查询词典 symmetric difference

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

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。

By using Fourier analysis on the capability of resolution,we conclude that CSCD gives higher resolution,with respect to other symmetric finite difference methods.

从定量角度，利用Fou-rier分析方法分析了CSCD格式的分辨率，并同其他中心型差分格式比较，得出CSCD格式有较高的分辨率的结论。

In littler reduced area difference it transformed symmetric shape of a sphere enclosing above and below two smaller spheres into asymmetric shape.

我们通过研究发现，上下对称性确实被打破，但只在约化面积差较大时转化到胃形泡；在约化面积差较小时，则转化到上下不对称的双内陷形状。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。