查询词典 fitting of a curve

As for the difficulty to determine the point of maximum slope of the transition curve and the bug of using little information of the system, a PID parameters tuning method is presented in this paper based on multinomial fitting of the models transition curve.

针对实际中常用的飞升曲线法难以确定最大斜率处和利用系统信息较少的不足，提出了一种基于曲线拟合的PID控制器参数整定方法。

RCBV values calculated using cSVD and oSVD were identical. Both values were equal to the whole areas under the concentration-time curve were divided by the arterial input function areas. Moreover, these rCBV approximated to the rCBV calculated by signal-time curve fitting. rCBF with cSVD and oSVD wouldn't be underestimated by delay effect and were good for relative quantity. The scatter plots of rMTT and Td were useful in stroke staging.

cSVD和oSVD所得组织脉冲反应曲线的面积相等，均等於完整的浓度时间曲线下面积除以动脉输入函数下全部面积；而且，此结果和讯号时间曲线拟合很接近。cSVD和oSVD不会因延迟效应低估rCBF，可以良好反应不同组织的血流量相对值。rMTT和Td散布图在不同疾病种类或处於不同疾病分期，显示不一样的分布。

We discussed the total design of WEDM CNC programming system based on the Object Oriented Programming idea, studied the fitting method of a plane curve, used an efficient and stable curve approximating method; studied the planar translations of graphs and arc copulations between curves; discussed the interface technology to popular CAD software; discussed letters and images automatic programming system, and brought out a simple and convenient

该软件以PC为开发平台，以Windows为操作系统，采用了图形交互的编程方式，界面友好，操作方便。

However, the absolute curve magnitude at skeletal maturity is more predictive of long-term curve behavior rather than curve progression of a defined magnitude over shorter periods of skeletal growth.

然而，骨骼成熟时的绝对曲度较骨骼成长期的短期曲度进展角度对侧突的长期特点更有预测意义。

In the four section, from the interpolationdimension of an algebraic curve and an algebraic surface,using theoryand method of algebraic geometry, we get some interpolation of analgebraic curve and an algebraic surface, and we prove the reasonableof the interpolation dimension of an algebraic curve and an algebraicsurface.

第四章我们从沿代数曲线曲面空间的插值维数出发，利用代数几何理论与方法，给出了代数曲线曲面上的基本插值结构，并证明了我们长期应用的其上的插值维数公式的合理性。

An implicit Curve reconstruction method is proposed which represents the curve with all algebraic tensor-product B-spline,and minimizes the tension ofthe B-spline and the approximate geometric distance between the curve and the point set.

提出一种以代数张量积样条曲线作为几何表示形式，基于近似几何误差和薄板能量极小化的隐式重构模型。

An exstensive research on the calculation formulas for the abutment cone slope on skewed bridges is conclucted.Calculation formulas of key parameters on slope curve are derived through analytic calculation of ellipse curve at slope bottom.The values of parameters are discussed and various forms of cone slope and curve at slope bottom are detailed.

以斜交桥梁桥台锥坡为锥坡的一般形式展开较深入的研究，通过对坡脚椭圆曲线的解析计算，推导得出坡脚曲线各控制参数的计算公式，并对其取值进行讨论，详细说明了锥坡和坡脚曲线的各种形式；进而推导了斜交锥坡的体积、护坡体积、表面积和基础体积的计算公式。

This algorithm firstly translates arbitrary parameter curves into the piecewise cubic-degree Bezier curves, then using the properties of Bezier curve we can get the tangent vector and the normal vector of every point on the approximation curve, and calculate the approximating offset curve.

此算法先将任意形式的参数曲线转化成分段三次Bézier曲线，利用Bézier曲线的性质容易得到逼近曲线的切向量和法向量，从而计算出其等距逼近曲线。

Experiments of flow conductivity closure stress of typical propping agent are done, propping agent short-term flow conductivity alteration index is defined, by this, the relation between fissure short-term flow conductivity and closure stress, it is close to exponential relation. 4. Establishing the mathematical simulator of hydraulic fractured well's production in a steady state, finding the relation curve between dimensionless flow conductivity and fracture penetration coefficient by means of calculation and analyses, it is the basis of hydraulic fracture. 5. Expatiating the importance of optimized hydraulic fracturing design in reservoir engineering, advancing the optimizing design method, fracture dimension can be calculated easily when the physical parameters are known. 6. Production rate decline standard curve of vertical fractured wells is achieved by mathematical simulation, when the flow pressure is certain , by asymptotic analyze, this decline curve is close to exponential relation.

完成了国内外典型支撑剂的导流能力闭合应力影响实验，在数据分析中定义了支撑剂短期导流能力变异系数，并由此发现裂缝短期导流能力随闭合应力变化的近似符合指数关系式； 4 建立了一种水力压裂井稳态产能的数学模拟器，计算分析找到了最优无量纲导流能力与裂缝穿透比之间的新型关系曲线，它是水力压裂优化设计的基础； 5 阐述了水力压裂油藏工程优化设计的重要性，提出了优化设计方法，在已知支撑剂物性参数条件下可简洁计算最优裂缝尺寸； 6 数学模拟给出了垂直裂缝井产量递减标准曲线，在井底定压条件下通过渐近分析表明，该递减曲线满足指数关系式。

In this paper,the author obtains some features of Bertrand curves such as that necessary and sufficient conditions for a Bertrand curve is curve,discusses the distance from a point of a Bertrand curve to the corresponding point of the mate of Γ,the angle of the two tangent lines and so on.

讨论了Bertrand曲线的特征，得出了诸如曲线是Bertrand曲线的充要条件，Bertrand曲线Γ上的点与其偶线上对应点的距离，以及两点切线交角等结论。

The dissecting of samples in group2 were difficult. The root of pulmonary artery and ascending aorta failed to be unfolded because fibrous tissue was tough, right and left fibrous trigone were too firm to be solved by hand. Cardiac muscle fibers couldn't be stripped along myofibrillar trajectory since they were prone to break because of their friability.

组2的心脏解剖困难，表现为纤维组织坚韧，游离肺动脉非常困难；徒手无法松解左、右纤维三角，肺动脉和主动脉根部的游离非常困难；心肌纤维坚硬、质脆，解剖时容易断离成碎块，无法沿纤维走行方向剥离。

We have battled against the odds in a province that has become increasingly violent.

我们对在一个争夺日益激烈省的可能性。