简介:SupposethatwewanttoapproximatefC[0,1]bypolynomialsinPn,usingonlyitsvaluesonXn={i/n,0≤i≤n}.ThiscanbedonebytheLagrangeinterpolantLnfortheclassicalBernsteinpolynomialBnf.But,whenntendstoinfinity,LnfdoesnotconvergetofingeneralandtheconvergenceofBnftofisveryslow.WedefineafamilyofoperatorsBkn,n≥k,whichareintermediateonesbetweenB(0)n=B1n=BnandBnn=Ln,andwestudysomeoftheirproperties.Inparticular,weproveaVoronovskaja-typetheoremwhichassertsthatBknf-f=0(n-[(k+2)/2)forfsufficientlyregular.Moreover,B(k)nfusesonlyvaluesofBnfanditsderivatiesandcanbecomputedbyDeCasteljauorsubdivisionalgorithms.
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。
简介:TwoestimatesusefulinapplicationsareprovedfortheFouriertransforminthespaceL2(X),whereXasymmetricspace,asappliedtosomeclassesoffunctionscharacterizedbyageneralizedmodulusofcontinuity.
简介:K1,k┐FACTORIZATIONOFBIPARTITEGRAPHSDUBEILIANGAbstract.Inthispaper,anecessaryconditionforabipartitegraphλKm,ntobeK1,k-factoriz...
简介:Anticipatedbackwardstochasticdifferentialequation(ABSDE)studiedthefirsttimein2007isanewtypeofstochasticdifferentialequations.Inthispaper,weestablishageneralcomparisontheoremforABSDEs.
简介:Radialfunctionshavebecomeausefultoolinnumericalmathematics.Onthespheretheyhavetobeidentifiedwiththezonalfunctions.Weinvestigatezonalpolynomialswithmassconcentrationatthepole,inthesenseoftheirL1-normisattainingtheminimumvalue.Suchpolynomialssatisfyacomplicatedsystemofnonlineare-quations(algebraicifthespacedimensionisodd,only)andalsoasingulardifferentialequationofthirdorder.Theexactorderofdecayoftheminimumvaluewithrespecttothepolynomialdegreeisdetermined.Byourresultswecanprovethatsomenodalsystemsonthesphere,whicharedefinedbyaminimum-property,areprovidingfundamentalmatriceswhicharediagonal-dominantorboundedwithrespecttothe∞-norm,atleast,asthepolynomialdegreetendstoinfinity.
简介:<正>Inthisnote.wewillshowthatnononuniformlatticeofSO(3,1)canbethefundamentalgroupofaquasi-compactKhlermanifold.Thus,combiningwiththeresultin[1].onegetsthatanonuniformlatticeinSO(n,1)(n≥3)cannotbeπ1ofanyquasi-compactKhlerianmanifold.
简介:“最近发展区”这一概念是由前苏联教育家维果茨基首先提出的,它是指学生现有水平和潜在发展水平之间的最小差异区域.所谓现有水平,是由已完成的发展系统形成的学生心理机能的发展水平,表现为学生能够独立地、自由地完成教师提出的智力任务.潜在发展水平,是那些尚处于形成状态,表现为学生还不能独立完成,但在教师的帮助下,通过自己的努力所能达到的较高一层的智力发展区.简单来说,“最近发展区”就是:如果你现在站在的是“已有知识”的草坪上,树上的桃子是你“将要学会的知识”,而桃子生长的地方,你站着是摘不着的,其间有个区域就是“最近发展区”.要摘下桃子,必须跳一跳,至于需要跳多高,则因人而异.