一类抛物型H-半变分不等式

研究一类拟线性抛物型H-半变分不等式,即研究具有非凸、非光滑泛函的抛物型变分不等式。这类问题的研究来自力学。利用Clarke广义梯度和伪单调算子理论,证明了一类拟线性抛物型H-半变分不等式解的存在性。     

非线性退化抛物变分不等式问题解的存在性和唯一性

本文研究了一类基于非线性抛物算子的变分不等式问题.利用惩罚方法获得了一些关于该变分不等式解的存在性和唯一性方面的结论.该结论是对变分不等式理论的推广.     

具有双障碍的退缩抛物变分不等式解的存在性和唯一性

本文研究具有双障碍的退缩抛物变分不等式，我们利用罚技巧，有限逼近和先验估计方法，得到一类退缩抛物变分不等式弱解的存在性，并在一定条件下，建立了弱解的唯一性。本文结论对广泛的一类抛物物型变分不等式成立。     

广义集值强非线性混合似变分不等式解的迭代逼近

延拓辅助原理的技巧研究一类取非紧值的集值映象的广义强非线性混合似变分不等式．证明了这类广义强非线性混合似变分不等式的辅助问题解的存在性．利用该存在性结果,给出了解这类广义强非线性混合似变分不等式的迭代算法,最终证明了这类广义强非线性混合似变分不等式解的存在性及由算法生成的迭代序列的收敛性．     

一类非线性拋物变分不等式解的存在性

本文研究了一类基于非线性抛物算子的变分不等式问题.首先,通过拓展偏微分方程的弱解理论定义了变分不等式的弱解.其次,利用惩罚函数并结合连续方法,证明了变分不等式存在弱解.     

星形集约束微分变分不等式解的存在性北大核心CSCD

由微分方程和变分不等式构成的微分变分不等式是非线性分析及其应用领域中的一类非常重要的问题,吸引了不少学者的极大关注和探索.本文研究一类具有非凸约束的微分变分不等式新问题的解的存在性.该类问题中的变分不等式的约束集是关于某一球的星形集,使得可以利用距离函数的广义Clarke次微分的不连续性质.我们通过多值伪单调算子的满射定理,H-半变分不等式逼近和参数不需要趋于零的罚方法证明解的存在性,并举例说明主要结果在具有非凸约束的抛物型初值问题中的应用.     

广义集值强非线性混合似变分不等式解的迭代逼近

辅助原理的技巧被延拓来研究一类取非紧值的集值映象的广义强非线性混合似变分不等式.首先,证明了这类广义强非线性混合似变分不等式的辅助问题解的存在性.其次,利用该存在性结果,给出了解这类广义强非线性混合似变分不等式的迭代算法.最后,不仅证明了这类广义强非线性混合似变分不等式解的存在性,而且证明了由算法生成的迭代序列的收敛性.     

带梯度障碍的抛物型变分不等式解的存在性唯一性和正则性

本文讨论带梯度障碍的抛物型变分不等式解的存在性、唯一性和正则性问题．通过证明一类带梯度障碍的问题的求解等价于解某个双边障碍的问题，并利用双边障碍问题解的存在性、唯一性和正则性，得到了带梯度障碍的问题的相应结果．这一方法将有助于对具有梯度约束的非线性以及完全非线性抛物型方程解的正则性的研究．     

具有双障碍的退缩抛物变分不等式解的存在性和唯一性(英)

本文研究具有双障碍的退缩抛物变分不等式．我们利用罚技巧，有限逼近和先验估计方法，得到一类退缩抛物变分不等式弱解的存在性，并在一定条件之下，建立了弱解的唯一性．本文结论对广泛的一类抛物型变分不等式成立．     

抛物型H-半变分不等式的收敛性

本文讨论的对象是非线性抛物型H-半变分不等式，使用文献[4]中抛物型G收敛的定义来研究抛物型H-半变分不等式解的收敛性行为。     

Existence results for quasilinear parabolic hemivariational inequalities

This paper is devoted to the periodic problem for quasilinear parabolic hemivariational inequalities at resonance as well as at nonresonance. By use of the theory of multi-valued pseudomonotone operators, the notion of generalized gradient of Clarke and the property of the first eigenfunction, we build a Landesman-Lazer theory in the nonsmooth framework of quasilinear parabolic hemivariational inequalities.     

