简介:在这篇文章,我们得到non-selfsimilar基本在另一种看法能量守恒定律飘动,它与平常的自我类似的转变不同。答案有不同全球结构。这篇文章被划分成三部分。第一部分是介绍。在第二部分,我们讨论non-selfsimilar基本波浪和他们二维的能量守恒定律的一个班的相互作用。在这种情况中,我们考虑起始的断绝是有u+的抛物线的盒子>0,当明确的non-selfsimilar变成稀薄波浪能被获得时。在第二部分,我们考虑盒子u+的答案结构<0。新答案结构被在不同基本波浪之间的相互作用获得,并且将继续与另外的状态交往。全球答案将与一种尺寸的状况很不同。
简介:Inthispaperwedescribeamulti-gridalgorithmformixedproblemswithpenaltybythelinearfiniteelementapproximation.Itisprovedthattheconvergencerateofthealgorithmisboundedawayfrom1independentlyofthemeshsize.Forconvenience,weonlydiscussJacobirelaxationassmoothingoperatorindetail.
简介:Inthispaper,wepresentm-timesecant-likemulti-projectionalgorithmforsparseunconstrainedminimizationproblem.Weprovethismethodareallq-superlinearlyconvergenttothesolutionaboutm≥l.Atlast,wediscussfromsomenumericalresults,howtochoosethenumbermtodeterminetheapproximatingmatrixproperlyinpracticaluse.
简介:Westudypreconditioningtechniquesusedinconjunctionwiththeconjugategradientmethodforsolvingmulti-length-scalesymmetricpositivedefinitelinearsystemsoriginatingfromthequantumMonteCarlosimulationofelectroninteractionofcorrelatedmaterials.Existingpreconditioningtechniquesarenotdesignedtobeadaptivetovaryingnumericalpropertiesofthemulti-length-scalesystems.Inthispaper,weproposeahybridincompleteCholesky(HIC)preconditioneranddemonstrateitsadaptivitytothemulti-length-scalesystems.Inaddition,weproposeanextensionofthecompressedsparsecolumnwithrowaccess(CSCR)sparsematrixstorageformattoefficientlyaccommodatethedataaccesspatterntocomputetheHICpreconditioner.Weshowthatformoderatelycorrelatedmaterials,theHICpreconditionerachievestheoptimallinearscalingofthesimulation.Thedevelopmentofalinear-scalingpreconditionerforstronglycorrelatedmaterialsremainsanopentopic.
简介:TheembeddedboundarymethodforsolvingellipticandparabolicproblemsingeometricallycomplexdomainsusingCartesianmeshesbyJohansenandColella(1998,J.Comput.Phys.147,60)hasbeenextendedforellipticandparabolicproblemswithinteriorboundariesorinterfacesofdiscontinuitiesofmaterialpropertiesorsolutions.Secondorderaccuracyisachievedinspaceandtimeforbothstationaryandmovinginterfaceproblems.Themethodisconservativeforellipticandparabolicproblemswithfixedinterfaces.Basedonthismethod,afronttrackingalgorithmfortheStefanproblemhasbeendeveloped.Theaccuracyofthemethodismeasuredthroughcomparisonwithexactsolutiontoatwo-dimensionalStefanproblem.Thealgorithmhasbeenusedforthestudyofmeltingandsolidificationproblems.
简介:Inthisarticle,weestablishtheglobalstabilityofanendemicequilibriumofmulti-groupSIRepidemicmodels,whichhavenotonlyanexchangeofindividualsbetweenpatchesthroughmigrationbutalsocrosspatchinfectionbetweendifferentgroups.Asaresult,wepartiallygeneralizetherecentresultinthearticle[16].
简介:在这篇论文,我们与p拉普拉斯算符操作员获得积极答案到下列multi-pointsingular边界值问题p=|s|p-2s,p≥2;ξi∈?(0,1)(i=1,2,···,n),0≤αi,βi<1(i=1,2,···,n),并且q(t)可能在t=是单个的0,1;f(t,u,u′)可能在u′=是单个的0。
简介:Anadaptivemulti-scaleconjugategradientmethodfordistributedparameterestimations(orinverseproblems)ofwaveequationispresented.Theidentificationofthecoefficientsofwaveequationsintwodimensionsisconsidered.First,theconjugategradientmethodforoptimizationisadoptedtosolvetheinverseproblems.Second,theideaofmulti-scaleinversionandthenecessaryconditionsthattheoptimalsolutionshouldbethefixedpointofmulti-scaleinversionmethodisconsidered.Anadaptivemulti-scaleinversionmethodfortheinverseproblemisdevelopedinconjunctionwiththeconjugategradientmethod.Finally,somenumericalresultsareshowntoindicatetherobustnessandeffectivenessofourmethod.
简介:这份报纸是一个continue工作[4,5]。在以前的二份报纸,我们与看情况时间的抑制术语学习了多维的可压缩的Euler方程的Cauchy问题--(1+t)u,在此0并且>0是常数。我们显示出那,为所有0并且>0,Cauchy问题的光滑的答案全球性存在或在有限时间骤起。在现在的纸,而不是Cauchy问题,我们在一半考虑起始边界的价值问题空间有空间尺寸d=的d+2,3。在方程和液体涡度的特殊结构的帮助下,我们克服困难从边界效果产生。我们证明那在那里存在0的一个全球光滑的解决方案<1当起始的数据接近它的平衡状态时。另外,液体涡度的指数的腐烂将也被建立。
简介:Thenumericalsolutionoflargescalemulti-dimensionalconvectiondiffusionequationsoftenrequiresefficientparallelalgorithms.Inthiswork,weconsidertheextensionofarecentlyproposednon-overlappingdomaindecompositionmethodfortwodimensionaltimedependentconvectiondiffusionequationswithvariablecoefficients.Bycombiningpredictor-correctortechnique,modifiedupwinddifferenceswithexplicitimplicitcoupling,themethodunderconsiderationprovidesintrinsicparallelismwhilemaintaininggoodstabilityandaccuracy.Moreover,formulti-dimensionalproblems,themethodcanbereadilyimplementedonamulti-processorsystemanddoesnothavethelimitationonthechoiceofsubdomainsrequiredbysomeothersimilarpredictor-correctororstabilizedschemes.Thesepropertiesofthemethodaredemonstratedinthisworkthroughbothrigorousmathematicalanalysisandnumericalexperiments.