反线性变换

In this paper, taking the downward continuation of potential field as an inverse problem of upward continuation, we obtain a convolution type linear integral equation for downward continuation. Making use of the orthogonal symmetry characteristic of Fourier transform matrix, and combining the principles of singular value decomposition of matrix and generalized inverse, we proposed a stable generalized inverse method for downward continuation of potential field, called wavenumber domain generalized inverse algorithm, which doesn't need the computation for inverse matrix. It resolves the instability of potential field downward continuation of large depth.

本文通过把位场向下延拓视为向上延拓的反问题，得到向下延拓的褶积型线性积分方程，再利用Fourier变换矩阵的正交对称特性，并结合矩阵的奇异值分解和广义逆原理，提出了一种稳定的不需要进行求逆运算的位场向下延拓广义逆方法——波数域广义逆算法，解决了位场大深度向下延拓的不稳定性问题。

Since the B-spline is a locally supported function, the smoothing formula can be strictly limited in a neighborhood of each point. The smoothing surface defined by the smoothing formula has the same convexity as that of the original image. Secondly, the edge points are detected by either computing the local extremum points of the directional derivative or computing zero-crossing of the second-order directional derivative of the smoothing surface. Finally, an example of an edge detector is given.

针对反卷积视觉模型的病态性，增加了适当的约束，给出了基于低松弛迭代格式的快速自适应滤波算法，对于一个N×N输入图象，由于变换核的局部支撑性质以及低松弛迭代格式的引入，使得快速自适应滤波算法的计算复杂度降为象素个数N〓的线性量阶N〓，就最小二乘算法的复杂性而言，优于不动点迭代算法的O以及基于FFT的预处理共轭梯度算法的O。

Plentiful and substantial achievements have been made, which motivate a lot of methods to obtain the exact solutions of solitary wave equations, such as: the homogeneous balance method, the hyperbolic function method, the power series method, besides the traditional methods, such as: the inverse scatting method, the bilinear Hirota method, and the Backlund transformation method etc.

求解孤立波方程精确解的方法除了传统的反散射方法、Hirota双线性方法、Backlünd变换方法外，近年来又涌现了很多新方法，如齐次平衡法、双曲正切法，级数展开法等。

The digital speciemen image of adult Helicoverpa armigera Hubner was acquired using a digital camera in an image acquisition environment.Several methods of image enhancement were covered, including linear smoothing, median filtering, linear greylevel transformation, contrast stretching, image inversing and histogram equalization. Results demonstrated that these methods evidently enhanced the speciemen image of H.

digital image ；本研究以棉铃虫成虫标本作为数字图像源，设计了图像获取环境，以数码相机做为数字图像获取设备获得了棉铃虫成虫的数字图像，介绍了昆虫数字图像增强的方法，包括图像的线性平滑、中值滤波平滑、线性灰度变换、对比度拉伸、图像求反以及直方图均衡化等增强方法，证明这些方法对棉铃虫图像具有明显的增强作用。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。