查询词典 uniform approximation

Bonikowskis model, the covering upper approximation operation and covering lower approximation operation are not dual to each other. William Zhu proved them determining each other, but he cannot give the quantity relation of them.

Bonikowski定义的广义覆盖粗糙集模型中，上近似算子与下近似算子不满足对偶的性质，虽然William Zhu等证明了上、下近似算子是相互确定的，但是没有给出它们之间具体的数量关系。

In chapter 2, basic knowledge of the rough set theory, such as indiscernibilityrelation, elementary set, approximate space, upper approximation, lower approximation, negative region, boundary region, rough set, etc., and algebraic properties of rough set are introduced. At the same time, the feature of the rough, set theory is also introduced.

第二章介绍了粗糙集理论基本知识，如不可分辨关系、基本集、近似空间、上近似、下近似、负域、边界域、粗糙集等概念，以及粗糙集的代数性质，同时还介绍了粗糙集理论的特点。

In rough-set theoretic sense,the histogram correlates with the lower approximation and encrustation of histogram correlates with upper approximation.

从粗糙集理论意义上来说，直方图的外层与上近似有关，而直方图取值与下近似有关。

By virtue of a two-mode approximation and a rotating-wave approximation, an exact solution of the system is given.

利用双模近似和旋转波近似，得到了系统的精确解。

The finite difference approximation for this equation is presented.The stability and convergence of the finite difference approximation are analyzed.

并证明了显式格式条件稳定和条件收敛，而隐式格式则是无条件稳定和无条件收敛。

In order to solve the problem,starting from the analysis of the simplest plane wave numerical theory,we derived the formula of relative phase velocity and group velocity under the condition of arbitrary high-order finite-difference approximation,and gave the computational method for acquiring the optimum Courant number,and then analyzed the anisotropic effects due to finite difference approximation.

针对此，从最简单的平面波数值理论分析出发，推导了任意高阶有限差分近似条件下相对相速度和相对群速度的计算公式，给出了求解最佳Courant数的计算方法，分析了差分近似造成的各向异性效应。

College of Guandong Business, Guanzhou 510320, China）Abstract: Since large-scale vertical quench furnace is voluminous, whose working condition is a typically complex process with distributed parameter, nonlinear, multi-inputs/multi-outputs, close coupled variables, etc, dynamically decoupling control algorithm of temperature distributed parameter system in the furnace was presented, by which the whole system was decoupled to several subsystems and the implementation of controller was simplified. With finite difference approximation, the space and time step size was solved to ensure the convergency of finite difference approximation. After decoupling, the subsystems were controlled with self-learning PID control algorithm. The results show that the temperature control precision and homogeneity are improved; the overshoot and process in temperature rising period are reduced simultaneity.

摘 要：针对大型立式淬火炉体积庞大，工况复杂，炉内温度分布呈本征非均匀性，具有多输入/多输出、非线性、强耦合等特性，难以实现炉内温度高精度高均匀性控制目标等问题，提出一种温度分布参数系统动态解耦控制算法，其原理是：采用有限维逼近方法将对象解耦为多个独立的子系统，简化控制器的实现过程；通过分析有限维逼近方法的收敛性，获得保证收敛性的空间和时间步长应满足的条件；解耦后的子系统采用自学习PID控制算法，实现炉内温度高精度和高均匀性控制以及升温过程的快速性和小超调。

One position control system is introduced as the objective controlled by FOC. Based on Mittag-Leffler function, the fractional order control system with full memory length is adopted as evaluation criterion, and an approximation performance function of discretization methods is proposed. Analyzing the time domain error and approximation performance, the investigation to various discretization methods is carried out comparatively in detail.

引入一个位置控制系统作为分数阶控制对象，将Mittag-Leffler函数的全记忆长度分数阶控制系统作为评估基准，提出了一种离散算法的近似性能函数，通过时域误差分析以及近似性能分析，对比研究了分数阶微积分算子的数字实现方法。

The Paper mainly studies forecast of a kind of time sequence which is made by using fuzzy approximation and Functional differential Equation, gives several theorems which explicate fuzzy and optimal approximation and relation between them by using the forecasting method.

主要对以模糊逼近和泛函微分方程进行时间序列预测问题作进一步的理论研究，给出了几个有关使用该预测方法时，模糊逼近与最佳逼近及其关系的定理，证明了逼近方面及预测方面的一些有意义的结果。

Neural networks; Function approximation ; generalized Fourier series ; approximation capability

神经网络；函数逼近；广义Fourier级数；逼近能力

According to our present broadcasting situation,the thesis proposes using new technology to update and reform the present HFC. It also suggests broadcasting using self-advantage and arranging EPON in order to win the supermarket.

论文从我国广电的现状出发，结合实际，积极倡导采用新技术更新、改造我国现有的HFC网络；倡导广电现阶段利用自身优势，部署EPON网络来赢取市场。

A new general kinetic equation was derived in which the effect of the removal of condensation water was taken into account completely, and was applied to the polyesterification kinetic study of AA/HPHP and AA/NPG. It was found that the reaction order of self-catalyzed polyesterification was not constant. For these polyesterifications, the reaction order was 2.5 at a low temperature, while 3.0 at a high temperature.

考虑缩合水的排除对反应体系的影响，用体积浓度单位推导出一个新的聚酯反应总包动力学方程，并应用到AA/HPHP和AA/NPG两个聚酯化反应的动力学研究中，研究发现，自催化聚酯反应的反应级数并不是固定值，对于AA/HPHP和AA/NPG两个聚酯化反应而言，低温时反应级数为2.5，高温时反应级数为3.0。