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258 个结果
  • 简介:StabilizedorChebyshevexplicitmethodshavebeenwidelyusedinthepasttosolvestiffordinarydifferentialequations.MakinguseofspecialpropertiesofChebyshev-likepolynomials,thesemethodshavefavorablestabilitypropertiescomparedtostandardexplicitmethodswhileremainingexplicit.Anewclassofsuchmethods,calledROCK,introducedin[Numer.Math.,90,1-18,2001]hasrecentlybeenextendedtostiffstochasticdifferentialequationsunderthenameS-ROCK[C.R.Acad.Sci.Paris,345(10),2007andCommun.Math.Sci,6(4),2008].InthispaperwediscusstheextensionoftheS-ROCKmethodstosystemswithdiscretenoiseandproposeanewclassofmethodsforsuchproblems,theT-ROCKmethods.Onemotivationforsuchmethodsisthesimulationofmulti-scaleorstiffchemicalkineticsystemsandsuchsystemsarethefocusofthispaper,butournewmethodscouldpotentiallybeinterestingforotherstiffsystemswithdiscretenoise.TwoversionsoftheT-ROCKmethodsarediscussedandtheirstabilitybehaviorisanalyzedonatestproblem.ComparedtotheT-leapingmethod,asignificantspeed-upcanbeachievedforsomestiffkineticsystems.Thebehavioroftheproposedmethodsaretestedonseveralnumericalexperiments.

  • 标签: 切比雪夫 离散噪声 刚性常微分方程 动力学系统 随机微分方程 ACAD
  • 简介:Inthispaper,standardandeconomicalcascadicmultigridmethodsareconsideredforsolvingthealgebraicsystemsresultingfromthemortarfiniteelementmethods.Bothcascadicmultigridmethodsdonotneedfullellipticregularity,sotheycanbeusedtotacklemoregeneralellipticproblems.Numericalexperimentsarereportedtosupportourtheory.

  • 标签: 有限元方法 迫击炮 多重 瀑布 经济 标准
  • 简介:CascadicmultigridtechniqueformortarWilsonfiniteelementmethodofhomogeneousboundaryvalueplanarlinearelasticityisdescribedandanalyzed.FirstthemortarWilsonfiniteelementmethodforplanarlinearelasticitywillbeanalyzed,andtheerrorestimateunderL2andH1normisoptimal.Thenacascadicmultigridmethodforthemortarfiniteelementdiscreteproblemisdescribed.Suitablegridtrans-feroperatorandsmootheraredevelopedwhichleadtoanoptimalcascadicmultigridmethod.Finally,thecomputationalresultsarepresented.

  • 标签: 平面线性弹性 研钵威尔逊有限元法 多栅技术 弹性力学
  • 简介:Inthepresentpaperweextendthemethodpresentedby0.AxelssonandP.VassilevskicalledAMLPversion(i)ofrecursivelyconstructingpreconditionerforthestiffnessmatrixinthediscretizationofselfadjointsecondorderellipticboundaryvalueproblems.Inourextendedmethodthesystemstobeeliminatedoneachlevelcontainingthemajorblockmatricesofthegivenmatrixcanbesolvedapproximately,whiletheymustbesolvedexactlyintheoriginalmethod.

  • 标签: PRECONDITIONING MULTILEVEL method SCHUR complement.
  • 简介:在这篇论文,我们考虑椭圆形的问题为第二份订单混合了有限元素方法。在最低顺序Brezzi-Douglas-Marini元素的情况中(如果d=2)orBrezzi-Douglas-Duran-Fortin元素(如果d=3)在矩形的平行六面体上,我们证明由合并某些照规则,混合方法系统能作为一个简单、以房间为中心的有限差别方法被写。这导致答案一稀少,positivesemidefinite为未知的数量的线性系统。为一个斜张肌系数,为未知的数量的稀少模式是五个点模板如果d=2,和七如果d=3。为一个一般张肌系数,它是九个点模板,并且十九分别地。是的混合方法实现的应用对的有限差别非等温多相,多,在多孔的媒介的部件流动被介绍。

  • 标签: 有限差分 混合法 误差估计 超收敛 张量系数
  • 简介:在一份以前的报纸,一些特别multistep余弦方法被构造因为能线性地以一个稳定、明确的方法集成,它证明了很有效秒顺序的生硬问题及时。在现在的纸,为这种类型的一般方法的稳定性被给保证的条件,以及回声的彻底的研究并且为对称的过滤(它在另一份报纸,被证明了在Hamiltonian波浪方程关于invariants的保存很有益地表现)。这里被给的,是在提及的方面分析并且对待任何这种类型的方法的一个系统的方法。

  • 标签: 稳定性 共振 多步 刚性问题 二阶线性 波动方程
  • 简介:Handlingindustrialpowdersleadstodustemissions.Theseemissionstendtogeneratehumandiseasesorcauseotherenvironmentaleffects.Amultitudeofapparatushasbeendevelopedtoestimatethisdustinessbehaviourofpowders.Twoofthesewell-knownmethodsarepresentedandcomparedwitheachother.Athirdrecentlydevelopedmethodisalsointroduced.

  • 标签: 颗粒特征 污染度 大气环境 健康危害
  • 简介:AimsandScope:NumericalMathematics:Theory,MethodsandApplications(NM-TMA)publisheshigh-qualityoriginalresearchpapersontheconstruction,analysisandapplicationofnumericalmethodsforsolvingscientificproblems.Importantresearchandexpositorypapersdevotedtothenumericalsolutionofmathematicalproblemsarisinginallareasofscience

  • 标签: 数值方法 数学理论 应用 科学问题 新墨西哥州 研究论文
  • 简介:Anewhigh-ordertime-steppingfiniteelementmethodbaseduponthehigh-ordernumericalintegrationformulaisformulatedforSobolevequations,whosecomputationsconsistofaniterationprocedurecoupledwithasystemoftwoellipticequations.Theoptimalandsuperconvergenceerrorestimatesforthisnewmethodarederivedbothinspaceandintime.Also,aclassofnewerrorestimatesofconvergenceandsuperconvergenceforthetime-continuousfiniteelementmethodisdemonstratedinwhichtherearenotimederivativesoftheexactsolutioninvolved,suchthattheseestimatescanbeboundedbythenormsoftheknowndata.Moreover,someusefula-posteriorierrorestimatorsaregivenonthebasisofthesuperconvergenceestimates.

  • 标签: ERROR ESTIMATES FINITE element SOBOLEV equation
  • 简介:AimsandScope:NumericalMathematics:Theory,MethodsandApplications(NM-TMA)publisheshigh-qualityoriginalresearch

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  • 简介:AimsandScope:NumericalMathematics:Theory,MethodsandApplications(NM-TMA)publisheshigh-qualityoriginalresearchpapersontheconstruction,analysisandapplicationofnumericalmethodsforsolvingscientificproblems.Importantresearchandexpositorypapersdevotedtothenumericalsolutionofmathematicalproblemsarisinginallareasofscienceandtechnologyareexpected.ThejournaloriginatesfromthejournalNumericalMathematics:AJournalofChineseUniversities(EnglishEdition).

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  • 简介:Inthispaper,theauthorsgivesomeapplicationsofF-uniformlydistributedsequences,whicharesuggestedintheirpreviouspaperunderthesametitle,inexperimen-taldesign,experimentswithmixtures,geometricprobabilityandsimulation.

  • 标签: UNIFORMLY MIXTURES UNIFORM GENERA umber PROBABILITY