学科分类
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74 个结果
  • 简介:Accesscontrolinmulti-domainenvironmentsisoneoftheimportantquestionsofbuildingcoalitionbetweendomains.OnthebasisofRBACaccesscontrolmodel,theconceptsofroledelegationandrolemappingareproposed,whichsupportthethird-partyauthorization.Then,adistributedRBACmodelispresented.Finallytheimplementationissuesarediscussed.

  • 标签: 运算控制 RBAC模型 图论 计算机安全 区域环境
  • 简介:调查控制网络优化设计与标准有关,例如精确,可靠性,敏感和费用,并且这些标准与对方仔细相关。为调查控制网络模拟优化设计的一个新方法被建议。这个方法基于观察价值的内部可靠性索引。为调查控制网络优化图案,分析方法和模拟方法有二个方法,并且两个都随广阔计算取决于计算程序。

  • 标签: 测量控制网 优化设计 可靠性准则法 冗余观测重量
  • 简介:传统的控制策略有困难在地震刺激下面处理结构,时间变量特征和构造控制系统的参数不确定性的非线性的行为。与模糊控制相结合的off-and-towards-equilibrium(OTE)策略在这篇论文被介绍克服这些困难。根据OTE策略,控制力量从在结构,令人激动的力量和控制力量的运动之间的一种机械关系的观点被设计。OTE策略的优点是它能被用于许多控制系统。以便评估建议策略的表演,地震表演一三故事砍用一个模糊逻辑控制器(FLC)与一个活跃的腱系统(ATS)造被学习。模糊控制器的主要优点是它处理结构的任何非线性的行为的固有的坚韧性和能力。然而,没有设计指南为FLC建立相应检核尺桌子。为FLC基于建议策略,在学习下面与大楼联系的一张检核尺桌子被开发,它然后允许一个详细算法的形成。在这研究获得的结果证明建议策略比线性二次的管理者(LQR)稍微好表现策略,当在LQR控制器上拥有几个优点时。因而,建议策略的可行性和有效性被验证。

  • 标签: 建筑结构 振动控制策略 离复位控制算法 模糊控制 地震激励
  • 简介:Inthispaper,awavelet-filteredgenetic-neuro-fuzzy(WGNF)controlsystemdesignframeworkforresponsecontrolofahighwaybridgeundervariousearthquakeloadsisdiscussed.TheWGNFcontrollerisdevelopedbycombiningfuzzylogic,discretewavelettransform,geneticalgorithms,andneuralnetworksforuseasacontrolalgorithm.ToevaluatetheperformanceoftheWGNFalgorithm,itistestedonahighwaybridgeequippedwithhydraulicactuators.Itcontrolstheactuatorsinstalledontheabutmentsofthehighwaybridgestructure.Variousearthquakesusedasinputsignalsincludeanartificialearthquake,theEl-Centro,Kobe,NorthPalmSprings,TurkeyBolu,Chi-Chi,andNorthridgeearthquakes.ItisprovedthattheWGNFcontrolsystemiseffectiveinmitigatingthevibrationofthehighwaybridgeunderavarietyofseismicexcitation.

  • 标签: structural control WAVELET TRANSFORM GENETIC ALGOR
  • 简介:Ahybridcontrolplatformisinvestigatedinthispapertomitigatemicrovibrationstoagroupofvibrationsensitiveequipmentinstalledinamicroelectronicsfacilitysubjecttonearbyroadvehicle-inducedhorizontalandverticalgroundmotions.Thehybridcontrolplatform,onwhichmicroelectronicsequipmentisinstalled,ismountedonabuildingfloorthroughaseriesofpassivemountsandcontrolledbyhydraulicactuatorsinbothhorizontalandverticaldirections.Thecontrolplatformisanelasticbodywithsignificantbendingmodesofvibration,andasub-optimalcontrolalgorithmisusedtomanipulatethehydraulicactuatorswithactuatordynamicsincluded.Thefiniteelementmodelandtheequationsofmotionofthecoupledplatform-buildingsystemarethenestablishedintheabsolutecoordinatetofacilitatethefeedbackcontrolandperformanceevaluationoftheplatform.Thehorizontalandverticalgroundvibrationsatthebaseofthebuildinginducedbynearbymovingroadvehiclesareassumedtobestationaryrandomprocesses.Atypicalthree-storymicroelectronicsbuildingisselectedasacasestudy.Thecasestudyshowsthattheverticalvibrationofthemicroelectronicsbuildingishigherthanthehorizontal.TheuseofahybridcontrolplatformcaneffectivelyreducebothhorizontalandverticalmicrovibrationsofthemicroelectronicsequipmenttothelevelwhichsatisfiesthestringentmicroscalevelocityrequirementspecifiedintheBoltBeranek&Newman(BBN)criteria.

