Parallel Computing and Complex Systems Group, Department of Computer Science, University of Leipzig Augustusplatz 10/11, 04109 Leipzig, Germany.|Parallel Computing and Complex Systems Group, Department of Computer Science, University of Leipzig Augustusplatz 10/11, 04109 Leipzig, Germany.|Parallel Computing and Complex Systems Group, Department of Computer Science, University of Leipzig Augustusplatz 10/11, 04109 Leipzig, Germany.