1. Institute AIFB, University of Karlsruhe, Karlsruhe, Germany
2. Institute AIFB, University of Karlsruhe, Karlsruhe, Germany and Ontoprise GmbH, Karlsruhe, Germany
3. Institute AIFB, University of Karlsruhe, Karlsruhe, Germany and Ontoprise GmbH, Karlsruhe, Germany and FZI Research Center for Information Technologies, KM Department (WIM), Karlsruhe, Germany and L3S Learning Lab, Hannover/Karlsruhe, Germany