学科分类
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53 个结果
  • 简介:Thenecessitytodistributethedataoverthewideareanetwork(WAN)tothephysicists'homeinstituteswillincrease,andtheeffectiveutilizationofthenetworkbecomescrucial,However,networksinthefutureWANwilltypicallyhavealargebandwidthatanorderofgigabitpersecond,withalatencyofseveralhundredssecondssothatthelargebandwidth-delayprodeuctextendstotensofmegabytesandnumerousproblemsareencountered.suchnetworksarecalled"longfatnetworks(LFNs)"Inordertostudythedatatransferoperatingonalongfatnetwork,wehavebuiltthePCclustersconnectedwiththerouterwhichcansimulatebandwidthlimitations.delays,packetlosses,andmultipatheffects.thisrouterisrunningonFreeBSDwithDUMMYNETkerneloption.Onthesemachineswehavemeasuredtheperformanceofthebulkdatatransfterwithnumerousconditionsandstudiedtheeffecienttransftermethods.

  • 标签: 广域网 数据传输 PC FARM
  • 简介:Inthispaper,westudytheasymptoticCUSUMtestsfordetectingchangesinthemeanorvarianceofamoving-averageprocesswithlongmemory.Whenthereisnochangeover[O,T],theasymptoticdistributionoftheteststatisticisderived,whichallowsustofindasymptoticcriticalvalues.Whenthereisachange,thebehavioroftheteststatisticisdiscussed.Conditionsfortheconsistencyofthesetestsarealsodiscussed.Basedontheasymptoticresults,simulationstudiesoftestingforchangesinthemeanshowthattheCUSUMtestproposedperformswell.

  • 标签: 测试过程 移动平均 记忆 检验统计量 一致性条件 方差检验
  • 简介:Inthispaper,twofinitedifferenceschemesarepresentedforinitial-boundaryvalueproblemsofRegularizedLong-Wave(RLW)equation.Theyallhavetheadvantagesthattherearediscreteenergieswhichareconserved.ConvergenceandstabilityofdifferencesolutionswithorderO(h2+τ2)areprovedintheenergynorm.Numericalexperimentresultsdemonstratetheeffectivenessoftheproposedschemes.

  • 标签: RLW方程 微分概形 守恒 收敛
  • 简介:Bisphenolscontaininglongaliphatichydrocarbonsidechainsweresynthesizedbythecondensationofphenolwithaldehydeorketoneinthepresenceofheteropolyacid.TheirstructureswerecharacterizedbyIR,1HNMR,13CNMRandelementanalysis.Theexperimentresultsshowthatwhenheteropolyacidwasusedasacatalyst,thesebisphenolswereobtainedinhighselectivityandhighyields.

  • 标签: 合成 双酚A 碳氢化合物侧链 杂多酸 结构表征 催化剂
  • 简介:ThelongtermaccessibilityofitsdataisanimportantconcernoftheDELPHIcollaboration.Itisourassumptionthatthestorageofthedataitselfwillbeaminorissueduetotheprogressinstoragetechnologies.ThereforeDELPHIfocusesonareorganisationofthedata,whichshouldprovideaflexibleandcoherentframeworkforphysicsanalysisinthefuture.ThispaperdescribesthecurrentstatusoftheIDEA(ImprovedDElphiAnalysis)projectwhichwillensureusabilityofDELPHIdataforfuturegenerationsofphysicists.

  • 标签: 高能物理实验 DELPHI数据 IDEA项目
  • 简介:<正>Supposethat{αk}k∞=-∞isaLacunarysequenceofpositivenumberssatisfyinginfαk+1/αk=α>1andthatΩ(y’)isafunctionintheBesovspaceB10,1(Sn-1)whereSn-1istheunitsphereonRn(n≥2).Weprovethatif∫Sn-1Ω(y’)dσ(y’)=0thenthediscretesingularintegraloperatorTΩf(x)=∫(Sn-1)f(x-αky’)Ω(y’)dσ(y’)andtheassociatedmaximaloperatorTΩf(x)=∫Sn-1f(x-αky’)Ω(y’)dσ(y’)arebothboundedinthespaceL2(Rn).ThetheoremsinthispaperimprovearesultbyDuoandikoetxeaandRubiodeFranciaintheL2case.

