查询词典 cubic curve

This paper establishes cubic spline function, analyzes subsection curve function and curve slope and curvature, at last decides to place the curve especial points which can be obtain easement curve length and other line parameters, such as the ZH point (end of line and beginning of transition curve), the HY point (end of transition curve and beginning of circular curve), the QZ point, the YH point (end of circular curve and beginning of transition curve), the HZ point (end of transition curve and beginning of line).

针对公路平面线形的8种组合类型，其线形元素特征则由最基本的直线、圆曲线、缓和曲线组成的特点，解析三次样条函数模型，得分段曲线函数、曲线斜率、曲率，从而确定曲线特征点（直缓ZH点、缓圆HY点、曲中QZ点、圆缓YH点、缓直HZ点）位置，进而得到曲线缓和曲线长度及其他线形参数。

In this paper, a region approximation idea that means using a "fat curve" with a width to approximate the offset curve is proposed, and a complete set of algorithms to approximate offset curve using disk Bézier curve are given and implemented. In the algorithms, the optimal and uniform approximate curve of the offset curve as the central curve of the Disk Bézier curve is found by using Remez method, and then the upper optimal and uniform approximation principle is proposed to compute the error radius function of the Disk Bézier curve. Thus, the whole Disk Bézier curve can be obtained. In the end of this paper, the approximate effect of the Disk Bézier curve is not only analyzed and assessed, but also some specific examples are provided.

提出用一条带宽度的"胖曲线"来逼近上述等距曲线的区域逼近思想，并建立与实现了圆域Bézier曲线等距逼近的整套算法，包括应用Remez方法求出等距曲线的最佳一致逼近曲线作为圆域Bézier曲线的中心曲线，提出上控最佳一致逼近的原理求出圆域Bézier曲线的误差半径函数，以及确定整条圆域Bézier曲线，最后还对该圆域Bézier逼近的效果做了分析和考核，并给出了一些具体实例。

Then, have stressed kinds of technology cubic Hermite function and cubic spline function, step by step, expand dual-cubic Hermite and dual-cubic spline function to progressively, sum up in the point that trinary cubic Hermite and trinary cublic spline finally.

讨论时重点突出了三次埃尔米特函数和三次样条函数，表达方式由浅入深，逐步扩展到双三次埃尔米特函数和双三次样条函数，最后归结到三三次埃尔米特函数和三三次样条函数。

As an example to cubic trigonometric polynomial Bézier,the characters of trigonometric polynomial Bézier curve is analyzed,and deduced that cubic trigonometric polynomial Bézier curve is more smooth than cubic polynomial Bézier curve.

Bézier曲线是计算机辅助几何设计中的一类重要曲线，文献[1]介绍了三次Bézier曲线插值，文献[2]介绍了三次Bézier曲线的保凸插值，但难以解决一端曲率为0，另一端曲率比较大的插值问题。

The cubic algebraic curves (the Bezier curve and B style curve, etc belong to the parameter curve) is apter to realize the curve transition and fitting to dispersed data than the cubic parametric curves.

比如参数曲面与平面的交线就是一条平面代数曲线；平面参数曲线的等距曲线也是一条代数曲线。

Blue Nile originated in the Ethiopian highlands at an elevation of 1830 meters of Lake Tana, the plateau rainy and humid, water, a larger flow of 1640 cubic meters mouth of seconds, while the E White Nile is only 845 cubic meters seconds, half of the Blue Nile, and another Art E Bala river runoff flow of 392 cubic meters seconds, except for losses along the way, the average flow of the Nile mouth of E is only 2200 cubic meters second in the world, the Nile River in the amount of water E is the smallest.

青尼罗河发源于埃塞俄比亚高原上海拔1830米的塔纳湖，高原多雨湿润，水量较大，河口处流量为1640立方米秒，而E白尼罗河只有845立方米秒，是青尼罗河的一半，另有阿特E巴拉河来水流量392立方米秒，除去沿途损失，尼罗河口处E平均流量只有2200立方米秒，在世界大河中尼罗河的水量E是最小的。

Finally it analyzes the feasibility that using hydromechanics to analyze traffic flow by contrasting various characters between traffic flow and fluid flow. It analyzes influence of road alignment to basic expressway segment capacity by hydromechanics, and obtains viscous resistance and viscous movement differential equation when the vehicle drives on circular curve segment of expressway. And it infers that viscous resistance is correlated with sideway force coefficient, slope of crown and radius of circular curve. Radius of circular curve, sideway force coefficient and slope of crown are bigger, viscous resistance is smaller, the influence to capacity is smaller when the vehicle is running on nearside lane of circular curve; but radius of circular curve and sideway force coefficient are bigger, slope of crown is smaller, viscous resistance is smaller, the influence to capacity is smaller when the vehicle is running on fast lane of circular curve.

