Author(s):
1. Mladen Tomić, The School of Higher Technical Professional Education, Niš, Serbia
2. Predrag Živković, Faculty of Mechanical Engineering in Niš, Serbia
3. Mića Vukić , Faculty of Mechanical Engineering in Niš, Serbia
4. Mirko Dobrnjac, Faculty of Mechanical Engineering, Republic of Srpska, Bosnia and Herzegovina
5. Dragana Dimitrijević, Faculty of Mechanical Engineerning, Serbia

Final paper