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adaptive-processing
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Towards a self-adaptive service-oriented methodology based on extended SOMA
, Article Frontiers of Information Technology & Electronic Engineering ; Volume 16, Issue 1 , January 2015 , Pages 43-69 ; Moaven, S ; Habibi, J ; Beigi, G ; Naser-Shariat, M ; Sharif University of Technology
Abstract
We propose a self-adaptive process (SAP) that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-oriented methodologies due to its explicitly defined inputs and outputs. To this aim, the proposed SAP is integrated with the service-oriented modeling and application (SOMA) methodology in a two-layered structure to create a novel methodology, named self-adaptive service-oriented architecture methodology (SASOAM), which provides a semi-automatic self-aware method by the composition of architectural tactics. Moreover, the maintenance activity of SOMA is improved using...
Some nonlinear/adaptive methods for fast recovery of the missing samples of signals
, Article Signal Processing ; Volume 88, Issue 3 , 2008 , Pages 624-638 ; 01651684 (ISSN) ; Jahani Yekta, M. M ; Marvasti, F ; Sharif University of Technology
2008
Abstract
In this paper an iterative method for recovery of the missing samples of signals is investigated in detail, and some novel linear, nonlinear, and adaptive extrapolation techniques are proposed to be used along with it to increase the convergence rate of the recovery system. The proposed methods would remarkably speed up the convergence rate, save processing power, and reduce the delay of the system compared to some well known accelerated versions of the aforementioned iterative algorithm. © 2007 Elsevier B.V. All rights reserved
Towards a self-adaptive service-oriented methodology based on extended SOMA
, Article Journal of Zhejiang University: Science C ; Volume 16, Issue 1 , 2015 , Pages 43-69 ; 18691951 (ISSN) ; Moaven, S ; Habibi, J ; Beigi, G ; Naser Shariat, M ; Sharif University of Technology
Abstract
We propose a self-adaptive process (SAP) that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-oriented methodologies due to its explicitly defined inputs and outputs. To this aim, the proposed SAP is integrated with the service-oriented modeling and application (SOMA) methodology in a two-layered structure to create a novel methodology, named self-adaptive service-oriented architecture methodology (SASOAM), which provides a semi-automatic self-aware method by the composition of architectural tactics. Moreover, the maintenance activity of SOMA is improved using...
Towards a self-adaptive service-oriented methodology based on extended SOMA
, Article Frontiers of Information Technology and Electronic Engineering ; Volume 16, Issue 1 , 2015 , Pages 43-69 ; 20959184 (ISSN) ; Moaven, S ; Habibi, J ; Beigi, G ; Naser Shariat, M ; Sharif University of Technology
Abstract
We propose a self-adaptive process (SAP) that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-oriented methodologies due to its explicitly defined inputs and outputs. To this aim, the proposed SAP is integrated with the service-oriented modeling and application (SOMA) methodology in a two-layered structure to create a novel methodology, named self-adaptive service-oriented architecture methodology (SASOAM), which provides a semi-automatic self-aware method by the composition of architectural tactics. Moreover, the maintenance activity of SOMA is improved using...
Rate-maximizing adaptation in multiantenna OFDM systems with space-time-frequency coding
, Article 2006 IEEE International Conference on Communications, ICC 2006, Istanbul, 11 July 2006 through 15 July 2006 ; Volume 6 , 2006 , Pages 2905-2910 ; 05361486 (ISSN); 1424403553 (ISBN); 9781424403554 (ISBN) ; Khalaj, B. H ; Sharif University of Technology
2006
Abstract
In this paper, we first propose a space-time-frequency (STF) coding method for multiple-input multiple-output orthogonal frequency division multiplexing (MIMOOFDM) transmission over frequency-selective fading channels and then, based on channel mean feedback model, we develop an adaptive MIMO-OFDM transmitter by applying an adaptive energy and bit loading scheme across OFDM subcarriers. Under the constraints of fixed transmit-energy and prescribed error performance, our objective is to maximize the transmission rate. Simulation results are presented which confirm the performance of our proposed system and show that under certain circumstances, the transmission rate improves considerably as...
