学科分类
/ 1
7 个结果
  • 简介:ThisarticleconsidersweightedapproximationofmultivariatefunctioninreproducingkernelHilbertspace,andgivesarelationbetweennthminimalerrorsforstandardandlinearinformationintherandomizedsetting.Usingthisrelationwecanestimatethenthminimalerrorforstandardinformationbythenthminimalerrorforlinearinformation,andstudythetractabilityandstrongtractabilityforthesetwoclassesofinformation.

  • 标签: 信息基复杂度 多元近似 易处理性 HILBERT空间 蒙特卡罗方法 随机设置
  • 简介:Theauthorsdefinethesceneryflowofthetorus.Theflowspaceistheunionofallflat2-dimensionaltoriofarea1withamarkeddirection(orequivalently,theunionofalltoriwithaquadraticdifferentialofnorm1).Thisisa5-dimensionalspace,andtheflowactsbyfollowingindividualpointsunderanextremaldeformationofthequadraticdifferential.Theauthorsdefineassociatedhorocycleandtranslationflows;thelatterpreserveeachtorusandarethehorizontalandverticalflowsofthecorrespondingquadraticdifferential.Thesceneryflowprojectstothegeodesicflowonthemodularsurface,andadmits,foreachorientationpreservinghyperbolictoralautomorphism,aninvariant3-dimensionalsubsetonwhichitisthesuspensionflowofthatmap.Theauthorsfirstgiveasimplealgebraicdefinitionintermsofthegroupofaffinemapsoftheplane,andprovethattheflowisAnosov.Theygiveanexplicitformulaforthefirst-returnmapoftheflowonconvenientcross-sections.Then,inthemainpartofthepaper,theauthorsgiveseveraldifferentmodelsfortheflowanditscross-sections,intermsof:●stackingandrescalingperiodictilingsoftheplane;●symbolicdynamics:thenaturalextensionoftherecodingofSturmiansequences,ortheS-adicsystemgeneratedbytwosubstitutions;●zoomingandsubdividingquasi-periodictilingsoftherealline,oraperiodicquasicrystalsofminimalcomplexity;●thenaturalextensionoftwo-dimensionalcontinuedfractions;●inductiononexchangesofthreeintervals;●rescalingonpairsoftransversemeasurefoliationsonthetorus,ortheTeichmiillerflowonthetwice-puncturedtorus.

  • 标签: 模面 动力系统 连分数 平面贴砖 Teichmuller流 Sturm序列
  • 简介:WeshowthatmanyharmonicanalysisoperatorsintheBesselsetting,includingmaximaloperators,Littlewood–Paley–Steintypesquarefunctions,multipliersofLaplaceorLaplace–StieltjestransformtypeandRiesztransformsare,orcanbeviewedas,Calderón–Zygmundoperatorsforallpossiblevaluesoftypeparameterλinthiscontext.Thisextendsresultsexistingintheliterature,butbeingjustifiedonlyforarestrictedrangeofλ.

  • 标签: D算子 类型 设置 塞尔 RIESZ变换 拉普拉斯
  • 简介:Inthispaper,westudyoptimalrecovery(reconstruction)offunctionsonthesphereintheaveragecasesetting.WeobtaintheasymptoticordersofaveragesamplingnumbersofaSobolevspaceonthespherewithaGaussianmeasureintheLd-1q(S)metricfor1≤q≤∞,andshowthatsomeworst-caseasymptoticallyoptimalalgorithmsarealsoasymptoticallyoptimalintheaveragecasesettingintheLdq(S-1)metricfor1≤q≤∞.

  • 标签: SOBOLEV空间 测量范围 平均数 最优恢复 球面函数 设置
  • 简介:这篇论文为第一份订单的夸张椭圆形的联合系统的边界值问题被奉献给边界条件的合适的设置的学习。相应边界价值问题的wellposedness也被建立。为椭圆形的系统的边界价值问题的Lopatinski条件然后为夸张椭圆形的联合系统被扩大到盒子。在这篇论文的结果能在液体动力学被用于Euler系统,到特别给描述亚声的流动的很好提出的边界价值问题。

  • 标签: 边界值问题 双曲线 椭圆 数学
  • 简介:ManyworkshaveinvestigatedtheproblemofreparameterizingrationalBéziercurvesorsurfacesviaMbiustransformationtoadjusttheirparametricdistributionaswellasweights,suchthatthemaximalratioofweightsbecomessmallerthatsomealgebraicandcomputationalpropertiesofthecurvesorsurfacescanbeimprovedinaway.However,itisanindicationofveracityandoptimizationofthereparameterizationtodopriortojudgewhetherthemaximalratioofweightsreachesminimum,andverifythenewweightsafterMbiustransformation.What’smoretheusersofcomputeraideddesignsoftwaresmayrequiresomeguidelinesfordesigningrationalBéziercurvesorsurfaceswiththesmallestratioofweights.Inthispaperwepresentthenecessaryandsufficientconditionsthatthemaximalratioofweightsofthecurvesorsurfacesreachesminimumandalsodescribeitbyusingweightssuccinctlyandstraightway.Theweightsbeingsatisfiedtheseconditionsarecalledbeinginthestablestate.Applyingsuchconditions,anygivingrationalBéziercurveorsurfacecanautomaticallybeadjustedtocomeintothestablestatebyCADsystem,thatis,thecurveorsurfacepossessesitsoptimalparametricdistribution.Finally,wegivesomenumericalexamplesfordemonstratingourresultsinimportantapplicationsofjudgingthestablestateofweightsofthecurvesorsurfacesanddesigningrationalBéziersurfaceswithcompactderivativebounds.

  • 标签: 贝塞尔曲线 计算机辅助设计软件 曲面 有理 重量 稳态