Error estimates of H 1-Galerkin mixed finite element method for Schrödinger equation

An H^1-Galerkin mixed finite element method is discussed for a class of second order SchrSdinger equation. Optimal error estimates of semidiscrete schemes are derived for problems in one space dimension. At the same time, optimal error estimates are derived for fully discrete schemes. And it is showed that the H1-Galerkin mixed finite element approximations have the same rate of convergence as in the classical mixed finite element methods without requiring the LBB consistency condition.     

双曲型积分微分方程H~1-Galerkin混合元法的误差估计

本文用H1-Galerkin混合有限元法分析了基于带有记忆项的多孔介质中的对流问题的数学模型,即双曲型积分微分方程．我们得到了在一维情况下函数和它梯度的最优阶误差估计, 并且由此推广到二维和三维情况下,得到了和用传统的混合元方法相同的收敛阶数,而且不用验证满足LBB相容性条件．     

伪双曲型方程的一个H1-Galerkin非协调混合元格式

讨论了一类伪双曲型方程的一个H1-Galerkin非协调混合有限元方法.利用插值算子的特殊性质,在半离散和全离散格式下,得到了与传统混合有限元相同的误差估计且不需要满足LBB条件.     

伪双曲型积分-微分方程的H~1-Galerkin混合元法误差估计

<正>1引言考虑如下一类具有Lipschitz连续边界(?)Ω的凸有界区域Ω上的伪双曲型积分微分方程其中Ω(?)R~d,(d=1,2,3)J=(0,T],对于固定的T,0T∞,函数0a_0≤a(x,t)≤     

四阶抛物偏微分方程的H1-Galerkin混合元方法及数值模拟

到目前为止, H¹-Galerkin 混合有限元方法研究的问题仅局限于二阶发展方程. 然而对于高阶发展方程, 特别是重要的四阶发展方程问题的研究却没有出现. 本文首次提出四阶发展方程的H¹-Galerkin 混合有限元方法, 为了给出理论分析的需要, 我们考虑四阶抛物型发展方程. 通过引进三个适当的中间辅助变量, 形成四个一阶方程组成的方程组系统, 提出四阶抛物型方程的H¹-Galerkin 混合有限元方法. 得到了一维情形下的半离散和全离散格式的最优收敛阶误差估计和多维情形的半离散格式误差估计, 并采用迭代方法证明了全离散格式的稳定性. 最后, 通过数值例子验证了提出算法的可行性. 在一维情况下我们能够同时得到未知纯量函数、一阶导数、负二阶导数和负三阶导数的最优逼近解, 这一点是以往混合元方法所不能得到的.     

强阻尼波动方程的H1-Galerkin混合有限元超收敛分析

研究了强阻尼波动方程的H¹-Galerkin混合有限元方法的超收敛性. 借助于协调线性三角形元已有的分析估计式, 直接利用插值算子代替原始变量 u 的 Ritz 投影和应力变量 p 的 Ritz-Volterra 投影,对半离散和全离散格式, 得到了u在 H¹(Ω) 模和 p 在 H(div;Ω) 模意义下比以往文献高一阶的超逼近和超收敛结果.     

阻尼Sine-Gordon方程的H1-Galerkin混合元方法数值解

利用H1-Galerkin混合有限元方法讨论阻尼Sine-Gordon方程,得到一维情况下半离散和全离散格式的最优阶误差估计,并且推广应用到二维和三维情况,而且不用验证LBB相容性条件.     

A new mixed scheme based on variation of constants for Sobolev equation with nonlinear convection term

A new mixed scheme which combines the variation of constants and the H ¹-Galerkin mixed finite element method is constructed for nonlinear Sobolev equation with nonlinear convection term. Optimal error estimates are derived for both semidiscrete and fully discrete schemes. Finally, some numerical results are given to confirm the theoretical analysis of the proposed method.     

