简介:ThispaperintroducesthedefinitionoftheOrthogonalTypeNodeConfigurationanddiscussesthecorrespondingmultivariateLagrange,HermiteandBirkhoffinterpolationproblemsinhighdimensionalspaceRs(s>2).ThisnodeconfigurationcanbeconsideredtobeakindofextensionoftheCrossTypeNodeConfiguration[1],[2]inR2tohighdimensionalspaces.AndtheMixedTypeNodeConfigurationinRs(s>2)isalsodiscussedinthispaperinanexample.
简介:Mathergavethenecessaryandsufficientconditionsforthefinitedeterminacys-moothfunctiongermswithnomorethancodimension4.Thetheoremisveryeffectiveondetermininglowcodimensionsmoothfunctiongerms.Inthispaper,theconceptofrightequivalentforsmoothfunctiongermsringgeneratedbytwoidealsfinitelyisdefined.Thecontainmentrelationshipsoffunctiongermsstillsatisfyfinitek-determinacyundersufficientlysmalldisturbancewhicharediscussedinorbittangentspaces.Furthermore,themethodsinjudgingtherightequivalencyofArnoldfunctionfamilywithcodimension5arepresented.
简介:Split-stepPadémethodandsplit-stepfouriermethodareappliedtothehigher-ordernonlinearSchrdingerequation.ItisprovedthatacombinationofPadéschemeandspectralmethodisthemosteffectivemethod,whichhasaspectral-likeresolutionandgoodstabilitynature.Inparticular,weproposeanunconditionalstableimplicitPadéschemetosolveoddordernonlinearequations.NumericalresultsdemonstratetheexcellentperformanceofPadéschemesforhighordernonlinearequations.
简介:AbstractInthispaperwestudysomenonoverlappingdomaindecompositionmethodsforsolvingaclassofellipticproblemsarisingfromcompositematerialsandflowsinporousmediawhichcontainmanyspatialscales.Ourpreconditionerdiffersfromtraditionaldomaindecompositionpreconditionersbyusingacoarsesolverwhichisadaptivetosmallscaleheterogeneousfeatures.Whiletheconvergencerateoftraditionaldomaindecompositionalgorithmsusingcoarsesolversbasedonlinearorpolynomialinterpolationsmaydeteriorateinthepresenceofrapidsmallscaleoscillationsorhighaspectratios,ourpreconditionerisapplicabletomultiple-scaleproblemswithoutrestrictiveassumptionsandseemstohaveaconvergenceratenearlyindependentoftheaspectratiowithinthesubstructures.ArigorousconvergenceanalysisbasedontheSchwarzframeworkiscarriedout,andwedemonstratetheefficiencyandrobustnessoftheproposedpreconditionerthroughnumericalexperimentswhichincludeproblemswithmultipl
简介:
简介:Inthispaper,analmostP-stabletwo-stepsixth-orderHybridmethodwithphase-lagoforderinfinityandaclassexpliciteighth-orderObreckoffmethodswithphase-lagoforder10-24aredevelopedforthenumericalintegrationofthespecialsecond-orderperiodicinitial-valueproblems.Thesemethodshavetheadvantageofhigheralgebraicorderandconsiderablysmallerphase-tagcomparedwithsomemethodsin[1-6].Numericalexamplesindicatethatthesenewmethodsaremoreaccuratethanmethodsdevelopedby[1-6].
简介:Thispaperintroducestheuseofpartitionofunitymethodforthedevelopmentofahighorderfinitevolumediscretizationschemeonunstructuredgridsforsolvingdiffusionmodelsbasedonpartialdifferentialequations.Theunknownfunctionanditsgradientcanbeaccuratelyreconstructedusinghighorderoptimalrecoverybasedonradialbasisfunctions.Themethodologyproposedisappliedtothenoiseremovalprobleminfunctionalsurfacesandimages.Numericalresultsdemonstratetheeffectivenessofthenewnumericalapproachandprovideexperimentalorderofconvergence.
简介:Westudypreconditioningtechniquesusedinconjunctionwiththeconjugategradientmethodforsolvingmulti-length-scalesymmetricpositivedefinitelinearsystemsoriginatingfromthequantumMonteCarlosimulationofelectroninteractionofcorrelatedmaterials.Existingpreconditioningtechniquesarenotdesignedtobeadaptivetovaryingnumericalpropertiesofthemulti-length-scalesystems.Inthispaper,weproposeahybridincompleteCholesky(HIC)preconditioneranddemonstrateitsadaptivitytothemulti-length-scalesystems.Inaddition,weproposeanextensionofthecompressedsparsecolumnwithrowaccess(CSCR)sparsematrixstorageformattoefficientlyaccommodatethedataaccesspatterntocomputetheHICpreconditioner.Weshowthatformoderatelycorrelatedmaterials,theHICpreconditionerachievestheoptimallinearscalingofthesimulation.Thedevelopmentofalinear-scalingpreconditionerforstronglycorrelatedmaterialsremainsanopentopic.
简介:Inthispaper,ahighaccuracyfinitevolumeelementmethodispresentedfortwo-pointboundaryvalueproblemofsecondorderordinarydifferentialequation,whichdiffersfromthehighordergeneralizeddifferencemethods.Itisprovedthatthemethodhasoptimalorderer-rorestimateO(h3)inH1norm.Finally,twoexamplesshowthatthemethodiseffective.
简介:Ahigh-orderleap-frogbasednon-dissipativediscontinuousGalerkintime-domainmethodforsolvingMaxwell'sequationsisintroducedandanalyzed.Theproposedmethodcombinesacenteredapproximationfortheevaluationoffluxesattheinterfacebetweenneighboringelements,withaNth-orderleap-frogtimescheme.Moreover,theinterpolationdegreeisdefinedattheelementlevelandthemeshisrefinedlocallyinanon-conformingwayresultinginarbitrarylevelhangingnodes.ThemethodisprovedtobestableundersomeCFL-likeconditiononthetimestep.Theconvergenceofthesemi-discreteapproximationtoMaxwell'sequationsisestablishedrigorouslyandboundsontheglobaldivergenceerrorareprovided.Numericalexperimentswithhigh-orderelementsshowthepotentialofthemethod.