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61 个结果
  • 简介:Abstract.OgrobjectinthisartlcleistodescribetbeGalerklnschemeandnonlin-eaxGalerkinschemefortheapproximationofnonlinearevolutionequations,andtostudythestabilityoftheseschemes.SpatialdiscretizatloncanbepedormedbyeitherGalerklnspectralmethodornonlinearGalerldnspectralmethod;timediscretizatlortisdonehyEulersin.heinewklchisexplicitorimplicitinthenonlinearterms.Accordingtothestabilityanalysisoftheaboveschemes,thestabilityofnonllneexGalerklnmethodisbetterthanthatofGalexklnmethod.

  • 标签: 非线性发展方程 非线性GALERKIN方法 稳定性分析 偏微分方程 耗散型方程
  • 简介:IntroductionTheconceptsofInertialManifold(IM)[1]andApproximateInertialManifold(AIM)[2]fordissipativepartialdifferentialequati...

  • 标签: Navier_Stokes equations APPROXIMATE INERTIAL MANIFOLD non_singular
  • 简介:TheGalerkinandleast-squaresmethodsaretwoclassesofthemostpopularKrylovsubspacemethOdsforsolvinglargelinearsystemsofequations.Unfortunately,boththemethodsmaysufferfromseriousbreakdownsofthesametype:InabreakdownsituationtheGalerkinmethodisunabletocalculateanapproximatesolution,whiletheleast-squaresmethod,althoughdoesnotreallybreakdown,isunsucessfulinreducingthenormofitsresidual.Inthispaperwefrstestablishaunifiedtheoremwhichgivesarelationshipbetweenbreakdownsinthetwometh-ods.Wefurtherillustratetheoreticallyandexperimentallythatifthecoefficientmatrixofalienarsystemisofhighdefectivenesswiththeassociatedeigenvalueslessthan1,thentherestart-edGalerkinandleast-squaresmethodswillbeingreatrisksofcompletebreakdowns.Itappearsthatourfindingsmayhelptounderstandphenomenaobservedpracticallyandtoderivetreat-mentsforbreakdownsofthistype.

  • 标签: large linear systems iterative methods Krylov
  • 简介:Inthispaper,weareconcernedwithuniformsuperconvergenceofGalerkinmethodsforsingularlyperturbedreaction-diffusionproblemsbyusingtwoShishkin-typemeshes.Basedonanestimateoftheerrorbetweensplineinterpolationoftheexactsolutionanditsnumericalapproximation,aninterpolationpost-processingtechniqueisappliedtotheoriginalnumericalsolution.Thisresultsinapproximationexhibitsuperconvergencewhichisuniformintheweightedenergynorm.Numericalexamplesarepresentedtodemonstratetheeffectivenessoftheinterpolationpost-processingtechniqueandtoverifythetheoreticalresultsobtainedinthispaper.

  • 标签: GALERKIN方法 超收敛 奇摄动问题 伽辽金方法 后处理技术 反应扩散问题
  • 简介:Inthispaper,theminimaldissipationlocaldiscontinuousGalerkinmethodisstudiedtosolvetheellipticinterfaceproblemsintwo-dimensionaldomains.Theinterfacemaybearbitrarysmoothcurves.ItisshownthattheerrorestimatesinL2-normforthesolutionandthefluxareO(h2|logh|)andO(h|logh|^l/2),respectively.Innumericalexperiments,thesuccessivesubstitutioniterativemethodsareusedtosolvetheLDGschemes.Numericalresultsverifytheefficiencvandaccuracvofthemethod.

  • 标签: ELLIPTIC interface problem MINIMAL DISSIPATION local
  • 简介:AD(Alternatingdirection)Galerkinschemesford-dimensionalnonlinearpseudo-hyperbolicequationsarestudied.Byusingpatchapproximationtechnique,ADprocedureisrealized,andcalculation,workissimplified.ByusingGalerkinapproach,highlycomputationalaccuracyiskept.Byusingvariousprioriestimatetechniquesfordifferentialequations,difficultycomingformnon-linearityistreated,andoptimalH^1andL^2convergenceprop-ertiesaredemonstrated.Moreover,althoughalltheexistedADGalerkinschemesusingpatchapproximationarelimitedtohaveonlyoneorderaccuracyintimeincrement,yettheschemesformulatedinthispaperhavesecondorderaccuracyinit.ThisimpliesanessentialadvancementinADGalerkinaualysis.

  • 标签: 交替方向伽辽金格式 非线性伪双曲方程 AD 路径近似 优先估计 精确度
  • 简介:Akindofcalculatingmethodforhighorderdifferentialsexpandedbythewaveletscal-ingfunctionsandtheintegraloftheirproductusedinGalerkinFEMisproposed,sothatwecanusethewaveletGalerkinFEMtosolveboundary-valuedifferentialequationswithordershigherthantwo.TocombinethismethodwiththeGeneralizedGaussianintegralmethodinwavelettheory,wecanfindthatthismethodhasmanymeritsinsolvingmechanicalproblems,suchasthebendingofplatesandthosewithvariablethickness.Thenumericalresultsshowthatthismethodisaccurate.

