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113 个结果
  • 简介:TherobustH∞controlfornetworkedcontrolsystemswithbothstochasticnetwork-induceddelayanddatapacketdropoutisstudied.Whendataaretransmittedovernetwork,thestochasticdatapacketdropoutprocesscanbedescribedbyatwo-stateMarkovchain.Thenetworkedcontrolsystemswithstochasticnetwork-induceddelayanddatapacketdropoutaremodeledasadiscretetimeMarkovjumplinearsystemwithtwooperationmodes.ThesuffcientconditionofrobustH∞controlfornetworkedcontrolsystemsstabilizedbystatefeedbackcontrollerispresentedintermsoflinearmatrixinequality.Thestatefeedbackcontrollercanbeconstructedviathesolutionofasetoflinearmatrixinequalities.Anexampleisgiventoverifytheeffectivenessofthemethodproposed.

  • 标签: 网络控制系统 H∞控制 线性系统 神经网络
  • 简介:Akindofnetworkedcontrolsystemisstudied;thenetworkedcontrolsystemwithnoisedisturbanceismodeledbasedoninformationschedulingandcontrolco-design.Augmentedstatematrixanalysismethodisintroduced,androbustfault-tolerantcontrolproblemofnetworkedcontrolsystemswithnoisedisturbanceunderactuatorfailuresisstudied.Theparametricexpressionofthecontrollerunderactuatorfailuresisgiven.Furthermore,theresultisanalyzedbysimulationtests,whichnotonlysatisfiesthenetworkedcontrolsystemsstability,butalsodecreasesthedatainformationnumberinnetworkchannelandmakesfulluseofthenetworkresources.

  • 标签: 神经网络控制 信息调度 线性矩阵不等式 系统分析
  • 简介:Inthispaper,aphotoelectricdeviceisintroduced,whichisusedinde-tectingthequalityoninternalsurfaceofthinandlongsteelpipe.Inthisdevice,theCCTVlensisusedforextracttheflawinformationoninternalsurfaceofthepipe,andmakeIBM-PC/AT486computerascontrollingandimageprocessingsystem.Bythisinstrument,thefunctions,suchasthedigitalconversiongofinputinformation,imageprocessing,classificationofrecognitionandoutputdisplaycanbeobtained,Inthepetroleumandchemicalindustry,byusingthisapparatus,wecandetectthequalithoninternalsurfaceofvariousmetalpipeswithreal-timeautomatically.

  • 标签: 探伤检验 图像处理 质量控制 钢管内表面 光电探测
  • 简介:ThispaperdescribesafullchannelTVmodulatorforallTVsystems,whichhasbeendevelopedsuccessfully.ItemploysadvancedtechniquesuchasPLLfrequencysynthesizerwithmicrowaveintegratedcircuit,andwidebandmicrostripVCOanddigital-analogcombinedintegratedcircuits.Thekeytechniqueofthemodulatorissettledsuccessfully.AllthespecificationsofthemodulatoragreewithTechnicalStandardofChina,whicharetestedbytheauthorityofChina.

  • 标签: TV MODULATOR PLL FREQUENCY SYNTHESIZER Full
  • 简介:ThepurecubicGaN(c-GaN)hasbeengrownon(001)GaAssubstratesbyECR-PAMOCVDtechniqueatlowtemperatureusingTMGaandhighpureN2asGaandNsources,respectively.TheeffectsofsubstratepretreatmentconditionsonqualityofcubicGaNepilayerareinvestigatedbythemeasurementsofTEMandXRD.Itisfoundthathydrogenplasmacleaning,nitridationandbufferlayergrowthareveryimportantforqualityofcubicGaNepilayer.

  • 标签: 氮化镓 立方体 氢等离子体 渗氮 缓冲层
  • 简介:InordertoevaluatetheimagingqualityofCCDcamerasfullyandrapidly,theminimumresolvablecontrast(MRC)ispresentedinthispaperandthesystemofmeasuringMRCisconstructedaswell,inwhichtwointegratingspheresareproposedtoilluminatetwosidesofthetargetrespectively.Thevariablecontrastcanbeobtainedbyregulatingtheluminanceofintegratingspheres.Experimentalresultsindicatethattheerrorofmeasuringluminanceiswithin±0.3cd/m2,MRCriseswiththeincreaseofthespatialfrequency.TheexperimentalresultsshowthatthemethodproposedisaneffectiveapproachtoevaluatetheimagingqualityofCCDcameras.