  • 标签: 微小振动 道路交通 微电子工程 有限元分析
  • 简介:Underwatervehicleplaysanimportantroleinoceanengineering.Depthcontrolbyfinisoneofthedifficultiesforunderwatervehicleinmotioncontrol.Depthcontrolisindirectduetothefreedomcouplingbetweentrimandaxialmotion.Itincludesthemethodofdynamicanalysisandlift-resistance-coefficientexperimentandtheoryalgorithm.Byconsideringthecurrentspeedanddepthdeviation,comprehensiveinterpretationisusedinobject-planninginstruction.Expecteddepthistransformedintoexpectedtrim.Dynamicoutputfluctuationcanbeavoided,whichiscausedbylinearmappingofdeviation.Itissteadyandaccurateforthemotionofcontrolledunderwatervehicles.Thefeasibilityandefficiencyofthecontrolmethodaretestifiedinthepoolandnaturalareaforexperiments.

  • 标签: 水下机器人 运动控制 线性映射 修剪 散热片 海洋工程
  • 简介:在这份报纸,一个最佳的H鈭?控制算法被用于在一座有多层楼的大楼的第一个故事安装由于地震刺激减少它的interstory飘移的一个活跃的腱系统的设计。完成最佳的控制性能并且保证控制系统的稳定性,选择控制参数纬和伪的最佳策略被开发。分析表情上面并且纬和伪的更低的界限与州的反馈控制为一个单个degree-of-freedom系统被获得。为纬和伪的选择范围图形地被定义以便控制系统总是是稳定的,控制性能比由常规LQR控制算法好。来自在真实地震刺激下面的一座控制三故事的大楼的数字结果证明山峰第一interstory飘移能显著地在10%造的重量附近与最大的控制力量被减少。一份最佳设计流动图表被提供。为推迟时间的结构,另外,这研究给了明确的公式计算纬和伪的批评价值。系统稳定性和控制性能能因此甚至与时间延期被保证。

  • 标签: H∞控制 时间延迟 抗震结构 状态反馈控制系统 漂移 控制算法
  • 简介:Inthispaper,anewhybridcontroltechnique,basedonacombinationofbase-isolationandsemi-activevariablestiffness/dampinginasuperstructure,ispresented.Toillustratetheefficiencyoftheproposedcontrolsystem,modeltestsonamini-electromagneticshakingtableandanumericalsimulationwereperformed.Thetestandnumericalcalculationresultsindicatethatthisnewhybridcontrolmodewithadditionaldampingandsmalleradditionalstiffnesscanachieveabettercontrolefficiency.

  • 标签: 地震 混合控制 数值模拟 阻尼控制 刚度控制
  • 简介:Anewapproachtoreducingtheseismicresponseofspatialstructureswithmagneto-rheological(MR)dampersispresentedinthispaper.TheGeneticAlgorithmwithsmallpopulations(μGA)isusedtooptimizethecontrolfortheMRdamperstoreducestructuralvibration,whichisdifficulttoachieveusingclassicaloptimalcontrol.TheadvantagesofμGAaretheuseofglobalpropertiesandthatfewerconditionsarerequiredtoobtaintheoptimalfunction.Numericalresultsdemonstratetheeffectivenessoftheproposedmethodinreducingtheseismicresponseofstructures.

  • 标签: 偏轴结构 半主动控制 磁流变学 MR 阻尼器 遗传算法
  • 简介:Inthisstudy,theentiremitochondrialDNA(mtDNA)controlregion(CR)ofPholisfangiwasamplifiedviapolymerasechainreactionfollowedbydirectsequencing.ThelengthofthemtDNACRconsensussequenceofP.fangiwas853bpinlength.Inaccordancewiththerecognitionsitesaswerepreviouslyreportedinfishspecies,themtDNACRsequenceofP.fangicanbedividedinto3domains,i.e.,theextendedterminalassociatedsequence(ETAS),thecentralconservedsequenceblock(CSB),andtheCSBdomain.Inaddition,thefollowingstructureswereidentifiedinthemtDNACRsequenceofP.fangi:2ETASsintheETASdomain(TASandcTAS),6CSBsinthecentralCSBdomain(CSB-FtoCSB-A),and3CSBsintheCSBdomain(CSB-1toCSB-3).ThesedemonstratedthatthestructureofthemtDNACRofP.fangiwassubstantiallydifferentfromthoseofmostotherfishspecies.ThemtDNACRsequenceofP.fangicontainedoneconservedregionfrom656bpto815bp.Similartomostotherfishspecies,P.fangihasnotandemrepeatsequencesinitsmtDNACRsequence.PhylogeneticanalysisbasedonthecompletemtDNACRsequencesshowedthattherewerenogeneticdifferenceswithinP.fangipopulationsofthesamegeographicaloriginandbetweenP.fangipopulationsofdifferentgeographicalorigins.

