检索结果-南通市图书馆

error control Strategies for Numerical Integrations in Fast Collocation Methods

在线全文

学校读者我要写书评

暂无评论

Northeastern Mathematical Journal 2005年第2期21卷 233-252页

作者：陈仲英巫斌许跃生 Department of Scientific Computing Zhongshan University Guangzhou 510275 Department of Mathematics Syracuse University Syracuse NY 13244 U.S.A. and Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080

We propose two error control techniques for numerical integrations in fast multiscale collocation methods for solving Fredholm integral equations of the second kind with weakly singular kernels. Both techniques utilize quadratures for singular integrals using graded points. One has a polynomial order of accuracy if the integrand has a polynomial order of smoothness except at the singular point and the other has exponential order of accuracy if the integrand has an infinite order of smoothness except at the singular point. We estimate the order of convergence and computational complexity of the corresponding approximate solutions of the equation. We prove that the second technique preserves the order of convergence and computational complexity of the original collocation method. Numerical experiments are presented to illustrate the theoretical estimates.

关键词： Fredholm integral equation of the second kind fast collocation method quadrature rule error control

A New Class of Nonlinear error control Codes Based on Neural Networks

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Transportation 1995年第2期12卷 109-116页

作者： Jin Fan Fan Junbo Deng Xingming(School of Computer and Communicalion Engineering,Southwest Jiaolong University),Chengdu 610031, Chiua

By mcans of stable attractors of discret Hopfield neural network (DHNN) , anew class of nonlinear error control codes is sugsested and some relativetheorems are presented. A kind of single error control codes is also ... 详细信息

关键词： error control neural networks nonlinear codes

Based on Adaptive Backstepping error control for Permanent Magnet Synchronous Motor

在线全文

学校读者我要写书评

暂无评论

Intelligent control and Automation 2016年第2期7卷 17-24页

作者： Hua Jiang Da Lin Yongchun Liu Hong Song School of Automatic and Electronic Information Sichuan University of Science and Engineering Zigong China

Permanent Magnet Synchronous Motor (PMSM) displays chaotic phenomenon when PMSM in power on or power off. At present, there are many methods to control chaos in PMSM. However, there appears oscillation in course of control chaos in PMSM, which has an effect on practical application. This paper proposes error control based on adaptive backstepping to control chaos in PMSM;an error control item is added in each step virtual control design which has control effect of unknown dynamical error on system. This scheme can eliminate oscillation in course of control chaos. Finally, the simulation results show the effectiveness of theoretical analysis.

关键词： PMSM error control Adaptive Backstepping Chaos control

Technical Analysis on Application Layer error control in IPTV

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

ZTE Communications 2010年第1期8卷 55-59页

作者： Xia Hongfei Lue Xiaopeng Liu Feng ZTE Corporation Nanjing 210012 P. R. China Image Processing and Image Communication Laboratory of Jiangsu Province Nanjing University of Posts and Telecommunications Nanjing 210003 P. R. China

When they provide Internet Protocol Television （IRTV） services, IP networks face difficulties such as reduced transmission bandwidth, delay, jitter, and packet loss. A terminal-centric solution can improve the image quality by adding control policies like congestion control and error control to the receiving terminal and source code. An end-to-end application layer reliability method is usually required to satisfy IPTV requirements in the IP network. Application Layer Forward error Correction （AL-FEC） technology solves the problem of packet loss, and can ensure the end-to-end reliability for IPrV services.

关键词： IPTV error control Application Layer Forward error Correction transmission bandwidth reliability packet loss congestion control Internet Protocol services image quality error control difficulties technology solution required improve jitter delay face

Location,Localization,and Localizability

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2010年第2期25卷 274-297页

作者：刘云浩杨铮王小平简丽荣 Department of Computer Science and Engineering Hong Kong University of Science and Technology

Location-aware technology spawns numerous unforeseen pervasive applications in a wide range of living, pro- duction, commence, and public services. This article provides an overview of the location, localization, and localizability issues of wireless ad-hoc and sensor networks. Making data geographically meaningful, location information is essential for many applications, and it deeply aids a number of network functions, such as network routing, topology control, coverage, boundary detection, clustering, etc. We investigate a large body of existing localization approaches with focuses on error control and network localizability, the two rising aspects that attract significant research interests in recent years. error control aims to alleviate the negative impact of noisy ranging measurement and the error accumulation effect during coope- rative localization process. Network localizability provides theoretical analysis on the performance of localization approaches, providing guidance on network configuration and adjustment. We emphasize the basic principles of localization to under- stand the state-of-the-art and to address directions of future research in the new and largely open areas of location-aware technologies.

