查询词典 method of iteration

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。

Based on the isoperimetric graph partitioning method, we propose several practical segmentation algorithms. The first is the iterative two-way cut method which can segment an image into pieces with particular characteristics each other by iteration. The second is simultaneous K-way cut method which divides the image into K parts synchronously. The last is an interactive method separating objects of interest from the background by the user's input specifying the object of interest manually.

基于等周分割方法，我们提出了几种实用的分割算法：第一种是迭代2分方法，它通过迭代的方法将图像分割成各具特征的小区域；第二种是同时直接K分法，同时将图像分割成K个部分；最后一种方法是交互分割法，它依赖人工输入来指定所要分割的感兴趣目标，将图像目标从背景中分离出来。

This paper proposed an implicit technique based on the Jacobi's iteration method. The theoretical demonstration and analysis show that the proposed method meet both the real-time and the stability requirement well. The new method which can update stably the state of n mass points with the time complexity of O has great advantages over the existing implicit integration methods.

本文提出了一种基於雅可比迭代法的隐式数值积分算法，通过理论证明和分析，该算法稳定地更新n个质点的状态所需时间复杂度为O，较已有的隐式积分算法有了很大的改进。

Based on the concept of the non-proportional damping which may be divided into the proportional part for dissipation of energy and the nonproportional part for transformation of energy, a new modal superposition pseudo-force method is presented if the approximate decoupling method is not suitable. In this method the coupled modal equations are solved by iteration in which the coupling terms are treated as pseudo-force and set to the right side of the equations.

在不能进行近似解耦分析时，基于非比例阻尼可分为耗散能量的比例部分和转换能量的非比例部分这种概念，建立了一种拟力实模态叠加法，即把正则化的耦合模态方程中代表非比例阻尼部分的耦合项作为虚力，放到方程的右端，再运用迭代法求解。

In this thesis, the methods for solving eigenvalue problems and conventional reanalysis methods are studied firstly. Then, a new reanalysis method for real modal reanalysis of structures subjected to topological modification with added degrees of freedom is presented. This method is composed of the single step perturbation method and the Rayleigh-quotient iteration. The numerical examples show that this reanalysis method is very effective and high-quality.

本文首先在对常规的特征值数值求解方法和重分析方法研究的基础上，针对实模态的自由度增加的结构拓扑修改重分析，提出了一种新方法，该方法由于结合了单步摄动法和瑞利商逆迭代法两者的优点，应当是一种比较理想的重分析方法，算例的数值结果也有力的验证了该方法确实是一种高精度、十分有效的实模态重分析方法。

By introducing the nonlinear complementarity problem function, the Karush-Kuhn-Tucker conditions of OPF model are transformed equivalently into a set of semismooth nonlinear algebraic equations. Then the set of semismooth equations can be solved by a semismooth L-M method based on the subdifferential. The method belongs to Newton-type method. It can ensure the positive defmitiveness of the iterative coefficient matrix by using the L-M parameter, which avoids the ill-conditioning of iterative equations. The method, requiring only the approximate solution of a linear system at each iteration, is quite applicable to the large-scale cases.

在利用非线性互补函数将OPF模型的KKT条件转化为半光滑非线性代数方程组后，采用基于次微分的半光滑L-M法求解，该方法属于牛顿法范畴，可通过对L-M参数的调整保证迭代系数矩阵的正定性，克服了系数矩阵的奇异引起的"病态"，且该方法在确定搜索方向时只需求解线性系统的加热器近似解，适用于大规模系统的求解。

The relationships between the eigenvalues of Jacobi iteration matrix and the block AOR iteration matrix make a very important role in our analysis. Then we prove some sufficient conditions for the semiconvergence of the block AOR method.

利用块AOR迭代矩阵和相应的块Jacobi迭代矩阵的特征值之间所存在的关系，我们证明了求解奇异p-循环线性方程组的块AOR迭代法半收敛的一些充分件。

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。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。