1. Institute of Computer Science and Applied Mathematics, Cognitive Systems Group, Christian-Albrechts-University of Kiel, Preußerstr. 1-9, 24105 Kiel, Germany
2. GSF – National Research Center for Environment and Health, Institute of Medical Informatics and Health Services Research, MEDIS, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany