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Recommendation Method for Contrastive Enhancement of Neighborhood information

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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

A variational method for contour tracking via covariance matching

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science china(information sciences) 2012年第11期55卷 2635-2645页

作者： WU YuWei,MA Bo & LI Pei beijing Laboratory of Intelligent information technology,school of Computer science,beijing institute of technology,beijing 100081,china 1. beijing Laboratory of Intelligent information technology School of Computer Science Beijing Institute of Technology Beijing 100081 China

This paper presents a novel formulation for contour *** model the second-order statistics of image regions and perform covariance matching under the variational level set ***,covariance matrix is adopted as a visual object representation for partial differential equation(PDE) based contour ***-Euclidean calculus is used as a covariance distance metric instead of Euclidean distance which is unsuitable for measuring the similarities between covariance matrices,because the matrices typically lie on a non-Euclidean manifold.A novel image energy functional is formulated by minimizing the distance metric between the candidate object region and a given template,and maximizing the one between the background region and the *** corresponding gradient flow is then derived according to a variational approach,enabling partial differential equations(PDEs) based contour *** on several challenging sequences prove the validity of the proposed method.

关键词： contour tracking covariance region descriptor level set Log-Euclidean Riemannian metric

The effects of relative density of metal foams on the stresses and deformation of beam under bending

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Acta Mechanica Sinica 2007年第4期23卷 409-414页

作者： Aiyu Zhu Tianyou Fan Department of Mathematics,school of science,beijing institute of technology,P.O.Box 327,beijing 100081,china Department of Physics,school of science,beijing institute of technology,P.O.Box 327,beijing 100081,china Department of Mathematics School of Science Beijing Institute of Technology P. O. Box 327 Beijing 100081 China Department of Physics School of Science Beijing Institute of Technology P. O. Box 327 Beijing 100081 China

The exact analytic solution of the pure bending beam of metallic foams is given. The effects of relative density of the material on stresses and deformation are revealed with the Triantafillou and Gibson constitutive law （TG model） taken as the analysis basis. Several examples for individual foams are discussed, showing the importance of compressibility of the cellular materials. One of the objects of this study is to generalize Hill＇s solution for incompressible plasticity to the case of compressible plasticity, and a kinematics parameter is brought into the analysis so that the velocity field can be determined.

关键词： Metal foams - Relative density Compressible plasticity Constitutive law - TG model

Human knowledge acquisition from 3D interaction in virtual environments

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science china(information sciences) 2012年第7期55卷 1528-1540页

作者： CHENG Cheng,JIANG Ru & DONG XueMei beijing Laboratory of Intelligent information technology,school of Computer science,beijing institute of technology,beijing 100081,china 1. beijing Laboratory of Intelligent information technology School of Computer Science Beijing Institute of Technology Beijing 100081 China

Recently,virtual environment (VE) based design and planning,which is a kind of interaction intensive computing,has shown great *** users of such systems are specialists or technicians and their 3D interactions with the system embed a great deal of knowledge and ***,how to integrate human knowledge and skills into VE is a great challenge to researchers in the human computer interaction *** paper proposes a method for acquiring user knowledge from *** main ideas and work include,abstracting the interactive process and formalizing the interactive semantics,as well as providing a semantic model of an interactive information repository,from which user interactive processes can be retrieved and all kinds of application logics can be established.A virtual assembly planning system is introduced as an example of a practical application of this *** show that the related models can well capture user knowledge and retrieve the interaction process.

关键词： human computer interaction interactive semantics virtual environment temporal logic virtual manufacturing virtual assembly

Theoretical observation of hexaatomic molecules containing pentacoordinate planar carbon

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science china Chemistry 2008年第11期51卷 1030-1035页

作者： LUO Qiong State Key Laboratory of Explosion science and technology, beijing institute of technology, beijing 100081, china 1. State Key Laboratory of Explosion science and technology Beijing Institute of Technology Beijing 100081 China

The smallest molecules up to date containing a D5h pentacoordinate planar carbon (PPC) atom, CBe5 and CBe54-, are presented by means of ab initio calculations. To gain a better understanding about which electronic factors contribute to their stabilization, natural bond orbital (NBO) analysis and the nucleus independent chemical shifts (NICS) were calculated. The data reported here suggest that D5h CBe5 is σ aromaticity in nature, while in D5h CBe54- π aromaticity is dominating. The classical octet rule is well satisfied in both molecules, and is one of the fundamental reasons to understand the stability of the pentagon structures. The Be5 ring serves as σ donor in D5h CBe5, and π-acceptor in D5h CBe54-. The D5h CBe54- possessing 18 valence electrons with a closed-shell electron configuration is the most plau-sible candidate for experimental detection.

