定常Navier—Stokes方程的Petrov—Galerkin方法

研究了定常Navier－Stokes方程的四种Petrov－Galerkin有限元方法：PG1，PG2，SD和GLS．它们都是稳定的，避免了经典混合方法中必要的Babuska－Brezzi条件．给出了各种方法有限元解的存在性、唯一性和唯一解的误差估计．     

双诱导映射下的L-Fuzzy子环上的L-Fuzzy模

给出了L－Fuzzy子环的L－Fuzzy模概念，给出了它的若干刻画，并证明了在双诱导映射及逆映射下L－Fuzzy子环上的L－Fuzzy模仍L－Fuzzy环上的L－Fuzzy模。     

二维N－S方程的Fourier非线性Galerkin方法

本文对周期边界条件Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程，证明了其Ｆｏｕｒｉｅｒ非线性Ｇａｌｅｒｋｉｎ逼近解的存在唯一性，同时给出了逼近解的误差估计．     

半环上Fuzzy k-理想的再定义

本文中，给出Fuzzy k－理想的新的概念作为半环上k－理想的新的模糊化概念，研究了半环同态下的Fuzzy k－理想的象及逆象的有关性质，并给出了非负整数半环N的Fuzzy k－理想的构造。     

Nassrallah-Rahman积分的一个新证明

应用关于ｑ－微分算子的Ｌｅｉｂｎｉｚ公式证明了关于ｑ－微分算子的两个恒等式．利用这些恒等式及ｑ－级数的一些求和公式给出了Ｎａｓｒａｌａｈ－Ｒａｈｍａｎ积分的一个新证明，进而给出了关于ｑ－级数８Φ７的积分表示的一个简易推导     

关于左π—正则po—半群

本文在po-半群和半群中引起一致π－半素族的概念，并给出了左π－正则po-半群的若干刻划，这些刻划推广了N.Kehayopulu在文[1]中给出的一些结果。     

关于kr-空间与k-空间

本文给出了具有局部可数闭ｋ－网的ｋｒ－空间成为ｋ－空间的一个充要条件，此结果给林寿提出的问题作了一个回答。     

准-Groebner基的计算

本文通过定义S－多项式，给出了系数环是整环的多项式中理想的准－Groebner基的一个算法，并据此给出了计算该理想极大无关变元组和维数的一种方法。     

利用α-样条函数插值及其优化

首先给出了α－样条函数的概念，并给出了α－样条函数的性质，然后讨论了利用α－样条函数进行插值的问题，得到了α－样条插值函数的存在唯一性定理；并给出了误差分析及收敛性，在此基础上还给出了最优α－样条插值函数的存在性定理与数值求法及例子。     

BCI-代数的Fuzzy a-理想

本文的目的是引进PCI－代数的fuzzy α-理想的概念与探讨它的性质，给出了fuzzy α-理想的特征与Meng‘s扩张定理，讨论了BCI－代数中fuzzy α-理想，fuzzy q-理想与fuzzy p-理想之间的关系，从而得到一个BCI－代数的fuzzy子集是fuzzy α-理想当且仅当它是fuzzy q-理想与fuzzy p-理想。利用fuzzy α-理想与fuzzy p-理想分别刻画了结合BCI－代数与p-半单BCI－代数。此外，亦给出了fuzzy α-理想的其他性质。     

Comparison between the convergence rates of the Chebyshev method and the related (2,2)‐step methods

An optimal Chebyshev method for solving A x = b , where all the eigenvalues of the real and non‐symmetric matrix A are located in the open right half plane, is dependent on an optimal ellips∂Ω^* such that the spectrum of A is contrained in Ω^*, the closed interior of the ellipse. The relationship between the convergence rates of the Chebyshev method and the closely related (2,2)‐step iterative methods are studied. (2,2)‐step iterative methods are faster than an optimal Chebyshev method under certain conditions. A numerical example illustrates such an improvement of a (2,2)‐step iterative method. Copyright © 2000 John Wiley & Sons, Ltd.     

