查询词典 iterative

The best theoretical solution to a partitional clustering problem is to find all possible partitions and choose the partition that minimizes the objective function. However, the enumeration of all possible partitions is impractical even for data sets of moderate size. Therefore, as an alternative, most partitional approaches use an iterative optimization technique. And this could be cause local minimum.

本文在分析了目前聚类的基本方法的基础上，指出以K平均法等为代表的分割聚类虽然理论上找到类的所有划分并使得目标函数最小就可以获得最优解，但由于对于相当尺度的数据集列举所有可能的划分并不现实，因而多数分割方法采用迭代优化技术作为变通。

To assure astringency, sometechnologies have been used such as iterative penality function methods,assemblage mass matrix, reduced integration algoritlun, NeWton iteration methodwith parameters for non-linear equation set, introducing relax factors and doublesteps solution and so on, and an algorithIn for solving the nonlinear equation set offlow field by FEM has been presented.

基于有限元法建立了流场求解列式，为保证其收敛性，采用了迭代罚函数法，集中质量矩阵，缩减积分计算，带参数的Newton迭代求解，引入松驰因子及双层解法等技术，提出了一套适合流场有限元方程计算的非线性方程求解方法。

The non-structure grid is used for complex irregular boundary processing. An efficient algorithm PISO is used for the model and it can correct the bias of the mesh, so it can reduce iterative times. The flow pattern, energy dissipation ratio and velocity field are obtained.

根据不同的运行工况，利用计算流体力学软件FLUENT对无压隧洞洞内消能工的水流流态进行了二维简化数学模型的数值模拟，在求解过程中采用混合结构网格来处理复杂的边界形状；采用了效率较高PISO算法进行计算，在计算过程中进行了相邻校正和偏斜校正，减少了达到收敛所需的迭代次数。

An unsteady BEM is used to calculate unsteady hydrodynamic performance of the podded propeller. The interactions between the propeller and the pod are treated by two iterative calculation methods: induced velocity and induced velocity potential.

为了计算吊舱推进器的非定常水动力性能，建立了用诱导速度势处理吊舱和螺旋桨非定常相互干扰的方法，并和用诱导速度处理两者相互干扰的方法作了对比分析。

Polygenetic relationship among different types and resources of Narcissus was studied by RAPD and ISSR. And special marker in French type of Narcissus by RAPD was transferred to SCAR, which is more iterative and stable to identify this type materials.1. DNA concentration extracted from Narcissus by 2% CTAB little method was higher than that from other plants by this method or mass method. This indicated that tender leaf tissue with little cellulose was the direct cause of high deriving of Narcissus DNA.

本实验运用RAPD、ISSR对58份不同类型、不同来源的水仙材料进行亲缘关系研究，并将RAPD标记中法国水仙型的特异标记转化为重复性和稳定性好的SCAR标记，用于该类型材料的鉴定等研究工作中。

A frame image of a video frequency sequence is read into a postpositional memory zone, and staring position and size information of a tracked object is obtained in the frame, then distribution statistical information of a target signature is extracted to build a gauss mixed model as an object template, a mean vector and a covariance matrix in gauss mixed distribution are used to describe the position and the size of the object, then the next frame image of the video frequency sequence is read into the postpositional memory zone. In a new frame video frequency image, a parameter estimation method is used to obtain object gauss mized model parameters in the current frame in iterative computation and find candidate template similar to the object template, and the final model parameters obtained in iteration are used to update the tracking window for realizing self-adaption of the tracked window.

将视频序列的一帧图像读入缓存区，获得该帧中被跟踪目标的初始位置和尺寸信息，然后提取目标特征的分布统计信息建立高斯混合模型作为目标模板，用高斯混合分布的均值向量和协方差矩阵描述目标的位置和尺寸，再将视频序列下一帧图像读入缓存区，在新一帧视频图像中利用参数估计方法迭代计算当前帧中目标高斯混合模型参数找到与目标模板最相似的候选模板，利用迭代得到的最终模型参数更新跟踪窗口实现跟踪窗宽的自适应。

The preconditioned conjugated gradient method is a very efficient iterative method for solving large sparse linear equations.

预处理共轭梯度法是求解大型稀疏线性方程组的极为有效的迭代法。

After studying lots of preconditioned iterative methods (see[7]-[12]),on the one hand, in chapter 3,the preconditioner is considered to be applied

文中确定了参数的取值范围，在此范围内，AOR迭代以及2PPJ迭代的收敛性均得到了改善。

An interesting observation is that the classical iterative methods can all be viewed as instances of an preconditioned system with different preconditioners.

值得注意的是，经典的求解线性方程组的迭代法也都能够看作是求解采用不同的因子预处理之后得到的线性方程组的迭代法。

In this paper, we investigate the comparisons of asymptotic rates of iteration matrices of preconditioned and general iterative methods for solving non-singular linear systems.

本文讨论了解非奇异线性方程组的预条件方法与一般迭代法的比较理论。

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。