查询词典 iterative method

We analyze the advantage of the simple iterative method over Newton method at last. The numerical examples show that the more computational time has saved by the simple iterative method than the Newton method.

最后分析了简单迭代和牛顿迭代的优劣对比，数值算例表明在同样精度下简单迭代更节约计算时间。

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。

In this paper Ⅰ successfully applied these methods to fault diagnosis, and presenting some new innovative machinery fault diagnosis method; First Ⅰ present a new gear wornout fault diagnosis method, this method use the vibration signal's time-frequency attribute and instantaneous phase undulation to accurately detect gear's fault, and by comparing with the traditional frequency domain analysis method, this method reveals that many nonlinear and nonstationary characteristic exist in gear's vibration, this tell us that if we use frequency domain analysis method without pay attention to the signal's characteristic, we could get wrong diagnostic result; Then Ⅰ present a new bearing fault diagnosis method, this method use ATVFD and Hilbert transform to do envelop demodulation,Ⅰ analyze the envelop with time-frequency method and find out that this method is more accurate then traditional method.Ⅰ also explain that the modulation of the fault to the carrier wave may also be non-stationary and nonlinear; Finally Ⅰ present a cylinder pressure measurement method of diesel engine by means of vibration, cylinder pressure is an important parameter of diesel engine fault diagnosis, the pressure measuring is simplified a lot by this method,Ⅰ also use the ATVFD and time-frequency analysis to realize it.

本文中将上述理论方法成功地应用到故障诊断中去，提出了几点创新性的诊断方法；提出了一种齿轮磨损故障诊断的新方法，该方法利用振动信号能量的时频域分布特征与瞬时相位波动特征可以进行精确的齿轮故障诊断，并通过与传统的频域诊断方法的比较，揭示出齿轮振动中存在的明显的非线性与非平稳特征，说明了不加选择地利用频域分析方法进行齿轮故障诊断很可能会得到错误的诊断结果；提出了一种轴承故障诊断的新方法，该方法利用ATVFD分解与Hilbert变换进行包络解调，并对解调得到的包络信号进行时频域分析，可以实现更加准确轴承故障诊断，说明了故障对载波信号的调制往往也是非平稳与非线性的；提出了一种利用振动信号进行柴油机汽缸内压力检测的新方法，柴油机汽缸压力的变化是柴油机故障诊断的重要参数，利用振动方法可大大简化汽缸压力的检测过程，该方法也是综合利用ATVFD分解与时频域分析方法实现的。

A mixed iterative method for 3-D frictional contact problems is proposed based on a combination of the iterative method and the fixed point method.

利用迭代法与不动点算法相结合给出了三维摩擦接触问题的一种混合迭代算法，克服了三维问题在接触面上因有无穷多个可能的滑动状态而无法确定带来的困难。

Direct method of Gaussian elimination, Gaussian main-element elimination, and the iterative method of Jacobi iteration, Gauss - Seidel (Gauss - Seidel) iterative method is linear equations numerical solution of important ways.

直接法中的高斯消去法、高斯列主元消去法，以及迭代法中的雅可比迭代法、高斯-赛德尔（Gauss-Seidel）迭代法又是线性方程组数值求解的重要方法。

An incremental-iterative method based on the Newton-Raphson method combined with constant arc length of incremental displacement vector is employed for the solution of nonlinear equilibrium equations. The subspace iterative method is used for the solution of natural frequencies and vibration modes for the free vibration of beam structures.

本研究推导元素的节点惯性力时，先将元素扰动位移表示成当前固定元素座标的扰动位移和旋转之函数，故可直接求得元素的节点惯性力，元素的一致性质量矩阵可由元素节点的惯性力对元素节点的加速度微分求得。

This paper investigates alternating iterative method and generalized alternating method for the solution of a large linear system, extend the convergence theorem and comparison theorem for generalized or alternating iterative method when the coefficient are Hermitian positive definite systems.

本文主要研究了大型线性方程组的交替迭代法及迭代法的各种变形，给出了当系数矩阵为Hermitian正定矩阵时各类迭代法的收敛原理及其相应的比较理论。

when computing the next tracing point, the traditional tracing method generally used the iterative method. but the iterative method had to face the following problems.

摘 要：传统的跟踪方法在求下一个跟踪点时一般是采用迭代法，而迭代法会出现初始值的选取和迭代收敛的问题。

Based on the improved Atiken iterative method and dimidiate method, a new algorithm of searching zero of derivative function is given, the simulation results show that if using the new algorithm to find the zero of derivative function, the convergence speed is faster than the improved Atiken iterative method .

采用二分法预报、改进的Aitken迭代校正的方法，构造了一种求导数零点的一种新算法。新算法在迭代过程中不用计算导数，且二阶收敛。数值试验表明，该算法具有较高的精度和较大的初值选择范

From the view of initial deformation,the dual intercrossed iterative method is developed to determine the initial deformations of cables and hangers,sequential method based on initial deformations to simulate the tensioning process in batches,and converse iterative method in sequential anal.

本文从索初始变形的角度出发，针对该类结构的特点，提出了&双重交叉迭代法&确定拉索和吊杆初始变形，索初始变形&顺序分析法&模拟分批张拉施工过程以及索张拉力&顺序分析逆迭代法&解决张拉力已知时的预应力施工过程模拟问题，并将这三种方法进行不同组合，解决各种情况下的多次、分批张拉施工过程分析的问题，由此确立了一套完整的适合该类结构的预应力全过程分析方法。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。