Existence and approximation of solutions for discontinuous functional differential equations

In this paper existence of solutions of initial value problems for discontinuous functional differential equations is investigated firstly. By applying the method of upper and lower solutions, which may be discontinuous, some existence results of extremal solutions are obtained. Furthermore, we also develop a monotone iterative technique for obtaining extremal solutions which are obtained as limits of monotone sequences.     

不连续泛函微分方程周期边值问题解的单调迭代技巧(英文)

文章通过运用上下解的方法证明了一类带有周期边值条件的不连续泛函微分方程解的存在性.并且采用不连续的上下解显著扩大了上下解的选择范围.进而,通过构造具有一致收敛性的上下解的单调迭代序列,得到了该周期边值问题的极值解,即最大、小解.     

Monotone convergence theorems for Henstock-Kurzweil integrable functions and applications

In this paper we prove monotone convergence theorems for Henstock-Kurzweil integrable functions from a compact real interval to an ordered Banach space. These theorems are then applied to prove existence results for solutions of a discontinuous functional integral equation containing Henstock-Kurzweil integrable functions.     

一类混合单调算子的耦合不动点定理及其应用

讨论了一类混合单调算子的耦合不动点定理,并获得了最大最小耦合不动点.作为应用,讨论了Banach空间中含有不连续项的混合单调Volterra型积分方程耦合拟解的存在性问题.     

MONOTONE ITERATION FOR ELLIPTIC PDEs WITH DISCONTINUOUS NONLINEAR TERMS

In this paper, we use monotone iterative techniques to show the existence of maximal or minimal solutions of some elliptic PDEs with nonlinear discontinuous terms. As the numerical analysis of this PDEs is concerned, we prove the convergence of discrete extremal solutions.     

On solvability of variational inequalities with discontinuous semimonotone operators

By using the method of monotone operators, a theorem on the existence of the solution with a special property is obtained for an elliptic variational inequality with discontinuous semimonotone operator; this theorem is then used to prove the existence of a semicorrect solution of a variational inequality with a differential semilinear high-order operator of elliptic type with a nonsymmetric linear part and discontinuous nonlinearity.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 45, No. 3, pp. 443–447, March, 1993.     

有限域上交错矩阵方程解的计数公式及其q超几何级数表达

设Ｆｑ是ｑ元有限域，这里ｑ是任意一个素数ｐ的方幂。本文利用Ｆｑ上奇异辛几何给出当Ａ，Ｂ分别是阶ｎ秩２ｖ和ｍ秩２ｓ的一般交错矩阵时，Ｆｑ上适合方程ＸＡＸ‘＝Ｂ的秩ｋ的解Ｘ和解Ｘ的个数的明显公式，并用ｑ超几何级数简化表达公式。     

One barrier reflected backward doubly stochastic differential equations with discontinuous monotone coefficients

In this paper, we study one-dimensional reflected backward doubly stochastic differential equations (RBDSDEs) with one continuous barrier and discontinuous (left or right continuous) monotone generator. An existence theorem and a comparison theorem for solutions of the class of RBDSDEs are established. Some known results are extended.     

含间断项的微分方程终值问题的拟上下解方法

在不涉及紧型条件的情形下,利用半序理论和混合单调迭代技术研究了Banach空间中含间断项的一阶微分方程终值问题解的存在唯一性;并给出逼近解迭代序列的误差估计.     

Skorohod problem and multivalued stochastic evolution equations in Banach spaces

By solving a deterministic Skorohod problem in the framework of evolutional triple, we prove the existence and uniqueness of solutions to multivalued stochastic evolution equations involving maximal monotone operators. The existence and uniqueness of invariant measures associated with the solutions as Markov processes are also considered in the present paper. Moreover, we apply the results to stochastic differential equations with normal reflecting boundary conditions and with singular drift terms, as well as a class of multivalued nonlinear stochastic partial differential equations with possibly discontinuous coefficients.     

Multi-valued boundary value problems involving Leray-Lions operators and discontinuous nonlinearities

We prove an existence result for a class of Dirichlet boundary value problems with discontinuous nonlinearity and involving a Leray-Lions operator. The proof combines monotonicity methods for elliptic problems, variational inequality techniques and basic tools related to monotone operators. Our work generalizes a result obtained in Carl [4].     

