;2. Department of Mathematics, European Centre of Excellence NTIS - New Technologies for the Information Society, University of West Bohemia, Pilsen, Czech Republic;3. School of Mathematics and Statistics, Beijing Key Laboratory on MCAACI, Beijing Institute of Technology, Beijing, P.R. China;4. School of Mathematics and Statistics, Beijing Key Laboratory on MCAACI, Beijing Institute of Technology, Beijing, P.R. China School of Mathematics and Statistics, Henan University, Kaifeng, P.R. China |