期刊文献+
共找到11,057篇文章
< 1 2 250 >
每页显示 20 50 100
Computing the Moore-Penrose Inverse of a Matrix Through Symmetric Rank-One Updates 被引量:1
1
作者 Xuzhou Chen Jun Ji 《American Journal of Computational Mathematics》 2011年第3期147-151,共5页
This paper presents a recursive procedure to compute the Moore-Penrose inverse of a matrix A. The method is based on the expression for the Moore-Penrose inverse of rank-one modified matrix. The computational complexi... This paper presents a recursive procedure to compute the Moore-Penrose inverse of a matrix A. The method is based on the expression for the Moore-Penrose inverse of rank-one modified matrix. The computational complexity of the method is analyzed and a numerical example is included. A variant of the algorithm with lower computational complexity is also proposed. Both algorithms are tested on randomly generated matrices. Numerical performance confirms our theoretic results. 展开更多
关键词 FINITE RECURSIVE Algorithm Moore-Penrose INVERSE SYMMETRIC rank-one update
在线阅读 下载PDF
Sparse two-sided rank-one updates for nonlinear equations
2
作者 CHENG MingHou DAI YuHong 《Science China Mathematics》 SCIE 2010年第11期2907-2915,共9页
The two-sided rank-one(TR1)update method was introduced by Griewank and Walther(2002)for solving nonlinear equations.It generates dense approximations of the Jacobian and thus is not applicable to large-scale sparse p... The two-sided rank-one(TR1)update method was introduced by Griewank and Walther(2002)for solving nonlinear equations.It generates dense approximations of the Jacobian and thus is not applicable to large-scale sparse problems.To overcome this difficulty,we propose sparse extensions of the TR1 update and give some convergence analysis.The numerical experiments show that some of our extensions are superior to the TR1 update method.Some convergence analysis is also presented. 展开更多
关键词 TR1 update Broyden rank-one update SPARSITY
原文传递
P4LoF: Scheduling Loop-Free Multi-Flow Updates in Programmable Networks
3
作者 Jiqiang Xia Qi Zhan +2 位作者 Le Tian Yuxiang Hu Jianhua Peng 《Computers, Materials & Continua》 2026年第1期1236-1254,共19页
The rapid growth of distributed data-centric applications and AI workloads increases demand for low-latency,high-throughput communication,necessitating frequent and flexible updates to network routing configurations.H... The rapid growth of distributed data-centric applications and AI workloads increases demand for low-latency,high-throughput communication,necessitating frequent and flexible updates to network routing configurations.However,maintaining consistent forwarding states during these updates is challenging,particularly when rerouting multiple flows simultaneously.Existing approaches pay little attention to multi-flow update,where improper update sequences across data plane nodes may construct deadlock dependencies.Moreover,these methods typically involve excessive control-data plane interactions,incurring significant resource overhead and performance degradation.This paper presents P4LoF,an efficient loop-free update approach that enables the controller to reroute multiple flows through minimal interactions.P4LoF first utilizes a greedy-based algorithm to generate the shortest update dependency chain for the single-flow update.These chains are then dynamically merged into a dependency graph and resolved as a Shortest Common Super-sequence(SCS)problem to produce the update sequence of multi-flow update.To address deadlock dependencies in multi-flow updates,P4LoF builds a deadlock-fix forwarding model that leverages the flexible packet processing capabilities of the programmable data plane.Experimental results show that P4LoF reduces control-data plane interactions by at least 32.6%with modest overhead,while effectively guaranteeing loop-free consistency. 展开更多
关键词 Network management update consistency programmable data plane P4
