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35 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:Weraiseandpartlyanswerthequestion:whetherthereexistsaMarkovsystemwithrespecttowhichthezerosoftheChebyshevpolynomialsaredense,butthemaximumlengthofazerofreeintervalofthenthChebyshevpolynomialdoesnottendstozero.Wealsodrawtheconclu-tionthataMarkovsystem,underanadditionalassumption,isdenseifandonlyifthemaxi-mumlengthofazerofreeintervalofthenthassociatedChebyshevpolynomialtendstozero.

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  • 简介:Inthispaper,weestablishanewtypeofalternationtheoryformoregeneralrestrictedrangesChebyshevapproximationwithequalities.Theuniquenessandstronguniquenesstheoremsaregiven.Applyingtheresults,weobtainthealternationtheoremanduniquenesstheoremforbestcoposiliveapproximation.

  • 标签: Chebyshev APPROXIMATION generaized Haar SUBSPACE RESTRICTED
  • 简介:本文引进带权的Chcbyshev逼近并给出它的应用。

  • 标签: 逼近 引进 应用
  • 简介:ONEXCHANGEALGORITHMFORNONLINEARBESTCHEBYSHEVAPPROXIMATIONWITH LGHCONDITIONXiongGuijing(熊规景);WeiDan(韦旦)(Inst.ofMath.Sci.,Chin....

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  • 简介:性质awc1被许多作者使用由弱Chebyshevsubspaces的元素有关近似获得结果。在这份报纸,作者在细节学习这个性质,由收集有关它并且由发现新的散布结果。

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  • 简介:Thepaperproposesanovelalgorithmtogettheencryptionmatrix.Firstly,achaoticsequencegeneratedbyChebyshevchaoticneuralnetworksisconvertedintoaseriesoflow-orderintegermatricesfromwhichavailableencryptionmatricesareselected.Then,ahigherorderencryptionmatrixrelatingrealworldapplicationisconstructedbymeansoftensorproductionmethodbasedonselectedencryptionmatrices.Theresultsshowthattheproposedalgorithmcanproducea'one-timepadcipher'encryptionmatrixwithhighsecurity;andtheencryptionresultshavegoodchaosandauto-correlationwiththenaturalfrequencyoftheplaintextbeinghiddenandhomogenized.

  • 标签: CHEBYSHEV 混沌神经网络 整数矩阵 加密 构造方法 应用程序
  • 简介:本文将熟知的Chebyshev不等式[1](p.216)推广到n维函数序列与向量函数的情形,并将其中对函数所加的条件减弱。此外,还推得了若干著名的不等式和给出了一些应用。

  • 标签: n维函数序列 向量函数 似序 反序
  • 简介:Someresultsfromthetheoryofbest(orbestsimultaneous)approximationinanarmedlinearspacehavebeenextendedtoanormedalmostlinearspace[strongnormedalmostlinearspace].

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  • 简介:AChebyshevfittingwayforapropelleratlasacrossfourquadrantsisdiscussed.Asanexample,Chebyshevpolynomialfittingresultsanditserroranalysisaregiven.Becauseit’sdifficultgenerallytogetapropelleratlasacrossfourquadrants,awayisusedtoconstructanalternativewithhigheraccuracybasedontheproperties.Asanapplicationexample,analternativeforthepropellerpropertyofaDeepSubmergenceVebicleacrossfourquadrantsisgivenpracticallyandasimulationmodelofthe

  • 标签: PROPELLER FOUR quadrants PROPERTY dynamic simulation
  • 简介:由于Newman有理算子对|x|逼近效果较好,所以考虑利用Newman-α型有理算子对|x|~α进行逼近.构造Newman-α型有理算子,讨论Newman-α算子在Chebyshev结点组下逼近|x|~α的收敛速度,最后得到精确的逼近阶为O(1/(n~αlogn)).该结果包含了α=1时的情形.

  • 标签: 有理逼近 Chebyshev结点 Newman-α型有理算子
  • 简介:LetB(resp.K,Bl,Kl)denotethesetofallnonemptybounded(resp.compact,boundedconvex,compactconvex)closedsubsetsoftheBanachspaceX,endowedwiththeHausdorffmetric,andletGbeanonemptyrelativelyweaklycompactclosedsubsetofX.LetB°standforthesetofallF∈Bsuchthattheproblem(F,G)iswell-posed.Weprovedthat,ifXisstrictlyconvexandKadec,thesetKl∩B°isadenseG_δ-subsetofKl\G.Furthermore,ifXisauniformlyconvexBanachspace,wewillprovemore,namelythatthesetB\B°(resp.K\B°,Bl\B°,Kl\B°)isa-porousinB(resp.K,Bl,Kl).Moreover,weprovethatformost(inthesenseoftheBairecategory)closedboundedsubsetsGofX,thesetK\B°isdenseanduncountableinK.

  • 标签: Chebyshev中心点 不确定轨迹 非空界限 BANACH空间
  • 简介:我们开发并且分析一个一阶的系统最少平方光谱为秒顺序的方法有可变系数的椭圆形的边界价值问题。我们首先分析theChebyshev加权的标准最少平方功能由L_ω~2-1)-norm和H_ω~的和定义(方程然后我们代替的剩余的-1)-norm由分离否定标准和分析的否定标准分离Chebyshev加权的最少平方的方法。光谱集中为建议方法被导出。我们也介绍各种各样的数字实验。Legendreweighted最少平方的方法能被跟随这篇论文容易开发。

  • 标签: 最小平方法 光谱法 否定标准 变量系数 数学分析