Random time delay problem is a key problem in networked control systems（NCSs） and uncertain metrology delay *** from the ordinary delay,the random delay is usually described in time *** this paper,a Laplace transfor...
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ISBN:
(纸本)9781538629185
Random time delay problem is a key problem in networked control systems（NCSs） and uncertain metrology delay *** from the ordinary delay,the random delay is usually described in time *** this paper,a Laplace transform strategy is used to analyze random time delay ***,the various Laplace transforms of random variables are discussed;then,based on the output response expectation equivalent principle,the appropriate Laplace transform for random delay is *** use the Laplace transform,the random time delay can be discussed in frequency *** particular,some difficult random delay problem in the time domain can be very simple to solve in the frequency ***,simulations are given to verify the proposed strategy of this paper and some interesting results has been obtained.
In this paper, we apply a scaling analysis of the maximum of the probability density function（pdf） of velocity increments, i.e., max（） = max（）up p u, for a velocity field of turbulent Rayleigh-Bénard convec...
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In this paper, we apply a scaling analysis of the maximum of the probability density function（pdf） of velocity increments, i.e., max（） = max（）up p u, for a velocity field of turbulent Rayleigh-Bénard convection obtained at the Taylor-microscale Reynolds number Re60. The scaling exponent is comparable with that of the first-order velocity structure function, （1）, in which the large-scale effect might be constrained, showing the background fluctuations of the velocity field. It is found that the integral time T（x/ D） scales as T（x/ D）（x/ D）, with a scaling exponent =0.25 0.01, suggesting the large-scale inhomogeneity of the flow. Moreover, the pdf scaling exponent （x, z） is strongly inhomogeneous in the x（horizontal） direction. The vertical-direction-averaged pdf scaling exponent （x） obeys a logarithm law with respect to x, the distance from the cell sidewall, with a scaling exponent 0.22 within the velocity boundary layer and 0.28 near the cell sidewall. In the cell＇s central region, （x, z） fluctuates around 0.37, which agrees well with （1） obtained in high-Reynolds-number turbulent flows, implying the same intermittent correction. Moreover, the length of the inertial range represented in decade（）IT x is found to be linearly increasing with the wall distance x with an exponent 0.65 0.05.
In order to monitor the water quality widely and rapidly in The Three Gorges zone,it’s useful to gain the information in real-time by remote sensing images,but there are some defects in remote sensing images,such as ...
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In order to monitor the water quality widely and rapidly in The Three Gorges zone,it’s useful to gain the information in real-time by remote sensing images,but there are some defects in remote sensing images,such as bad visual contrast,low-resolution,and low *** than general optical images,remote sensing images contain a large amount of information;its processing is time *** order to improve the contrast and details of the image and reduce the complication of compute,an image enhancement approach based on wavelet and histogram specification is proposed in this *** the experiment results and comparison with the original image,we can see that the contrast improved by about 200%and information entropy improved by about 107%.Our proposed algorithm not only enhances the details of image greatly,but also preserves the color information of original remote sensing image *** this method do not convert the color image to other color space,the computation complexity is simple,so it is an efficient algorithm for remote sensing image enhancement in real-time.
A new fault tolerant control（FTC） via a controller reconfiguration approach for general stochastic nonlinear systems is *** from the formulation of classical FTC methods,it is supposed that the measured information ...
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A new fault tolerant control（FTC） via a controller reconfiguration approach for general stochastic nonlinear systems is *** from the formulation of classical FTC methods,it is supposed that the measured information for the FTC is the probabilitydensityfunctions（pdfs） of the system output rather than its measured value.A radial basis functions（RBFs） neural network technique is proposed so that the output pdfs can be formulated in terms of the dynamic weighings of the RBFs neural *** a result,the nonlinear FTC problem subject to dynamic relation between the input and the output pdfs can be transformed into a nonlinear FTC problem subject to dynamic relation between the control input and the weights of the RBFs neural network approximation to the output *** FTC design consists of two *** first step is fault detection and diagnosis（FDD）,which can produce an alarm when there is a fault in the system and also locate which component has a *** second step is to adapt the controller to the faulty case so that the system is able to achieve its target.A linear matrix inequality（LMI） based feasible FTC method is applied such that the fault can be detected and *** illustrated example is included to demonstrate the efficiency of the proposed algorithm,and satisfactory results have been obtained.
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