Affiliation: | 1.Institut für Angewandte Mathematik,Universit?t Bonn,Bonn,Germany;2.Interdisziplin?res Zentrum für Komplexe Systeme,Universit?t Bonn,Bonn,Germany;3.St. Petersburg Department of the Steklov Institute of Mathematics,Russian Academy of Sciences,St. Petersburg,Russia;4.Faculty of Applied Mathematics and Control Processes,St. Petersburg State University,St. Petersburg,Russia |