Faculty of Technology, Bielefeld University, D-33594 Bielefeld, Germany. asczyrba@TechFak.Uni-Bielefeld.DE|Faculty of Technology, Bielefeld University, D-33594 Bielefeld, Germany. asczyrba@TechFak.Uni-Bielefeld.DE|Faculty of Technology, Bielefeld University, D-33594 Bielefeld, Germany. asczyrba@TechFak.Uni-Bielefeld.DE