Durchmesserabschätzungen für die einheitskugel des sobolev-raumes

Theory of parabolic differential inequalities, flow-invariance of solutions and comparison theorems are discussed relative to a cone.

In this paper we investigate the theory of parabolic differential inequalities in arbitrary cones. After discussing the fundamental results concerning parabolic inequalities in cones, we prove a result on flow-invariance which is then used to obtain a comparison theorem. This comparison result is useful in deriving upper and lower bounds on solutions of parabolic differential equations in terms of the solutions of ordinary differential equations. We treat the Dirichlet problem in this paper since its theory follows the general pattern of ordinary differential equations and requires less restrictive assumptions. The treatment of Neumann problem, on the other hand, demands stronger smoothness assumptions and depends heavily on strong maximum principle. The study of the corresponding results relative to Neumann problem is discussed elsewhere.     

Dynamic thermoviscoelastic problem with friction and damage

In this paper we present a model of dynamic frictional contact between a thermoviscoelastic body and a foundation. The thermoviscoelastic constitutive law includes a temperature effect described by the parabolic equation with the subdifferential boundary condition and a damage effect described by the parabolic inclusion with the homogeneous Neumann boundary condition. Contact is modeled with bilateral condition and is associated to a subdifferential frictional law. The variational formulation of the problem leads to a system of hyperbolic hemivariational inequality for the displacement, parabolic hemivariational inequality for the temperature and parabolic variational inequality for the damage. The existence of a unique weak solution is proved by using recent results from the theory of hemivariational inequalities, variational inequalities, and a fixed point argument.     

A theory of discretization for nonlinear evolution inequalities applied to parabolic Signorini problems

We present a discretization theory for a class of nonlinear evolution inequalities that encompasses time dependent monotone operator equations and parabolic variational inequalities. This discretization theory combines a backward Euler scheme for time discretization and the Galerkin method for space discretization. We include set convergence of convex subsets in the sense of Glowinski-Mosco-Stummel to allow a nonconforming approximation of unilateral constraints. As an application we treat parabolic Signorini problems involving the p-Laplacian, where we use standard piecewise polynomial finite elements for space discretization. Without imposing any regularity assumption for the solution we establish various norm convergence results for piecewise linear as well piecewise quadratic trial functions, which in the latter case leads to a nonconforming approximation scheme. Entrata in Redazione il 16 marzo 1998, in versione riveduta il 15 febbraio 1999.     

Reverse Hölder inequalities for singular parabolic equations near the boundary

We show that weak solutions to a singular parabolic partial differential equation globally belong to a higher Sobolev space than assumed a priori. To this end, we prove that the gradients satisfy a reverse Hölder inequality near the boundary. The results extend to singular parabolic systems as well. Motivation for studying reverse Hölder inequalities comes partly from applications to regularity theory.     

二阶椭圆和抛物型偏微分方程的非线性非局部边值问题与温控系统稳定性

本文讨论了由温度控制中提出的二阶椭圆和抛物型偏微分方程的非线性非局部边值问题.通过把问题化为变分不等方程,利用单调算子理论、凸分析和非线性发展方程理论,研究了其弱解的适定性和增长估计.证明了当反馈因(辶回)路的总增益适当小的时候,系统是全局渐近稳定的.     

Generalized evolution variational inequalities and their applications to partial differential equations

We study the existence of solutions to generalized evolution vari ational inequalities by pseudomonotone mapping theory. We obtain results which generalize and extend previously known theorems. We then apply our results to parabolic partial differential equations with discontinuous nonlinearities.     

A comparison principle for weak solutions of the Cauchy problem for quasilinear parabolic inequalities

We obtain a new comparison principle for weak solutions of the Cauchy problem for a wide class of quasilinear parabolic inequalities. This is a nonlinear result with no analogue in linear theory. Received: 13 January 2005