简介:Inthisarticle,wewillinvestigatethepropertiesofiterativesequencefornon-expansivemappingsandpresentseveralstrongandweakconvergenceresultsofsuccessiveapproximationstofixedpointsofnon-expansivemappingsinuniformlyconvexBanachspaces.Theresultspresentedinthisarticlegeneralizeandimprovevariousonesconcernedwithconstructivetechniquesforthefixedpointsofnon-expansivemappings.
简介:在一致凸Banach空间上,研究了半紧的非扩张压缩映象||Tx-Ty||≤||x-y||的Ishikawa型的三重迭代序列的收敛性问题,建立并证明了带误差的Ishikawa三重迭代逼近收敛定理,从而独特的推广了Mann和Ishikawa迭代方法,改进和发展了文献[1]-[7]的主要结果.
简介:WeextendtheconceptofframemultiresolutionanalysistoalocallycompactabeliangroupanduseittodefinecertainweightedBanachspacesandthespacesoftheirantifunctionals.Wedefineanalysisandsynthesisoperatorsonthesespacesandestablishthecontinuityoftheircomposition.Also,weproveageneralresulttocharacterizeinfinitetreesintheaboveBanachspacesofantifunctionals.ThispaperpavesthewayforthestudyofcorrespondingproblemsassociatedwithsomeothertypesofBanachspacesonlocallycompactabeliangroupsincludingmodulationspaces.
简介:Inthispaper,westudyanoperatorswhichmapseveryn-by-nsymmetricmatrixA,toamatrixs(A_n)thatminimizes||B_n-A_n||FoverthesetofallmatricesB_n,thatcanbediagonalizedbythesinetransform.Thematrixs(A_n),calledtheoptimalsinetransformpreconditioner,isdefinedforanyn-by-nsymmetricmatricesA_n.Thecostofconstructings(A_n)isthesameasthatofoptimalcirculantpreconditionerc(A_n)whichisdefinedin[8],Thes(A_n)hasbeenprovedin[6]tobeagoodpreconditionerinsolvingsymmetricToeplitzsystemswiththepreconditionedconjugategradient(PCG)method.Inthispaper,wediscussthealgebraicandgeometricpropertiesoftheoperators,andcomputeitsoperatornormsinBanachspacesofsymmetricmatrices.Somenumericaltestsandanapplicationinimagerestorationarealsogiven.
简介:InthepresentpaperweintroducearandomiterationschemeforthreerandomoperatorsdefinedonaclosedandconvexsubsetofauniformlyconvexBanachspaceandproveitsconvergencetoacommonfixedpointofthreerandomoperators.Theresultisalsoanextensionofaknowntheoreminthecorrespondingnon-randomcase.
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简介:AnewclassofalmostasymptoticallynonexpansivetypemappingsinBanachspacesisintroduced,whichincludesanumberofknownclassesofnonlinearLipschitzianmappingsandnon-LipschitzianmappingsinBanachspacesasspecialcases;forexample,theknownclassesofnonexpansivemappings,asymptoticallynonexpansivemappingsandasymptoticallynonexpansivetypemappings.TheconvergenceproblemofmodifiedIshikawaiterativesequenceswitherrorsforapproximatingfixedpointsofalmostasymptoticallynonexpansivetypemappingsisconsidered.NotonlyS.S.Chang'sinequalitybutalsoH.K.Xu'soneforthenormsofBanachspacesareappliedtomaketheerrorestimatebetweentheexactfixedpointandtheapproximateone.Moreover,ZhangShi-sheng'smethod(AppliedMathematicsandMechanics(EnglishEdition),2001,22(1):25-34)formakingtheconvergenceanalysisofmodifiedIshikawaiterativesequenceswitherrorsisextendedtothecaseofalmostasymptoticallynonexpansivetypemappings.ThenewconvergencecriteriaofmodifiedIshikawaiterativesequenceswitherrorsforfindingfixedpointsofalmostasymptoticallynonexpansivetypemappingsinuniformlyconvexBanachspacesarepresented.Also,thenewconvergencecriteriaofmodifiedManniterativesequenceswitherrorsforthisclassofmappingsareimmediatelyobtainedfromthesecriteria.Theaboveresultsunify,improveandgeneralizeZhangShi-sheng'sonesonapproximatingfixedpointsofasymptoticallynonexpansivetypemappingsbythemodifiedIshikawaandManniterativesequenceswitherrors.
简介:WestudytheboundedandthecompactweightedcompositionoperatorsfromtheBlochspaceintotheweightedBanachspacesofholomorphicfunctionsonboundedhomogeneousdomains,withparticularattentiontotheunitpolydisk.Forboundedhomogeneousdomains,wecharacterizetheboundedweightedcompositionoperatorsanddeterminetheoperatornorm.Inaddition,weprovidesufficientconditionsforcompactness.Fortheunitpolydisk,wecompletelycharacterizethecompactweightedcompositionoperators,aswellasprovide'computable'estimatesontheoperatornorm.
简介:Inthispaper,letKbeanonemptysubsetofauniformlysmoothBanachspaceX,andT:K→2~kbeamultivaluedoperatorofthemonotonetype.TheiterativesequencewhichconvergesstronglytotheuniquefixedpointofTisgiven.OurresultsaretheextensionandimprovementsoftheresultsobtainedpreviouslybyseveralauthorsincludingDunn,Chidume,DengandDing.
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简介:TheauthorsprovetheHyers-Ulam-RassiasstabilityofthequadraticmappinginBanachmodulesoveraunitalC*-algebra,andprovetheHyers-Ulam-RassiasstabilityofthequadraticmappinginBanachmodulesoveraunitalBanachalgebra.