1 Faculty of Electrical Engineering and Information, University of Zilina, Univerzitna 1, 01026 Zilina, Slovakia.
2 Center for Basic and Applied Research, Faculty of Informatics and Management, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic.
3 Malaysia Japan International Institute of Technology (MJIIT), Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, Kuala Lumpur 54100, Malaysia.
4 Department of Software Engineering, University of Szeged, H-6720 Szeged, Hungary.