Author(s):
1. Srbislav Aleksandrovic, Fakultet inženjerskih nauka Univerziteta u Kragujevcu, Serbia
2. Tomislav Vujinović, Serbia
3. Milentije Stefanović, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia
4. Vukić Lazić, Fakultet inženjerskih nauka Univerziteta u Kragujevcu, Serbia
5. Dragan Milosavljevic, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia