Affiliation: | 1. Mathematical Institute, Serbian Academy of Sciences and Arts, Kneza Mihaila 36, P.O. Box 367, 11001 Belgrade, Serbia;2. Center for Information Science and Technology, Temple University, 322 Wachman Hall, 1805 North Broad Street, Philadelphia, PA 19122, USA;3. Faculty of Transport and Traffic Engineering, University of Belgrade, Vojvode Stepe 305, 11010 Belgrade, Serbia |