Author(s):
1. Dragana Dimitrijević, Faculty of Mechanical Engineerning, Serbia
2. Predrag Živković, Faculty of Mechanical Engineering in Niš, Serbia
3. Jelena Janevski, Faculty of Mechanical Engineering in Niš, Serbia
4. Gordana Stefanović, Faculty of Mechanical Engineering in Niš, Serbia
5. Mirko Dobrnjac, Faculty of Mechanical Engineering, Republic of Srpska, Bosnia and Herzegovina