Author(s):
1. Jasna Radulovic, Fakultet inženjerskih nauka Univerziteta u Kragujevcu, Serbia
2. Milorad Bojic, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia
3. Dragan Adamović, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia