迭代序列逼近非线性映像不动点集的一个几何结构

设E是Hilbert空间,T：D(T)→R(T)是E中具非空不动点集F(T)的非线性映像,许多非线性映像的多种形式的迭代序列{X_n}可逼近映像T的不动点p0∈F(T),并且逼近过程{X_n}与不动点集F(T)有密切的几何关系,其中一种几何关系可描述为钝角原理,其准确表述为lim sup_n→+∞〈p—p0,■〉■0,■p∈F(T)．或令θ_n(p)=arccos〈■〉,■p∈F(T)．钝角原理可表述为liminf_n→+∞θ_n(p)■π/2．在相应条件下,具有这种几何关系的非线性映像包括非扩张映像、渐近非扩张映像、Lipschitz映像、增生映像、伪压缩映像、渐近伪压缩映像、严格伪压缩映像、强伪压缩映像等大量非线性映像．钝角原理一方面可揭示非线性映像不动点逼近过程的几何结构,也是迭代逼近非线性映像不动点的必要条件．     

Banach空间中关于变分不等式组与严格伪压缩映射的粘滞逼近法

本文利用粘滞逼近法建立了一迭代序列来逼近两个集合的公共元素,这两个集合分别是Banach空间中广义变分不等式组的解集与Banach空间中有限个严格伪压缩映射的公共不动点集.本文证明了该迭代序列强收敛到这两个集合的某一公共元素,且该元素为某一变分不等式的解.本文的结果提高与推广了许多相关结论.     

有限族严格伪压缩映象具误差的隐迭代序列的强收敛性

在适当的条件下,证明了有限族严格伪压缩映象具误差的隐迭代序列强收敛于其公共不动点. 所得结果改进了Osilike 与 Xu, Ori 的相应结果.     

严格拟伪压缩映像族的复合迭代算法

在Hilbert空间中设计了一种关于严格拟伪压缩映像族的复合迭代算法,并利用度量投影法证明了严格拟伪压缩映像族的公共不动点的强收敛定理,所得结果改进和推广了一些最新文献的相关结果.     

Banach空间中可数非扩张映像族公共不动点迭代算法

提出一种新的迭代算法用于求解实一致光滑Banach空间上可数非扩张映像族的公共不动点.在一定条件下证明了迭代算法产生的序列强收敛到一个公共不动点,并且此不动点也是一个变分不等式的解.此结果改进和推广了已有的相关结果.     

Banach空间中关于变分不等式组与严格伪压缩映射的广义迭代法(英文)

本文利用广义迭代法建立一迭代序列,通过该序列讨论Banach空间中一类广义变分不等式组的解与有限个严格伪压缩映射的公共不动点,并且得到该序列的强收敛性.本文所得结论推广和提高了以前一些相应结果.     

扩展到无弱序列连续对偶映射Banach空间的关于变分包含与不动点问题的广义迭代算法

该文根据广义迭代算法在无弱序列连续对偶映射的q-一致光滑的Banach空间引进了一迭代序列来寻找两个集合的公共元素,这两个集合分别是包含两个H-增生映射的一类非线性变分包含组的解集和一无限族严格伪压缩映射的公共不动点集.该迭代序列得到的这一公共元素还是某一变分不等式的唯一解.该文提高和扩展了一些相关结果.     

Hilbert空间中Lipschitz单调映像变分不等式解的另一个逼近定理

首先给出了Hilbert空间中Lipschitz单调映像变分不等式解的迭代格式,并证明了其收敛性.作为应用,证明了Hilbert空间中Lipschitz伪压缩映像的强收敛定理,扩展了已知的相关结果.     

均衡问题和不动点问题的粘滞近似方法及其应用

用粘滞近似方法产生了一个新的迭代序列,并证明了该迭代序列强收敛于一个非扩张映射的不动点,同时该不动点也是一个变分不等式和一个均衡问题的共同解.作为应用,另外证明了一个关于非扩张映射和严格伪压缩映射的定理.     

关于非扩张映象的最近的公共不动点问题

利用粘性逼近方法,在自反Banach空间的框架下,研究无限族非扩张映象及对给定的压缩映象的迭代程序的收敛性问题．在适当的条件下,证明了该迭代序列强收敛于某一公共不动点,而且这一公共不动点也是自反Banach空间中某一变分不等式的唯一解．所得结果改进和推广了一些人的最新的结果．     

无限族严格渐近伪压缩映象隐迭代程序的强收敛定理

在Banach空间框架下,对无限族的严格渐近伪压缩映象和无限族的非扩张映象引入了一类新的隐迭代程序,并在适当的条件下,证明了该迭代程序强收敛于这两族映象的公共不动点.结果是新的,它推广和改进了一些人的最新结果.     

Weak and strong convergence theorems of an implicit iteration for a countable family of continuous pseudocontractive mappings

To approximate a common fixed point of a countable family of continuous pseudocontractive mappings, we introduce an implicit iteration sequence. A necessary and sufficient condition for the convergence of a sequence of such iterates for countably many continuous pseudocontractive mappings is given. We also prove the convergence theorems of an implicit iteration sequence for a countable family of strictly pseudocontractive mappings.     