关键词： location-based services (LBS) localization error control localizability wireless ad-hoc and sensor networks

General design principle of artillery for firing accuracy

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第12期18卷 2125-2140页

作者： Linfang Qian Guangsong Chen Minghao Tong Jinsong Tang School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China

In this paper,based on the topological description method,the kinematic and dynamic equations of the projectile flight and projectile-artillery coupling system during the whole process of firing are *** factors that can affect the projectile burst points,namely the state parameters of the projectile on the muzzle and state parameters of the barrel muzzle,as well as the factors that affect the barrel muzzle state parameters,are *** this basis,the design principle of artillery firing accuracy is *** error analysis and the corresponding inverse problem,the extraction method of key parameters affecting artillery implicated motion,the conformal and control method of rotating band are analyzed and ***,the presented method is verified through a vehicle mounted howitzer case,and the muzzle state parameter interval is obtained meeting the given firing *** addition,the sensitivity analysis of artillery parameters shows that the less the correlation between the parameters and the barrel,the less the influence on the projectile implicated *** analysis of the coupling effect between rifling and the rotating band shows that the uniform rifling is the optimal form for the conformal of the rotating band during firing.

关键词： Firing accuracy Projectile-artillery coupling Rotating band conformal Sensitivity analysis error control

Robust spatio-temporal error concealment for packet- lossy H.264 video transmission

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2006年第3期13卷 87-92页

作者： LIAO Ning YAN Dan QUAN Zi-yi MEN Ai-dong Multimedia Center Beijing University of Posts and TelecommunicationsBeijing 100876 China

In this article, a spatio-temporal post-processing error concealment algorithm designed initially for a H.264 video-streaming scheme over packet-lossy networks has been presented. It aims at optimizing subjective quality of restored video and the conventional objective metric, peak signal-to-noise ratio （PSNR）, as well, under the constraints of low delay and computational complexity, which are critical to real-time applications and portable devices having limited resources. Specifically, it takes into consideration physical property of motion to achieve more meaningful perceptual video quality. Further, a content-adaptive bilinear spatial interpolation approach and a temporal error concealment approach are combined under a unified boundary match criterion based on texture and motion activity analysis. Extensive experiments have demonstrated that the proposal not only result in better reconstruction, objectively and subjectively, than the reference software model benchmark, but also results in better robustness to different video sequences.

关键词： error concealment error control H.264/JVT video transmission lossy transmission

An end-to-end robust approach for scalable video over the Internet

在线全文

学校读者我要写书评

暂无评论

Science in China(Series F) 2004年第2期47卷 246-259页

作者： WANGGuijin ZHANGQian ZHUWenwu LINXinggang DepartmentofElectronicEngineering TsinghuaUniversityBeijing100084China MicrosoftResearchAsia Beijing100080China

This paper introduces an end-to-end robust approach for scalable video over the Internet. The traditional method only considers congestion control, error control and is unable to achieve end-to-end high-quality video transmission in the error-prone environment like the Internet since it does not consider the packetization behavior, network conditions and the media characteristics simultaneously. This paper presents an end-to-end approach for scalable video over the Internet, combining network adaptive congestion control and unequal error control. Considering requirements of multimedia transmission, this paper introduces multimedia congestion control to estimate available bandwidth and smooth the media sending rate. Specially in the transport layer we propose unequal interleaving packetization method and unequal error protection scheme, which can alleviate the effect of the packet loss well. Further we develop the rate-distortion theory for the scalable video over the Internet. Thereafter the optimal bit allocation is presented to determine the bits budgets for the source part and error control part. Simulation shows our scheme can achieve good performance for scalable video over the Internet.

关键词： congestion control error control video transmission rate-distortion scalable video.

On Scientific Data and Image Compression Based on Adaptive Higher-Order FEM

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2009年第1期1卷 56-68页

作者： P.Solin D.Andrs Department of Mathematics and Statistics University of NevadaRenoUSA Institute of Thermomechanics PragueCzech Republic

We present a novel compression algorithm for 2D scientific data and images based on exponentially-convergent adaptive higher-order finite element methods(FEM).So far,FEM has been used mainly for the solution of partial differential equations(PDE),but we show that it can be applied to data and image compression *** adaptive compression algorithm is trivial compared to adaptive FEM algorithms for PDE since the error estimation step is not *** method attains extremely high compression rates and is able to compress a data set or an image with any prescribed error *** data and images are stored in the standard FEM format,which makes it possible to analyze them using standard PDE visualization *** examples are *** method is presented in such a way that it can be understood by readers who may not be experts of the finite element method.

关键词： Data compression image compression adaptive hp-FEM orthogonal projection best approximation problem error control