Author(s):
1. Jelena Janevski, Faculty of Mechanical Engineering in Niš, Serbia
2. Branislav Stojanovic, Faculty of Mechanical Engineering in Niš, 3. Mladen Stojiljković, Faculty of Mechanical Engineering in Niš, Serbia
4. Predrag Živković, Faculty of Mechanical Engineering in Niš, Serbia
5. Mirko Dobrnjac, Faculty of Mechanical Engineering, Republic of Srpska, Bosnia and Herzegovina
6. Mića Vukić , Faculty of Mechanical Engineering in Niš, Serbia