1. Brno University of Technology , Faculty of Information Technology , Božetěchova 2 , , Brno , Czech Republic
2. Brno University of Technology , Faculty of Information Technology , Božetěchova 2 , , Brno , Czech Republic ; IT4Innovations, VŠB Technical University of Ostrava , 17. listopadu 15/2172 , , Ostrava-Poruba , Czech Republic