在线阅读 下载PDF
Cognitive Erasure-Coded Data Update and Repair for Mitigating I/O Overhead
4
作者 Bing Wei Ming Zhong +2 位作者 Qian Chen Yi Wu Yubin Li 《Computers, Materials & Continua》 2026年第2期1706-1725,共20页
In erasure-coded storage systems,updating data requires parity maintenance,which often leads to significant I/O amplification due to“write-after-read”operations.Furthermore,scattered parity placement increases disk ... In erasure-coded storage systems,updating data requires parity maintenance,which often leads to significant I/O amplification due to“write-after-read”operations.Furthermore,scattered parity placement increases disk seek overhead during repair,resulting in degraded system performance.To address these challenges,this paper proposes a Cognitive Update and Repair Method(CURM)that leverages machine learning to classify files into writeonly,read-only,and read-write categories,enabling tailored update and repair strategies.For write-only and read-write files,CURM employs a data-differencemechanism combined with fine-grained I/O scheduling to minimize redundant read operations and mitigate I/O amplification.For read-write files,CURM further reserves adjacent disk space near parity blocks,supporting parallel reads and reducing disk seek overhead during repair.We implement CURM in a prototype system,Cognitive Update and Repair File System(CURFS),and conduct extensive experiments using realworld Network File System(NFS)and Microsoft Research(MSR)workloads on a 25-node cluster.Experimental results demonstrate that CURMimproves data update throughput by up to 82.52%,reduces recovery time by up to 47.47%,and decreases long-term storage overhead by more than 15% compared to state-of-the-art methods including Full Logging(FL),ParityLogging(PL),ParityLoggingwithReservedspace(PLR),andPARIX.These results validate the effectiveness of CURM in enhancing both update and repair performance,providing a scalable and efficient solution for large-scale erasure-coded storage systems. 展开更多
关键词 Erasure coding machine learning cognitive update and repair I/O amplification mitigation seekefficient recovery
在线阅读 下载PDF
A New Encryption Mechanism Supporting the Update of Encrypted Data for Secure and Efficient Collaboration in the Cloud Environment
5
作者 Chanhyeong Cho Byeori Kim +1 位作者 Haehyun Cho Taek-Young Youn 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期813-834,共22页
With the rise of remote collaboration,the demand for advanced storage and collaboration tools has rapidly increased.However,traditional collaboration tools primarily rely on access control,leaving data stored on cloud... With the rise of remote collaboration,the demand for advanced storage and collaboration tools has rapidly increased.However,traditional collaboration tools primarily rely on access control,leaving data stored on cloud servers vulnerable due to insufficient encryption.This paper introduces a novel mechanism that encrypts data in‘bundle’units,designed to meet the dual requirements of efficiency and security for frequently updated collaborative data.Each bundle includes updated information,allowing only the updated portions to be reencrypted when changes occur.The encryption method proposed in this paper addresses the inefficiencies of traditional encryption modes,such as Cipher Block Chaining(CBC)and Counter(CTR),which require decrypting and re-encrypting the entire dataset whenever updates occur.The proposed method leverages update-specific information embedded within data bundles and metadata that maps the relationship between these bundles and the plaintext data.By utilizing this information,the method accurately identifies the modified portions and applies algorithms to selectively re-encrypt only those sections.This approach significantly enhances the efficiency of data updates while maintaining high performance,particularly in large-scale data environments.To validate this approach,we conducted experiments measuring execution time as both the size of the modified data and the total dataset size varied.Results show that the proposed method significantly outperforms CBC and CTR modes in execution speed,with greater performance gains as data size increases.Additionally,our security evaluation confirms that this method provides robust protection against both passive and active attacks. 展开更多
