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digital-signals
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Source estimation in noisy sparse component analysis
, Article 2007 15th International Conference onDigital Signal Processing, DSP 2007, Wales, 1 July 2007 through 4 July 2007 ; July , 2007 , Pages 219-222 ; 1424408822 (ISBN); 9781424408825 (ISBN) ; Babaiezadeh, M ; Jutten, C ; Sharif University of Technology
2007
Abstract
In this paper, a new algorithm for Sparse Component Analysis (SCA) in the noisy underdetermined case (i.e., with more sources than sensors) is presented. The solution obtained by the proposed algorithm is compared to the minimum l1 -norm solution achieved by Linear Programming (LP). Simulation results show that the proposed algorithm is approximately 10 dB better than the LP method with respect to the quality of the estimated sources. It is due to optimality of our solution (in the MAP sense) for source recovery in noisy underdetermined sparse component analysis in the case of spiky model for sparse sources and Gaussian noise. © 2007 IEEE
Design and Implementation of Electrical Dust Control System Using DSP Processors
, M.Sc. Thesis Sharif University of Technology ; Vosoughi Vahdat, Bijan (Supervisor) ; Hashemi, Matin (Co-Advisor)Digesting network traffic for forensic investigation using digital signal processing techniques
, Article IEEE Transactions on Information Forensics and Security ; Volume 14, Issue 12 , 2019 , Pages 3312-3321 ; 15566013 (ISSN) ; Jahangir, A.H ; Kazemi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
One of the most important practices of cybercrime investigations is to search a network traffic history for an excerpt of traffic, such as the disclosed information of an organization or a worm's signature. In post-mortem investigations, criminals and targets are detected by attributing the excerpt to payloads of traffic flows. Since it is impossible to store the high volume of data related to long-term traffic history, payload attribution systems (PASs) based on storing a compact digest of traffic using Bloom filters have been presented in the literature. In these systems, querying the stored digest for an excerpt results in a low number of suspects instead of certain criminals. In this...
Design and implementation of a stable platform digital controller based on DSP
, Article ICSES 2008 International Conference on Signals and Electronic Systems, ICSES'08, Krakow, 14 September 2008 through 17 September 2008 ; 2008 , Pages 453-456 ; 9788388309526 (ISBN) ; Chamani Takaldani, H. R ; Moosavienia, A ; Monfaredi, K ; Ebrahimi Atani, R ; Sharif University of Technology
2008
Abstract
The principle, configuration, and the special features of a stable platform digital controller are presented in this paper. The main goal of this paper is replacing an analog controller with its awaiting digital one. This has been done using TMS320LF2402 digital signal processor which offers the enhanced TMS320 DSP architectural design of the C2xx core CPU for low-cost, low-power, and high-performance processing capabilities. The experimental results show that the digital controller is identical to the analog one and can be a suitable replacement for the analog controller. Copyright © 2008 by Department of Electronics, AGH University of Science and Technology
Optimizing pipelines of trigonometric functions for FPGAs
, Article 2007 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, PACRIM, Victoria, BC, 22 August 2007 through 24 August 2007 ; 2007 , Pages 105-108 ; 1424411904 (ISBN); 9781424411900 (ISBN) ; Ebrahimi, H ; Sarbazi Azad, H ; Sharif University of Technology
2007
Abstract
Trigonometric functions are one of the most applicable functions in digital signal processing. In this paper, we propose two approaches for optimizing pipeline implementation of the CORDIC algorithm and compare it with other previous approaches. The proposed solutions are implemented on one of the Xilinx Virtex family's FPGAs. Our simulation results show that for high input bits, our approach is preferable to other existing approaches. ©2007 IEEE
A new pipeline implementation of an adaptive IIR filter for noise reduction application
, Article IEEE International Symposium on Communications and Information Technologies: Smart Info-Media Systems, ISCIT 2004, Sapporo, 26 October 2004 through 29 October 2004 ; Volume 1 , 2004 , Pages 577-581 ; 0780385934 (ISBN) ; Manzuri, M. T ; Ayat, S ; Sharif University of Technology
