简介:[1]Ci,S.,Sharif,H.,2002.AVariableDataRateSchemetoEnhanceThroughputPerformanceofWirelessLANs.IEEECSNDSP.[2]Doufexi,A.,Armour,S.,Butler,M.,Nix,A.,Bull,D.,2001.AstudyoftheperformanceofHiperlan/2andIEEE802.11aphysicallayers.IEEEVTC,1:668-672.[doi:10.1109/VETECS.2001.944927][3]Doufexi,A.,Armour,S.,Karlsson,P.,Butler,M.,Nix,A.,Bull,D.,2002.AcomparisonoftheHiperlan/2andIEEE802.11aWirelessLANstandards.IEEECommunicationsMagazine,40(5):172-180.[doi:10.1109/35.1000232][4]Ferré,P.,Doufexi,A.,Chung-How,J.,Nix,A.,Bull,D.,2003.LinkAdaptationforVideoTransmissionoverCOFDMBasedWLANs.IEEESCVT.Eindhoven.[5]Girod,B.,Kalman,M.,Liang,Y.,Zhang,R.,2002.Advancesinchannel-adaptivevideostreaming.JournalofWirelessCommunicationsandMobileComputing,2(6):573-584.[doi:10.1002/wcm.87][6]Haratcherev,I.,Langendoen,K.,2004.HybridRateControlforIEEE802.11.ACMInternationalWorkshoponMobilityManagementandWirelessAccess(MobiWac),Philadelphia.[7]Haratcherev,I.,Langendoen,K.,Lagendijk,I.,Sips,H.,2002.D3.16:Application-directedAutomatic802.11RateControl.GigaMobileProject,TUDelf,Tech.Rep.[8]Haratcherev,I.,Langendoen,K.,Lagendijk,R.,Sips,H.,2004.SNR-basedRateControlinWaveLAN.ASCI2004Conference.PortZelande.[9]Haratcherev,I.,Taal,J.,Langendoen,K.,Lagendijk,R.,Sips,H.,2005.AutomaticIEEE802.11ratecontrolforstreamingapplications.WirelessCommunicationsandMobileComputing,5(4):421-437.[doi:10.1002/wcm.301][10]Hoffman,C.,Manshaie,M.H.,Turletti,T.,2005.CLARA:Closed-LoopAdaptiveRateAllocationforIEEE802.11WirelessLANs.IEEEWirelessCom'.Hawaii.[11]Holland,G.,Vaidya,N.,Bahl,P.,2001.ARate-AdaptiveMACProtocolforMulti-HopWirelessNetworks.Mobicom.Rome.[12]H264software,2005.H.264/AVCSoftwareCoordination.http://bs.hhi.de/~suehring/tml/.[13]IEEE802.11,1999.Part11:WirelessLANMediumAccessControl(MAC)andPhysicalLayer(PHY)Specifications.[14]IEEE802.11a,1999.Part11:WirelessLANMediumAccessControl(MAC)andPhysicalLayer(PHY)Specific
简介:高效地利用单个说明的性能为录像编码的多重数据(SIMD)体系结构,有power-of-two存储器模块的并联存储器体系结构被建议。扭曲计划在水平、垂直的方向提供没有冲突的存取给邻近的元素(8位和16位数据类型)或与power-of-two间隔采用二篇小说,它不在以前的并联存储器体系结构是可能的。区域消费和延期评价与4,8和16个记忆模块分别地被给。在一种0.18-μm互补金属氧化物半导体技术下面,当读了并且写潜伏时,合成结果证明建议系统能以19k门的成本与16个记忆模块完成230MHz钟频率分别地是3和2个钟周期。我们在一个录像信号处理器(VSP)上实现建议并联存储器体系结构。VSP与建议建筑学提高了的结果表演为H.264完成1.28×加速即时译码。
简介:Theauthordesignedtwoalgorithmsfordistributedcooperationamongmultiplevideostreamssharingcommoncommunicationresources.Thealgorithmstakeadvantageofanoptimizationframeworkthatcharacterizesvideopacketssuchthatjointresourceallocationcanbeimplementednotonlyoverthepacketsofasinglestream,butalsoacrosspacketsofdifferentstreams.Thefirstalgorithmenablescollaborationamongmultiplevideosendersinan802.11CSMA/CAwirelessnetworksuchthattheirjointperformanceismaximized.Viathealgorithm,theuserscooperativelyestablishtransmissionprioritiesbasedontheassignedcharacterizationsoftheirvideopackets.Thesecondtechniqueallowsforlow-complexityjointbandwidthadaptationofmultiplevideostreamsatintermediatenetworknodesintheIntemetinordertomaximizetheoverallnetworkperformance.Theauthoranalyzestheadvantagesoftheproposedalgorithmsoverconventionalsolutionsemployedinsuchscenarios.Itisshownthatdependingonsystemparameterssuchasavailablenetworkdataratetheproposedtechniquescanprovidesubstantialgainsinend-to-endperformance.
