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National Conference on Radio Science (NSRC)

作者： Heba M. Elhosany Hossam E. Hossin Hassan B. Kazemian Osama S. Faragallah Master Student in Digital Signal Processing Menoufia University Egypt Department of Electronics and Electrical Communications Menoufia University Menouf Egypt Professor and Director of Intelligent System Research Center Department of Computers Science & Engineering Menoufia University Menouf Egypt

This paper presents an implementation of 2-D chaotic Baker map using different modes of operations after applying the Fractional Fourier Transform (FrFT) on digital images. The proposed image cryptosystem implements the chaotic Baker map scrambling using three different modes of operation; Cipher Block Chain (CDC), Cipher Feed-Back (CFB), Output Feed-Back (OFB), in which the Initialization Vector (IV) works as the main key. We examine its implementation for digital images along with its detailed security analysis. The security analysis includes the statistical analysis, the histogram analysis, the correlation coefficient metric, the maximum deviation metric, the irregular deviation metric, the noise immunity, the processing time, and the key space analysis. Experiments and results verify and prove that the proposed image cryptosystem is highly secure from the cryptographic viewpoint, more immune to noise, has high key sensitivity, and takes less processing time.

关键词： Encryption Educational institutions Chaotic communication Time frequency analysis

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Measurement-Device-Independent Quantum Key Distribution

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Physical Review Letters 2012年第13期108卷 130503-130503页

作者： Hoi-Kwong Lo Marcos Curty Bing Qi Center for Quantum Information and Quantum Control Department of Electrical & Computer Engineering and Department of Physics University of Toronto Toronto Ontario M5S 3G4 Canada Escuela de Ingeniería de Telecomunicación Department of Signal Theory and Communications University of Vigo Vigo Pontevedra 36310 Spain

How to remove detector side channel attacks has been a notoriously hard problem in quantum cryptography. Here, we propose a simple solution to this problem—measurement-device-independent quantum key distribution (QKD). It not only removes all detector side channels, but also doubles the secure distance with conventional lasers. Our proposal can be implemented with standard optical components with low detection efficiency and highly lossy channels. In contrast to the previous solution of full device independent QKD, the realization of our idea does not require detectors of near unity detection efficiency in combination with a qubit amplifier (based on teleportation) or a quantum nondemolition measurement of the number of photons in a pulse. Furthermore, its key generation rate is many orders of magnitude higher than that based on full device independent QKD. The results show that long-distance quantum cryptography over say 200 km will remain secure even with seriously flawed detectors.

关键词： QUANTUM cryptography signal detection PHOTON detectors QUANTUM teleportation LIGHT sources LASER measurement

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A review on low-complexity structures and algorithms for the correction of mismatch errors in time-interleaved ADCs

A review on low-complexity structures and algorithms for the...

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Annual IEEE Northeast Workshop on Circuits and Systems (NEWCAS)

作者： Christian Vogel Matthias Hotz Shahzad Saleem Katharina Hausmair Michael Soudan FTW Telecommunications Research Center Vienna Vienna Austria Department of Electrical Engineering National University of Computer and Emerging Sciences Islamabad Pakistan Signal Processing and Speech Communication Laboratory Graz University of Technology Graz Austria

In this paper we review the progress in the design of low-complexity digital correction structures and algorithms for time-interleaved ADCs over the last five years. We devise a discrete-time model, state the design problem, and finally derive the algorithms and structures. In particular, we discuss efficient algorithms to design time-varying correction filters as well as iterative structures utilizing polynomial based filters. Finally, we give an outlook to future research questions.

关键词： Circuits and systems Complexity theory Algorithm design and analysis Calibration Time varying systems Polynomials Time frequency analysis

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Information Generation and Lagrangian Coherent Structures in Multiscroll Attractors *

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IFAC Proceedings Volumes 2012年第12期45卷 93-98页

作者： Filipe I. Fazanaro Diogo C. Soriano Ricardo Suyama Marconi K. Madrid Romis Attux José Raimundo de Oliveira Modular Robotic Systems Laboratory (LSMR) Department of Computer Engineering and Industrial Automation (DCA) School of Electrical and Computer Engineering (FEEC) UNICAMP Brazil Centro de Engenharia Modelagem e Ciências Sociais Aplicadas Universidade Federal do ABC (UFABC) Santo André Brazil LSMR Department of Energy Control and Systems (DSCE) FEEC UNICAMP Laboratory of Signal Processing for Communications (DSPCom) DCA FEEC UNICAMP

