查询词典 triangular factorization

This paper analyses the LR factorization of matrix,and improves the algorithm based on recursive algorithm and iteration,and brings forth the developed method of matrix factorization,which accelerates the convergence speed of the factorization.

将方程组系数矩阵的LR分解算法过程加以改进，加入递归算法，使矩阵产生分块。

It turns out that minor prime factorization and determinantal factorization are two interesting special cases of the proposal general factorization.

其中体现出来子式和行列式分解是一般分解方案中两种有趣特殊的。

Two above methods are generalized to tensor product Bézier surfaces and triangular Bézier surfaces, we give two approaches of degree reduction for tensor product Bézier surfaces, each of which reduces a given degree n×m tensor product Bézier surface to a n〓×m〓 one, and two methods of degree reduction for triangular Bézier surfaces, which reduce a given degree n triangular Bézier surface to a degree m one. The explicit formulas of control points for reduced tensor product and triangular Bézier surfaces are obtained respectively.

张量积Bézier曲面的两种降阶方法均可把n×m阶张量积Bézier曲面一次降阶为n〓×m〓阶张量积Bézier曲面；三角Bézier曲面的两种降阶方法均可把n阶三角Bézier曲面一次降阶为m阶三角Bézier曲面，并给出降阶张量积Bézier曲面和降阶三角Bézier曲面控制顶点的显示表示式。

A efficient LU decomposition method is spectral factorization. That is, after the minimum phase correlative function of each array of matrix had be given by a spectral factorization method, all of the functions are arranged in a position according to its former location to get a lower triangular matrix.

谱法LU分解的优点是在对大量具有相同非零结构的矩阵分解时，通过建立包含所有具有不同非零元素的列对应的自相关函数的分解表，使得随后的所有矩阵分解只需通过查表实现。

In this paper, firstly the elimination tree theory is introduced in brief, and the structure of Jacobian matrix is determined by use of symbolic factorization; then by use of sparse vector method each column of lower triangular matrix L and each row of upper triangular matrix U are solved.

介绍了消去树理论，并采用符号因子分解技术确定雅可比矩阵的结构，然后采用稀疏向量法求取L阵的每行和U阵的每列。

Antiplane responses of a scalene triangular hill or structure, an isosceles triangular hill or structure, an isosceles triangular hill with a subsurface cavity to incident SH waves are studied in this paper based on methods of wave function expanding, complex function, moving coordinates and by employing idea of assistant function.

本文在"分区"和辅助函数思想的指导下，综合利用了波函数展开、复变函数、移动坐标三种方法，研究了等腰三角形凸起地形和坝体结构、非等腰三角形凸起地形和坝体结构、浅埋圆孔附近等腰三角形凸起地形等三类问题对SH波的散射。

A third order ENO finite volume method for hyperbolic conservation laws on unstructured triangular mesh is introduced.In order to obtain the third order accuracy on spatial discretization,a weighted quadratic interpolation is constructed on every triangular mesh.Two point Gauss quadrature formula is also used on each edge of every triangular mesh and the third order TVD Runge-Kutta method is used for time discretization.The numerical order of convergence and the numerical result of a mesh 3 wind tunnel with one step are given.

摘 要 基于双曲型守恒律方程，对非结构三角形网格给出了一种ENO(Essentially Nonoscillatory Scheme)型有限体积格式，方法的主要思想是先对每一个三角形单元构造一个加权的二次插值多项式，而在计算交界面的流通量时采用了两点高斯积分公式以保证格式的整体精度，时间离散采用三阶TVD Runge-Kutta方法。

This is the so-called Duerlite algorithms: from the bottom row of the matrix A do elementary transformation, the diagonal elements into the bottom left of zero, and then show the effect of these lines is equivalent to transform the left by a unit lower triangular matrix, this series of unit lower triangular matrix inverse is the product of L matrices, it is also a unit lower triangular matrix.

这正是所谓的杜尔里特算法：从下至上地对矩阵A做初等行变换，将对角线左下方的元素变成零，然后再证明这些行变换的效果等同于左乘一系列单位下三角矩阵，这一系列单位下三角矩阵的乘积的逆就是L矩阵，它也是一个单位下三角矩阵。

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。

And three special kind of triangular decomposition is introduced. In addition, the calculation of matrix's triangular decomposition and the application on matrix's triangular decomposition are detailedly discussed.

并介绍了三类特殊矩阵的三角分解，且对矩阵三角分解的计算及应用作了较详细的论述。

Fostering the concept of multi-culture firmly and mastering the development of advanced culture correctly are conductive to resisting terrorism, separatism of nationalities and ultraism of religion, which is of great academic theoretical, immediate and profound historical si...

牢固树立多元文化的理念和正确把握先进文化的发展方向，有助于在世界范围内自觉地抵制恐怖主义，民族分裂主义和宗教极端主义。不仅具有重大的学术理论意义，而且也具有重大的现实意义和深远的历史意义。

But if anyone walks in the night, he stumbles, because the light is not in him.

11：10 若在黑夜行走，就必碰跌，因为那光不在他里面。