数的几何

It is pointed out that Ming Antu was the first inventor of Catalan numbers in the world . He constructed one geometric model, in which some infinite series with Catalan numbers as coefficients were contained.

指出了明安图是世界上第一位卡塔兰数的发明人，他构建了一个几何模型，在这个几何模型中包含了用卡塔兰数作为系数的无穷级数。

A number that typifies a set of numbers, such as a geometric mean or an arithmetic mean.

中数：代表一组数的一个数，如几何中数或算术中数

Two amelioration operators were developed, such as the triangular intuitionistic fuzzy numbers weighted arithmetic average operator, and the f interval-valued intuitionistic fuzzy numbers weighted geometric average operator.

定义了三角和区间直觉模糊集的一些运算法则，给出了直觉模糊集两个改进算子，即三角模糊数加权算术平均算子和区间直觉模糊数加权几何平均算子。

The geometric meaning of derivative.

导数的几何意义。

The definition, operation, properties, geometric meaning of quaternion and its three expressions are discussed. It is also demonstrated how to use quaternion to transform points.

本文详细叙述了四元数的这一功能，讨论了四元数的定义、运算、性质、几何意义和它的3种表达形式，给出了使用四元数处理点的各种几何变换的一般结论。

The reason why quaternion is used in flight simulation of fighter aircraft and the geometric meaning of quaternion are described,according to axis system used in flight simulation of fighter aircraft in China,three problems are introduced as follows:(1) quaternion kinematic equations,(2) relationship of quaternion and coordinate transformation matrix,(3) Euler angles in terms of quaternion.

阐述了在战斗机的飞行仿真中采用四元数的原因和四元数的几何意义，并按照中国战斗机飞行仿真中采用的坐标系，介绍了三个问题：四元数运动学方程；四元数与坐标变换矩阵的关系；用四元数表示的欧拉角。

Because of the condition of 〓 for two neighbour parametricspline surfaces is too strong,here,instead of it,some simple and practicableconditions of 〓 resulted from the general theorem obtained by Prof.LiuDing Yuan in Chapter 1 were proved,and three 〓 triangular splinesurfaces schemes wre presented:one is piecewise cubic spline surface patcheshaving local 〓 and whole 〓 continuity based on the refined HCTtriangulation,another is the same degree spline surface patches but based onthe refined Powell-Sabin triangulation,the third is piecewise quartic splinesurface patches having local 〓 and whole 〓 continuity based on therefined P-S triangulation.

由于对参数曲面，一阶导数连续的要求较强，我们采用第一章从刘鼎元定理导出的简单实用的几何连续条件，讨论了基于HCT加细三角剖分和P-S加细三角剖分上的两种局部达一阶导数连续而整体有一阶几何连续的分片三次样条曲面构造算法，一种局部达二阶导数连续整体有一阶几何连续的分片四次样条曲面构造方法。

In the last part of this dissertation, we discuss how to model an image is discussed and how to segment an image by EDEK.Zero-Cross principle is a classical concept in signal processing. We generalize the concept to be zero normal curvature after the geometry frame built. Furthermore, we present the explanation to choose the dual parameters in SPMVIF. And we research why the Laplacian gradient superior to edge gradient.

梯度方向二阶导数过零原理是信号处理中的经典结论，在运用微分几何的知识建立SPMVIF的几何框架的同时，将这个结论推广到零-法曲率的形式；另外我们对SPMVIF的双参数选取规则进行了讨论并给出它们的几何意义，并且对SPMVIF中法向矢量选取时拉普拉斯梯度优于边缘图像梯度的结论给予统计信息熵的解释。

And by applying the linear dispersion relation of wave, all the properties of wave refraction including wave rays, constant phase lines, phase function and crest lines etc., can be expressed in explicit functions. By introducing an orthogonal curvilinear coordinate along the wave ray and the constant phase line, and with an estimated scale factor, the refraction coefficients along any wave ray can then be determined. The present results are verified by ordinary wave ray theory and some previous numerical results.

就此特例情况在波浪的线性分散关係的应用下，前进波浪折射现象的整体特性，包括波向线、等位相线、位相函数与波峰线皆被导述出明確显然的函数表示；同时引入由沿著波向线与等位相线所构成的完全符合波浪折射几何通性的正交曲线座標，求出其尺度因子后，由能通量守衡原则定出沿著任一条波向线上的折射係数；並由之对往昔纯依两相邻的波向线间的几何类比所给定的折射係数给予导証之。

The line pencil equation for geometric elements in En is studied. From the direction number in the equation, the relative position between the elements and the projective space anp that between any two elements are analyzed.

本文系统地研究了E~n中几何元素的线束方程，由方程中的方向数分析几何元素对投影空间的相对位置和几何元素间的相对位置，规律性强。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。