简介:Unmannedaerialvehicles(UAVs)mayplayanimportantroleindatacollectionandoffloadinginvastareasdeployingwirelesssensornetworks,andtheUAV’sactionstrategyhasavitalinfluenceonachievingapplicabilityandcomputationalcomplexity.Dynamicprogramming(DP)hasagoodapplicationinthepathplanningofUAV,butthereareproblemsintheapplicabilityofspecialterrainenvironmentandthecomplexityofthealgorithm.BasedontheanalysisofDP,thispaperproposesahierarchicaldirectionalDP(DDP)algorithmbasedondirectiondeterminationandhierarchicalmodel.WecompareourmethodswithQ-learningandDPalgorithmbyexperiments,andtheresultsshowthatourmethodcanimprovetheterrainapplicability,meanwhilegreatlyreducethecomputationalcomplexity.
简介:Operationalsoftwaresystemsoftenexperiencean'aging'phenomenon,characterizedbyprogressiveperformancedegradationandasuddenhang/crashfailure.Softwarerejuvenationisaproactivefault-tolerancestrategyaimedtopreventunexpectedoutagesduetoaging.Anewrejuvenationstrategybasedonmeasurementandtime,andconstructsaSRNmodeltoevaluatethisstrategy.Numericalresultsshowthatthisstrategyoutweighseitherthepurelymeasurementbasedorthepurelytime-basedstrategyandcaneffectivelyimprovesystemperformance.
简介:Aswitchingvariabilityindex(SVI)constantfalsealarmrate(CFAR)detectorisproposedforimprovingthedetectionperformanceofVI-CFARdetectorsinmultipletargetsbackgrounds.Whenthepresenceofnon-homogeneityinCFARreferencewindowsisindicatedbyaVI-CFARdetector,aswitchingCFARdetectorisintroducedtooptimizetheperformanceoftheVI-CFARdetectorinhomogeneous,multipletargetsandclutteredgebackgrounds.ThestructureandparametersselectionmethodoftheSVI-CFARdetectorispresented.ComparisonswithclassicCFARdetectorsandrecentlyproposeddetectorsarealsogiven.TheoreticalanalysisandsimulationresultsshowthatSVICFARdetectormaintainsthegoodperformanceoftheVI-CFARdetectorinhomogeneousandclutteredgebackgrounds,whilegreatlyimprovingthecapacityofanti-multitargets.
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:InvehicleAd-hocnetwok(VANET),trafficloadisoftenunevenlydistributedamongaccesspoints(APs).Suchloadimbalancehampersthenetworkfromfullyutilizingthenetworkcapacity.Toalleviatesuchimbalance,thepaperintroducesanovelpricinggamemodel.Theresearchsceneisattheintersectionwhenthetrafficlightisgreen.Asvehiclesarehighlymobileandthenetworktypologychangesdynamically,thepaperdividesthegreenlighttimeintoequalslotsandcalculatesAPs'priceswiththepresentedpricinggameineachtimeslot.Thewholeprocessisarepeatedgamemodel.ThefinalequilibriumsolutionsetisAPs'pricingstrategy,andthepaperclaimthatthisequilibriumsolutionsetcanaffectvehicles'selectionandensureAPs'load-balancing.Simulationresultsbasedonarealisticvehiculartrafficmodeldemonstratetheeffectivenessofthegamemethod.
简介:WhiletheNetworkCodingcooperativerelaying(NC-relaying)hasthemeritofhighspectralefficiency,SuperpositionCodingrelaying(SC-relaying)hasthemeritofhighthroughput.Inthispaper,anovelconcept,codedcooperativerelaying,ispresented,whichisaunifiedschemeoftheNC-relayingandSC-relaying.FortheSC-relayingstrategywhichcanbeconsideredone-waycodedrelayingschemewithmulti-accesschannel,theclose-formsolutionoftheoutageprobabilitiesofthebasicsignalandadditionalsignalareobtainedfirstly.Secondly,theDiversity-and-MultiplexingTradeoff(DMT)characteristicsofbasicsignalandadditionalsignalareinvestigatedentirelyaswellastheoptimalclose-formsolutions.Thecomparednumericalanalysisshowstheevaluationerrorofthroughputbasedontheclose-formsolutionisabout0.15nats,whichiswithintheacceptableerrorrange.Duetothemutualeffectbetweenthebothsourcesignals,theavailablemaximalvaluesofthetwomultiplexinggainsarelessthan1.
