一类无Lipschitz假设的非线性算子的带误差的Ishikawa迭代程序

１引言与预备知识 设Ｘ为一实赋范线性空间．Ｘ·是Ｘ的对偶空间,正规对偶映射Ｊ：Ｘ→２Ｘ定义为：其中＜·,·＞表示Ｘ和Ｘ的广义对偶组．由［１］知若Ｘ是一致光滑Ｂａｎａｃｈ空间,则Ｊ（·）单值且在Ｘ的任何有界子集上为一致连续．我们用ｊ（·）表示单值的正规对偶映射． 定义１［２］设Ｋ是Ｘ的一非空子集,算子Ｔ：Ｋ→Ｘ称为是　－强伪压缩的,如果存在一个严格增加函数　,存在使得 定义２［２,３］Ｔ称为　强增生算子的,如果（Ｉ－Ｔ）是　－强伪压缩算子（其中Ｉ是恒等算子）． 若定义１（相应地;定义２）中　（ｔ）＝ｋ…     

The equivalence between the convergence of Ishikawa and Mann iterations with errors for strongly successively pseudocontractive mappings without Lipschitzian assumption

In this paper we prove some new equivalences between convergence of the Ishikawa and Mann iteration sequences with errors in two schemes by Xu [Y.G. Xu, Ishikawa and Mann iteration process with errors for nonlinear strongly accretive operator equations, J. Math. Anal. Appl. 224 (1998) 91-101] and Liu [L.S. Liu, Ishikawa and Mann iterative process with errors for nonlinear strongly accretive mappings in Banach spaces, J. Math. Anal. Appl. 194 (1995) 114-125], respectively, for strongly successively pseudocontractive mappings. Our main results improve and extend the corresponding results of the all references listed in this article.     

q-致光滑Banach空间中非线性φ-强伪压缩映射和强增生映射的Ishikawa迭代过程

在q（≥2）一致光滑的实Banach空间中,研究了一类非Lipschitz,非值域有界的φ－强伪压缩映射和φ－强增生映射的Ishikawa迭代收敛问题,所得结果扩展了该领域目前所有的相关结果,因而在目前更具有一般性和广泛性．     

φ-强增生型变分包含的Ishikawa迭代序列强收敛的充要条件

研究Banach空间中φ-强增生型变分包含问题,在实的自反的光滑Banach空间中,证明了这类变分包含问题解得存在唯一性,并给出Ishikawa迭代序列{xn}强收敛的充要条件     

Equivalence theorems of the convergence between Ishikawa and Mann iterations with errors for generalized strongly successively Φ-pseudocontractive mappings without Lipschitzian assumptions

In this paper, the equivalence of the strong convergence between the modified Mann and Ishikawa iterations with errors in two different schemes by Xu [Y.G. Xu, Ishikawa and Mann iteration process with errors for nonlinear strongly accretive operator equations, J. Math. Anal. Appl. 224 (1998) 91-101] and Liu [L.S. Liu, Ishikawa and Mann iterative process with errors for nonlinear strongly accretive mappings in Banach spaces, J. Math. Anal. Appl. 194 (1995) 114-125] respectively is proven for the generalized strongly successively Φ-pseudocontractive mappings without Lipschitzian assumption. Our results generalize the recent results of the papers [Zhenyu Huang, F. Bu, The equivalence between the convergence of Ishikawa and Mann iterations with errors for strongly successively pseudocontractive mappings without Lipschitzian assumption, J. Math. Anal. Appl. 325 (1) (2007) 586-594; B.E. Rhoades, S.M. Soltuz, The equivalence between the convergences of Ishikawa and Mann iterations for an asymptotically nonexpansive in the intermediate sense and strongly successively pseudocontractive maps, J. Math. Anal. Appl. 289 (2004) 266-278; B.E. Rhoades, S.M. Soltuz, The equivalence between Mann-Ishikawa iterations and multi-step iteration, Nonlinear Anal. 58 (2004) 219-228] by extending to the most general class of the generalized strongly successively Φ-pseudocontractive mappings and hence improve the corresponding results of all the references given in this paper by providing the equivalence of convergence between all of these iteration schemes for any initial points u₁, x₁ in uniformly smooth Banach spaces.     

关于强伪压缩算子与强增生算子的Ishikawa型迭代序列收敛性的特征

本文结果表征了用于构造强增生算子方程解,m-增生算子方程解及强伪压缩算子不动点的(带误差的)Ishikawa型迭代序列的收敛性,推广与改进了Chidume与Osilike的定理1,定理2及定理3(Nonlinear Anal.TMA,1999,36(7):863-872)。     

Iterative Solutions of Nonlinear Equations of the Strongly Accretive Type

Let E be a real q-uniformly smooth Banach space. Suppose T is a strongly pseudo-contractive map with open domain D(T) in E. Suppose further that T has a fixed point in D(T). Under various continuity assumptions on T it is proved that each of the Mann iteration process or the Ishikawa iteration method converges strongly to the unique fixed point of T. Related results deal with iterative solutions of nonlinear operator equations involving strongly accretive maps. Explicit error estimates are also provided.     

Banach空间中多值Φ-增生和多值Φ-伪压缩映象的收敛定理

在任意Banach空间中引入比重要的多值-强增生映象和多值-强伪压缩映象更一般的多值Φ-增生映象和多值Φ-伪压缩映象,研究多值Φ-增生映象方程的解和多值Φ-伪压缩映象不动点的具随机误差的Ishikawa迭代逼近问题.这些结论推广和改进了最新文献中相应的结果.     

