On Thursday 14.12.2017 CEID hosted Professor Sergios Theodoridis who delivered an extremely interesting talk entitled "A Tour to Deep Learning: From the Origins to Cutting Edge Research and Open Challenges”. Dr. Theodoridis is Professor of Signal Processing and Machine Learning in the Department of Informatics and Telecommunications of the University of Athens as well as Professor at the Chinese University of Hong Kong. In the early 1990s he was also Professor at CEID. He is a Fellow of IEEE and EURASIP and IEEE Fellow and Corresponding Fellow of the Royal Academy of Edinburgh. The talk was co-organized by the CEID Laboratory for Signal Processing and Communications and by the Greek Chapter of the ΙΕΕΕ Signal Processing Society.