求解单调变分不等式问题的一个连续型迭代方法

本文给出一个求解单调变分不等式问题的连续型迭代方法,对任意单调趋于零的正数序列和任意初始点,方法产生的迭代点列均收敛到所求变分不等式问题的一个解,且在适当条件下方法具有Q-超线性收敛率.数值试验结果进一步表明了所给方法的稳定性和有效性.     

On Global Convergence and Approximate Iteration of the Linear Approximation Method for Solving Variational Inequalities

This paper is concerned with the linear approximation method (i.e. the iterative method in which a sequence of vectors is generated by solving certain linearized subproblems) for solving the variational inequality. The global convergent iterative process is proposed by applying the continuation method, and the related problems are discussed. A convergent result is obtained for the approximation iteration (i.e. the iterative method in which a sequence of vectors is generated by solving certain linearized subproblems approximately).     

A block monotone iterative method for numerical solutions of nonlinear elliptic boundary value problems

The aim of this article is to develop a new block monotone iterative method for the numerical solutions of a nonlinear elliptic boundary value problem. The boundary value problem is discretized into a system of nonlinear algebraic equations, and a block monotone iterative method is established for the system using an upper solution or a lower solution as the initial iteration. The sequence of iterations can be computed in a parallel fashion and converge monotonically to a maximal solution or a minimal solution of the system. Three theoretical comparison results are given for the sequences from the proposed method and the block Jacobi monotone iterative method. The comparison results show that the sequence from the proposed method converges faster than the corresponding sequence given by the block Jacobi monotone iterative method. A simple and easily verified condition is obtained to guarantee a geometric convergence of the block monotone iterations. The numerical results demonstrate advantages of this new approach. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011     

一种生成迭代数列的新方法

围绕两个典型迭代数列的构造问题,以问题为驱动,提出一种生成迭代数列的新方法,并通过数值实验或理论证明验证迭代数列的收敛性.     

Φ-伪压缩映象带混合型误差的迭代序列的强稳定性

引入带混合型误差的 Ishikawa和 Mann迭代序列 ,在没有 D是有界闭集与多值映象 T是一致连续的较弱条件下 ,在实 Banach空间中研究了多值Φ -伪压缩映象不动点的带混合型误差的 Ishikawa和 Mann迭代序列的逼近问题 ,使用与文献完全不同的方法 ,建立了带混合型误差的 Ishikawa和 Mann迭代序列的强稳定性定理 ,从而统一和发展了几位作者早期与最近的相关结果 .     

A convergence analysis of nonlinear implicit iterative method for nonlinear ill-posed problems

Implicit iterative method acquires good effect in solving linear ill-posed problems. We have ever applied the idea of implicit iterative method to solve nonlinear ill-posed problems, under the restriction that α is appropriate large, we proved the monotonicity of iterative error and obtained the convergence and stability of iterative sequence, numerical results show that the implicit iterative method for nonlinear ill-posed problems is efficient. In this paper, we analyze the convergence and stability of the corresponding nonlinear implicit iterative method when α_k are determined by Hanke criterion.     

On relaxed viscosity iterative methods for variational inequalities in Banach spaces

In this paper, we suggest and analyze a relaxed viscosity iterative method for a commutative family of nonexpansive self-mappings defined on a nonempty closed convex subset of a reflexive Banach space. We prove that the sequence of approximate solutions generated by the proposed iterative algorithm converges strongly to a solution of a variational inequality. Our relaxed viscosity iterative method is an extension and variant form of the original viscosity iterative method. The results of this paper can be viewed as an improvement and generalization of the previously known results that have appeared in the literature.     

非扩张映射不动点的粘性逼近方法

在具有一致Gateaux可微范数的Banach空间中,建立了一个改进的非扩张映射不动点的粘性逼近方法,并在一定条件下证明了该方法所得到的迭代序列的强收性.本文所得结果扩展并统一了部分文献的结果.     

Monotone Convergence of Iterative Methods for Singular Linear Systems

In this paper, monotonicity of iterative methods for solving general solvable singularly systems is discussed. The monotonicity results given by Berman, Plemmons, and Semal are generalized to singular systems. It is shown that for an iterative method introduced by a nonnegative splitting of the coefficient matrix there exist some initial guesses such that the iterative sequence converges towards a solution of the system from below or from above. The monotonicity of the block Gauss-Seidel method for solving a p-cyclic system and Markov chain is considered.     

无穷区间上一类分数阶微分方程正解的显式迭代序列

By applying the monotone iterative method,this study develops two explicit monotone iterative sequences for approximating the minimal and maximal positive solutions.At the same time,by applying the Banach fixed-point theory,an explicit iterative sequence and error estimate for approximating the unique positive solution is obtained.Some examples are given to illustrate the application of the results.     

递推数列x_(n+1)=f(x_n)的单调性与收敛性讨论

利用函数单调递增对递推数列xn+1=f(xn)单调性进行讨论,在对递推数列收敛性作分析的基础上,得到使得递推数列收敛的初始迭代值的区域,讨论的方法可以用于类似问题的研究.     

