检索结果-南通市图书馆

Recommendation Method for Contrastive Enhancement of Neighborhood information

在线全文

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

Natural convection gas pendulum and its application in accelerometer and tilt sensor

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

Progress in Natural Science:Materials International 2005年第9期15卷 857-860页

作者： ZHANG Fuxue(Research center of Sensor Technology, beijing information Technology Institute, beijing 100101, china) Research center of Sensor Technology Beijing Information Technology Institute Beijing 100101 China

It is discovered that the natural convection gas has the pendulum characteristic, which leads to the introduction of the new concept of gas pendulum. In this paper, the buoyancy lift of natural convection gas is analyzed in a hermetic chamber, and the relationship between the buoyancy lift and the change of temperature is formulated. The experimental results show that the gas pendulum, similar to the solid pendulum and liquid pendulum, can be utilized to sense the acceleration and the tilt angle.

关键词： natural convection accelerometer tilt sensor.

Dense coding scheme using superpositions of Bell-states and its NMR implementation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2005年第1期48卷 57-67页

作者： ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key Laboratory for Quantum information and Measurements, Department of Physics, Tsinghua University, beijing 100084, china center for Quantum information, Tsinghua University, beijing 100084, china Department of Materials Science and Engineering, beijing Normal University, beijing 100875, china Testing and Analytical center, beijing Normal University, beijing 100875, china Department of Physics, beijing Normal University, beijing 100875, china 1. Key Laboratory for Quantum information and Measurements Department of Physics Tsinghua University 100084 Beijing China 2. center for Quantum information Tsinghua University 100084 Beijing China 3. Department of Materials Science and Engineering Beijing Normal University 100875 Beijing China 4. Testing and Analytical center Beijing Normal University 100875 Beijing China 5. Department of Physics Beijing Normal University 100875 Beijing China

Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.

关键词： dense coding, superpositions of Bell-states, generalized Grover's algorithm, nuclear magnetic res-onance, quantum computer.

An efficient algorithm for solving supply chain network equilibria and equivalent supernetwork based traffic network equilibria

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第12期53卷 3264-3274页

作者： XU Meng1 & GAO ZiYou2 1 MOE Key Laboratory for Urban transportation Complex Systems Theory and Technology, beijing Jiaotong University, beijing 100044, china 2 Institute of Systems Science, School of Traffic and transportation, beijing Jiaotong University, beijing 100044, china 1. MOE Key Laboratory for Urban transportation Complex Systems Theory and Technology Beijing Jiaotong University Beijing 100044 China2. Institute of Systems Science School of Traffic and Transportation Beijing Jiaotong University Beijing 100044 China

This paper is concerned with the algorithm of the supply chain network equilibrium model and its equivalent supernetwork based traffic network equilibrium model with elastic demands. Both models are further written as nonlinear complementarity problems. Semismooth least squares reformulations of the complementarity problems are presented and their convergence properties are investigated. Considering the drawbacks of Quasi-Newton method (using the Fischer-Burmeister function), a semi-smooth Levenberg-Marquardt-type method is proposed to solve the problems. Numerical examples show that the Levenberg-Marquardt-type method can solve the supply chain network equilibrium model and its equivalent supernetwork based traffic network equilibrium model significantly, and is more efficient than the Quasi Newton method and the modified projection method. Furthermore, the Levenberg-Marquardt-type method with the equivalent supernetwork based complementarity formulation can be implemented faster than with the supply chain network equilibrium complementarity formulation.

关键词： supply chain networks traffic network equilibrium supernetwork nonlinear complementarity problem Levenberg Marquardt-type method

Integrative inversion of land surface component temperature

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第11期48卷 2011-2019页

作者： FAN Wenjie1 & XU Xiru1,2 1. Institute of Remote Sensing and Geographical information System, Peking University, beijing 100871, china 2. center of Remote Sensing and GIS of beijing Normal University, beijing 100875, china 1. Institute of Remote Sensing and Geographical information System Peking University 100871 Beijing China 2. center of Remote Sensing and GIS of beijing Normal University 100875 Beijing China

In this paper, the row winter wheat was selected as the example to study the com-ponent temperature inversion method of land surface target in detail. The result showed that the structural pattern of row crop can affect the inversion precision of component temperature evi-dently. Choosing appropriate structural pattern of row crop can improve the inversion precision significantly. The iterative method combining inverse matrix was a stable method that was fit for inversing component temperature of land surface target. The result of simulation and field ex-periment showed that the integrative method could remarkably improve the inversion accuracy of the lighted soil surface temperature and the top layer canopy temperature, and enhance inver-sion stability of components temperature. Just two parameters were sufficient for accurate at-mospheric correction of multi-angle and multi-spectral thermal infrared data: atmospheric trans-mittance and the atmospheric upwelling radiance. If the atmospheric parameters and component temperature can be inversed synchronously, the really and truly accurate atmospheric correction can be achieved. The validation using ATSRII data showed that the method was useful.

