The Scientific Journal
FACTA UNIVERSITATIS
Series Mathematics and Informatics
ISSN 0352 – 9665



Editor-in-Chief
Predrag S. Stanimirović
University of Niš
Faculty of Science and Mathematics
Department of Computer Science
P.O. Box 224, Višegradska 33, 18000 Niš, Serbia

Phone: +381 18 224 492
Fax: +381 18 533 014
e-mail: pecko@pmf.ni.ac.rs

Associate editor
Dragana Cvetković-Ilić
Faculty of Science and Mathematics
Department of Mathematics,

e-mail: dragana@pmf.ni.ac.rs,

Founding Editor
Gradimir V. Milovanović
Mathematical Institute of the Serbian Academy of Sciences and Arts, Belgrade, Serbia

AREA EDITORS:

Aleksandar Cvetković*
      Approximation Theory, Numerical Analysis

Dragana Cvetković Ilić*
      Linear Algebra, Operator Theory

Jelena Ignjatović*
      Algebra, Fuzzy Mathematics, Theoretical Computer Science

Ljubiša Kocić**
     Fractal Geometry, Chaos Theory, Computer Aided Geometric Design

Jelena Manojlović*
      Differential Equations

Gradimir Milovanović
      Approximation Theory, Numerical Analysis

Emina Milovanović**
     Parallel Computing, Computer Architecture

Dijana Mosić*
      Mathematical and Functional Analysis

Miroslav Ristić*
      Statistics, Time Series Analysis

Predrag Stanimirović*
      Symbolic and Algebraic Computation, Operations Research

Milena Stanković**
      Internet Technologies, Software Engineering

Dragan Stevanović*
      Discrete Mathematics, Graph and Combinatorial Algorithms

Marko Petković*
      Numerical Linear Algebra, Information Theory and Coding, Determinant Computation

Marko Miladinović*
      Numerical Linear Algebra,Optimization Theory

Milan Bašić*
      Graph Theory, Automata Theory, Computer Communication Networks, Quantum Information Theory, Number Theory

Milan Tasić*
      Data Storage, Web Programming



EDITORIAL BOARD:

R. P. Agarwal, Melbourne, FL, USA
O. Agratini, Cluj-Napoca, Romania
S. Bogdanović, Niš, Serbia
M. Ćirić, Niš, Serbia
D. Cvetković, Belgrade, Serbia
D. K. Dimitrov, Sao Jose do Rio Preto, Brazil
S. S. Dragomir, Victoria, Australia
D. S. Djordjevic, Niš, Serbia
M. Droste, Leipzig, Germany
A. Guessab, Pau, France
A. Ivić, Belgrade, Serbia
B. S. Kašin, Moscow, Russia
Lj. Kočinac, Niš, Serbia
G. Mastroianni, Potenza, Italy
P. S. Milojević, Newark, NJ, USA
I. Ž. Milovanović, Niš, Serbia
Lj. Petković, Niš, Serbia
S. Pilipović, Novi Sad, Serbia
V. Rakočević, Niš, Serbia
Th. M. Rasssias, Athens, Greece
S. Saitoh, Kiryu, Japan
H. M. Srivastava, Victoria, Canada
R. Stanković, Niš, Serbia
A. Tepavčević, Novi Sad, Serbia
H. Vogler, Dresden, Germany

* University of Niš, Faculty of Science and Mathematics, Department of Mathematics and Informatics, P.O. Box 224, Višegradska 33, 18000 Niš, Serbia
** University of Niš, Faculty of Electronic Engineering, P.O. Box 73, 18000 Niš, Serbia

Technical Editor: Aleksandar Ilić, Faculty of Science and Mathematics, Department of Mathematics and Informatics, P.O. Box 224, Višegradska 33, 18000 Niš, Serbia