简介:这份报纸为最好的制服处理Kolmogorov标准coapproximation和强烈独特的最好的一致coapproximation。在最好的一致近似和最好的一致coapproximation之间的一些关系被获得。一些平等和最好的一致coapproximation被连接。
简介:ONM-IDEALSANDBESTAPPROXIMATIONHANDEGUANG(韩德广)(DepartmentofMathematics,QufuNormalUniversity,Qufu273165,China)Abstract:Inthispa...
简介:我们开发一个理论向下,为normed的一个类的集合订了空格。在normed的Westudy最好的近似由元素订了空间X向下设定,并且为最好的近似的任何元素给必要、足够的条件由一向下关门了X的子集。我们也向下严格地描绘X的子集,并且证明那一向下X的子集严格地是向下如果并且仅当每它的边界点是Chebyshev。获得的结果被用于一些Chebyshev对的检查(W,x),x∈X和W在此一向下关门了X的子集。
简介:Inthispaper,weintroduceaconditionweakerthantheLpdifferentiability,whichwecallCpcondition.Weprovethatifafunctionsatisfiesthisconditionatapoint,thenthereexiststhebestlocalapproximationatthatpoint.WealsogiveanecessaryandsufficientconditionforthatafunctionbeLpdifferentiable.Inaddition,westudytheconvexityofthesetofclusterpointsofthenetofbestappoximationsoff,{Pe(f)}ase→0.
简介:在里面[加拿大数学。公牛。22,pp。513515,1979],作者延长了一有趣(最好的近似)Ky扇子的定理[看见定理2,数学。Z。112,pp。234240]到在一个Banach空格在一个关上的球定义并且在一个Hilbert空格在一个关上的凸的子集上定义的压缩地图。在里面[J。近似理论52,pp。141148,1988],作者和日元进一步在一个Hilbert空格扩大了它到1-set-contractive地图。在这份报纸,我们将探讨几个相关问题。首先,我们扩大林,日元为1-set-contractive地图,但是到结果满足更弱的状况,它允许我们包括概括收缩地图。第二,我们让路为nonexpansive地图构造最好的近似(不仅仅存在结果)。第三,我们给上的条件最好的近似{un|n=1,2,}收缩的一个序列{fn|n=1,2,}将收敛到收缩f的最好的近似u。第四,为nonexpansive地图的普通最好的近似定理被证明。到为弱里面的地图和其它的固定的点定理的应用为所有那些四个话题被给。
简介:GivenacontinuousfunctionfdefinedontheunitcubeofRnandaconvexfunctiont,t(0)-0,t(x)>0,forx>0,weprovethatthesetofbestLt-approximationsbymonotonefunctionshasexactlyoneelementft,whichisalsoacontinuousfunction.Moreoverifthefamilyofconvexfunctions{t}t>0convergesuniformlyoncompactsetstoafunction0,thenthebestapproximationft→f0uniformly,ast→0,wherefoisthebestapproximationoffwithintheOrliczspaceL0Thebestapproxima-tions{ft}areobtainedaswellasminimizingintegralsortheLuxemburgnorm
简介:Thispapergivesageneralcharacterizationtheoremofabestuniformapproximationofgeneralizedpolynomialhavingmultiplerestrictedrangesofitsderivatives.Thistheoremiswidelyapplicable.Theresultsoncharacterizationinmanystandardapproximations,suchasapproximationwithHermite-Birkhoffinterpolatorysideconditions,multiplecomonotoneapproximation,andapproximationbyalgebraicpolynomialshavingboundedcoefficients,etc.,arespecialcasesofourresult.
简介:ForasubsetKofametricspace(X,d)andx∈X,PK(x)={y∈K:d(x,y)=d(x,K)≡inf{d(x,k):k∈K}}iscalledthesetofbestK-approximanttox.Anelementg。∈Kissaidtobeabestsimultaneousapproximationofthepairy1,y2∈Xifmax{d(y1,g。),d(y2,g。)}=infg∈Kmax{d(y1,g),d(y2,g)}.Inthispaper,someresultsontheexistenceofcommonfixedpointsforBanachoperatorpairsintheframeworkofconvexmetricspaceshavebeenproved.ForselfmappingsTandSonK,resultsareprovedonbothT-andS-invariantpointsforasetofbestsimultaneousapproximation.SomeresultsonbestK-approximantarealsodeduced.TheresultsprovedgeneralizeandextendsomeresultsofI.BegandM.Abbas[1],S.ChandokandT.D.Narang[2],T.D.NarangandS.Chandok[11],S.A.Sahab,M.S.KhanandS.Sessa[14],P.Vijayaraju[20]andP.VijayarajuandM.Marudai[21].
简介:在这份报纸,积极明确的矩阵functionals在一套方形的integrable矩阵上定义珍视的功能被介绍并且学习。最好的近似问题以矩阵Fourier系列被解决。Riemann-Lebesgue矩阵性质和Bessel-Parseval矩阵不平等被给。
简介:Inthispapertheconceptofpositivedefinitebilinearmatrixmomentfunctional.actingonthespaceofallthematrixvaluedcontinuousfunctionsdefinedonaboundedinterval[a,b],isintroduced.ThebestapproximationmatrixproblemwithrespecttosuchafunctionalissolvedintermsofmatrixFourierseries.BasicpropertiesofmatrixFourierseriessuchastheKiemann-Lebesguematrixpropertyandthebessel-parsevalmatrixinequalityareproved.Theconceptoftotalsetvjithrespecttoapositivedefinitematrixfunctionalisintroduced,andthetotallityofanorthonormalsequenceofmatrixpolynomialswithrespecttothefunctional,isestablished.
简介:Inanabstractsetup,wegetstrongtypeinequalitiesinL~(p+1)byassumingweakorextra-weakinequalitiesinOrliczspaces.Forsomeclassesoffunctions,thenumberpisrelatedtoSimonenkoindices.WeapplytheresultstogetstronginequalitiesformaximalfunctionsassociatedtobestΦ-approximationoperatorsinanOrliczspaceL~Φ.
简介:ONEXCHANGEALGORITHMFORNONLINEARBESTCHEBYSHEVAPPROXIMATIONWITH LGHCONDITIONXiongGuijing(熊规景);WeiDan(韦旦)(Inst.ofMath.Sci.,Chin....