共查询到20条相似文献,搜索用时 140 毫秒
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本文得到了具转向点的二阶常微分方程混合边值问题解的导数估计,提出了Il′in型差分格式,证明了此差分格式按L~1模关于小参数ε的一阶一致收敛性。最后,给出了一个数值例子,计算结果与理论分析一致。 相似文献
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各向异性网格下抛物方程一个新的非协调混合元收敛性分析 总被引:1,自引:0,他引:1
本文将 Crouzeix-Raviart 型非协调线性三角形元应用到抛物方程,建立了一个新的混合元格式.在抛弃传统有限元分析的必要工具 Ritz 投影算子的前提下,直接利用单元的插值性质和导数转移技巧, 分别得到了各向异性剖分下关于原始变量u 的H-1-模和积分意义下L2-模以及通量p=-▽u 在L2-模下的最优阶误差估计.数值结果与我们的理论分析是相吻合的. 相似文献
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文章采用Legendre—tau方法对一阶双曲方程进行数值求解,此方法可以被有效实施,且可以得到L^2模意义下的最优误差估计,将以往对此类问题的收敛阶估计由O(N^1-τ)提高到O(N^-τ),改进了原有的理论分析结果,数值算例证实了此方法的有效性. 相似文献
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《数学物理学报(A辑)》2017,(5)
该文主要研究一维非线性抛物问题两层网格有限体积元逼近.对一维非线性抛物问题有限体积元解的存在性进行了讨论,给出了最优阶L~2-模和H~1-模误差估计结果,并研究了其两层网格算法.证明了当粗细网格步长满足h=O(H~2)时两层网格算法具有最优阶H~1-模误差估计.数值算例验证了理论结果. 相似文献
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讨论具有非线性耗散项双曲系统的初值问题,对初值的模不加小性假设,而要求其一阶导数适当小情形下,证明其光滑解的整体存在性,并用经典解的特征线法获得解的模估计,同时应用极值原理得到解的偏导数的一致估计. 相似文献
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Cahn-Hilliard方程的有限元分析 总被引:2,自引:1,他引:1
建立了求解非线性发展型Cahn-Hilliard方程的有限元方法,借助于一个双调和问题的有限元投影逼近,给出了最优阶L_2模误差估计。特别对于3次Hermite型有限元,导出了L_∞模和W_∞~1模的最优阶误差估计和导数逼近的超收敛结果。 相似文献
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《Applied mathematics and computation》2007,189(2):1304-1319
A kind of second-order quasi-linear hyperbolic equation is firstly transformed into a first-order system of equations, then the Galerkin alternating-direction procedure for the system is derived. The optimal order estimates in H1 norm and L2 norm of the procedure are obtained respectively by using the theory and techniques of priori estimate of differential equations. The numerical experiment is also given to support the theoretical analysis. Comparing the results of numerical example with the theoretical analysis, they are uniform. 相似文献
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A new first‐order formulation for the two‐dimensional elasticity equations is proposed by introducing additional variables which, called stresses here, are the derivatives of displacements. The resulted stress–displacement system can be further decomposed into two dependent subsystems, the stress system and the displacement system recovered from the stresses. For constructing finite element approximations to these subsystems with appropriate boundary conditions, a two‐stage least‐squares procedure is introduced. The analysis shows that, under suitable regularity assumptions, the rates of convergence of the least‐squares approximations for all the unknowns are optimal both in the H1‐norm and in L2‐norm. Also, numerical experiments with various Poisson's ratios are examined to demonstrate the theoretical estimates. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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Hui Guo 《Journal of Applied Mathematics and Computing》2012,39(1-2):271-301
In this article, we establish a new mixed finite element procedure to solve the second-order hyperbolic and pseudo-hyperbolic integro-differential equations, in which the mixed element system is symmetric positive definite without requiring the LBB consistency condition. Convergence analysis shows that the method yields the approximate solutions with optimal accuracy in L 2(??) norm for u and in H(?div;??) norm for the flux???. Numerical experiments are given to verify the theoretical results. 相似文献
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Zhenzhen Li Dongyang Shi Minghao Li 《Mathematical Methods in the Applied Sciences》2019,42(2):605-619
In this paper, the stabilized mixed finite element methods are presented for the Navier‐Stokes equations with damping. The existence and uniqueness of the weak solutions are proven by use of the Brouwer fixed‐point theorem. Then, optimal error estimates for the H1‐norm and L2‐norm of the velocity and the L2‐norm of the pressure are derived. Moreover, on the basis of the optimal L2‐norm error estimate of the velocity, a stabilized two‐step method is proposed, which is more efficient than the usual stabilized methods. Finally, two numerical examples are implemented to confirm the theoretical analysis. 相似文献