2004
Abstract
the parallel form in adaptive HR filtering is an efficient realization that provides robust stability monitoring with less complexity than that of the direct form. This paper presents an implementation of two line parallel structure employing a real orthogonal transform and real coefficients second-order section as sub filters on FPGA. Architecture that is implemented is in pipeline fashion and it is independent from its building blocks and they may have its own implementation or in other system numbering. In the last section, we compared throughput of our architecture with a Ti DSP (TMS320C3x/4x), the results show that this architecture works better than the DSP
Composite pnlms & nlms adaptation: A new method for network echo cancellation
, Article 14th International Conference on Digital Signal Processing, DSP 2002, 1 July 2002 through 3 July 2002 ; Volume 2 , 2002 , Pages 757-760 ; 0780375033 (ISBN) ; Atarodi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2002
Abstract
This paper describes an improved version of the recently proposed fast converging algorithm. PNLMS, for network echo cancellers. We have introduced a simple analysis of the PNLMS convergence behavior to show why after the fast initial convergence, it slows down. Also, the method has been worked out to overcome this deficiency is presented. Improvement is shown by several simulation results. © 2002 IEEE
Analysis of Digital DSP Blocks Using GDI Technology
, M.Sc. Thesis Sharif University of Technology ; Mortazavi, Mohammad (Supervisor)
Abstract
In line with developments in the technology of integrated circuits, transistors are implemented in silicon. Although the price is reduced; design is more complicated, which causes the efficiency and power consumption to face some difficulties in such design. The reason why modern GDI-based circuit is the focus of attention is that in designing a digital circuit, less power is required while more efficiency is obtained. Lowering the complexity of the logic circuit can bring about reduction of power consumption and propagation delay and decrease the circuit space. GDI-based integrated circuits resemble MOSFET transistors but have fewer transistors and higher performance capability. This study...
An image annotation rectifying method based on deep features
, Article 2nd International Conference on Digital Signal Processing, ICDSP 2018, 25 February 2018 through 27 February 2018 ; 2018 , Pages 88-92 ; 9781450364027 (ISBN) ; Jamzad, M ; Sharif University of Technology
Association for Computing Machinery
2018
Abstract
Automatic image annotation methods generate a list of tags for each test image and present it in a matrix structure. To achieve a more accurate annotation, we propose a method with the aim of correcting the tag list. In our method, we detect an indicator for each group of tags and use it to rectify the annotation results. To find a correct indicator, we apply a deep feature vector generated by the “AlexNet” model. Using this indicator, we determine the suitable tags for an image. The purposed method is independent of feature vector, dataset, and annotation method. It can be applied to the currently available annotation methods. Our experiments showed improvement in all annotation methods...
Higher-order statistical steganalysis of random LSB steganography
, Article 7th IEEE/ACS International Conference on Computer Systems and Applications, AICCSA-2009, Rabat, 10 May 2009 through 13 May 2009 ; 2009 , Pages 629-632 ; 9781424438068 (ISBN) ; Eghlidos, T ; Ghaemmaghami, S ; Sharif University of Technology
2009
Abstract
This paper presents a new scheme for steganalysis of random LSB embedding, capable of applying to any kind of digital signal in both spatial and transform domains. The proposed scheme is based on defining a space whose elements relate to higher-order statistical properties of the signal and looking for special subsets, which we call Closure of Sets (CoS) in this space. We use this scheme for steganalysis of the LSB steganography in grayscale images, employing a vector of five accurate and monotone features. Experimental results show significantly higher accuracy of the proposed scheme, as compared to those reported in the literature, especially in low embedding rates applications. © 2009...
