余弦

The binary coding of cosine eliminates zeroth order diffraction theoretically, and can generate high pixel hologram.

余弦二值编码方法从理论上消除了零级衍射，可以制作像素较多的全息图。

Propagation of cosh-Gaussian beams through an apertured ABCD optical system .

双曲余弦高斯光束通过有光阑限制的ABCD光学系统的传输。

In this method, the sine, cosine signal is converted by three line autosyn and its output is a binary code based on AD2S83. The measurement datum can be read and displayed by computer.

着重研究了自整角机的三相信号通过隔离转换电路转换成正、余弦信号，输入到高精度AD2S83的轴角／数字转换电路转换成二进制数字信号，供给计算机系统读数显示。

The computational complexity has been reduced about 5 times over against the original one. Moreover, the interpolation and quantization processing of CW is more reasonable; 2. A secondary power normalization algorithm is proposed in this dissertation. This normalization algorithm ensures that the energy sum of SEW and REW is 1. So, the energy ratio of SEW and REW can be achieved only by using SEW energy. This ratio is applied in REW quantization and CW composition; 3. For more efficient quantization for Slowly Evolving Waveform magnitude, Rapidly Evolving Waveform magnitude and power parameters, firstly, by applying the Equivalent Rectangular Bandwidth theory, classifiable multi-codebooks method, analysis-by-synthesis approach and so on, a predictive AbS multi-codebooks SEW magnitude quantization scheme is proposed. In the scheme, pitch information is exploited to determine which codebook is searched; secondly, for REW magnitude quantization, this dissertation proposed a DCT-matrix multi-codebooks quantization scheme. The classification in muti-codebooks is based on pitch and quantized SEW power. The multi-codebooks structure may offer more the information in quantization and solve the problem of the bit requirement limits in quantization by consuming some extra storage space; Furthermore, for the switch quantization of CW gain, a new classified parameter is proposed.

本文的主要贡献体现为如下几方面：一、为了减少WI模型的计算复杂度，提出了基于快速傅立叶变换、三次B样条插值和周期延拓技术的特征波形(Characteristic Waveform，CW)表示和对齐的快速算法，与原方法相比，计算量下降到原方法的1/5，同时也使得CW在插值和量化时更合理；二、为了严格保证SEW与REW的能量和为1，提出了一种特征波形的二次功率归一化算法，仅需要SEW能量就可以算出二者的能量比，并可应用到后续的REW的分类量化和CW合成中；三、为了对慢渐变波形(Slowly Evolving Waveform，SEW)幅度、快渐变波形(Rapidly Evolving Waveform，REW)幅度和特征波形功率进行有效量化，本文首先采用临界频带理论、分析合成技术、感觉加权技术以及预测式矢量量化技术，提出了一种基于基音周期分类的SEW分析合成预测式多码书量化方法；其次，本文根据基音和量化后SEW的功率信息对REW幅度进行分类，提出了一种基于离散余弦变换的REW矩阵多码书量化方法。

Topographic correction based on sun-canopy-sensor geometry is more appropriate than terrain-based corrections in forest areas because SCS preserves the geotropic nature of trees regardless of terrain, view, and illumination angles.

SCS校正模型解释了树木不依赖于地形、观测角和光照入射角而具有向地性生长的本质特性，但在某些地形区域，SCS与余弦校正同样存在过度校正的问题。

The horizontal and vertical first derivatives of magnetic anomalies of an infinite cylinder are calculated by the cosine transform method, in which the maximum errors are -028 nT/m and 047nT/m, respectively and the percent errors are generally within -357%～327% and -194%～188%, respectively except several data of the boundary and part are bigger because of remains of Gibbus effect. The calculating curve and theoretical curve are approximately coincident, and there is no influence by effective magnetic dip angle in computing.

利用余弦变换法计算的无限长水平圆柱体磁异常水平和垂向一阶导数的最大误差分别为-028 nT/m、047 nT/m；水平一阶导数的误差一般在-357%～327%之间，垂向一阶导数的误差一般在-194%～188%之间；计算的磁异常一阶导数值与理论值大致重合，而且不受有效磁化倾角的影响。

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%。

The horizontal and vertical first derivatives of magnetic anomalies of an infinite cylinder are calculated by the cosine transform method, in which the maximum errors are -0.28 nT/m and 0.47nT/m, respectively and the percent errors are generally within -3.57%~3.27% and -1.94%~1.88%, respectively except several data of the boundary and part are bigger because of remains of Gibbus effect. The calculating curve and theoretical curve are approximately coincident, and there is no influence by effective magnetic dip angle in computing. But the errors with the Fourier transform method are -10.62nT/m and 14.42nT/m, there is large departure between the calculating curve and theoretical curve and evident influence by effective magnetic dip angle in computing.

利用余弦变换法计算的无限长水平圆柱体磁异常水平和垂向一阶导数的最大误差分别为-0.28nT/m、0.47nT/m；水平一阶导数的误差一般在-3.57%~3.27%之间，垂向一阶导数的误差一般在-1.94%~1.88%之间；计算的磁异常一阶导数值与理论值大致重合，而且不受有效磁化倾角的影响而Fourier变换法计算的水平和垂向一阶导数最大误差分别为-10.62nT/m、14.42nT/m，计算曲线与理论曲线偏离大，受磁化倾角的影响也较大。

For fast orthogonal transformation algorithm, the paper carries out detailed research and analysis. In terms of many transform coding, it put forward these four rapid transformation algorithms which are Discrete Cosine Transform, Discrete Fourier Transform, Harr Transform, Walsh-Handmaid Transform, and analysis of these fast algorithms in image compression applications.

对于正交变换的快速算法本文进行了详细的研究与分析，并根据各种变换编码，提出了离散余弦变换、离散傅立叶变换、Harr变换、Walsh-Hadamard变换这四种变换的快速算法，并分析了这些快速算法在图象压缩中的应用。

This method uses what Professor Salton has proposed as the vector spacial model to express text as an invisible vector in hyperspherical space.It makes use of certain pre-disposal methods (reduce the dimensions,clustering thesaurus,filtering out old-fashioned words) to reduce the dimensions.It usescosines to measure the degree of similaritybetween texts and uses the total similarity as the target convergence vector.It produces clustered results by using restricted iteratives to achieve partial perfection.

该算法用Salton教授提出的向量空间模型把文本表示成不可视的超球向量空间的一个向量，采用一定的预处理手段(降维、同义词归并、停用词过滤)完成维数约减，使用余弦相似度度量文本之间的相似度，并选择总凝聚度作为目标收敛函数，通过有限次的迭代达到局部最优，输出聚类结果。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。