Affiliation: | aInstitute of Mechanical Engineering Problems, V.O., Bolshoi pr., 61, 199178 St.-Petersburg, Russia;bDelft Institute of Applied Mathematics, TU Delft, P.O. Box 5031, 2600 GA Delft, The Netherlands;cMathematisches Institut, Universität zu Köln, Weyertal 86–90, 50931 Köln, Germany |