简介:Makingfulluseofwindpowerisoneofthemainpurposesofthewindturbinegeneratorcontrol.Conventionalhillclimbingsearch(HCS)methodcanrealizethemaximumpowerpointtracking(MPPT).However,thestepsizeofHCSmethodisconstantsothatitcannotconsiderbothsteady-stateresponseanddynamicresponse.Afuzzylogicalcontrol(FLC)algorithmisproposedtosolvethisprobleminthispaper,whichcantrackthemaximumpowerpoint(MPP)quicklyandsmoothly.ToevaluateMPPTalgorithms,fourperformanceindicesarealsoproposedinthispaper.Theyaretheenergycapturedbywindturbine,themaximumpower-pointtrackingtimewhenwindspeedchangesslowly,thefluctuationmagnitudeofrealpowerduringsteadystate,andtheenergycapturedbywindturbinewhenwindspeedchangesfast.ThreecasesaredesignedandsimulatedinMATLAB/Simulinkrespectively.ThecomparisonofthethreeMPPTstrategiesconcludesthattheproposedfuzzylogicalcontrolalgorithmismoresuperiortotheconventionalHCSalgorithms.
简介:Aseachtypeofsatellitenetworkhasdifferentlinkfeatures,itsdatatransmissionmustbedesignedbasedonitslinkfeaturestoimprovetheefficiencyofdatatransferring.Thetransmissionofnavigationintegratedservicesinformation(NISI)inaglobalnavigationsatellitesystem(GNSS)withinter-satellitelinks(ISLs)isstudiedbytakingtherealsituationofinter-satellitecommunicationlinksintoaccount.Anon-demandcomputingandbufferingcentralizedroutestrategyisproposedbasedondynamicgroupingandthetopologyevolutionlawoftheGNSSnetworkwithinwhichthesatellitenodesareoperatedinthemannerofdynamicgrouping.Dynamicgroupingisbasedonsatellitesspatialrelationshipsandthegrouproleofthesatellitenodechangesbyturnsduetoitsspatialrelationships.Theroutestrategyprovidessignificantadvantagesofhighefficiency,lowcomplexity,andflexibleconfiguration,bywhichtheestablishedGNSScanpossessthefeaturesandcapabilitiesoffeasibledeployment,efficienttransmission,convenientmanagement,structuralinvulnerabilityandflexibleexpansion.
简介:Withthedevelopmentofsmartgrid,residentshavetheopportunitytoscheduletheirhouseholdappliances(HA)forthepurposeofreducingelectricityexpensesandalleviatingthepressureofthesmartgrid.Inthispaper,weintroducethestructureofhomeenergymanagementsystem(EMS)andthenproposeapoweroptimizationstrategybasedonhouseholdloadmodelandelectricvehicle(EV)modelforhomepowerusage.Inthisstrategy,theelectricvehiclesarechargedwhenthepriceislow,andotherwise,aredischarged.Byadoptingthiscombinedsystemmodelunderthetime-of-useelectricityprice(TOUP),theproposedschedulingstrategywouldeffectivelyminimizetheelectricitycostandreducethepressureofthesmartgridatthesametime.Finally,simulationexperimentsarecarriedouttoshowthefeasibilityoftheproposedstrategy.Theresultsshowthatcrossovergeneticparticleswarmoptimizationalgorithmhasbetterconvergencepropertiesthantraditionalparticleswarmalgorithmandbetteradaptabilitythangeneticalgorithm.
简介:Afundamentalissueinopticalburstswitching(OBS)networksistosolvetheburstcontentionforthecorenode.Inthispaper,anovelpriority-basedcontentionsolutionstrategyforOBSnetworksisproposed.Whenthecontentionoccurs,theburstpriorityisconsideredfirstly,andthentheburstsegmentationmethodisusedforthelowpriorityburstsinthisstrategy.Ensuringtheintegrityofhighprioritybursts,partofthesegmentedburstscanbetransmittedtothedestinationnodeviacombiningwavelengthconversionandopticalbuffermethod.Simulationresultsshowthattheproposedschemenotonlyensurestheintegrityofhighprioritybursts,butalsoreducesthepacketlossrateofthelowpriorityburstsmaximally,sothatitcansupportgoodqualityofservice(QoS)forthenetwork.
