[1] Fac Informat Studies, Novo Mesto 8000, Slovenia
[2] Tech Univ Berlin, Dept Struct Mech & Anal, D-10623 Berlin, Germany
[3] Store Steel Ltd, Zelezarska Cesta 3, Store 3220, Slovenia
[4] Univ Ljubljana, Fac Comp & Informat Sci, Ljubljana 1000, Slovenia
[5] Univ Catania, Dept Elect Elect & Comp Engn, I-95125 Catania, Italy