查询词典 backward curvature

In this paper, we introduce the estimation and algorithm o f p arameter and some diagnostic statistics. We deduce the computation formula of curvature and conformal normal curvature for four perturbations of models.

本文主要介绍了指数族非线性模型的参数估计及其算法，若干诊断统计量，并将保形法曲率应用到指数族非线性模型中，推导了模型四种扰动方式的曲率和保形法曲率计算公式。

In 1986, R.D.Cook proposed differential geometry to assess local influence of minor perturbations of linear statistical models. Poon and Poon(1999) constructed a conformably invariant curvature , the conformal normal curvature, for the same purpose.

Cook(1986)用微分几何的方法评估了线性统计模型微小扰动的局部影响，Poon and Poon(1999)改进了Cook提出的统计曲率概念，定义了保形法曲率。

The interpolate algorithms of three-order NURBS curve and double three-orders NURBS surface are presented. The expressions of partial derivative and normal curvature of NURBS surface are derived by the theory of differential geometry. The geometric characteristics of different curvature area of the free-form surfaces are analyzed in detail. All these work lays a theoretical foundation for constructing the cutter location calculating model of free-form surfaces NC machining. 2 On the basis of analyzing the methods of cutter path generation, the standard of evaluating the various methods of cutter path generation is presented. The method of generating cutter path with constant scallop height is presented for the first time.

本文以提高复杂曲面多坐标数控加工精度和加工效率为目的，在对国内外研究现状进行深入分析的基础上，对数控编程中各环节的关键技术问题进行了深入研究，主要内容包括以下几方面： 1 分析了复杂曲面各种造型方法的优缺点，给出了根据各种边界条件所确定自由曲面的NURBS表示方法以及三次NURBS曲线曲面反算算法；用微分几何理论推导了NURBS曲面的偏导矢及法曲率计算表达式；对曲面不同曲率特性区域的几何特征进行了深入分析，为建立复杂曲面的数控加工刀位计算模型奠定了理论基础。

The first and second derivatives of the coordinates of a cam profile are calculated using numerical differentiation method,and substituted with curvature radius formulas in calculus,thus obtaining its curvature radius.

应用数值微分法计算凸轮廓线坐标的一、二阶导数，代入微积分学中曲率半径公式，即得凸轮廓线的曲率半径。

One is based on the B-spline fitting to the contours;the other computes the curvature directly taking advantage of the relation of curvature and osculating circle.

一是基于轮廓的B样条拟合，通过计算拟合B样条曲线在各采样点处的曲率估算轮廓点的曲率

For getting the major characteristic edges without confusions by undesired structures like muscle edges, we integrate a star-like edge detection filter named "Asterisk Filter" with the Canny Edge Detection in the image preprocessing. In addition, we also propose a new contour tracking method named "One-Pixel Rolling Ball Contour Tracking" for getting the boundary information in a binary image which is a link-list data structure. Instead of using a regression curvature estimator, PCA is used for better curvature estimation from a discrete bony contour.

为了从影像上取得骨头特徵边缘，将不重要的肌肉视为杂讯滤除，我们引用一种星形滤波器－Asterisk Filter，搭配Canny边缘检测法，做为这类影像的前处理；另外，为了将骨头的边缘精确地追踪出来，我们提出滚球边界追踪法，来对二值化影像进行边缘追踪，藉此获得边缘的串列资料结构；我们采用以主成分分析(Principle Component Analysis，简称PCA)取代原本以回归方法来计算的曲率，以取得更佳的曲率估测值，其可提高计算之参数的准确性。

At the every relative momentary point of time time-space, is to the situation of observe identity mutuality gravitation and space-energy quantum spatial measurement cosmic energy at relatively determine, namely to the difference of quantity quantum of the original spatial measurement and the spatial measurement limit of cosmic energy, to the quantity of quantum spatial measurement cosmic energy, to the situation of spatial measurement and spatial curvature relative time-space cosmic energy, to the difference of spatial measurement of the gravitation exceed the space-energy of quantum spatial measurement cosmic energy, to the situation of the average density spatial energy and the temperature spatial background of relative time-space cosmic energy, to the situation of spatial measurement and spatial curvature relative vacuum cosmic energy all at relatively determine.

在时空时间的每一个相对时刻点，是对宇宙能量的宇称量子的引力与空间能的守恒状况的相对确定。即是对宇宙能量的原初宇称量子与极限宇称量子的数量差，宇宙能量的宇称量子数量，宇宙能量的相对时空的宇称及空间的曲率状况，宇宙能量的宇称量子的引力大于空间能的宇称差，宇宙能量的相对时空空间的能量平均密度及空间的背景温度状况，以及对宇宙能量的相对真空的宇称及空间的曲率状况全都在相对地确定。

In reparametrization with arcs length, the curvature and torsion is invariant to translation and rotation transformation. The curvature and torsion are views as feature sets.

无论是二维碎片物体还是三维碎片物体的形状复原问题，皆看成是特殊的物体识别问题，其特殊性就是在处理的方法上采用基于轮廓线的匹配来识别。

We get some results about the scalar curvature of 2 and n(n≥3)dimensions Einstein manifold :ρ Maybe is constant and ρ is constant, the relation between Einstein Manifold and Riemannian Manifold with constant sectional curvature.

本文对其有关性质进行了讨论，得到了2维和n(n≥3)维爱因斯坦流形的数曲率的一些结果：ρ可能为常数和ρ为常数，以及爱因斯坦流形与常曲率黎曼流形之间的关系

Using the mathematical tool"DifferenceGeometry",it is possible to define the discrete geometric metrics such as discretefirst fundamental form,discrete second fundamental form,discrete unit mainnormal vector,discrete Gauss curvature,discrete mean curvature and discreteLaplacian.

首先，运用"差分几何"这一工具，可以构造离散第一、第二基本形式，离散单位主法向，离散高斯曲率，离散中曲率等离散几何量和离散Laplace算子。

The shaping method of noncircular part and the tool holder's radial motion characters in noncircular turning process are discussed in detail in the thesis.

论文详细研究了非圆零件的成型方法和加工过程中刀架的径向运动规律。

I have not really liked him,I do not like his this kind of disposition.

我没有真的喜欢他，我不喜欢他的这种性格。