检索结果-南通市图书馆

VSAN:A new visualization method for super-large-scale academic networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第1期18卷 119-137页

作者： Qi LI Xingli WANG Luoyi FU Xinde CAO Xinbing WANG Jing ZHANG Chenghu ZHOU department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200240China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

As a carrier of knowledge,papers have been a popular choice since ancient times for documenting everything from major historical events to breakthroughs in science and *** the booming development of science and technology,the number of papers has been growing *** like the fact that Internet of Things(IoT)allows the world to be connected in a flatter way,how will the network formed by massive academic papers look like?Most existing visualization methods can only handle up to hundreds of thousands of node size,which is much smaller than that of academic networks which are usually composed of millions or even more *** this paper,we are thus motivated to break this scale limit and design a new visualization method particularly for super-large-scale academic networks(VSAN).Nodes can represent papers or authors while the edges means the relation(e.g.,citation,coauthorship)between *** order to comprehensively improve the visualization effect,three levels of optimization are taken into account in the whole design of VSAN in a progressive manner,i.e.,bearing scale,loading speed,and effect of layout *** main contributions are two folded:(1)We design an equivalent segmentation layout method that goes beyond the limit encountered by state-of-the-arts,thus ensuring the possibility of visually revealing the correlations of larger-scale academic entities.(2)We further propose a hierarchical slice loading approach that enables users to observe the visualized graphs of the academic network at both macroscopic and microscopic levels,with the ability to quickly zoom between different *** addition,we propose a“jumping between nebula graphs”method that connects the static pages of many academic graphs and helps users to form a more systematic and comprehensive understanding of various academic *** our methods to three academic paper citation datasets in the AceMap database confirms the visualization scalability of VSAN in t

关键词： academic networks large graph visualization graph layout graph loading

Space-time estimates of the 3D bipolar compressible Navier-Stokes-Poisson system with unequal viscosities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China mathematics 2024年第5期67卷 1059-1084页

作者： Zhigang Wu Weike Wang department of mathematics Donghua UniversityShanghai 201620China School of Mathematical Sciences Shanghai Jiao Tong UniversityShanghai 200240China shanghai Frontier Science Center of Modern Analysis(CMA-shanghai) Shanghai Jiao Tong UniversityShanghai 200240China

The space-time behavior for the Cauchy problem of the 3D compressible bipolar Navier-Stokes-Poisson(BNSP)system with unequal viscosities is *** space-time estimate of the electric field▽φ=▽(-△)^(-1)(n-Zρ)is the most important in deducing generalized Huygens’principle for the BNSP system and it requires proving that the space-time estimate of n-Zρonly contains the diffusion wave due to the singularity of the operator▽(-△)^(-1).A suitable linear combination of unknowns reformulating the original system into two small subsystems for the special case(with equal viscosities)in Wu and Wang(2017)is crucial for both linear analysis and nonlinear estimates,especially for the space-time estimate of▽φ.However,the benefits from this reformulation will no longer exist in general ***,we study an 8×8 Green’s matrix *** importantly,each entry in Green’s matrix contains wave operators in the low-frequency part,which will generally produce Huygens’wave;as a result,one cannot achieve the space-time estimate of n-Zρthat only contains the diffusion wave as *** overcome this difficulty by taking a more detailed spectral analysis and developing new estimates arising from subtle cancellations in Green’s function.

关键词： Green's function bipolar Navier-Stokes-Poisson system unequal viscosities

同方期刊数据库

Design, modeling, and evaluation of parallel continuum robots: A survey

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第3期67卷 673-695页

作者： CHEN GenLiang TANG ShuJie DUAN XuYang WANG Hao Meta Robotics Institute Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical Systems and Vibration Shanghai Jiao Tong UniversityShanghai 200240China shanghai Key Laboratory of Digital Manufacturing for Thin-Walled Structures Shanghai Jiao Tong UniversityShanghai 200240China

Parallel continuum robots(PCRs) have attracted increasing attention in the robotics community due to their simplicity in structure,inherence with compliance, and easiness of realization. Over the past decade, a variety of novel designs have been reported to enrich their diversity. However, there is a lack of systematic review of these emerging robots. To this end, this paper conducts a comprehensive survey on the mechanism design, kinetostatic modeling and analysis, and performance evaluation. For these robots, kinetostatic modeling plays a fundamental role throughout the design, analysis, and control stages. A systematic review of the existing approaches for kinetostatic modeling and analysis is provided, and a comparison is made to distinguish their differences. As well, a classification is made according to the characteristics of structure and actuation. In addition, performance evaluation on the workspace, stability, and singularity is also overviewed. Finally, the scenarios of potential applications are elaborated, and future research prospects are discussed. We believe that the information provided in this paper will be particularly useful for those who are interested in PCRs.

