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119 个结果
  • 简介:Inthispaper,wegivethesensitivityanalysesbytwoapproachesforL,D,UinfactorizationA=LDUofgeneralperturbationsinAwhichsufficientlysmallinnorm.Bythematrix-vectorequationapproach,wederivethesharpcoaitionnumberforL,DandUfactors.Bythematrixequationapproachwederivecorrespondingconditionestimates.WhenAisasymmetricmatrix,thecorrespondingresultscanbeobtainedforLDLTfactorization.

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  • 简介:Inasystem,Everycomponenthasitsuniquepositionwithinsystemanditsuniquefailurecharacteristics.Whenacomponent'sreliabilityischanged,itseffectonsystemreliabilityisnotequal.Componentreliabilitysensitivityisameasureofeffectonsystemreliabilitywhileacomponent'sreliabilityischanged.Inthispaper,thedefinitionandrelativematrixofcomponentreliabilitysensitivityisproposed,andsomeoftheircharacteristicsareanalyzed.Allthesewillhelpustoanalyseorimprovethesystemreliability.

  • 标签: 灵敏度分析 可靠性 关系矩阵 系统组成
  • 简介:为高敏感的磁化大小(vibrating-sampie磁强计,轮流出现的坡度磁强计,和SQUID磁强计)的三台很普通的仪器被描述,他们的限制敏感被讨论。各个的优点和劣势被描述。用微机器的力量察觉者的磁强计简短被提及。

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  • 简介:Thepaperdescribedthreemethodsofscalingthebondportfolioprice.Theywereduration,convexityandtimevalue.FromtheprincipleofNo-arbitrage,therewasoneandonlyonerelationshipofduration,convexityandtimevalue.ItchosethreecorporationbondsofChinaandanalyzedtheriskoftwoinvestmentstrategies.

  • 标签: 风险分析 持续时间 凸性 时间价值 证券市场
  • 简介:Inordertogiveacompleteandaccuratedescriptionaboutthesensitivityofefficientportfoliostochangesinassets'expectedreturns,variancesandcovariances,thejointeffectofestimationerrorsinmeans,variancesandcovariancesontheefficientportfolio'sweightsisinvestigatedinthispaper.Itisprovedthattheefficientportfolio'scompositionisaLipschitzcontinuous,differentiablemappingoftheseparametersundersuitableconditions.Thechangerateoftheefficientportfolio'sweightswithrespecttovariationsaboutriskreturnestimationsisderivedbyestimatingtheLipschitzconstant.Ourgeneralquantitativeresultsshowthattheefficientportfolio''sweightsarenormallynotsosensitivetoestimationerrorsaboutmeansandvariances.Moreover,wepointoutthoseextremecaseswhichmightcausestabilityproblemsandhowtoavoidtheminpractice.Preliminarynumericalresultsarealsoprovidedasanillustrationtoourtheoreticalresults.

  • 标签: 估计误差 敏感性 均方差模型 有效证券组合 LIPSCHITZ连续
  • 简介:敏感的二种类型为静态地稳定的sailcrafts被建议。一种类型是关于质量的中心的位置的solar-radiation-pressure力量的敏感,并且另外的类型是关于态度的solar-radiation-pressure力量的敏感。敏感的二种类型代表solar-radiation-pressure力量怎么随着集体中心和态度的位置变化。有更大的敏感的Sailcrafts经历solar-radiation-pressure力量的更大的错误,导致更大的轨道错误,,由模拟示威了。然后作为案例研究,详细公式被导出与四张三角形的风帆为sailcrafts计算敏感。根据这些公式,敏感打字以便减少两个,在反对风帆之间的角度不应该太大,并且质量的中心应该远是离四张风帆并且尽可能的对称的轴尽可能靠近的离开sailcraft的压力的中心。

  • 标签: 敏感性分析 静态稳定 类型 辐射压力 重心位置 公式推导
  • 简介:在这篇文章,为作为直径地小的电磁的包括的远地的察觉的一个拓扑的敏感框架被建立。在固定频率的电的远地的散布振幅的单个、多重的大小的盒子被考虑。算法的性能为定位包括以它的分辨率和敏感理论上被分析。关于测量和中等噪音的框架的稳定性被讨论。而且,signal-to-noise比率的量的结果被介绍。一些数字结果被介绍与单个、多重的大小说明建议框架的察觉能力。

  • 标签: 检测能力 灵敏度 拓扑 电磁 夹杂 散射振幅
  • 简介:TheensemblebasedforecastsensitivitytoobservationmethodbyLiuandKalnayisappliedtotheSPEEDY-LETKFsystemtoestimatetheobservationimpactofthreetypesofsimulatedobservations.Theestimationresultsshowthatalltypesofobservationshavepositiveimpactonshort-rangeforecast.ThelargestimpactinNorthernHemisphereisproducedbyrawinsondes,followedbysatelliteretrievedprofilesandclouddriftwinddata,whichinSouthernHemisphereisproducedbysatelliteretrievedprofiles,rawinsondesandclouddriftwinddata.SatelliteretrievedprofilesinfluencemoreontheSouthernHemispherethanontheNorthernHemisphereduetofewobservationsfromrawinsondesintheSouthernHemisphere.Atthelevelof200to300hPa,thelargestimpactisattributedtowindobservationsfromrawinsondesandclouddriftwind.

