查询词典 transform

The examples show that harmonic wavelet packets transform more excellent than dyadic wavelet transform, and more excel in noise filter based on Fourier transform in sampling rotating vector analysis about vibrational signal on the basis of harmonic wavelet packet transform is putted forward.

实例表明，谐波小波包变换对强噪声下信号的提取能力优于二进小波变换，更优于基于Fouriar变换的噪声滤波。

A method of the optical image encryption based on the frequency splitting domain and Fresnel domain is proposed, after the analysis of the fractional Fourier transform and Fresnel transform, by synthesizing the advantages of multi keys and lensless feature of the fractional Fourier transform and Fresnel transform in the optical image encryption system.

结合分数傅里叶变换及菲涅耳变换，在光学图像加密系统中分别具有多密钥性和无透镜性的优点，提出了基于分频域和菲涅耳域的光学图像加密方法。

Many new detection techniques are proposed, that include: To overcome the faults of cross-terms and short unambiguity range for the common Wigner-Ville Distribution , short-time Fourier transform and Gabor transform are applied to SAR moving target detection. To improve the detection performance of WVD in noise environment, a new technique based on the Cross-WVD is proposed. The application of fractional Fourier transform to chirp signal detection is analyzed and extended to SAR moving target detection. To eliminate the restriction of chirp-Fourier transform, a new modified definition is proposed and applied to SAR moving target detection. To detect multiple moving targets whose scattering intensities are different heavily, the CLEAN technique is combined with the above techniques and the ideal detection performance is achieved. At last, the whole dissertation is concluded.

具体的研究成果如下：针对常用的Wigner-Ville分布在多目标情况下存在交叉项，并且多普勒不模糊范围小的缺点，提出将短时Fourier变换和Gabor变换应用于SAR运动目标检测，分析了其优势所在；为进一步提高Wigner-Ville分布低信噪比条件下的信号检测能力，提出基于互Wigner-Ville分布的运动目标检测方法；分析了分数阶Fourier变换在线性调频信号检测中的应用，提出基于分数阶Fourier变换的运动目标检测算法；对离散Chirp-Fourier变换的定义进行了修正，提出修正的离散Chirp-Fourier变换，克服了限制其应用的约束条件，并用于SAR运动目标检测当中；强度相差较大的多运动目标检测历来是机载SAR技术的一个重点和难点，我们将CLEAN思想融入上述多种算法当中，良好地解决了该问题。

We can see from the existent technology of the natural gas transform, the routs of methane transform include two kinds: direct transform and indirect transform.

因此，我国对天然气的转化催化技术进行研究具有重大的战略意义。

To increase the security of the watermark, a new binary image encryption algorithm based on TD-ERCS map is presented. The watermark is encrypted by a chaos sequence generated by TD-ERCS map; A novel color image watermarking algorithm is proposed based on discrete chaotic map and 2-dimensions discrete wavelet transform. The watermark is encrypted by the new binary image encryption algorithm, and the encrypted watermark is embed into four sub-bands of the most deep level of blue branch of host image by three-level wavelet transform, and the embedded positions are determined by general cat cha otic map; A novel color-image blind detection watermarking algorithm is proposed based on integer wavelet transform and subsampling. The scrambled watermark is encrypted and embed into the low sub-bands after four sub-images of the Y branch of host image is transformed by two-level wavelet transform, and the embedded positions are determined by Logistic chaotic map, this watermarking scheme can realize blind extraction.

