检索结果-南通市图书馆

Two kinds of average approximation accuracy

在线全文

学校读者我要写书评

暂无评论

CAAI Transactions on Intelligence Technology 2024年第2期9卷 481-490页

作者： Qingzhao Kong Wanting Wang Dongxiao zhang Wenbin zhang Department of Science Jimei UniversityXiamenChina Digital Fujian Big Data Modeling and Intelligent Computing Institute Jimei UniversityXiamenChina Department of Computer Science Michigan Technological UniversityHoughtonMichiganUSA

Rough set theory places great importance on approximation accuracy,which is used to gauge how well a rough set model describes a target ***,traditional approximation accuracy has limitations since it varies with changes in the target concept and cannot evaluate the overall descriptive ability of a rough set *** overcome this,two types of average approximation accuracy that objectively assess a rough set model’s ability to approximate all information granules is *** first is the relative average approximation accuracy,which is based on all sets in the universe and has several basic *** second is the absolute average approximation accuracy,which is based on undefinable sets and has yielded significant *** also explore the relationship between these two types of average approximation ***,the average approximation accuracy has practical applications in addressing missing attribute values in incomplete information tables.

关键词： rough sets rough set theory

Mo SILTCIDE SYNTHISIS BY DUAL ION BEAM DEPOSITION

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

Acta Metallurgica Sinica(English Letters) 2002年第2期15卷 187-190页

作者： T.H. zhang, Z.Z. Yi, X. Y. Wu, S.j. zhang, Y. G. Wu, X. zhang, H.X. zhang, A.D. Liu and X.j. zhang Key Laboratory for Radiation Beam Technology and Material Modification, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing Radiatio

Mo silicides Mo_5Si_3 with high quality were prepared using ion beamdeposition equipment with two Filter Metal Vacuum Are Deposition (FMEVAD). When the number ofalternant deposition times was 198, total thickness of the coating is 40nm. The coatings withdroplet free can be readily obtained, so the surface is smooth. TEM observation shows that Mo and Sialternant deposition coating is compact structure. The fine Mo silicide grains densely distributedin the coating. The coating adherence on silicon is excellent.

关键词： Mo silicide ion alternant deposition silicon

Controlling secondary flow in high-lift low-pressure turbine using boundary-layer slot suction

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2024年第3期37卷 21-33页

作者： Xiao QU Liunan LI Yingjie zhang Xingen LU junqiang ZHU Yanfeng zhang School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100190China

The design of high-lift Low-Pressure Turbines(LPTs)causes the separation of the boundary layer on the suction side of the blade and leads to a strong secondary *** present study aims to minimize secondary losses through endwall slot suction and incoming wakes in a front-loaded high-lift LPT cascade with Zweifel of 1.58 under low Reynolds number of *** slotted schemes for the boundary layer of the endwall were designed(Plan A and Plan B),and the effects of suction mass flow on secondary flow were *** underlying physics of the endwall boundary layer of the suction and secondary flow under unsteady wakes was *** results show that slot suction at the endwall boundary layer can significantly suppress the secondary flow by removing low-momentum *** A and B significantly reduced the secondary kinetic energy by 44.2%and 36.9%,respectively,compared with the baseline cascade at the suction mass flow ratios of 1%.With an increase in the mass flow ratio of suction,the secondary flow was gradually reduced in both Plans A and *** is more beneficial to control the secondary flow to destroy the intersection of the pressure side and suction side of the horseshoe vortex before it develops into a passage *** unsteady wakes,the combined effects of incoming wakes and endwall boundary layer suction can further suppress the secondary flow at the suction mass flow ratios of 2%for Plan A,because the positive and negative vorticity inside upstream wakes accelerated the mixing of the main flow and secondary flow and thus increased the energy of secondary vortices.

关键词： Low-pressure turbine Secondary flow Flow control Boundary-layer suction Incoming wake

在线全文

学校读者我要写书评

暂无评论

关键基础设施及其安全管理

管理科学学报 2009年第6期12卷 107-115页

作者：刘晓张隆飙 zhang W j Tu Y L 上海交通大学机械与动力学院上海200240 东北大学工商管理学院沈阳110004 萨斯客彻温省大学机械工程学院加拿大卡尔加里大学机械与制造工程学院加拿大

关键基础设施(CI)系统是复杂的、高度相互依存的、网络化的社会—技术系统,一旦系统被中断或者被破坏,将会对国民健康、国土安全、经济稳定以及政府的正常运转等产生重大的影响.主要研究关键基础设施及其安全管理过程中的若干问题,对CI... 详细信息

关键基础设施(CI)系统是复杂的、高度相互依存的、网络化的社会—技术系统,一旦系统被中断或者被破坏,将会对国民健康、国土安全、经济稳定以及政府的正常运转等产生重大的影响.主要研究关键基础设施及其安全管理过程中的若干问题,对CI的特点进行了分析和总结,建立了网络化CI系统的体系结构,并利用视图模型来描述系统,同时还给出了灾难处理的一般过程.最后,进一步探讨了如何使用系统工程的方法来分析和模拟网络化CI系统的运行方式、潜在的薄弱环节以及改进这些薄弱环节的实施方法.