  • 标签: observation impact EFSO LETKF
  • 简介:Thisletterreportstrafficflowsensitivitytovisco-elasticity,withthetrafficflowmodelingbrieflydescribedatfirstandthenusedtodotrafficflowsimulationswhoseresultscanreflectthepropertiesofspatial–temporalevolutionofringtrafficflow.Itrevealsthatvisco-elasticityplayscrucialroleinformationoftrafficflowpatterns,implyingthatself-organizationoftrafficflowiscrucialindeterminingtrafficflowstatus.

  • 标签: 交通流量 粘弹性 敏感性 交通流模拟 交通流模式 交通流状态
  • 简介:整体变换(et)方法被显示了在为适应观察推广提供指导有用。它在整体subspace用它的相应转变矩阵为各可能的推广预言预报错误变化减小。在这份报纸,一个新基于et的敏感(et)方法,以分析错误变化减小计算预报错误变化减小的坡度,被建议为可能的适应观察指定区域。et是ET的第一顺序近似;它要求就一个转变矩阵的一计算,增加计算效率(在计算费用的60%80%减小)。ETS坡度的明确的数学明确的表达被导出并且描述。ET和et方法为比较被用于飓风艾琳(2011)箱子和一个重降雨箱子。数字结果暗示ETS和et估计的敏感区域是类似的。然而,et是更有效的,特别地当分辨率更高,整体成员的数字更大时。

  • 标签: 适应性观测 矩阵集合 灵敏度 自适应 误差方差 计算效率
  • 简介:Hot-tearingcracksusuallyformnearthesolidustemperature.Itiscausedbyacombinationoftensilestressandmetallurgicalembrittlement.Inordertoquantifyembrittlementandtoincorporateitinthethermal-stressanalysis,manydifferentcriteriahavebeendeveloped.Amongthem,thesubmergedsplit-chilltensile(SSCT)testisanefficientone.ThispapertriestouseSSCTtoestimatethecriticalstrainofhottearingforsomesteels.

  • 标签: 拉伸试验 热撕裂 裂纹敏感性 热应力分析 临界应变 固相线
  • 简介:Thispaperisconcernedwiththeoptimumdesignandsensitivityanalysismethodsofpiezo-electricintelligenttrussesonthestructuralstiffnessandfree-vibrationfrequency.Onthebasisofthefiniteel-ementmethodandtakingintoaccountthemechanical-electriccouplingeffectunderelectricloadandme-chanicalload,thecomputationalformulaofsensitivitiesofstructuraldisplacementandfree-vibrationfrequen-cywithrespecttothesizeandshapedesignvariablesareproposed.Anewkindofdesignvariableoftheelectricvoltageandthecalculatingmethodofdisplacementsensitivitywithrespecttotheelectricvoltagevari-ableispresented.Thenewmethodforstructuraldeformationcontrolbyoptimizingthevoltagesofpiezoelec-tricactivebarsisgiven.ThenumericalmethodsofoptimumdesignandsensitivityanalysisforpiezoelectrictrussstructuresareimplementedinJIFEXsoftware.Numericalexamplesdemonstratetheeffectivenessofthemethodsandtheprogram.

  • 标签: PIEZOELECTRIC INTELLIGENT TRUSS mechanical-electric COUPLING STIFFNESS
  • 简介:Theshape-from-momentsproblemistoreconstructaplanarpolygonfromasetofitscomplexmoments.Toreconstructapolygonmeanstoestimatetheverticesandtheorderingofthevertices.Wenoticethatsomecoefficientsareveryimportantinfindingouttheorderingofthevertices.Weintroducesensitivefactorsforthecoefficientsanduseittoanalyzesensitivity.Thesefactorsarealsousefulforthesensitivityofthevertices.

  • 标签: 瞬间形状 平面多边形 灵敏度分析 常量系数
  • 简介:Anovelstructureoffiberopticbiosensoranditsprincipleareintroduced.Thesampleisdetectedinmicrochannelsofseveralmicronsdiameterinfiberopticbiosensors.Therelationbetweentheopticfibertaperedangleandthefluorescenceincidentangleiscalculatedinsignalreceivingpart.Asthesensorisazero-ordersystem,calculatingformulaofthestaticsensitivityisderived.WhenZnSenano-crystallineclusterisusedformarkingthemolecules,thestaticsensitivityforfiberopticbiosensorsiscalculated.Atthesametime,therelationbetweenthestaticsensitivityandtheratioofexcitingwavelengthtofluorescencewavelengthispresented.

  • 标签: 光学纤维 生物传感器 静态灵敏度 原理
  • 简介:光读出uncooled红外线的察觉者,与沥青尺寸60m采用一个没有底层的焦点的飞机数组,被建立。双性人层结构错配的压力导致的反射镜变丑被讨论,接着,决定光读出敏感和最佳的过滤器位置的一个通用答案被发现。由使用这个答案,为飞机反射镜能理论上作为与常规操作相比增加80%的理想的光读出敏感,和敏感损失也由反射镜变丑罐头引起了被归结为合理水平。

  • 标签: 灵敏度分析 光学读出 非致冷红外探测器 非制冷红外探测器 焦平面阵列 应力变形