查询词典 numerical algorithm

Researches on kernel clustering algorithms. After combining K-means clustering algorithm and the theory of kernel-based learning algorithms, we propose a fast kernel K-means clustering method which is based on CPD kernel. The experiment results indicate that the clustering effect of the algorithm is better than that of K-means algorithm, the clustering speed of the algorithm is also fast than that of K-means algorithm.

核聚类算法的研究：探讨了K-均值聚类算法，通过将核学习理论与K-均值聚类算法结合，提出了一种基于CPD核函数的快速核K-均值聚类算法，并将该算法与基于Mercer核的核聚类算法进行了比较，实验结果显示，我们的方法不仅比K-均值聚类算法的聚类效果好，而且聚类速度快。

The unique advantage of this halfanalytical numerical method is that the analytical process of Conformal Mapping can transform an irregular area into a regular one such as a rectangle. Therefore, the discretization error of numerical methods on the boundary can be avoided, and the numerical algorithm can be implemented more easily, with the computing efficiency improved.

这种保角变换的半解析数值方法的突出优点是：利用前期的保角变换解析处理将不规则的场域转化为规则的矩形域，从而避免了纯数值技术对复杂边界的离散化误差，降低了后期数值计算的算法复杂度，并提高了计算效率。

The proposed method has the merit that the numerical characteristics of stochastic temperature field response can be obtained by analyzing the random temperature field just in one time.3. Perturbed numerical algorithm of nonprobabilistic convex set theoretical models on the temperature fieldThe uncertain parameters of physical parameters and initial boundary conditions of heat conduction are described by the convex model. The perturbation formulas of the upper and lower bounds of temperature field response with unknown-but-bounded parameters are given via the combination of matrix perturbation theory and the convex set theory model.4. Numerical analysis for transient temperature field with interval parametersConsidering the uncertainties of the transient heat transfer, the physical parameters and initial boundary conditions are regarded as interval variables.

该方法具有只进行一次随机温度场分析便可以获得其响应的数字特征的优点。3、温度场的非概率凸集合理论模型的摄动数值解法将结构导热的物理参数、温度场的初始和边界条件等不确定性参数以凸模型加以描述，基于矩阵摄动理论和处理不确定问题的凸集合理论模型的结合，导出有界不确定参数瞬态温度场响应所在集合的上、下界摄动计算公式。4、具有区间参数的瞬态温度场数值分析考虑结构瞬态热传导问题的不确定性，将结构各物理参数和温度的初、边值条件均视为区间变量。

This thesis is divided into six parts. The first chapter is preface, the current status of research in the inverse problems for parabolic partial differential equations is reported; the second chapter is "regularization methods for numerical differentiation and their applications ", in this chapter we investigate many regularization methods from a viewpoint of regularization theory and algorithm, some applications in the inverse problems for parabolic partial differential equations are given; the third chapter is "spectral regularization methods". Based on Fourier analysis, within the framework of regularization theory, we apply the spectral methods to some ill-posed problems. Many numerical experiments are done in order to show the validity of the methods; the fourth chapter is devoted to wavelet dual least squares method and a revised wavelet method; in the fifth chapter,we combine finite difference method with method of lines and apply it to the backward heat conduction problem in time; in the sixth chapter "identification problems for unknown source ", the essence and the degree of two problems related to source identification are pointed out, at the same time, some numerical methods are reported.

本文分为六个部分，第一章前言简要分析了国内外抛物型偏微分方程反问题的研究现状；第二章数值微分的正则化及其应用从正则化理论和算法的角度出发，考察了许多正则化方法，还给出了数值微分在抛物型偏微分方程反问题的一些应用；第三章谱正则化方法是在Fourier分析的基础上，在一般正则化理论的框架下，给出了这种方法在各种不适定问题中的应用，数值实验表明谱方法是有效的；第四章研究了小波对偶最小二乘方法和改进的小波方法；第五章主要研究了有限差分方法结合线方法在时间反向热传导问题中的应用；第六章是未知源识别问题，主要指出了两类未知源问题的不适定程度和不适定本质，同时报告了一些数值方法。

Based on modern optimization theory and optimal control theory, this dissertation studies some questions as follows:1. The optimization model of parameter identification of three-dimensional geologic history numerical simulation, algorithm and its applicationGeologic history numerical simulation is a basic content of basin numerical simulation, and the porosity is the major parameter in the evolution and development process of oil-bearing basin. According to the sedimentation and burial mechanism, the physical and chemical principles of oil geology, the mudstone porositys non-linear parabolic partial differential equation has been established.

