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12 个结果
  • 简介:SolidModelingEror:AnalysisandCompensation①XuZhigangHuangKezhengAiXingShanLianyeColegeofMechanicalEngineering,ShandongUniversi...

  • 标签: SOLID ERROR ERROR FITTING ERROR compensation.
  • 简介:当它极大地影响用户满足的度,申请发射性能对系统站台开发者和供应商很重要。改进应用程序发射性能的最最有效的方法是用一个稳固的州的驱动器(SSD)代替一个硬盘驱动器(HDD),它最近变得买得起、流行。一个自然问题当时是是否用一个新SSD知道的优化器代替传统的HDD知道的申请发射台。我们由在SSD上分析HDD知道的申请发射台的无效然后建议预取计划的新SSD知道的应用探讨这个问题,叫了快申请跑步者(快)。关键想法快是重叠有SSD存取(I/O)的计算(中央处理器)时间时间在应用程序发射期间。快由一套用户级的部件和LinuxOS(操作系统)提供的系统调试工具组成。因此,没有核重新编译,能容易快在任何最近的Linux版本被部署。我们与运用Linux2.6.32OS的SSD在桌面PC上快实现并且由运行一套使用得广泛地的应用程序评估它,表明象与没有prefetcher的PC相比的申请发射时间的28%减小的一般水准。

  • 标签: 硬盘驱动器 应用程序 固态驱动器 启动性能 LINUX版本 FAST
  • 简介:AgingofasolidcompositepropellantcontainingHTPB/AP/ALwasperformedinordertovalidatetheconformanceoftheacceleratedagingdatatotheArrheniuslaw.Themainobjectiveoftheworkwastoexaminetheinfluenceoftheaziridinebondingagentsfamilyonthepropellantaging.Agingofthepreparedpropellantsampleswasconductedasfollows:1.Foursamples,onefreeofbondingagents,andthreecontainingaziridinebasedbondingagentsMAPO,HX-752,MAT4wereagedat65°C.2.AnotherfoursamplesbasedonHX-752,MAT4withdifferentcuringagentswereagedat65°C.Themeasuredmechanicalpropertiesofthefreebondingagentpropellantsampleswereveryfarfromthespecificationsandthisillustratestheimportanceofthebondingagentsinboththepreparationandtheagingphases.Thepreparedbondingagent"MAT4"gaveremarkableimprovementsofthemechanicalpropertiescomparingwithHX-752andMAPO.Theaziridinebondingagentsfamilyinhibitedtherateofdecompositionofthepropellantduringtheagingperiodsandsupportedthepropellantmatrixagainstdecompositionattheelevatetemperatures.UsingofHMDIascuringagentgaveslightbettermechanicalpropertiestotheIPDI.

  • 标签: AGING solid propellant bonding AGENTS curing
  • 简介:Theballisticpropertiesofalowsolidloadingcompositesolidpropellantfamily(Butalites)wasstudiedexperimentallybyusingpropellantformulationsbasedonhydroxy-terminatedpolybutadienepre-polymer(HTPB)asfuelbindermainbackbone,monoandbi-modalsystemammoniumperchlorateoxidizer(AP),copperchromite(CC)asburningrateacceleratorandaluminumpowder(Al)asmetallicfuel.HigherpressuresandAPcontentsaswellassmallerAPparticlesizewerefoundtoincreaseburningrate.ThesamebehaviorverifiedwithAlandCCaddition.AsignificantincreaseofburningratewasrecordedwhenCCaddedtothealuminizedformulationscomparedwiththenon-aluminizedofthesameoxidizersolidloadingandparticlesize.

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  • 简介:Thecombustion(ballistic)propertiesofahighsolidloadingcompositesolidpropellantfamily(Butalites)wasstudiedexperimentallybyusingpropellantformulationsbasedonhydroxy-terminatedpolybutadienepre-polymer(HTPB)asafuelbindermainbackbone,bi-modalsystemammoniumperchlorateoxidizer(AP)andaluminumpowder(Al)asmetallicfuel.Burningratesweredoubledatvariouspressures,whensolidsloading(APand17%Al)wereincreasedfrom80to88%andthemeasuredcharacteristicvelocityvalueswereincreasedbyabout100m/sec.Thepressureexponent(n)valueswerelowerwith80-85%solidsloading.Theburningrateswereincreasedbyabout2-5%whencomparingthedataobtainedbystaticfiringwiththoseobtainedbythestrandburnermethod.

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  • 简介:Atime-resolvednumericalcomputationalapproach,involvingthecombustionofdouble-basepropellantisperformedonthermalprotectionmaterialforSRMnozzle.AnimplicitNavier-StokesSolverisselectedtosimulatetwo-dimensionalaxial-symmetricunsteadyturbulentflowofcompressiblefluid.ThegoverningequationsarediscreditedbyusingthefiniteVolumemethod.S-Aturbulencemodelisemployed.CFDschemeisimplementedtoinvestigatethetemperaturedistributioncausesatnozzlethroatinsertscompositematerial.DifferentparametershavebeenselectedfortheanalysistovalidatethetemperaturevariationinthethroatinsertsandbakingmaterialofSRMnozzle.TheadvancedSRMnozzlecompositematerialisalsocharacterizedforthehighthermostabilityandhighthermomechanicalcapabilitiestomakeitmorereliable,simplerandlighter.