Feasible Interior Methods Using Slacks for Nonlinear Optimization

A slack-based feasible interior point method is described which can be derived as a modification of infeasible methods. The modification is minor for most line search methods, but trust region methods require special attention. It is shown how the Cauchy point, which is often computed in trust region methods, must be modified so that the feasible method is effective for problems containing both equality and inequality constraints. The relationship between slack-based methods and traditional feasible methods is discussed. Numerical results using the KNITRO package show the relative performance of feasible versus infeasible interior point methods.     

一类奇性积分方程的多尺度配置快速算法

This paper develops fast multiscale collocation methods for a class of Fredholm integral equations of the second kind with singular kernels. A truncation strategy for the coefficient matrix of the corresponding discrete system is proposed, which forms a basis for fast algorithms. The convergence, stability and computational complexity of these algorithms are analyzed.     

On minimum configuration Rosenbrock methods

A new structure is proposed for Rosenbrock methods for solving stiff ordinary differential equations, which facilitates the development of minimum configuration processes (minimum computational work per step). A fourth order process is described.     

大范围求解非线性方程组的指数同伦法

为了解决关于奇异的非线性方程组求根问题,提出了一种由同伦算法推出大范围收敛的连续型方法-指数同伦法,构造了一类指数同伦方程,克服了Jacobi矩阵的奇异,分析了指数同伦方     

Recent trends in random number and random vector generation

A survey of recent work in the areas of uniform pseudorandom number and uniform pseudorandom vector generation is presented. The emphasis is on methods for which a detailed theory is available. A progress report on the construction of quasirandom points for efficient multidimensional numerical integration is also given.     

一个共轭梯度方法全局收敛性的判别准则

本文建立了一个共轭梯度方法全局收敛性的判别准则,基于这一准则证明了一类三参数共轭梯度法的全局收敛性及DY方法的一个变形的全局收敛性.     

ORDERING IN AUTOMATED THEOREMPROVING OF DIFFERENTIAL GEOMETRY

1.BackgroundMom1979,WuWentsunbeganthestudyofautomatedtheoremprovingindifferentialgeometry[1].Inhismethod,thehypotheses,representedbydifferentialpolynomials,aretriangulatedaccordingtoanorderofthevariablesinthepolynomials;theconclusionisprovedbythetriangulatedresultcalledcharacteristicset.Wuusedelement-basedorderingmethodwhichcanbeillustratedbythisexample'LettingxKybetwosmoothfunctionsofthesamevariable,thenxKX'KX"K'Ky'y,Ky"'.ThisorderisthefoundationofWu'seliminationprinciple.However,a…     

Dual reciprocity hybrid radial boundary node method for the analysis of Kirchhoff plates

A meshless method of dual reciprocity hybrid radial boundary node method (DHRBNM) for the analysis of arbitrary Kirchhoff plates is presented, which combines the advantageous properties of meshless method, radial point interpolation method (RPIM) and BEM. The solution in present method comprises two parts, i.e., the complementary solution and the particular solution. The complementary solution is solved by hybrid radial boundary node method (HRBNM), in which a three-field interpolation scheme is employed, and the boundary variables are approximated by RPIM, which is applied instead of moving least square (MLS) and obtains the Kronecker’s delta property where the traditional HBNM does not satisfy. The internal variables are interpolated by two groups of symmetric fundamental solutions. Based on those, a hybrid displacement variational principle for Kirchhoff plates is developed, and a meshless method of HRBNM for solving biharmonic problems is obtained, by which the complementary solution can be solved.     

New convergence estimates for multilevel algorithms for finite-element approximations

New convergence estimates are established for some multilevel algorithms for finite-element methods applied to elliptic problems with jump coefficients. A uniform rate of convergence is derived if the coefficient has only one jump interface. If the coefficient has multi-jump interfaces which meet at only one interior point in the domain, the convergence rate is bounded by 1−(CJ)⁻¹, where J is the number of levels and C is a constant independent of the jump.