1. Department of Electrical and Electronics Engineering, University of West Attica, Ancient Olive Grove Campus, Egaleo, 12241 Athens, Greece
2. Department of Applied Mathematics and Physics, Graduate School of Informatics, Kyoto University, Sakyo, Kyoto 606-8501, Japan
3. Department of Physics, International Hellenic University, 65404 Kavala, Greece
4. National Observatory of Athens, Metaxa and Vasileos Pavlou, Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, Penteli, 15236 Athens, Greece
5. Department of Electrical Engineering, Computer Engineering and Informatics, School of Engineering, Frederick University, Nicosia 1036, Cyprus