简介:TherobustH∞controlfornetworkedcontrolsystemswithbothstochasticnetwork-induceddelayanddatapacketdropoutisstudied.Whendataaretransmittedovernetwork,thestochasticdatapacketdropoutprocesscanbedescribedbyatwo-stateMarkovchain.Thenetworkedcontrolsystemswithstochasticnetwork-induceddelayanddatapacketdropoutaremodeledasadiscretetimeMarkovjumplinearsystemwithtwooperationmodes.ThesuffcientconditionofrobustH∞controlfornetworkedcontrolsystemsstabilizedbystatefeedbackcontrollerispresentedintermsoflinearmatrixinequality.Thestatefeedbackcontrollercanbeconstructedviathesolutionofasetoflinearmatrixinequalities.Anexampleisgiventoverifytheeffectivenessofthemethodproposed.
简介:Akindofnetworkedcontrolsystemisstudied;thenetworkedcontrolsystemwithnoisedisturbanceismodeledbasedoninformationschedulingandcontrolco-design.Augmentedstatematrixanalysismethodisintroduced,androbustfault-tolerantcontrolproblemofnetworkedcontrolsystemswithnoisedisturbanceunderactuatorfailuresisstudied.Theparametricexpressionofthecontrollerunderactuatorfailuresisgiven.Furthermore,theresultisanalyzedbysimulationtests,whichnotonlysatisfiesthenetworkedcontrolsystemsstability,butalsodecreasesthedatainformationnumberinnetworkchannelandmakesfulluseofthenetworkresources.
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简介:Inthispaper,aphotoelectricdeviceisintroduced,whichisusedinde-tectingthequalityoninternalsurfaceofthinandlongsteelpipe.Inthisdevice,theCCTVlensisusedforextracttheflawinformationoninternalsurfaceofthepipe,andmakeIBM-PC/AT486computerascontrollingandimageprocessingsystem.Bythisinstrument,thefunctions,suchasthedigitalconversiongofinputinformation,imageprocessing,classificationofrecognitionandoutputdisplaycanbeobtained,Inthepetroleumandchemicalindustry,byusingthisapparatus,wecandetectthequalithoninternalsurfaceofvariousmetalpipeswithreal-timeautomatically.
简介:ThispaperdescribesafullchannelTVmodulatorforallTVsystems,whichhasbeendevelopedsuccessfully.ItemploysadvancedtechniquesuchasPLLfrequencysynthesizerwithmicrowaveintegratedcircuit,andwidebandmicrostripVCOanddigital-analogcombinedintegratedcircuits.Thekeytechniqueofthemodulatorissettledsuccessfully.AllthespecificationsofthemodulatoragreewithTechnicalStandardofChina,whicharetestedbytheauthorityofChina.
简介:ThepurecubicGaN(c-GaN)hasbeengrownon(001)GaAssubstratesbyECR-PAMOCVDtechniqueatlowtemperatureusingTMGaandhighpureN2asGaandNsources,respectively.TheeffectsofsubstratepretreatmentconditionsonqualityofcubicGaNepilayerareinvestigatedbythemeasurementsofTEMandXRD.Itisfoundthathydrogenplasmacleaning,nitridationandbufferlayergrowthareveryimportantforqualityofcubicGaNepilayer.
简介:InordertoevaluatetheimagingqualityofCCDcamerasfullyandrapidly,theminimumresolvablecontrast(MRC)ispresentedinthispaperandthesystemofmeasuringMRCisconstructedaswell,inwhichtwointegratingspheresareproposedtoilluminatetwosidesofthetargetrespectively.Thevariablecontrastcanbeobtainedbyregulatingtheluminanceofintegratingspheres.Experimentalresultsindicatethattheerrorofmeasuringluminanceiswithin±0.3cd/m2,MRCriseswiththeincreaseofthespatialfrequency.TheexperimentalresultsshowthatthemethodproposedisaneffectiveapproachtoevaluatetheimagingqualityofCCDcameras.
简介:Theimpactanglecontroloverguidance(IACG)lawagainststationarytargetsisproposedbyusingfeedbacklinearizationcontrol(FLC)andfinitetimecontrol(FTC).First,thispapertransformsthekinematicsequationofguidancesystemsintothefeedbackablelinearizationmodel,inwhichtheguidancelawisobtainedwithoutconsideringtheimpactangleviaFLC.Forthepurposeofthelineofsight(LOS)angleanditsrateconvergingtothedesiredvalues,thesecond-orderLOSangleisconsideredasadouble-integralsystem.Then,thispaperutilizesFTCtodesignacontrollerwhichcanguaranteethestatesofthedouble-integralsystemconvergingtothedesiredvalues.NumericalsimulationillustratestheperformanceoftheIACG,incontrasttotheexistingguidancelaw.
