Existence and Uniqueness of Viscosity Solutions for Nonlinear Variational Inequalities Associated with Mixed Control

The author investigates the nonlinear parabolic variational inequality derived from the mixed stochastic control problem on finite horizon. Supposing that some sufficiently smooth conditions hold, by the dynamic programming principle, the author builds the Hamilton-Jacobi-Bellman(HJB for short) variational inequality for the value function.The author also proves that the value function is the unique viscosity solution of the HJB variational inequality and gives an application to the quasi-variat...     

Variational Inequalities for Leavable Bounded-Velocity Control

We study the variational inequality associated with a bounded-velocity control problem when discretionary stopping is allowed. We establish the existence of a strong solution by using the viscosity solution techniques. The optimal policy is shown to exist from the optimality conditions in the variational inequality.     

Variational Inequalities for Leavable Bounded-Velocity Control

We study the variational inequality associated with a bounded-velocity control problem when discretionary stopping is allowed. We establish the existence of a strong solution by using the viscosity solution techniques. The optimal policy is shown to exist from the optimality conditions in the variational inequality.     

A Class of Combined Relaxation Methods for Decomposable Variational Inequalities

Combined relaxation methods are convergent to a solution of variational inequality problems under rather mild assumptions and admit various auxiliary procedures within their two-level structure. In this work, we consider ways to construct decomposition schemes within one class of combined relaxation methods, which maintain useful convergence properties. An application to primal-dual variational inequality problems is also given.     

A Combined Relaxation Method for a Class of Nonlinear Variational Inequalities

In this paper, we describe a class of combined relaxation methods for the non strictly monotone nonlinear variational inequality problem, which involves a max-type convex function. This method is readily implementable and attains a linear rate of convergence under certain additional assumptions.     

The Compression Property for Affine Variational Inequalities

In 1965, Gale and Nikaidô showed that for any n × n P-matrix A, the only nonnegative vector that A sends into a nonpositive vector is the origin. They applied that result to derive various results including univalence properties of certain nonlinear functions. In this article, we show that an extension of their result holds with the nonnegative orthant replaced by any nonempty polyhedral convex cone. In place of the P-matrix condition, we require a determinantal condition that we call the compression property. When the polyhedral convex cone is the nonnegative orthant, the compression property reduces to the property of being a P-matrix and we recover the Gale-Nikaidô result. We apply the extended theorem to derive tools useful in the analysis of affine variational inequalities over polyhedral convex cones.     

An LQP Method for Pseudomonotone Variational Inequalities

In this paper, we proposed a modified Logarithmic-Quadratic Proximal (LQP) method [Auslender et al.: Comput. Optim. Appl. 12, 31–40 (1999)] for solving variational inequalities problems. We solved the problem approximately, with constructive accuracy criterion. We show that the method is globally convergence under that the operator is pseudomonotone which is weaker than the monotonicity and the solution set is nonempty. Some preliminary computational results are given.The author was supported by the NSFC grants Nos: 70571033 and 10571083.     

非单调变分不等式黄金分割算法研究

该文考虑变分不等式的梯度投影算法,给出了一种非单调变分不等式的黄金分割算法,所给出的算法特点结合了惯性加速方法,无需知道映射的Lipschitz常数,且步长是非单调递减的.在一定的条件下,算法的收敛性被证明.最后给出数值实验结果.     

多值单调映象的Browder-Hartman-Stampacchia型变分不等式

在Ｂａｎａｃｈ空间中,证明了多值单调映象的Ｂｒｏｗｄｅｒ－Ｈａｒｔｍａｎ－Ｓｔａｍｐａｃｃｈｉａ型变分不等式解的存在性定理,统一并推广了「４,５,６,９」中的主要结果。     

Homotopy Methods for Solving Variational Inequalities in Unbounded Sets

In this paper, for solving the finite-dimensional variational inequality problem

A Connection between Singular Stochastic Control and Optimal Stopping

We show that the value function of a singular stochastic control problem is equal to the integral of the value function of an associated optimal stopping problem. The connection is proved for a general class of diffusions using the method of viscosity solutions.     

A Connection between Singular Stochastic Control and Optimal Stopping

We show that the value function of a singular stochastic control problem is equal to the integral of the value function of an associated optimal stopping problem. The connection is proved for a general class of diffusions using the method of viscosity solutions.     

A Goldstein's Type Projection Method for a Class of Variant Variational Inequalities

Some optimization problems in mathematical programming can be translated to a variant variational inequality of the following form: Find a vector $\u^*$,such that $$Q(u^*)∈Ω,(v-Q(u^*))^Tu^* ≥ 0, ∀_v∈Ω.$$. This paper presents a simple iterative method for solving this class of variational inequalities. The method can be viewed as an extension of the Goldstein's projection method. Some results of preliminary numerical experiments are given to indicate its applications.     

求解变分不等式的一种外逼近法的若干收敛性结果

本文讨论由文［１］提出的一种求解变分不等式问题的外逼近法,并在较弱条件下证明了该算法的收敛性     

Modified Extragradient Method for Variational Inequalities and Verification of Solution Existence

In this paper, we propose a modified extragradient method for solving variational inequalities (VI) which has the following nice features: (i) The generated sequence possesses an expansion property with respect to the starting point; (ii) the existence of the solution to a VI problem can be verified through the behavior of the generated sequence from the fact that the iterative sequence diverges to infinity if and only if the solution set is empty. Global convergence of the method is guaranteed under mild conditions. Our preliminary computational experience is also reported.     

Indirect Obstacle Minimax Control for Elliptic Variational Inequalities

A minimax control problem for a coupled system of a semilinear elliptic equation and an obstacle variational inequality is considered. The major novelty of such problem lies in the simultaneous presence of a nonsmooth state equation (variational inequality) and a nonsmooth cost function (sup norm). In this paper, the existence of optimal controls and the optimality conditions are established.     

Extension of the Hybrid Steepest Descent Method to a Class of Variational Inequalities and Fixed Point Problems with Nonself-Mappings

In this paper, we discuss the strong convergence of the hybrid steepest descent method relative to the case when the involved operators belong to a wide class of possibly nonself-mappings. Our convergence results cover previous ones, and the techniques of analysis used are simple and can be adapted to many other fixed point methods.     

四阶半线性椭圆变分不等式正解的存在性

本文通过Leray—Schauder度，给出四阶半线性椭圆变分不等式正解的存在性结果．     

Existence of Value in Stochastic Differential Games of Mixed Type

In this article, we address stochastic differential games of mixed type with both control and stopping times. Under standard assumptions, we show that the value of the game can be characterized as the unique viscosity solution of corresponding Hamilton-Jacobi-Isaacs (HJI) variational inequalities.     

On a variational inequality associated with a stopping game combined with a control

We study a non-linear elliptic variational inequality which corresponds to a zero-sum stopping game (Dynkin game) combined with a control. Our result is a generalization of the existing works by Bensoussan [ Stochastic Control by Functional Analysis Methods (North-Holland, Amsterdam), 1982], Bensoussan and Lions [ Applications des Inéquations Variationnelles en Contrôle Stochastique (Dunod, Paris), 1978] and Friedman [ Stochastic Differential Equations and Applications (Academic Press, New York), 1976] in the sense that a non-linear term appears in the variational inequality, or equivalently, that the underlying process for the corresponding stopping game is subject to a control. By using the dynamic programming principle and the method of penalization, we show the existence and uniqueness of a viscosity solution of the variational inequality and describe it as the value function of the corresponding combined-stochastic game problem.