查询词典 sample covariance

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 paper consists of three parts. First, we give the calculation for every order central moment for the Logistic population, mean vector and covariance matrix of the order statistic of random sample from the Logistic population, and means of several special functions for the order statistic of random sample from the Logistic population. Secondly, we discuss the parameter estimation for the Logistic population. Finally, we solve the question about the goodness-of -fit test for the Logistic population.

研究的主要内容分三部分：第一部分是关于Logistic总体各阶中心矩、样本次序统计量期望向量与协方差阵及若干个特殊的样本次序统计量函数期望的计算问题；第二部分是关于Logistic总体分布参数的估计问题；第三部分是关于Logistic总体的拟合优度检验问题。

This thesis has mainly contributed two results in theory: one is that the covariance matrix is not positive definitive if the number of sampling is least than the number of variables, the other is that the covariance matrix of discrete sample is positive definitive if and only if the sum of every random column vector of data matrix is non I-linear combination.

本论文在理论上，主要得出两个新的结果：ⅰ抽样调查中，若样本的个数少于变量的个数则样本协方差矩阵恒为非正定；ⅱ离散型样本协方差矩阵正定的充要条件是样本资料阵的各随机列向量是非I-线性组合。

This result has extended the positive definitiveness of covariance matrix of continuous sample in theory.

从而本论文推广了连续型样本协方差矩阵的正定性。

Traditional multivariable analysis method, for example, principal component analysis method and factor analysis method, are common in calculating the mean vector, the covariance matrix of sample and other variables.

摘要传统的多元统计分析方法，如主成分分析方法和因子分析方法等的共同点是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。

However, these methods are estimated according to sample variance and covariance estimators of returns.

然而，这些方法都是根据样本的变异数或报酬的共变异数估算的估计值。

This thesis discussed the positive definitiveness of the covariance matrix of sample whose variables are discrete data by using p-vector match, I-Linear combination and their properties.

对于变量取离散数据的样本协方差矩阵的正定性，很少有学者进行研究。

Based on the previous fault possibility distribution kept within the sample mean and covariance matrix with forgetting factors,a strategy for constructing the target output of the new training sample set was ...

该算法通过带有遗忘因子的样本均值和样本协方差矩阵保存样本所包含的故障可能性分布信息，并在此基础上产生新增样本的目标输出，用于训练FBF网络，以实现故障分类边界的在线跟踪。

First we construct a covariance matrix from sample images, then compute the eigenvalues and corresponding eigenvectors of the covariance matrix, construct a feature matrix with the eigenvectors. Then every images in database can be projected into the feature matrix and gain a projection vector, so does the input image. Then we can judge the resemblance between input image with each image in database by computing the distance between their projection vectors.

我们首先根据采集的样本图像构造一个协方差矩阵，然后求取该矩阵的特征值，以这些矩阵特征值对应的特征向量构造出一个特征空间，然后将输入图像向该特征空间映射，将获取的映射系数与样本库中图像的映射系数进行距离计算，根据计算出的距离判定输入图像与样本图像间的匹配程度。

Based on moving least squares surface, the differential properties of each sample point on PSO are first evaluated. In terms of covariance analysis, the elliptical splat of sample point is then determined on its tangent plane. Finally, the splats are rendered from far to near by using elliptical weighted average filtering. According to the differential properties, moreover, the suggestive contours of PSG are attained so that non-photorealistic rendering of PSG is realized.

首先根据构造的移动最小二乘曲面计算采样点的表面几何属性，然后根据协方差分析确定点元在其切平面上的椭圆表示，最后采用椭圆加权平均滤波从远到近单遍绘制各点元，此外，根据表面几何属性确定点模型的轮廓线，实现了点模型的非真实感绘制。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。