Two temporal second-order <Emphasis Type="Italic">H</Emphasis><Superscript>1</Superscript>-Galerkin mixed finite element schemes for distributed-order fractional sub-diffusion equations

In this paper, a special point is found for the interpolation approximation of the distributed order fractional derivatives to achieve at least second-order accuracy. Then, two H¹-Galerkin mixed finite element schemes combined with the higher accurate interpolation approximation are introduced and analyzed to solve the distributed order fractional sub-diffusion equations. The stable results, which just depend on initial value and source item, are derived. Some a priori estimates with optimal order of convergence both for the unknown function and its flux are established rigorously. It is shown that the H¹-Galerkin mixed finite element approximations have the same rates of the convergence as in the classical mixed finite element method, but without LBB consistency condition and quasiuniformity requirement on the finite element mesh. Finally, some numerical experiments are presented to show the efficiency and accuracy of H¹-Galerkin mixed finite element schemes.     

四阶强阻尼波方程的新混合元方法

构造半线性四阶强阻尼波动方程的新H1-Galerkin混合有限元方法,得到一维情况下半离散和全离散格式最优收敛阶误差估计,并且推广到二维和三维情况,不用验证LBB相容性条件.     

电报方程H~1-Galerkin非协调混合有限元分析

主要研究一类电报方程的H~1-Galerkin非协调混合有限元方法,在任意四边形网格剖分下,其逼近空间分别取为类Wilson元与双线性Q_1元,在不需要满足LBB相容性条件及不采用传统的Ritz投影的情况下,得到了与常规有限元方法相同的L~2-模和H~1-模的误差估计,进一步拓展了H~1-Galerkin混合有限元和类Wilson元的应用范围.     

半线性Sobolev方程的H~1-Galerkin混合有限元方法

利用H~1-Galerkin混合有限元方法研究了一维半线性Sobolev方程,得到了半离散解的最优阶误差估计,优点是不需验证LBB相容性条件.     

热传导方程一个新的H~1-Galerkin非协调混合有限元格式

对热传导方程提出了一个新的H~1-Galerkin非协调混合有限元格式,其逼近空间不需满足LBB相容性条件,且在不引进传统的Rutz投影的情况下,得到了与以往协调有限元方法相同的L~2-模和H~1-模的误差估计.     

广义神经传播方程的一种修正混合有限元方法的误差分析

利用修正的H~1-Galerkin混合有限元方法研究了广义神经传播方程,论证了其半离散解的存在唯一性,得到了半离散解的最优阶误差估计,该方法的优点是不需验证LBB相容性条件.     

Nonconforming <Emphasis Type="Italic">H</Emphasis><Superscript>1</Superscript>-Galerkin mixed FEM for Sobolev equations on anisotropic meshes

A nonconforming H^1-Calerkin mixed finite element method is analyzed for Sobolev equations on anisotropic meshes. The error estimates are obtained without using Ritz-Volterra projection.     

Higher order fully discrete scheme combined withH 1-Galerkin mixed finite element method for semilinear reaction-diffusion equations

We first apply a first order splitting to a semilinear reaction-diffusion equation and then discretize the resulting system by anH ¹-Galerkin mixed finite element method in space. This semidiscrete method yields a system of differential algebraic equations (DAEs) ofindex one. Apriori error estimates for semidiscrete scheme are derived for both differential as well as algebraic components. For fully discretization, an implicit Runge-Kutta (IRK) methods is applied to the temporal direction and the error estimates are discussed for both components. Finally, we conclude the paper with a numerical example.     

A posteriori error estimates for H 1-Galerkin mixed finite-element method for parabolic problems

The purpose of this article is to derive a posteriori error estimates for the H ¹-Galerkin mixed finite element method for parabolic problems. We study both semidiscrete and fully discrete a posteriori error analyses using standard energy argument. A fully discrete a posteriori error analysis based on the backward Euler method is analysed and upper bounds for the errors are derived. The estimators yield upper bounds for the errors which are global in space and time. Our analysis is based on residual approach and the estimators are free from edge residuals.     

粘弹性波动方程的H~1-Galerkin混合有限元方法误差估计(英文)

H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and uniqueness of semidiscrete solutions are derived for problems in one space dimension.And the methods don＇t require the LBB condition.     

A new mixed finite element method for Burgers’ equation

In this paper, anH ¹-Galerkin mixed finite element method is used to approximate the solution as well as the flux of Burgers’ equation. Error estimates have been derived. The results of the numerical experiment show the efficacy of the mixed method and justifies the theoretical results obtained in the paper.     

非线性双曲型方程的变网格有限元法

对一类非线性双曲型方程给出了两种变网格有限元逼近格式 .在一定条件下 ,得到了最优 H 1模误差估计