二维Fredholm积分方程Nystrom方法的渐近展开及其外推

本文讨论了求解二维第二类Ｆｒｅｄｈｏｌｍ积分方程的Ｎｙｓｔｒｏｍ方法，得到了数值解的逐项渐近展开，从而可进行Ｒｉｃｈａｒｄｓｏｎ外推，提高数值解的精度。     

二维非线性Volterra积分方程数值解的渐近展开及其外推

本文讨论了求解二维非线性Ｖｏｌｔｅｒｒａ积分方程的Ｎｙｓｔｒｏｍ方法，得到了数值解的逐项渐近展开。从而可进行Ｒｉｃｈａｒｄｓｏｎ外推，提高数值解的精度。     

Helmholtz方程外边值问题的自然边界元法

本文利用Ｆｏｕｒｉｅｒ展开获得了圆外区域上的Ｈｅｌｍｈｏｌｔｚ方程边值问题的Ｐｏｉｓｓｏｎ积分公式和积分方程，并用Ｇａｌｅｒｋｉｎ法求积分方程的解，导出了刚度矩阵元素的计算公式，讨论了数值技术，给出了变分解的唯一性定理和近似解的误差估计。     

求解二维不可压缩Navier-Stokes方程的混合型微分求积法

微分求积法（ＤＱＭ）能以较少的网格点求得微分方程的高精度数值解,但采用单纯的微分求积法求解二维不可压缩Ｎａｖｉｅｒ＿Ｓｔｏｋｅｓ 方程时,只能对低雷诺数流动获得较好的数值解,当雷诺数较高时会导致数值解不收敛·　为此,提出了一种微分求积法与迎风差分法混合求解二维不可压缩Ｎａｖｉｅｒ＿Ｓｔｏｋｅｓ 方程的预估＿校正数值格式,用伪时间相关算法以较少的网格点获得了较高雷诺数流动的数值解·　作为算例,对１∶１ 和１∶２ 驱动方腔内的流动进行了计算,得到了较好的数值结果·     

非线性单调型Neumann问题的有限元方法

本文讨论了一类非线性单调型Ｎｅｕｍａｎｎ问题的有限元方法。首先，给出这类问题解存在性的一个新证明。其次，基于这一新证明，构造了问题的一个有限逼近格式。最后，应用基于等价极小化问题的有限元数值分析法，得到了线性有限元逼近解的收敛性结果和误差估计。另外，顺便还指出：如果将这一有限元数值分析法类似地应用于非线性单调型Ｄｉｒ－ｉｃｈｌｅｔ问题，那么Ｇｌｏｗｉｎｓｋｉ和Ｍａｒｒｏｃｏ＾［３］的结果可以进一步     

矩形中厚板和夹层板的后屈曲

本文研究了矩形Ｒｅｉｓｓｎｅｒ中厚板和夹层板的后屈曲特性。首先将矩形中厚板和夹层板的基本方程和边界条件表述成统一的无量纲形式。对不同的边界条件，特别是不对称边界条件，文中发展了一种应用于非线性分析的混合Ｆｏｕｒｉｅｒ级数求解新方法，获得了级数形式的精确解。非线性偏微分方程化为无穷元非线性代数方程组，数值计算中截取有限项进行迭代求解。     

二阶非线性常微分方程的正周期解

本文应用Ｋｒａｓｎｏｓｅｌｓｋｉｉ锥映射不动点定理，研究了二阶非线性常微分方程的ω-周期解的存在性，获得了若干正ω-周期解的存在性与多重性结果．     

一般各向异性复合材料层板基体损伤性能衰减研究（II）——分解 …

本文尝试将损伤复合材料层板性能衰减研究扩展到含一般各向异辅层的基体开裂层板，对第（Ｉ）部分提出分解刚度法给出分解刚度值确定方程，完整了开裂层板本构关系解，对（θｍ／９０ｎ）ｓ开裂层板刚度衰减了数值计算并对计算结果进行了讨论。     

一类非线性卷积积分方程振荡性的研究

给出了方程ｚ（ｔ）＋∫Ｋ（ｔ－ｓ）Ｇ（ｓ，ｘ（ｓ），ｘ（ｇ（ｓ）））ｄｓ＝ｆ（ｔ）振荡的充分条件与非振荡解的渐近性以及无界解的振荡性。     

三维Wigner-Poisson方程组的Cauchy问题

考虑三维 Ｗｉｇｎｅｒ－Ｐｏｉｓｓｏｎ方程组的 Ｃａｕｃｈｙ问题，将 ＷＰ问题转化为等价的 Ｓｃｈｒｏｄｉｎｇｅｒ－Ｐｏｉｓｓｏｎ问题．采用有限区域序列上的解的逼近方法，通过对逼近解建立与区域无关的先验估计，证明了 Ｃａｕｃｈｙ问题解的存在性、唯一性和逼近解的收敛性     

Asymptotic Error Expansion for the Nystrom Method of Nonlinear Volterra Integral Equation of the Second Kind

1.IntroductionConsiderthenonlinearVolterraintegraJequationofthesecondkindHere,u(x)isanunknownfunction,f(x)andK(x,t,u)aregivencontinuousfunctionsdefined,respectively,on[a,b1andD={(x,t,u):aSx5b,aSt5x)-oc相似文献   

A New View of the Computational Complexity of IVP for ODE

The cost of solving an initial value problem for ordinary differential equations to accuracy 2 is polynomial in ln. Adaptive step-size control is never theoretically more costly than fixed step-size control, and can be an unbounded factor less costly. These results contradict the standard theory, but are based on more realistic assumptions.     

非线性积分方程迭代配置法的渐近展开及其外推

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Numerical method for solving linear Fredholm fuzzy integral equations of the second kind

In this paper we use parametric form of fuzzy number and convert a linear fuzzy Fredholm integral equation to two linear system of integral equation of the second kind in crisp case. We can use one of the numerical method such as Nystrom and find the approximation solution of the system and hence obtain an approximation for fuzzy solution of the linear fuzzy Fredholm integral equations of the second kind. The proposed method is illustrated by solving some numerical examples.     

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