1. Faculty of Electrical Engineering, Computer Science and Information Technology Osijek, J.J. Strossmayer University of Osijek, Kneza Trpimira 2B, 31000 Osijek, Croatia
2. University of Ljubljana, Faculty of Education, Kardeljeva ploščad 16, 1000 Ljubljana, Slovenia
3. Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia