1. Faculty of Electrical Engineering, Automatics, Computer Science and Biomedical Engineering, Department of Applied Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland
2. Faculty of Management, Department of Statistics and Econometrics, Częstochowa University of Technology, Armii Krajowej 19B, 42-200 Częstochowa, Poland