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Dongyang Shi Huaijun Yang 《Numerical Methods for Partial Differential Equations》2019,35(3):1206-1223
This article concerns with the superconvergence analysis of bilinear finite element method (FEM) for nonlinear Poisson–Nernst–Planck (PNP) equations. By employing high accuracy integral identities together with mean value technique, the superclose estimates in H1‐norm are derived for the semi‐discrete and the backward Euler fully‐discrete schemes, which improve the suboptimal error estimate in L2‐norm in the previous literature. Furthermore, the global superconvergence results in H1‐norm are obtained through interpolation postprocessing approach. Finally, a numerical example is provided to confirm the theoretical analysis. 相似文献
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We propose and analyze a spectral Jacobi-collocation approximation for fractional order integro-differential equations of Volterra type. The fractional derivative is described in the Caputo sense. We provide a rigorous error analysis for the collection method, which shows that the errors of the approximate solution decay exponentially in L∞ norm and weighted L2-norm. The numerical examples are given to illustrate the theoretical results. 相似文献
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In this article, a compact finite difference scheme for the coupled nonlinear Schrödinger equations is studied. The scheme is proved to conserve the original conservative properties. Unconditional stability and convergence in maximum norm with order O(τ2 + h4) are also proved by the discrete energy method. Finally, numerical results are provided to verify the theoretical analysis. 相似文献
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Yoshiki Sugitani 《Applications of Mathematics》2017,62(5):459-476
Numerical analysis of a model Stokes interface problem with the homogeneous Dirichlet boundary condition is considered. The interface condition is interpreted as an additional singular force field to the Stokes equations using the characteristic function. The finite element method is applied after introducing a regularization of the singular source term. Consequently, the error is divided into the regularization and discretization parts which are studied separately. As a result, error estimates of order h1/2 in H1 × L2 norm for the velocity and pressure, and of order h in L2 norm for the velocity are derived. Those theoretical results are also verified by numerical examples. 相似文献
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《Numerical Methods for Partial Differential Equations》2018,34(1):336-356
In this article, we study the superconvergence analysis of conforming bilinear finite element method (FEM) for nonlinear Joule heating equations. Based on the rigorous estimates together with high accuracy analysis of this element, mean value technique and interpolation postprocessing approach, the superclose and superconvergent estimates about the related variables in H1‐norm are derived for semidiscrete and a linearized backward Euler fully discrete schemes, which extends the results of optimal estimates obtained for conforming FEMs in the previous literature. At last, a numerical experiment is performed to verify the theoretical analysis. 相似文献
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This paper deals with the numerical solution of optimal control problems, where the state equations are given by the fourth order elliptic partial differential equations. An iterative algorithm for this class of problems is developed. This new proposal is obtained by combining the Conjugate Gradient Method (CGM) with the Boundary Element Method (BEM) and Multiple Reciprocity Method (MRM). The local error estimates based on the stability of this scheme in the H2 norm, L2 norm and L∞ norm are obtained. Finally, the numerical results on a test case show that this method is correct and feasible. 相似文献