  • 标签: APPLICATIONS of WAVELET theory SCALING functions
  • 简介:几个Galerkin-Petrov方法,包括的多项式搭配和分析元素的集中在Dirichlet空间的Toeplitz操作员的搭配方法,被建立。特别地,如果基础和测试功能拥有某些圆形的对称,如此的方法收敛,这被显示出。给词调音:GalerkinPetrov方法;多项式搭配;分析元素搭配;Toeplitz操作员;Dirichlet空间

  • 标签: 狄利克雷空间 TOEPLITZ算子 Galerkin-Petrov法 收敛
  • 简介:Weperformanalysisforafiniteelementsmethodappliedtothesingularself-adjointproblem.Thismethodusescontinuouspiecewisepolynomialspacesforthetrialandthetestspaces.WefitthetrialpolynomialspacebypiecewiseexponentialsandweapplysoexponentiallyfittedGalerkinmethodtosingularself-adjomtproblembyapproximatingdrivingtermsbyLagrangepiecewisepolynomials,linear,quadraticandcubic.Wtmeasuretheerroeinmaxnorm.Weshowthatmethodisoptimalofthefirstorderintheerrorestimate,WealsogivenumericalresultsfortheGalerkinapproximation.

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  • 简介:在这篇论文,我们在场一个不连续的Galerkin(DG)方法基于为解决在3-dimensional上从一个magnetohydrodynamics模型产生的一个第四顺序的卷屈方程的Nedelec有限元素空间围住Lipschitz多面体。我们证明方法为包含一个第四顺序的卷屈操作员的一个模型问题有最佳的错误估计。而且,在2种尺寸的一些数字结果被介绍验证理论结果。

  • 标签: 间断有限元 有限元方法 四阶 LIPSCHITZ 最优误差估计 有限元解
  • 简介:为Sobolev方程,我们在场一个新数字计划基于一个修改弱Galerkin有限元素方法,微分操作员被部分被弱形式通过平常的集成在接近。特别地,数字方法允许不连续的有限元素功能的使用和元素的任意的形状。在分离H1和L2标准的最佳的顺序错误估计为相应修改弱Galerkin有限元素答案被建立。最后,一些数字结果被给验证理论结果。[从作者抽象]

  • 标签: GALERKIN有限元法 SOBOLEV方程 索伯列夫方程 最优误差估计 间断有限元 微分算子
  • 简介:NonlinearGalerkinmethodsarenewschemesforintegratingdissipativesystems:Inthepresentpaper,weobtaintheestimatestotherateofconvergenceofsuchmethodsforKuramoto-Sivashinskyequations.Inparticular,byanillustrativeexample,weshowthatnonlinearGalerkinmethodsconvergefasterthantheusualGalerkinmethod.

  • 标签: Nonlinear GALERKIN methods APPROXIMATE INERTIAL MANIFOLDS
  • 简介:Designofenergeticmaterialsisanexcitingareainmechanicsandmaterialsscience.Energeticcompositematerialsareusedaspropellants,explosives,andfuelcellcomponents.Energyreleaseinthesematerialsareaccompaniedbyextremeevents:shockwavestravelattypicalspeedsofseveralthousandmeterspersecondandthepeakpressurescanreachhundredsofgigapascals.Inthispaper,wedevelopareactivedynamicscodeformodelingdetonationwavefeaturesinonesuchmaterial.Thekeycontributioninthispaperisanintegratedalgorithmtoincorporateequationsofstate,Arrheniuskinetics,andmixingrulesforparticledetonationinaTaylor–Galerkinfiniteelementsimulation.Weshowthattheschemecapturesthedistinctfeaturesofdetonationwaves,andthedetonationvelocitycompareswellwithexperimentsreportedinliterature.

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  • 简介:在这篇文章,我们为当模特儿的海军司烧方程的数字答案讨论一个新完整的分离计划粘滞不可压缩的流动。这个计划用混合有限元素和曲柄由非线性的Galerkin方法组成--Nicolson方法。下次,我们提供相应于这个计划的数字答案的秒顺序集中精确性。与平常的Galerkin计划相比,这个计划能在一样的集中精确性下面节省大量计算时间。(作者摘要)8个裁判员。

  • 标签: NONLINEAR GALERKIN METHOD CRANK-NICOLSON METHOD VISCOUS
  • 简介:Inthispaper,aunifiedmodelfortime-dependentMaxwellequationsindispersivemediaisconsidered.Thespace-timeDGmethoddevelopedin[29]isappliedtosolvetheunderlyingproblem.UnconditionalL2-stabilityanderrorestimateoforderOτr+1+hk+1/2areobtainedwhenpolynomialsofdegreeatmostrandkareusedforthetemporaldiscretizationandspatialdiscretizationrespectively.2-Dand3-Dnumericalexamplesaregiventovalidatethetheoreticalresults.Moreover,numericalresultsshowanultra-convergenceoforder2r+1intemporalvariablet.

  • 标签: 麦克斯韦方程组 有限元方法 色散媒质 时空 间断 数值结果
  • 简介:ThispaperproposesageometricallynonlineartotalLagrangianGalerkinmeshfreeformulationbasedonthestabilizedconformingnodalintegrationforefficientanalysisofsheardeformablebeam.Thepresentnonlinearanalysisencompassesthefullygeometricnonlinearitiesduetolargedeflection,largedeformationaswellasfiniterotation.Theincrementalequilibriumequationisobtainedbytheconsistentlinearizationofthenonlinearvariationalequation.TheLagrangianmeshfreeshapefunctionisutilizedt...

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