1. Fraunhofer Institute for Industrial Mathematics ITWM,Kaiserslautern,Germany,67663
2. SINTEF Digital,Department of Mathmatics and Cybernetics,Trondheim,Norway,N-7037
3. Norwegian University of Science and Technology,Department of Engineering Cybernetics,Trondheim,Norway,N-7491
4. Technische Universität Ilmenau,Control Engineering Group,Ilmenau,Germany,98684