关键词： pentacoordinate planar carbon Be5 ring ab initio

Visualization of protein RecR in Escherichia coli by fluorescent labelling

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Progress in Natural science:Materials International 2009年第11期19卷 1545-1551页

作者： Jiefang Qiu,Xuefeng Pan~* school of Life science,beijing institute of technology,beijing 100081,china [a]school of Life science Beijing Institute of Technology Beijing 100081 China

RecR protein,a functional equivalent of Rad52 in eukaryotes,plays a critical role in the RecF pathway of homologous recombination in Escherichia *** constructing and expressing the recR-yfp hybrid gene,the distribution of the RecR-YFP fusion protein was visualized in *** by fluorescent *** results showed that RecR proteins can be localized predominantly in the nucleoid region of *** measuring the UV resistance of a recR mutant carrying the recR-yfp gene in the plasmid,the expressed RecR-YFP was found to be functional in improving the UV resistance of the recR deficiency strain.

关键词： RecR YFP DNA Repair Homologous recombination E.coli

Raman Scattering and t-Phase Lattice Vibration of 3% (mole fraction) Y_2O_3-ZrO_2

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Journal of Materials science & technology 2004年第5期20卷 485-489页

作者： Xinglun TANG and Xinhua ZHENGschool of Materials science and Engineering, beijing institute of technology, beijing 100081, china Sch. of Mat. Sci. and Eng. Beijing Inst. of Technol. Beijing 100081 China

The Raman spectra of 3% (mole fraction) Y2O3-ZrO2 (3Y) are obtained at different temperature from 77 K to 853 K. The results show that 260 cm-1 Eg and 460 cm-1 Eg modes on the spectra shift toward lower wave number with the increase of temperature; meanwhile, the continuity of the Half Width at Half Maximum (HWHM) and wave number (frequency) of Raman bands are broken and t-phase only partially transforms to m-phase at 523 K. Based on the experimental results, this paper discusses the t-phase lattice vibration of 3Y and presents the images of vibration displacement of six Raman-active modes for t-phase of ZrO2. The analysis indicates that there are diversities existing in the displacement of the atomic vibration of Raman-active modes because of their different symmetries at various temperature, which leads to the different change tendencies of Raman bands. Furthermore, the abrupt changes of some Raman-active modes indicating the atomic displacement are assumed to be the condensations of phonon modes in the t→m phase transition.

关键词： Raman scattering Zirconia Phase transition Condensation of phonon

Jet formation and penetration mechanism of W typed shaped charge

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Acta Mechanica Sinica 2009年第1期25卷 107-120页

作者： Cheng Wang Fenglei Huang Jianguo Ning State Key Laboratory of Explosion science and technology,beijing institute of technology, 100081 beijing, china State Key Laboratory of Explosion science and technology Beijing Institute of Technology 100081 Beijing China

Existing classical shaped charges are well known for their longer jets capable of achieving large hole depth to hole diameter ratios in metallic targets. However, in some situations, there arises demand to obtain 1：1 ratio for hole depth to hole diameter which is beyond normal shaped charges capability. A new variant of shape charge, named W typed shape charge （WSC）, is proposed in this paper, which can meet the demand of 1：1 ratio, and is based on the geometry that can produce annular jets upon proper initiation scheme. In this paper, we present formation and penetration results of WSC based on three different schemes. We also show that not all WSC designs can form annular jets, only annularly initiated WSC, which also fulfils the ＂Internal-External Liners Equal-Impulse＂ criterion, has the capability to form annular jet. The experimental and numerical results show that when the ratio between annular initiation ring diameter and the charge diameter is 0.75, an annular jet is formed, which was also supported by high speed photographs performed in vacuum. 2D numerical simulations are performed with indigenously developed simulation software, where Eulerian approach with multi-material interface tracking algorithm is utilized, to find various mechanisms involved during jet formation process. The calculation results are found in good agreement with the experimental results, indicating that the interface treatment algorithm proposed in this paper can not only deal with large deformation problem, but also depict clearly the variation of materials interface. It is especially suitable for simulation of the process from liner collapse to formation of shaped charge jet.

关键词： WSC Annular jet Interface tracking Numerical simulation

Tuning surface active oxygen of lanthanum oxide via partial dissolution and regrowth of crystallites

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Journal of Natural Gas Chemistry 2011年第5期20卷 483-486页

作者： Zhiming Gao, Huili Li Key Laboratory of Cluster science, Ministry of Education of china Department of Chemistry, school of science, beijing institute of technology, beijing 100081, china Key Laboratory of Cluster science Ministry of Education of China Department of Chemistry School of Science Beijing Institute of Technology Beijing 100081 China

A commercial lanthanum oxide was modified into X%-La2O3 samples via partial dissolution and regrowth of crystallites, wherein the X value denotes the weight percent of the initial metal oxide powder dissolved by nitric acid. BET measurements and TEM observations indicate that the 20%-La2O3 sample has an increased specific surface area, relatively thin and small crystallites in size. TPD/TPR profiles also show that the 20%-La2O3 sample has more surface active oxygen than the 0%-La2O3 sample. Among the four X%-La2O3 samples, the highest activity for methane oxidation was obtained over the 20%-La2O3 sample. Therefore, the present work proves that the method of partial dissolution and regrowth of crystallites are effective to modify surface property of lanthanum oxide.

关键词： solid state reaction surface oxygen crystallite regrowth TPR metal oxide