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Further improvement in the control accuracy of the hydraulic servo system is hampered by its position control structure and non-structural uncertainty. For structural uncertainties, nonlinear adaptive control can be applied to achieve asymptotic tracking performance. While unstructured uncertainties, such as nonlinear frictions, always exist in hydraulic systems and reduce the tracking accuracy. In...
The research of failure analysis for integrated circuits can improve the reliability. Based on one failed circuit, do the analysis which including eletrical parameter test, chip surface check, schematic diagram and layout analysis, and find the failure reason, then use simulation to verify the analized conclusion. Finally, throw out some effective ways to avoid this kind of failure that might happen...
Generators are the key equipment to determine the characteristics of power system dynamic behavior, the accuracy of generators' mathematical model and parameters will directly affect the results of power system dynamic simulation. Therefore, it is particularly important to assess the accuracy of generators' simulation model. In this paper, accuracy indices were proposed to evaluate the generator dynamic...
In this paper, the hyperbolic S-transform (HS-transform) has been generalized with the introduction of the whole time frequency regulation factor and the regulation of frequency in the HS window function. Combined with the idea of incomplete S-transform, a rapid harmonic detection based on generalized HS-transform (GHST) is proposed. Firstly, it detected each harmonic frequency according to the dynamic...
This paper is concerned with the solution of unsteady incompressible flow problems using Marker and Cell finite difference discretizations and preconditioned Krylov subspace methods. Our emphasis is on the preconditioner that can be thought of a new splitting of the discretized equations. The preconditioner we focus on is the variation from the Hermitian and Skew-Hermitian (HSS) Splitting preconditioner...
Image matting is an important task in image and video editing. In this paper we propose a novel interactive matting system. Starting from a coarse user-guided trimap, we first perform a texture-based background estimation, and use the result to refine the original trimap. Then we apply soft matting process with new trimap and allow the user to refine the result by directly touching up the opacity...
Image categorization is an important issue in computer vision. The bag-of-visual words(BOV) model which ignores spatial restriction of local features has gained state-of-the-art performance in recent years. The basic BOV model uses k-means to form codebook. As sparse codes can better represent local features, we use sparse codes of SIFT features instead of k-means to form codebook. Additional, as...
Image matting is the problem of softly and accurately extracting the foreground from a natural digital image. Matting is inherently an ill-posed problem. Most previous methods use user-defined trimap as additional constraints. Given a trimap, a simple way to compute the alpha value is to select some known foreground and background colors for each unknown pixel. Existing sampling-based matting methods...
Image matting is an important task in image and video editing. In this paper we propose a novel matting system, which can provide good results with less human intervention. We split the task into two steps: attention-based scribble extraction followed by alpha matting. We use the attention shift trace which is refined in the HSI color space as the useful constraints for matting algorithm instead of...
In computer vision, the bag-of-visual words(BOV) approach has been shown to yield state-of-the-art results. To improve BOV model, we use sparse codes of SIFT features instead of previous vector quantization (VQ) such as k-means, due to more quantization errors of VQ. And as local features in most categories have spatial dependence in real world, we use neighbor features of one local feature as its...
The analysis and evaluation of urban passenger traffic structure (UPTS) is necessary for achieving urban traffic development decision scientifically and improving urban traffic system efficiency. After analyzing the characteristics of various traffic modes, a general ecological adaptability evaluation (EAE) model for UPTS was proposed. This model mainly referred to three aspects, for instance, vehicle...
Signal control plays an importing role on resolving traffic jam on big roundabout. This paper analyzes signal control methods and characteristics on roundabout home and abroad. The characteristics of signal control and non-signal control on the roundabout were analyzed by comparison. Further more, it was introduced to discuss signal control methods on roundabout, emphasize the principle, steps and...
This paper investigates the design and application of a sliding mode observer (SMO) strategy for fault detection problem for satellite attitude control systems. A particular design of sliding mode observer is presented for which the parameters can be obtained by a linear change of coordinates under some conditions. Instead of generating residuals for other observer-based fault detection methods, the...
The bag-of-words approach is gained much research in object categorization. Creating visual codebook is an important problem in object categorization. The non-informative codeword will increase the vocabulary size which brings more computation cost, and cannot improve the classification performance. We first define a weighted minimal-redundancy-maximal-relevance criterion (mRMR) which is an extension...
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