  • 标签: 固体火箭发动机 刀片材料 喷嘴 热调 数值计算方法 STOKES
  • 简介:A3D-viewishelpfultoinstantlygraspwhatispresentedinadrawing.Thereexistavarietyofwaystopresentthesamepartwith3D-views.Tofacilitatethechoiceofanoptimumoneamongthem,theworkdividescompositesolidmodelsintothreecategories,soastoconveytheoriginalityofdesignconciselyandaccuratelybyusingtheleast'engineeringlanguage'.

  • 标签: 三维视图 固体模型 复合 配备 演示 优化
  • 简介:在这份报纸,有变化时间的内部液体的一个灵活海洋的起床人的颤动减小被使用边界控制方法和Lyapunovs直接方法学习。完成更精确、实际的起床人动态行为,有变化时间的内部液体的海洋的起床人的模型被一个分布式的参数系统(DPS)与部分微分方程(PDE)和包含空间和时间的函数的平常的微分方程(颂诗)建模。如果变化时间的内部液体被考虑,起床人的动态回答是完全不同的。边界控制基于PDE建模的原来的无限的维数和Lyapunovs直接方法在起床人的最高的边界被设计减少起床人颤动。一致固定和靠近环的稳定性基于建议边界控制被证明。模拟结果验证建议边界控制的有效性。

  • 标签: 边界控制 内部流体 海洋立管 动力学建模 柔性 李雅普诺夫直接方法
  • 简介:Thispaperaddressestheimportantintelligentpredictingproblemofperitonealabsorptionrateintheperitonealdialysistreamentprocessofrenalfailure.Astheindexofdialysisadequacy,KT/VandCcrarewidelyusedandaccepted.However,growingevidencesuggeststhatthefluidbalancemayplayacriticalroleindialysisadequacyandpatientoutcome.Peritonealfluidabsorptiondecreasestheperitonealfluidremoval.Understandingtheperitonealfluidabsorptionratewillhelpclinicianstoopthnizethedialysisdwelltime.Theneuralnetworkapproachisappliedtothepredictionofperitonealabsorptionrate.Comparedwithmultivariableregressionmethod,theexperimentalresultsshowedthatneuralnetworkmethodhasanadvantageovermultivariableregression.Theapplicationofthispredictingmethodbased-onneuralnetworkinclinicisinstructive.

  • 标签: 膜分离 神经网络 智力预测 膜吸收 自动控制
  • 简介:Wepresentthesolidmodeleditdistance(SMED),apowerfulandflexibleparadigmforexploitingshapesimilaritiesamongstCADmodels.ItisdesignedtomeasurethemagnitudeofdistortionsbetweentwoCADmodelsinboundaryrepresentation(B-rep).Wegivetheformaldefinitionbyanalogywithgrapheditdistance,oneofthemostpopulargraphmatchingmethods.Toavoidtheexpensivecomputationalcostpotentiallycausedbyexactcomputation,anapproximateprocedurebasedonthealignmentoflocalstructuresetsisprovidedinaddition.Inordertoverifytheflexibility,wemakeintensiveinvestigationsonthreetypicalapplicationsinmanufacturingindustry,anddescribehowourmethodcanbeadaptedtomeetthevariousrequirements.Furthermore,amultilevelmethodisproposedtomakefurtherimprovementsofthepresentedalgorithmonbotheffectivenessandefficiency,inwhichthemodelsarehierarchicallysegmentedintotheconfigurationsoffeatures.ExperimentresultsshowthatSMEDservesasareasonablemeasurementofshapesimilarityforCADmodels,andtheproposedapproachprovidesremarkableperformanceonareal-worldCADmodeldatabase.

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  • 简介:Shingledmagneticrecording(SMR)caneffectivelyincreasethecapacityofharddiskdrives(HDDs).HostawareSMR(HA-SMR)isexpectedtobemorepopularthanotherSMRmodelsbecauseofitsbackwardcompatibilityandnewSMR-specificAPIs.However,anHA-SMRdriveoftensuffersperformancedegradationunderwrite-intensiveworkloadsbecauseoffrequentnon-sequentialwritesbufferedinthediskcache.Thenon-sequentialwritesmainlycomefromupdatewrites,smallrandomwritesandout-of-orderwrites.Inthispaper,weproposeahybridstoragesystemcalledROCOwhichaimstouseasolidstatedrive(SSD)cachetoimprovetheperformanceofanHA-SMRdrive.ROCOreordersout-of-orderwritesbelongingtothesamezoneandusestheSSDcachetoabsorbupdatewritesandsmallrandomwrites.WealsodesignadatareplacementalgorithmcalledCREAfortheSSDcache.CREAfirstconductszone-orientedhot/colddataidentificationtoidentifycold-cachedzonesandhot-cachedzones,andthenevictsdatablocksbelongingtocolderzoneswithhigherprioritiesthatcanbesequentiallywrittenorwrittenthroughhost-sideread-modify-writeoperations.Itgivesthelowestprioritytodatablocksbelongingtothehottest-cachedzonethathavetobenon-sequentiallywritten.ExperimentalresultsshowthatROCOcaneffectivelyreducenon-sequentialwritestotheHA-SMRdriveandimprovetheperformanceoftheHA-SMRdrive.

  • 标签: solid state reordering zone-oriented DRIVE (SSD)cache