关键词： parallel continuum robots classification kinetostatic modeling performance evaluation

Velocity-Incorporated Wear Model of Rolling Guide Shoe Material Selection

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第3期37卷 118-135页

作者： Longye Chen Lingyu Yan Chengliang Liu Zhinan Zhang School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

To ensure an accurate selection of rolling guide shoe materials,an analysis of the intricate relationship between linear speed and wear is *** element simulations and experimental measurements are employed to evaluate four distinct types of materials:polyurethane,rubber,polytetrafluoroethylene(PTFE),and *** speed-index of each material is measured,serving as a preparation for subsequent ***,the velocity-wear factor is determined,providing insights into the resilience and durability of the material across varying ***,a wear model tailored specifically for viscoelastic bodies is explored,which is pivotal in understanding the wear mechanisms within the *** this model,wear predictions are made under higher speed conditions,facilitating the choice of material for rolling guide *** validate the accuracy of the model,the predicted degree of wear is compared with experimental data,ensuring its alignment with both theoretical principles and real-world *** comprehensive analysis has verified the effectiveness of the model in the selection of materials under high-speed conditions,thereby offering confidence in its reliability and ensuring optimal performance.

关键词： Archard model Wear model Speed-index Wear prediction

Numerical simulation study on the hygrothermal performance of building exterior walls under dynamic wind-driven rain condition

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Building Simulation 2024年第2期17卷 207-221页

作者： Xing Hu Huibo Zhang Hui Yu School of Design Shanghai Jiao Tong UniversityShanghai200240China

Wind-driven rain(WDR)has a significant influence on the hygrothermal performance,durability,and energy consumption of building *** calculation of WDR loads using semi-empirical models has been incorporated into the boundary conditions of coupled heat and moisture transfer ***,prior research often relied on fixed WDR absorption ratio,which fail to accurately capture the water absorption characteristics of porous building materials under rainfall ***,this study aims to investigate the coupled heat and moisture transfer of exterior walls under dynamic WDR boundary conditions,utilizing an empirically obtained WDR absorption ratio model based on field *** developed coupled heat and moisture transfer model is validated against the HAMSTAD *** findings reveal that the total WDR flux calculated with the dynamic WDR boundary is lower than that obtained with the fixed WDR boundary,with greater disparities observed in orientations experiencing higher WDR *** variations in moisture flow significantly impact the surface temperature and relative humidity of the walls,influencing the calculation of cooling and heating loads by different *** to the transient heat transfer model,the coupled heat and moisture transfer model incorporating dynamic WDR boundary exhibits maximum increases of 17.6%and 16.2%in cooling and heating loads,*** dynamic WDR boundary conditions provide more precise numerical values for surface moisture flux,offering valuable insights for the thermal design of building enclosures and load calculations for HVAC systems.

关键词： wind-driven rain building component hygrothermal model transient simulation cooling and heating loads

A Novel Method for Forecasting Freak Wave Occurrence in A Short Crested Coastal Sea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第1期38卷 104-116页

作者： WANG Ying-guang State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Ocean and Civil Engineering Shanghai Jiao Tong UniversityShanghai 200240China

In order to forecast the distribution of crest amplitudes and the occurrence of freak waves in a short crested coastal sea,a novel transformed linear simulation method is initially proposed in this paper.A Hermite transformation model expressed as a monotonic cubic polynomial serves as the foundation for the novel simulation *** wave crest amplitude exceedance probabilities of two sea states-one with a directional wave spectrum based on the measured wave elevation data at the Yura coast and the other with a typical directional JONSWAP wave spectrum-have been predicted using the novel simulation method that has been *** likelihood that a particular critical wave crest amplitude will be exceeded is directly correlated with the probability that freak waves will *** is shown that the novel simulation approach suggested can provide predictions that are more precise than those obtained from the Rayleigh crest amplitude distribution model,the Jahns and Wheeler crest amplitude distribution model,or the conventional linear simulation *** study also demonstrated that the nonlinear simulation method is less effective than the novel simulation method in terms of efficiency.

