signalprocessing hardware and software that can be used to improve the detection of certain power system faults using computer relays are discussed. Integrated systems and architectures for monitoring several fault-s...
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signalprocessing hardware and software that can be used to improve the detection of certain power system faults using computer relays are discussed. Integrated systems and architectures for monitoring several fault-sensitive parameters have been investigated. A suggested architecture utilizing several processors is presented. Several fault-sensitive parameters for the detection of arcing faults are presented. A detection methodology based on these parameters is described, and a partial solution to the problem of directionality is discussed. The use of a knowledge-based environment to modify protection criteria is suggested.< >
What should we do to raise the quality of signalprocessing publications to an even higher level? We believe it to be crucial to maintain the precision in describing our work in publications, ensured through a high-qu...
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What should we do to raise the quality of signalprocessing publications to an even higher level? We believe it to be crucial to maintain the precision in describing our work in publications, ensured through a high-quality reviewing process. We also believe that if the experiments are performed on a large data set, the algorithm is compared to the state-of-the-art methods, the code and/or data are well documented and available online, we will all benefit and make it easier to build upon each other's work. It is a clear win-win situation for our community: we will have access to more and more algorithms and can spend time inventing new things rather than recreating existing ones.
In [1], we described a class of fast subspace decomposition (FSD) algorithms. Though these algorithms can be applied to solve a variety of signalprocessing and communication problems with significant computational re...
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In [1], we described a class of fast subspace decomposition (FSD) algorithms. Though these algorithms can be applied to solve a variety of signalprocessing and communication problems with significant computational reduction, we shall focus our discussion on two typical applications. i.e., sensor array processing and time series analysis. In many cases, replacing usual eigenvalue decomposition (EVD) or singular value decomposition (SVD) by FSD is quite straightforward. However, the FSD approach can exploit more structure of some special problems to further simplify the implementation. In this paper, we shall first discuss the implementation details of FSD such as how to choose an optimal starting vector, how to handle correlated noise, and how to exploit additional matrix structure for further computational reduction. Then, we describe an FSD approach targeted at data matrices (rectangular N x M, N greater-than-or-equal-to M), which requires only O(NMd) flops where d denotes the signal subspace dimension versus a regular O(N M2 + M3) SVD. The computational reduction is substantial in tropical scenarios d much less than M less-than-or-equal-to N. In the spectrum estimation problems, the data matrix has additional structure such as Toeplitz or Hankel, we shall finally show how FSD can exploit such structure for further computational reduction.
The application of two-dimensional (2-D) signalprocessing to data collected in airborne laser bathymetry is investigated. Specifically, a type of 2-D filter for the suppression of impulsive noise in irregularly-space...
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The application of two-dimensional (2-D) signalprocessing to data collected in airborne laser bathymetry is investigated. Specifically, a type of 2-D filter for the suppression of impulsive noise in irregularly-spaced data based on order-statistics filtering is developed. An algorithm which incorporates this type of filter along with a sophisticated 2-D interpolation technique is constructed to automate the filtering process. An adaptive 2-D filtering technique that can be applied to raw bathymetric profiles to remove wideband noise is then discussed. The results obtained show that each type of filtering enhances the accuracy of bathymetric measurement quite significantly.
A general criterion for the design of adaptive systems in digital communications called the statistical reference criterion is proposed. The criterion is based on imposition of the probability density function of the ...
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A general criterion for the design of adaptive systems in digital communications called the statistical reference criterion is proposed. The criterion is based on imposition of the probability density function of the signal of interest at the output of the adaptive system, with its application to the scenario of highly powerful interferers being the main focus of this paper, The knowledge of the pdf of the wanted signal is used as a discriminator between signals so that interferers with differing distributions are rejected by the algorithm, Its performance is studied over a range of scenarios, Equations for gradient-based coefficient updates are derived, and the relationship with other existing algorithms like the minimum variance and the Wiener criterion are examined.