简介:Inthispaper,anovelframework,namedasglobal-localfeatureattentionnetworkwithrerankingstrategy(GLAN-RS),ispresentedforimagecaptioningtask.Ratherthanonlyadoptingunitaryvisualinformationintheclassicalmodels,GLAN-RSexplorestheattentionmechanismtocapturelocalconvolutionalsalientimagemaps.Furthermore,weadoptrerankingstrategytoadjustthepriorityofthecandidatecaptionsandselectthebestone.TheproposedmodelisverifiedusingtheMicrosoftCommonObjectsinContext(MSCOCO)benchmarkdatasetacrosssevenstandardevaluationmetrics.ExperimentalresultsshowthatGLAN-RSsignificantlyoutperformsthestate-of-the-artapproaches,suchasmultimodalrecurrentneuralnetwork(MRNN)andGoogleNIC,whichgetsanimprovementof20%intermsofBLEU4scoreand13pointsintermsofCIDERscore.
简介:与增加的精力消费,精力效率(EE)作为光谱效率(SE)为无线通讯网络被看作了一个重要度量标准。在这份报纸,为downlink多用户的EE优化问题多重输入多重产量(MU-MIMO)有巨大的天线的系统被调查。根据凸的优化理论,在那里存在完成最佳的EE的唯一的全球性最佳的电源分配,并且仅仅与隧道状态信息有关的最佳的EE靠近形式被导出经分解。然后,两个都,有不同复杂性的近似、精确的电源分配算法被建议完成最佳的EE。近似算法获得的最佳的EE与一致到在可控制的错误限制以内由精确算法完成了那的模拟结果表演,和这些建议算法比存在相等的电源分配算法更好表现。有在底的天线的数字的最佳的EE和相应SE增加驻扎无线通讯网络,它为下一代是有希望的。
简介:Inthispaper,wepresentasimplebutpowerfulensembleforrobusttextureclassification.Theproposedmethodusesasingletypeoffeaturedescriptor,i.e.scale-invariantfeaturetransform(SIFT),andinheritsthespiritofthespatialpyramidmatchingmodel(SPM).Inaflexiblewayofpartitioningtheoriginaltextureimages,ourapproachcanproducesufficientinformativelocalfeaturesandtherebyformareliablefeaturepondortrainanewclass-specificdictionary.Totakefulladvantageofthisfeaturepond,wedevelopagroup-collaborativelyrepresentation-basedstrategy(GCRS)forthefinalclassification.Itissolvedbythewell-knowngrouplasso.Butwegobeyondofthisandproposealocality-constraintmethodtospeedupthis,namedlocalconstraint-GCRS(LC-GCRS).Experimentalresultsonthreepublictexturedatasetsdemonstratetheproposedapproachachievescompetitiveoutcomesandevenoutperformsthestate-of-the-artmethods.Particularly,mostofmethodscannotworkwellwhenonlyafewsamplesofeachcategoryareavailablefortraining,butourapproachstillachievesveryhighclassificationaccuracy,e.g.anaverageaccuracyof92.1%fortheBrodatzdatasetwhenonlyoneimageisusedfortraining,significantlyhigherthananyothermethods.
简介:Inthispaper,weproposeatheoreticalmethodinordertoestimatetheforwardlinkoutageprobabilityandusercapacityofacellularsystemwhicharebasedonIS-95CDMAstandard,especialyimpactofpowercontrolstrategyandwiceactivitymonitoringinthesystemunderlong-termfadingeffects,inwhichthelightandheavyfadingsareconsidered.Accordingtothenumericalresultsobtainedinthispaper,thepowercontrolstrategyleadstoapproximatelythethreefoldusercapacityincontrasttothesituationwithoutpowercontrolstrategy,ThereultsarecomparedwithInterference-to-SignalRatio(ISR)drivenpowercontrolscheme^[6][9]whichcanbeusedonlyforsimulationofthesystem.Thepowercontrolstrategynotonlyimprovesthedesiredsignaltotheinterferencerationinthereferenceuser'sreceiver,butalsooffersuniformservicetotheuserwhereveritislocatedinthecell.
简介:Femtocell是一种有希望的技术与低力量、费用有益的小基础车站改进网络性能。然而,在femtocell网络的干扰有限现实使干扰和资源管理成为钥匙到完成femtocell网络的好处。在这份报纸,下列贡献一步一步地被做:首先,根据在技术和第三产生合伙的网络建筑学投射的认知无线电(CR)(3GPP)的干扰温度模型(ITM),长期的进化进展了(LTE--一),优化再使用femtocell的子通道的能力的问题模型在划分策略的频率下面被建立,联合考虑平均干扰限制和即时干扰限制。第二,利用凸的理论,再使用femtocell的子通道的最佳的力量分配被导出。第三在使隧道褪色的瑞利下面,子通道的靠近形式的表情可重用的概率和能力被导出。最后,数字结果被进行到证实我们的分析结果,它能为femtocell网络推广的频率资源分配提供理论指导。