  • 标签: SINGULAR integral BESOV space ROUGH KERNEL
  • 简介:Thispaperpresentsameshlessmethodforthenonlineargeneralizedregularizedlongwave(GRLW)equationbasedonthemovingleast-squaresapproximation.ThenonlineardiscreteschemeoftheGRLWequationisobtainedandissolvedusingtheiterationmethod.Atheoremontheconvergenceoftheiterativeprocessispresentedandprovedusingtheoremsoftheinfinitynorm.Comparedwithnumericalmethodsbasedonmesh,themeshlessmethodfortheGRLWequationonlyrequiresthescatterednodesinsteadofmeshingthedomainoftheproblem.Someexamples,suchasthepropagationofsinglesolitonandtheinteractionoftwosolitarywaves,aregiventoshowtheeffectivenessofthemeshlessmethod.

  • 标签: 正则长波方程 非线性方程 无网格法 广义 收敛性定理 无网格方法
  • 简介:Longpilesoftheoceanoilplatformareusuallymanufacturedastheintegrationofseveralsegments,whichhavetobeassembledonebyoneduringinstallation.Duringpiledriving,excessiveporepressurewillbuildupinsuchahighlevelthathydraulicfracturinginthesoilroundthepilemaytakeplace,whichwillcausethesoiltoconsolidatemuchfasterduringpileextensionperiod.Consequently,afterpileextension,thesoilstrengthwillrecovertosomeextentandthedrivingresistancewillincreaseconsiderably,whichmakesrestartingdrivingthepileverydifficultandevencausesrefusal.Afiniteelement(FE)analysisprocedureispresentedforjudgingtheriskofrefusalbyestimatingtheblowcountsafterpileextension,inwhichtheregainofsoilstrengthisconsidered.AcaseanalysisinBohaiGulfisperformedusingtheproposedproceduretoexplainthepilerefusalphenomenon.

  • 标签: 超长桩 渤海湾 驾驶 海洋石油平台 水力压裂 土壤强度
  • 简介:Amethodforinertialconfinementfusiondrivenbypowerfullongwavelengthelectromagneticpulses(EMPs),suchasCO2laserpulsesorhighpowermicrowavepulses,isproposed.Duetothehighefficiencyofgeneratingsuchlongwavelengthelectromagneticpulses,thismethodisespeciallyimportantforthefuturefusionelectricitypower.Specialfueltargetsaredesignedtoovercometheshortcomingsofthelongwavelengthelectromagneticpulses.

  • 标签: CO2laser INERTIAL CONFINEMENT FUSION LASER ACCELERATION
  • 简介:Basedonanewdefinitionofnonlocalvariable,thispaperestablishestheLagrangianformulationforcontinuumwithinternallong-rangeinteractions.Distinguishedfromtheexistingtheories,thenonlocaltermintheLagrangianformulationautomaticallysatisfiesthezeromeanconditiondeterminedbytheactionandreactionlaw.Bythisformulation,elasticwaveinarodwiththeinternallong-rangeinteractionsisinvestigated.Thedispersionoftheelasticwaveispredicted.

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  • 简介:Usingultrasonicguidedwavestoassesslongbonefracturesandfracturehealinghasbecomeapromisingdiagnosticissue.Butthemultimodeoverlapoftheguidedwaveschallengesthequantitativeevaluationandclinicalapplication.Inthepreformedstudy,inordertosimplifythesignalinterpretation,thelow-frequencysinusoidialsignalswereusedtoonlyexciteS0andA0modesinfracturedlongbones.TheamplitudesofS0andA0modeswerenumericallyanalyzedwithvariationincrackwidthandfractureangle.Numericalsimulation,basedonthetwo-dimensionfinite-differencetime-domain(2D-FDTD)revealsthatbothS0andA0amplitudesdecreasewiththefracturewidening.However,theincreaseinfractureanglegraduallyenhancestheA0amplitude,whilewithrespecttotheS0mode,itsamplitudeshowsanon-monotonictrendtothevariationinfractureanglewithaturningpointaround45°.TheamplituderatiobetweenS0andA0canreflectthevariationsincrackwidthandfractureangles.ThesimulationillustratesthatultrasonicguidedS0andA0modesaresensitivetothedegreeofbothverticalandobliquefracturesinthelongcorticalbone.Thesefindingsmaybehelpfulforfracturesdiagnosisandhealingevaluationofthelongbone.

