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500 个结果
  • 简介:从视觉系统对颜色感知分析入手,在原有直方图方法基础上,结合颜色空间分布提出了一种新图像内容检索和索引模型,该模型有效地解决了原有颜色直方图检索方法存在问题.实验结果表明,该模型是可行且有效.

  • 标签: CBIR 亮度空间分布 颜色空间分布
  • 简介:3.1 自然语言理解 自然语言理解是智能信息检索系统基础,即由信息检索系统自动完成对知识获取,3.3 知识获取 拥有知识是智能信息检索系统区别于一般信息检索系统重要标志

  • 标签: 中应用 人工智能技术 信息检索系统
  • 简介:本文从信息素养概念入手,说明文献检索课对大学生信息素养培养重要作用,分析高校信息素养教育现状和问题,提出高校文献检索课创新措施和方法。

  • 标签: 大学生 信息素养 文献检索课
  • 简介:信息检索是当代大学生必备能力之一,是普通高等学校信息素质教育重要体现。本文以商洛学院为例,分析了信息检索课程开设现状及存在问题,强调该课程对当代大学生综合能力培养重要性。最后,根据作者多年教学经验,提出了课程教学改革对策。

  • 标签: 信息检索 人才培养 信息素质教育 课程改革
  • 简介:Lightweightdesignisoneofthedevelopmenttrendsoftheautomobileindustry.AneffectivewaytoachievelightweightautobodiesistouseAHSS(advancedhighstrengthsteel)forthesafetycomponentsofautomobiles.ThisstudyhastakendoorsillreinforcementsmadeofmartensiteAHSSastheobject,andperformedresearchontheAHSSrollformingtechnologiesandprototypedevelopmentoftypicalasymmetricopencomponents.Bymeansoffiniteelementanalysis(FEA)andsimulation,studieshavebeencarriedoutonthespringbackandedgewavedefectsduringAHSSrollforming,andanoptimizedprocessdesignhasbeenachieved.Thegenerationmechanismsofverticalbows,horizontalcambers,twists,pre-punchedholedistortionandcutendflarehavebeenanalyzed,andsolutionstothesedefectshavebeengiven.Inaddition,tesingoftherollformingprocessforAHSShasbeenconductedandtypicalsampleswithrequireddimensionalaccuracyhavebeenmanufactured.Thisstudyhasprovidedtechnicalsupportforthelarge-scaleapplicationofAHSS.

  • 标签: 高强度钢 汽车零部件 技术支持 轻量化设计 轧辊 成形过程
  • 简介:Large-scaleMIMO(multiple-inputmultiple-output)systemswithnumerouslow-powerantennascanprovidebetterperformanceintermsofspectrumefficiency,powersavingandlinkreliabilitythanconventionalMIMO.Forlarge-scaleMIMO,thereareseveraltechnicalissuesthatneedtobepracticallyaddressed(e.g.,pilotpatterndesignandlow-powertransmissiondesign)andtheoreticallyaddressed(e.g.,capacitybound,channelestimation,andpowerallocationstrategies).Inthispaper,weanalyzethesumrateupperboundoflarge-scaleMIMO,investigateitskeytechnologiesincludingchannelestimation,downlinkprecoding,anduplinkdetection.Wealsopresentsomeperspectivesconcerningnewchannelmodelingapproaches,advanceduserschedulingalgorithms,etc.

  • 标签: MIMO技术 多输入多输出 信道估计 模式设计 上行链路 频谱效率
  • 简介:随机地震倒置是geostatistics和从地震记录,井木头,和geostatistics把信息集成到表面下模型以后概率密度功能(PDF)地震倒置技术联合。Markov链蒙特卡罗(MCMC)方法被用来取样以后PDF,表面下模型特征能被分析推断一套以后PDF样品。在这份报纸,我们首先介绍随机地震倒置理论,讨论并且分析四个关键参数:地震数据signal-to-noise比率(S/N),variogram,以后PDF样品数字,和井密度,并且建议这些参数最佳选择。分析结果证明地震数据S/N调整在地震数据影响之间妥协,倒置上geostatistics结果,variogram控制倒置结果光滑,以后PDF样品数字决定统计特征可靠性源于样品,并且很好,密度影响倒置无常。最后,在随机地震倒置之间比较和确定模型基于地震倒置显示随机地震倒置能提供表面下特性更可靠信息

  • 标签: 地震反演理论 关键参数 随机 概率密度函数 优化 地下模型
  • 简介:Inordertoovercomethepoorlocalsearchabilityofgeneticalgorithm,resultinginthebasicgeneticalgorithmistime-consuming,andlowsearchabilityinthelateevolutionary,weusethegraycodinginsteadofbinarycodingatthebeginningofthecoding;weusemulti-pointcrossovertoreplacetheoriginalsingle-pointcrossoveroperation.Finally,theexperimentshowsthattheimprovedgeneticalgorithmnotonlyhasastrongsearchcapability,butalsothestabilityhasbeeneffectivelyimproved.

  • 标签: 改进遗传算法 关键帧提取 局部搜索能力 gray编码 基本遗传算法
  • 简介:DriftmarkedChina-Japantiesinmostpartofthe1990s,accompaniedwithwildswings.Thelastdecadeofthe20thcenturywitnessedthecommemorationofthe20thanniversary(1972-1992)ofdiplomaticnormalization,the50thanniversary(1945-1995)ofthevictoryoftheWarofResistanceAgainstJapaneseAggression,thefuroroverthe"NoWardecision"inJapan,andtheshockwavesfromthereorientationofJapan-U.S.relationshipin1996andtherevisionoftheguidelines

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  • 简介:AbstractMandibular condylar fractures are among the most common facial fractures and some of the most difficult to manage. Opinions about the management of mandibular condylar fractures differ among surgeons. With the implementation of new technology, an increased understanding of fracture management, and better functional and morphological outcomes reported in the literature, open reduction and internal fixation is becoming many surgeons’ preferred choice for the treatment of condylar fractures. Because surgical treatment of such fractures is complex, certain factors must be considered to achieve satisfactory outcomes. In this article, we summarise six key points in the management of mandibular condylar fractures: virtual evaluation of condylar fracture, a suitable surgical approach, good reduction, stable internal fixation, repair of the articular disc, and restoration of the mandibular arch width. We believe that these points will help to improve the prognosis of mandibular condyle fractures.

  • 标签: Mandibular fractures Condylar fractures Template
  • 简介:Densechromiumsesquioxiderefractorieshavewidelybeenusedinthekilnsformakingalkai-freeandanti-alkaliglassfibersduetotheirexcellentre-sistancetomoltenglasses.Densificationsofchromiumsesquioxideduringsinteringcanbeblockedbyevaporationofchromiumtrioxidederivedfromoxidationathightemperature,Inthispaperthemech-anismofsinteringchromiumoxideandtheprocess-ingtechniqueformakingdensechromiumsesquiox-iderefractoriesarediscussed.Aprocessinlaboratoryscaleformakingdensechromiumsesquioxidebricksisdemonstrated.

  • 标签: 制造技术 三氧化二铬 耐火材料