共查询到20条相似文献,搜索用时 31 毫秒
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本文提出了一个决定横观各向同性材料的独立剪切模量的新的简单方法.给出了数学公式和推导及其解,也提出了测定仪器及其测定结果.本法曾用Green河岩层的油页岩试验过,这种油页岩就是横观各向同性材料.本文结果也和其它近似结果并和声学试验法的结果比较过.本文也用已知剪切模量的材料来校核本文的测定方法. 相似文献
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本文提出一种一般解析方法——空间变量变换法,用以求解任意边界条件下圆柱厚壳自由振动问题.运用本文方法对悬臂圆柱厚壳的自振特性作了计算,计算结果与薄壳理论相应结果及试验值作了比较.理论分析和计算结果表明,本文方法具有很好的收敛性和精确性,可以推广用于分析梁、板、壳的自由振动. 相似文献
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John T. Conway 《Integral Transforms and Special Functions》2018,29(4):269-283
A new method is presented for deriving indefinite integrals involving quotients of special functions. The method combines an integration formula given previously with the recursion relations obeyed by the function. Some additional results are presented using an elementary method, here called reciprocation, which can also be used in combination with the new method to obtain additional quotient integrals. Sample results are given here for Bessel functions, Airy functions, associated Legendre functions and the three complete elliptic integrals. All results given have been numerically checked with Mathematica. 相似文献
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Numerical analysis of a Picard multilevel stabilization of mixed finite volume method for the 2D/3D incompressible flow with large data
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《Numerical Methods for Partial Differential Equations》2018,34(1):30-50
In this article, we develop a branch of nonsingular solutions of a Picard multilevel stabilization of mixed finite volume method for the 2D/3D stationary Navier‐Stokes equations without relying on the unique solution condition. The method presented consists of capturing almost all information of initial problem (the nonlinear problems) on the coarsest mesh and then performs one Picard defect correction (the linear problems) on each subsequent mesh based on previous information thus only solving one large linear systems. What is more, the method presented can results in a better coefficient matrix in the model presented with small viscosity. Theoretical results show that the method presented is derived with the convergence rate of the same order as the corresponding finite volume method/finite element method solving the stationary Navier‐Stokes equations on a fine mesh. Therefore, the method presented is definitely more efficient than the standard finite volume method/finite element method. Finally, numerical experiments clearly show the efficiency of the method presented for solving the stationary Navier‐Stokes equations.© 2017 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 34: 30–50, 2018 相似文献
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Zhiyong Si Yunxia Wang Shishun Li 《Mathematical Methods in the Applied Sciences》2014,37(9):1392-1404
In this paper, a modified characteristics finite element method for the time dependent Navier–Stokes/Darcy problem with the Beavers–Joseph–Saffman interface condition is presented. In this method, the Navier–Stokes/Darcy equation is decoupled into two equations, one is the Navier–Stokes equation, the other is the Darcy equation, and the Navier–Stokes equation is solved by the modified characteristics finite element method. The theory analysis shows that this method has a good convergence property. In order to show the effect of our method, some numerical results was presented. The numerical results show that this method is highly efficient. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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一类各向异性外问题的重叠型区域分解算法 总被引:2,自引:0,他引:2
本文以椭圆外调和问题的自然边界归化为基础,提出了求解各向异性常系数椭圆方程的一种重叠型区域分解算法,并分析了算法的收敛性及收敛速度.理论分析及数值实验表明,该方法对于求解各向异性外问题非常有效. 相似文献
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《Applied Numerical Mathematics》2006,56(10-11):1307-1313
This paper presents a review of the so-called Local Discontinuous Galerkin (LDG) method applied to elliptic problems. The method is presented using a mixed formulation similar to that of the classical mixed finite element method. A summary of the convergence properties is presented. Preliminary theoretical results on super-convergent points are discussed. Numerical experiments of a gradient recovering technique are presented. 相似文献
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Elçin Yusufo?lu 《Applied mathematics and computation》2010,217(7):3591-3595
A numerical method for solving the generalized (retarded or advanced) pantograph equation under initial value conditions is presented. To display the validity and applicability of the numerical method four illustrative examples are presented. The results reveal that this method is very effective and highly promising when compared with other numerical methods, such as Adomian decomposition method, spline methods and Taylor method. 相似文献