本文应用现代最优化及最优控制理论，对如下一些问题进行了研究： 1、三维地史数值模拟的参数辨识优化模型、算法及应用地史模拟是盆地数值模拟的一个基础性的研究内容，地层孔隙度是含油气盆地地史演化发育过程中的重要参数，根据地层沉积埋藏机理和石油地质的物理化学原理，通过引入数学物理方程概念，建立了泥岩三维孔隙度场方程，根据问题的特点，给出了方程的定解条件，对方程的动边界也给出了处理方法，并且证明了解的存在性与惟一性，在此基础上建立了以当今实测数据为拟合准则的三维地史数值模拟的参数辨识优化模型，这是一个含有二阶偏微分方程约束的泛函极值问题。

The classical cutting stock algorithm——column generation technology , and wrap up rectangle technology for abnormity are analyzed ; The development of AutoCAD with ObjectARX is studied and the generating method of cutting outline drawing and layout drawing were found out on the basis of analyses of the graph database structure of AutoCAD and the basic operation of it ; The process planning technology of plate material cutting orienting numerical control is studied a process planning method directly based on layout drawing is established ; The emulation technology in AutoCAD is studied and a kind of dynamic emulation method is put forward , which is realized by incrementally modifying graph entity ; The postposition of NC program of the integrated cutting system constructed on software plug-in is proposed , which can effectively solve the problem that it is difficult for a numerical control programming system to be common , which is caused by the difference of instruction format and control parameter between different type of numerical control machine .

分析了经典的矩形件优化排样算法——列生成法和针对异形件的矩形包络算法；研究了基于ObjectARX 的AutoCAD 开发技术，结合对AutoCAD 图形数据库结构及其基本操作的分析，给出了下料轮廓图和排样图的生成方法；研究了板材数控下料加工的工艺处理技术，建立了一种直接基于排样图进行的图形交互工艺规划方法；研究了在AutoCAD环境中的板材下料数控仿真技术，给出一种通过增量修改图形实体对象实现的动态仿真方法；提出以软插件技术构建集成下料系统的数控编程后置处理部分，能够有效解决因数控下料机床指令格式及控制参数不统一导致的自动编程软件系统不易实现通用性的问题。

Mathieu function is the base of field theory analysis in elliptical cylinder coordinate system. So, firstly, detail investigation has been given about the problem of numerical analysis of Matheiu functions, based on the predecessor's contribution, an improved faster algorithm of numerical analysis and confirmation algorithm of Matheiu functions has been presented.

Mathieu函数是椭圆柱坐标系统下场论分析的基础，因此本文首先对Mathieu函数的数值计算问题进行了详细研究，并在前人基础上完善并进一步改进了目前被认为较为可行的数值算法，并提出了验证算法。

Organization: Manufacturing Engineering Institute, Chongqing UniversityAbstract: Based on the influences of opposite clearance on computer numerical control machining, the CNC code precompensation method of the CNC machining opposite clearance is introduced, and the precompensation process of opposite clearance is also introduced. The vector operation rules are used to research the algorithm of precompensation, and the proposed algorithm has been applied in a special numerical control equipment.

摘 要：在分析反向间隙对计算机数控（computer numerical control，CNC）加工影响的基础上，提出一种数控加工反向间隙的数控代码预补偿法，给出了反向间隙预补偿流程，并采用向量运算规则进行了预补偿实现算法研究，所提算法已在某专用数控设备上得到应用。

Firstly, after the analysis on probability distribution of GenCos' bidding results, a concept of bid acceptance probability distribution function of GenCos is proposed; then based on the features of bidding structure in day-ahead and real-time markets, a multi-objective bi-level programming bidding strategy model in day-ahead and real-time markets for GenCos is built for electricity markets in which the step-wise bidding function and pay-as-bid settlement protocols are utilized; and then in order to solve the proposed model an algorithm based on Monte Carlo method and genetic algorithm is designed; finally, the simulation of numerical examples are performed to verify the correctness of the proposed model and algorithm.

首先在分析了发电商竞价结果的概率分布之后，提出了发电商竞价成功概率分布函数的概念。然后基于日前和实时市场中投标结构的特点，针对采用分段报价和按报价结算(pay as bid price，PAB)方式的电力市场，建立了日前和实时市场中发电商的多目标二层规划竞价策略模型，并设计了以蒙特卡罗方法和遗传算法为基础的求解算法。最后采用算例对所提出的模型和算法进行了仿真验证。

Numerical experiments show that the new algorithm is not only an all-purpose algorithm, but also a high-performance algorithm with better results than others.

数值实验表明，新算法不仅是一种通用的算法，而且与已有算法的计算结果相比，其解的精确度也最好。

Fostering the concept of multi-culture firmly and mastering the development of advanced culture correctly are conductive to resisting terrorism, separatism of nationalities and ultraism of religion, which is of great academic theoretical, immediate and profound historical si...

牢固树立多元文化的理念和正确把握先进文化的发展方向，有助于在世界范围内自觉地抵制恐怖主义，民族分裂主义和宗教极端主义。不仅具有重大的学术理论意义，而且也具有重大的现实意义和深远的历史意义。

But if anyone walks in the night, he stumbles, because the light is not in him.

11：10 若在黑夜行走，就必碰跌，因为那光不在他里面。