简介:Objectivevideoqualityassessmentmethodsoftenevaluatealltheframesregardlessoftheirimportance.Forwirelessdistortedvideos,noteveryframehasthesamecontributiontothefinaloverallqualityduetothechannelfadingandinterference,whichmayleadtothecapacityvariationintemporal.Besides,withthecontentsimilarityanderrorpropagationpatternintemporaldomain,itispossibletoevaluatetheoverallqualitywithonlypartoftheframes.Inthispaper,ademonstrationisperformedtoshowthatthevideoqualitycanbeevaluatedwithreducedframesset(RFS),andastatetransitionmodelisproposedtoextracttheRFS.Atlast,avideoqualityassessment(VQA)methodiscarriedoutbasedonRFS.Comparedwithseveralstate-of-the-artmethods,ourmethodcanachieveasuitableaccuracywithlessframestobeprocessed.
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.
简介:ThisletteranalyzesthereasonswhytheknownNeuralBackPromulgation(NBP)networklearningalgorithmhasslowerspeedandgreatersampleerror.Basedontheanalysisandexperiment,thetraininggroupdescendingEnhancedCombinationAlgorithm(ECA)isproposed.TheanalysisofthegeneralizedpropertyandsampleerrorshowsthattheECAcanheightenthestudyspeedandreduceindividualerror.
简介:Oneofthemaindriversforintelligenttransportationsystemsissafety.Adaptivecruisecontrol,asacommonsolutionfortrafficsafety,hasextendedfromradarstocameras.Duetohighmobilityofvehiclesandunevennessofroads,thepicturequalityofcamerashasbeengreatchallengesforcamera-basedadaptivecruisecontrol.Inthispaper,animagedistortioncorrectionalgorithmisaddressed.Ourmethodisbasedonopticalflowtechnologywhichisnormallyappliedinmotionestimationandvideocompressionresearch.Wearethefirsttoattempttoadaptitinimagedistortioncorrection.Twoopticalflowapproaches,theLucas-KanademethodandtheHorn-Schunckmethod,areselectedandcompared.Theprocedureofimagedistortioncorrectionusingtheopticalflowmethodhasbeentestedbybothsynthetictestimagesandcameraimages.TheexperimentalresultsshowthattheLucas-Kanademethodismoresuitableinthecorrectionofimagedistortion.
简介:Inordertoformanemergencycontrolpolicytablequickly,thispaperproposesafastalgorithmofemergencycontrolnamed'micro-stepdiscretemethod',whichisbasedonthephysicalmeaningofthegradientandthediscretecharacteristicsofemergencycontrol.Thenitisimprovedthroughthestabilitycriterion,integralstep,andmicro-stepfactor.Thispapertakesgenerator-sheddingastheemergencycontrolmeasures.Astheoptimalgenerator-sheddingcontrolisessentiallyanoptimalcontrolproblemandthegenerator-sheddingvariablesarealwaysconstant,itisconvenienttousethecontrolparameteralgorithmtosolvetheproblem,whichcancalculatethegradientofthetransientstabilityfunctiontocontrolvariables.
简介:AdmissioncontrolplaysanimportantroleinprovidingQoStonetworkusers.Motivatedbythemeasurement-basedadmissioncontrolalgorithm,thisletterproposedanewadmissioncontrolapproachforintegratedservicepacketnetworkbasedontrafficprediction.Intheletter,FARIMA(p,d,q)modelsintheadmissioncontrolalgorithmisdeployed.AmethodtosimplifytheFARIMAmodelfittingprocedureandhencetoreducethetimeoftrafficmodelingandpredictionissuggested.Thefeasibility-studyexperimentsshowthatFARIMAmodelswhichhavelessnumberofparameterscanbeusedtomodelandpredictactualtrafficonquitealargetimescale.Simulationresultsvalidatethepromisingapproach.
简介:SurvivabilityisoneoftheimportantissuesinATM-basednetworkssineevenasinglenetworkelementfailuremaycauseaseriousdataloss.Thispaperintroducesanewrestorationmechanismbasedonmulti-layerATMsurvivablenetworkmanagementarchitecture.ThismechanismintegratesthegeneralcontrolandrestorationcontrolbyestablishingtheWorkingVPslogicalnetwork,BackupVPslogicalnetworkandsparelogicalnetworkinordertooptimallyutilizethenetworkresourceswhilemaintainingtherestorationrequirements.
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.