Dana Simian , University Lucian Blaga of Sibiu, Faculty of Sciences, Department of Computer Science, Sibiu, Romania E-mail: dana.simian@ulbsibiu.ro Ioana Moisil , University Lucian Blaga of Sibiu, "Hermann Oberth" Faculty of Engineering, Sibiu, Department of Computer Science and Automatic Control, Sibiu, Romania E-mail: ioana.moisil@ulbsibiu.ro Dan Dumitrescu , University Babes-Bolyai of Cluj Napoca , Faculty of Mathematics and Informatics, Department of Informatics, Cluj-Napoca, Romania E-mail: ddumitr@cs.ubbcluj.ro Emil M. Popa , University Lucian Blaga of Sibiu, Faculty of Sciences, Department of Computer Science, Sibiu, Romania E-mail: emilm_popa@yahoo.com Emil C. Popa , University Lucian Blaga of Sibiu , Faculty of Sciences, Department of Mathematics, Sibiu, Romania E-mail: emil.popa@ulbsibiu.ro Olga Miljkovic , Megatrend University of Belgrade, Serbia E-mail: olgamkg@sbb.co.yu Milan Tuba , University of Belgrade, Serbia E-mail: tubamilan@ptt.yu Nicolae Popoviciu , University Hyperion, Bucuresti, Romania E-mail: nic.popoviciu@yahoo.com Mihai Negru , University of Craiova, Romania E-mail: negrumih@yahoo.com Nicolae Pop , North University of Baia Mare, Romania E-mail: nic_pop2002@yahoo.com