简介:Wediscusstheincompletesemi-iterativemethod(ISIM)foranapproximatesolutionofalinearfixedpointequationsx=Tx+cwithaboundedlinearoperatorTactingonacomplexBanachspaceXsuchthatitsresolventhasapoleoforderkatthepoint1.SufficientconditionsfortheconvergenceofISIMtoasolutionofx=Tx+c,wherecbelongstotherangespaceof(I-T)k,areestablished.WeshowthattheISIMhasanattractivefeaturethatitisusuallyconvergentevenwhenthespectralradiusoftheoperatorTisgreaterthan1andInd1T≥1.ApplicationsinfiniteMarkovchainisconsideredandillustrativeexamplesarereported,showingtheconvergencerateoftheISIMisveryhigh.
简介:Thepurposeofthepaperistoestablishatheoryoftheconstantheatfluxratioacrossthefrozenlayerbasedonthedimensionalanalysisofthesystemequationsdescribingthefreezingprocesses.Ananalyticalmodelisthendeveloped,utilizingthistheory,forsolvingtheplanar,cylindricalandsphericalfreezingproblemswithbothinwardandoutwardfreezing.Asthereisnoexactsolutionavailableforthecylindricalandsphericalfreezingprocesses,thetemperaturedistributionintheplanarsolidificationobtainedfromthemodeliscomparedwiththeexactsolution.Theyareinexcellentagreement.Forthecylindricalandsphericalfreezing,thecompleteinwardsolidificationtimescalculatedbythemodelarecomparedwiththoseobtainedfromreferences.Theresultsareingoodagreement.Thegreatadvantageoftheproposedmodelisitssimplicityandissufficientlyaccurateformostpracticalapplications
简介:在这篇论文,为解决单个延期的二拍子的圆舞连续性Runge-Kutta(TSCRK)方法的一个班微分方程(DDE)被介绍。方法被给的这的数字稳定性的分析。我们考虑二个不同盒子:(ⅰ)τ≥h,(ⅱ)τ
简介:Aself-adaptiveprecisealgorithminthetimedomainwasemployedtosolve2-Dnonlinearcoupledheatandmoisturetransferproblems.Byexpandingvariablesatadiscretizedtimeinterval,thevariationsofvariablescanbedescribedmoreprecisely,andanonlinearcoupledinitialandboundaryvalueproblemwasconvertedintoaseriesofrecurrentlinearboundaryvalueproblemswhicharesolvedbyFEtechnique.Inthecomputation,noadditionalassumptionandthenonlineariterationarerequired,andacriterionforself-adaptivecomputationisproposedtomaintainsufficientcomputingaccuracyforthechangesizesoftimesteps.Inthenumericalcomparison,thevariationsofmaterialpropertieswithtemperature,moisturecontent,andbothtemperatureandmoisturecontentaretakenintoaccount,respectively.Satisfactoryresultshavebeenobtained,indicatingthattheproposedapproachiscapableofdealingwithcomplexnonlinearproblems.
简介:Basedontheextendedhomogeneouscapacityhighprecisionintegrationmethodandthespectrummethodofvirtualboundarywithacomplexradiusvector,anovelsemi-analyticalmethod,whichhassatisfactorycomputationeffectivenessandprecision,ispresentedforsolvingtheacousticradiationfromasubmergedinfinitenon-circularcylindricalshellstiffenedbylongitudinalribsbymeansoftheFourierintegraltransformationandstationaryphasemethod.Inthiswork,besidesthenormalinteractingforce,whichiscommonlyadoptedbysomeresearchers,theotherinteractingforcesandmomentsbetweenthelongitudinalribsandthenon-circularcylindricalshellareconsideredatthesametime.Theeffectsofthenumberandthesizeofthecross-sectionoflongitudinalribsonthecharacteristicsofacousticradiationareinvestigated.NumericalresultsshowthatthemethodproposedismoreefficientthantheexistingmixedFE-BEmethod.
简介:Fastsolvinglarge-scalelinearequationsinthefiniteelementanalysisisaclassicalsubjectincomputationalmechanics.Itisakeytechniqueincomputeraidedengineering(CAE)andcomputeraidedmanufacturing(CAM).Thispaperpresentsahigh-efciencyimprovedsymmetricsuccessiveover-relaxation(ISSOR)preconditionedconjugategradient(PCG)method,whichmaintainstheconvergenceandinherentparallelismconsistentwiththeoriginalform.Ideally,thecomputationcanbereducednearlyby50%ascomparedwiththeoriginalalgorithm.Itissuitableforhigh-performancecomputingwithitsinherentbasichigh-efciencyoperations.Bycomparingwiththenumericalresults,itisshownthattheproposedmethodhasthebestperformance.
简介:Heattransportatthemicroscaleisofvitalimportanceinmicrotechnologyapplications.Theheattransportequationisdifferentfromthetraditionalheattransportequationsinceasecondorderderivativeoftemperaturewithrespecttotimeandathird-ordermixedderivativeoftemperaturewithrespecttospaceandtimeareintroduced.Inthisstudy,wedevelopahybridfiniteelement-finitedifference(FE-FD)schemewithtwolevelsintimeforthethreedimensionalheattransportequationinacylindricalthinfilmwithsubmicroscalethickness.Itisshownthattheschemeisunconditionallystable.Theschemeisthenemployedtoobtainthetemperatureriseinasub-microscalecylindricalgoldfilm.Themethodcanbeappliedtoobtainthetemperatureriseinanythinfilmswithsub-microscalethickness,wherethegeometryintheplanardirectionisarbitrary.