Faculty of Technology, Bielefeld University, Bielefeld, Germany. wolfgang.gerlach@cebitec.uni-bielefeld.de|Faculty of Technology, Bielefeld University, Bielefeld, Germany. wolfgang.gerlach@cebitec.uni-bielefeld.de|Faculty of Technology, Bielefeld University, Bielefeld, Germany. wolfgang.gerlach@cebitec.uni-bielefeld.de|Faculty of Technology, Bielefeld University, Bielefeld, Germany. wolfgang.gerlach@cebitec.uni-bielefeld.de|Faculty of Technology, Bielefeld University, Bielefeld, Germany. wolfgang.gerlach@cebitec.uni-bielefeld.de