关键词 Cloud collaboration mode of operation data update efficiency
在线阅读 下载PDF
Updates of CSCO guidelines for colorectal cancer version 2025 被引量:1
6
作者 Demin Lu Caixia Dong +4 位作者 Kailai Wang Chenyang Ye Liubo Chen Ying Yuan Hanguang Hu 《Chinese Journal of Cancer Research》 2025年第3期297-302,共6页
Colorectal cancer(CRC)is the most frequently diagnosed malignancy of the digestive system and the second leading cause of cancer-related deaths worldwide(1).In China,CRC ranks as the second most common cancer with inc... Colorectal cancer(CRC)is the most frequently diagnosed malignancy of the digestive system and the second leading cause of cancer-related deaths worldwide(1).In China,CRC ranks as the second most common cancer with incidence and mortality rates continuing to rise(2).The Chinese Society of Clinical Oncology(CSCO)first introduced its guidelines in 2017,and since then,they have been updated annually to incorporate the latest clinical research findings,drug availability,and expert consensus(3-8).This article presents the key updates in the 2025 edition compared to the 2024 version. 展开更多
关键词 digestive system colorectal cancer VERSION clinical research findings updateS CSCO guidelines edition colorectal cancer crc
暂未订购
THE INVERSE EIGENPROBLEM WITH RANK-ONE UPDATING AND ITS STABLITY
7
作者 苏仰锋 蒋尔雄 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1994年第1期87-95,共9页
Let ∑, Г be two n-by-n diagonal matrices with σi,γi as their diagonals. For the inverse eigenvalue problem: look for y∈Rn such that Г + yyT is similar to ∑, we prove thatu also the sufficient condition for the ... Let ∑, Г be two n-by-n diagonal matrices with σi,γi as their diagonals. For the inverse eigenvalue problem: look for y∈Rn such that Г + yyT is similar to ∑, we prove thatu also the sufficient condition for the solvability of this inverse problem. Its solution (set) is given explicitly. In some case, the problem is unstable. But we prove that the sums of the square of some contigious components keep stable, i.e., small sum keeps small, large sum has a small relative perturbation, see Theorem 3. 展开更多
关键词 INVERSE EIGENPROBLEM rank-one updating stablity
在线阅读 下载PDF
Corrigendum regarding updated Declaration of Competing Interest statements in previously published articles
8
《Resources Chemicals and Materials》 2025年第3期156-156,共1页
Declaration of Competing Interest statements is updated in the published version of the following articles that appeared in issues of Resources Chemicals and Materials.The appropriate updated Declaration of Competing ... Declaration of Competing Interest statements is updated in the published version of the following articles that appeared in issues of Resources Chemicals and Materials.The appropriate updated Declaration of Competing Interest state-ments,provided by the Authors,are included below. 展开更多
关键词 declaration competing interest statements ARTICLES declaration competing interest CORRIGENDUM competing interest DECLARATION updateS PUBLICATIONS
在线阅读 下载PDF
Efficient One-Way Time Synchronization for VANET withMLE-Based Multi-Stage Update
9
作者 Hyeontae Joo Sangmin Lee +1 位作者 Kiseok Kim Hwangnam Kim 《Computers, Materials & Continua》 2025年第8期2789-2804,共16页
