学科分类
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6 个结果
  • 简介:Nearfieldcommunications(NFC)isanewlythrivedtechnologyinrecentyears.Thistechnologyhasbeeninstalledonmanykindsofmobilephonesystems,especiallytheAndroid.However,thereisnounifiedandcompleteframeworktoaccessNFCsofar.ThecurrentsoftwarestackofNFCmerelyimplementsdataobtainingfeatures,ignoringthepost-processingofdataandlackingacertainsecuritymechanismforNFC,whichresultsininefficiencyandinconvenienceforsoftwaredevelopmentandmaintenance.Aboveall,securityproblemscouldbecausedduetotheabsenceofthesecuritymechanism.Toproposeasolution,thispaperpresentsabrand-newframeworkforNFCutilizationbyanalyzingandconstructingaservicemodel.Thus,theproposedframeworkencapsulatesthecurrentNFCstackonAndroid,formulatingathree-layerstructureafterimplementingtheencapsulationandparsingofNFCrecords,whichultimatelyenablesanXMLdocumenttodescribetheconfigurationofNFCanditsrelatedserviceflow.Simultaneously,acontext-awarenessmodelisproposedandbuiltinthispapertoequiptheframeworkwiththecapabilityofadaptingtodifferentphysicalenvironment.

  • 标签: NFC 框架 服务模式 堆栈 安全机制 软件开发
  • 简介:Agoodmodelcanextractusefulinformationaboutthetarget'sstatefromobservationseffectively.Therearemanymodelsusedtotrackinga,maneuveringtargetsuchasconstant-velocity(CV)model,Singeraccelerationmodel(zero-meanfirst-orderMarkovmodel)andcurrentmodel(mean-adaptiveaccelerationmodel),etc.Whileduetothecomplexityofmaneuveringtarget,toseekthetargetmodelwhichcangetbetterperformanceisstillasubjectworthyofstudy.BasedonstatisticsrelationbetweentheautocorrelationfunctionandthecovarianceofMarkovrandomprocessing,thispaperdevelopsamodelwhichcanadaptivelyadjustsystemparametersonline.Simulationsshowthegoodestimationperformancegetbythemodeldevelopedhere,andcomparingCV,Singerandcurrentmodels,themodelcanadaptivelygetthemodelparameterwhiletrackingthetrajectoryandneedn'tdoingseveralteststoobtainaprioriparameter.

  • 标签: 自适应模型 机动目标跟踪 统计模型 马尔可夫模型 跟踪机动目标 加速模型
  • 简介:Fieldcomputation,anemergingcomputationtechnique,hasinspiredpassionofintelligencescienceresearch.Anovelfieldcomputationmodelbasedonthemagneticfieldtheoryisconstructed.Theproposedmagneticfieldcomputation(MFC)modelconsistsofafieldsimulator,anon-derivativeoptimizationalgorithmandanauxiliarydataprocessingunit.ThemathematicalmodelisdeducedandprovedthattheMFCmodelisequivalenttoaquadraticdiscriminantfunction.Furthermore,thefiniteelementprototypeisderived,andthesimulatorisdeveloped,combiningwithparticleswarmoptimizerforthefieldconfiguration.Twobenchmarkclassificationexperimentsarestudiedinthenumericalexperiment,andonenotableadvantageisdemonstratedthatlesstrainingsamplesarerequiredandabettergeneralizationcanbeachieved.

  • 标签: 计算模型 磁场理论 模式分类 数据处理单元 二次判别函数 粒子群优化
  • 简介:Asatypicalcleanandrenewableenergy,windpowerisbecomingmoreandmorewidelyusedinelectricalindustry.However,itscharacteristicsofrandomandintermittenthavebroughtseriousproblemstothepowersystem,suchasvoltagefluctuationandinsufficientreactivepower.BasedontheK-meansclusteringalgorithm,thispaperclassifiesthedoubly-fedinductiongenerators(DFIG)accordingtotheoperationofpropellerpitchanglecontrol.Atthesametime,toobtaintheoptimalparameter,advancedparticleswarmoptimization(PSO)isused.ThenthedynamicmodelofDFIGunderthenetworkfaultconditionisbuilt.Whatismore,therolethatcrowbarcircuitplaysinlowvoltageridethrough(LVRT)isdiscussed.Finally,simulationsinDigSILENTverifythemodel.

  • 标签: 风力发电 低电压 能力模型 双馈电机 K-均值聚类算法 双馈感应发电机
  • 简介:Thisarticlepresentsadatamanagementsolutionbasedonthedatadistributionservice(DDS)communicationmodel.ThebasicDDScommunicationmodelconsistsofaunidirectionaldataexchangewhereapplicationsthatpublishdata'push'therelevantdata,whichisupdatedtothelocalcachesofco-locatedsubscriberstothedata[1].DDShasnospecifiedcenternodetoforwarddatapacketsandmaintainthecommunicationdata.Thistypeofpublish-subscribe(P/S)modelpresentsintegrityandconsistencychallengesindatamanagement.Unlikepeer-to-peer(P2P)distributedstorage,DDSapplicationshaveahardreal-timeenvironmentandfewerdatafeatures,andthecoreproblemisensuringtheintegrityandconsistencyofdataindistributedsystemsunderthishardreal-timeenvironment.ThisarticlebeginswithabriefintroductionofthecommunicationmodelusedbyDDS,thenanalyzespersistentdatamanagementproblemscausedbysuchmodel,andprovidesanappropriatesolutiontotheseproblems.Thissolutionhasbeenimplementedinaprototypesystemofthereal-timeservicebus(RTSB)ofTsinghuaUniversity.

  • 标签: 通信模型 数据管理 分发服务 数据分配 基础 应用程序
  • 简介:Usingultrashort-pulseradarwithcompactvivaldiantennas,thesimulationexperimentofbreastcancerdetectionhasbeenperformedinasyntheticbreastphantom.Twometallicballswith9mmand6mmindiameterareusedastumorsinourexperiment.Theimagereconstructionsofthebreastmodelswithtumorsusingreflectiondatahavebeenpresentedbyaconfocalmicrowaveimagingtechnique.Themethodcanbeusedforapulsecompressiontechniquetoreflectedwavesforclearimageformation.

  • 标签: 超短脉冲 乳腺癌 雷达系统 乳房 假体 合成