The present work aims to apply a recently alternative approach to estimate the Lyapunov exponents that is suitable for such piecewise linear model in order of characterizing - with the aid of the metric entropy - the degree of information generated by several kinds of multiscroll attractors. Another analytical path is followed with the extraction of the corresponding Lagrangian coherent structures, which allows the determination of the dynamical system separatrices and also of the folding/stretching behavior that results in chaos. Overall, the reported study can be understood as an investigation, from distinct theoretical standpoints, of key aspects regarding the dynamic behavior of systems capable of engendering multiscroll structures.

关键词： chaotic behavior fractal dimension information generation Lagrangian coherent structures Lyapunov exponents multiscroll chaotic attractors non-smooth models

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Using simple relays to improve physical-layer security

Using simple relays to improve physical-layer security

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IEEE International Conference on communications in China (ICCC)

作者： Gan Zheng Jiangyuan Li Kai-Kit Wong Athina P. Petropulu Björn Ottersten Interdisciplinary Centre for Security Reliability and Trust (SnT) University of Luxembourg Luxembourg Department of Electrical and Computer Engineering Rutgers The State University of New Jersey USA Department of Electronic and Electrical Engineering University College London London UK Signal Processing Laboratory ACCESS Linnaeus Center KTH Royal Institute of Technology Sweden

This paper studies different uses of two cooperating relays to improve the secrecy rate of a wiretap channel. These two relays are assumed to perform only simple functions: either amplify-and-forward (AF) or jamming. Complex functions such as decode-and-forward (DF) are not considered. We study three modes of cooperation: i) cooperative jamming (CJ), ii) AF-aided beamforming and iii) mixed AF-aided beamforming and CJ, all with individual relay power constraints. While i) is known in the literature, our efforts are spent on ii) and iii). In particular, for iii), we assume that the jamming signals in two communication stages are correlated, giving rise to improved performances. We also propose a heuristic approach for selecting the appropriate cooperating mode. Simulation results illustrate the performance gain of each scheme under different channel conditions and the effectiveness of the proposed mode selection method.

关键词： Relays Jamming Interference Security Protocols Noise Physical layer

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Performance analysis of indoor OFDM optical wireless communication systems

Performance analysis of indoor OFDM optical wireless communi...

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IEEE Conference on Wireless communications and Networking

作者： Raed Mesleh Hany Elgala Harald Haas Electrical Engineering Department and Sensor Networks and Cellular Systems (SNCS) research Center University of Tabuk Tabuk Saudi Arabia Jacobs University Bremen Bremen Germany Institute for Digital Communications Joint Research Institute for Signal and Image Processing University of Edinburgh Edinburgh UK

In this paper, the performance of indoor OFDM (orthogonal frequency division multiplexing) optical wireless (OW) communication systems in the presence of LED (light emitting diode) clipping distortions is analyzed. Two indoor OW OFDM techniques are considered. An ACO-OFDM (asymmetrically clipped optical OFDM) system produces half-wave symmetry time signal at the output of the OFDM modulator by special assignment of subcarriers. Therefore, bipolar-unipolar conversion is achieved by clipping the signal at the zero level at the expense of data rate reduction. The second technique, called DCO-OFDM (DC-biased optical OFDM), assigns data to all possible subcarriers to increase the data rate. However, half-wave symmetry signals cannot be achieved and a DC bias is needed to convert the bipolar signal to a unipolar signal before modulating the LED intensity. The performance of these systems, in terms of average electrical OFDM signal power versus bit-error-ratio (BER), DC power consumption, and transmitted optical power in the presence of additive white Gaussian noise (AWGN) channel and considering a practical LED model, are studied. Analytical results are validated through Monte Carlo simulation results and the results demonstrate close match. The results clearly highlight that LED clipping has significant impact on the performance of these systems and system design should consider optimizing the OFDM signal power, DC bias point, and LED dynamic range.

关键词： OFDM Light emitting diodes Optical distortion Optical sensors Optical modulation Noise

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Denoising diffusion-weighted MR magnitude image sequences using low rank and edge constraints

Denoising diffusion-weighted MR magnitude image sequences us...