为了提高水印图像的安全性，提出了一种基于TD-ERCS混沌映射的二值水印图像的加密算法，该算法利用TD-ERCS映射产生的混沌序列加密水印图像；将离散混沌映射和二维离散小波变换相结合，研究了彩色图像水印新算法，该算法先对混沌序列加密后的水印图像进行小波变换，再嵌入到宿主图像的蓝色分量的最深层的四个子带中，嵌入位置则由广义猫映射确定；将整数小波变换和图像子采样技术应用于数字水印，提出了一种彩色图像盲提取水印算法，水印嵌入时，先对宿主图像在YIQ色彩空间中的Y分量进行子采样，并对得到的四个子图像分别进行二级离散小波变换，然后将置乱并加密后的水印图像嵌入到小波变换后的低频子带中，其嵌入位置由Logistic混沌映射产生的混沌序列确定，实现了水印的盲提取。

On the basis of wavelet transform and S transform,through popularizing basic wavelet, the basic wavelet containing 4 kinds of unknown parameters (amplitude, energy attenuation rate, energy-delay time and apparent frequency ) was constructed, realizing generalized S transform.

在小波变换和S变换基础上，通过对基本小波的推广，构建含有四类待定参数(振幅、能量衰减率、能量延迟时间及视频率)的基本小波，实现广义S变换。

According to the Poisson equation of gravity-magnetic potential, we derive the relation of cosine transform spectrum between magnetic potential and magnetic field constituent and deduce the cosine transform spectrum formula of n degree derivatives using the cosine transform.

根据重磁位场的泊松公式，利用余弦变换给出磁位与磁场分量间的余弦变换谱关系，推导出磁异常n阶导数的余弦变换谱公式。

Chaper 3 is general description of ADA encryption. Chapter 4 deals with the transform domain encryption. Includes the element of perfect and quasi-perfect transform domain encryption, and presents two type new schemes. Chapter 5 deals with asynchronous ADA encryption. Extends the general theory and model of asynchronous ADA scrambling, and introduces two type phase-distortion-free a synchronous ADA schemes. Chapter 6 is about new direction of ADA encryption. Includes TASI scrambling, transform domain dummy insertion scrambling, noise coving scrambling and other multi-dimension ADA scrambling, and proposes an adaptive dummy spectrum insertion asynchronous scrambling and a new adaptive noise-coving DFT scrambling algorithm. Chapter 7 is on permutation key. presents part results on permutation features, selecting criterion and constructing method. Chapter 8 introduces the hard and software design of a common ADA encryption/decryption system, and presents the experimental results on several proposed ADA encryption schemes.

第一章为绪论；第二章为语声信号、及其处理基础；第三章为模数模加密的一般描述；第四章为变换域加密研究，包括变换域加密机理，变换域完善与准完善保密研究，提出两种新的变换域加密方案；第五章为异步模数模加密研究，扩充了异步模数模加密的一般理论，介绍了两种新的无相位失真异步加密方案的原理与实现方法；第六章对模数模加密新方向：TASI应用途径、变换域伪谱插空置乱、噪声掩盖、多维置乱加密的原理和方法进行介绍，提出了自适应伪频插空异步模数模置乱算法与自适应DFT系数噪声掩盖置乱新算法；第七章为置换密钥性质、筛选准则以及构造方法研究的部分结果；第八章介绍了通用模数模加/解密实验系统的硬件、软件研制概况，并给出了几种加密方法的实验结果。

All phase Walsh transform ; biorthogonal transform ; dual biorthogonal base vectors ; JPEG image compression algorithm ; discrete cosine transform; peak signal to noise ratio

全相位沃尔什变换；双正交变换；对偶双正交基向量； JPEG压缩编码算法；离散余弦变换；峰值信噪比

Results The clouds can be effectively removed by applying the Convolution Operation、Fourier Transform, Fourer Transform Editor、Inverse Fourier Transform and Tasseled Cap; The cloud shadow can be removed by applying the Haze Reduction and Principal Components Analysis.

结果 利用空间卷积运算、傅立叶变换、傅立叶图像编辑、傅立叶逆变换组合和缨帽变换的方法有效地去掉了试验区图像上的云层；利用去霾处理和主成分分析方法按一定顺序组合将有效地去除云层的阴影。

But this is impossible, as long as it is engaging in a market economy, there are risks in any operation.

但是，这是不可能的，只要是搞市场经济，是有风险的任何行动。

We're on the same wavelength.

我们是同道中人。