Author(s):
1. Ljiljana Veljović, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia
2. Dragan Milosavljevic, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia
3. Gordana Bogdanovic, Faculty of Engineering, University of Kragujevac, Sestre Janjić 6, 34000 Kragujevac, Srbija 2IMW Ins, Serbia
4. Aleksandar Radaković, State University of Novi Pazar, Serbia