查询词典 sample covariance

The commons among those methods is that all of them calculate the mean vector and the covariance matrix of sample then calculate other variables by using them.

这些方法有个共同的地方就是都会计算样本的均值向量和协方差矩阵，并在这两者的基础上计算其他统计量。

It describes the heteroskedasticity character of interest rate by projecting the sample data onto the EGARCH (1, 1) auxiliary model, makes making the covariance matrix as moment conditions and uses EMM to estimate the parameters. EMM avoids the disadvantage of infeasible or computationally intensive of maximum likelihood functions.

通过将观测数据映射成EGARCH(1， 1)辅助模型描述利率行为的异方差特征，以协方差矩阵为矩条件，用有效矩估计方法得出模型参数，避免了最大似然估计法似然函数不可知或难以求积分的缺陷。

Mapping ordered eigenvalue points of sample covariance matrix of the observation data onto Hough parametric space,the number of eigenvalues of noises can be estimated by detecting the peak points on Hough parametric space,and thus the number of signal source is determined.

该方法通过Hough变换将观测数据的采样协方差矩阵的排序特征值点投影到Hough参数空间，通过检测Hough参数空间中积累的峰值来估计噪声特征值的数目，从而确定信源的个数。

In this dissertation, we develop the research work of the following three aspects based on existed work.First, using the scale-invariant property of multiscale model, i.e. Markovian among scales, a method of qth-order tree-based for multiscale representation of a class of 1-D stochastic process is presented. The multiscale stochastic model is established. The representation forms of parameter matrices, such as, the state transition matrix, the disturbance matrix, the initial state and the corresponding covariance matrix are deduced in detail. The multiscale sample paths based on distinctive order tree are presented by computer simulation.

本文在已有工作的基础上，开展了以下几个方面的研究工作： 1、根据多尺度模型尺度不变性，即利用尺度间的Markov性，给出了一类1-D随机过程基于一般q阶树的多尺度表示方法，建立了相应的多尺度动态模型，详细推导了多尺度模型中的状态转移阵、扰动阵、初始状态和相应的协方差阵，并通过计算机仿真给出了不同阶树的多尺度采样路径。

Point estimation is the estimation of the mean, variance, and covariance of a random variable from sample data.

点估计是样本数据随机变化的方式，差异，协方差的估计。

The second eigenvalue of the sample covariance matrix of dual-channel SAR data can effectively indicate the ground moving targets.

利用双通道合成孔径雷达(synthetic aperture radar， SAR)数据的协方差矩阵的第二特征值，可以有效地检测地面运动目标。

However,for the large dimensional data.the sample covariance matrix is not a good estimator of the population counterpart.Many methods of parametric estimations and tests for multivariate statistical problems can not be simply used to deal with large dimensional data.

但是由于经典的大样本理论都是假定维数很小是固定的，故而经典极限理论并不适宜解决大维随机数据问题，很多多元问题的模型参数估计、模型检验的统计量已有的结果对大维海量数据并不能平凡推广。

The algorithm processes very few snapshot data opposed to forming sample covariance matrix and computing matrix inversion.

它无需构造协方差矩阵及进行矩阵求逆，又避免了复杂度较高的广义特征值分解。

While the LCLS method is used to minimize the energy of the linearly fused information, the neural-network algorithm is developed to overcome the ill-conditioned and singular problems of the sample covariance matrix in the LCLS method.

LCLS方法用来最小化线性融合信息的能量，而神经网络算法则用来处理出现于LCLS方法中的样本协方差矩阵的不良条件和奇异性问题。

In the case where the sample covariance matrix is given, we perform the spatially smoothed Lanczos algorithm to fast compute the basis vectors for the signal subspace and the noise subspace.

如果阵列协方差矩阵是已知的，我们采用空间平滑的Lanczos算法快速估计信号子空间和噪声子空间。

Salt is good, but if the salt becomes flat and tasteless, with what do you season it?

14：33 盐本是好的，盐若失了味，可用什么叫它再咸呢？

He reiterated that the PLA is an army of the people under the leadership of the Communist Party of China.

他重申，人民解放军是在中国共产党领导下的人民军队。