关键词：关键基础设施社会一技术系统建模体系结构

在线全文

学校读者我要写书评

暂无评论

相关性分析在体育管理研究中的应用

上海体育学院学报 2016年第3期40卷 1-9,39页

作者： jerry j.Wang james j.zhang james W.Du 张轶美国佐治亚大学国际体育管理研究中心佐治亚州雅典30602 美国天普大学福克斯商学院宾夕法尼亚州费城19122 上海大学体育学院上海200444

采用文献资料和案例分析法,对基础相关性分析和回归分析在体育管理研究中的应用进行研究。基于相互依赖型和依存型2种关系的阐述,结合体育管理实证研究案例,讨论了在研究设计和分析过程中涉及的研究目标、定义、潜在机制以及关键实证假... 详细信息

采用文献资料和案例分析法,对基础相关性分析和回归分析在体育管理研究中的应用进行研究。基于相互依赖型和依存型2种关系的阐述,结合体育管理实证研究案例,讨论了在研究设计和分析过程中涉及的研究目标、定义、潜在机制以及关键实证假设等问题,并重点介绍依赖型分析方法(如双变量相关、简单线性回归、多元线性回归、多项式回归、逻辑回归、判别函数分析)。

关键词：体育管理相关性分析回归分析

Analysis method and experimental study of ice accumulation detection signal based on Lamb waves

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2024年第8期37卷 388-403页

作者： Yanxin zhang Hongjian zhang Xian YI Binrui WU Xianlei GUAN jianjun XIONG Key Laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development CenterMianyang 621000China State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyang 621000China

A quantitative identification method for in-flight icing has the capability to significantly enhance the safety of aircraft *** guided waves have the unique advantage of detecting icing in a relatively large area,but quantitative identification of ice layers is a *** this paper,a quantitative identification method of ice accumulation based on ultrasonic guided waves is ***,a simulation model for the wave dynamics of piezoelectric coupling in three dimensions is established to analyze the propagation characteristics of Lamb waves in a structure consisting of an aluminum plate and an ice *** wavelet transform method is utilized to extract the Time of Flight(ToF)or Time of Delay(ToD)of S_(0)/B_(1) mode waves,which serves as a characteristic parameter to precisely determine and assess the level of ice ***,an experimental system is developed to evaluate the feasibility of Lamb waves-based icing real-time detection in the presence of spray ***,a combination of the Hampel median filter and the moving average filter is developed to analyze ToF/ToD *** simulation results reveal a positive correlation between geometric dimensions(length,width,thickness)of the ice layer and ToF/ToD of B1 mode waves,indicating their potential as indicators for quantifying ice *** results of real-time icing detection indicate that ToF/ToD will reach greater peak values with the growth of the arbitrary-shaped ice layer until saturation to effectively predict the simulation *** study lays a foundation for the practical application of quantitative icing detection via ultrasonic guided waves.

关键词： Ice Ice accumulation Ultrasonic sensor Ultrasonic guided wave Lamb wave Wavelet transform

NEAR RAPID DIRECTIONAL SOLIDIFICATION AND ITS SUPERFINE MICROSTRUCTURE

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

Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 497-502页

作者： H.Z. Fu X.G. Gen j.G. Li and j.zhang(State Key Lab.of Solidification Processing, Northwestern Polytechnical University,Xi’an 710072,China ) Northwestern Polytechnical Univ Xi'an China

This paper briefly reviews the recent research on the near rapid directional solidification and microstructure superfining. The morphology transitions and the corresponding mechanical properties are presented. The critical velocities relevant to the morphology transitions are comprehensively given. Meanwhile the solidification characteristics near absolute stability limit are *** can be clearly seen that the superfine microstructures possess extremely better properties compared with the conventional microstructures.

关键词： near rapid directional solidification,superfine microstructure,morphology transition mechanical property

体育管理研究与理论构建、检验中的核心问题——体育管理学研究设计、测量和分析系列

在线全文

学校读者我要写书评

暂无评论

上海体育学院学报 2016年第1期40卷 4-11页

作者： james j.zhang james W.Du jerry j.Wang 张轶美国佐治亚大学国际体育管理研究中心佐治亚州雅典30602 美国天普大学福克斯商学院宾夕法尼亚州费城19122 上海大学体育学院上海200444

为引导青年学者开展高水平体育管理研究,本系列论文(由6篇文章组成,未来2年内陆续向读者呈现)旨在阐明中高级科学研究理念、研究流程、设计应用、测量方法、数据分析,及它们的集成性和在体育管理理论检验与发展中的功能。首篇将综述体... 详细信息

为引导青年学者开展高水平体育管理研究,本系列论文(由6篇文章组成,未来2年内陆续向读者呈现)旨在阐明中高级科学研究理念、研究流程、设计应用、测量方法、数据分析,及它们的集成性和在体育管理理论检验与发展中的功能。首篇将综述体育产业发展的背景信息,指出日益增长的科学研究需求和激烈的学术竞争环境,并讨论在体育管理研究与理论构建、检验中的核心问题。最后,揭示系列拣选内容所遵循的基本逻辑。

关键词：体育管理科学研究理论框架测量评价市场分析设计

Existence of a-Cores for Games Without Compact Assumptions

在线全文

学校读者我要写书评

暂无评论

journal of the Operations Research Society of China 2024年第2期12卷 520-527页

作者： Hai-Qun zhang School of International Economics and Trade Shanghai Lixin University of Accounting and Fin Shanghai201209China

Following the representation of Kajii(j Econ Theory 56:194-205,1992),we provide some existence theorems ofα-cores for games without ordered preferences and compact *** applications,we obtain some existence results of... 详细信息

关键词： α-Core Existence Preference Noncompactness