  • 标签: 骨折愈合 长骨骨折 超声导波 裂缝宽度 低阶 振幅变化
  • 简介:ForagraphG,wedenotebyp(G)andc(G)thenumberofverticesofalongestpathandalongestcycleinG,respectively.ForavertexvinG,id(v)denotestheimplicitdegreeofv.Inthispaper,weobtainthatifGisa2-connectedgraphonnverticessuchthattheimplicitdegreesumofanythreeindependentverticesisatleastn+1,theneitherGcontainsahamiltonianpath,orc(G)≥p(G)-1.

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  • 简介:Aso-called“localprobabilisticParisrelationmethod”waspresentedformeasuringtherandomthresholdsoflongfatiguecrackpropagation.Acheckwasmadetotheconventionalmethod,inwhichthethresholdsweremeasuredstatisticallyanddirectlybythetestdata.Itwasrevealedthatthismethodwasnotreasonablebecausethetestdatahaveseldomaunifiedlevelofcrackgrowthrates.Differently,inthepresentedmethodtheParis-Erdoganequationwasappliedtomodelthelocaltestdataaroundthethresholds.Localprobabilisticrelationswithboththesurvivalprobabilityandtheconfidencewereestablishedonalognormaldistributionofthestressdensityfactors.Andthen,theprobabilisticthresholdswerederivedfromtheprobabilisticfactorswithagivencriticallevelofgrowthrate.AnanalysisonthetestdataofLZ50axlesteelfortheChineserailwayvehiclesverifiesthatthepresentmethodisfeasibleandavailable.

  • 标签: 疲劳裂缝 随机极限 局部概率 LZ50钢
  • 简介:LongtimebehaviorofdegenerateequationswiththenonlinearityofpolynomialgrowthofarbitraryorderonthewholespaceRNisconsidered.Byusing-trajectoriesmethods,weprovedthatweaksolutionsgeneratedbydegenerateequationspossessan(L2U(RN),L2loc(RN))-globalattractor.Moreover,theupperboundsoftheKolmogorovε-entropyforsuchglobalattractorarealsoobtained.

  • 标签: 退化抛物方程 研发 柯尔莫哥洛夫 退化方程 全局吸引 非线性
  • 简介:LetMfbetheKakeyamaximalfunctionind-dimensionalEuclideanspace,withsamebaseconsistingofcylindersofeccentricityN.Theinequalityshoumforabasesatisfyingadirectioncondition,where?andcareconstantsdependingonlyond.

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  • 简介:Inthiswork,westudythephotonicbandofcumulativeFibonaccilattices,ofwhichthestructureiscomposedofallgeneratedunitsinaFibonaccisequence.TheresultsarecomparedwithdistributedBraggreflector(DBR)structureswiththesamenumbersoflayers.Photonicbandgapsarefoundattwocharacteristicfrequencies,symmetricallyseparatedfromthecentralbandgapintheDBRcounterpart.FieldamplitudeandphasedistributionintheFibonaccilatticeindicatesaninterferentialoriginofthebandgaps.Fouriertransformontherefractiveindexprofileiscarriedout,andtheresultconfirmsadeterminatelong-rangeperiodicitythatagreeswellwiththephotonicbandstructure.

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  • 简介:Thispaperreportsthesynthesisofaseriesofpolysiloxanesbearinglongsidechainmeltedatlowtemperature.Thedrug(LNG)releasingpropertiesofthesiciconerubberfilmscontainingthesepolyorganosiloxaneswerestudied.Thereleaseratesofthedrugincreaseasthetemperatureriseupabovethemeltingtemperatureofthesepolyorganosiloxanes.

  • 标签: 合成 药物释放性 聚硅氧烷 侧链 支链
  • 简介:Thispaperanalysesthefiveyears'monitoredstrainscollectedfromalong-termhealthmonitoringsysteminstalledonabridgewithwavelettransform.Intheanalysis,themonitoredstrainsarepre-processed,featuresofthemonitoreddataaresummarizedbriefly.Theinfluencesofthebasefunctionsontheresultsofwaveletanalysisarestudiedsimultaneously.Theresultsshowthatthedbwaveletisagoodmotherwaveletfunctionintheanalysis,andtheorderNshouldbelargerthan20,butlessthan46indeco...

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