查询词典 approximation

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。

In addition, we give the new form of emission area extraction functionΓ with HK approximation.

另外，我们还给出了面积获取函数Γ在HK近似下的新形式。

One bases on function value and another bases on arithmetic average difference quotient. In this paper, the author mainly studies the approximation properties of both the function value and the derivative of two kinds of splines interpolation mentioned before, and the optimal error constants are obtained finally.

文中分别就这两类插值样条的函数值及一阶导数的逼近性质展开讨论，相应得出这两种插值函数在被插函数分别为一阶连续可导和二阶连续可导情况下的最佳误差常数。

In design of floating-point division, we can use functional iteration arithmetic or very high radix division arithmetic. In the beginning, we use a look-up table to obtain an accurate initial reciprocal approximation, and reduce the time of delay.

在浮点除法器的设计中，若用函数迭代或高基数算法进行除法运算，计算开始时，通过浮点倒数查找表获得一个较精确的初始除数倒数近似值，可以减少除法的迭代次数，缩短运算的延迟。

Experimental synchronous rotor internal mixer and two kinds of 55L synchronous rotor internal mixer, consulted a number of published articles at home and abroad, then, for the first time, formed four kinds of physical model and the corresponding mathematical model which related to the mixed stock between the mixing chamber side and the top of the rotor wing, to the mixed stock between the two rotors and to the mixed stock at the various temperatures of the mixing chamber. And from the character of model, the author gave the relevant analytic solutions and finite element approximation arithmetic solutions during the experimental process of the synchronous rotor internal mixer.

因此，本文作者在XM—1.7实验用同步转子密炼机和两种50L同步转子密炼机上进行了大量的实验，并参阅国内外已发表的文献和资料，首次建立了同步转子密炼机混炼过程中，胶料在转子棱峰与密炼室壁之间、胶料在两同步转子之间和密炼室中混炼胶温度变化的四种物理模型及其相应的数学模型，并根据所建模型的特点，分别给出了相应的解析解或有限元数值解。

Transmitting and receiving impulse response of two-dimensional array are obtained by the summing impulse response of a single rectangular element with differentia delay time. The approximation arithmetic of array element impulse response is discussed.

讨论了单阵元声场脉冲响应函数的快速近似算法，通过对不同延时量的矩形单阵元声场脉冲响应函数进行叠加，得到了二维换能器阵列的发射和接收脉冲响应函数，再施加以宽带脉冲激励函数，从而得到二维换能器阵列的声场分布。

According to the approximation ability of WNN, the nonlinear system is able to be modeled, obvious effect was shown in process modeling of residuum cracking and prediction of asphaltum yield and pyrolysis gas yield.

利用小波网络的逼近性，对非线性系统进行建模和预测，通过渣油裂解的实例，将小波网络与RBF网络作为对比，可以看出，小波网络的建模和预测效果都优于RBF网络。

Though comparing Canny operator and center B spline dyadic wavelet, the following conclusion is proven in this dissertation: a Center B spline function has tight support and Canny operator hasn't. b Center B spline function asymptotic convergence to Gaussian function and the derivative of Center B spline function asymptotic convergence to Canny operator. c The derivative of fourth order center spline B function is more suitable as a optimal edge detector than Canny operator. d Center B spline function can balance the smoothing and approximation of original data, and the fourth center B spline function is the only optimal solution of two order smoothing problem. e The error between the valve of time-frequency uncertainty of the fourth center B spline function and the lower bound of time-frequency uncertainty does not exceed 0.143% of the lower bound. f The derivative of center spline B function can construct a stability dyadic wavelet and can give a fast algorithm for multiscale edge detection, but Canny operator can do neither.

作者给出了Canny算子与中心B样条二进小波严格的比较证明，得出如下结论：a中心B样条函数具有紧支集，Canny算子不具有紧支集。b中心B样条函数的极限收敛于高斯函数，中心B样条函数的导数收敛于Canny算子。c四阶中心B样条函数的导数比Canny算子更接近最佳边缘检测滤波器。d中心B样条函数比高斯函数更能兼顾对原函数平滑和逼近的折中要求，并且四阶中心B样条函数是二阶逼近问题的唯一最优解。e四阶中心B样条函数的时频测不准关系值与时频测不准关系下界的逼近误差不超过0.143％。f中心B样条函数的导数可以构成稳定的二进小波，存在快速的多尺度算法；而Canny算子不构成稳定的二进小波，无法给出快速的多尺度算法。

Firstly, the Voronovskaja type formula of asymptotic expansion of this kind of operators is given. Then the approximation of the bounded variation functions by the kinds of operators is discussed.

第一节给出该算子的Voronovskaja型渐近展开公式；第二节讨论该算子对有界变差函数的逼近。

The error analysis of asymptotic approximation of finite series expansion is also given. Our method avoids choosing the integral length of the reentrant comer, and can be used to calculate the charge on the conductor conveniently and efficiently. Numerical examples are presented to demonstrate the efficiency of the method.

本文算法克服了邓肯矫正需要选择角点积分区域的不足，有效地校正了导体角点奇异性引起的电容参数提取的计算误差，最后给出了算法的数值实验与分析结果。

Chimborazo and Cotopaxi, took me by the hand.

越过琴博腊索山和科托帕克西山。

This car is in a good condition.

这辆车的状况很好。