Two channel abdominal PPG instrumentation
, Article IFMBE Proceedings ; Volume 21 IFMBE, Issue 1 , 2008 , Pages 691-693 ; 16800737 (ISSN); 9783540691389 (ISBN) ; Mohd Ali, M. A ; Zahedi, E ; Sharif University of Technology
Springer Verlag
2008
Abstract
In this paper, a two channel abdominal PPG instrumentation is developed. The proposed instrument consists of IR-LED and its driver, photo-detector and data acquisition card. The modulation frequency generation, demodulation and digital signal processing is done completely in the digital domain using LabView. The results show that the developed instrument is able to acquire signal from the abdomen even at 4 cm source to detector separation. This instrument is intended for future application in trans-abdominal fetal heart rate detection. © 2008 Springer-Verlag
The edge product of networks
, Article 18th International Conference on Parallel and Distributed Computing, Applications and Technologies, PDCAT 2007, Adelaide, SA, 3 December 2007 through 6 December 2007 ; January , 2007 , Pages 371-375 ; 0769530494 (ISBN); 9780769530499 (ISBN) ; Sarbazi Azad, H ; Sharif University of Technology
2007
Abstract
In this paper, a new graph product, called Edge Graph Product (EGP) is proposed by replacing each edge in the multiplicand graph by a copy of the multiplier graph via two candidate nodes. The edge product, unlike other products already proposed, results in a graph whose number of edges is numerical product of the number of the edges in the multiplicand and multiplier graphs, and the number of vertices is not equal to the numerical product of the number of vertices in the multiplicand and multiplier graphs. After formal definition of the new product, some basic properties of the product operator are studied. We then address Hamiltonian, Eulerian and routing properties of the new product, and...
Traffic improvements in wireless communication networks using antenna arrays
, Article IEEE Journal on Selected Areas in Communications, Piscataway, NJ, United States ; Volume 18, Issue 3 , 2000 , Pages 458-471 ; 07338716 (ISSN) ; Rashid Farrokhi, F ; Liu, K. J. R ; Sharif University of Technology
IEEE
2000
Abstract
A wireless network with beamforming capabilities at the receiver is considered that allows two or more transmitters to share the same channel to communicate with the base station. A novel approach is introduced, which combines the effects of the digital signal processing (adaptive beamforming) at the physical layer with the traffic policies at the network layer on the overall queuing model of a cell. The effect of signal processing on the queuing model of the cell is represented by a parameter in the final cell model. Each cell is modeled by a multiuser/multiserver service facility, where each server is a beamformed channel formed by the cell's base station. From this effective cell model,...
Compressive detection of sparse signals in additive white Gaussian noise without signal reconstruction
, Article Signal Processing ; Volume 131 , 2017 , Pages 376-385 ; 01651684 (ISSN) ; Babaie Zadeh, M ; Sharif University of Technology
Elsevier B.V
2017
Abstract
The main motivation behind compressive sensing is to reduce the sampling rate at the input of a digital signal processing system. However, if for processing the sensed signal one requires to reconstruct the corresponding Nyquist samples, then the data rate will be again high in the processing stages of the overall system. Therefore, it is preferred that the desired processing task is done directly on the compressive measurements, without the need for the reconstruction of the Nyquist samples. This paper addresses the case in which the processing task is “detection” (the existence) of a sparse signal in additive white Gaussian noise, with applications e.g. in radar systems. Moreover, we will...
Hybrid control of the dc-dc SRC operating below resonance
, Article IET Power Electronics ; Volume 10, Issue 1 , 2017 , Pages 1-9 ; 17554535 (ISSN) ; Tahami, F ; Molla Ahmadian, H ; Sharif University of Technology
Institution of Engineering and Technology
2017
Abstract
Control and stabilisation of the resonant converters are essential problems in power electronics. The conventional model of the dc-dc series resonant converter (SRC) is derived using the sinusoidal approximation and generalised averaging followed by linearisation about an operating point. This model involves considerable approximation and is not applicable for large variation of load and supply voltage. The authors have already proposed a direct piece-wise affine (DPWA) modelling and control approach for the SRC that operates above resonant frequency. However, the DPWA technique is not applicable to an SRC that operates below resonance because of the presence of harmonics. In this study, a...