The rapid and objective measurement of timing intervals of the electrocardiogram (ECG) by automated systems is superior to the subjective assessment of ECG morphology. The timing interval measurements are usually made...
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The rapid and objective measurement of timing intervals of the electrocardiogram (ECG) by automated systems is superior to the subjective assessment of ECG morphology. The timing interval measurements are usually made from the onset to the termination of any component of the EGG, after accurate detection of the QRS complex. This article describes a real-time system that uses wavelet transforms to overcome the limitations of other methods of detecting QRS and the onsets and offsets of P- and T-waves. Wavelet transformation is briefly discussed, and detection methods and hardware and software aspects of the system are presented, as well as experimental results.
In many cases, observed brain signals can be assumed as the linear mixtures of unknown brain sources/components. It is the task of blind source separation (BSS) to find the sources. However, the number of brain source...
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In many cases, observed brain signals can be assumed as the linear mixtures of unknown brain sources/components. It is the task of blind source separation (BSS) to find the sources. However, the number of brain sources is generally larger than the number of mixtures, which leads to an underdetermined model with infinite solutions. Under the reasonable assumption that brain sources are sparse within a domain, e.g., in the spatial, time, or time-frequency domain, we may obtain the sources through sparse representation. As explained in this article, several other typical problems, e.g., feature selection in brain signalprocessing, can also be formulated as the underdetermined linear model and solved by sparse representation. This article first reviews the probabilistic results of the equivalence between two important sparse solutions?the 0-norm and 1-norm solutions. In sparse representation-based brain component analysis including blind separation of brain sources and electroencephalogram (EEG) inverse imaging, the equivalence is related to the recoverability of the sources. This article also focuses on the applications of sparse representation in brain signalprocessing, including components extraction, BSS and EEG inverse imaging, feature selection, and classification. Based on functional magnetic resonance imaging (fMRI) and EEG data, the corresponding methods and experimental results are reviewed.
This article is devoted to the polynomial eigenvalue decomposition (PEVD) and its applications in broadband multichannel signalprocessing, motivated by the optimum solutions provided by the EVD for the narrowband cas...
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This article is devoted to the polynomial eigenvalue decomposition (PEVD) and its applications in broadband multichannel signalprocessing, motivated by the optimum solutions provided by the EVD for the narrowband case [1], [2]. In general, we would like to extend the utility of the EVD to also address broadband problems. Multichannel broadband signals arise at the core of many essential commercial applications, such as telecommunications, speech processing, health-care monitoring, astronomy and seismic surveillance, and military technologies, including radar, sonar, and communications [3]. The success of these applications often depends on the performance of signalprocessing tasks, including data compression [4], source localization [5], channel coding [6], signal enhancement [7], beamforming [8], and source separation [9]. In most cases and for narrowband signals, performing an EVD is the key to the signalprocessing algorithm. Therefore, this article aims to introduce the PEVD as a novel mathematical technique suitable for many broadband signalprocessing applications.
Phase retrieval refers to the problem of recovering a high-dimensional vector ${\mathbf{x}} \in {\mathbb{C}^N}$ from the magnitude of its linear transform z = Ax, observed through a noisy channel. To improve the ill-p...
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ISBN:
(数字)9798350368741
ISBN:
(纸本)9798350368758
Phase retrieval refers to the problem of recovering a high-dimensional vector ${\mathbf{x}} \in {\mathbb{C}^N}$ from the magnitude of its linear transform z = Ax, observed through a noisy channel. To improve the ill-posed nature of the inverse problem, it is a common practice to observe the magnitude of linear measurements z (1) = A (1) x,…, z (L) = A (L) x using multiple sensing matrices A (1) ,…, A (L) , with ptychographic imaging being a remarkable example of such strategies. Inspired by existing algorithms for ptychographic reconstruction, we introduce stochasticity to Vector Approximate Message Passing (VAMP), a computationally efficient algorithm applicable to a wide range of Bayesian inverse problems. By testing our approach in the setup of phase retrieval, we show the superior convergence speed of the proposed algorithm.
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