Neural Networks Research Centre, Helsinki University of Technology P,O, Box 9800, FIN-02015 HUT, Finland. samuel.kaski@hut.fi|Neural Networks Research Centre, Helsinki University of Technology P,O, Box 9800, FIN-02015 HUT, Finland. samuel.kaski@hut.fi|Neural Networks Research Centre, Helsinki University of Technology P,O, Box 9800, FIN-02015 HUT, Finland. samuel.kaski@hut.fi|Neural Networks Research Centre, Helsinki University of Technology P,O, Box 9800, FIN-02015 HUT, Finland. samuel.kaski@hut.fi|Neural Networks Research Centre, Helsinki University of Technology P,O, Box 9800, FIN-02015 HUT, Finland. samuel.kaski@hut.fi|Neural Networks Research Centre, Helsinki University of Technology P,O, Box 9800, FIN-02015 HUT, Finland. samuel.kaski@hut.fi