Aiming to the key problem of how to divide gray scale intervals in segmental linear transformation method , this thesis puts forward a method based on region segmentation transformation . it accelerates the process of adjusting gray intervals and improves the efficiency of carrying out the arithmetic 对于分段线性变换方法中如何划分灰度区间进行变换的问题,给出了基于区域分割变换方法,加快了调整灰度区间的过程,提高了算法的执行效率。
Firstly , several methods are used to test if there is heteroscedasticity in the data . then some variance stabilizing transformation methods are applied to the data . finally , it is pointed out that the least squares fitting may be used to the transformed data 先用几种方法对数据是否具有异方差性进行检验，然后选择适当的方法进行变换，最后指出，可以通过对新模型作最小二乘拟合等方法，观察变换后的模型其数据的拟合程度，以确定模型的优劣。
Secondly , aiming at measurement being only from one satellite and the ekf being not stable , the measure equation is improved . transforming the form of angle measurements by the imaging theory , linearization of measure equation is realized by fake data of measurement . parameter of ballistic missile trajectory is estimated by using ekf , and the simulation shows that the unstabilization problem of ekf with true measurements is solved by using ekf with fake measurements 在仅有一颗预警卫星能够观测到目标的情况下,针对扩展卡尔曼滤波不稳定的问题,对观测方程进行改进,利用光学成像系统的原理,将测量量进行变换,并利用新生成的伪测量量使测量方程线性化,再利用扩展卡尔曼滤波算法对目标的弹道参数进行估计,最后,通过数学仿真来证明利用伪测量量的扩展卡尔曼滤波解决了单颗卫星观测时利用真实测量量的扩展卡尔曼滤波不稳定的问题。
The technology for three - phase cycloconverter has broad background in industry application . the common mode of its usage is to convert the shapes of electronic energy with power transistor elements . the conversion of the shapes of the electronic energy include amplitudes , frequencies , and forms of the voltage or current which can make the shapes of electronic energy suitable for different kinds of electronic equipments 三相交-交变频电源技术是一门应用性很强的技术，其应用的主要方式就是采用功率半导体器件，对电能进行变换?包括电压和电流的幅值、频率和波形等方面的变换，以达到使电能更好地符合各种不同用电设备的要求。
Based on the reference [ 22 ] , the dynamical modeling converters for hvdc system have been transformed to a nonlinear system represented by input - output model with unmodeled dynamics and bounded disturbances , and a robust adaptive output - feedback nonlinear controller is designed . the controller counteracts the uncertain dynamic nonlinearities and bounded disturbances by nonlinear damping terms , and unmodeled dynamics by a dynamic signal 本文在文献[ 22 ]的基础上，对高压直流输电系统换流站动态模型进行变换处理，将其化为一类具有含未建模动态和有界扰动的输入-输出非线性系统，并设计了一种鲁棒自适应输出反馈控制器，利用非线性阻尼项来抑制系统的动态不确定性和有界扰动，引入一动态信号来抑制系统的未建模动态。
A novel communication receiver which uses lapped transform ( lt ) incorporating modified median filter ( mmf ) algorithm is designed for narrow - band interference excision . the lt domain mmf algorithm takes full advantages of the direct sequence spread spectrum signal , as well as the characteristics of lt , performing the transform domain filtering twice . the first filtering locates the position of interference and mitigates most of them . the second filtering is performed in a small neighborhood of the located interference . so lt domain mmf algorithm can completely mitigate the interference without distorting the desired signal . simulation results demonstrate the improved ber performance and increased robustness of our receiver 本文采用改进的重叠变换域中值滤波算法进行变换域抗干扰处理.该算法既考虑到直接序列扩频信号的特点，同时又利用重叠变换的特性对变换域系数进行了二次滤波.该算法节省处理时间，并且不需要有关干扰的先验知识，系统性能不会随干扰频率变化而变化，因而是一种很稳健的处理方法
How to realize it is the necessary stage of bind restoration of remote sense image processing . this paper introduces a way to remove the effects of cloud by frequency transform . here , information of cloud cover is removed by high - pass filtering and information of background is enhanced by homomorphic filtering and spatial - frequency analysis 本文结合中巴资源卫星地面应用系统图像应用处理分系统“课题的需要，采用数字图像变换的方法来去除无辅助信息的遥感图像薄云覆盖，通过对薄云覆盖的遥感图像进行变换域处理，进行高通滤波去除云覆盖所在的低频信息，通过同态滤波并对图像进行空频分析来增强图像背景。
Tl1is paper introduced using wavelet ' s well specialty to process ilnage information and changed zero t ] ree lnetllod to complete compression . lt is an active attempt and discuss about information transmis5iiol1 in underwater acoustic channel . basi11g on the practice require , zeio tree lnethod l1as been changed 本研究介绍了以一幅64 64点阵的彩色图像为基础，利用小波的优良特性对图像信息进行变换处理，并使用改变的零树法进行编码，完成数字化彩色图像信号的数据压缩，对在水声信道中传输彩色图像做出积极的尝试和探讨。
In this paper , chroma dc coefficients are selected as the carrier data because chroma dc coefficients are robust . also , alterable steps are used to select one part of the coefficients , so the watermark is imperceptible ; before watermark embedding , the watermark is divided into many parts , every part is individually embedded into one gop of the video , even if a gop is destroyed , the watermark can be extracted correctly , this methods promotes the robustness of the watermark ; in addition , in order to promote the security of the watermark , the user ' s id and password are used to generate chaos sequence by the chaos system which is created in this paper , later , watermark is mixed by the chaos sequence . also , the embedding position of the watermark bit is modified by one chaos sequence , so , unauthorized person can not extract or remove the watermark , since the embedding position is unknown 本文认为，色度dc系数是鲁棒性非常好的参数，因而选择色度dc系数作为水印信息载体，同时，采用可变的步长选择部分系数，保证了水印的隐形性；在嵌入水印时，本文采用水印信息“网格划分” 、各子块独立嵌入视频的方案，由于水印信息子块是相对独立的嵌入视频中的每一相对独立的图组当中，即使某一图组收到一定破坏，也能够恢复水印信息，使水印的健壮性得到提高；此外，为了提高水印信息的安全性，在嵌入水印信息时，根据用户输入的id号和密码，利用本文构造的混沌系统产生的混沌序列对水印信息进行变换，同时，对每一水印信息比特的嵌入位置也采用了伪随机序列进行调整，这样，未授权用户不能提取水印信息，也难以擦除其中的水印信息，因为嵌入的位置是未知的。