递推数列xn＋1=f（xn）的单调性与收敛性讨论

利用函数单调递增对递推数列xn＋1=f（xn）单调性进行讨论,在对递推数列收敛性作分析的基础上,得到使得递推数列收敛的初始迭代值的区域,讨论的方法可以用于类似问题的研究．     

Algorithms for Unconstrained Optimization Problems via Control Theory

Existing algorithms for solving unconstrained optimization problems are generally only optimal in the short term. It is desirable to have algorithms which are long-term optimal. To achieve this, the problem of computing the minimum point of an unconstrained function is formulated as a sequence of optimal control problems. Some qualitative results are obtained from the optimal control analysis. These qualitative results are then used to construct a theoretical iterative method and a new continuous-time method for computing the minimum point of a nonlinear unconstrained function. New iterative algorithms which approximate the theoretical iterative method and the proposed continuous-time method are then established. For convergence analysis, it is useful to note that the numerical solution of an unconstrained optimization problem is none other than an inverse Lyapunov function problem. Convergence conditions for the proposed continuous-time method and iterative algorithms are established by using the Lyapunov function theorem.     

A generalized preconditioned HSS method for non-Hermitian positive definite linear systems

Based on the HSS (Hermitian and skew-Hermitian splitting) and preconditioned HSS methods, we will present a generalized preconditioned HSS method for the large sparse non-Hermitian positive definite linear system. Our method is essentially a two-parameter iteration which can extend the possibility to optimize the iterative process. The iterative sequence produced by our generalized preconditioned HSS method can be proven to be convergent to the unique solution of the linear system. An exact parameter region of convergence for the method is strictly proved. A minimum value for the upper bound of the iterative spectrum is derived, which is relevant to the eigensystem of the products formed by inverse preconditioner and splitting. An efficient preconditioner based on incremental unknowns is presented for the actual implementation of the new method. The optimality and efficiency are effectively testified by some comparisons with numerical results.     

Existence and uniqueness of positive solutions for singular nonlinear elliptic boundary value problems

In this paper we establish the existence and the uniqueness of positive solutions for Dirichlet boundary value problems of nonlinear elliptic equations with singularity. We obtain the existence and the uniqueness by using the mixed monotone method in the cone theory. Moreover, we give an iterative method of constructing the solution. The rate of convergence of the iterative sequence is analyzed.     

Regularization in the Mosolov and Myasnikov problem with boundary friction

We propose an iterative algorithm for solving a semicoercive nonsmooth variational inequality. The algorithm is based on the stepwise partial smoothing of the minimized functional and an iterative proximal regularization method.We obtain a solution to the variational Mosolov and Myasnikov problem with boundary friction as a limit point of a sequence of solutions to stable auxiliary problems.     

A necessary and sufficient condition for the strong convergence of Lipschitzian pseudocontractive mapping in Banach spaces

The purpose of this paper is to establish some necessary and sufficient conditions for the strong convergence of the Ishikawa iterative sequence and the Mann iterative sequence to a fixed point of pseudocontractive mapping in Banach spaces. Our results, to some extent, improve and extend the well-known result of [S. Ishikawa, Fixed points by a new iteration method, Proc. Amer. Math. Soc. 44(1) (1974) 147–150.] to Banach spaces.     

Asymptotic properties of a stochastic predator-prey model with Crowley-Martin functional response

A two-step iterative scheme based on the multiplicative splitting iteration is presented for PageRank computation. The new algorithm is applied to the linear system formulation of the problem. Our method is essentially a two-parameter iteration which can extend the possibility to optimize the iterative process. Theoretical analyses show that the iterative sequence produced by our method is convergent to the unique solution of the linear system, i.e., PageRank vector. An exact parameter region of convergence for the method is strictly proved. In each iteration, the proposed method requires solving two linear sub-systems with the splitting of the coefficient matrix of the problem. We consider using inner iterations to compute approximate solutions of these linear sub-systems. Numerical examples are presented to illustrate the efficiency of the new algorithm.     

An extragradient-type method for generalized equilibrium problems involving strictly pseudocontractive mappings

In this paper, an extragradient-type method is introduced for finding a common element in the solution set of generalized equilibrium problems, in the solution set of classical variational inequalities and in the fixed point set of strictly pseudocontractive mappings. It is proved that the iterative sequence generated in the purposed extragradient-type iterative process converges weakly to some common element in real Hilbert spaces.     

Mann-Type Steepest-Descent and Modified Hybrid Steepest-Descent Methods for Variational Inequalities in Banach Spaces

In this paper, we propose three different kinds of iteration schemes to compute the approximate solutions of variational inequalities in the setting of Banach spaces. First, we suggest Mann-type steepest-descent iterative algorithm, which is based on two well-known methods: Mann iterative method and steepest-descent method. Second, we introduce modified hybrid steepest-descent iterative algorithm. Third, we propose modified hybrid steepest-descent iterative algorithm by using the resolvent operator. For the first two cases, we prove the convergence of sequences generated by the proposed algorithms to a solution of a variational inequality in the setting of Banach spaces. For the third case, we prove the convergence of the iterative sequence generated by the proposed algorithm to a zero of an operator, which is also a solution of a variational inequality.