协方差

It is proved that the least squareestimators of linear estimable functions of regression coefficients areadmissible under matrix loss and minimax. The necessary and sufficientexistence conditions are derived for the uniformly minimum riskequivariant estimators of linear estimable functions ofregression coefficients under an affine group and a transitive group oftransformations respectively. It is also proved that there are no UMREestimators ofthe covariance matrix and variance under an affine groupof transformations and quadratic loss functions.

本文证明了回归系数的线性可估函数的最小二乘估计是极小极大的且在矩阵损失函数下是可容许的；还分别在仿射变换群和平移群下导出了存在回归系数的线性可估函数的一致最小风险同变估计的充要条件，并证明了在仿射变换和二次损失下不存在协方差阵和方差的 UMRE 估计。

To improve the precision of tree biomass parameter calculation, this paper explicates the principle, method and process to estimate the parameters of tree biomass by the nonlinear least square according to the formula of allometry method. It gives the formula to calculate the variance and covariance estimated parameters, and reveals the essence of logarithmic linearization regression of power function.

为了提高林木生物量参数的计算精度，根据林木相对生长公式，阐述用非线性最小二乘法求解生物量参数估值的原理、方法和过程；给出计算参数估值之方差与协方差的公式；揭示幂函数对数线性化回归的本质。

Analysis of covariance is a combination of regression analysis and variance analysis.

协方差分析足把直线回归与方差分析结合起来应用的一种方法。

We discuss asymptotically best linear unbiased estimators of the Logistic population based on selected order statistics and give the formula of computing the ABLUE, the variance and the covariance of the ABLUE in limit, and properties of the ABLUE, and so on. We give the optimum chosen of spacing which is the ABLUE with maximum asymptotic relative efficiency based on complete sample when selected order statistics number is less than 10, and obtain its maximum asymptotic relative efficiency.

讨论基于Logistic总体Ⅱ型截尾样本的若干个样本分位数的总体分布参数的近似最佳线性无偏估计；给出了该近似最佳线性无偏估计的计算公式，估计方差与协方差的极限表达式及估计量的大样本性质等；给出了全样本，样本分位点个数固定，但不超过10情形下，使上述近似最佳线性无偏估计有最大相对联合估计效率时，样本分位数选取法及最大相对联合估计效率；为大样本情形下，该近似最佳线性无偏估计的应用提供了理论依据。

The sample covariance between each independent variable and the OSL residuals is zero.

每个自变量和OLS协残差之间的样本协方差为零。

In other words, on the basis of known low space resolution multi-spectral image and high space resolution panchromatic spectral image, it will simulate to create high space resolution multi-spectral image.

针对这一应用目的，本文在对现有的定性定量指标分析的基础上，设计了一组适合本文的评价标准，就是在目视判读的基础上，采用平均梯度和小波能量分析融合影像和原始未降解的多光谱影像的空间分辨率差异，采用标准方差、标准偏差和协方差矩阵行列式值分析融合影像和原始未降解的多光谱影像的信息差别，采用均值、中值和归一化最小方差分析融合影像的光谱信息保持程度。

A 8×2×3 ( 8 subsistence strategies: agricultural, irrigation, fishing, hunting, forest industrial, city industrial, and trading/man and woman/18- 34 years of age, 35-49 years of age, and above 50 years) ANOVA with covariable(the influences of modernization)revealed significant covariable effect and main effect of subsistence strategy, sex and age in the analysis operation, significant covar-effect and main effects of subsistence strategy and age in the connection operation, significant covareffect and main effects of subsistence strategy in cognitive style.

认知测试分数的8×2×3的ANOVA协方差分析表明，在分析操作水平上存在着显著的组间差异、性别差异、年龄差异和协变量的效应；在综合操作上，存在着显著的组间差异、年龄差异和协变量效应；在认知方式上，存在着显著的组间差异和协变量效应。

The new statistical analysis methods are mostly based on mixed linear model approaches for estimating variances and covariances, unbiasedly predicting random effects, analyzing conditional variaces and effets, and composite interval mapping.

基于混合线性模型的分析原理的统计分析方法包括方差和协方差估算方法、随机效应的无偏预测方法、条件遗传方差和条件遗传效应的分析方法、复合区间作图方法等。

By the modem time series analysis method, based on the ARMA innovation model, under the linear minimum variance optimal information fusion criterion, three distributed fusion steady-state optimal Kalman filters, predictors and smoothers weighted by matrices, scalars, and diagonal matrices are presented for multisensor systems with correlated input and observation noises, and with correlated observation noises. The Lyapunov equations and formulas of computing local filtering, predicting and smoothing error variances and covariances are given, which are applied to compute optimal weights. The corresponding three distributed fusion Wiener state estimators are also presented.

应用现代时间序列分析方法，基于自回归滑动平均新息模型，在线性最小方差最优信息融合准则下，对于带相关输入噪声和观测噪声和带相关的观测噪声的多传感器系统，提出了按矩阵加权、按标量加权和按对角阵加权的三种分布式融合稳态Kalman滤波器、预报器和平滑器，其中提出了局部滤波、预报和平滑估值误差方差阵和协方差阵的Lyapunov方程和计算公式，它们被用于计算最优加权，也提出了相应的三种分布式融合Wiener状念估值器。

Due to the possibility of reducing risk through diversification, the risk of portfolio, measured as its variance , will depend not only on the individual variances of the return on different assets, but also on the pairwise covariances of all assets.

风险可以用方差来衡量，通过分散化可以降低风险。投资组合风险不仅依赖不同资产各自的方差，而且也依赖资产的协方差。

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