简介:为越过在象文件同步那样的应用程序的宽区域网络(广域网)的文件通讯的数据deduplication并且云环境反射通常完成以数据deduplication的重要时间开销的成本节省的重要带宽。时间开销包括在二个地理上分布式的节点为数据deduplication要求的时间(例如,磁盘存取瓶颈)并且在发送者之间的复制质问/答案操作和接收装置,后来,每询问或答案介绍至少一个潜伏的双程的时间(RTT)。在这份报纸,我们在场越过有元数据反馈和元数据利用(MFMU)的广域网的一个数据deduplication系统,联系了时间开销以便利用数据deduplication。在建议MFMU系统,到发送者的从接收装置的选择元数据反馈被介绍减少复制质问/答案操作的数字。另外,到马具,元数据在接收装置联系了磁盘I/O操作,以及带宽开销由元数据反馈介绍了,磁滞现象哈希值重新组合机制基于的元数据利用部件被介绍。我们的试验性的结果证明MFMU与保存没被元数据反馈减少的比率的带宽完成了20%40%deduplication加速的一般水准,当与基线相比内容定义组合(CDC)在LBFS(Low-bandwith网络文件系统)使用,组合算法的退出的最先进的Bimodal基于数据deduplication解决方案。
简介:Invideoinformationretrieval,keyframeextractionhasbeenrecognizedasoneoftheimportantresearchissues.Althoughmuchprogresshasbeenmade,theexistingapproachesareeithercomputationallyexpensiveorineffectiveincapturingsalientvisualcontent.Inthispaper,wefirstdiscusstheimportanceofkeyframeextractionandthenbrieflyreviewandevaluatetheexistingapproaches.Toovercometheshortcomingeoftheexistingapproaches,weintroduceanewalgorithmforkeyframeextractionbasedonunsupervisedclustring.Meanwhile,weprovideafeedbackchaintoadjustthegranularityoftheextractionresult.Theproposedalgorithmisbothcomputationallysimpleandabletocapturethevisualcontent.Theefficiencyandeffectivenessarevalidatedbylargeamountofreal-worldvideos.
简介:ThefeedbackstabilizationproblemofanonuniformTimoshenkobeamsystemwithrotorinertiaatthetipofthebeamisstudied.First,asaspecialkindoflinearboundaryforcefeedbackandmomentcontrolisappliedtothebeam'stip,thestrictmathematicaltreatment,asuitablestateHilbertspaceischosen,andthewell-posenessofthecorrespondingclosedloopsystemisprovedbyusingthesemigrouptheoryofboundedlinearoperators.Thentheenergycorrespondingtotheclosedloopsystemisshowntobeexponentiallystable.Finally,inthespecialcaseofuniformbeam,somesufficientandnecessaryconditionsforthecorrespondingclosedloopsystemtobeasymptoticallystablearederived.
简介:WeinvestigatetheexponentialstabilityinthemeansquaresenseforthesystemswithMarkovianswitchingandimpulseeffects.BasedonthestatisticpropertyoftheMarkovprocess,astabilitycriterionisestablished.Then,bytheparameterizationsviaafamilyofauxiliarymatrices,thedynamicaloutputfeedbackcontrollercanbesolvedviaanLMIapproach,whichmakestheclosed-loopsystemexponentiallystable.Anumericalexampleisgiventodemonstratethemethod.
简介:Pseudospectral(PS)computationalmethodsfornonlinearconstrainedoptimalcontrolhavebeenappliedtomanyindustrial-strengthproblems,notably,therecentzero-propellant-maneuveringoftheinternationalspacestationperformedbyNASA.Inthispaper,weproveatheoremontherateofconvergencefortheoptimalcostcomputedusingaLegendrePSmethod.Inadditiontothehigh-orderconvergencerate,twotheoremsareprovedfortheexistenceandconvergenceoftheapproximatesolutions.RelativetoexistingworkonPSoptimalcontrolaswellassomeotherdirectcomputationalmethods,theproofsdonotusenecessaryconditionsofoptimalcontrol.Furthermore,wedonotmakecoercivitytypeofassumptions.Asaresult,thetheorydoesnotrequirethelocaluniquenessofoptimalsolutions.Inaddition,arestrictiveassumptionontheclusterpointsofdiscretesolutionsmadeinexistingconvergencetheoremsisremoved.
简介:In4-strokeinternalcombustionengines,air-fuelratiocontrolisachallengingtaskduetotherapidchangesofenginethrottle,especiallyduringtransientoperation.Toimprovethetransientperformance,managingthecycle-to-cycletransientbehaviorofthemassoftheair,thefuelandtheburntgasisakeyissueduetotheimbalanceofcycliccombustionprocess.Thispaperaddressthemodel-basedestimationandcontrolproblemforcyclicair-fuelratioofspark-ignitionengines.Adiscrete-timemodelofair-fuelratioisproposed,whichrepresentsthecycle-to-cycletransientbehaviorofin-cylinderstatevariablesundertheassumptionsofcyclicmeasurabilityofthetotalin-cylinderchargemass,combustionefficiencyandtheresidualgasfraction.Withthemodel,aKalmanfilter-basedair-fuelratioestimationalgorithmisproposedthatenableustoperformafeedbackcontrolofair-fuelratiowithoutusinglambdasensor.Finally,experimentalvalidationresultisdemonstratedtoshowtheeffectivenessofproposedestimationandcontrolschemethatisconductedonafull-scaledgasolineenginetestbench.
简介:ThestatefeedbackdesignforsingularlyperturbedsystemsdescribedinDeltaoperatorisconsidered.Thecompositestatefeedbackcontrollerforslowandfastsubsystemsisdesignedbyusingthedirectmethod.TheobtainedresultscanbringpreviousconclusionsofcontinuousanddiscretetimesystemsintotheunifiedDeltaframework.Asimulationexampleispresentedtodemonstratethevalidityandefficiencyofthedesign.
简介:Wediscusstheglobalstabilizationprocedurewhichrendersageneralclassoffeedbacknonlinearsystemsexponentialconvergent.Ourstabilizerconsistsofanestedsaturationfunction,whichisanonlinearcombinationofsatrrationfunctions.Hereweprovetheexponentialconvergenceofthestabilizerforthefirsttimeandgivenumericalexamplestoillustratetheefficiencyoftheresultgivenabove.
简介:Thispaperinvestigatestheproblemofglobaloutputfeedbackstabilizationforaclassoffeedforwardnonlinearsystemsvialinearsampled-datacontrol.Tosolvetheproblem,wefirstconstructalinearsampled-dataobserverandcontroller.Then,ascalinggainisintroducedintotheproposedobserverandcontroller.Finally,weusethesampled-dataoutputfeedbackdominationapproachtofindtheexplicitformulaforchoosingthescalinggainandthesamplingperiodwhichrenderstheclosed-loopsystemgloballyasymptoticallystable.Asimulationexampleisgiventodemonstratetheeffectivenessoftheproposeddesignprocedure.