Affiliation: | aInternational Center for Mathematical Modelling in Physics and Cognitive Sciences MSI, Växjö University, SE-351 95, Växjö, Sweden;bDepartment of Mathematics, St. Petersburg State Architecture and Civil Engineering University, 2 Krasnoarmeiskaya 4, 190005, St. Petersburg, Russia;cDepartment of Applied Mathematics and Control Processes, St. Petersburg State University, Universitetskii pr.-35, 198504 St. Petersburg, Russia |