A Unified Approach to Construct a Class of Daubechies Orthogonal Scaling Functions

We use Lorentz polynomials to give an efficient way to prove Daubechies’ results on the existence of spline type orthogonal scaling functions and to evaluate a class of Daubechies scaling functions in a unified approach.     

On the Accuracy of the Galerkin Method for a Nonlinear Dynamic Beam Equation

The paper deals with the boundary value problem for a nonlinear integro‐differential equation modeling the dynamic state of the Timoshenko beam. To approximate the solution with respect to a spatial variable, the Galerkin method is used, the error of which is estimated. Copyright © 2011 John Wiley & Sons, Ltd.     

基于时滞惯性流形的非线性Galerkin算法

针对Marion-Temam型非线性Galerkin方法可行性强烈依赖于最小解题规模的不足,利用时滞惯性流形的新思想,以二维Navier-Stokes方程为例,给出了该类非线性Galerkin方法的一种改进形式,并证明了改进后的方法在保持原方法优越性的同时,其可行性条件得到了很大的改善,从而,给出的是一种可行的高效稳定算法。     

Convergence Rate of Galerkin Method for a Certain Class of Nonlinear Operator-Differential Equations

In this article, we study a Galerkin method for a nonstationary operator equation with a leading self-adjoint operator A(t) and a subordinate nonlinear operator F. The existence of the strong solutions of the Cauchy problem for differential and approximate equations are proved. New error estimates for the approximate solutions and their derivatives are obtained. The developed method is applied to an initial boundary value problem for a partial differential equation of parabolic type.     

关于K-S方程的非线性伽辽金方法(英文)

该文讨论了关于 K- S方程的伽辽金方法和非线性伽辽金方法的收敛性和 L2 误差估计 ,并得出误差阶一致的结论     

On a class of nonlocal elliptic problems via Galerkin method

In this paper we study existence and uniqueness of solutions to some cases of the following nonlocal elliptic problem:

     

Secondary Buckling Analysis of Thin Rectangular Plates Based on the Wavelet Galerkin Method北大核心CSCD

Application of the wavelet Galerkin method (WGM) to numerical solution of nonlinear buckling problems was studied with classical elastic thin rectangular plates. First, the discretized scheme of the von Kármán equation were introduced, then a simple calculation approach to the Jacobian and Hessian matrices based on the WGM was proposed, and the wavelet discretized scheme-based eigenvalue equation method, the extended equation method and the pseudo arc-length method for nonlinear buckling analysis were discussed. Second, the secondary post-buckling equilibrium paths of elastic thin rectangular plates and the effects of aspect ratios, boundary conditions and bi-directional compression on the mode jumping behaviors, were discussed in detail. Numerical results show that, the WGM possesses good convergence for solving buckling loads on rectangular plates, and the obtained equilibrium paths are in good agreement with those from the stability experiments, the 2-step perturbation method and the nonlinear finite element method. Given the feasibility of combination with different bifurcation computation methods, the WGM makes an efficient spatial discretization method for complex nonlinear stability problems of typical plates and shells. © 2023 Editorial Office of Applied Mathematics and Mechanics. All rights reserved.     

Coupling three-field formulation and meshless mixed Galerkin methods using radial basis functions

In this work, we solve the elliptic partial differential equation by coupling the meshless mixed Galerkin approximation using radial basis function with the three-field domain decomposition method. The formulation has been adopted to increase the efficiency of the numerical technique by decreasing the error and dealing with the ill conditioning of the linear system caused by the radial basis function. Convergence analysis of the coupled technique is treated and numerical results of some solved examples are given at the end of this paper.     

定常Kuramoto-Sivashinsky方程关于非线性伽辽金方法的一个注记

本文讨论了定常Ｋ－Ｓ方程关于伽辽金方法和非线性伽辽金方法的收敛性和最大模估计;对相同模数而言,两者的误差阶完全一致,数值结果表明非线性伽辽金方法同样成功地计算出了Ｋ－Ｓ方程的分歧解,并且在计算时间方面非线性伽辽金方法比伽辽金方法要少得多。     

巧用Lagrange乘数法求一类多元对称函数的条件最值

巧用Lagrange乘数法,将一类多元对称函数的条件最值转化为一元函数的无条件最值,避免了具体求复杂而困难的驻点方程组的解,使问题化难为易.     

