1. Department of Electrical and Computer Engineering, University of the Peloponnese, Patras, Greece
2. Department of Computer Engineering & Informatics, University of Patras, Patras, Greece
3. School of Engineering and Computer Science, University of Hertfordshire, United Kingdom
4. Department of Electrical and Computer Engineering, University of the Peloponnese, Greece
5. Computer Technology Institute and Press “Diophantus”, Patras, Greece