查询词典 iteration loop

The Schur subspace iteration method is applied for the dynamic characteristic analysis of damped structure vibration system and coupled fluid－structure system. This method avoids complex computation and has good numerical stability. A accelerated technique and a pre－process method for the system matrix are suggested to improve the computational efficiency. The generalized uncoupled equation is obtained from the Schur matrix and a back substitution scheme of response computaton is developed.

第三部分将非对称特征值问题的Schur子空间迭代法应用于非经典阻尼结构振动系统和流固耦合系统的特征值分析，建立了相应的具体算法，并给出了用以提高迭代收敛速度的迭代加速和矩阵预处理等实用技术；利用Schur矩阵的结构特点，推导了系统方程的动力解耦形式，给出了响应计算的回代求解格式。

Not only is the method applied in this paper better to solve the iteration between unsteady convection and conduction and the boundary condition problem, but also is a developmental application on forward and backward difference of windward scheme under unsteady condition.

不仅较好地解决了对流换热和导热的迭代求解和边界条件的处理问题，还将迎风格式的向前和向后差分发展性地应用于非稳态求解过程。

This thesis consists of two parts. The first one was that boundary value problem was discrete with five point difference method. Three kinds of memory formats were studied, which were full matrix, half band width and row compress sparse. Full matrix memory format and half band width memory format first was contrasted. The results show that half band width has efficiency in space. Then the algebraic system of finite element method was solved by Gauss-Seidel iteration method to popular row compress sparse memory format.

本论文由两部分组成，第1部分针对边值问题，用5点差分格式进行离散，并对离散矩阵这类大型稀疏矩阵，研究了系数矩阵的3种存储格式的优劣，即：满矩阵存储格式、半带宽存储格式和按行压缩稀疏存储格式，首先我们将满矩阵存储方式和半带宽存储格式进行了对比，迭代法的数值实验表明：利用半带宽存储的矩阵在空间运算方面具有高效性；然后针对目前数值实验中流行的按行压缩稀疏存储格式，实现了有限元离散代数系统的迭代法的求解。

In this paper, an extended divide and conquer algorithm is intended proposed, which is for solving the real symmetric band generalized eigenvalue problem under distributing environment Eigenvalue partition theorem is presented and proved Based on divide and conquer by extension, this algorithm computes generalized eigenpaires of symmetric band matrix pencil by bisection and generalized Rayleigh quotient iteration Theoretic analysis and numerical results show that this algorithm is better than the classic software package LAPACK when bandwidth is small and the scale is large Combined with multisection, which has good parallelism, it got good effects under distributed environments

提出了分布式环境下计算对称带状广义特征值问题的一种扩展分治算法，给出了特征值分割定理及其证明算法在扩展分治的基础上，利用二分压缩结合广义Rayleigh商迭代计算广义特征对理论分析和数值实验表明，对于窄带宽大规模的广义特征值问题，该分治算法明显优于LAPACK软件包结合并行性好的多分法，在分布式环境下获得了很好的并行效果1 引言本文研究了对称带状广义特征值问题Ax =λBx ( 1)的并行计算，其中，A ，B均为半带宽为r的n阶实对称带状矩阵且其中之一是正定的本文总假设B是正定的求解此问题有两种传统方法，第1种方法是通过计算矩阵B的Cholesky分解，将问题( 1)转化为标准特征值问题[1～3] ，进一步

In order to get the exact value of the Hopf bifurcation point, we discuss the discrete version of the integro-differential equation, and use the approximation parameter as the initial value of the Newton iteration method.

为了得到Hopf参数的精确值，进一步讨论了延迟积分－微分方程的离散形式，利用Newton迭代法，得到了参数的逼近值。

Because the derivation of the extended system has a block lower triangular form, the method of splitting iteration is applied to compute simple bifurcation point, not only computational work is reduced, but also local quadratic convergence is achieved.

由于所构造的扩充系统的导数具有分块下三角形式，采用分块迭代的方法进行数值求解，不仅减少了计算量，而且是二次收敛的，从而为Navier-Stokes方程非退化简单分歧点的数值逼近提供了有效的算法。

Moreover, it makes the coefficient matrix of centralized IPM's linear correction equation a block diagonal bordered matrix, which can be decomposed into the constraints equation on internal variables of independent sub-areas and coupled constraints equation. During each IPM iteration, internal variables and coupled variables are solved distributedly; thus distributed algorithm of multi-area ORPF is implemented.

在此基础上，论文将该线性方程分解为相互独立的子区域内部约束方程和复制节点的耦合约束方程，在每次内点法迭代中分布分块求解内部变量和耦合变量，从而实现多区域无功优化的分布式计算。

A new efficient method of numerical iteration solution to the boundary value problem was put forward.

结合航天飞机和飞马火箭的制导律，进行了制导技术的开发，提出了一种新的基于该控制律的火箭真空段运动的多变量边值问题的有效数值迭代解法。

A new particle swarm optimization, PSO with bounded mutation operator, was developed. In contrast to the original PSO, in this algorithm, PSO with bounded mutation operator would make the particles redistributed cquably close to boundary when place of particle exceeds feasible region during iteration.

提出了一种新的粒子群优化算法——带边界变异的PSO，其原理是：在迭代的过程中，当粒子的位置超出可行域时，带边界变异的PSO让粒子的位置重新均匀分布在边界附近；当粒子的速度超出可行域时，则使其均匀分布到整个可行区间，而不是像原始PS0那样在这2种情况下都只是简单地取边界值。

An self-adaptive multistep integration procedure in conjunction with local iteration and radial return is employed in numerical implementation of the bounding surface model .

详细分析边界面模型，采用自适应多步积分、局部迭代和射线回退相结合的积分方法，给出边界面本构关系的数值实现过程。

The statistical analysis of this large set of mutations has led us to propose a diagnostic strategy that should help with the molecular work-up of optic neuropathies.

这一大系列基因突变的统计学分析引导我们提出一个诊断策略，可以帮助我们对视神经病变进行分子学的诊断检查。

The results show that the pipe grouting changes the mechanical parameters of surrounding rocks to achieve the security of engineering objectives by reinforcing surrounding rocks and bolcking the water.

研究表明：小导管注浆一方面改变了围岩的力学参数，另一方面利用浆液的固结特性可以实现堵水和加固围岩的工程目标，使隧道在开挖过程中的安全得到保障。