As vehicular networks become increasingly pervasive,enhancing connectivity and reliability has emerged as a critical objective.Among the enabling technologies for advanced wireless communication,particularly those tar... As vehicular networks become increasingly pervasive,enhancing connectivity and reliability has emerged as a critical objective.Among the enabling technologies for advanced wireless communication,particularly those targeting low latency and high reliability,time synchronization is critical,especially in vehicular networks.However,due to the inherent mobility of vehicular environments,consistently exchanging synchronization packets with a fixed base station or access point is challenging.This issue is further exacerbated in signal shadowed areas such as urban canyons,tunnels,or large-scale indoor hallswhere other technologies,such as global navigation satellite system(GNSS),are unavailable.One-way synchronization techniques offer a feasible approach under such transient connectivity conditions.One-way schemes still suffer from long convergence times to reach the required synchronization accuracy in these circumstances.In this paper,we propose a WLAN-based multi-stage clock synchronization scheme(WMC)tailored for vehicular networks.The proposed method comprises an initial hard update stage to rapidly achieve synchronization,followed by a high-precision stable stage based on Maximum Likelihood Estimation(MLE).By implementing the scheme directly at the network driver,we address key limitations of hard update mechanisms.Our approach significantly reduces the initial period to collect high-quality samples and offset estimation time to reach sub-50μs accuracy,and subsequently transitions to a refined MLE-based synchronization stage,achieving stable accuracy at approximately 30μs.The windowed moving average stabilized(reaching 90%of the baseline)in approximately 35 s,which corresponds to just 5.1%of the baseline time accuracy.Finally,the impact of synchronization performance on the localization model was validated using the Simulation of Urban Mobility(SUMO).The results demonstrate that more accurate conditions for position estimation can be supported,with an improvement about 38.5%in the mean error. 展开更多
关键词 One-way time synchronization maximum likelihood estimation hybrid clock update
在线阅读 下载PDF
An improved fluid flow algorithm for hydraulic fracturing:Optimizing domain volume and crack pressure update strategies
10
作者 Wei Zhang Jing Bi +3 位作者 Yu Zhao Yongfa Zhang Chaolin Wang Yang Pan 《International Journal of Mining Science and Technology》 2025年第4期639-657,共19页
With the widespread adoption of hydraulic fracturing technology in oil and gas resource development,improving the accuracy and efficiency of fracturing simulations has become a critical research focus.This paper propo... With the widespread adoption of hydraulic fracturing technology in oil and gas resource development,improving the accuracy and efficiency of fracturing simulations has become a critical research focus.This paper proposes an improved fluid flow algorithm,aiming to enhance the computational efficiency of hydraulic fracturing simulations while ensuring computational accuracy.The algorithm optimizes the aperture law and iteration criteria,focusing on improving the domain volume and crack pressure update strategy,thereby enabling precise capture of dynamic borehole pressure variations during injection tests.The effectiveness of the algorithm is verified through three flow-solid coupling cases.The study also analyzes the effects of borehole size,domain volume,and crack pressure update strategy on fracturing behavior.Furthermore,the performance of the improved algorithm in terms of crack propagation rate,micro-crack formation,and fluid pressure distribution was further evaluated.The results indicate that while large-size boreholes delay crack initiation,the cracks propagate more rapidly once formed.Additionally,the optimized domain volume calculation and crack pressure update strategy significantly shorten the pressure propagation stage,promote crack propagation,and improve computational efficiency. 展开更多
