曲线拟合

In the paper, the math model of the fitting machining benchmark curve of stone slice has been given, which used on the handrail of eddied ladder , and circular helix has been used to bi a fitting curve, the general control machining linear slicer of stone, and has resolved the practical question on the machining of stone.

本文给出了旋转扶梯扶手石材贴片的加工基准曲线拟合的数学模型，以空间螺旋线作为拟合线，并给出用c语言编写的通用处理程序，为石材数控线切割机提供了理论基础，解决了石材加工行业中的实际问题。

By using the Graham scanning for the convex hull extraction and fitting these convex hull points with the conics,roots of the conics are regarded as points we need.

采用格雷厄姆扫描法对包络进行凸壳提取，并用二次曲线拟合凸壳点，计算出拟和曲线的根。

Unit 4: We introduce two methods of curve fitting, and then make use of them to extract body contour line, find the optimum fitting method.

第四部分：介绍了两种曲线拟合方法，接着利用它们分别对人体轮廓线进行提取，得出最佳的拟合方法。

Cubic spline function fitting is a good method in the curve fitting because it is characterized by very good subsection smoothness.

三次样条函数拟合是曲线拟合的一个公认的较好方法，它具有很好的分段光滑性。

At last, we gets the coefficients of rectifying curve ploynomial through the curves fitting of three order Hermite interpolation polynomial, second order interpolation polynomial, and presents a fitting methods of small current working.

本文对高压电动机测量用电流互感器在小电流工作时电流比值误差和角度误差进行了研究，通过对引起误差的各参数的深入分析，得到误差与电流的关系，并通过三次Hermite 多项式插值法、二次多项式插值法的曲线拟合，得到曲线多项式的各系数，提出一种小电流工作时的拟合方法。

Namely, the first, the beginning, end and length of growing season of every type of vegetation is estimated with threshold method and moving average method, and the beginning end and length of growing season of vegetation from 1982 to 1999 is fitted linearly, finally, linear trend of the beginning end and length of growing season of vegetation is analyzed. The second, phenological phase in different years and zones is estimated based on greatest changes of slope method and EOF analysis method, and the result monitored by the two methods is compared, as a result, trend of growing season change from 1982 to 1999 in different latitude zones is better acquired. The third, phenological phase of vegetation in different spatial location from 1982 to 1999 is fitted based on curve. Then, spatial difference rules of growing season of every year and average of multi-year is discussed in article. In the end, lag correlation and linear regress are used to study relation between phenological phase of different types of vegetation, different latitude zones, different spatial places and climate changes.

利用阈值法和滑动平均法逐年估测了每种植被类型的生长季的开始、结束日期及长度；对18年中植被生长季的开始、结束时间和长度进行一次线性拟合，分析了植被生长季的开始、结束日期和长度的线性变化趋势；基于最大变化斜率法和EOF分析法估计了不同年份、不同区域内植被生长季的开始、结束时间及其长度，并对这两种方法的监测结果作了比较，从而得到了较好的不同纬度区域1982～1999年植被生长季的变化趋势；基于曲线拟合了1982～1999年的不同空间位置的植被物候期，然后讨论了每年和多年平均的植被生长季的空间分异规律；最后利用时滞相关分析和线性回归研究了不同类型植被的物候期与气候变化的相互关系，不同纬度带的植被物候期与气候变化的相互关系，植被物候期与气候变化空间相互关系。

There are some mature curve fitting methods in the reverse engineering, such as Lagrange interpolation, piecewise polynomial interpolation, least square method and spline interpolation.

成熟的曲线拟合方法有拉格朗日插值法、分段多项式插值法、最小二乘法和样条曲线插值法等，本文在分析各自优缺点的基础上，提出选用三次样条曲线拟合法。

In curve fitting, the speed-flow rate curve shows that the curve of 16mm pitch wheel is a line and that of 12mm pitch wheel is a down-winding curve, the speed-pressure curves of two pitches both are up-winding curves and in the resistance-flow rate curves the curve of 12mm one has lower slope than that of the 16mm one.

曲线拟合结果显示，在转速-流量曲线中，16mm螺距叶轮为一直线，12mm螺距的叶轮为一向下弯曲的曲线；转速-压力曲线显示两者都是向上弯曲的曲线；阻力-流量曲线显示12mm螺距的叶轮斜率较小。

In this chapter, three kinds of target recognition methods are performed, which are:①Target recognition method based on the description of polarization parameter plane. The echo polarization states of target are projected onto the polarization state plane described by the ellipticity ε and the tilt angle τ of the polarization ellipse, the change of parameter following ferquency becomes the chart. According to the changing trait of the chart, the multidimensional polarization feature space of target has been contructed. Furthermore, a series of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.②Target recognition method based on the description of Poincare polarization sphere. The echo polarization states of target expressed by Stokes vector are projected onto the Poincare polarization sphere. The conception of polarization ferquency stability, which is used in describing the dynamic distribution characteristics of the target echo polarization states on Poincare polarization sphere, has been defined. A group of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.③Target recognition method based on the description of frequency sensitivity. In accordance with the conception of the polarization state distance defined on Poincare polarization sphere, the frequency sensibility of the physical structure property of target has been investigated, the frequency distribution feature curves in PSD domain are obtained, and targets'features are extracted by means of the curve-fitting method with Least Square Criterion.

这章具体研究了基于三种极化散射特性描述的相应的目标识别方法：①基于极化参数平面描述的目标识别方法，将目标回波极化状态投影到以极化椭圆参数，即椭圆率角ε和倾角τ表征的极化状态平面上，参数随观测频率的变化就形成了图，根据图的变化特点构造了目标的多维极化特征空间，并提取了不敏感目标姿态变化的极化特征参数组来设计目标的识别器结构；②基于Poincare极化球面描述的目标识别方法，采用Stokes矢量表征目标回波的极化状态，并将其投影到描述极化状态的Poincare极化球面上，定义了极化频率稳定度的概念用以刻画目标回波极化状态在Poincare极化球面上的动态分布信息，提取了准方位不变性的目标极化特征，最后设计了目标的识别器结构；③基于频率敏感性描述的目标识别方法，通过在Poincare极化球面上所定义的极化状态距离的概念，研究的是复杂目标物理结构特性对探测信号频率的敏感程度问题，获得了在极化状态距离下的频率分布特性曲线，采用最小二乘估计曲线拟合方法，它既用于极化特征的降维，同时又直接将拟合参数作为目标的分类特征。

Lsqcurvefit-Torque, least squares curve fitting, mainly for the engine work load curve fitting.

详细说明： Lsqcurvefit-Torque，最小二乘法曲线拟合，主要用于发动机负荷曲线的拟合工作。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