利用边界元法求解一类重调和方程

边界元法(BEM)和多重互易法(MRM)相结合求解一类重调和方程.通过重调和基本解序列给出的MRM-方法和BEM, 推导出该类问题的MRM-边界变分方程, 用边界元法求解该变分方程, 从而得到重调和方程的近似解, 并给出了解的存在唯一性证明.通过数值算例说明了MRM-方法具有收敛速度快、计算精度高, 易编程等优点, 为使用边界元法数值求解重调和方程提供了方法和理论依据.适合于工程中的实际运算.     

广义集值强非线性混合似变分不等式的辅助原理和三步迭代算法

使用辅助原理技巧研究了一类广义集值强非线性混合变分不等式．证明了此类集值强非线性混合变分不等式辅助问题解的存在性和唯一性;构建了一个新的三步迭代算法,通过辅助原理技巧,构建并计算此类非线性混合变分不等式的近似解,进一步证明非线性混合变分不等式解的存在性以及由算法产生的三个序列的收敛性．所得结论推广了近年来许多混合变分不等式和准变分不等式以及他们的有关结果．     

关于文章“Hilbert空间中变分不等式问题的次外梯度方法的强收敛”的一个注（英文）

本文修正了Censor等人(2011)发表文章里定理6.1的证明方法.利用序列的强收敛将单调变分不等式推广为伪单调变分不等式.因而,推广了Censor等人的结果.     

参数变分不等式的灵敏性分析

本文在所给函数和映射均不可微的前提下，通过建立参数变分不等式和参数Wiener-Hopf方程的等价性，分析了Hilbert空间中参数变分不等式的局部唯一解的灵敏性。文中所用方法是N.D.Yen之方法的改进，使用这一方法可大大简化N.D.Yen一文中主要结果（引理2.1)的证明。     

求解HJB方程的拟变分不等式组的迭代法

本文对HJB方程的拟变分不等式组提出一种迭代算法,并给出此算法在一定的条件下的单调性定理和证明,数值试验表明此法有效的.     

Banach空间中强伪单调变分不等式解的唯一性和稳定性

在自反Banach空间中证明强伪单调变分不等式解的存在唯一性定理.在此基础上研究扰动变分不等式解的稳定性.此外,也在有限维空间中得到了强拟单调变分不等式解的存在性定理.     

Banach空间中微分变分不等式系统的Bang-Bang准则

该文将讨论一类由半线性发展方程和广义变分不等式所组成的微分变分不等式系统.首先,考虑广义变分不等式解集的性质.其次,通过利用不动点定理和半群理论证明了微分变分不等式系统解的存在性.另外,通过运用稠定性结果证明了微分变分不等式系统的Bang-Bang准则.同时,运用一个障碍型抛物-椭圆系统来检验该文的主要结果.     

A-调和方程弱解的新的加权积分不等式

研究形如div A(x,u(x))=0的A-调和方程,证明其弱解满足局部Arλ3(λ1,λ2,Ω)-权Caccioppoli型不等式,这可看作A-调和方程相应结果的推广.最后给出上述结果在拟正则映射中的应用.     

H-空间中的变分不等式

本文利用W—对应，推广了Kok Keong Tan等人证明的变分不等式，并在H空间中，利用新的连续选择定理建立了一个广义变分不等式。     

关于混合拟似变分包含问题的解的迭代算法

本文对混合拟似变分包含问题提出新的辅助变分不等式,首先证明辅助变分不等式存在唯一解.然后,通过这一辅助形式建立混和拟似变分包含问题解的迭代算法.最后讨论在新的算法下迭代解的收敛性.     

On a contact problem for a viscoelastic von Karman plate and its semidiscretization

We deal with the system describing moderately large deflections of thin viscoelastic plates with an inner obstacle. In the case of a long memory the system consists of an integro-differential 4th order variational inequality for the deflection and an equation with a biharmonic left-hand side and an integro-differential right-hand side for the Airy stress function. The existence of a solution in a special case of the Dirichlet-Prony series is verified by transforming the problem into a sequence of stationary variational inequalities of von Karman type. We derive conditions for applying the Banach fixed point theorem enabling us to solve the biharmonic variational inequalities for each time step.     

Plate Contact问题的混合有限元逼近

论文考虑了Plate Contact问题的混合有限元逼近,其变分问题为第二类四阶椭圆变分不等问题.首先,根据正则化方法,得到原问题的正则化问题.再根据网格依赖范数技巧,考虑了正则化问题的Ciarlet-Raviart混合有限元逼近,并证明了真解与逼近解之间的误差估计.最后通过数值算例验证了理论分析的结果.     

An FEM approximation for a fourth-order variational inequality of second kind

A fourth-order variational inequality of the second kind arising in a plate frictional bending problem is considered. By using regularization method, the original problem can be formulated as a differentiable variational equation, and the corresponding discrete FEM variational equation is presented afterwards. Abstract error estimates and error estimates of the approximation are derived in terms of energy norm and L^2-norm.     

盒子型区域上变分不等式的一个光滑牛顿法(英文)

The box constrained variational inequality problem can be reformulated as a nonsmooth equation by using median operator.In this paper,we present a smoothing Newton method for solving the box constrained variational inequality problem based on a new smoothing approximation function.The proposed algorithm is proved to be well defined and convergent globally under weaker conditions.     

On the regularity of the solution of the biharmonic variational inequality

It is shown that the solution of the biharmonic variational inequality has bounded second derivatives provided that the obstacle and the data are smooth.During the preparation of a portion of the paper, the author was a guest of the Scuola Normale Superiore in Pisa, supported by the German Research Association (DFG).     

Differential variational inequalities in infinite banach spaces

In this paper, we consider a new differential variational inequality (DVI, for short) which is composed of an evolution equation and a variational inequality in infinite Banach spaces. This kind of problems may be regarded as a special feedback control problem. Based on the Browder's theorem and the optimal control theory, we show the existence of solutions to the mentioned problem.     

A preconditioner for a kind of coupled FEM-BEM variational inequality

In this paper we are concerned with a kind of nonlinear transmission problem with Signorini contact conditions. This problem can be described by a coupled FEM-BEM variational inequality. We first develop a preconditioning gradient projection method for solving the variational inequality. Then we construct an effective domain decomposition preconditioner for the discrete system. The preconditioner makes the coupled inequality problem be decomposed into an equation problem and a “small” inequality problem, which can be solved in parallel. We give a complete analysis to the convergence speed of this iterative method.     

Boundedness of the Hessian of a Biharmonic Function in a Convex Domain

We consider the Dirichlet problem for the biharmonic equation on an arbitrary convex domain and prove that the second derivatives of the variational solution are bounded in all dimensions.     

Existence of positive solutions to quasi-linear elliptic equations with exponential growth in the whole Euclidean space

In this paper a quasi-linear elliptic equation in the whole Euclidean space is considered. The nonlinearity of the equation is assumed to have exponential growth or have critical growth in view of Trudinger–Moser type inequality. Under some assumptions on the potential and the nonlinearity, it is proved that there is a nontrivial positive weak solution to this equation. Also it is shown that there are two distinct positive weak solutions to a perturbation of the equation. The method of proving these results is combining Trudinger–Moser type inequality, Mountain-pass theorem and Ekeland?s variational principle.