1. Dept. of Computer Vision and Machine Learning, MPI Informatics, Germany. xhong@lst.uni-saarland.de
2. Dept. of Language Science and Technology and Dept. of Computer Science, Saarland University, Germany. xhong@lst.uni-saarland.de
3. Saarland Informatics Campus, Saarbrücken, Germany. xhong@lst.uni-saarland.de
4. Dept. of Philosophy, Linguistics, and Theory of Science, University of Gothenburg, Sweden. asad.sayeed@gu.se
5. Dept. of Language Science and Technology and Dept. of Computer Science, Saarland University, Germany. kmehra@lst.uni-saarland.de
6. Saarland Informatics Campus, Saarbrücken, Germany. kmehra@lst.uni-saarland.de
7. Dept. of Language Science and Technology and Dept. of Computer Science, Saarland University, Germany. vera@lst.uni-saarland.de
8. Saarland Informatics Campus, Saarbrücken, Germany. vera@lst.uni-saarland.de
9. Dept. of Computer Vision and Machine Learning, MPI Informatics, Germany. schiele@mpi-inf.mpg.de
10. Saarland Informatics Campus, Saarbrücken, Germany. schiele@mpi-inf.mpg.de