无限族demi压缩映射与平衡问题的收敛定理

在Hilbert空间中,为了找到无限个demi压缩映射公共不动点集和广义混合平衡问题解的公共元,本文介绍了一种迭代算法,得到关于公共元的强收敛定理,并给出例子说明结果.     

Hilbert空间框架下严格渐近伪压缩映像的强收敛定理

The Mann iterations have no strong convergence even for nonexpansive mappings in Hilbert spaces. The aim of this paper is to propose a modification of the Mann iterations for strictly asymptotically pseudocontractive maps in Hilbert spaces to have strong convergence. Our results extend those of Kim, Xu, Nakajo, Takahashi and many others.     

Banach空间中Lipschitz伪压缩映射的近似不动点序列及其收敛定理

研究了Lipschitz伪压缩映射的黏滞迭代方法.设E为一致光滑Bannach空间,K为E的闭凸子集,TK→K为Lipschitz伪压缩映射且其不动点集F(T)非空,f为K上的压缩映射且t∈(0,1).若黏滞迭代路径{xt},xt=(1-t)f(xt) tTxt且对任意初始向量x1∈K,迭代序列{xn}定义为xn 1=λnθnf(xn) [1-λn(1 θn)]xn λnTxn,则当t→1-和n→∞时,{xt}和{xn}都强收敛于T的不动点,同时该不动点还是一类变分不等式的解.     

用Ishikawa迭代程序逼近严格伪压缩映射的不动点

本文证明了定义在Banach空间X中闭凸子集K上的Lipschitz严格伪压缩 映射T的不动点,可由Ishilkawa迭代程序逼近,并给出了更一般的收敛率的估计,从而 统一和发展了近期的一些有关的结果.     

Banach空间中严格渐近伪压缩映象的收敛性问题

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．     

严格伪压缩映象的复合隐格式迭代序列的收敛率估计

设K是实Banach空间E的非空闭凸集,{Ti}iN=1:K→K是N个严格伪压缩映象且公共不动集F=∩Ni=1F(Ti)≠φ,其中F(Ti)={x∈K:Tix=x}.{αn}n∞=1,{βn}n∞=1[0,1]是实序列且满足条件:(i)sum from n=1 to ∞ (αn)(ii)lim(n→∞)αn=lim(n→∞)βn=0(iii)αnβnL2<1,n≥1其中L≥1是{Ti}iN=1的公共Lipschitz常数.对于任意的x0∈K,设{xn}n∞=1是由下列产生的复合隐格式迭代序列:xn=(1-αn)xn-1+αn Tnynyn=(1-βn)xn-1+βnTnxn其中Tn=Tn mod N,则{xn}强收敛到{Ti}iN=1的公共不动点.结果推广和改进了相关文献的结果,且主要定理的证明方法也是不同的.并且进一步给出了序列的收敛率估计.     

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.     

Lipschitz局部严格伪压缩映象的迭代逼近

设Ｋ是一致光滑Ｂａｎａｃｈ空间Ｋ的非空子集，Ｔ：Ｋ→Ｘ是Ｌｉｐｓｃｈｉｔｚ局部严格伪压缩映象。本文给出一个迭代序列强收敛到Ｔ的唯一不动点，并给出一个涉及Ｌｉｐｓｃｈｉｔｚ局部强增殖映象Ｔ的非线性方程Ｔｘ＝ｆ的解的迭代逼近。     

Weak and Strong Convergence Theorems for New Demimetric Mappings and the Split Common Fixed Point Problem in Banach Spaces

In this paper, we consider the split common fixed point problem for new demimetric mappings in Banach spaces. Using the idea of Mann’s iteration, we prove a weak convergence theorem for finding a solution of the split common fixed point problem in Banach spaces. Furthermore, using the idea of Halpern’s iteration, we obtain a strong convergence theorem for finding a solution of the problem in Banach spaces. Using these results, we obtain well-known and new weak and strong convergence theorems in Hilbert spaces and Banach spaces.     

连续伪压缩映射的黏滞迭代逼近方法

设K是实自反Banach空间E的一个闭凸子集,T：K→K是一个连续伪压缩映射,f：K→K是一个固定的L-Lipschitzian强伪压缩映射．对于任意的t∈(0,1),设x_t是tf+(1-t)T的唯一不动点．我们证明了如果T有不动点且有从E到E~*弱序列连续对偶映像,则当t趋于0时,{x_t}收敛于T的一个不动点．这个结果改进和推广了文[4]的相应结果．     

Strong Convergence of a Split Common Fixed Point Problem

In this article, we present a new general algorithm for solving the split common fixed point problem in an infinite dimensional Hilbert space, which is to find a point which belongs to the common fixed point of a family of quasi-nonexpansive mappings such that its image under a linear transformation belongs to the common fixed point of another family of quasi-nonexpansive mappings in the image space. We establish the strong convergence for the algorithm to find a unique solution of the variational inequality, which is the optimality condition for the minimization problem. The algorithm and its convergence results improve and develop previous results in this field.     

