查询词典 first-order derivative

In this paper, a new edge detection method——method using extremum of first directional derivative is proposed, based upon a general gradient edge model.

文中通过傅里叶变换，在频率域，通过求垂直于边缘的一阶方向导数，并检测其极值点来确定边缘。

Edge detection ; first directional derivative ; extremum ; Fourier transform

边缘检测；一阶方向导数；极值；傅里叶变换

Edge lines are extracted automatically from image, by acquiring points of extremum of first directional derivative vertical with edge line with Fourier transform in frequency domain.

同时，参考一阶方向导数的数值来排除一些非边缘点（一阶方向导数的数值为常数者，零也为常数）。

The match models were recalculated after the first derivative. Better results are achieved and the discriminability is remarkably enhanced, especially to the minimums distance model.

标 签 高光谱遥感地物光谱最小距离光谱角度匹配光谱相似度匹配导数 hyperspectral remote sensing spectral match model minimums distance SAM SCF derivative

In this paper, a new approach for automatic extracting the local maximum lines from the first horizontal derivative images of geophysical fields is proposed.

提出了一种自动提取地球物理位场水平一阶导数图象中局部极大值线的有效方法。

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。

The first rank derivative is a reflection of curve change and its rate, at certain range, if the sign of the first rank derivative has changed, the logging value of the correspondence depth point means maximum in this range; the second rank derivative is the knaggy property reflection of curve, at certain range, if the sign of the second rank derivative has changed, the correspondence depth point represent the inflexion of geophysical logging curve, it＇s also a turning point of the reflection of knaggy change property of the curve, it is the interface of stratum.

测井曲线的值是深度的函数，测井曲线的一阶导数表示了曲线变化的趋势和变化的快慢，在某一范围内，当一阶导数呈现符号转换时，相对应的深度点的测井值即为该范围内极大值；测井曲线的二阶导数则表示曲线的凹凸性，在某一范围内，当二阶导数呈现符号转换时，相对应的深度点代表了测井曲线的拐点，即反映曲线凹凸性变化的转折点，亦即地层的分界面。

In model experiments, we find that the deviation of the first derivative calculated by Fourier transform is very large to comparing with the theoretical derivative, but the fitting effect of the derivative of anomalies calculated by cosine transform is very good. The calculation accuracy of data are all very high except that errors of several data on the boundary are large because of the residual Gibbus effect induced by finite truncation of gravity anomalies. Errors are -009%～5%.

模型实验中发现，用Fourier变换计算的一阶导数与理论导数偏差很大，而余弦变换计算的导数与理论异常导数拟合效果非常好，除边界几个数据因重力异常的有限截断产生的吉布斯效应残留使误差较大外，数据的计算精度均很高，误差为-009%～5%。

His prospective father-in-law, however, reneged, perhaps making this not only the first derivative but the first default on a derivative.

他未来的岳父，但食言，也许这不仅使一阶导数，但第一次违约的衍生产品。

In addition, the approach is able to avoid the requirement of the upper bound of the first time derivative of the control gain, which is assumed to be known a priori in some of the existing adaptive fuzzy/neural network control schemes.

该方案能够避免现有的一些自适应模糊/神经网络控制器设计中对控制增益一阶导数上界的要求。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。