查询词典 covariance

Covariance is used to detect watermark, which may reduce the influence of initial data or chaos in partially.

在水印检测中使用协方差方法，尽可能地减小了原数据或噪声对水印检测的影响。

A vector inner product space defined by covariance is introduced in the above study, which greatly ease the theoretical analyst of principle and performance of image fusion methods.

在这一过程中引入了一种以协方差定义的图像向量内积空间，极大的简化了对融合原理和融合性能的分析。

At last, the Double Message Signal is proposed and the non-interfere condition is presented that the steering vectors are orthogonal in the weighted inner product space, with the inverse matrix of background covariance as the weighting matrix. The optimal polarization states are designed, according to the EM background.

最后，提出了一种双信息信号传输的方案并导出了无互扰传输的充要条件：两期望信号的信号矢量在以干扰噪声协方差矩阵的逆矩阵为加权矩阵的加权内积空间中正交，在给定的电磁环境下设计了双信息信号的极化状态。

Chapter 5 deals with the solvable theorem of adaptive inverse optimal control problems for a class of stochastic nonlinear systems driven by Wiener noises of unknown covariance. The systems are depicted by It〓 stochastic differential equations. By using an adaptive backstepping algorithm and stochastic control Lyapunov functions, the designing procedure of control laws of global asymptotic stability in probability and adaptive inverse optimal stabilization in probability are presented systematically. Adaptive control laws and parameter update laws can be obtained at the same time by this design scheme.

在第5章中，针对具有方差不确定Wiener噪声扰动和未知定常参数的随机非线性系统（假设方差的F—范数是一个常数或一个缓慢变化的量，对其进行在线辨识），给出并证明了自适应逆最优控制问题可解定理，基于随机Lyapunov定理和It〓微分规则，采用自适应Backstepping设计方法，系统地设计了全局依概率渐近稳定和自适应逆最优控制策略，这种设计方法可同时获得控制策略和自适应律，计算机数值仿真结果表明该控制算法是有效性的。

The one order differential model and convolutional model of impedance formula of amplitude versus offset inversion were established. Impedance inversion formula from AVO was derived based on Bayesian framework. Methods of using Huber function as prior model parameter distribution and covariance matrix from well log as constrains were developed. The P-wave impedance, S-wave impedance and density were calculated by the conjugate gradient algorithm.

为此建立了振幅随偏移距变化波阻抗反演公式的一阶差分模型及褶积模型，推导了基于贝叶斯理论的AVO波阻抗反演公式，给出了采用Huber分布作为模型参数的先验分布及测井数据的参数协方差矩阵作为约束条件的实现方法，并利用共轭梯度法计算了纵、横波阻抗及密度。

We will demonstrate the specification of reference prior distribution on the random covariance matrix. We will consider the approximate uniform shrinkage prior and approximate Jeffreys' prior. Both are formulated based on the approximated likelihood function. Under generalized linear mixed models, we show that the posterior mode under Jeffrey's prior is asymptotically closer to the REML estimate than the mode under uniform shrinkage prior does.

在广义线性混合模式下，我们证明了在样本数很大时，随机效应之变异数成份的后验众数和REML估计值会近似相等，同时也建立了后验众数和REML估计值的近似关系式，并提出了比较二种后验众数与REML估计值之间远近的准则。

This thesis mainly discuss following issues, Theory and simple expressions for array covariance matrixes are derived when angular spread functions are symmetric distribution functions, i. e. the Uniform distribution, the Gauss distribution, the Laplace distribution and the Von Mises distribution, and a non-symmetric distribution function, i. e. the Gamma distribution. And the relation between the effective signal subspace and the array number, or and the nominal angle of the distributed source, the angular spread, the distributed functions, and the Signal-to-Noise Ratio is gained. The dimension of the effective signal subspace increases with increment of the array number. And it is more obvious to the non-symmetric distribution. The dimension of the effective signal subspace decreases with increment of the nominal angle. And the distributed source is equal to a point source as θ=π/2. The dimension of the effective signal subspace increases with increment of the angular spread.

本论文针对阵列信号处理中广泛存在的分布源现象，主要讨论了以下问题：推导了角度分布函数分别为对称的均匀分布、高斯分布、拉普拉斯分布、Von Mises分布和非对称的伽马分布时，分布源阵列接收信号协方差阵的严格模型和简化模型，得到了单个分布源的有效信号子空间随阵元数、分布源中心角、分布角、角度分布函数和信噪比的变化规律：随着阵元数的增加，对所有角度分布函数的有效信号子空间维数也随着增加，且非对称分布函数的有效信号子空间充满整个空间的可能性更大；随着分布源中心角逐步增加，有效信号子空间维数逐步减小，当θ=π/2时，等价于点源情形；随着分布源分布角逐渐加大，有效信号子空间维数也随之增加，直到有效信号子空间充满整个空间；随着信噪比的增加，有效信号子空间维数有一定程度的减少。

Taking mapping QTL that affect leaf age growth trajectories in rice of a DH population as an example, we used 3 biological meaningful submodels and 2 orders Legendre polynomial to model the mean vector of QTL genotypes and 11 stationary and non-stationary models to fit residual covariance matrix.

以水稻一个DH群体的叶龄性状为例，我们分别用3个具有生物学意义的子模型和2阶Legendre多项式去拟合QTL基因型的均方向量，用13个平稳和非平稳模型去描述剩余协方差的变化。

Second,Principal component analysis is essentially a linear method based on the covariance matrix which reflects the linear dependence.

用能反映非线性结构的四阶累积量函数代替相关函数构造矩阵，对主分量分析方法进行改进。

The problem of D-stable robust covariance control for the delta operator formulated linear uncertain systems based on dynamic output feedback is studied.

研究Delta算子描述的线性不确定系统基于动态输出反馈的D-稳定鲁棒协方差控制问题。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了