简介:Wewilldefineandcharacterizeε-pseudoChebyshevandε-quasiChebyshevsubspacesofBanachspaces.WewillprovethataclosedsubspaceWisε-pseudoChebyshevifandonlyifWisε-quasiChebyshev.
简介:
简介:Weraiseandpartlyanswerthequestion:whetherthereexistsaMarkovsystemwithrespecttowhichthezerosoftheChebyshevpolynomialsaredense,butthemaximumlengthofazerofreeintervalofthenthChebyshevpolynomialdoesnottendstozero.Wealsodrawtheconclu-tionthataMarkovsystem,underanadditionalassumption,isdenseifandonlyifthemaxi-mumlengthofazerofreeintervalofthenthassociatedChebyshevpolynomialtendstozero.
简介:Inthispaper,weestablishanewtypeofalternationtheoryformoregeneralrestrictedrangesChebyshevapproximationwithequalities.Theuniquenessandstronguniquenesstheoremsaregiven.Applyingtheresults,weobtainthealternationtheoremanduniquenesstheoremforbestcoposiliveapproximation.
简介:在一致凸的Banach空间中,采用新的证明方法研究了严格渐近伪压缩映象和渐近非膨胀映象带误差的修正的Mann和Ishikawa迭代程序的收敛性问题,不要求定义域、值域有界,且迭代系数更简单.
简介:设X是一致光滑的Banach空间,T:D(T)属于X→2^x是局部严格伪压缩映射且有不动点.设Q是从X到D(T)上的非扩张保核映射.任取x0∈D(T)归纳定义:xn+1=Qpл,pn∈(1-cn)xn+cnTQyn,yn∈(1-dn)xn+dnTxn.如果存在有界序列{wn}和{zn},wn∈TQyn,zn∈Txn.则{xn}强收敛于T的唯一不动点.其中数列{cn}和{dn}满足适当条件.
简介:ONEXCHANGEALGORITHMFORNONLINEARBESTCHEBYSHEVAPPROXIMATIONWITH LGHCONDITIONXiongGuijing(熊规景);WeiDan(韦旦)(Inst.ofMath.Sci.,Chin....
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:Itwillbedeterminedunderwhatconditionstypesofproximinalityaretransmittedtoandfromquotientspaces.Inthefinalsection,bymanyexamplesweshowthattypesofproximinalityofsubspacesinBanachspacescannotbepreservedbyequivalentnorms.