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1 IntroductionMultiresolutionsignalprocessingisbecomingmorepopularincommunicationandinformationpro cessingfieldsbecauseofitsfineproperty ,especiallyinimagecoding .Itsplitsasignalintoseveralsub bandsignalswithdifferentbandwidthstoutilizethecharacterdiffe…  相似文献   

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Particle filter has been proven very robust in handling non-linear and non-Gaussian problems and has been widely used in the area of object tracking. One of the main problems in particle filter-based object tracking is, however, its high computational cost induced by the most time-consuming stage of measurement model computation. This paper makes progress in resolving the problem by proposing an efficient particle filter-based tracking algorithm using color information. First, a compact color cooccurrence histogram is presented, which considers both spatial and color information and can effectively represent color distribution with a very small number of histogram bins. The paper also introduces integral images by which the cooccurrence histogram can be obtained with simple array reference operations. However, the construction of the integral images on the CPU may be computationally expensive. Hence, this paper develops parallel algorithms on a desktop Graphics Processing Unit (GPU), which accomplishes the integral images construction and cooccurrence histogram computation after bin index determination. The resulting algorithm is quite efficient and has better performance than the traditional histogram-based tracking algorithm. The tracking time of the proposed algorithm increases insignificantly with the growth of particle number, and it remains consistent among varying image sequences and stable throughout all frames in the same image sequence due to its irrelevance to object size. Experiments in diverse image sequences validate our conclusions.  相似文献   

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Journal of Communications Technology and Electronics - A method for synthesis of Gordon–Mills–Welch sequences (GMWSs) over extended field GF[(2m)n], based on the relationship of the...  相似文献   

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Journal of Communications Technology and Electronics - The problem of creating an acousto-optic (AO) tunable filter, which allows us to obtain high-quality spectral images both in the visible and...  相似文献   

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This paper is concerned with the problem of robust l 2l filter design for a class of uncertain switched time-delay systems based on a switched Lyapunov functional. The parametric uncertainties are assumed to be time varying but norm bounded. The purpose is to design a switched filter such that, for all admissible uncertainties, the resulting filtering error system is robustly stable and satisfies a prescribed l 2l performance level. By introducing some extra matrices, a desired filter can be constructed by solving certain linear matrix inequalities (LMIs). A numerical example is given to demonstrate the effectiveness of the proposed method.  相似文献   

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Attenuating the noises plays an essential role in the image processing. Almost all the traditional median filters concern the removal of impulse noise having a single layer, whose noise gray level value is constant. In this paper, a new adaptive median filter is proposed to handle those images corrupted not only by single layer noise. The adaptive threshold median filter (ATMF) has been developed by combining the adaptive median filter (AMF) and two dynamic thresholds. Because of the dynamic threshold being used, the ATMF is able to balance the removal of the multiple-impulse noise and the quality of image. Comparison of the proposed method with traditional median filters is provided. Some visual examples are given to demonstrate the performance of the proposed filter.  相似文献   

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By using Walsh matrix,a new method of parameter identification is proposed,and then an example is given.  相似文献   

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NewMethodofParameterIdentificationbyUsingWalshMatrix①YAOLingshi(YanshanUniversity,Qinhuangdao066004,CHN)Abstract:ByusingWalsh...  相似文献   

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Multidimensional Systems and Signal Processing - We prove that through the analysis of the static, nonlinear system output to an exponential sweep excitation, it is possible to make an easy and...  相似文献   

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Advances in developing transitions in microwave integrated circuits during the last ten years are reviewed. Some typical structures of transition are introduced, Transition structures can be classified into two basic types: one is transition between the same ]rind of transmission lines on different planes of a common substrate, the other transition between different types of transmission lines.Furthermore, future development of transition structures is discussed.  相似文献   

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Uncertain components in the integrators of 2–1 Sigma–Delta modulators cannot eliminate the first stage quantization noise completely, and the signal-to-noise ratio in analogue-to-digital converters is not reduced perfectly either. In order to solve the matching problem, older filter designs based on convex optimization are mathematically complicated, computationally intensive and not so efficient in application. In this paper, we propose a design method based on curve fitting approximation for uncertain linearized model of the modulator which is simple in principle and practical in application. Simulation results show that the optimal filter has better performance on multiple validations when compared to other modulator filters.  相似文献   

