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78 个结果
  • 简介:ThenewH.264videocodingstandardachievessignificantlyhighercompressionperformancethanMPEG-2.AstheMPEG-2ispopularindigitalTV,DVD,etc.,bandwidthormemoryspacecanbesavedbytranscodingthosestreamsintoH.264intheseapplications.Unfortunately,thehugecomplexitykeepstranscodingfrombeingwidelyusedinpracticalapplications.Thispaperproposesanefficienttranscodingarchitecturewithasmartdownscalingdecoderandafastmodedecisionalgorithm.Usingtheproposedarchitecture,hugebufferingmemoryspaceissavedandthetranscodingcomplexityisreduced.Performanceoftheproposedfastmodedecisionalgorithmisvalidatedbyexperiments.

  • 标签: 图像通信 视频自动译码 代码转换机 电子技术
  • 简介:ThispaperproposesanadaptivejointsourceandchannelcodingschemeforH.264videomulticastoverwirelessLANwhichtakesintoaccounttheusertopologychangesandvaryingchannelconditionsofmultipleusers,anddynamicallyallocatesavailablebandwidthbetweensourcecodingandchannelcoding,withthegoaltooptimizetheoverallsystemperformance.Inparticular,sourceresilienceanderrorcorrectionareconsideredjointlyintheschemetoachievetheoptimalperformance.Andachannelestimationalgorithmbasedontheaveragepacketlossrateandthevarianceofpacketlossrateisproposedalso.Twooverallperformancecriteriaforvideomulticastareinvestigatedandexperimentalresultsarepresentedtoshowtheimprovementobtainedbythescheme.

  • 标签: MULTICAST OVER 802.11 WIRELESS local area
  • 简介:选用aug-cc-pVTZ及aug-cc-pVQZ基组对不同H2-H2位形进行了量子化学计算,外推出了氢分子间各向异性ab-initio作用势。依据实验数据确定出氢分子相互作用的5-体模型,在全局最优算法基础上拟合出了包含电四极矩项、多体极化作用项及三体关联项等在内的氢分子间各向异性作用势。结果验证了拟合势与ab-initio势能曲线几乎重合,两者偏差落在(-1.35K,1.29K)范围内;得出的氢分子第二维里系数与实验结果一致。

  • 标签: 氢分子 各向异性作用势 从头计算
  • 简介:分子的动态模拟被执行在交流上调查事件精力的效果:从C和HH电影生长原子流动。我们的模拟证明在低事件精力(1eV)的电影生长被H和C原子的吸附统治。在中等事件精力(10和20eV),有在表面吸附的H原子的事件H原子的抽象反应变得重要。在高事件精力(30和40eV),交流:H电影生长是一个二拍子的圆舞过程:一个人是吸附和C原子的浅培植,并且其它是H原子的深培植。[从作者抽象]

  • 标签: 分子动力学模拟 薄膜生长 入射能量 H原子 交流 流量
  • 简介:In2010,theBESCollaboration[1]foundaclearenhancementintheK0K0massdistributionintheJ=ψ!ηK0K0decay.SuchanenhancementisusuallyasignatureofanL=0resonancearoundthreshold,whichinthiscasewouldcorrespondstoanh1statewithquantumnumbersIG(JPC)=0??(1+??).Thish1statewaspredictedbytheChiralUnitarytheoryintheKKinteraction.Becauseoftheconversationlaw,thisstatecanonlydecaytoK0K0channel,andcanbestudiedefficientlyintheJ=ψ!ηK0K0decay.

  • 标签: SIGNATURE SIGNATURE QUANTUM CLEAR can BES
  • 简介:ConstructingareasonablereactionkineticmodelforCr-containingwasteincinerationisofhighsignificancetostudytheeffectofvariousfactors,suchastemperature,Cl,onitshexavalentchromiumcompounds.Inthispaper,aprimaryCr/H/Air/ClreactionkineticmodelisbuiltandstudiedbyGaussian03codewithquantumchemistrytheory.Numericalresultsshowthattherearetwooverallreactionsinthemodel,eachofthetwooverallreactionsconsistsoftheirrespectivetwoelementaryreactions.Sothetwooverallreactionsshouldbeomittedfromthemodel.Instead,thefourelementaryreactionsshouldbeaddedintheCr/H/Air/Clreactionkineticmodel.Theactivationenergiesofthefourelementaryreactionsarealsocalculated.