Ground Clutter Cancellation in Airborne Radar
, M.Sc. Thesis Sharif University of Technology ; Behnia, Fereidoon (Supervisor)
Abstract
Space-time adaptive processing (STAP) is one of the powerful algorithms for clutter suppression in airborne radars. In this algorithm, we need to estimate the covariance matrix of the range bin under test, exploiting adjacent range bins. Thus it is important for clutter to have the same space-time characteristics in different range bins; otherwise degradation will occur in clutter suppression. Therefore, traditional STAP is desired to be discussed in the side-looking mode in which clutters are range independent. In some situations, we need to employ STAP in the non-side-looking geometries of the arrays. For instance, sometimes it is needed to rotate the array to gain better coverage of...
Abnormal event detection and localisation in traffic videos based on group sparse topical coding
, Article IET Image Processing ; Volume 10, Issue 3 , 2016 , Pages 235-246 ; 17519659 (ISSN) ; Tabandeh, M ; Gholampour, I ; Sharif University of Technology
Institution of Engineering and Technology
2016
Abstract
In visual surveillance, detecting and localising abnormal events are of great interest. In this study, an unsupervised method is proposed to automatically discover abnormal events occurring in traffic videos. For learning typical motion patterns occurring in such videos, a group sparse topical coding (GSTC) framework and an improved version of it are applied to optical flow features extracted from video clips. Then a very simple and efficient algorithm is proposed for GSTC. It is shown that discovered motion patterns can be employed directly in detecting abnormal events. A variety of abnormality metrics based on the resulting sparse codes for detection of abnormality are investigated....
2-D spectral estimation in CW forward scatter radars
, Article Proceedings International Radar Symposium, 24 June 2015 through 26 June 2015 ; Volume 2015-August , 2015 , Pages 664-669 ; 21555753 (ISSN); 9783954048533 (ISBN); 9783954048533 (ISBN); 9783954048533 (ISBN) ; Bagheri, A. M ; Azarbar, A ; Nayebi, M. M ; Rohling H ; Rohling H ; Rohling H ; Sharif University of Technology
IEEE Computer Society
2015
Abstract
In CW forward scatter radars, Space-Time processing by 2-D FFT is used to estimate Doppler frequency shift and angle of arrival concurrently. 2-D periodogram and 2-D Capon methods are two famous spectral estimation methods which can be substituted for 2-D FFT. Here we will provide analysis of performance for these methods beside their cons and pros
Optimal MIMO waveform design with controlled characteristics
, Article Proceedings International Radar Symposium, 24 June 2015 through 26 June 2015 ; Volume 2015-August , 2015 , Pages 1141-1146 ; 21555753 (ISSN) ; 9783954048533 (ISBN); 9783954048533 (ISBN); 9783954048533 (ISBN) ; Radmard, M ; Nayebi, M. M ; Bastani, M. H ; Rohling, H ; Rohling, H ; Rohling, H ; Sharif University of Technology
IEEE Computer Society
2015
Abstract
In a MIMO (Multiple Input Multiple Output) radar system, proper design of transmit signal and receive filter is an advantageous tool to improve the detection performance. Thus, in this paper, we consider the problem of transmit code and receive filter design, in order to maximize the Signal to Noise Ratio (SNR) at the receiver while enforcing a similarity constraint between the transmit space-time code (STC) and a reference STC which has a desirable ambiguity function. We will show that by solving such constrained optimization problem through successive iterations, our proposed method leads to satisfactory results
Fast maximum-likelihood decoder for quasi-orthogonal space-time block code
, Article Mathematical Problems in Engineering ; Volume 2015 , 2015 ; 1024123X (ISSN) ; Talebi, S ; Sharif University of Technology
Hindawi Publishing Corporation
2015
Abstract
Motivated by the decompositions of sphere and QR-based methods, in this paper we present an extremely fast maximum-likelihood (ML) detection approach for quasi-orthogonal space-time block code (QOSTBC). The proposed algorithm with a relatively simple design exploits structure of quadrature amplitude modulation (QAM) constellations to achieve its goal and can be extended to any arbitrary constellation. Our decoder utilizes a new decomposition technique for ML metric which divides the metric into independent positive parts and a positive interference part. Search spaces of symbols are substantially reduced by employing the independent parts and statistics of noise. Symbols within the search...