关键词： components temperature, inverse pattern, atmospheric correction

Some Concepts on Statistical Models of Relating Mechanical Properties to Chemical Composition

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 1998年第2期12卷 84-86页

作者： Jun Wu~(1)) Chaobin Hao~(2)) Yana Wang~(1)) Shiqi Li~(1)) Linjie Yang~(1)) 1) Metallurgy School, UST beijing, beijing 100083, china 2) Chinese Nuclear information center Metallurgy School UST Beijing Beijing 100083 China Chinese Nuclear information center China

Following the basic principle of modem multivariate statistical analysis theory, the description model, prediction model and control model to relate chemical compositions and mechanical properties of steels are introduced. As an example, the total flowchart of components and structure/properties description, prediction and control model for chemical composition and mechanical properties of 20 and A_2 steel are presented.

关键词： mechanical property statistical model prediction description control

RST transforms resistant image watermarking based on centroid and sector-shaped partition

在线全文

学校读者我要写书评

暂无评论

Science china(information Sciences) 2012年第3期55卷 650-662页

作者： ZHAO Yao1,2*, NI RongRong1,2* & ZHU ZhenFeng1,2* 1Institute of information Science, beijing Jiaotong University, beijing 100044, china 2beijing Key Laboratory of Advanced information Science and Network Technology, beijing 100044, china 1. Institute of information Science Beijing Jiaotong University Beijing 100044 China2. Beijing Key Laboratory of Advanced Information Science and Network Technology Beijing 100044 China

A novel digital watermarking scheme featuring centroid-based sectoring is proposed in this paper. To get higher robustness against geometric attacks, such as rotation, scaling, and translation (RST), a delicate synchronization mechanism was developed and incorporated into the proposed approach. During the process of watermark embedding, the original image was partitioned into sectors based on the image centroid. Synchronization information as well as the message bits is then embedded into these sectors. With the help of the centroid-based sectoring and synchronization information, the proposed approach is capable of restoring the correct sectoring even if it has experienced severe geometric distortion. This attribute ensures the correct recovery of embedded watermarks and contributes to the robustness of the proposed scheme. A series of experiments have been conducted to verify the feasibility and effectiveness of the proposed approach. Experimental results show that the proposed scheme possesses good robustness against RST attacks and considerable robustness against other common image processing attacks.

关键词： digital watermarking geometrical transform attacks RST transforms

Precise recognition of warhead and decoy based on components of micro-Doppler frequency curves

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(information Sciences) 2012年第4期55卷 850-856页

作者： GUO KunYi & SHENG XinQing center for Electromagnetic Simulation,School of information and Electronics,beijing Institute of Technology,beijing 100081,china 1. center for Electromagnetic Simulation School of Information and Electronics Beijing Institute of Technology Beijing 100081 China

From the view of electromagnetic scattering,it is indicated that the micro-Doppler (m-D) character-istics of an extended target undergoing micro-motions are actually induced by the change of incident directions of radar *** micro-motions may lead to similar change of incident directions,consequently inducing similar m-D *** tackle this problem,rather than distinguish warhead and decoy directly from m-D characteristics,the frequency components of m-D frequency curves are used as a new characteristic for recognition in this *** get high precision of frequency components estimation,model-based parameter estimation (MBPE) is utilized to extract the m-D frequency curves from *** obtain high accurate simu-lation results,the backscattered signal simulation is conducted by full-wave numerical *** simulation results validate the theoretical analysis and the high performance of the proposed method.

关键词： micro-Doppler(m-D) target recognition time-frequency representation (TFR) model-based pa-rameter estimation (MBPE)

A POSTERIORI ERROR ANALYSIS OF NONCONFORMING METHODS FOR THE EIGENVALUE PROBLEM

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 2009年第3期22卷 495-502页

作者： Youai LiCollege of Computer and information Engineering, beijing Technology and Business University, beijing100048,china. College of Computer and information Engineering Beijing Technology and Business University Beijing 100048 China

This paper extends the unifying theory for a posteriori error analysis of the nonconformingfinite element methods to the second order elliptic eigenvalue *** particular,the authorproposes the a posteriori error estimator for nonconforming methods of the eigenvalue problems andprove its reliability and efficiency based on two assumptions concerning both the weak continuity andthe weak orthogonality of the nonconforming finite element spaces,*** addition,the authorexamines these two assumptions for those nonconforming methods checked in literature for the Laplace,Stokes,and the linear elasticity problems.

关键词： A posteriori error analysis eigenvalue problem nonconforming finite element.