简介:Sportsvideoappealstolargeaudiencesduetoitshighcommercialpotentials.Automaticallyextractingusefulsemanticinformationandgeneratinghighlightsummaryfromsportsvideotofacilitateusers'accessingrequirementsisanimportantproblem,especiallyintheforthcomingbroadbandmobilecommunicationandtheneedforuserstoaccesstheirmultimediainformationofinterestfromanywhereatanytimewiththeirmostconvenientdigitalequipments.Inthispaper,asystemtogeneratehighlightsummariesorientedformobileapplicationsisintroduced,whichincludeshighlightextractionandvideoadaptation.Inthissystem,severalhighlightextractiontechniquesareprovidedforfieldsportsvideoandracketsportsvideobyusingmulti-modalinformation.Toenhanceusers'viewingexperienceandsavebandwidth,3Danimationfromhighlightsegmentisalsogenerated.Asanimportantproceduretomakevideoanalysisresultsuniversallyapplicable,videotranscodingtechniquesareappliedtoadaptthevideoformobilecommunicationenvironmentanduserpreference.Experimentalresultsareencouragingandshowtheadvantageandfeasibilityofthesystemformultimediacontentpersonalization,enhancementandadaptationtomeetdifferentuserpreferenceandnetwork/devicerequirements.
简介:Thispaperproposesanewadaptivepost-filteringalgorithmtoremovecodingartifactsinblock-basedvideocoder.Theproposedmethodconcentratesonblockingandringingartifactsremoval.Forde-blocking,theblockingstrengthisidentifiedtodeterminethefilteringrange,andthemaximumquantizationparameteroftheimageisusedtoadaptthe1Dfuzzyfilter.Forde-ringing,besidestheedgedetection,acomplementaryringingdetectionmethodisproposedtolocatetheneglectedringingblocks,andthegradientthresholdisadoptedtoadjusttheparameterof2Dfuzzyfilter.ExperimentsareperformedontheMPEG-4sequences.Comparedwithothermethods,theproposedoneachievesbetterdetailpreservationandartifactsremovalperformancewithlowercomputationalcost.
简介:WesolvetheproblemofuplinkvideostreaminginCDMAcellularnetworksbyjointlydesigningtheratecontrolandschedulingalgorithms.Inthepricing-baseddistributedratecontrolalgorithm,thebasestationannouncesapricefortheperunitaveragerateitcansupport,andthemobiledeviceschoosetheirdesiredaveragetransmissionratesbybalancingtheirvideoqualityandcostoftransmission.Eachmobiledevicethendeterminesthespecificvideoframestotransmitbyavideosummarizationprocess.Inthetime-division-multiplexing(TDM)schedulingalgorithm,thebasestationcollectstheinformationonframestobetransmittedfromalldeviceswithinthecurrenttimewindow,sortstheminincreasingorderofdeadlines,andschedulesthetransmissionsinaTDMfashion.Thisjointalgorithmtakesadvantageofthemulti-usercontentdiversity,andmaximizesthenetworktotalutility(i.e.,minimizethenetworktotaldistortion),whilesatisfyingthedeliverydeadlineconstraints.Simulationsshowedthattheproposedalgorithmsignificantlyoutperformstheconstantrateprovisionalgorithm.
