检索结果-南通市图书馆

Detecting Communities in K-Partite K-Uniform (Hyper)Networks

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2011年第5期26卷 778-791页

作者：刘欣 tsuyoshi Murata Department of Computer Science Tokyo Institute of Technology

In social tagging systems such as Delicious and Flickr,users collaboratively manage tags to annotate ***,a social tagging system can be modeled as a （user,tag,resource） hypernetwork,where there are three different types of nodes,namely users,resources and tags,and each hyperedge has three end nodes,connecting a user,a resource and a tag that the user employs to annotate the *** how can we automatically cluster related users,resources and tags,respectively？ This is a problem of community detection in a 3-partite,3-uniform *** generally,given a K-partite K-uniform （hyper）network,where each （hyper）edge is a K-tuple composed of nodes of K different types,how can we automatically detect communities for nodes of different types？ In this paper,by turning this problem into a problem of finding an efficient compression of the （hyper）network＇s structure,we propose a quality function for measuring the goodness of partitions of a K-partite K-uniform （hyper）network into communities,and develop a fast community detection method based on *** method overcomes the limitations of state of the art techniques and has several desired properties such as comprehensive,parameter-free,and *** compare our method with existing methods in both synthetic and real-world datasets.

关键词： community detection bipartite graph tripartite hypergraph clustering social tagging

Evaluation of high-temperature tensile behavior for metal foils by a novel resistance heating assisted tensile testing system using samples with optimized structures

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第35期94卷 216-229页

作者： Qiu Zheng tsuyoshi Furushima Department of Mechanical and Biofunctional Systems Institute of Industrial ScienceThe University of Tokyo4-6-1 KomabaMeguro 153-8505TokyoJapan

To evaluate the tensile behavior of metal foils by resistance heating(RH)assisted tensile testing system accurately,this study proposed to embed a digital image correlation(DIC)system with laser speckles for the measurement of full-field strain ***,the sample structures were optimized to achieve uniform temperature and strain *** infrared camera was used to monitor the temperature *** samples instead of dog-bone shaped samples were proposed.A model for calculating the temperature distribution was established to optimize the sample *** parameters that influence the temperature distribution and tensile behavior were *** results,compared to the strain measured by a non-contact extensometer,the maximum deviation of the strain measured by DIC was less than 6%when the nominal strain was larger than *** is confirmed that the proposed tensile testing system is reliable for measuring the temperature and full-field strain *** shape influenced temperature distributions of smaller samples while it almost had no influence on the temperature distributions of larger *** temperature difference was not affected by the material type but by the sample *** proposed rectangular shape was validated to be feasible for RH assisted tensile *** sample length was successfully optimized for a more uniform temperature distribution by the established *** the tensile deformation was not influenced by the sample shape,the temperature distribution resulted in a non-uniform strain distribution before achieving ultimate tensile *** effective sample length between two clamping jigs contributed to a more uniform temperature distribution and material deformation.A more accurate evaluation of high-temperature tensile behavior for metal foils can be achieved by the proposed RH assisted tensile testing system using rectangular samples with an optimized structure.

关键词： High temperature Metal foil Resistance heating Sample structure Tensile behavior

Evaluation of Important Factors Affecting Quench Distortion of Carburized Hypoid Gear with Shaft by Using Computer Simulation Methods

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5期25卷 480-485页

作者： tsuyoshi Sugimoto Youichi Watanabe Nissan Motor Co. Ltd. 6-1 Daikoku-cho Tsurumi Yokohama JapanNissan Motor Co. Ltd. 6-1 Daikoku-cho Tsurumi Yokohama Japan

To minimize quenching distortion and dispersion, carburizing and quenching process conditions must be optimized; this includes the parts racking design used for quenching. We investigated some factors affecting carburized quenching distortion with an experiment using a hypoid gear having a shaft and with numerical simulation methods. The experimental results and those obtained from simulation were generally in agreement. Focusing on the surface temperature distribution in the gear, we studied quenching distortion characteristics in terms of changes in tooth profile and helix deviation. In our experiments, distortions occur during quenching in 373 K oil after austenitized temperature treatments conducted with various attitudes. We calculated the distortions by simulating the carburized oil-quenching process for the hypoid gear. Our results show large differences between the cooling rates of the tooth toe, middle section, and heel edges, and these greatly influence the change in tooth profile and helix deviation. We found that reducing the differences in temperatures on the gear surfaces during quenching is most important for minimizing the quench distortion of the hypoid gear.

