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:Videoinlanguageteachingoffersexcitingpossi-bilitiestotrainlearners’communicativecompetence.Thisarticleintroducesfivedifferenttechniquesinus-ingvideointhelanguageclasssoastobringaboutin-teractionbetweenvideo,studentsandteacher.
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:Thispaperpresentsahumandetectionsysteminavision-basedhospitalsurveillanceenvironment.Thesystemiscomposedofthreesubsystems,i.e.backgroundsegmentationsubsystem(BSS),humanfeatureextractionsubsystem(HFES),andhumanrecognitionsubsystem(HRS).ThecodebookbackgroundmodelisappliedintheBSS,thehistogramoforientedgradients(HOG)featuresareusedintheHFES,andthesupportvectormachine(SVM)classificationisemployedintheHRS.Bymeansoftheintegrationofthesesubsystems,thehumandetectioninavision-basedhospitalsurveillanceenvironmentisperformed.Experimentalresultsshowthattheproposedsystemcaneffectivelydetectmostofthepeopleinhospitalsurveillancevideosequences.
简介:Traditionalbackgroundmodelmethodsoftenrequirecomplicatedcomputations,andaresensitivetoilluminationandshadow.Inthispaper,weproposeablock-basedbackgroundmodelingmethod,anduseourproposedmethodtocombinecolorandtexturecharacteristics.Suppressionandrelaxationarethetwokeystrategiestoresistilluminationchangesandshadowdisturbance.Theproposedmethodisquiteefficientandiscapableofresistingilluminationchanges.Experimentalresultsshowthatourmethodissuitableforreal-wordscenesandreal-timeapplications.
简介:Theauthordesignedtwoalgorithmsfordistributedcooperationamongmultiplevideostreamssharingcommoncommunicationresources.Thealgorithmstakeadvantageofanoptimizationframeworkthatcharacterizesvideopacketssuchthatjointresourceallocationcanbeimplementednotonlyoverthepacketsofasinglestream,butalsoacrosspacketsofdifferentstreams.Thefirstalgorithmenablescollaborationamongmultiplevideosendersinan802.11CSMA/CAwirelessnetworksuchthattheirjointperformanceismaximized.Viathealgorithm,theuserscooperativelyestablishtransmissionprioritiesbasedontheassignedcharacterizationsoftheirvideopackets.Thesecondtechniqueallowsforlow-complexityjointbandwidthadaptationofmultiplevideostreamsatintermediatenetworknodesintheIntemetinordertomaximizetheoverallnetworkperformance.Theauthoranalyzestheadvantagesoftheproposedalgorithmsoverconventionalsolutionsemployedinsuchscenarios.Itisshownthatdependingonsystemparameterssuchasavailablenetworkdataratetheproposedtechniquescanprovidesubstantialgainsinend-to-endperformance.
简介:录像加速器在分享象YouTube那样的网站的录像为更好的用户经验被开发。PPLive录像加速器(PPVA)在中国有用户的最大的数字,基于对等(P2P)系统。在PPVA的录像和同伴的数字由比哪个多次大的数量级在需求(VoD)上的传统的P2P录像系统。作为结果,尽管资源是足够的,由于不公平赋值,服务的质量几乎不能满足所有用户。在这份报纸,我们在PPVA专注于基本资源的任务:存储和带宽。存储赋值的问题作为一个随机的变量关于请求的数字作为一个非线性的程序(NLP)被提出。当平均数比变化大得多时,请求的变化的影响不是可以忽略、比例的途径的结果表演仅仅是适当的。关于怎么定位录像到适当同伴的标准也被介绍,考虑抑制例如全部的带宽,带宽竞争的概率和在录像之间的公平的利用。而且,分配的启发式的算法以集中、分布式的时尚上载带宽被建议并且在录像之中关于平衡与广泛地使用的策略(相等的分配)作比较。模拟结果证明两个算法能导致重要表演改进。
简介:UsingvideofilmscanbeaveryeffectivewayofteachingandlearningEnglishonlywhenthefilmsareproperlyselectedandsomeactivitiesareorganizedaroundthem.Thispaperoffersthecriteriaforchoosingfilmsandsuggestssomeactivitiesforavarietyoflanguageteachingpurposes.AsvideounitsandvideofilmsinEnglisharenowmoreeasilyavailable,theuseofvideofilmshasbecomeanincreasinglyimportantcomponentofteachingEnglishasaforeignlanguage.HereIusetheterm"videofilm"inaloosesensetomean"featurefilmonvideo".Inrecentyears,textbookshaveappearedinChina,suchasEnglishThroughFilms(WuQing,YangLimin1993)andEnglishandAmericanFilms
简介:Sportsvideoappealstolargeaudiencesduetoitshighcommercialpotentials.Automaticallyextractingusefulsemanticinformationandgeneratinghighlightsummaryfromsportsvideotofacilitateusers'accessingrequirementsisanimportantproblem,especiallyintheforthcomingbroadbandmobilecommunicationandtheneedforuserstoaccesstheirmultimediainformationofinterestfromanywhereatanytimewiththeirmostconvenientdigitalequipments.Inthispaper,asystemtogeneratehighlightsummariesorientedformobileapplicationsisintroduced,whichincludeshighlightextractionandvideoadaptation.Inthissystem,severalhighlightextractiontechniquesareprovidedforfieldsportsvideoandracketsportsvideobyusingmulti-modalinformation.Toenhanceusers'viewingexperienceandsavebandwidth,3Danimationfromhighlightsegmentisalsogenerated.Asanimportantproceduretomakevideoanalysisresultsuniversallyapplicable,videotranscodingtechniquesareappliedtoadaptthevideoformobilecommunicationenvironmentanduserpreference.Experimentalresultsareencouragingandshowtheadvantageandfeasibilityofthesystemformultimediacontentpersonalization,enhancementandadaptationtomeetdifferentuserpreferenceandnetwork/devicerequirements.