27.03.2013, 15.00h Regular GK meeting

Talk from: Tsvetoslava Vateva-Gurova:   

Topic: Trust (Dependability & Security) Quantification

The problem statement will emphasise on trust issues in a typical Cloud system model. An approach to establish trust in the Cloud ecosystem upon authentication will be presented. The approach involves negotiation and quantitative aggregation of security parameters. 

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Talk from Sofia Nikitaki:

Topic:  Location Sensing with Sparse Approximation, Compressed Sensing, and Matrix Completion Theory

Location sensing can benefit a vast array of applications in pervasive computing environments. Fingerprinting techniques are increasingly used in many location-aware applications since they have been proved as highly accurate for determining the location of the user in dynamic indoor environments. In this talk, we present recent advantages in sparse approximation theory and compressed sensing and reformulate the localization problem as a sparse approximation problem in order to provide accurate location estimations. Moreover, we introduce an efficient training technique based on Matrix Completion theory for fingerprint based systems. The inherent correlation structure of the received signal-strength measurements is exploited in order to reduce the calibration phase by reconstructing the signature map from much less measurements. 

Sofia Nikitaki received the M.Sc. degree in Computer Science University of Paris-South XI, France and University of Crete (UOC), Greece in 2009 and the B.Sc. degree in Informatics and Telecommunications from National and Kapodistrian University of Athens in 2007. Since 2009 she has been working as a research assistant at the Signal Processing Laboratory (SPL) of the Foundation for Research and Technology-Hellas (FORTH). From October 2008 until July 2009, she was a research assistant at Laboratoire  de Recherche en Informatique (LRI)  in University of Paris XI.  She has been awarded with the Greek State Scholarships Foundation (IKY)  Erasums  Scholarship for undergraduate studies (2004-2005) and postgraduate studies (2007-2008). She is currently pursuing the Ph.D. degree at the UOC in the area signal processing with applications in wireless networks. Her research interests lie in the fields of sparse approximation theory, compressed sensing, matrix completion, Bayesian Interference, location sensing and wireless networking.