查询词典 operation of symmetric difference

A parallel algorithm for certain real symmetric block-tridiagonal linear systems on distributed-memory multicomputers is proposed. This algorithm is based on the block factorization of the coefficient matrix. This algorithm is used to solving the block-tridiagonal linear systems resulted from the finite difference approximation to Poisson's equation with Dirichlet boundary conditions. Then we get a parallel algorithm which speedup tends to linear speedup.

7研究了一类实对称块三对角线性方程组的分布式并行求解，提出了一种基于块矩阵分解的高效分布式并行算法，将其应用于求解带Dirichlet边界条件的Poisson方程导出的块三对角线性方程组，得到加速比趋于线性加速比的分布式并行算法，理论上说，这也是并行算法的理想情况。

This paper is devoted to solving linear saddle point problems, Specifically, We consider nonsymmetric systems, written as usual in block form, where the upper left block is an invertible linear operator with positive definite symmetric part. Such saddle point problems arise, for example, in certain finite element and finite difference discretizations of NavierStokes equations, Oseen equations, and mixed finite element discretization of second order convection-diffusion problems.

中文题名求解鞍点问题的迭代方法副题名外文题名论文作者冯丽红导师曹志浩教授学科专业计算数学研究领域\研究方向学位级别博士学位授予单位复旦大学学位授予日期2002 论文页码总数87页关键词鞍点问题迭代方法网格离散线性方程组馆藏号BSLW /2003 /O241 /15 论文针对鞍点问题的求解分析了一些典型的快速算法。

The elliptic type governing equations, subject to free boundary conditions, have been solved to sutdy the velocity, temperature, and pressure distributions throughout, as well as local Nusselt numbers from 10/sup 2/ to 10/sup 6/ are presented for both symmetric and asymmetric heating cases, and the influence of wall temperature difference ratio, r'/sub T/ on the flow pattern is also considered.

由求解椭圆型统制方程式及利用自由边界处理方法，来计算整个流场的速度，温度和压力分布，以及在板面上之局部纳瑟数。葛拉修数的计算范围为102-106，且包括对称及不对称加热二种情形，尤其是二板温差比。gamma。/sub T/对流场的影响方面。

The truncation error of CSCD is derived and compared with some symmetric finite difference methods having the same order of accuracy,which shows that CSCD has the smallest coefficients in error terms.

从定性角度，得出同阶中心差分格式中，CSCD格式的截断误差系数最小的结论。

In the first part we consider the convergence and stability of finite difference scheme for Landau-Lifshitz equation in one dimensions space and 2d radial symmetric Landau-Lifshitz equation.

在第一部分，我们研究一维Landau-Lifshitz方程非齐次边值问题和二维柱对称Landau-Lifshitz方程Neumann边值问题的有限差分格式。

In this paper, the finite difference method for the homogenous initial boundary value problem of symmetric regularized long-wave equation is considered.

本文考虑了具有齐次边界条件的对称正则长波方程的有限差分方法。

Keywords: Large sets of Kirkman triple system; transitive resolvable idempotent symmetric quasigroup; almost difference set; defference sets pair

中文关键词： Kirkman三元系大集，可迁可分解幂等对称拟群，几乎差集，差集偶

Liouville"s Theorem on entire functions is proposed as a proving method for theta function identities. Several identities are exemplified, such as the quintuple and septuple product identities; four symmetric difference identities related to the Ramanujan"s congruence modulo 11 on the partition function; as well as two theta function identities on the Rogers-Ramanujan functions G and H.

作者提出利用Liouville定理作为证明theta函数恒等式的基本方法，并以Watson五重积，Hirschhorn七重积恒等式，四个与分拆函数中Ramanujan的模11同余有关的对称差恒等式，以及两个与Rogers-Ramanujan函数G，H有关的theta函数恒等式为范例，论证这种方法的有效性。

In Chapter 4, a symmetric triangular partitioned secant method for solving large scale sparse unconstrained optimization problems is constructed, which is a combination of a secant method and a finite difference method, and depends on a consistent partition of the columns of the lower triangular part of the Hessian matrix; it reduces the number of gradient evaluations required by Powell and Toints algorithm (the indirect lower triangular substitution algorithm) by one at every iterative step.

此算法是基于稀疏Hesse阵的下三角部分的列的相容分划的基础上建立起来的，把割线法和有限差分法有机的结合在了一起，在每次迭代中，把由Powell和Toint的算法所需要的梯度赋值次数减少了一。

Inspired by Chans double series representation formula of_∞~(10), the author constructs a new difference equation on quintuple products, which leads to clarification on the four symmetric differences that are equivalent in pairs.

受Chan得到的_∞~(10)的二重级数表示公式的启发，作者构造一个新的关于五重积的差分公式，并澄清迄今为止所出现的四个对称差恒等式之间成对等价的关系。

He studied their excrement for evidence of livestock hair.

他为家畜毛的证据研究他们的粪便。

Loneliness is not grounds for deportation, deportation of the people are not all lonely people.

寂寞也不是放逐的理由，放逐的人也并不都是孤独的人。