Convergence of the new composite implicit iteration process with random errors

In this paper, strong convergence theorems for approximation of common fixed points of a finite family of asymptotically demicontractive mappings are proved in Banach spaces using the new composite implicit iteration scheme with errors. Our results of this paper improve and extend the corresponding results of Chen, Song, Zhou [R.D. Chen, Y.S. Song, H.Y. Zhou, Convergence theorems for implicit iteration process for a finite family of continuous pseudocontractive mappings, J. Math. Anal. Appl. 314 (2006) 701–709], Osilike [M.O. Osilike, Implicit iteration process for common fixed points of a finite family of strictly pseudocontractive maps, J. Math. Anal. Appl. 294 (2004) 73–81], Gu [F. Gu, The new composite implicit iterative process with errors for common fixed points of a finite family of strictly pseudocontractive mappings, J. Math. Anal. Appl. 329 (2007) 766–776] and Yang and Hu [L.P. Yang, G. Hu, Convergence of implicit iteration process with random errors, Acta Math. Sinica (Chin. Ser.) 51 (1) (2008) 11–22].     

The new composite implicit iterative process with errors for common fixed points of a finite family of strictly pseudocontractive mappings

Convergence theorems for approximation of common fixed points of strictly pseudocontractive mappings of Browder-Petryshyn type are proved in Banach spaces using a new composite implicit iteration scheme with errors. The results presented in this paper generalize and improve the corresponding results of M.O. Osilike [M.O. Osilike, Implicit iteration process for common fixed points of a finite family of strictly pseudocontractive maps, J. Math. Anal. Appl. 294 (2004) 73-81].     

Convergence theorems for implicit iteration process for a finite family of continuous pseudocontractive mappings

In this paper, a necessary and sufficient conditions for the strong convergence to a common fixed point of a finite family of continuous pseudocontractive mappings are proved in an arbitrary real Banach space using an implicit iteration scheme recently introduced by Xu and Ori [H.K. Xu, R.G. Ori, An implicit iteration process for nonexpansive mappings, Numer. Fuct. Anal. Optim. 22 (2001) 767-773] in condition αn∈(0,1], and also strong and weak convergence theorem of a finite family of strictly pseudocontractive mappings of Browder-Petryshyn type is obtained. The results presented extend and improve the corresponding results of M.O. Osilike [M.O. Osilike, Implicit iteration process for common fixed points of a finite family of strictly pseudocontractive maps, J. Math. Anal. Appl. 294 (2004) 73-81].     

Regularized and inertial algorithms for common fixed points of nonlinear operators

This paper deals with a general fixed point iteration for computing a point in some nonempty closed and convex solution set included in the common fixed point set of a sequence of mappings on a real Hilbert space. The proposed method combines two strategies: viscosity approximations (regularization) and inertial type extrapolation. The first strategy is known to ensure the strong convergence of some successive approximation methods, while the second one is intended to speed up the convergence process. Under classical conditions on the operators and the parameters, we prove that the sequence of iterates generated by our scheme converges strongly to the element of minimal norm in the solution set. This algorithm works, for instance, for approximating common fixed points of infinite families of demicontractive mappings, including the classes of quasi-nonexpansive operators and strictly pseudocontractive ones.     

Convergence theorems of common fixed points for a finite family of Lipschitz pseudocontractions in Banach spaces

In this paper, we continue to study weak convergence problems for the implicit iteration process for a finite family of Lipschitzian continuous pseudocontractions in general Banach spaces. The results presented in this paper improve and extend the corresponding ones of Xu and Ori [H.K. Xu, R.G. Ori, An implicit iteration process for nonexpansive mappings, Numer. Funct. Anal. Optim. 22 (2001) 767–773], Osilike [M.O. Osilike, Implicit iteration process for common fixed points of a finite family of strictly pseudocontractive maps, J. Math. Anal. Appl. 294 (2004) 73–81], Chen et al. [R. Chen, Y.S. Song, H.Y. Zhou, Convergence theorems for implicit iteration process for a finite family of continuous pseudocontractive mappings, J. Math. Anal. Appl. 314 (2006) 701–709] and others.     

Implicit iteration process for common fixed points of a finite family of strictly pseudocontractive maps

Convergence theorems for approximation of common fixed points of strictly pseudocontractive mappings of Browder-Petryshyn type are proved in Banach spaces using an implicit iteration scheme recently introduced by Xu and Ori [Numer. Funct. Anal. Optim. 22 (2001) 767-773].     

严格渐近伪压缩映象隐迭代序列的收敛性

含有非扩张型映射的非线性算子方程的隐式迭代法,从2001年由H.K.Xu和R.G.Ori引入以来,已有许多学者进行了研究,得出了一些有意义的成果.最近M.O.Osilike对Browder-Petyshyn意义下的严格伪压缩映象的隐迭代过程,也做出了部分研究成果,但对严格渐近伪压缩映象未曾涉及.本文将主要研究Browder-Petyshyn意义下的严格渐近伪压缩映象的隐迭代过程.并讨论它们的收敛性问题.