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33 个结果
  • 简介:Considersolvinganoverdeterminedsystemoflinearalgebraicequationsbyboththeleastsquaresmethod(LS)andthetotalleastsquaresmethod(TLS).Extensivepublishedcomputationalevidenceshowsthatwhentheoriginalsystemisconsistent.oneoftenobtainsmoreaccuratesolutionsbyusingtheTLSmethodratherthantheLSmethod.ThesenumericalobservationscontrastwithexistinganalyticperturbationtheoriesfortheLSandTLSmethodswhichshowthattheupperboundsfortheLSsolutionarealwayssmallerthanthecorrespondingupperboundsfortheTLSsolutions.InthispaperwederiveanewupperboundfortheTLSsolutionandindicatewhentheTLSmethodcanbemoreaccuratethantheLSmethod.Manyappliedproblemsinsignalprocessingleadtooverdeterminedsystemsoflinearequationswherethematrixandrighthandsidearedeterminedbytheexperimentalobservations(usuallyintheformofalimeseries).Itoftenhappensthatasthenumberofcolumnsofthematrixbecomeslarger,thera

  • 标签: Least SQUARES TOTAL least SQUARES ACCURACY
  • 简介:AnegativecurvaturemethodisappliedtononlinearleastsquaresproblemswithindefiniteHessianapproximationmatrices.Withthespecialstructureofthemethod,anewswitchisproposedtoformahybridmethod.Numericalexperimentsshowthatthismethodisfeasibleandeffectiveforzero-residual,small-residualandlarge-residualproblems.

  • 标签: 杂交法 最小二乘问题 非线性 曲率 数值逼近
  • 简介:Thispaperdiscussespointwiseerrorestimatesfortheapproximationbyboundedlinearoperatorsofcontinuousfunctionsdefinedoncompactmetricspaces(X,d),Theauthorsintroduceanewmajorautofthemodulusofthecontinuitywhichisthesrnallestamongthoseg(ξ)'swhichhavethefollowingpropertiesω(f,ε)≤9(f,ε)andg(f,λε)≤(1+λ)g(f,ε)andbythismajorantanewquantitativeKorovkintypetheoremonanycompactmetricspaceisproved.

  • 标签: 最小支配连续模 数值近似 紧空间 有界线性算子
  • 简介:一张签署的图是一张图,一个符号属于每个边。这篇论文从图扩大拉普拉斯算符矩阵的一些基本概念到签署的图。Inparticular,在最少的拉普拉斯算符特征值之间的关系和一张签署的图的失衡的海角被调查。

  • 标签: LAPLACIAN算子 特征值 符号图 LAPLACIAN矩阵
  • 简介:Inthispaper,wepresentsomeiterativemethodsforsolvinglthorderautoregressivemodels,proveglobalconvergenceforl=1case,andthenumericalresultsofnewalgorithmsseemtobemoreefficientthantheonesofCochrane-Orcuttiterativemethod.

  • 标签: AUTOREGRESSIVE MODEL ITERATIVE METHOD convergence.
  • 简介:TheGalerkinandleast-squaresmethodsaretwoclassesofthemostpopularKrylovsubspacemethOdsforsolvinglargelinearsystemsofequations.Unfortunately,boththemethodsmaysufferfromseriousbreakdownsofthesametype:InabreakdownsituationtheGalerkinmethodisunabletocalculateanapproximatesolution,whiletheleast-squaresmethod,althoughdoesnotreallybreakdown,isunsucessfulinreducingthenormofitsresidual.Inthispaperwefrstestablishaunifiedtheoremwhichgivesarelationshipbetweenbreakdownsinthetwometh-ods.Wefurtherillustratetheoreticallyandexperimentallythatifthecoefficientmatrixofalienarsystemisofhighdefectivenesswiththeassociatedeigenvalueslessthan1,thentherestart-edGalerkinandleast-squaresmethodswillbeingreatrisksofcompletebreakdowns.Itappearsthatourfindingsmayhelptounderstandphenomenaobservedpracticallyandtoderivetreat-mentsforbreakdownsofthistype.

  • 标签: large linear systems iterative methods Krylov
  • 简介:Weproveconvergenceforameshfreefirst-ordersystemleastsquares(FOSLS)partitionofunityfiniteelementmethod(PUFEM).Essentially,byvirtueofthepartitionofunity,localapproximationgivesrisetoglobalapproximationinH(div)∩H(curl).TheFOSLSformulationyieldslocalaposteriorierrorestimatestoguidethejudiciousallotmentofnewdegreesoffreedomtoenrichtheinitialpointsetinameshfreedis-cretization.Preliminarynumericalresultsareprovidedandremainingchallengesarediscussed.

  • 标签: 适应有限元 最小方程式 数学模型 计算数学
  • 简介:LetMbeacompactorientable3-manifoldwithMconnected.IfV∪SWisaHeegaardsplittingofMwithdistanceatleast6,thenthe-stabilizationofV∪SWalongMisunstabilized.HenceMhasatleasttwounstabilizedHeegaardsplittingswithdifferentgenera.ThebasictoolisaresultondiskcomplexgivenbyMasurandSchleimer.