基于Rosenbrock型指数积分的一维间断Galerkin有限元方法

提出基于Rosenbrock型指数积分的一维间断Galerkin有限元方法.该方法在空间上使用间断有限元方法离散,在时间上采用Rosenbrock型指数积分方法.这样不仅可以保持空间离散上的高精度,而且继承了指数时间积分方法具有显式大步长时间推进的优点.数值试验的结果表明,对于一维双曲守恒律问题,这种方法是一种有效的数值算法.     

A Galerkin Method for a Gaseous Ignition Model

Our aim is to investigate the existence of solutions to some second order difference equations of monotone type. Theorems 1.1 and 1.2 below are the discrete versions of some existence results due to V. Barbu [1] corresponding to the continuous case.     

关于Kuramoto-Sivashinsky方程的非线性Galerkin方法之注记*

本文致力于讨论求解Kuramoto-Sivashinsky方程的非线性Galerkin方法,我们采用了s_m个小尺度分量作反馈,并给出了收敛性结果,分析了误差估计．结论表明我们的修正方法是十分有效的．     

无单元Galerkin法在热传导中的应用

对热传导问题的微分方程采用无单元Galerkin法进行数值求解.首先,将微分方程用Galerkin加权残量法转化为等效的积分形式.然后,先将时间变量看作参数,对空间变量进行离散化,得到方程的半离散形式,接着,对时间采用向后Euler-Galerkin格式进行离散,得到方程的全离散形式最后,编制MATLAB程序,上机计算...     

Wavelet-Taylor Galerkin Method for the Burgers Equation

In this paper, we propose a wavelet-Taylor Galerkin method for the numerical solution of the Burgers equation. In deriving the computational scheme, Taylor-generalized Euler time discretization is performed prior to wavelet-based Galerkin spatial approximation. The linear system of equations obtained in the process are solved by approximate-factorization-based simple explicit schemes, and the resulting solution is compared with that from regular methods. To deal with transient advection-diffusion situations that evolve toward a convective steady state, a splitting-up strategy is known to be very effective. So the Burgers equation is also solved by a splitting-up method using a wavelet-Taylor Galerkin approach. Here, the advection and diffusion terms in the Burgers equation are separated, and the solution is computed in two phases by appropriate wavelet-Taylor Galerkin schemes. Asymptotic stability of all the proposed schemes is verified, and the L_∞ errors relative to the analytical solution together with the numerical solution are reported. AMS subject classification (2000) 65M70     

Kuramoto-Sivashinsky方程的B样条Galerkin方法

采用显隐结合的方法对微分算子进行时间离散 ,提出了解 Kuramoto-Sivashinsky方程的全离散 B样条 Galerkin方法 ,由此得到了有限元解的最优阶收敛性及稳定性估计 .最后的数值算例以图形的形式体现了此算法的精确度     

An $h$-Adaptive Runge-Kutta Discontinuous Galerkin Method for Hamilton-Jacobi Equations

In [35, 36], we presented an $h$-adaptive Runge-Kutta discontinuous Galerkin method using troubled-cell indicators for solving hyperbolic conservation laws. A tree data structure (binary tree in one dimension and quadtree in two dimensions) is used to aid storage and neighbor finding. Mesh adaptation is achieved by refining the troubled cells and coarsening the untroubled "children". Extensive numerical tests indicate that the proposed $h$-adaptive method is capable of saving the computational cost and enhancing the resolution near the discontinuities. In this paper, we apply this $h$-adaptive method to solve Hamilton-Jacobi equations, with an objective of enhancing the resolution near the discontinuities of the solution derivatives. One- and two-dimensional numerical examples are shown to illustrate the capability of the method.     

小波伽辽金方法应用于变系数波动方程

我们考虑问题K（x）uxx=ua.0＜X〈1，t≥0，其中K（x）≥a≥0，u（0，t）=g，ix（0，t）=0．这是一个不适当的方程，因为当解存在时在边界g上一个小的扰动将对它的解造成很大的改变．我们考虑存在解u（x，·）∈L^2（R）用小波伽辽金方法和Meyer多分辨分析去滤掉高频部分，从而在尺度空间Vj上得到适定的近似解．我们也可以得到问题的准确解与它在Vj上的正交投影之间的误差估计．