最后通过对比交通流与流体流的相似性，运用流体力学分析了道路线形对快速路基本路段通行能力的影响，求出了车辆在曲线路段的粘性阻力，建立了车辆在曲线路段的粘性运动微分方程，并由此推知，粘性阻力与横向力系数、路拱横坡度和圆曲线半径都有关系，当车辆在圆曲线外侧车道上行驶时，圆曲线半径、横向力系数和路拱横坡度越大，粘性阻力就越小，对道路的通行能力影响就越小；而当车辆在圆曲线内侧车道上行驶时，圆曲线半径和横向力系数越大，路拱横坡度越小，粘性阻力就越小，对道路的通行能力影响就越小。

Result: Scoliosis was identified in 58 cases with Marfan syndrome (38 males and 20 females), the prevalence rate was 42.03%, male-female sex ratio was 1.18:1, 6 cases were in younger than 10-year-old group. 12 cases were in 11~20-year-old group, 19 cases were in 21~30-year-old group, 11 cases were in 31~40-year-old group, 7 cases were in 41~50-year-old group, 3 cases were in 51~60-year-old group. Mean magnitude of Cobb angle in coronal plane was 26.8°±27.8°, the types of scoliosis curve included thoracic curve (36 cases), thoracolumbar curve (11 cases), lumbar curve (2 cases), double curve (6 cases) and triple curve (3 cases), apex vertebraes were convex to the right side among single curves in 38 cases while 11 cases were convex to the left side. Mean magnitude of kyphosis in sagittal plane was 14.3°±13.2°, 5 patients had thoracic lordosis and 40 patients had hypokyphosis and 12 patients had normal kyphosis.

结果：58例(42.03%)患者合并脊柱侧凸，男38例，女20例，男女患病率比例为1.18：1，其中≤10岁6例，11~20岁12例，21~30岁19例，31~40岁11例，41~50岁7例，51~60岁3例；平均冠状面Cobb角为26.8°±27.8°；胸弯36例，胸腰弯11例，腰弯2例，双弯6例，三弯3例；单弯中顶椎凸向右侧38例，凸向左侧11例；矢状面胸椎后凸平均为14.3°±13.2°，其中胸椎前凸5例，胸椎后凸不足40例，胸椎正常后凸12例，仅1例胸椎后凸45°；11例患者冠状面Cobb角＞40°，平均年龄15.9岁。

From a neutral gray balance curve, the curve Y, m, and the basic coincideut from neutral gray balance curve, the curve Y, m, and C coincideut basic curve the Y, m into a bow-shaped curve.

而从洋性灰不均弧线来看，Y、M弧线根基重分，而从洋性灰不均弧线来看，Y、M弧线根基重分，而C弧线则矮不入Y、M成为一条弓形弧线。

It's the first time that from the angle of computational mathematics combined with the structure model of parallel machine, the parallel degree of the relevant algorithms in orthopaedics clinic engineering modeling system, such as piecewise cubic Lagrange interpolation formula, piecewise cubic Hermite's interpolation formula, cubic spline, Chebyshev multinomial fitting algorithms, least square method and contour curve multinomial algorithms, were discussed.

论文首次从计算数学的角度并结合并行机的结构模式出发，讨论了在骨科临床工程造型系统中可能涉及的如分段三次拉格郎日插值公式、分段三次埃尔米特插值公式、三次样条函数、切比雪夫多项式拟合算法，最小二乘法以及轮廓曲线多项式求值算法的并行度。

Objective:To explore the feasibility of laparoscopy in diagnosing and treating of abdominal diseases.

目的：探讨腹腔镜用以诊断腹部外科疾病及选择治疗方案的可行性。

The lifetime of nylon 1010 and nylon 1010/POSS composites decreased with increasing temperature.

热重-红外联用分析表明尼龙1010在氮气气氛下的降解产物主要为小分子的低聚物，POSS并不改变尼龙1010降解产物的组成。