  • 标签: 动力学模型 高氯 空气 小时 反应活化能 CR
  • 简介:Experimentalresultsarepresentedforsuperfluid(HeⅡ)flowthroughporousplugliquid-vaporphaseseparators.Testshavebeenperformedonsevenporousplugswithdifferentthicknessesordifferentpermeabilities.Thetemperaturewasmeasuredfrom1.5Kto1.9K.Twoflowregionswereobservedinsmallandlargepressureandtemperaturedifferencesregionsrespectively.Theexperimentaldataarecomparedwiththeoreticalpredictions.Theperformanceandapplicabilityofthebasictheoryarediscussed.Hysteresisoftheflowrateisalsoobservedanddiscussed.

  • 标签: 超铃氦 超流体 流动率 液-气相位分离
  • 简介:AfterhavingevaluatedvariousH.323productsforthesetwoyears,KEKandJapaneseHENPcommunitystartedtomovefromISDN(H.320)-basedvideoconferencingenvironmentintoIP(H.323)-basedone.PrimaryreasonforthemoveistocutdowntheeverincreasingISDNcommunicationcost.AtthesametimetheH.323canofferusmorepowerfulcollaborativeenvironment.InordertomakeKEKtobeacenterfortheH.323-basedcollaborativeenvironmentinJapan,PictureTel'sLIVEGATEWAYasaH.320/H.323gateway,whichisessentialforthesmoothtransition,CiscoIP/VA3510asaH.323/MCU,andCisco2610asagatekeeperwereinstalledatKEKinMarch2001,Andthetransitionstarted.Inthispaper,we'lldescribethecollaborativeenvironmentwhichouruserscanhave,togetherwithitsoperationalresults.

  • 标签: H.323 高能物理 核物理 实验
  • 简介:Thedefectchangesin6H-SiCafterannealingand10MeVelectronirradiationhavebeenstudiedbyusingavariable-energypositronbeam.Itwasfoundthatafterannealing,thedefectconcentrationinn-type6H-SiCdecreasedduetorecombinationwithinterstitials.Whenthesamplewasannealedat1400℃for30mininvacuum,a20-nmthicknessSilayerwasfoundonthetopoftheSiCsubstrate,thisisadirectproofoftheSiatomsdiffusingtosurfacewhenannealedathightemperaturestages.After10MeVelectronirradiation,forn-type6H-SiC,theSparameterincreasedfrom0.4739to0.4822,andtherelativepositron-trappingratewasabout27.878timesoftheoriginsample,thisshowsthattherearesomedefectscreatedinn-type6H-SiC.Forp-type6H-SiC,itisveryunclear,thismaybebecauseoftheoppositechargeofvacancydefects.

  • 标签: 正电子束 6H-SIC 碳化硅 退火 半导体材料 空缺
  • 简介:LinuxbasednetworkedPCsclustersarereplacingboththeVMEnonuniformdirectmemoryaccesssystemsandSMPsharedmemorysystemsusedpreviouslyfortheonlineeventfilteringandreconstrucion.ToallowanoptimaluseofthedistributedresourcesofPCclustersanopensoftwareframeworkispresentlybeingdevelopedbasedonadataflowparadigmforeventprocessing.Thisframeworkallowsforthedistributionofthedataofphysicseventsandassociatedcalibrationdatatomultiplecomputersfrommultipleinputsourcesforprocessingandthesubsequentcollectionoftheprocessedeventsatmultipleoutputs.Thebasisofthesystemistheeventrepository,basicallyafirst-infirst-outeventstorewhichmaybereadandwritteninamannersimilartosequentialfileaccess.Eventsarestoredinandtransferredbetweenrepositoriesassuitablylargesequencestoenablehighthroughput.Multiplereaderscanreadsimultaneouslyfromasinglerepositorytoreceiveeventsequencesandmultiplewriterscaninserteventsequencestoarepository,Hencerepositoriesareusedforeventdistributionandcollection.Tosupportsynchronisationoftheeventfolowtherepositoryimplementsbaaiers.Abarriermustbewrittenbyallthewritersofarepositorybeforeanyreadercanreadthebarrier,Areadermustreadabarrierbeforeitmayreceivedatafrombehindit.Onlyafterallreadershavereadthebarrieristhebarrieremovedfromtherepository.Abarriermayalsohaveattacheddata,Inthiswaycalibrationdatacanbedistributedtoallproessuingunits.Therepositoriesareimplementedasmulti-threadedCORBAobjectsinC++andCORMAisusedforalldatatransfers,JobsetupscriptsarewritteninpythonandinteractivestatusandhistogramdisplayisprovidedbyaJavaprogram.JobsrununderthePBSbatchsystemprovidingshareduseofresourcesforonlinetriggering,offlinemassreporcessinganduseranalysisjobs.

  • 标签: H1实验 数据流 数据处理