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IEEE International Symposium on Biomedical Imaging

作者： Fan Lam S. Derin Babacan Justin P. Haldar Norbert Schuff Zhi-Pei Liang Department of Electrical and Computer Engineering and Beckman Institute for Advanced Science and Technology University of Illinois Urbana-Champaign USA Signal and Image Processing Institute the Dornsife Cognitive Neuroscience Imaging Center and the Brain and Creativity Institute University of Southern California USA Department of Radiology and Biomedical Imaging VA Medical Center University of California San Francisco USA

ISBN: (纸本)9781457718571

This paper addresses the denoising problem associated with diffusion MR imaging. Building on previous approaches to this problem, this paper presents a new method for joint denoising of a sequence of diffusion-weighted (DW) magnitude images. The proposed method uses a maximum a posteriori (MAP) estimation formulation to incorporate a Rician likelihood (for modeling the noisy magnitude data), a low rank model (for the DW image sequences) and a spatial prior (for imposing joint edge constraints). An efficient algorithm to solve the associated optimization problem is also described. The proposed method has been evaluated using both simulated and experimental diffusion tensor imaging (DTI) data, which yields very encouraging results both qualitatively and quantitatively.

关键词： Noise reduction Noise Image edge detection Rician channels Diffusion tensor imaging

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Lecture Notes in computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics): Preface

Lecture Notes in Computer Science (including subseries Lectu...

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Lecture Notes in computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2012年 7191 LNCS卷 V-VII页

作者： Cichocki, Andrzej Theis, Fabian Yeredor, Arie Zibulevsky, Michael Helmholtz Center Munich Institute of Bioinformatics and Systems Biology Ingolstädter Landstr. 1 85764 Neuherberg Germany Riken Brain Science Institute Laboratory for Advanced Brain Signal Processing 2-1 Hirosawa Wako-shi 351-0198 Saitama Japan Tel-Aviv University School of Electrical Engineering Tel-Aviv 69978 Israel Technion - Israel Institute of Technology Department of Computer Science Haifa 32000 Israel

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A comparative study of different classifier selection and fusion algorithms in a multimodal identity verification system

A comparative study of different classifier selection and fu...

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作者： Sedighi, Vahid Sadeghi, Mohammad T. Kittler, Josef Signal Processing Research Group Department of Electrical and Computer Engineering Yazd University Yazd Iran Center for Vision Speech and Signal Processing University of Surrey Guildford Surrey United Kingdom

ISBN: (纸本)9789898425478

A comparative study of a set of classifier selection and fusion algorithms for combining face and speech modalities in a multimodal biometric system is performed. Our text independent speaker verification system uses MFCC features along with a GMM method for speaker modelling and the GMM-UBM classifier for matching. The face verification system uses different similarity measures in two appearance based representation spaces namely PCA and LDA. The adopted authentication systems are fused at the matching score level to realise a system which can meet more challenging and varying requirements. The utility of two classifier selection methods, namely the sequential search method and Particle Swarm Optimisation (PSO) algorithm, along with two matching score fusion rules, the weighted averaging rule and SVM, is experimentally studied. In our extensive experimentation on the BANCA database, we demonstrate that by combining the PSO classifier selection method and the SVM fusion rule, the performance of the resulting decision making system is consistently superior.

关键词： Particle swarm optimization (PSO)

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Rapid Identification of Epileptogenic Sites in the Intracranial EEG

Rapid Identification of Epileptogenic Sites in the Intracran...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society

作者： R. Yadav M. N. S. Swamy R. Agarwal Center for Signal Processing and Communications (CENSIPCOM) Department of Electrical and Computer Engineering Concordia University

ISBN: (纸本)9781424441211

The paper presents a novel computationally simple, easy-to-interpret compressed EEG display for multichannel intracranial EEG recordings. The compressed display is based on the level of sharp activity (relative sharpness index (RSI)) in the EEG, which profoundly increases during paroxysmal activities. RSI is graphically presented as a color-intensity plot that allows compressing several hours of EEG into a single display page. RSI display is a bird's-eye-view of the EEG that may reveal seizure evolution ('build-up'), seizure precursors, or sites associated with the seizures. We present examples from two patients to illustrate the method's ability to identify epileptogenic sites that may be difficult to observe in the conventional review process. RSI is compared with the color density spectral array (CDSA) and amplitude integrated EEG (aEEG) display. Examples demonstrate the RSI display to be simple, easy to interpret, computationally light and fast enough for online application.

关键词： EEG Seizure detection Compressed EEG display CDSA AEEG

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