AN ITERATIVE PROCESS FOR FINDING APPROXIMATE SOLUTIONS TO NONLINEAR EQUATIONS OF STRONGLY ACCRETIVE OPERATORS

In this paper, we investigate the Ishikawa iteration process in a p-uniformly smooth Banach space X. We prove that the Ishikawa iteration process converges strongly to the unique solution of the equation Tx=f when T is a Lipschitzian and strongly accretive operator frow X to X, or to the unique fixed point of T when T is a Lipschitzian and strictly pseudocontractive mapping from a nonempty closed convex subset K of X into itself. Our results are the extension and improvements of the earlier and recent results in this field.     

Ishikawa iterative process with errors for nonlinear equations of generalized monotone type in Banach spaces

The concept of the operators of generalized monotone type is introduced and iterative approximation methods for a fixed point of such operators by the Ishikawa and Mann iteration schemes {xn} and {yn} with errors is studied. Let X be a real Banach space and T : D ? X → 2^D be a multi‐valued operator of generalized monotone type with fixed points. A new general lemma on the convergence of real sequences is proved and used to show that {xn} converges strongly to a unique fixed point of T in D. This result is applied to the iterative approximation method for solutions of nonlinear equations with generalized strongly accretive operators. Our results generalize many of know results. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The Equivalence of Ishikawa-Mann and Multistep Iterations in Banach Space

Let E be a real Banach space and T be a continuous Φ-strongly accretive operator. By using a new analytical method, it is proved that the convergence of Mann, Ishikawa and three-step iterations are equivalent to the convergence of multistep iteration. The results of this paper extend the results of Rhoades and Soltuz in some aspects.     

Banach空间中强增生算子的非线性方程的解的迭代构造

本文研究ｐ一致光滑Ｂａｎａｃｈ空间Ｘ中Ｉｓｈｉｋａｗａ迭代法．受Ｄｅｎｇ与Ｔａｎ，Ｘｕ的启发，证明了，当Ｔ是从Ｘ到自身的Ｌｉｐｓｃｈｉｔｚ强增生算子时，Ｉｓｈｉｋａｗａ迭代法强收敛到方程Ｔｘ＝ｆ的唯一解；当Ｔ是从Ｘ的有界闭凸子集到自身的Ｌｉｐｓｃｈｉｔｚ严格伪压缩映象时，Ｉｓｈｉｋａｗａ迭代法强收敛到Ｔ的唯一不动点．通过去掉限制ｌｉｍ_ｎ→∞β_ｎ＝０或ｌｉｍ_ｎ→∞α_ｎ＝ｌｉｍ_ｎ→∞β_ｎ＝０，结果改进与推广了Ｔａｎ，Ｘｕ的定理４．１与定理４．２，也把Ｄｅｎｇ的定理１与定理２推广到了ｐ一致光滑Ｂａｎａｃｈ空间的背景．     

关于增生算子方程解的带误差的Ishikawa迭代程序

该文在Banach空间中证明了，带误差的Ishikawa迭代序列强收敛到Lipschitz连续的增生算子方程的唯一解．而且，也给Ishikawa迭代序列提供了一般的收敛率估计．利用该结果还推得，带误差的Ishikawa迭代序列也强收敛到Lipschitz连续的强增生算子方程的唯一解．     

Three-step iterations for nonlinear accretive operator equations

In this paper, we suggest and analyze a three-step iterative scheme for solving nonlinear strongly accretive operator equation Tx=f without continuous condition in a uniformly smooth Banach space. Our results include the Ishikawa, Mann and Noor iterations as special cases. The results presented in this paper improve and extend almost all the current results in the more general setting.     

Banach空间中的非线性增生算子随机方程

本文引进（ＪＭ）型算子的概念，并证明非线性增生算子和（ＪＭ）型算子随机方程的解的存在定理。     

一类具有广义Lipschitz条件的非线性映象的迭代过程

本文研究了广义Ｌｉｐｓｃｈｉｔｚ强增生映象的Ｉｓｈｉｋａｗａ型迭代和Ｍａｎｎ型迭代过程的收敛性．所得结果统一和扩展了近期相关结果     

相对φ强伪压缩算子不动点的迭代逼近

在没有任何有界以及迭代参数列不必收敛于零等条件下,使用新的分析方法建立了相对φ强伪压缩算子不动点与相对φ强增生算子方程解具误差Ishikawa迭代序列的强收敛定理,推广和改进了有关文献中的相应结果,而且还给出了收敛率的估计式.     

关于增生算子方程的具误差的Ishikawa迭代序列的收敛率估计

设X是一实的Banach空间,TLX→X是—Lipschitz的增生算子;证明了具误差的Ishikawa迭代序列强收敛到x＋Tx=f的唯一解;得到一个一般的收敛率估计式．进一步得到：若了T：X→X是—Lipschitz的强增生算子,则具误差的Ishikawa迭代序列强收敛到Tx=f的唯一解．文中结果推广和发展了已有的相关结果．     

Weak stability of the Ishikawa iteration procedures for -hemicontractions and accretive operators

Let X be an arbitrary Banach space, K be a nonempty closed convex subset of X, and T : K → K be a Lipschitzian and hemicontractive mapping with the property lim inf_t→∞((t)/t) > 0. It is shown that the Ishikawa iteration procedures are weakly T-stable. As consequences, several related results deal with the weak stability of these procedures for the iteration proximation of solutions of nonlinear equations involving accretive operators. Our results improve and extend those corresponding results announced by Osilike.     

含k-次增生算子的Ishikawa迭代的收敛性问题

主要研究了非线性方程x Tx=f的Ishikawa迭代解．其中T为k-次增生的或增生的，并在一致光滑和任意的实Banach空间分别研究了上述方程的带误差的Ishikawa迭代解，从而推广了已知的一些结果。