  • 标签: CCD 照相机 图象处理 图象评估 亮度
  • 简介:Theimpactanglecontroloverguidance(IACG)lawagainststationarytargetsisproposedbyusingfeedbacklinearizationcontrol(FLC)andfinitetimecontrol(FTC).First,thispapertransformsthekinematicsequationofguidancesystemsintothefeedbackablelinearizationmodel,inwhichtheguidancelawisobtainedwithoutconsideringtheimpactangleviaFLC.Forthepurposeofthelineofsight(LOS)angleanditsrateconvergingtothedesiredvalues,thesecond-orderLOSangleisconsideredasadouble-integralsystem.Then,thispaperutilizesFTCtodesignacontrollerwhichcanguaranteethestatesofthedouble-integralsystemconvergingtothedesiredvalues.NumericalsimulationillustratestheperformanceoftheIACG,incontrasttotheexistingguidancelaw.

  • 标签: guidance LAW impact ANGLE FEEDBACK LINEARIZATION
  • 简介:Objectivevideoqualityassessmentmethodsoftenevaluatealltheframesregardlessoftheirimportance.Forwirelessdistortedvideos,noteveryframehasthesamecontributiontothefinaloverallqualityduetothechannelfadingandinterference,whichmayleadtothecapacityvariationintemporal.Besides,withthecontentsimilarityanderrorpropagationpatternintemporaldomain,itispossibletoevaluatetheoverallqualitywithonlypartoftheframes.Inthispaper,ademonstrationisperformedtoshowthatthevideoqualitycanbeevaluatedwithreducedframesset(RFS),andastatetransitionmodelisproposedtoextracttheRFS.Atlast,avideoqualityassessment(VQA)methodiscarriedoutbasedonRFS.Comparedwithseveralstate-of-the-artmethods,ourmethodcanachieveasuitableaccuracywithlessframestobeprocessed.

  • 标签: VQA wireless distortion quality of experience
  • 简介:MostofImageQualityAssessment(IQA)metricsconsistoftwoprocesses.Inthefirstprocess,qualitymapofimageismeasuredlocally.Inthesecondprocess,thelastqualityscoreisconvertedfromthequalitymapbyusingthepoolingstrategy.Thefirstprocesshadbeenmadeeffectiveandsignificantprogresses,whilethesecondprocesswasalwaysdoneinsimpleways.Inthesecondprocessofthepoolingstrategy,theoptimalperceptualpoolingweightsshouldbedeterminedandcomputedaccordingtoHumanVisualSystem(HVS).Thus,areliablespatialpoolingmathematicalmodelbasedonHVSisanimportantissueworthyofstudy.Inthispaper,anewVisualPerceptualPoolingStrategy(VPPS)forIQAispresentedbasedoncontrastsensitivityandluminancesensitivityofHVS.ExperimentalresultswiththeLIVEdatabaseshowthatthevisualperceptualweights,obtainedbytheproposedpoolingstrategy,caneffectivelyandsignificantlyimprovetheperformancesoftheIQAmetricswithMeanStructuralSIMilarity(MSSIM)orPhaseQuantizationCode(PQC).ItisconfirmedthattheproposedVPPSdemonstratespromisingresultsforimprovingtheperformancesofexistingIQAmetrics.

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  • 简介:ThisletteranalyzesthereasonswhytheknownNeuralBackPromulgation(NBP)networklearningalgorithmhasslowerspeedandgreatersampleerror.Basedontheanalysisandexperiment,thetraininggroupdescendingEnhancedCombinationAlgorithm(ECA)isproposed.TheanalysisofthegeneralizedpropertyandsampleerrorshowsthattheECAcanheightenthestudyspeedandreduceindividualerror.

  • 标签: 学习算法 神经反向传播网络 NBP 混合增强算法 ECA
  • 简介:Oneofthemaindriversforintelligenttransportationsystemsissafety.Adaptivecruisecontrol,asacommonsolutionfortrafficsafety,hasextendedfromradarstocameras.Duetohighmobilityofvehiclesandunevennessofroads,thepicturequalityofcamerashasbeengreatchallengesforcamera-basedadaptivecruisecontrol.Inthispaper,animagedistortioncorrectionalgorithmisaddressed.Ourmethodisbasedonopticalflowtechnologywhichisnormallyappliedinmotionestimationandvideocompressionresearch.Wearethefirsttoattempttoadaptitinimagedistortioncorrection.Twoopticalflowapproaches,theLucas-KanademethodandtheHorn-Schunckmethod,areselectedandcompared.Theprocedureofimagedistortioncorrectionusingtheopticalflowmethodhasbeentestedbybothsynthetictestimagesandcameraimages.TheexperimentalresultsshowthattheLucas-Kanademethodismoresuitableinthecorrectionofimagedistortion.