关键词：淬火变形螺旋偏差外形偏差冷却曲线传热系数准双曲面齿轮

Thermal Analysis of Resin Composites with Ellipsoidal Filler Considering Thermal Boundary Resistance

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2016年第5期25卷 424-430页

作者： Yusuke Asakuma tsuyoshi Yamamoto Department of Chemical Engineering University of Hyogo Department of Chemical Engineering Kyushu University

The effective thermal conductivity of composites with ellipsoidal fillers is analyzed by using a homogenization method that is able to represent the microstructure *** this study,various parameters such as the volume fraction,shape,and distribution of the filler are quantitatively estimated to understand the mechanisms of heat transfer in the ***,thermal boundary resistance between resin and filler is important for obtaining composites with higher thermal ***,the anisotropy of the effective thermal conductivity arises from contact between filler in the case of ellipsoidal filler and produces lower thermal ***,the filler network and thermal resistance are essential for the heat transfer in composites because the path of thermal conduction is improved by contact between neighboring filler particles.

关键词： effective thermal conductivity homogenization method multiscale analysis composite.

Continuous observation of twinning and dynamic recrystallization in ZM21 magnesium alloy tubes during locally heated dieless drawing

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第3期10卷 791-805页

作者： Peihua Du Shusaku Furusawa tsuyoshi Furushima Department of Mechanical and Biofunctional Systems Institute of Industrial ScienceThe University of Tokyo4-6-1KomabaMeguroTokyo 153-8505Japan

Compared to cold drawing,dieless drawing has shown great potential for manufacturing biodegradable Mg alloy microtubes due to the large reduction in area acquired in a single ***,owing to the local heating and local deformation,the deformation mechanism during dieless drawing is not clear,and thus causing difficulties in controlling the microstructure of dieless drawn *** the purpose of acquiring a desired *** this study the deformation mechanism of ZM21 Mg alloy tube was clarified by conducting continuous observation of the microstructural evolution during dieless *** results show that both SRX and DRX occurred during dieless *** occurred before the plastic deformation to soften dieless drawn *** increase of feeding speed,the deformation mechanism changed accordingly:(1) At the low-speed of 0.02 mm/s,the deformation mechanism was dominated by twin-slip sliding,during which {10-12} tension twins were generated inside grains to accommodate the plastic deformation by changing the crystal orientation.(2) At the intermediate-speed of 2 mm/s,a twin-DRX process related to {10-12} tension twin was observed,which was characterized by the generation of abundant {10-12} tension twins and the evolution of misorientation angle of {10-12} tension ***,the transformation from twin-DRX to CDRX can be observed at the late stage of plastic deformation,which was attributed to the inhomogeneous conditions of dieless drawing.(3) At the high-speed of 5 mm/s,a CDRX process was observed,during which grain boundary sliding and grain tilting were observed,in addition to the gradual rotation of *** results show that during dieless drawing,DRX is not only a temperature-dependent phenomenon,but also influenced by the variation of feeding speed.

关键词： Dieless drawing Inhomogeneous condition Twining Dynamic recrystallization Microstructure evolution Magnesium alloy Twinning

Imbricate structure of the Otakeyama area, Okayama Permian Yoshii Group in the Prefecture, southwest Japan

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2015年第1期9卷 152-163页

作者： tsuyoshi ITO Atsushi MATSUOKA State Key Laboratory of Geo-processes and Mineral Resources China University of Geosciences Wuhan 430074 China Department of Geology Faculty of Science Niigata University Niigata 950-2181 Japan

The Yoshii Group of the Akiyoshi terrane is distributed over the Otakeyama area, Okayama Prefecture, southwest Japan. The Yoshii Group is composed of siliceous rocks and clastics, comprising chert-clastic sequences. The Yoshii Group is divided into four structural units （Units Ot 1, Ot 2, Ot 3, and Ot 4） in structurally ascending order. Lithological similarities and radiolarian age suggest that these units exhibit almost identical ocean plate stratigraphy. These units are structurally-repeated to form an imbricate structure. This structure was possibly formed by off-scrape accretion at a toe of an accretionary complex. Additionally, a review of previous studies indicates that an imbricate structure is common in the Akiyoshi terrane. The presence of an imbricate structure in the Akiyoshi terrane, Permian accretionary complex, indicates the possibility that a specific horizon of Permian pelagic sequences acted as a drcollement zone.

