1. Bonn-Rhein-Sieg University of Applied Sciences, TREE Institute Grantham-Allee 20 53757 Sankt Augustin Germany
2. Dr. Reinold Hagen Stiftung, Research and Development Kautexstraße 53 53229 Bonn Germany
3. Rikutec Germany GmbH & Co. KG Graf-Zeppelin-Straße 1–5 57610 Altenkirchen Germany
4. Otto-von-Guericke-University Magdeburg, Institute of Mechanics Universitätsplatz 2 39106 Magdeburg Germany