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A Bubnov-Galerkin finite element method with quintic B-spline functions taken as element shape and weight functions is presented for the solution of the KdV equation. To demonstrate the accuracy, efficiency and reliability of the method three experiments are undertaken for both the evolution of a single solitary wave and the interaction of two solitary waves. The numerical results are compared with analytical solutions and the numerical results in the literature. It is shown that the method presented is accurate, efficient and can be used at small times when the analytical solution is not known. 相似文献
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线性Poisson-Boltzmann方程的Mortar有限元方法的数值计算 总被引:1,自引:0,他引:1
本文对分子生物物理学中产生的线性Poisson-Boltzmann方程(PBE),给出了Mortar有限元方法的计算过程,数值计算例子表明,与一般的协调有限元方法相比,用Mortar元方法求解此类有间断系数的问题有非常有效的。 相似文献
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We extend the limit optimal partial proxy method to compute second-order sensitivities of financial products with discontinuous or angular payoffs by Monte Carlo simulation. The methodology is optimal in terms of minimizing the variance of the likelihood ratio weight. Applications are presented for both equity and interest-rate products with discontinuous payoff structures. The first-order optimal partial proxy method is also implemented to calculate the Hessians of insurance products with angular payoffs. Numerical results are presented which demonstrate the speed and efficacy of the method. 相似文献
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John T. Conway 《Integral Transforms and Special Functions》2016,27(5):371-384
A substantial number of indefinite integrals are presented for the incomplete elliptic integrals of the first and second kinds. The number of new results presented is about three times the total number to be found in the current literature. These integrals were obtained with a Lagrangian method based on the differential equations which these functions obey. All results have been checked numerically with Mathematica. Similar results for the incomplete elliptic integral of the third kind will be presented separately. 相似文献
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A. V. Berdakchiev 《Mechanics of Composite Materials》1975,11(2):249-253
The problem of a viscoelastic cylinder reinforced with a thin elastic casing with consideration given to a heterogeneous temperature field is presented. The method of numerical solution of the problem is discussed. The results of computation are presented in the form of curves. 相似文献
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In this article, a characteristic finite volume element method is presented for solving air pollution models. The convection term is discretized using the characteristic method and diffusion term is approximated by finite volume element method. Compared with standard finite volume element method, our proposed method is more accurate and efficient, especially suitable to solve convection-dominated problems. The proposed numerical schemes are analyzed for convergence in L 2 norm. Some numerical results are presented to demonstrate the efficiency and accuracy of the method. 相似文献
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本文利用广义投影矩阵,对求解无约束规划的超记忆梯度算法中的参数给出一种新的取值范围以保证得到目标函数的超记忆梯度广义投影下降方向,并与处理任意初始点的方法技巧结合建立求解非线性不等式约束优化问题的一个初始点任意的超记忆梯度广义投影算法,在较弱条件下证明了算法的收敛性.同时给出结合FR,PR,HS共轭梯度参数的超记忆梯度广义投影算法,从而将经典的共轭梯度法推广用于求解约束规划问题.数值例子表明算法是有效的. 相似文献
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提出了一种求解二维Poisson方程的新方法-有限差分-Chebyshev Tau方法,并给出了一些有关的数值结果,结果表明,这一方法是令人满意的,且与其它方法相容。 相似文献
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Aditya Kaushik 《Journal of Difference Equations and Applications》2016,22(9):1307-1324
The convection dominated diffusion problems are studied. Higher order accurate numerical methods are presented for problems in one and two dimensions. The underlying technique utilizes a superposition of given problem into two independent problems. The first one is the reduced problem that refers to the outer or smooth solution. Stretching transformation is used to obtain the second problem for inner layer solution. The method considered for outer or degenerate problems are based on higher order Runge–Kutta methods and upwind finite differences. However, inner problem is solved analytically or asymptotically. The schemes presented are proved to be consistent and stable. Possible extensions to delay differential equations and to nonlinear problems are outlined. Numerical results for several test examples are illustrated and a comparative analysis is presented. It is observed that the method presented is highly accurate and easy to implement. Moreover, the numerical results obtained are not only comparable with the exact solution but also in agreement with the theoretical estimates. 相似文献