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101.
Gong Shengrong Guo Li Cui Zhiming 《电子科学学刊(英文版)》2007,24(6):815-820
Block matching has been used for motion estimation and motion compensation in the Audio and Video Standard (AVS) for years. While having an acceptable performance in describing motion between frames, it requires quite a few bits to represent the motion vectors. In certain circumstances, the use of global motion estimation and compensation would perform equally well or even better than the block matching in terms of motion accuracy, while it results in the coding of global motion model parameters. In this letter, we modify an AVS coder by adding (1) six global motion model parameters to the frame header, and (2) mode selection among INTRA, SKIP, INTER-16×16, INTER-16×8, INTER-8×16, INTER-8×8, and Global Motion Compensation (GMC) modes by Lagrange optimal rate-distortion criteria. Simulation results demonstrate that over 0.1dB improvement in PSNR is obtained compared to the AVS coder for an average coded P-frame with the same bitrate. 相似文献
102.
Exploring new synaptic electronic devices that combine computing and memory is a promising strategy that fundamentally approaches intelligent machines. In this study, the multilevel resistive switching and synaptic behaviors of a MnO-based device is studied. The device is composed of Al/MnO/Ni sandwich structure, has stable resistance switching characteristics, has continuous nonvolatile memory state, can be used as electrically programmable and erasable analog memory. The gradual conductance modulation is realized by changing the compliance current and the maximum scanning voltage. The Al/MnO/Ni devices successfully mimic the basic functions of synapses, including the paired-pulse facilitation, spike-rate-dependent plasticity, excitatory postsynaptic current, short-term plasticity, long-term plasticity, and sike-timing-dependent plasticity. 相似文献
103.
High Efficiency Video Coding (HEVC) surpasses its predecessors in encoding efficiency by introducing new coding tools at the cost of an increased encoding time-complexity. The Coding Tree Unit (CTU) is the main building block used in HEVC. In the HEVC standard, frames are divided into CTUs with the predetermined size of up to 64 × 64 pixels. Each CTU is then divided recursively into a number of equally sized square areas, known as Coding Units (CUs). Although this diversity of frame partitioning increases encoding efficiency, it also causes an increase in the time complexity due to the increased number of ways to find the optimal partitioning. To address this complexity, numerous algorithms have been proposed to eliminate unnecessary searches during partitioning CTUs by exploiting the correlation in the video. In this paper, existing CTU depth decision algorithms for HEVC are surveyed. These algorithms are categorized into two groups, namely statistics and machine learning approaches. Statistics approaches are further subdivided into neighboring and inherent approaches. Neighboring approaches exploit the similarity between adjacent CTUs to limit the depth range of the current CTU, while inherent approaches use only the available information within the current CTU. Machine learning approaches try to extract and exploit similarities implicitly. Traditional methods like support vector machines or random forests use manually selected features, while recently proposed deep learning methods extract features during training. Finally, this paper discusses extending these methods to more recent video coding formats such as Versatile Video Coding (VVC) and AOMedia Video 1(AV1). 相似文献
104.
The Wyner-Ziv distributed video coding scheme is characterized for its intraframe encoder and interframe decoder which can also approach the efficiency of an interframe encoder-decoder system. In Wyner-Ziv residual coding of video, the residual of a frame with respect to a reference frame is Wyner-Ziv encoded, which can reduces the input entropy and leads to a higher coding efficiency than directly encoding the original frame. In this paper, we propose a new approach of residual coding combined with Region Of Interest (ROI) extraction. Experimental results show that, the proposed scheme achieves better rate-distortion performance compared to conventional Wyner-Ziv coding scheme. 相似文献
105.
Nuno P. Faísca Pedro M. Saraiva Berç Rustem Efstratios N. Pistikopoulos 《Computational Management Science》2009,6(4):377-397
In this paper, we outline the foundations of a general global optimisation strategy for the solution of multilevel hierarchical
and general decentralised multilevel problems, based on our recent developments on multi-parametric programming and control
theory. The core idea is to recast each optimisation subproblem, present in the hierarchy, as a multi-parametric programming
problem, with parameters being the optimisation variables belonging to the remaining subproblems. This then transforms the
multilevel problem into single-level linear/convex optimisation problems. For decentralised systems, where more than one optimisation
problem is present at each level of the hierarchy, Nash equilibrium is considered. A three person dynamic optimisation problem
is presented to illustrate the mathematical developments. 相似文献
106.
Construction of parametric biorthogonal wavelet filter banks with two parameters for image coding 总被引:1,自引:0,他引:1
We had presented a simple technique, which is based on the theory of Diophantine equation, for parametrization of popular
biorthogonal wavelet filter banks (BWFBs) having the linear phase and arbitrary multiplicity of vanishing moments (VMs), and
constructed a type of parametric BWFBs with one free parameter [15]. Here we generalize this technique to the case of two
parameters, and construct a type of parametric BWFBs with two free parameters. The closed-form parameter expressions of the
BWFBs are derived, with which any two-parameter family of BWFBs having preassigned VMs can be constructed, and six families,
i.e., 9/11, 10/10, 13/11, 10/14, 17/11, and 10/18 families, are considered here. Two parameters provide two degrees of freedom
to optimize the resulting BWFBs with respect to other criteria. In particular, in each family, three specific rational-coefficient
BWFBs with attractive features are obtained by adjusting the parameters: the first is not only very close to a quadrature
mirror filter (QMF) bank, but has optimum coding gain; the second possesses characteristics that are close to the irrational
BWFB with maximum VMs by Cohen et al.; and the last which has binary coefficients can realize a multiplication-free discrete
wavelet transform. In addition, two BWFBs are systematically verified to exhibit performance competitive to several state-of-the-art
BWFBs for image compression, and yet require lower computational costs.
This work was supported by the Natural Science Foundation of Jiangsu province, China under Grant 07KJD520005. 相似文献
107.
Fake pharmaceuticals inflicts severely upon people(?)~-s health through its circulation in markets.To strengthen the supervision of the pharmaceutical market,China is improving and is perfecting its national coding system in the field of pharmaceuticals. Bar-code tag and IC tag are available to the coding system.This paper summarizes the significance of IC tag to the supervision of pharmaceuticals and gives us a strategically general prospect of pharmaceutical supervision. 相似文献
108.
109.
Data in social and behavioral sciences are often hierarchically organized. Special statistical procedures have been developed to analyze such data while taking into account the resulting dependence of observations. Most of these developments require a multivariate normality distribution assumption. It is important to know whether normal theory-based inference can still be valid when applied to nonnormal hierarchical data sets. Using an analytical approach for balanced data and numerical illustrations for unbalanced data, this paper shows that the likelihood ratio statistic based on the normality assumption is asymptotically robust for many nonnormal distributions. The result extends the scope of asymptotic robustness theory that has been established in different contexts. 相似文献
110.
Aaron Potechin 《Designs, Codes and Cryptography》2008,46(3):243-259
We show that there are no complete 44-caps in AG(5, 3). We then use this result to prove that the maximal size for a cap in
AG(6, 3) is equal to 112, and that the 112-caps in AG(6, 3) are unique up to affine equivalence.
相似文献