1. Department of International Trade; Technological Educational Institute of Western Macedonia at Kastoria; PO Box 30 Kastoria GR-521 00 Greece
2. Department of Informatics Engineering; Technological Educational Institution of Western Macedonia at Kastoria; Kastoria Greece
3. Escuela Politécnica Superior de Zamora and Scientific Computing Group; Universidad de Salamanca; Salamanca Spain
4. Group of Modern Computational Methods; Ural Federal University; 19 Mira Street Ekaterinburg 620002 Russia
5. Laboratory of Computational Sciences, Department of Informatics and Telecommunications, Faculty of Economy, Management and Informatics; University of Peloponnese; Tripolis 221 00 Greece