查询词典 iteration method

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。

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。

If the Landweber method and pre-iteration method were convergent, the residue sequence would be monotone decreasing. By analyzing the convergence, the fact is demonstrated that for the severe ill-conditioned matrix of sensitivity coefficient, because of the limitation of the precision of the computer, the residue sequence is not monotone decreasing; thereby the reconstruction images diverge from the true distribution of the conductivity. So the generalized inverse method with threshold is established and the selection way of the regularization parameter is presented, by which the better images are reconstructed.

Landweber法和预迭代法收敛，则其残差序列单调递减，通过对它们的收敛性进行分析，证实对于病态性严重的灵敏度系数矩阵，由于受计算精度的限制，迭代过程中的残差序列不再单调递减，从而导致重建图象偏离实际电导率分布，因此作者建立了带阈值的广义逆算法，提出了规则化参数选择方法，获得了较好的图象重建质量。

We analyse and compare the traditional timemarching method, the fixed point iteration method, Chan, Chan and Zhou proposed such an approach using the Newton method combined with continuation and the primal-dual method.

本文对传统的时间依赖方法，不动点迭代法，原始对偶方法，Zhou，Zhou和Chan提出的牛顿法与延拓法相结合的方法进行了比较分析。

According to the space domain iteration method of the Fredholm integral equation of the first kind, the wave number domain iteration formula is deduced for calculating the wave spectrum of the potential field on a lower horizontal plane.

根据第一类Fredholm积分方程的空间域迭代解法，推导出计算向下延拓水平面上位场波谱的波数域迭代公式。

It is difficult to solve the optimal iteration step and Lagrange multiplier in the gradient optimal power flow solutions. The saddle node iteration method was applied to solve the above problems based on a certain supposition.

在梯度法最优潮流的求解过程中，确定不等式约束的拉格朗日乘子以及求取最优步长等比较困难，文中在采取一定假设的基础上，运用鞍点迭代算法进行上述问题的求解。

This idea comes from the appearance of the curse of dimension in computational process, for example, in Markov decision processes, its not practical for improving policy computation using the general policy iteration or value iteration method.

当系统的计算出现维数灾难时，比如在Markov决策过程的求解问题中，如果系统的动作空间非常之大，那么利用一般的策略递归算法或值递归算法，来进行策略的改进计算是不实际的。

Schur-Rayleigh-Ritz accelerated subspace iteration method: Schur-Rayleigh-Ritz accelerated subspace iteration method was applied to the gyroscopic eigenvalue problem.

2Schur-Rayleigh-Ritz加速的子空间迭代法将Schur-Rayleigh-Ritz加速的子空间迭代法应用于陀螺特征值问题。

The mathematical model of complex countercurrent multi-effect evaporation with condensed water flash is established, which aims at minimum annual cost (including cost of fresh vapor, vacuum pump power, evaporator, maintenance and depreciation).Based on such decisive variables as the pressure of fresh vapor, the pressure of condenser and heat-transfer mean temperature difference of vari-effect,the model is solved by the complex method,Lagrangian multiplier method, iteration method and matrix method.The practical example indicates that the influence of the pressure of fresh vapor, the pressure of condenser and flash of condensed water on the optimum design results is notable.

建立了带有冷凝水闪蒸的复杂逆流多效蒸发系统优化设计的数学模型，该模型以整个蒸发系统的年总费用(包括加热蒸汽年费用、真空泵年动力费用以及蒸发器和辅助设备的年折旧维修费用等)最小为优化目标，以生蒸汽压力、冷凝器真空度及各效有效传热温度差为决策变量，提出一种新算法———复合形法结合Lagrangian乘子法、迭代法和矩阵法求解模型。

The downward continuations are made by the iteration method and the FFT for a model and practical data, respectively. The effect of the iteration method is much better than the FFT.

本文用迭代法对模型数据和实际数据进行向下延拓，对比了迭代法与常规的FFT法在位场向下延拓中的效果，迭代法显著优于FFT法。

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。