查询词典 approximation theory

After summarizing the existing research results, this article proposes new methods on moving force identification based on radial basis function approximation method and cubic spline function approximation method, and discusses the influence which some parameters to the precision of identification through calculating an example.

文章首先在第一章中介绍了已有的移动荷载识别方法及国内外的研究状况，在此基础上提出了研究目标和意义，即提出新的移动荷载识别方法，并通过数字模拟来讨论新方法的精度，以便评估桥梁的动力特性，为桥梁的设计和汽车性能的改进提供依据。

The properties of the λ-cut sets of the lower and upper approximation are discussed,and then the F-Union Decomposition theorem of the lower and upper approximation of rough fuzzy sets is given.

基于此，本文在逐一增加属性形式下的等价类F-分解的基础上，讨论了粗模糊集的F-分解形式，并给出了粗模糊上、下近似集合的F-分解定理及相关推论。

Thus, there is no way to demonstrate that sufficient data has been collected to form a mathematically valid approximation (or known degree of approximation) of the complete data set.

因此， 没有方法示范充份的数据已经被收集形成完全数据组的一个算术有效近似值。

Two-dimensional Bernstein type operators on simplex are constructed, and a necessary and sufficient condition of uniform approximation by mem is obtained, at the same time, the degree of approximation is characterized by two-order moduli of smoothness.

并且构造出单纯形上推广的二元Bernstein型算子，给出其一致收敛的一个充要条件，同时用二阶连续模刻划了它们的逼近度性质。

In this chapter we discussed the existence,uniqueness and approximation degree of binary cubic splines with C~2 connectivity for type-Ⅱtriangulations on rectangular domain,and we also gave a analysis of approximation of the interpolation splines.

本文还研究了二元三次样条函数在曲面重建中的应用问题，在TYPE-Ⅱ型剖分下，对于三次样条插值曲面的C~1-拼接问题，许多学者在这方面展开了大量的研究

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 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。

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。

He became prime minister in 1997 and won international acclaim for his role in the Northern Ireland peace process.

他在1997年成为总理，并且因为在北爱尔兰的和平进程中发挥的作用受到国际社会的赞许。

Mixed Page Sorting Method Using the cuttable user model, this thesis proposes a mixed page sorting method by using cutted user model in server-side and complete user model in client-side.

隐私分级利用的混合式页面排序方法针对个性化搜索中搜索结果排序的问题，本文利用隐私可控开放的用户偏好模型，提出一个在客户端和服务器端分步进行的隐私分级利用的混合式页面排序方法。