A new approach to fast decode quasi-orthogonal space-time block codes
, Article IEEE Transactions on Wireless Communications ; Volume 14, Issue 1 , 2015 , Pages 165-176 ; 15361276 (ISSN) ; Talebi, S ; Shahabinejad, M ; Sharif University of Technology
Abstract
Motivated by the statistical correspondence between phases of the transmitted and received vectors, we present a fast decoding method for quasi-orthogonal space-time block codes (QOSTBCs) in this paper. The proposed decoder selects proper candidates from precomputed and sorted sets by focusing on the phase of a specific entry of the combined and decoupled vector. The ML metric of the most probable candidates is first evaluated, and then, the remaining candidates are assessed based on the similarity between the phases. The new algorithm can work with any type of constellation such as QAM and PSK and supports generalized block-diagonal QOSTBCs. Theoretical results backed by simulation tests...
Beyond bag-of-words: An improved Sparse Topical Coding for learning motion patterns in traffic scenes
, Article 9th Iranian Conference on Machine Vision and Image Processing, 18 November 2015 through 19 November 2015 ; Volume 2016-February , 2015 , Pages 1-4 ; 21666776 (ISSN) ; 9781467385398 (ISBN) ; Tabandeh, M ; Gholampour, I ; Sharif University of Technology
IEEE Computer Society
Abstract
Analyzing motion patterns in traffic videos can directly generate some high-level descriptions of the video content which can be further employed in rule mining and abnormal event detection. The most recent and successful unsupervised approaches for complex traffic scene analysis are based on topic models. However, most existing topic models share some key characteristics which could limit their utility. In this paper, based on extracted optical flow features from video clips, we employ Sparse Topical Coding (STC) framework to automatically discover typical motion patterns in traffic scenes. For this purpose, we improve the STC to overcome one of the drawbacks of topic models with the aim of...
Two quasi orthogonal space-time block codes with better performance and low complexity decoder
, Article 10th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2016, 20 July 2016 through 23 July 2016 ; 2016 ; 9781509025268 (ISBN) ; Talebi, S ; Chizari, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
This paper presents two new space time block codes (STBCs) with quasi orthogonal structure for an open loop multi-input single-output (MISO) systems. These two codes have been designed to transmit from three or four antennas at the transmitter and be given to one antenna at the receiver. In this paper first, the proposed codes are introduced and their structures are investigated. This is followed by the demonstration of how the decoder decodes half of transmitted symbols independent of the other half. The last part of this paper discusses the simulation results, makes performance comparison against other popular approaches and concludes that the proposed solutions offer superiority
Cooperative transmission for wireless relay networks using limited feedback
, Article IEEE Transactions on Signal Processing ; Volume 58, Issue 7 , Jun , 2010 , Pages 3828-3841 ; 1053587X (ISSN) ; Khalaj, B. H ; Gershman, A. B ; Sharif University of Technology
2010
Abstract
To achieve the available performance gains in half-duplex wireless relay networks, several cooperative schemes have been earlier proposed using either distributed space-time coding or distributed beamforming for the transmitter without and with channel state information (CSI), respectively. However, these schemes typically have rather high implementation and/or decoding complexities, especially when the number of relays is high. In this paper, we propose a simple low-rate feedback-based approach to achieve maximum diversity with a low decoding and implementation complexity. To further improve the performance of the proposed scheme, the knowledge of the second-order channel statistics is...