1. University of Macedonia,Department of Applied Informatics,Thessaloniki,Greece
2. Graduate School of Engineering, Nagoya Institute of Technology,Nagoya,Japan
3. Aristotle University of Thessaloniki,Department of Physics,Thessaloniki,Greece
4. International Hellenic University,Department of Computer Science,Kavala,Greece
5. University of Western Macedonia,Department of Informatics and Telecommunications Engineering,Kozani,Greece