二次曲线

A typical 3-RPS parallel platform manipulator mechanism is firstly studied by means of the above theory. The principal screws of this mechanism under three different configurations are identified by means of the conic section and the quadric degenerating theory, respectively.

以上述理论为武器首先分析典型的3-RPS并联平台机构，分别应用二次曲线分解理论和二次曲面分解理论，识别了该机构在三种位形下的主螺旋。

Another new spatial 3-RPS parallel pyramid manipulator mechanism is studied. The principal screws of this mechanism under three different configurations are identified by means of the conic section and the quadric degenerating theory, respectively. The planar conics representing the relations between the pitches of the output twists and the three linear inputs are described, and the three-dimensional distribution of the axes of all the twists with the same pitch is illustrated under each of the configurations.

研究了另一种新的空间三自由度3-RPS并联角台机构，分别用二次曲线和二次曲面分解法识别该机构在三种位形下的主螺旋，绘制了其在每种位形下的输出运动螺旋的节距与输入之间的平面图以及具有相同节距的所有运动螺旋轴线在每种位形下的空间分布的立体图。

Automatic identification method of conics is studied based on the curve geometric invariants.

讨论了基于二次曲线不变量的圆锥曲线特征自动识别方法。

Inequalities in the proof of college entrance examination, often with the series, conics, trigonometric functions,"Three Second," the number of permutation and combination of combining the answers to questions.

高考中证明不等式问题，常常是与数列、二次曲线、三角函数、"三个二次"、排列组合数等相结合的解答题。

In order to recognize the 2D shapes, we proposed a set of perspective invariants of a pair of coplanar conics in this paper, we suggest a perspective invariant representation of general planar curve based on ellipse, and give an algorithm using the invariants and the representation to recognize 2D shapes.

为了实现二维形状的透视投影不变性识别，本文推导出了一种共面二次曲线对的透视投影不变量，提出了一种基于椭圆的平面曲线的透视不变性表示方法，并且给出了用该不变量和不变性表示方法实现二维形状识别的算法。

A manner is presented with which complex curves including polylines, conics or free curves can be precisely represented, and corresponding algorithm is designed. The curve can be C〓 or C〓 continuous. So all type of curves and their composites can be represented in NURBS. A deep research is paid to skinning surface. Different forms of the formation of knots vector are applied to different section forms.

对由多段直线、二次曲线、自由曲线进行任意组合的这类复杂曲线，提出了一种用一条NURBS曲线进行精确表示的方法，并设计了相应的算法，曲线段连接处根据需要可为一阶连续或形成尖点，从而使所有类型的曲线及由它们任意组合所生成的复杂曲线统一用NURBS表示。

The resulting curve breaks into two approximately straight lines. By purely empirical curve fitting method we obtain two straightline equations. Secondly, the recurrence interval and"rain-strength" relation curve on logarithmic paper will also br...

而在对数坐标轴内，频率和雨力的关系曲线，也分裂为二，分别用二次曲线和直线来配合，综合而成均方差很小的上海暴雨公式，以供市政规划设计的应用。

With the theory, any straight lines and quadratic curve′s equidistance curve can be indirectly interpolated with the help of outline and wire circle′s information, it is unnecessary to calculate equidistance curve .

该理论直接利用轮廓曲线和丝圆的信息，不需计算等距曲线，间接实现任意直线和二次曲线的等距曲线的插补，有效地避免了传统计算等距曲线产生的计算误差，简化了数控机床控制程序设计，提高了机床的控制精度。

Aimed at the characteristic of multiple types of faults possibly happened in nuclear power plant, large scale of training sample, and requirement of quick and accurate diagnosing, after the analysis of large sample number generated by large fault type exceeds limitation of 64K paragraph in DOS and large number of local minmum in error surface, measurements of same format of data file, Win95/NT operating system platform, resetting weight learning rate, dynamic training set in quick learning algorithm and improvement on quick learning algorithm using homotopy method which can avoid local minmum points in error surface have been adopted to ensure quickly and effective process of the course of neural network's training and testing.

针对核动力装置可能发生的故障种类多，训练样本规模大，故障诊断需要快速准确的特点等，分析了样本多和故障种类多产生的训练样本量超出DOS段大小和网络误差曲面上局部极小值多的情况，采取了使用相同格式数据文件、Win95/NT操作系统平台，对快速学习算法采用重置神经网络权值学习率和动态训练集、并采用能够有效克服网络误差曲面上局部极小点的同伦方法对学习算法进行改进等措施保证神经网络训练测试过程的快速、有效地进行；针对装置发生的故障须快速、准确诊断的需要，分析了故障的产生对装置参数变化的影响及操纵员对故障诊断的基础，在核动力装置发生故障时参数曲线的变化量与正常运行时参数曲线的变化量存在明显差异的基础上，提出采用参数曲线的变化量作为神经网络的输入，并围绕参数变化量的方法采用二次曲线拟合滤波求变化量和阈值技术来保证神经网络得到精确的装置参数变化量，从而得到准确的诊断结果。

Expression methods and growing rules accord with self-organization way are studied for binominal curves and surfaces such as arc, spiral, helicoid, ellipsoid and fractal curves such as snow-form curve.

研究了圆弧、螺旋线、螺旋面、椭球面等常规二次曲线/曲面以及雪花曲线等分形曲线的自组织表达和生长规则，实现并验证了其生长算法。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。