Asymptotics of the Solution to a Stationary Piecewise-Smooth Reaction-Diffusion-Advection Equation*

A singularly perturbed boundary value problem for a piecewise-smooth nonlinear stationary equation of reaction-diffusion-advection type is studied. A new class of problems in the case when the discontinuous curve which separates the domain is monotone with respect to the time variable is considered. The existence of a smooth solution with an internal layer appearing in the neighborhood of some point on the discontinuous curve is studied. An efficient algorithm for constructing the point itself a...     

具有不连续神经激励的循环神经网络的周期解存在性

本文研究了一类可以描述为右端不连续微分方程的循环神经网络模型.在并不要求激励函数连续、有界及单调非减的情况下,通过利用线性矩阵不等式和微分包含中的Cellina近似选择定理,得到了该神经网络模型存在周期解的充分条件.最后,给出了一个数值例子用以说明本文结果的有效性.     

Stability analysis for periodic solution of neural networks with discontinuous neuron activations

In this paper, we present a general class of neural networks with discontinuous neuron activations and varying coefficients, where the neuron activation function is a discontinuous monotone increasing and bounded function. By using the fixed point theorem in differential inclusion theory and constructing suitable Lyapunov functions, a condition is derived which ensures the existence and global exponential stability of a unique periodic solution for the neural network. Furthermore, under certain conditions global convergence in finite time of the state is investigated. The obtained results show that Forti’s conjecture for neural networks without delays is true. Finally, two numerical examples are given to demonstrate the effectiveness of the results obtained in this paper.     

一阶非连续微分系统解的存在与唯一性

本文讨论了一阶非连续微分系统初值问题和边值问题，在方程右端函数不连续并且不具有任何单调性的情况下，给出了方程的唯一解，并且给出了收敛于方程解的迭代序列。     

Fixed points for mixed monotone multivalued operators in Banach spaces with applications

In this paper, the existence and iterative approximation of fixed points for a class of systems of mixed monotone multivalued operator are discussed. We present some new fixed point theorems of mixed monotone operators and increasing operators which need not be continuous or satisfy a compactness condition. We also give some applications to differential inclusions with discontinuous right hand side in Banach spaces and to Hammerstein integral inclusions on RN.     

Banach空间中含间断项Sturm—Liouville问题的解

利用拟上下解方法和混合单调迭代法,研究了Banach空间中含间断项的非线性Sturm-liouville问题解的存在唯一性,并给出逼近解迭代序列的误差估计．     

Nonlinear elliptic differential equations with multivalued nonlinearities

In this paper we study nonlinear elliptic boundary value problems with monotone and nonmonotone multivalued nonlinearities. First we consider the case of monotone nonlinearities. In the first result we assume that the multivalued nonlinearity is defined on all ℝ. Assuming the existence of an upper and of a lower solution, we prove the existence of a solution between them. Also for a special version of the problem, we prove the existence of extremal solutions in the order interval formed by the upper and lower solutions. Then we drop the requirement that the monotone nonlinearity is defined on all of ℝ. This case is important because it covers variational inequalities. Using the theory of operators of monotone type we show that the problem has a solution. Finally in the last part we consider an eigenvalue problem with a nonmonotone multivalued nonlinearity. Using the critical point theory for nonsmooth locally Lipschitz functionals we prove the existence of at least two nontrivial solutions (multiplicity theorem).     

Existence theorems for monotone operators in reflexive Banach spaces

In this paper, we obtain an existence theorem for single-valued monotone operators in a reflexive Banach space. Using this result, we prove a fixed point theorem for nonexpansive mappings in a Hilbert space and an existence theorem for maximal monotone operators in a Banach space. Received: 3 July 2006 Revised: 15 January 2007     

A Note on Monotone Iteration Method for Traveling Waves of Reaction-Diffusion Systems with Time Delay

For a monotone reaction-diffusion system with or without time delay, a standard approach to show the existence of a mono-stable traveling wave solution is the monotone iteration that requires the construction of a pair of upper and lower solution. In this note we will show that the monotone iteration approach can be improved by just constructing an upper solution. This improvement gives more freedom for the construction of an upper solution.