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A novel, camera-based method for direct implied open-circuit voltage (iVOC) imaging via the use of a single bandpass filter (s-BPF) is developed for large-area photovoltaic solar cells and precursors. The photoluminescence (PL) emission is imaged using a narrow BPF with centre energy inside the high-energy tail of the PL emission, utilising the close-to-unity and nearly constant absorptivity of typical photovoltaic devices in this energy range. As a result, the exact value of the sample's absorptivity within the BPF transmission band is not required. The use of an s-BPF enables a fully contactless approach to calibrate the absolute PL photon flux for spectrally integrated detectors, including cameras. The method eliminates the need for knowledge of the imaging system spectral response. Through an appropriate choice of the BPF centre energy, a range of absorber compositions or a single absorber with different surface morphologies, such as planar and textured, can be imaged, all without the need for additional detection optics. The feasibility of this s-BPF method is first validated. The relative error in iVOC is determined to be ≤1.5%. The method is then demonstrated on device stacks with two different perovskite compositions commonly used in single-junction and monolithic tandem solar cells.  相似文献   

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The past few years have witnessed significant development in the controlled growth of 2D heterostructures. Among those kinds of heterostructures, vertical and lateral ones have drawn the most attention. Vertical heterostructures can be created in the mode of layer by layer. The layer number and sequence in the vertical orientation can be modulated and thus leading to customized properties. However, the fabrication of lateral heterostructures has been met with challenges. The most concerning issue is related to the consistency at the atomic scale when two layers are stitched in a lateral direction. Adhering to the concept of epitaxial growth, chemical vapor deposition (CVD) has exerted significant impact in forming 2D lateral heterostructures. In this review, recent academic breakthroughs involving controlled growth of multi-heterostructures by CVD are present. The CVD technique in terms of growth parameters, choice of catalysts, and mechanism is fully emphasized, offering guidelines for shaping novel 2D heterostructures. Several novel multi-heterostructures attained by the CVD method are exhibited. Further, the properties and devices are described to demonstrate the unique features of multi-heterostructures. The great advances in precisely constructing multi-heterostructure are expected to push forward the way for 2D materials to industrialization and commercialization.  相似文献   

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The paper offers a universal method for finding a unique or multiple DC operating points of nonlinear circuits. The developed method is based on the theory known as a linear complementarity problem (LCP) and the homotopy concept. It is a combination of Lemke’s method for solving LCP and some variant of the homotopy method. To express the problem of finding DC operating points in terms of LCP, an appropriate piecewise–linear approximation of diode characteristic is proposed. Although the method does not guarantee finding all the DC operating points, usually it finds them. The method is very fast and remarkably efficient. Numerical examples, including practical BJT and CMOS circuits having a unique or multiple DC operating points are given.  相似文献   

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提出了一种改进的角度抛光方法来测量硅片的亚表面损伤.其原理是:经过研磨和化学机械抛光后,起保护作用的陪片靠近胶黏剂的一端形成一个无损伤的、完整的劈尖,劈尖的棱边作为测量亚表面损伤的基准;角度抛光的倾斜角可通过劈尖上面产生的干涉条纹准确地测量得到.采用这种方法可以方便、准确地测量硅片由切割、研磨和磨削引起的亚表面损伤,其能够测量的最小损伤深度为几百纳米.  相似文献   

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Wei  S. L.  Qin  W. B.  Cheng  F. Y.  Wang  J. S. 《Wireless Personal Communications》2018,103(1):307-318
Wireless Personal Communications - Because the environment is bad in the coal mine, it is difficult to establish an effective information sharing network. Low voltage–power line has many...  相似文献   

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A Method for Auto-Inputting Color Maps   总被引:1,自引:0,他引:1  
1IntroductionThetechniqueofautomaticinputandrecognitionofmapshasdrawnmoreandmoreatentionrecently,foritcanaceleratetheinputpro...  相似文献   

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