查询词典 second derivative

Combining the definition of CWT and the derivative property of convolution, we constructed a general method to calculate the approximate derivative of signal through CWT by using the first and second derivative of Gaussian function, Haar, and the first derivative of three-order-Spline function as wavelets. As compared with the other approaches of calculating derivative, which include the numerical differentiation, polynomial filters, Fourier transform, and the recently proposed DWT method, fast calculation and simple mathematical operation were remarkable advantages of CWT method. For the signal corrupted by severe noise (Signal-toNoise Ratio=5), the satisfactory results could also obtained via CWT method through appropriately adiusting the dilations.

在此基础上，(1)结合连续小波变换的特点和卷积的微分性质，提出了使用Gaussian函数的一阶和二阶导数，Haar和三次样条函数的一阶导数作为小波函数的连续小波变换计算信号近似导数的一般性方法，与其他导数计算方法(包括数字微分法，多项式滤波法，Fourier变换法和离散小波变换法)相比，本法简单便捷，计算速度快，对于噪声含量较高的信号(S/N为5)，只要适当调节尺度即可获得比较满意的结果。

Based on the simulated data produced by PROSAIL model and field test data, the authors respectively analyzed many kinds of factors which affect some representative inversion method s, such as VI, second derivative, model inversion and the directional second derivative.

以PROSAIL模型模拟数据和地面实测数据为基础，分别分析了土壤背景、冠层反射率非各向同性以及随机噪声等因素对几类代表性反演方法的影响(植被指数法、二阶微分法、模型反演法以及方向性二阶微分法)。

The formula requires not only the function value,but also the first derivative and second derivative value on node.

此类求积公式不但需要结点上的函数值，还需要结点上的一阶和二阶导数值。

By means of the Hermite interpolation formula with second derivative,a type of integrating formulas with second derivative is derived.

利用带二阶导数的Hermite插值公式，导出一类具有二阶导数的求积公式。

The results showed that there were three minimum values in the second derivative spectrums of normal person, in contrast there were four minimum values in most diabetic second derivative spectrums, the diabetic urine had one minimum value more than normal urine during the range from 550 nm to 570 nm.

发现健康人的二阶导数光谱都有三个极小值，与之形成对比的是绝大多数糖尿病患者的二阶导数光谱却有四个极小值，糖尿病患者的尿样在550 nm～570 nm区间范围内比健康人多出一个极小值。

And the spectrum was divided into three regions, which were 430~100 nm, 1 000~1 800 nm, 430~1 800 nm, respectively. Four methods of spectrum data preprocessing were used, which were multiplicative scattering correction, standard normal variate, first derivative and second derivative.

应用多元散射校正，标准正态变量变换，一阶微分和二阶微分四种不同预处理方法，分别在430~1 000 nm、1 000~1 800 nm和430~1 800 nm三个光谱范围内建立识别脐橙污染程度的偏最小二乘法数学模型。

Newton's second law also has second derivative of time...

这也是把量子力学意义下面的K－G方程作为基本动力学方程的一个问题吧。

The second derivative of f with respect to x; the derivative of f '.

f对x的二阶导数；亦为f'的导数。

By analyzing, an adaptive mode of linear filter based on DCT is given out. The curves of the vertical second derivative of gravity anomaly are matched well with those of the academic second derivative, and the calculating precision is much higher.

通过分析给出了基于DCT的合适的线性滤波方式，滤波后的重力异常垂向二阶导数与理论二阶导数拟合效果好，具有较高的计算精度。

To reduce or remove size effect, the size classification elimination method, volume average method and normalization method based on volume were presented and the calibration and prediction results indicate that these three methods could reduce or remove the size effect effectively. The normalization method is more suit to in-line application and obtained better calibration and prediction results with the r of 0.789, 0.858 and 0.947, the RMSEC of 0.596, 0.499 and 0.313, and the RMSEP of 0.606, 0.686 and 0.413 than the results without normalization with the r of 0.716, 0.793 and 0.848, the RMSEC of 0.678, 0.592 and 0.515 and the RMSEP of 0.825, 0.764 and 0.714 for the original spectra, the first derivative spectra and the second derivative spectra with soluble solids content using partial least square method , respectively. 4. Owing to much thick skin of watermelon, contrast experiment was conducted in skin-peeled watermelon and intact watermelon to compare the influence of skin on spectra.

针对西瓜果型大且差异显著的特点，研究果型差异对可见／近红外光谱以及建模与预测结果的影响，并提出三种方法消除或减小这一影响因素，分别是分级消除法、体积平均法和基于体积的正则化方法，其中基于体积的正则化方法，更适合在线生产应用，该方法使果型大小差异明显样品的原始光谱、一阶微分光谱、二阶微分光谱在对可溶性固形物含量检测时，采用偏最小二乘法的建模与预测结果由原来的校正相关系数r分别为0.716、0.793、0.848提高到r分别为0.789、0.858、0.947，均方根校正标准偏差RMSEC由原来的0.678、0.592、0.515分别降为0.596、0.499、0.313，均方根预测标准偏差RMSEP由原来的0.825、0.764、0.714分别降为0.606、0.686、0.413； 4。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。