检索结果-南通市图书馆

Recommendation Method for Contrastive Enhancement of Neighborhood Information

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang beijing Zhou Lisi Zhang He Ma School of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

Periodicity Characteristic of TOAD's Switching Window

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

Chinese Journal of Lasers 2000年第2期9卷 161-166页

作者： LIU Xianbing,YE Peida (beijing university of posts and telecommunications, beijing 100876, china ) 北京邮电大学北京

The periodidity characteristic of switching window of a terahertz optical asymmetric demultiplexer (TOAD) using numerical simulation was investigated. The results show that the switching window width of TOAD changes periodically with the time asymmetry of TOAD and the period is one half of the period of control pulses. The theoretical results agree with the experimental results very well.

关键词： terahertz optical asymmetric demultiplexer (TOAD) Sendconductor optical amplifier (SOA) optical time division multiplexing (OTDM)

CONDITIONS FOR UNIFORMLY NON-CONFOUNDING OF CAUSAL DISTRIBUTION EFFECTS OVER MULTIPLE COVARIATES

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2010年第4期23卷 796-803页

作者： Xueli WANG School of Science,beijing university of posts and telecommunications,beijing 100876,china. School of Science Beijing University of Posts and Telecommunications Beijing China

Causation is a distinct concept from association and more important than association inepidemiologic *** paper proposes the concept of uniform non-confounding for causal distributioneffects over multiple covariates,and gives the sufficient conditions for uniform non-confoundingover a covariate set C including confounders or non-confounders,and also shows the conditions forconditionally non-confounding in the *** these conditions can be tested by observeddata.

关键词： Causal distribution effect confounding covariates uniform non-confounding

Neighborhood-following algorithms for linear programming

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2004年第6期47卷 812-820页

作者： Al WenbaoSchool of Science, beijing university of posts and telecommunications, beijing 100876, china School of Science Beijing University of Posts and Telecommunications Beijing China

In this paper, we present neighborhood-following algorithms for linear programming. When the neighborhood is a wide neighborhood, our algorithms are wide neighborhood primal-dual interior point algorithms. If the neighborhood degenerates into the central path, our algorithms also degenerate into path-following algorithms. We prove that our algorithms maintain the O9√nL) -iteration complexity still, while the classical wide neighborhood primal-dual interior point algorithms have only the O(nL-iteration complexity. We also proved that the algorithms are quadratic convergence if the optimal vertex is nondegenerate. Finally, we show some computational results of our algorithms.

关键词： linear programming primal-dual interior point methods wide neighborhood methods quadratic convergence

Study on International Contracting for Construction's Risk Identif ication and Strategy

在线全文

学校读者我要写书评

暂无评论

china Communications 2009年第2期6卷 106-111页

作者： Zhao Yumei, Lv Tingjie beijing university of posts and telecommunications, china beijing university of posts and telecommunications China

Risk management is a key part in project management. International contracting for construction is a market with high risk. Therefore, the most important task in international contracting for construction is the analysis and controlling of risks. In this paper, the risks of international contracting for construction are divided into macroenvironment risks and micro-risks. Risk management is to identify risk factors in the project life cycle, analyze and evaluate them, and take effective measures to maintain the highest standard of safety.

关键词： risk identifi cation international contracting for construcation risk management risk strategy

Analyzing the Switching Characteristics of a NOLM Demultiplexer with on Analytic and Numrical Methods

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Lasers 1999年第5期8卷 419-424页

作者： LIU XianbinG YE Peida(telecommunications Engineering School, beijing university of posts and telecommunications, beijing 100876 china) 北京邮电大学电信工程学院北京

The switching characteristics of a NOLM demultiplexer are investigated by using an analytic and numerical method. The results reveal that the switching characteristics of a NOLM demultiplexer depend on parameters such as the power coupling ratio of the coupler,the peak power of control pulses, the walk-off and the initial time delay between signal pulses and control pulses, etc. The efficiency of NOLM is dependent on the peak power of controlpulses However, the switching window profile begins to oscillate as the power exceeds a critica value and this will be detrimental to the demultiplexed signals. The signal-control pulse walk-off can broaden the switching window of NOLM, make the window profile deviate fromits central position, and decrease its switching efficiency.

关键词： OTDM NOLM demultiplexer all-optical switch

telecommunications Market and Regulation in India and Ireland

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

china Communications 2008年第2期5卷 83-87页

作者： Chen Xiuyu beijing university of posts and telecommunications,china beijing Univ posts & Telecommun Beijing Peoples R China

Information and communications technology is apillar industry in India and Ireland,playing an increasinglyimportant role in promoting the economicand social *** market competitionpromotes the rapid development of the *** market regulation andconstant legal system improvement can promote thesmooth development of the *** of new technology promotes a sustainabledevelopment of the *** is proposed that the pace of telecommunicationslegislation in china should be furtherquickened,telecommunications market structureoptimized,and telecommunications regulationstrengthened.

关键词： India Ireland telecommunications market regulation

SVM-based loss differentiation algorithm for wired-cum-wireless networks

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 2009年第4期16卷 104-111页

作者： DENG Qian-hua ,CAI An-ni School of Telecommunication Engineering,beijing university of posts and telecommunications,beijing 100876,china School of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In a hybrid wired-cum-wireless network environment, packet loss may happen because of congestion or wireless link errors. Therefore, differentiating the cause is important for helping transport protocols take actions to control congestion only when the loss is caused by congestion. In this article, an end-to-end loss differentiation mechanism is proposed to improve the transmission performance of transmission control protocol （TCP）-friendly rate control （TFRC） protocol. Its key design is the introduction of the outstanding machine learning algorithm - the support vector machine （SVM） into the network domain to perform multi-metric joint loss differentiation. The SVM is characterized by using end-to-end indicators for input, such as the relative one-way trip time and the inter-arrival time of packets fore-and-aft the loss, while requiring no support from intermediate network apparatus. Simulations are carried out to evaluate the loss differentiation algorithm with various network configurations, such as with different competing flows, wireless loss rate and queue size. The results show that the proposed classifier is effective under most scenarios, and that its performance is superior to the ZigZag, mBiaz and spike （ZBS） scheme.

关键词： machine learning SVM TCP-friendly rate control (TFRC) congestion control

Robust multiuser MIMO scheduling algorithms with imperfect CSI

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2012年第4期55卷 815-826页

作者： MAO JunLing 1,3,GAO JinChun 1,3,LIU YuanAn 1,3,XIE Gang 2,3 & ZHANG Jian 1,3 1 School of Electronic Engineering,beijing university of posts and telecommunications,beijing 100876,china 2 School of Information and Communication Engineering,beijing university of posts and telecommunications,beijing 100876,china 3 Key Lab of Universal Wireless Communications,Ministry of Education,beijing university of posts and telecommunications,beijing 100876,china School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing China Key Lab of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China

Robust multiuser multiple-input-multiple-output (MIMO) scheduling algorithms are proposed in this *** imperfect channel state information (CSI),traditional scheduling algorithms for the multiuser MIMO system based on the zero forcing precoding scheme will lose some performance due to the multi-user interference (MUI).In order to improve the system average throughput,we study the robust multiuser MIMO scheduling problem with imperfect *** the average capacity formula,we derive a robust factor which can transform the robust multiuser MIMO scheduling problem into the traditional one,thus most existing non-robust scheduling algorithms can be robust if this factor is *** results show that compared with the traditional algorithms,the proposed robust algorithms can improve the system average throughput significantly under the CSI error environment.

关键词： multiuser MIMO (MU-MIMO) scheduling robust imperfect CSI