Optimization for Inconsistent Split Feasibility Problems

The split feasibility problem deals with finding a point in a closed convex subset of the domain space of a linear operator such that the image of the point under the linear operator is in a prescribed closed convex subset of the image space. The split feasibility problem and its variants and generalizations have been widely investigated as a means for resolving practical inverse problems in various disciplines. Many iterative algorithms have been proposed for solving the problem. This article discusses a split feasibility problem which does not have a solution, referred to as an inconsistent split feasibility problem. When the closed convex set of the domain space is the absolute set and the closed convex set of the image space is the subsidiary set, it would be reasonable to formulate a compromise solution of the inconsistent split feasibility problem by using a point in the absolute set such that its image of the linear operator is closest to the subsidiary set in terms of the norm. We show that the problem of finding the compromise solution can be expressed as a convex minimization problem over the fixed point set of a nonexpansive mapping and propose an iterative algorithm, with three-term conjugate gradient directions, for solving the minimization problem.     

Banach空间中一致L-Lipschitz映象的强收敛定理

在任意实Banach空间中引入了一对一致L-Lipschitz映象的具误差的新迭代序列,并证明了这些迭代序列的强收敛性定理.结果推广、完善和改进了最近的一些结果.     

关于包含有限个强伪压缩映射的凸可行性问题解的迭代逼近

在Banach空间中,证明了多步迭代序列强收敛于有限个强伪压缩映射的公共不动点.同时,给出了有限个(强)增生算子方程公共解的强收敛定理.所得结果推广和改进了许多重要结果.     

A Successive Projection Algorithm for Solving the Multiple-Sets Split Feasibility Problem

The multiple-sets split feasibility problem (MSFP) arises in many areas and it can be unified as a model for many inverse problems where the constraints are required on the solutions in the domain of a linear operator as well as in the operator's range. Some existing algorithms, in order to get the suitable step size, need to compute the largest eigenvalue of the related matrix, estimate the Lipschitz constant, or use some step-size search scheme, which usually requires many inner iterations. In this article, we introduce a successive projection algorithm for solving the multiple-sets split feasibility problem. In each iteration of this algorithm, the step size is directly computed, which is not needed to compute the largest eigenvalue of the matrix or estimate the Lipschitz constant. It also does not need any step-size search scheme. Its theoretical convergence results are also given.     

Hilbert空间中广义平衡问题和无限族非扩张映象的不动点问题的强收敛定理

在Hilbert空间中,用Fan-KKM定理导出了广义平衡问题的辅助问题的解的存在性和唯一性,讨论了寻找广义平衡问题和一族非扩张映象的公共不动点集的迭代序列,证明此序列强收敛于这两个集合的公共元.本文结论改进了一些近期结果.     

Novel Hybrid Methods for Pseudomonotone Equilibrium Problems and Common Fixed Point Problems

The purpose of this article is to introduce some hybrid algorithms for finding a common element of the solution sets of pseudomonotone equilibrium problems and the fixed point sets of nonexpansive mappings in real Hilbert spaces. Our algorithms combine Mann’s iterative methods and Armijo line-search with parallel splitting-up and hybrid techniques. The strong convergence of the proposed algorithms are established without the assumption on the Lipschitz-type condition for the bifunctions involved.     

Strong Convergence Theorems for Quasi-Nonexpansive Mappings and Uniformly L-Lipschitzian Asymptotically Pseudo-Contractive Mappings in Banach Spaces

A new 𝒮-generated Ishikawa iteration with errors is proposed for a pair of quasi-nonexpansive mapping and uniformly L-Lipschitzian asymptotically pseudo-contractive mapping in real Banach spaces. We show that the proposed iterative scheme converges strongly to a common solution of quasi-nonexpansive mapping and uniformly L-Lipschitzian asymptotically pseudo-contractive mapping in real Banach spaces. A comparison table is prepared using a numeric example which shows that the proposed iterative algorithm is faster than some known iterative algorithms.     

平衡问题解的存在性

主要研究平衡问题解的存在性.通过对目标函数和可行集合的渐近分析,给出拟单调平衡问题解集非空的条件.进而用类似的方法研究了向量平衡问题解存在的条件,并将其应用到向量优化问题上.