  • 标签: 自适应巡航控制系统 图像失真 校正算法 智能交通系统 畸变校正 安全问题
  • 简介:Inordertoformanemergencycontrolpolicytablequickly,thispaperproposesafastalgorithmofemergencycontrolnamed'micro-stepdiscretemethod',whichisbasedonthephysicalmeaningofthegradientandthediscretecharacteristicsofemergencycontrol.Thenitisimprovedthroughthestabilitycriterion,integralstep,andmicro-stepfactor.Thispapertakesgenerator-sheddingastheemergencycontrolmeasures.Astheoptimalgenerator-sheddingcontrolisessentiallyanoptimalcontrolproblemandthegenerator-sheddingvariablesarealwaysconstant,itisconvenienttousethecontrolparameteralgorithmtosolvetheproblem,whichcancalculatethegradientofthetransientstabilityfunctiontocontrolvariables.

  • 标签: 控制算法 紧急控制措施 最优控制问题 控制策略表 稳定性判据 发电机
  • 简介:存取控制计划被建议让系统宽信息管理(游泳)在实际应用程序处理属性撤回的问题。把基于的加密(ABE)基于属性,这个计划介绍代理重新加密机制和关键加密钥匙(KEK)树与属性撤回认识到有细密纹理的存取控制。这份报纸根据民用的航空的现状定义属性。与以前建议的一些另外的计划相比,这个计划不仅弄短密文(CT)和私人钥匙的长度而且改进加密和解密的效率。计划能抵抗串通攻击并且在游泳保证数据的安全。

  • 标签: 游泳 存取控制 代理重新加密 属性撤回
  • 简介:AdmissioncontrolplaysanimportantroleinprovidingQoStonetworkusers.Motivatedbythemeasurement-basedadmissioncontrolalgorithm,thisletterproposedanewadmissioncontrolapproachforintegratedservicepacketnetworkbasedontrafficprediction.Intheletter,FARIMA(p,d,q)modelsintheadmissioncontrolalgorithmisdeployed.AmethodtosimplifytheFARIMAmodelfittingprocedureandhencetoreducethetimeoftrafficmodelingandpredictionissuggested.Thefeasibility-studyexperimentsshowthatFARIMAmodelswhichhavelessnumberofparameterscanbeusedtomodelandpredictactualtrafficonquitealargetimescale.Simulationresultsvalidatethepromisingapproach.

  • 标签: 接纳控制 网络用户 服务质量 通信量 预测
  • 简介:SurvivabilityisoneoftheimportantissuesinATM-basednetworkssineevenasinglenetworkelementfailuremaycauseaseriousdataloss.Thispaperintroducesanewrestorationmechanismbasedonmulti-layerATMsurvivablenetworkmanagementarchitecture.ThismechanismintegratesthegeneralcontrolandrestorationcontrolbyestablishingtheWorkingVPslogicalnetwork,BackupVPslogicalnetworkandsparelogicalnetworkinordertooptimallyutilizethenetworkresourceswhilemaintainingtherestorationrequirements.

  • 标签: 异步传输模式 可生存性 恢复 集中控制
  • 简介:Aclassoflarge-sealesystems,wheretheoverallobjectivefunctionisanonlinearfunctionofperformanceindexofeachsubsystem,isinvestigatedinthispaper.Thistypeoflarge-scalecontrolproblemisnon-separableinthesenseofconventionalhierarchicalcontrol.Hierarchicalcontrolisextendedinthepapertolarge-scalenon-separablecontrolproblems,wheremultiobjectiveoptimizationisusedasseparationstrategy.Thelarge-scalenon-separablecontrolproblemisembedded,under;ertainconditions,intoafamilyoftheweightedLagrangianformulation.TheweightedLagrangianformulationisseparablewithrespecttosubsystemsandcanbeeffectivelysolvedusingtheinteractionbalanceapproachatthetwolowerlevelsintheproposedthree-levelsolutionstructure.Atthethirdlevel,theweightingvectorfortheweightedLagrangianformulationisadjustediterativelytosearchtheoptimalweightingvectorwithwhichtheoptimaloftheoriginallarge-scalenon-separablecontrolproblemisobtained.Theoreticalbaseofthealgorithmisestablished.Simulationshowsthatthealgorithmiseffective.

  • 标签: LARGE-SCALE system HIERARCHICAL control MULTI-OBJECTIVE optimization.