关键词： accretionary complex imbricate structure,Permian radiolafia Yoshii Group Okayama Prefecture,southwest Japan

Effect of microstructure on outer surface roughening of magnesium alloy tubes in die-less mandrel drawing

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第10期10卷 2730-2744页

作者： Takuma Kishimoto Peihua Du tsuyoshi Furushima Department of Mechanical and Biofunctional Systems Institute of Industrial ScienceThe University of Tokyo4-6-1 KomabaMeguroTokyo 153-8505Japan

The crystal orientation and outer surface roughening of magnesium alloy tubes were evaluated to clarify the effect of the mandrel on the microstructure and outer surface roughness in die-less mandrel drawing. Locally heated ZM21 tubes with an outer diameter of 6.0 mm and an inner diameter of 3.8 mm were drawn with and without a mandrel. The outer surface roughness and crystal orientation were evaluated in the same measurement area. The results indicated that the outer surface becomes rougher in the die-less mandrel drawing than in die-less drawing for a given outer circumferential strain. The outer surface roughness developed when there was large difference in the pyramidal slip system Schmid factor. Therefore, the slip deformation of the pyramidal slip system seems to be mainly responsible for the outer surface roughening in the die-less mandrel drawing. Furthermore, the crystal grain with the {2110} crystal plane vertical to the normal direction of outer surface had a larger Schmid factor than the other crystal grains. The large number of crystal grains with the {2110} crystal plane in the die-less mandrel drawing is one of the reasons that the outer surface roughness develops more in the die-less mandrel drawing than in die-less drawing for a given outer circumferential strain. These results will contribute significantly to the development of fabrication process of the microtube with high surface quality, which prevents rapid corrosion of biomedical applications.

关键词： Tube forming Die-less drawing Surface roughness Crystal plasticity Magnesium alloy Electron backscatter diffraction

Characteristic and Mechanism of Pressure Fluctuation Caused by Self-Induced Oscillation of Supersonic Impinging Jet

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2013年第2期22卷 123-127页

作者： tsuyoshi Yasunobu Yumiko Otobe Hideo Kashimura Department of Control & Information Systems Engineering Kitakyushu College of Technology

When the underexpanded supersonic jet impinges on the obstacle, it is well known that the self-induced flow os- cillation occurs. This oscillation depends on the pressure ratio in the flowfield, the position of an obstacle and is related with the noise problems of aeronautical and other industrial engineering. The characteristic and the mechanism of self-induced flow oscillation, have to be clarified to control various noise problems. But, it seems that the characteristics of the oscillated flowfield and the mechanism of an oscillation have to be more cleared to control the oscillation. This paper aims to clarify the effect of the pressure ratio and the obstacle position and the mechanism of self-induced flow oscillation by numerical analysis and experiment, when the underexpanded su- personic jet impinges on the cylindrical body. From the result of this study, it is clear that occurrence of the self-induced flow osciUation depends on the pressure balance in the flowfield.

关键词： Supersonic Jet Mach Disk Barrel Shock Flow Oscillation Flow Visualization Numerical Analysis

Effect of Plate Position and Size for Self-Induced Flow Oscillation of Underexpanded Supersonic Jet Impinging on Perpendicular Plate

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第3期20卷 238-241页

作者： tsuyoshi Yasunobu Yumiko Otobe Hideo Kashimura Department of Control & Information Systems Engineering Kitakyushu College of Technology Sii Kokuraminami-ku Kitakyushu-shiFukuoka 802-0985 Japan

When the underexpanded supersonic jet impinges on the obstacle, it is well known that the self-induced flow oscillation occurs at the specific condition of the pressure ratio in the flowfield, the position of an obstacle and so on. This oscillation is related with the noise problems of aeronautical and other industrial engineering so that the characteristic and the mechanism of self-induced flow oscillation have to be cleared to control the various noise problems. But, it seems that the characteristics of the oscillated flowfield and the mechanism of oscillation have to be more clear to control the oscillation. This paper aims to clarify the effect of the plate position and the width for the self-induced flow oscillation of an underexpanded supersonic jet impinging on the perpendicular plate by the experiment and the numerical analysis. From the results, it is clear that the occurring domain of the self-induced flow oscillation and its dimension strongly depend on the plate position and the width.

关键词： Compressible Flow Supersonic Jet Mach Disk Barrel Shock Flow Oscillation