关键词 Hydraulic fracturing Fluid flow algorithm Domain volume optimization Crack pressure update Borehole size
在线阅读 下载PDF
AN ITERATED-SUBSPACEMINIMIZATION METHODS WITHSYMMETRIC RANK-ONE UPDATING 被引量:1
11
作者 徐徽宁 孙麟平 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2004年第2期233-240,共8页
We consider an Iterated-Subspace Minimization(ISM) method for solving large-scale unconstrained minimization problems. At each major iteration of the method,a two-dimensional manifold, the iterated subspace, is constr... We consider an Iterated-Subspace Minimization(ISM) method for solving large-scale unconstrained minimization problems. At each major iteration of the method,a two-dimensional manifold, the iterated subspace, is constructed and an approximate minimizer of the objective function in this manifold then determined, and a symmetric rank-one updating is used to solve the inner minimization problem. 展开更多
关键词 大型无约束最优化 迭代子空间最小化 无约束规划 对称秩单较正
在线阅读 下载PDF
Chinese Society of Clinical Oncology Non-small Cell Lung Cancer(CSCO NSCLC)guidelines in 2024:key update on the management of early and locally advanced NSCLC
12
作者 Siyuan Chen Zhijie Wang Boyang Sun 《Cancer Biology & Medicine》 2025年第3期191-196,共6页
The Chinese Society of Clinical Oncology Non-small Cell Lung Cancer(CSCO NSCLC)guidelines were first published in 2016,ranking among the earliest-released guidelines within the CSCO series.In 2020 the CSCO published s... The Chinese Society of Clinical Oncology Non-small Cell Lung Cancer(CSCO NSCLC)guidelines were first published in 2016,ranking among the earliest-released guidelines within the CSCO series.In 2020 the CSCO published separate guidelines for NSCLC and small cell lung cancer(SCLC)for the first time to improve clinical usability. 展开更多
关键词 improve clinical usability Clinical Usability Chinese Society Clinical Oncology Non Small Cell Lung Cancer update CSCO NSCLC Guidelines Early NSCLC Locally Advanced NSCLC
暂未订购
Gain adaptive tuning method for fiber Raman amplifier based on two-stage neural networks and double weights updates
13
作者 MU Kuanlin WU Yue 《Optoelectronics Letters》 2025年第5期284-289,共6页
We present a gain adaptive tuning method for fiber Raman amplifier(FRA) using two-stage neural networks(NNs) and double weights updates. After training the connection weights of two-stage NNs separately in training ph... We present a gain adaptive tuning method for fiber Raman amplifier(FRA) using two-stage neural networks(NNs) and double weights updates. After training the connection weights of two-stage NNs separately in training phase, the connection weights of the unified NN are updated again in verification phase according to error between the predicted and target gains to eliminate the inherent error of the NNs. The simulation results show that the mean of root mean square error(RMSE) and maximum error of gains are 0.131 d B and 0.281 d B, respectively. It shows that the method can realize adaptive adjustment function of FRA gain with high accuracy. 展开更多
关键词 gain adaptive tuning connection weights error predicted target gains training connection weights unified nn gain adaptive tuning method double weights updates fiber raman amplifier fra
原文传递
Time-varying reliability analysis of a reservoir bank slope considering creep behavior and sequential Bayesian updating
14
作者 Wenyu Zhuang Qingchao Lyu +4 位作者 Yaoru Liu Kai Zhang Ting Liu Junlei Bai Qun Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第3期2104-2121,共18页
