共查询到20条相似文献,搜索用时 109 毫秒
1.
张海娥 《数学的实践与认识》2012,42(23)
运用Guo-Krasnoselskii不动点定理研究了带积分边界条件的奇异三阶非局部边值问题,在非线性项满足适当的条件下建立了关于参数的区间,得到了边值问题至少存在一个或两个单调正解的若干存在性结果. 相似文献
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研究分数阶微分方程组边值问题在一类新型的边界条件——分数阶分离边界条件下解的存在性.通过将微分方程组边值问题转化为与之等价的积分方程组,利用Banach不动点定理和Leray-Schauder非线性更替得到边值问题解存在的充分条件,并给出两个例子说明了主要结论. 相似文献
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研究了一类广义抛物型方程奇摄动问题.首先在一定的条件下, 提出了一类具有两参数的非线性非局部广义抛物型方程初始 边值问题.其次证明了相应问题解的存在性.然后, 通过Fredholm积分方程得到了初始 边值问题的外部解.再利用泛函分析理论和伸长变量及多重尺度法, 分别构造了初始 边值问题广义解的边界层、初始层项,从而得到了问题的形式渐近展开式.最后利用不动点理论证明了对应的非线性非局部广义抛物型方程的奇异摄动初始 边值问题的广义解的渐近展开式的一致有效性. 相似文献
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在准静态弹性力学中常遇到求解带有非局部边界条件的抛物方程初边值问题.本文构造了一个数值求解带有非局部边界条件的非线性抛物方程的隐式差分格式,利用离散泛函分析的知识和不动点定理证明了差分解是存在的,且在离散最大模意义下关于时间步长一阶收敛,关于空间步长二阶收敛,并给出了数值算例. 相似文献
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近来非局部问题的研究日见增多,但涉及带非线性边界条件的初值问题文献 较少.本文目的在于证明一个半线性方程的齐次边值问题和一个非线性边界条件问题 解的存在性.主要使用半群,分数次幂函数空间,广义Poincare算子等工具. 相似文献
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本文讨论基于不光滑边界的变系数抛物型方程求解的高精度紧格式.首先构造一般变系数抛物型方程的高精度紧格式,并在理论上证明格式具有空间方向四阶精度.然后针对非光滑边界条件,引入局部网格加密技巧在奇异点附近进行不均匀的网格加密.数值实验以期权定价中Black-Scholes偏微分方程的求解为例,验证高精度紧格式用于光滑边界条件的微分方程离散可以达到四阶精度.对于处理非光滑边界条件,网格局部加密技巧能有效的提高数值解精度,使得高精度紧格式用于定价欧式期权可以接近四阶精度. 相似文献
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一类具有非局部边界条件的反应扩散方程奇摄动问题 总被引:8,自引:0,他引:8
该文研究了一类具有非局部边界条件的奇摄动反应扩散初始边值问题。在适当的条件下,利用比较定理讨论了问题解的渐近性态。 相似文献
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本文研究了一类具有非局部边界条件的奇摄动半线性椭圆型方程边值问题。在适当的条件下,利用比较定理讨论了问题解的渐近性态。 相似文献
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É. A. Gasymov 《Differential Equations》2011,47(3):319-332
We consider a mixed problem with integro-differential boundary conditions for a nonclassical equation. Under certain conditions,
we apply a finite integral transform to this problem and obtain a parametric problem. We introduce the notion of proper boundary
conditions of the parametric problem, which is wider than the notion of regularity. By applying the inverse integral transform
to the solution of the parametric problem, we obtain an analytic representation of the solution of the original mixed problem. 相似文献
12.
D. Medková 《Acta Appl Math》2011,116(3):281-304
A weak solution of the Neumann problem for the Stokes system in Sobolev space is studied in a bounded Lipschitz domain with
connected boundary. A solution is looked for in the form of a hydrodynamical single layer potential. It leads to an integral
equation on the boundary of the domain. Necessary and sufficient conditions for the solvability of the problem are given.
Moreover, it is shown that we can obtain a solution of this integral equation using the successive approximation method. Then
the consequences for the direct boundary integral equation method are treated. A solution of the Neumann problem for the Stokes
system is the sum of the hydrodynamical single layer potential corresponding to the boundary condition and the hydrodynamical
double layer potential corresponding to the trace of the velocity part of the solution. Using boundary behavior of potentials
we get an integral equation on the boundary of the domain where the trace of the velocity part of the solution is unknown.
It is shown that we can obtain a solution of this integral equation using the successive approximation method. 相似文献
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P.A. Krutitskii 《Advances in Mathematics》2003,177(2):208-226
Method of boundary integral equations is applied to the initial-boundary value problem for an equation of fourth order and composite type in 3-D multiply connected domain with Dirichlet boundary condition. The problem controls nonsteady internal gravity waves in a stratified fluid. The problem is reduced to the time-dependent integral equation. It is shown that the integral equation is solvable. The solution of the problem is obtained in the form of dynamic potentials. The density in potentials obeys this integral equation. Therefore, the existence theorem is proved. Besides, the uniqueness of the solution is studied. All results hold for both interior and exterior domains with appropriate conditions at infinity. 相似文献
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On an integral representation of the solution of the Laplace equation with mixed boundary conditions
T. E. Moiseev 《Differential Equations》2011,47(10):1461-1467
We obtain an integral representation of the solution of the Laplace equation with three distinct boundary conditions. Depending
on the statement of the problem, the homogeneous boundary value problem may have nontrivial solutions; in other cases, the
solution of the homogeneous problem is zero. Note that the inhomogeneous problem is always solvable. 相似文献
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We consider a nonlinear spectral problem for a self-adjoint Hamiltonian system of differential equations. The boundary conditions correspond to a self-adjoint problem. It is assumed that the input data (the matrix of the system and the matrices of the boundary conditions) satisfy certain conditions of monotonicity with respect to the spectral parameter. In addition to the main boundary conditions, a redundant nonlocal condition given by a Stieltjes integral is imposed on the solution. For the nontrivial solvability of the over-determined problem thus obtained, the original problem is replaced by an auxiliary problem that is consistent with the entire set of conditions. This auxiliary problem is obtained from the original one by allowing a discrepancy of a specific form. We study the resulting problem and give a numerical method for its solution. 相似文献
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The paper contains an elementary investigation of the questionof uniqueness of a pair of integral equations connected withthe plane biharmonic problem. It is shown that for two particularexceptional geometries of the boundary curve the pair of integralequations does not have a unique solution. This defect can beremoved by adding two supplementary integral conditions whichthe solution of the integral equations must satisfy. As an illustrationthe integral equations are solved numerically with and withoutthese extra conditions. 相似文献
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In this paper an inverse method for solving elastostatic problems with incomplete boundary conditions is presented. In general, inverse problems are ill-posed boundary value problems whose stability and uniqueness of solution and sensitivity-based formulations require additional constraints. In the development we use the Betti-reciprocal theorem to represent the boundary traction field in terms of the boundary and field displacements in an integral form. Initially, we assume the unknown boundary conditions and deformations required to solve the problem. In this way we equate the work done by the exact solution (unknown) to the work done by an assumed solution. Discretizing the resulting equations and using an iterative procedure each step in the solution process becomes the solution to a well-posed problem. Thus, with sufficient perturbations the correct boundary conditions are reconstructed. 相似文献