1. School of Business, Economics and Social Sciences, Department of Business Administration, University of West Attica, 250 Thivon & P. Ralli str, 12244 Egaleo, Greece
2. School of Electrical and Computer Engineering, Electric Power Division, Photometry Laboratory, National Technical University of Athens, 15780 Athens, Greece
3. Department of Business Administration, DigiT.DSS.Lab, University of West Attica, 250 Thivon & P. Ralli str, 12244 Egaleo, Greece