巴拿赫空间中半群指数吸引子的存在性

We construct an exponential attractor for semigroup in Banach space by using ω-limit compactness method and provide a new method to prove the existence of an exponential attractor in uniformly convex Banach space. As a simple application, we prove the existence of an exponential attractor for reaction diffusion equations.     

The Bonnesen isoperimetric inequality in a surface of constant curvature

We first estimate the containment measure of a convex domain to contain in another in a surface X of constant curvature.Then we obtain the analogue of the known Bonnesen isoperimetric inequality for convex domain in X.Finally we strengthen the known Bonnesen isoperimetric inequality.     

Global regularity for a class of Monge-Ampère type equations

In this paper we are concerned with the global regularity of solutions to the Dirichlet problem for a class of Monge-Ampère type equations.By employing the concept of(a,η) type domain,we emphasize that the boundary regularity depends on the convexity of the domain in nature.The key idea of our proof is to provide more effective global H?lder estimates of convex solutions to the problem based on carefully choosing auxiliary functions and constructing sub-solutions.     

MULTIGRID METHODS FOR THE GENERALIZED STOKES EQUATIONS BASED ON MIXED FINITE ELEMENT METHODS

1. IntroductionIn this paper, we consider the fOllowing generalized stationary Stokes equations:where fl is a bounded convex domain in R', u represents the velocity of fluid, p its pressure; Fand G are external fOrce and source terms. Note that the source…     

(mM)∞算子及Hamilton-Jacobi方程粘性解

Hamilton-Jacobi equations are frequently encountered in applications, e.g. , in control theory, differential games, and theory of economics, construct viscosity solutions of Hamilton-Jacobi equations having a nonconvex flux and a nonconvex initial value. The main idea is. decomposit flux into convex flux plus concave flux, with the help of a newly designed operator (mM)^∞ and Legendre transform, the viscosity solutions of Hamilton-Jacobi equations can be exactly ex-pressed. The (mM)^∞ type Solutions is proved to be the viscosity solutions ofHamilton-Jacobi equations. In fact our ( (mM)^∞ ) formula is a nonconvex generalization of the convex Lax-Oleinik-Hopf’s formula.     

THE LERAY-SCHAUDER CONDITION FOR 1-SET WEAKLY-CONTRACTIVE AND （ws）-COMPACT OPERATORS

Abstract The main purpose of this article is to prove a collection of new nxea point theorems for （ws）-compact and so-called 1-set weakly contractive operators under Leray- Schauder boundary condition. We also introduce the concept of semi-closed operator at the origin and obtain a series of new fixed point theorems for such class of operators. As consequences, we get new fixed point existence for （ws）-compact （in particular nonexpansive） self mappings unbounded closed convex subset of Banach spaces. The main condition in our results is formulated in terms of axiomatic measures of weak noncompactness. Later on, we give an application to generalized Hammerstein type integral equations.     

THE GENERALIZED SINE-GORDEN EQUATIONS AND THEIR GEOMETRIC ASPECTS

§1 INTRODUCTION The work on"Lie group and KDV equations" has been done in[1]. From the structure equations of certain Lie Group, a class of evolution equations of Sine-Gorden type may be achieved. In this paper from a new viewpoint introduced in [2], we will derive a class of evolution equations of Sine-Gorden type. Furthermore we have given geometric interoretations for our evolution equations of Sine-Gorden type. The evolution equations of Sine-Gorden type which have been got in [3] are a special class of our paper.     

The Stable Farkas Lemma for composite convex functions in infinite dimensional spaces

In this paper, we consider a general composite convex optimization problem with a cone-convex system in locally convex Hausdorff topological vector spaces. Some Fenchel conjugate transforms for the composite convex functions are derived to obtain the equivalent condition of the Stable Farkas Lemma, which is formulated by using the epigraph of the conjugates for the convex functions involved and turns out to be weaker than the classic Slater condition. Moreover, we get some necessary and sufficient conditions for stable duality results of the composite convex functions and present an example to illustrate that the monotonic increasing property of the outer convex function in the objective function is essential. Our main results in this paper develop some recently results.     

Fixed Points of Cone Maps in Locally Convex Spaces

Guo [1] gives some fixed point theorems of cone maps in Banacb space. Here we generalize the main resnlts of [1] to a locally convex space. We remark that the approach in [1] is not applicable in our paper. Throughout this paper. X is a Hausdorff locally convex topological vector space over the field of real numbers, K is a closed convex subset     

Continuity of Some Classes of Functions Related to Degenerate Parabolic Equations and Its Applications

We study some classes of functions satisfying the assumptions similar to but weaker than those for the classical B2 function classes used in the research of quasi-linear parabolic equations as well as the ones used in the research of degenerate parabolic equations including porous medium equations. Consequently, we prove that a function in such a class is continuous. As an application, we obtain the estimate for the continuous modulus of the solutions of a few degenerate parabolic equations in divergence form, including the anisotropic porous equations.     

