协方差

Precision estimation is made more reliable using error calculation by the law of covariance propagation.

采用协方差传播律进行误差计算，使精度评定的结果更加准确。

An online mixture of experts is used to divide the HRRP data into several regions within which online Gaussian process classifier make predictions.

通过一种在线混合专家将HRRP数据在线地分割成若干个近似平稳的区域，在各个区域内使用平稳协方差函数的在线高斯过程分类器。

The generalized influence function and generalized Cook distance were used to study local influence of observations on the parameter estimates in the growth curve model with uniform covariance structure.

利用广义影响函数和广义Cook统计量来研究具有均匀协方差结构的曲线增长模型的局部影响问题。

Generalized influence function ; generalized Cook distance ; growth curve model ; uniform covariance structure ; diagnostics

广义影响函数；广义Cook统计量；曲线增长模型；均匀协方差结构；诊断

The premise of the superiority of the conventional statistical STAP is to have ample training samples with interference that are independently and identically distributed with interference in the test sample, in order to estimate the covariance matrix.

常规的统计STAP方法性能最优的前提条件是具有足够的与待检测样本中的干扰独立同分布的训练样本，以便估计协方差矩阵。

In the beamformer based on sample covariance matrix inverse algorithm, the calculation of weight vector comprises the components of interferences and noise. The projection method comprises the components of interferences. It induces the imperfective results of the beamformer.

摘要基于协方差矩阵加权的波束形成方法在计算加权向量时引进干扰和噪声的影响，投影方法在计算加权向量时引进干扰信号的影响，这些都造成了波束形成效果的不理想。

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。

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。

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。