We develop some methods for evaluating the security of lsb steganography using randomness test and two-dimension self-correlation function . 4 ) evaluation of the statistical visibility of information hiding algorithms 提出了基于二维自相关函数径向谱和随机性检验(包括顺序检验、游程检验和一维自相关检验)的lsb信息隐藏安全性评估方法。
The expressions for correlation functions, power spectrum and correlation time of the intensity of a single-mode laser driven by two white noises with a exponential function correlation form were calculated by linear approximation method 应用线性近似方法,计算了具有指数形式关联的两白噪声驱动下单模激光光强的关联函数、功率谱及关联时间。
In order to make algorithmbe robust against noise, some improved methods was presented such as adaptive cen-troid estimation algorithm, complete correlation function algorithm and adaptive cor-relation function algorithm 为了使算法对噪声干扰具有鲁棒性,在这两类方法的基础上,又提出了自适应质心估计算法、完全相关函数法以及自适应相关函数法等改进方案。
This method uses two spatially separated receiving equipment . cross correlation of the two outputs will therefore yield the auto correlation function ( acf ) of the signal, plus noise which is spread uniformly over the whole width 该算法采用空间上分离的两路接收设备,通过对包含同一个信号的2个输出信号互相关,得到信号窄自相关函数(acf)和在整个带宽里均匀分布噪声成分。
The quantitative expression for speckle correlation function is formulated, in which the scattered intensity profile reciprocated on the surface plane acts as the aperture function in van cittert-zernike theorem 我们首先得出了散斑相关函数的定量表达式,该式表明散斑相关函数实际上是在vancittert-zernike定理中等效地将散射轮廓函数反演到散射体平面内作为散射孔径函数的结果。
We deduce the correlation functions of order parameter by hyperboloid function ( t > tc, t < tc ), and then compare the two functions to get the change of specific heat, and to get correlation length ? as the token of correlation degree 利用残数定理分别求tt_c,tt_c时的关联函数,发生相变时比热的跃变,找到表征关联的特征量??关联长度,进一步确定landau理论的适用范围。
Analyze window shows the four important data : amplitude of the played chirp ( white ), amplitude of the received sound ( red ) from microphone, correlation function of the microphone signal ( green ) and absolute values of correlation function ( yellow ) 分析窗口展示四个重要数据:被演奏的短促声波的高度(白色),被接受的声音的高度(红色)从话筒,话筒信号的相关函数(绿色)和相关函数的绝对值(黄色)。
Analyze window shows the four important data : amplitude of the played chirp ( white ), amplitude of the received sound ( red ) from microphone, correlation function of the microphone signal ( green ) and absolute values of correlation function ( yellow ) 分析窗口展示四个重要数据:被演奏的短促声波的高度(白色),被接受的声音的高度(红色)从话筒,话筒信号的相关函数(绿色)和相关函数的绝对值(黄色)。
The o . z . equation describes the relation between the direct and total correlation functions, and this relation can be interpreted that the total correlation function of two particles is the sum of direct correlation and indirect correlation transferred by all other particles )方程从直观上是很容易理解的,它表示了系统中任意两个粒子间的总关联是它们之间的直接关联和所有间接关联的总和。
The o . z . equation describes the relation between the direct and total correlation functions, and this relation can be interpreted that the total correlation function of two particles is the sum of direct correlation and indirect correlation transferred by all other particles )方程从直观上是很容易理解的,它表示了系统中任意两个粒子间的总关联是它们之间的直接关联和所有间接关联的总和。