简介:Someresultsfromthetheoryofbest(orbestsimultaneous)approximationinanarmedlinearspacehavebeenextendedtoanormedalmostlinearspace[strongnormedalmostlinearspace].
简介:AChebyshevfittingwayforapropelleratlasacrossfourquadrantsisdiscussed.Asanexample,Chebyshevpolynomialfittingresultsanditserroranalysisaregiven.Becauseit’sdifficultgenerallytogetapropelleratlasacrossfourquadrants,awayisusedtoconstructanalternativewithhigheraccuracybasedontheproperties.Asanapplicationexample,analternativeforthepropellerpropertyofaDeepSubmergenceVebicleacrossfourquadrantsisgivenpracticallyandasimulationmodelofthe
简介:由于Newman有理算子对|x|逼近效果较好,所以考虑利用Newman-α型有理算子对|x|~α进行逼近.构造Newman-α型有理算子,讨论Newman-α算子在Chebyshev结点组下逼近|x|~α的收敛速度,最后得到精确的逼近阶为O(1/(n~αlogn)).该结果包含了α=1时的情形.
简介:LetB(resp.K,Bl,Kl)denotethesetofallnonemptybounded(resp.compact,boundedconvex,compactconvex)closedsubsetsoftheBanachspaceX,endowedwiththeHausdorffmetric,andletGbeanonemptyrelativelyweaklycompactclosedsubsetofX.LetB°standforthesetofallF∈Bsuchthattheproblem(F,G)iswell-posed.Weprovedthat,ifXisstrictlyconvexandKadec,thesetKl∩B°isadenseG_δ-subsetofKl\G.Furthermore,ifXisauniformlyconvexBanachspace,wewillprovemore,namelythatthesetB\B°(resp.K\B°,Bl\B°,Kl\B°)isa-porousinB(resp.K,Bl,Kl).Moreover,weprovethatformost(inthesenseoftheBairecategory)closedboundedsubsetsGofX,thesetK\B°isdenseanduncountableinK.
简介:文章论证了Chebyshev多项式对零的偏差最小。并利用这一特性构造高精度Chebyshev插值多项式,提高了插值运算精度。
简介:最近,Brutman和Passow认为Newman类型合理插值是to|x|由对称的节点的任意的集合导致了在[-1,1]并且给了近似错误的一般评价。由他们的方法,一个人能为一些特殊节点建立近似的准确顺序。在我们考虑插值节点是第二种类型的零个Chebyshev多项式并且在这种情况中证明那的特殊情况的现在的纸,近似的准确顺序是O(1/(nlnn))。