关键词： wave crest amplitude freak waves short crested sea transformed linear simulation

Divergence angle consideration in energy spread measurement for high-quality relativistic electron beam in laser wakefield acceleration

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第6期33卷 363-368页

作者：卢光伟李曜均胡曦辰陈思宇徐豪祝铭阳闫文超陈黎明 Key Laboratory for Laser Plasmas of Ministry of Education Shanghai Jiao Tong UniversityShanghai 200240China IFSA Collaborative Innovation Center Shanghai Jiao Tong UniversityShanghai 200240China

The thorough exploration of the transverse quality represented by divergence angle has been lacking yet in the energy spread measurement of the relativistic electron beam for laser wakefield acceleration(LWFA). In this work, we fill this gap by numerical simulations based on the experimental data, which indicate that in a C-shape magnet, magnetic field possesses the beam focusing effect, considering that the divergence angle will result in an increase in the full width at half maxima(FWHM) of the electron density distribution in a uniformly isotropic manner, while the length-to-width ratio decreases. This indicates that the energy spread obtained from the electron deflection distance is smaller than the actual value, regardless of the divergence angle. A promising and efficient way to accurately correct the value is presented by considering the divergence angle(for instance, for an electron beam with a length-to-width ratio of 1.12, the energy spread correct from 1.2% to 1.5%), providing a reference for developing the high-quality electron beam source.

关键词： relativistic electron beams acceleration by laser–plasma interactions finite element analysis

High-throughput calculations combining machine learning to investigate the corrosion properties of binary Mg alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第4期12卷 1406-1418页

作者： Yaowei Wang Tian Xie Qingli Tang Mingxu Wang Tao Ying Hong Zhu Xiaoqin Zeng university of Michigan-shanghai jiao tong university Joint Institute Shanghai Jiao Tong University200240ShanghaiChina State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai200240China

Magnesium(Mg)alloys have shown great prospects as both structural and biomedical materials,while poor corrosion resistance limits their further *** this work,to avoid the time-consuming and laborious experiment trial,a high-throughput computational strategy based on first-principles calculations is designed for screening corrosion-resistant binary Mg alloy with intermetallics,from both the thermodynamic and kinetic *** stable binary Mg intermetallics with low equilibrium potential difference with respect to the Mg matrix are firstly ***,the hydrogen adsorption energies on the surfaces of these Mg intermetallics are calculated,and the corrosion exchange current density is further calculated by a hydrogen evolution reaction(HER)kinetic *** intermetallics,e.g.Y_(3)Mg,Y_(2)Mg and La_(5)Mg,are identified to be promising intermetallics which might effectively hinder the cathodic ***,machine learning(ML)models are developed to predict Mg intermetallics with proper hydrogen adsorption energy employing work function(W_(f))and weighted first ionization energy(WFIE).The generalization of the ML models is tested on five new binary Mg intermetallics with the average root mean square error(RMSE)of 0.11 *** study not only predicts some promising binary Mg intermetallics which may suppress the galvanic corrosion,but also provides a high-throughput screening strategy and ML models for the design of corrosion-resistant alloy,which can be extended to ternary Mg alloys or other alloy systems.

关键词： Mg intermetallics Corrosion property High-throughput Density functional theory Machine learning

Automatic bug assignments without texts: a study

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第4期18卷 211-213页

作者： Zexuan LI Kaixin HUANG department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

1 Introduction Automatic bug assignment has been well-studied in the past *** textual bug reports usually describe the buggy phenomena and potential causes,engineers highly depend on these reports to fix ***,researchers spend much effort on processing bug reports,aiming for obtaining key information and/or clues for reproducing bugs,analyzing their root causes,assigning them to developers/maintainers,and fixing these ***,our previous research[1]reveals that noises in texts bring adverse impacts to automatic bug assignments unexpectedly,mainly due to insufficiency of classical Natural Language Processing(NLP)techniques.

关键词： bug assignment maintain