迭代计算

Through calculating the fundus of the null space of matrix A in the constraint,there exists at least one feasible descent direction at every nonstationary point and every iterate generated by the methods is feasible so long as the initial iterate is feasible.

通过计算约束条件中矩阵A的零空间的基底，使得在每一个非稳定点处至少存在一个可行的下降方向，并且在初始点是可行点的条件下，该算法产生的每一个迭代点都是可行点。

The error growth of numerical method grows linearly with the stage of iterated matrix. A sufficient condition of bounded stability for linear θ-method is proved.

证明了数值方法的计算误差是随着迭代矩阵的级数线性增长的，又进一步给出了线性θ-方法有界稳定的一个充分条件。

On the basis of the fundamental theory of information optics, the Fourier transform and an iterative approach are used to calculate and analyze the point image of an optical imaging system the Point Spread Function (PSF of light intensity, to retrieve the phase of imaging system and then to obtain the wave font of the optical system.

基于信息光学基础理论，采用傅里叶变换和迭代算法计算分析了光学成像系统的星点图像（光强点扩散函数，PSF），实现了对光学成像系统位相的复原，获得了波像差信息。

The methods most in use to the solution of the problem with unacceptable frequency bands: one is a mathematical programming or optimum criterion method; the other is structure matrix perturbation.

前者的局限性是结构重分析次数多，计算时间长；后者虽可在一定程度上避免重分析，但其迭代步长难以确定。

Msmodel is formulated with the relative displacement and the contact press direCtiyin the orthogonal coordinate syStem, without introducing the slip angle asvariable and transforming the variab1e to the polar coordinate system.

在工程实际中得到大量应用的二维摩擦接触问题迭代法，贴近力学直观，无须引入额外变量，无须计算导数矩阵，被工程界所熟悉。

The former is an iterative method, and quaternion was utilized to simplify the matrix orthogonalization procedure.

改进的单点估计算法是一种迭代算法，它计算简单，收敛速度快，同时由于采用四元数表示姿态矩阵，简化了矩阵的正交化过程。

This paper improves the iterative format of the symmetric successive overrelaxation PCG method,as a result the computation is reduced by 8%～50%.This paper also presents some key subroutines for application of the SSOR PCG method to the solution of finite element equations.

本文改进了对称逐步超松驰预处理共轭梯度法的迭代格式，可节省计算量8％～50％，并给出应用SSORPCG法求解有限元方程组时的几个关键子程序。

In this chapter, we show that Perron complements of N_0~2-matrices are N_0~2-matrices. We also demonstrate the Perron complements of inverse N_0~1-matrices are inverse N_0~1-matrices with certain restriction.

第四章研究非严格广义双对角占优矩阵的Schur余的性质，对角占优矩阵是数值计算中经常遇到的一类矩阵，它的Schur余可应用于迭代法的构造。

The forward-backward methodology is combined with the fast multipole method and the iterative physical optics to improve convergence and computational efficiency.

详细推导了快速多极子方法结合迭代物理光学法和阻抗边界条件的混合计算公式。

Meanwhile, we also provide methods for computing the weighted polar decomposition, and study error bounds for the approximate generalized positive semidefinite polar factor and perturbation bounds for weighted polar decomposition in various norms.

针对这个新的矩阵分解，我们证明了其唯一性定理，给出了其唯一性条件，讨论了其极因子的最佳逼近性质；同时，我们还探讨了矩阵加权极分解的计算问题，研究了由迭代算法引起的极因子的误差界，极因子在各种范数下的各种形式的扰动界等。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。