The probabilistic stability evolution analysis of reservoir bank slopes is a crucial aspect of risk assessment,with core challenges including the consideration of deformation mechanisms and accurate determination of m... The probabilistic stability evolution analysis of reservoir bank slopes is a crucial aspect of risk assessment,with core challenges including the consideration of deformation mechanisms and accurate determination of mechanical parameters.In this study,a novel time-varying reliability analysis framework based on sequential Bayesian updating of mechanical parameters is proposed.The inverse parameters account for damage time-dependent behavior,incorporating water effect and a strain-driven softening-hardening process that depends on sliding states.The likelihood function is enhanced to simultaneously consider observation error,surrogate model prediction error,and model structural error,with the introduction of physical penalty.Exploration of the high-dimensional parameter space is achieved via the Hamiltonian Monte Carlo(HMC)method and the physics knowledge-based time-dependent deformation surrogate model.The time-varying reliability analysis of the slope is performed using the multi-grid method.Taking a reservoir bank slope as a case study,the sequential updating of 12 mechanical parameters is conducted based on deformation time series from 16 monitoring points,thereby validating the proposed framework.The results indicate that the proposed framework effectively captures the posterior distribution of mechanical parameters,with the case slope remaining in a critically stable state after overall sliding,showing a high failure probability.Introducing model structural error can reduce parameter compensation,and a reasonable sequential updating step size can improve inversion accuracy. 展开更多
关键词 Sequential Bayesian updating Probabilistic back analysis Time-varying reliability Reservoir bank slope Model structural error Surrogate model prediction error Markov chain Monte Carlo(MCMC)method Multi-grid method
在线阅读 下载PDF
架设局域网内的Update服务器
15
作者 贾大江 宋晓涛 《山西电力》 2004年第4期64-65,共2页
越来越多的病毒利用微软操作系统的漏洞传播,及时给系统升级打补丁成了计算机管理的一项重要工作。在局域网内架设软件升级服务器,可以提高升级系统的效率。为计算机系统的安全运行提供保障。
关键词 局域网 update服务器 网络管理员 工作组
在线阅读 下载PDF
BGP协议中UPDATE报文的并行化处理方法 被引量:2
16
作者 丁利娜 王兴伟 +1 位作者 李福亮 黄敏 《小型微型计算机系统》 CSCD 北大核心 2016年第11期2459-2463,共5页
互联网的规模日益扩大,作为域间路由协议标准的BGP协议,其性能面临着前所未有的考验.而路由更新(UPDATE)报文仍采用串行化的方式来处理,处理速度慢,极大地影响了BGP协议的性能.为此,提出一种UPDATE报文的并行化处理方法来解决这个问题.... 互联网的规模日益扩大,作为域间路由协议标准的BGP协议,其性能面临着前所未有的考验.而路由更新(UPDATE)报文仍采用串行化的方式来处理,处理速度慢,极大地影响了BGP协议的性能.为此,提出一种UPDATE报文的并行化处理方法来解决这个问题.该方法采用流水线技术和多线程技术,能够提高UPDATE报文的处理速度.为了进一步提高该方法的效率,我们在UPDATE报文的并行化处理过程中引入了垃圾回收机制和多线程动态调节策略.最后,我们在Quagga原型系统上对该并行化处理方法进行了仿真实现,并与Quagga中原始的BGPD模块的测试结果进行了对比分析,实验结果表明,本文设计的UPDATE报文的并行化处理方法是可行且有效的. 展开更多
关键词 BGP协议 update报文 并行化处理 流水线 多线程
在线阅读 下载PDF
基于TQuery与TUpdateQuery的多表缓冲更新技术
17
作者 刘惊雷 《计算机工程》 CAS CSCD 北大核心 2004年第24期159-161,179,共4页
以C++Builder中的TQuery和TUpdatequery控件为例,阐述了进行现场数据的查询和缓冲更新的原理和技术,并解决了更新查询中的多个基表的问题。同时介绍了TDataSource控件的动态数据交换与验证的功能。最后在计算机上编制程序实现了以数据... 以C++Builder中的TQuery和TUpdatequery控件为例,阐述了进行现场数据的查询和缓冲更新的原理和技术,并解决了更新查询中的多个基表的问题。同时介绍了TDataSource控件的动态数据交换与验证的功能。最后在计算机上编制程序实现了以数据缓冲技术实现多表更新的问题。 展开更多
关键词 数据缓冲区 缓冲更新 多表更新 动态数据交换
在线阅读 下载PDF
ORACLE游标中的多表UPDATE行锁讨论 被引量:3
18
作者 张练兴 马明磊 《江西师范大学学报(自然科学版)》 CAS 北大核心 2005年第6期489-491,共3页
介绍了Oracle中的封锁机制,分析了共享更新封锁的特点,并就游标中的多表更新行锁以及怎样避免死锁错误进行了讨论.
关键词 ORACLE数据库 游标 多表update行锁
在线阅读 下载PDF
云环境下基于XUpdate的XML更新研究
19
作者 张涛 方少卿 《长春师范大学学报》 2018年第6期80-84,共5页
本文在研究XUpdate语言的基础上,构建了一种基于XUpdate的更新处理架构,面对云计算环境下大量的XML数据的管理,为更新XML文档提出了一种通用的模式和规范。
关键词 XML更新 Xupdate 云计算
在线阅读 下载PDF
蠕虫“Update-Factor”传播模型研究
20
作者 张殿旭 张怡 《计算机应用》 CSCD 北大核心 2008年第B06期66-70,共5页
双因素模型考虑了人为对抗因素和蠕虫传播对路由造成的冲击,较SI模型、SIS模型和KM模型更能符合蠕虫传播的实际情况。但它不能反映蠕虫传播后期的特性,同时模型没有考虑大规模系统升级程序和自动补丁程序这一重要的对抗因素对蠕虫传播... 双因素模型考虑了人为对抗因素和蠕虫传播对路由造成的冲击,较SI模型、SIS模型和KM模型更能符合蠕虫传播的实际情况。但它不能反映蠕虫传播后期的特性,同时模型没有考虑大规模系统升级程序和自动补丁程序这一重要的对抗因素对蠕虫传播的影响。针对双因素模型的不足,对其进行了改进,提出了"Update-Factor"模型,经仿真结果与实际监测结果比较,模型克服了双因素模型的不足,更符合蠕虫传播的实际情况。 展开更多
关键词 双因素模型 update-Factor模型 蠕虫传播模型
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部