二次曲线

Any shape of mining face ; integral region ; quadratic curve

非规则采矿工作面；积分区间；二次曲线

The characteristic points of the detected lane marking are transformed into the bird's view of the specific height via the Inverse Perspective Mapping. A second–order polynomial is used for curve fitting to obtain the lane model.

将所侦测到之道路标线特徵点，透过逆透视转换的过程，转换成从特定的高度观察之俯视景观，再利用二次曲线拟合方式，建构出车道模型。

Based on the Second Desargues Theory and involution theory,a simple drawing method for a conic is presented.

为了使二次曲线的作图更简便，文章以第二笛沙格定理和对合定理为基础，提出了一种新的作图方法。

So,the genetic distance could be used for the choice ofparents and for the heterosis prediction in cross breeding of Liriodendron.

因此，花粉品质、杂交亲和力和一般配合力应作为亲本选配的重要依据；基于RAPD标记的亲本间遗传距离与子代1年生苗高和地径生长量均表现为二次曲线相关，复相关系数分别为0.8235和0.5090，达极显著(H，P＜0.01)和显著(GLD，P＜0.05)程度，说明利用亲本间遗传距离进行鹅掌楸亲本选配和杂种优势预测是可行的。

Their seasonal variations were related with vegetation characteristics such as leaf area index and canopy height as well as wind speed.d had a close linear relationship with h,and the variations of Z0 with h could be expressed by quadric curves.d/h and Z0/h were nearly correlated with LAI,and multiple correlation coefficient could be 0.99 and 0.78,respectively.

芦苇湿地的Z0和d的季节变化主要受叶面积指数、株高及风速的影响。d随h的增加而单调增加，Z0随着h的变化遵循二次曲线，d/h、Z0/h与LAI之间的复相关系数分别为0.99和0.78。

QIQD uses piecewise quadratic curves to calculate the multiplicator of contending window after a frame collision and the divisor of contending window after a successful transmission, respectively, which is capable of reducing collision probability and improving channel utilization.

QIQD通过分段二次曲线计算数据帧碰撞冲突后增大竞争窗口的倍乘因子和数据帧成功传输后减小竞争窗口的倍除因子，从而能够降低碰撞概率和提高信道利用率。

The Beta and quadratic functions were used to describe daily thermal and photoperiod effectiveness, respectively.

分别选用非线性的Beta函数和二次曲线函数来定量描述每日热效应和光周期效应。

The method comprises the following: a step of calibrating a camera, which is to utilize a Taylor series model to calibrate an omni-directional vision sensor so as to obtain internal parameters of the camera; a step of obtaining epipolar geometric relation, which comprises the steps of calculating an essential matrix between binocular omni-directional cameras and extracting the rotation and translation component of the cameras; a step of correcting an outer polar line, which is to correct the outer polar line of a shot omni-directional stereo image so as to allow a corrected polar quadratic curve to coincide with an image scan line; and a step of three-dimensional reconstruction, which is to carry out feature point matching to the corrected stereo image and calculate the three-dimensional coordinates of points according to matching results.

该方法的步骤包括：相机标定：利用泰勒级数模型对全向视觉传感器进行标定，得到相机内参；对极几何关系求取：包括计算双目全向相机之间的本质矩阵，并从中提取相机的旋转和平移分量；外极线校正：对所拍摄的全向立体图像对进行外极线校正，使校正后的极二次曲线与图像扫描线重合；三维重建：对校正后的立体图像对进行特征点匹配，根据匹配结果计算点的三维坐标。

By using of principal component analysis,second curve forecasting method,expert fuzzy prediction method and other methods quantitative study of Yancheng Coastal Zone environmental indicators and subsystem level weights were done from 2006 to 2015,at the same time early warning and forecast of the impact on the environment of Yancheng Coastal Zone were established.

利用主成分分析法、二次曲线预测法、专家模糊预测法等方法，定量化研究了盐城海岸带环境指标及子系统和指标层的权重，并对2006~2015年的盐城海岸带环境压力进行了预警预测。

The new method gives out a set of equations based on the fundamental algebra rules that principal stress trace obeys and the essential attributes it possess, we then combine these equations with further information described in this paper leading to an exact description of the conic representing the principal stress traces.

该方法是根据主应力迹线满足过任意三条等倾线的主应力都可以用二次曲线来描述这一条件，再利用主应力迹线本身所具有的性质列出方程组解算出描述主应力迹线的一元二次方程，然后根据方程描绘出所求的主应力迹线。

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