  • 标签: 线粒体DNA控制区 结构 系统学 DNA序列 MTDNA 聚合酶链反应
  • 简介:AnobviousmotivationofthispaperistoexaminetheeffectivenessofthelateralvibrationcontrolofajackettypeoffshoreplatformwithanAMDcontroldevice,inconjunctionwithH2controlalgorithm,whichisanoptimalfrequen.cydomaincontrolmethodbasedonminimizationofH2normofthesystemtransferfunction.Inthisstudy,theoffshoreplatformismodelednumericallybyuseofthefiniteelementmethod,insteadofalumpedmassmodel.Thisstructuralmodelislatersimplifiedtobesingle-degree-of-freedom(SDOF)systembyextractingthefirstvibrationmodeofthestruc.ture.Thecorresponding″generalized″waveforceisdeterminedbasedonananalyticalapproximationofthefirstmodeshapefunction,thephysicalwaveloadingbeingcalculatedfromthelinearizedMorisonequation.Thisapproachfacilitatesthefilterdesignforthegeneralizedforce.Furthermore,thepresentpaperalsointendstomakenumericalcompari.sonbetweenH2activecontrolandthecorrespondingpassivecontrolusingaTMDwiththesamedeviceparameters.

  • 标签: ACTIVE control of fshore PLATFORM VIBRATION
  • 简介:ThereareplentyofSinianandCambrianpotentialshalegasresourcesinSouthChina,whichischaracterizedbyhighthermalevolutiondegrees,poordrillingperformancesandonlyoccursinlocalareas.Takingtheprinciple“hightofindlow”isthekeyissuetoachievingabreakthroughinoldershale.ChinaGeologicalSurveydrilledintheperipheryoftheProterozoicbasement,i.e.theHuanglinganticline,inthewesternHubei,andHannanpaleocontinentinthesouthernShanxi.Itreceivedhigh-qualitygas-bearingshalewithrelativelylowRointheinLowerCambrianNiutitangformationandSinianDoushantuoformation.BasedongeologicalconditionsofshalegasreservoirsintheHuanglinganticline,thispaperputsforwardthenewmodelnamed“Controloverreservoirsbyperipheryofbasement”aboutshalegasaccumulation,suggestingthattheshaledepositedinadeepwatercontinentalshelfintheperipheryofthebasementischaracterizedbyshallowburial,ashortburialtime,stabletectonics,relativelylowthermalevolutiondegrees,andshalegasreservoirsinagoodcondition.TheshaleoftheSinian-CambrianstratadepositedindeepwatercontinentalshelvesintheperipheryofChuanzhongpaleo-upliftinSichuan,HannanpaleocontinentinthesouthernShanxi,HuanglinganticlineinwesternHubeiandJiangnang-Xuefengpaleo-upliftinHunanandGuizhouprovincehavegoodshalegasexplorationpotential.

  • 标签: Huangling UPLIFT EVOLUTION SHALE gas CONTROL
  • 简介:ThereisalownutrientlevelintheAoshanBay.InJune1999,thechemicaladjustmentandcontrolexperimentwasmadeintheAoshanBay.Followingtractsinvestigationwascarriedoutbeforetheexperimentandonthe1st,2nd,4th,5th,6thand45thday/aftertheexperiment.Whilethevarianceofamountofphytoplankton,thereplacementofsuperiorspeciesandthespeciescompositionofphytoplanktonwereresearched.TheresultsshowthattheamountofphytoplanktonintheAoshanBayrisesgraduallyaftertheexperiment.CeratiummacrocerosCleveofpyrophytawasthedominantspeciesbeforetheexperiment,itsdominantindexwas37.7%.Sixdaysaftertheexperiment,itsdominantindexdroppedto17.6%.MeanwhilethedominantindexofAsterionellajaponicsCleverosefrom7.1%to39.2%,itbecamethefirstdominantspecies.Forty-fivedaysaftertheexperiment,theamountofphytoplanktonintheAoshanBaywas5.15to137.32timesmorethanthatin1997.