Robust multiplicative patchwork method for audio watermarking
, Article DSP 2009:16th International Conference on Digital Signal Processing, Santorini, 5 July 2009 through 7 July 2009 ; 2009 ; 9781424432981 (ISBN) ; Akhaee, M. A ; Ahadi, M ; Amindavar, H. R ; Sharif University of Technology
2009
Abstract
A Multiplicative Patchwork Method (MPM) for audio watermarking is proposed in this paper. In order to embed watermark data within the host signal, two subsets of the host signal features are selected using two secret keys. Then, watermark data is inserted simply by multiplying one subset and leaving the other one unchanged. In order to have an error free detection in attack-free case, embedding is performed in the selected frames of the host signal which satisfies a certain condition. This method is implemented in the wavelet domain and approximation coefficients are used for data embedding. Furthermore, the inaudibility of watermark insertion is controlled using iterative approach aided by...
An efficient SRAM-Based reconfigurable architecture for embedded processors
, Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems ; Volume 38, Issue 3 , 2019 , Pages 466-479 ; 02780070 (ISSN) ; Ebrahimi, Z ; Khaleghi, B ; Asadi, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Nowadays, embedded processors are widely used in wide range of domains from low-power to safety-critical applications. By providing prominent features such as variant peripheral support and flexibility to partial or major design modifications, field-programmable gate arrays (FPGAs) are commonly used to implement either an entire embedded system or a hardware description language-based processor, known as soft-core processor. FPGA-based designs, however, suffer from high power consumption, large die area, and low performance that hinders common use of soft-core processors in low-power embedded systems. In this paper, we present an efficient reconfigurable architecture to implement soft-core...
Real-Time Processing of Electrical Impedance Tomography Signals Using DSP
, M.Sc. Thesis Sharif University of Technology ; Vosoughi Vahdat, Bijan (Supervisor)
Abstract
Block Method approach solving Forward Problem in Electrical Impedance Tomography (EIT) results exact solution if the measurements are done with enough accuracy. Solving Forward problem with this method brings complexity to required calculations and sufficient speed is needed to extract required data in minimum time. In this thesis, 3D model of EIT with Block Method is implemented by means of Digital Signal Processor (DSP) to obtain maximum speed. Program code is written both in MATLAB and Code Composer Studio in efficient way to decrease clock cycles of CPU. Moreover, some part of algorithm is modified and the desired speed is obtained. At the end, two kinds of DSP, Fixed-point (TMS320C6416)...
Efficient Implementation of MPEG-4 HE-AACv2 on a Fixed-Point DSP
, M.Sc. Thesis Sharif University of Technology ; Haj Sadeghi, Khosro (Supervisor)
Abstract
Providing multimedia content to the end-user is one of the most challenging tasks in today’s digital world. Therefore choosing the best media compression method is both technically and economically important. In the context of audio codecs, MPEG-4 HE-AACv2 is capable of providing very high quality output at very low bitrates. 3GPP Enhanced aacPlus is one of the practical implementations of this codec, which is extensively adopted by several telecommunication standards as the main audio compression algorithm.
Nowadays almost every cell phone and portable digital media player includes a DSP. The C6000 family of DSPs from Texas Instruments has been exploited for the purpose of this...
Nowadays almost every cell phone and portable digital media player includes a DSP. The C6000 family of DSPs from Texas Instruments has been exploited for the purpose of this...
Designing a System for Pulse Pile-Up Processing in Gamma Ray Spectroscopy Based on Digital Method
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Abolfazl (Supervisor)
Abstract
In Radiation Detection Systems applied in Spectroscopy and Imaging, if the rate of particle incidence with detector is high, the output pulses being stacked up on each other will be expected, which is known as “Pulse Pile-up”. Pulse pile-up might result in a serious disorder of energy and timing data expected from the pulses. In recent decades and after successful implementation of pile-up rejection methods on analog circuits, considering development and progression in the field of digital, different algorithms based on pileup correction methods have been developed to obtain all spectrum information, whether energy, rise time and recorded pulses. Such methods can be compared in different...