简介:利用矩阵Schur补的性质,建立了若干关于半正定矩阵Hadamard乘积和普通加法的矩阵不等式,推广了相应的结果。
简介:利用半正定矩阵的性质和矩阵Moore-Penrose广义逆的特性,研究了半正定矩阵广义Schur补问题.证明了对半正定矩阵A有(A/α)*(A/α)≥A*A/α,并由此得到了一些有关广义Schur补的不等式.将半正定矩阵Schur补的相关结果推广至广义Schur补.
简介:ItisprovedthattheChebyshevpolynomial_n(x)=T_n(xcosπ/2n),hasthegreatestuniformnormon[-1,1]ofitsthirdderivativeamongtherealpolynomialsofdegreeatmostn,whichareboundedby1in[-1,1]andvanishin-1and1.
简介:讨论了一个Seiffert平均在R2++上的Schur凸性和Schur几何凸性,并建立了两个新的不等式链.
简介:为x=(x1,x2,,xn)+nn,对称的功能Fn(x,r)并且Gn(x,r)被$$F_n定义(x,r)=F_n(x_1,x_2,\cdots,x_n;r)=\sum\limits_{1\leqslanti_1and$$G_n(x,r)=G_n(x_1,x_2,\cdots在这份报纸,F的Schur凸状<潜水艇class=“a-plus-plus”>n(x,r)并且G<潜水艇class=“a-plus-plus”>n(x,r)被讨论。作为应用程序,由为一个Schur凸的函数的独立变量的bijective转变,作者为一些另外的对称的函数获得Schur凸状,它在最近的文学包含主要结果;并且由majorization的理论的使用建立一些不平等。特别地,作者从这份报纸的结果导出Weierstrass不平等和Ky扇子不平等,并且给Saftas的归纳在n维的空间和其它推测。
简介:InthispaperwestudythecomputationalperformanceofvariantsofanalgebraicadditiveSchwarzpreconditionerfortheSchurcomplementforthesolutionoflargesparselinearsystems.Inearlierworks,thelocalSchurcomplementswerecomputedexactlyusingasparsedirectsolver.Therobustnessofthepreconditionercomesatthepriceofthismemoryandtimeintensivecomputationthatisthemainbottleneckoftheapproachfortacklinghugeproblems.InthisworkweinvestigatetheuseofsparseapproximationofthedenselocalSchurcomplements.TheseapproximationsarecomputedusingapartialincompleteLUfactorization.Suchanumericalcalculationisthecoreofthemulti-levelincompletefactorizationsuchastheoneimplementedinpARMS.Thenumericalandcomputingperformanceofthenewnumericalschemeisillustratedonasetoflarge3Dconvection-diffusionproblems;preliminaryexperimentsonlinearsystemsarisingfromstructuralmechanicsarealsoreported.
简介:AparallelhybridlinearsolverbasedontheSchurcomplementmethodhasthepotentialtobalancetherobustnessofdirectsolverswiththeefficiencyofpreconditionediterativesolvers.However,whensolvinglarge-scalehighly-indefinitelinearsystems,thishybridsolveroftensuffersfromeitherslowconvergenceorlargememoryrequirementstosolvetheSchurcomplementsystems.Toovercomethischallenge,weinthispaperdiscusstechniquestopreprocesstheSchurcomplementsystemsinparallel.Numericalresultsofsolvinglarge-scalehighly-indefinitelinearsystemsfromvariousapplicationsdemonstratethatthesetechniquesimprovethereliabilityandperformanceofthehybridsolverandenableefficientsolutionsoftheselinearsystemsonhundredsofprocessors,whichwaspreviouslyinfeasibleusingexistingstate-of-the-artsolvers.