  • 标签: CHEMICAL adjustment and control the Aoshan
  • 简介:ByimplementingtheARGOprogram,alargenumberofT-Sprofilescanbeobservedintheworldocean.However,itisverydifficulttoexaminechangesofthesensitivityofthesensorsequippedattheARGOfloats,becauseitisdifficulttounderstandtheirconditionintheseaandthereliabilityofthedata.Qualitycontrolmustbedoneinordertoavoidthewrongconclusiondeducedfromthewrongdata.OneoftherealisticmethodsforqualitycontroloftheARGOdataisthecomparisonwiththelocalclimatology.HighqualityclimatologicalT-SmodelsinnorthwestPacifichavebeenbuiltbasedontheNansenbottledataandCTDdataforthequalitycontrolinNMDIS.ThemodelsareusedtochecktheARGOdatainthisareaandhavegotgoodresult.

  • 标签: 质量控制 传感器 可靠性 气候学 太平洋 模拟
  • 简介:Thepurposeofthisstudyistoinvestigatetheeffectivenessofmulti-tunedmassdampers(MTMD)onmitigatingvi-brationofanoffshoreoilplatformsubjectedtooceanwaveloading.Anoptimaldesignmethodisusedtodeterminetheop-timaldamperparametersunderoceanwaveloading.TheforceonthestructureisdeterminedbyuseofthelinearizedMorisonequation.InvestigationonthedeckmotionwithandwithoutMTMDonthestructureismadeunderdesigncondi-tions.TheresultsshowthatMTMDwiththeoptimizedparameterssuppresstheresponseofeachstructuralmode.ThesensitivityofoptimumvaluesofMTMDtocharacteristicwaveparametersisalsoanalyzed.ItisindicatedthatasingleTMDonthedeckofaplatformcanhavethebestperformance,andthesmallthedampingvalueofTMD,thebetterthevibrationcontrol.

  • 标签: OFFSHORE structure multi-tuned MASS DAMPER STRUCTURAL
  • 简介:摘要:在北Qaidam盆的侏罗记煤措施的分发被地区性的结构显然控制。基于煤田探索的存在数据并且与煤田地下室结构,主要差错的特征,和煤措施的分发的分析结合了,这份报纸向前在北Qaidam盆带给煤田的一个计划构造师的单位和控制煤的结构的式样的定义。煤措施的分发的结构控制进一步被讨论。煤的分发从东方从北方测量进带状配列的特征到南方和块到西方的后来,Indosinian导致了的地区性的构造活动的几个阶段。结果显示结构的变丑在三的前面是最强烈的高举系上带子,它被戳的联合描绘。煤措施被高举到浅形成,并且对容易被利用,但是因为严重损坏,矿的规模是小的。相反,压力和紧张在三消沉是弱的,与主要是的控制煤的结构的式样戳褶层和戳单斜层联合。在消沉的煤的分发是相对稳定的。消沉的更浅的部分将在北Qaidam盆为煤资源的探索和开发成为关键区域。

  • 标签: 煤矿 地区分布 地质构造 中国
  • 简介:Astheexplorationandexploitationofoilandgasproliferatethroughoutdeepwaterarea,therequirementsonthereliabilityofdynamicpositioningsystembecomeincreasinglystringent.Thecontrolobjectiveensuringsafetyoperationatdeepwaterwillnotbemetbyasinglecontrollerfordynamicpositioning.Inordertoincreasetheavailabilityandreliabilityofdynamicpositioningcontrolsystem,thetripleredundancyhardwareandsoftwarecontrolarchitecturesweredesignedanddevelopedaccordingtothesafespecificationsofDP-3classificationnotationfordynamicallypositionedshipsandrigs.Thehardwareredundantconfigurationtakestheformoftriple-redundanthotstandbyconfigurationincludingthreeidenticaloperatorstationsandthreereal-timecontrolcomputerswhichconnecteachotherthroughdualnetworks.Thefunctionofmotioncontrolandredundancymanagementofcontrolcomputerswereimplementedbysoftwareonthereal-timeoperatingsystemVxWorks.Thesoftwarerealizationoftaskloosesynchronization,majorityvotingandfaultdetectionwerepresentedindetails.Ahierarchicalsoftwarearchitecturewasplanedduringthedevelopmentofsoftware,consistingofapplicationlayer,real-timelayerandphysicallayer.ThebehavioroftheDP-3dynamicpositioningcontrolsystemwasmodeledbyaMarkovmodeltoanalyzeitsreliability.Theeffectsofvariationinparametersonthereliabilitymeasureswereinvestigated.Thetimedomaindynamicsimulationwascarriedoutonadeepwaterdrillingrigtoprovethefeasibilityoftheproposedcontrolarchitecture.

  • 标签: 动力定位系统 可靠性分析 控制体系 DP 设计 实时操作系统