  • 标签: 不稳定 距离 劈裂 Heegaard分裂 镇定 络合物
  • 简介:LetG=(V(G),E(G))beasimpleconnectedgraphofordern.Foranyverticesu,v,w∈V(G)withuv∈E(G)anduw∈E(G),anedge-rotatingofGmeansrotatingtheedgeuv(aroundu)tothenon-edgepositionuw.Inthiswork,weconsiderhowtheleasteigenvalueofagraphperturbswhenthegraphisperformedbyrotatinganedgefromtheshorterhangingpathtothelongerone.

  • 标签: 最小特征值 旋转定理 简单连通图 紫外线 顶点
  • 简介:Byusingthenon-parametricleastsquaremethod,thestrongconsistentestimationsofdistributionfunctionandfailurefunctionareestablished,wherethedistributionfunctionF(x)afterlogisttransformationisassumedtobeapproximatedbyapolynomial.Theperformanceofsimulationshowsthattheestimationsarehighlysatisfactory.

  • 标签: 分布函数 最小二乘 估计 非参数
  • 简介:Inthispaperwepresentanonmonotonetrustregionmethodfornonlinearleastsquaresproblemswithzero-residualandproveitsconvergenceproperties.Theextensivenumericalresultsarereportedwhichshowthatthenonmonotonetrustregionmethodisgenerallysuperiortotheusualtrustregionmethod.

  • 标签: TRUST REGION METHOD NONLINEAR least SQUARES
  • 简介:为相对主要的积极整数u0并且r,并且为0kn,定义uk:=u0+kr。让Ln:=最小公倍数(u0,u1,...,un)并且让一,2是的l任何整数。在这份报纸,作者显示出那,为整数一,r最大(一,l1)并且nlr,下列不平等抓住$$L_n\geqslantu_0r^{\left({l-1}\right)\alpha+一-l}\left({r+1}\right)^n.$$特别地,让3产出的l=Ln上的以前的更低的界限在2010由hong和Kominers获得了的最好上的改进。

  • 标签: 最小公倍数 算术级数 下界 正整数 联合国 最大值
  • 简介:Thefollwingsituationinusingthemethodofleastsquarestosolveproblemsoftenoccurs.Aftermexperimentscompletedandasolutionofleastsquaresobtained,the(m+1)-thexperimentismadefurtherinordertoimprovetheresults.Amethodofalgebraicoperationofspecialmatricesinvoledintheproblemisgivenisthispaperforobtaininganewsolutionforthem+1experimentsbasedupontheoldsolutionfortheprimarymexperiments.Thismethodisvalidformoregeneralmatrices.

  • 标签: 最小二乘法 矩阵运算 实验 形式幂级数
  • 简介:WeextendtheobliqueprojectionmethodgivenbyY.Saadtosolvethegeneralizedleastsquaresproblem.Thecorrespondingobliqueprojectionoperatorispresentedandtheconvergencetheoremsareproved.SomenecessaryandsufficientconditionsforcomputingthesolutionortheminimumN-normsolutionofthemin||Ax-b||M2havebeenproposedaswell.

  • 标签: OBLIQUE projection method GENERALIZED least SQUARES
  • 简介:Analgorithmforsolvingnonlinearleastsquaresproblemswithgenerallinearinequalityconstraintsisdescribed.Ateachstep,theproblemisreducedtoanunconstrainedlinearleastsquaresprobleminasubspacedefinedbytheactiveconstraints,whichissolvedusingthequasi-Newtonmethod.ThemajorupdateformulaissimilartotheonegivenbyDennis,GayandWelsch(1981).Inthispaper,westatethedetailedimplementofthealgorithm,suchasthechoiceofactiveset,thesolutionofsubproblemandtheavoidanceofzigzagging.Wealsoprovethegloballyconvergentpropertyofthealgorithm.

  • 标签: nonlinear least SQUARES linear INEQUALITY CONSTRAINTS
  • 简介:AbstractIntheparametertrackingoftime-varyingsystems,theordinarymethodisweightedleastsquareswiththerectangularwindowortheexponentialwindow.Inthispaperweproposeanewkindofslidingwindowcalledthemultipleexponentialwindow,andthenuseittofittime-varyingGaussianvectorautoregressivemodels.Theasymptoticbiasandcovarianceoftheestimatoroftheparameterfortime-invariantmodelsarealsoderived.Simulationresultsshowthatthemultipleexponentialwindowshavebetterparametertrackingeffectthanrectangularwindowsandexponentialones.

  • 标签: EXPONENTIAL WINDOW rectangular WINDOW MULTIPLE EXPONENTIAL
  • 简介:有自我地图f的n周期的点的数字的二代数学的更低的界限:一个协议的MM变光滑尺寸歧管至少3:NF<潜水艇class=“a-plus-plus”>n(f)=min{#Fix(g<啜class=“a-plus-plus”>n);gf;g是连续的}并且NJD<潜水艇class=“a-plus-plus”>n(f)=min{#Fix(g<啜class=“a-plus-plus”>n);gf;g是光滑的}。一般来说,NJD<潜水艇class=“a-plus-plus”>n(f)可能比NF大得多<潜水艇class=“a-plus-plus”>n(f)。如果M是一个花托,那么,invariants是相等的。我们证明为一个nonabelian协议谎言组的一张自我地图,与自由的基本的组一起,平等保持f导致的商cohomology同形的所有特征值有moduli1。

  • 标签: 周期点 李群 地图 自映射 不变量 阿贝尔