简介:BymeansofthefrozentimeapproachandtheKroneckerproduct,twocriteriaofasymptoticstabilityarederivedforthelinear,timevariantdynamicsystemswitheithershorttimedelaysorwithweakfeedbackinvolvingarbitrarytimedelays,respectively.Itisfoundthattheasymptoticstabilityoftheseretardeddy-nainicsystemsisgovernedbythemaximalandminimalsingularvaluesofthecoeffi-cientmatricesandtheirtimederivatives.
简介:students'mathematicalunderstanding,theyarenotableyettomastertothenextdegree.Thedecreasingofstudents'MathqualitycanbeseenonthesurveydataonProgramforInternationalStudentAssessment(PISA)thatconductedeachofthreeyears.On2003,Indonesiawasinthe38^thfrom40stateswiththescore360.On2006,itwasin50thfrom57stateswiththescore391.
简介:Real-timevideotransportoverwirelessInternetfacesmanychallengesduetotheheterogeneousenvironmentincludingwirelineandwirelessnetworks.Arobustnetworkconditionclassificationalgorithmusingmultipleend-to-endmetricsandSupportVectorMachine(SVM)isproposedtoclassifydifferentnetworkeventsandmodelthetransitionpatternofnetworkconditions.End-to-endQuality-of-Service(QoS)mechanismslikecongestioncontrol,errorcontrol,andpowercontrolcanbenefitfromthenetworkconditioninformationandreacttodifferentnetworksituationsappropriately.TheproposednetworkconditionclassificationalgorithmusesSVMasaclassifiertoclusterdifferentend-to-endmetricssuchasend-to-enddelay,delayjitter,throughputandpacketloss-ratefortheUDPtrafficwithTCP-friendlyRateControl(TFRC),whichisusedforvideotransport.Thealgorithmisalsoflexibleforclassifyingdifferentnumbersofstatesrepresentingdifferentlevelsofnetworkeventssuchaswirelinecongestionandwirelesschannelloss.Simulationresultsusingnetworksimulator2(ns2)showedtheeffectivenessoftheproposedscheme.
简介:ThenewH.264videocodingstandardachievessignificantlyhighercompressionperformancethanMPEG-2.AstheMPEG-2ispopularindigitalTV,DVD,etc.,bandwidthormemoryspacecanbesavedbytranscodingthosestreamsintoH.264intheseapplications.Unfortunately,thehugecomplexitykeepstranscodingfrombeingwidelyusedinpracticalapplications.Thispaperproposesanefficienttranscodingarchitecturewithasmartdownscalingdecoderandafastmodedecisionalgorithm.Usingtheproposedarchitecture,hugebufferingmemoryspaceissavedandthetranscodingcomplexityisreduced.Performanceoftheproposedfastmodedecisionalgorithmisvalidatedbyexperiments.
简介:Timereversalisappliedtotheunderwaterspreadingspectrumcodingcommunication.Onthebaseofanalyzingthefocusingcharacteristicsofthetimereversalinunderwaterwaveguide,thetimereversalisstudiedtoovercomethewavedistortionoftheencodedsignalcausedbythemulti-patheffect.TheexperimentresearchforunderwatercodingcommunicationiscarriedoutinalabwatertankandthecorrespondingtheoreticalanalysisisalsoconductedbyBinaryPhaseShiftKeying(BPSK)encodingandBarkercodewith7chipsforthespreadingspectrumsignal.Theresultsshowthatthetimereversalcanimprovethefocusinggainandincreasetheratiooftheprincipaltothesecondlobeofthecodingsignal,andcandecreasethebiterrorrateandincreasethecommunicationdistance.
简介:InthispaertheinequalityofLemma1of[1]isextended.BymeansofourinequalityandthemethodofLyapunovfunctionwestudythestabilityoftwokindsoflargeseatedifferentialsystemswithtimelagandthestabilityofahigher-orderdifferentialequationwithtimelag.Thesufficientconditionsforthestability(S.),theasymptoticstability(A.S.),theuniformlyasymptoticstability(U.A.S)andtheexponentialasymptoticstability(E.A.S.)ofthezerosolutionsofthesystermsareobtainedrespectively.