The University of Texas at San Antonio since Dec 2008
Associate Professor
University of Texas at San Antonio Oct 2003 - Dec 2008
Assistant Professor
Nokia Apr 1999 - Oct 2003
Senior Scientist
Tampere University of Technology Nov 1993 - 1999
Researcher, then Senior Researcher, then Coordinator of Tampere Int Centre on Signal Processing
IPIA 1988 - 1991
Researcher
Education:
Tampereen teknillinen korkeakoulu 1994 - 1997
PhD, DSP systems for Communications
Moscow Institute of Physics and Technology (State University) (MIPT) 1981 - 1987
MS, Radiophysics and Cybernetics
Moscow Institute of Physics and Technology (State University) (MIPT) 1981 - 1987
MS, Radioelectronics
Physics & Mathematics Charter school of Yerevan State University
Skills:
Signal Processing Algorithms Matlab Wireless Mobile Communications Latex Simulations Machine Learning Statistics Research Image Processing C++ Teaching C Digital Signal Processors Pattern Recognition Programming Data Analysis Computer Science Java Physics Computer Vision Project Management Sensors Program Management Wireless Technologies
Interests:
Advanced Gps Receivers New Technology Systems For Education Student Job Inquiries
Sos S. Agaian - San Antonio TX, US David Akopian - San Antonio TX, US Ravindranath C. Cherukuri - San Antonio TX, US Juan Pablo Perez - North Las Vegas NV, US Benjamin M. Rodriguez - Beavercreek OH, US
Assignee:
The Board of Regents of The University of Texas System - Austin TX
International Classification:
G06K 9/00
US Classification:
382100
Abstract:
Methods and systems for securing digital imagery are provided. In one respect, embedding, compression, encryption, data hiding, and other imaging processing techniques and systems may be provided for digital image security. In one non-limiting example, a method for producing a compressed and encrypted image is provided. An image may be converted into a binary bit stream, and the bit stream may be decomposed into a plurality of segments. A binary sequence based on a first key may be generated and may be used to generate a code matrix. A distance between the code matrix and the distance may be determined for each of the plurality of segments. Using a combined first and second key, a compressed and encrypted image may be obtained.
Crosscorrelation Interference Mitigating Position Estimation Systems And Methods Therefor
Catalin Lacatus - South Brunswick NJ, US David Akopian - San Antonio TX, US Mehdi Shadaram - San Antonio TX, US
Assignee:
Board of Regents, The University of Texas System - Austin TX
International Classification:
H04L 25/08 H04B 1/00
US Classification:
375346, 375130
Abstract:
Provided is a method that includes dynamically adjusting a GPS signature code to minimize the interference (e. g. , the cross-correlation interference) experienced due to one or more other GPS signals. Further provided is a method that includes adjusting the complexity of an adaptive solution to reduce the time and processing power associated with tracking a GPS signal.
Sos S. Agaian - San Antonio TX, US David Akopian - San Antonio TX, US Ravindranath C. Cherukuri - San Antonio TX, US Juan Pablo Perez - North Las Vegas NV, US Benjamin M. Rodriguez - Beavercreek OH, US Ronnie R. Sifuentes - San Antonio TX, US
International Classification:
G09C 5/00 G06K 9/00
US Classification:
380 54, 382100
Abstract:
Methods and systems for securing digital imagery are provided. In one respect, embedding, compression, encryption, data hiding, and other imaging processing techniques and systems may be provided for digital image security. In one non-limiting example, a method for producing a compressed and encrypted image is provided. An image may be converted into a binary bit stream, and the bit stream may be decomposed into a plurality of segments. A binary sequence based on a first key may be generated and may be used to generate a code matrix. A distance between the code matrix and the distance may be determined for each of the plurality of segments. Using a combined first and second key, a compressed and encrypted image may be obtained.
David Akopian - San Antonio TX, US Arsen Melkonyan - San Antonio TX, US Murillo Pontual - San Antonio TX, US Grant Huang - San Antonio TX, US Andreas Robert Gampe - San Antonio TX, US
A remote laboratory gateway enables a plurality of students to access and control a laboratory experiment remotely. Access is provided by an experimentation gateway, which is configured to provide secure access to the experiment via a network-centric, web-enabled interface graphical user interface. Experimental hardware is directly controlled by an experiment controller, which is communicatively coupled to the experimentation gateway and which may be a software application, a standalone computing device, or a virtual machine hosted on the experimentation gateway. The remote laboratory of the present specification may be configured for a software-as-a-service business model.
System And Method For Global Navigation Satellite System (Gnss) Spoofing Detection
- Austin TX, US David Akopian - San Antonio TX, US Nikolaos Gatsis - San Antonio TX, US
International Classification:
G01S 19/21
Abstract:
A global navigation satellite system (GNSS) spoofing detection and classification technique is provided. An optimization problem is formulated at the baseband correlator domain by using an optimization algorithm such as the Least Absolute Shrinkage and Selection Operator (LASSO) algorithm, for example. A model of correlator tap outputs of the intended received signal is created to form a dictionary of pre-computed waveform functions (e.g., triangle-like-shaped functions). Sparse signal processing can be leveraged to choose a decomposition of pre-computed waveform functions from the dictionary. The optimal solution of this minimization problem can discriminate the presence of a potential spoofing attack peak by observing the decomposition of two different code-phase values (authentic and spoofed) in a sparse vector output. A threshold can be used to mitigate false alarms. Furthermore, a variation of the minimization problem can be provided that enhances the dictionary to a higher resolution.
Systems, Methods, And Computer Programs For Wireless Local Area Network Localization
Disclosed are various embodiments that enable the identification of the location of a computing device based on radio data. A radio map can be identified for an area. The computing device can measure signal strengths to reference points. The signal strengths can be compared to the radio map. The computing device can determine its location based on the comparison of the signal strengths to the radio map.
Method And System For Detecting And Mitigating Time Synchronization Attacks Of Global Positioning System (Gps) Receivers
Nikolaos Gatsis - San Antonio TX, US David Akopian - San Antonio TX, US Ahmad Fayez Taha - San Antonio TX, US
Assignee:
Board of Regents, The University of Texas System - Austin TX
International Classification:
G01S 19/21 G01S 19/25
Abstract:
A system and method are provided for detecting and estimating time synchronization attacks (TSAs) on Global Positioning System (GPS) receivers. The system and method can be implemented to address gaps in the known or proposed TSA detection solutions. In particular, the system and method can be implemented to provide a TSA countermeasure solution that: 1) provides a comprehensive countermeasure against different types of TSAs; 2) allows the GPS receiver to continue its normal operation, which is especially beneficial in Phasor Measurement Unit (PMU) applications where the network's normal operation cannot be interrupted; in other words, the solution not only detects TSAs, but also mitigates their effects so that the network can continue its normal operation; and 3) is relatively simple and capable of being integrated with current GPS receivers without having to alter the circuitry of the GSP receivers.
Systems, Methods, And Computer Programs For Wireless Local Area Network Localization
Disclosed are various embodiments that enable the identification of the location of a computing device based on radio data. A radio map can be identified for an area. The computing device can measure signal strengths to reference points. The signal strengths can be compared to the radio map. The computing device can determine its location based on the comparison of the signal strengths to the radio map.