Second Order Derivative Estimates of the Solutions of a Class of Monge-Ampère Equations

In this paper, we consider a class of Monge-Amp`ere equations in relative differential geometry. Given these equations with zero boundary values in a smooth strictly convex bounded domain, we obtain second order derivative estimates of the convex solutions.     

Radially symmetric convex solutions for Dirichlet problems of Monge‐Ampère equations

In this paper, we study the existence of radially symmetric convex solutions for Dirichlet problems of Monge‐Ampère equations. By applying a well‐known fixed point theorem in cones, we shall establish several new criteria for the existence of nontrivial radially symmetric convex solutions for the systems of Monge‐Ampère equations with or without an eigenvalue parameter. Copyright © 2015 John Wiley & Sons, Ltd.     

Quelques rémarques sur le feedback stationnaire et la stabilté asymptotique

Summary We consider dynamical systems described by asymptotically stable equations of evolution and we apply to them feedback laws, optimal in stationary conditions with respect to a usual quadratic functional. Then we study the asymptotic stability of the modified equations of evolution and the convergence of the state variables to the optimal stationary states. We get positive results in the following cases: abstract parabolic equations, heat equation with boundary control and observation, convex constraints on the control variable, non linear equations involving gradients of some convex functions.

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Entrata in Redazione il 22 luglio 1974.     

A microscopic convexity principle for spacetime convex solutions of fully nonlinear parabolic equations

We study microscopic spacetime convexity properties of fully nonlinear parabolic partial differential equations. Under certain general structure condition, we establish a constant rank theorem for the spacetime convex solutions of fully nonlinear parabolic equations. At last, we consider the parabolic convexity of solutions to parabolic equations and the convexity of the spacetime second fundamental form of geometric flows.     

Abstract Volterra Integro-Differential Equations: Approximation and Convergence of Resolvent Operator Families

In this article, we analyze approximation and convergence of resolvent operator families associated with various types of abstract Volterra equations and abstract multi-term fractional differential equations in locally convex spaces.     

解有界变量凸规划问题的ODE方法

用微分方程的解曲线确定约束优化问题的解即ODE方法已受到人们广泛重视和研究.潘平奇对无约束和带等式约束优化问题提出了很好的ODE方法.该方法的主要优点之一是没有扩大问题的规模.关于带不等式约束的优化问题的ODE方法,尚待研究.另外,虽然问题(1)可以通过标准化处理变成等式约束情形,再用[3]中的ODE方法求解,但这样做会扩大问题规模,因此,本文将在不扩大问题规模的基础上     

Nonlocal Geometric Expansion of Convex Planar Curves

We consider a class of nonlocal geometric equations for expanding curves in the plane, arising in the study of evolutions governed by Monge-Kantorovich mass transfer. We construct convex solutions, given convex initial data. In order to obtain such solutions, we develop a new version of Perron's method. We give applications to the problem of characterizing fast/slow diffusion limits.     

Centered solutions for uncertain linear equations

Our contribution is twofold. Firstly, for a system of uncertain linear equations where the uncertainties are column-wise and reside in general convex sets, we derive convex representations for united and tolerable solution sets. Secondly, to obtain centered solutions for uncertain linear equations, we develop a new method based on adjustable robust optimization (ARO) techniques to compute the maximum size inscribed convex body (MCB) of the set of the solutions. In general, the obtained MCB is an inner approximation of the solution set, and its center is a potential solution to the system. We use recent results from ARO to characterize for which convex bodies the obtained MCB is optimal. We compare our method both theoretically and numerically with an existing method that minimizes the worst-case violation. Applications to the input–output model, Colley’s Matrix Rankings and Article Influence Scores demonstrate the advantages of the new method.     

Optimality conditions for stochastic boundary control problems governed by semilinear parabolic equations

We study the boundary control problems for stochastic parabolic equations with Neumann boundary conditions. Imposing super-parabolic conditions, we establish the existence and uniqueness of the solution of state and adjoint equations with non-homogeneous boundary conditions by the Galerkin approximations method. We also find that, in this case, the adjoint equation (BSPDE) has two boundary conditions (one is non-homogeneous, the other is homogeneous). By these results we derive necessary optimality conditions for the control systems under convex state constraints by the convex perturbation method.     

局部凸空间中一类非线性Volterra型积分方程解的存在性

首先利用局部凸空间非紧性测度得到一个新的不动点定理;并运用此定理研究了局部凸空间非线性V o lterra型积分方程解的存在性,然后应用到弱拓扑结构下对非线性V o lterra型积分方程解的存在性的讨论.推广了原有文献的结果.