简介:LetXt(x)bethesolutionofstochasticdierentialequationswithsmoothandboundedderivativescoeffcients.LetXnt(x)betheEulerdiscretizationschemeofSDEswithstep2-n.Inthisnote,weprovethatforanyR>0andγ∈(0,1/2),supt∈[0,1],|x|≤R|Xnt(x,ω)-Xt(x,ω)|≤ξR,γ(ω)2-nγ,n≥1,q.e.,whereξR,γ(ω)isquasi-everywherefinite.
简介:COMPLETECONVERGENCEOFERRORVARIANCEESITIMATESUNDER¢-MIXINGERRORINLINEARMODELSXueLiugen(薛留根)(XuchangTeachersCollege,Henan461000...
简介:Afewweakandstrongconvergencetheoremsofthemodifiedthree-stepiterativesequencewitherrorsandthemodifiedIshikawaiterativesequencewitherrorsforasymptoticallynon-expansivemappingsinanynon-emptyclosedconvexsubsetsofuniformlyconvexBanachspacesareestablished.TheresultspresentedinthispapersubstantiallyextendtheresultsduetoChang(2001),Osilikeandhniagbosor(2000),Rhoades(1994)andSchu(1991).
简介:Amorerelaxedsufficientconditionfortheconvergenceoffiltered-XLMS(FXLMS)algorithmispresented.Itispointedoutthatifsomepositiverealconditionforsecondarypathtransferfunctionanditsestimatesissatisfiedwithinallthefrequencybands,FXLMSalgorithmconvergeswhateverthereferencesignalislike.Butiftheabovepositiverealconditionissatisfiedonlywithinsomefrequencybands,theconvergenceofFXLMSalgorithmisdependentonthedistributionofpowerspectraldensityofthereferencesignal,andtheconvergencestepsizeisdeterminedbythedistributionofsomespecificcorrelationmatrixeigenvalues.ApplyingtheconclusionabovetotheDelayedLMS(DLMS)algorithm,itisshownthatDLMSalgorithmwithsomeerroroftimedelayestimationconvergesincertaindiscretefrequencybands,andthewidthofwhicharedeterminedonlybythe"time-delayestimationerrorfrequency"whichisequaltoonefourthoftheinverseofestimatederrorofthetimedelay.
简介:TheInternetevolvestoincorporatevery-high-bandwidthopticallinksandmorelarge-delaysatellitelinks.TCPfacesnewchallengesinthisuniqueenvironment.TheoryandexperimentsshowedthatTCPbecomesinefficientandispronetobeunstableastheper-flowproductofbandwidthandlatencyincreases,regardlessofthequeuingscheme.Variable-structurecongestionControlProtocol(VCP)isproposedtoaddresstheseproblems.However,VCPhasproblemintermsofconvergencetime,i.e.,ittakesalongtimeforanewVCPflowtoachievefairbandwidthallocationiftheexistingVCPflowshavelargecon-gestionwindows.ThispaperproposedanExtendedVariable-structurecongestionControlProtocol(EVCP),whichadoptedaconvergencecontroller.Thebasicideaofconvergencecontrolleristhatifaflowhaslargerwindowthanitsfairwindow,itscongestionwindowshouldbedecreasedmoreaggressivelythanusualinMultiplicativeDecrease(MD)phase.SimulationsshowedthatEVCPhasbetterperformanceintermsofconvergencetimewhilekeepingtheadvantagesofVCP.
简介:ImplicitRunge-Kuttamethodishighlyaccurateandstableforstiffinitialvalueproblem.ButtheiterationtechniqueusedtosolveimplicitRunge-Kuttamethodrequireslotsofcomputationalefforts.Inthispaper,weextendtheParallelDiagonalIteratedRungeKutta(PDIRK)methodstodelaydifferentialequations(DDEs).WegivetheconvergenceregionofPDIRKmethods,andanalyzethespeedofconvergenceinthreepartsfortheP-stabilityregionoftheRunge-Kuttacorrectormethod.Finally,weanalysisthespeed-upfactorthroughanumericalexperiment.TheresultsshowthatthePDIRKmethodstoDDEsareefficient.
简介:调查一个明确的迎风的有限元素方法的集中,平均边的有限元素方法到多维的分级的能量守恒定律。有限元素计划和主要集中定理的讨论;技术词根的证明。
简介:Inthispaper,wefirstprovideageneralizeddifferencemethodforthe2-dimensionalNavier-Stokesequationsbycombingtheideasofstaggeredscheme[6]mandgeneralizedupwindscheme[4]inspace,andbybackwardEulertime-stepping.Thenweapplytheabstractframeworkof[7]toproveitslong-timeconvergence.Finally,anumericalexampleforsolvingdrivencavityflowsisgiven.
简介:Weproposeanovelnumericalapproachfordelaydifferentialequationswithvanishingproportionaldelaysbasedonspectralmethods.ALegendre-collocationmethodisem-ployedtoobtainhighlyaccuratenumericalapproximationstotheexactsolution.Itisprovedtheoreticallyanddemonstratednumericallythattheproposedmethodconvergesexponentiallyprovidedthatthedatainthegivenpantographdelaydifferentialequationaresmooth.