协方差

In this paper,an improvement is made through selecting a group of normal orthogonal vectors in feature subspace,to generate large amount of virtual training samples.

在模式特征子空间中选取一组标准正交向量，使用这组向量可以生成大量的虚拟训练样本，从而实现对协方差矩阵的优化。

In this paper, an improvement is made through selecting a group of normal orthogonal vectors in feature subspace, to generate large amount of virtual training samples.

摘要在模式特征子空间中选取一组标准正交向量，使用这组向量可以生成大量的虚拟训练样本，从而实现对协方差矩阵的优化。

Phase screen which has same statistics as turbulence-induced atmospheric phase (vonKarman and Kolmogorov spectrum) will be generated by covariance method using pulse function as an orthonormal basis function.

提出正交基为冲激函数的协方差法，在Matlab中仿真实现符合大气湍流统计分布（vonKarman谱和Kolmogorov谱）的大气相位屏。

Chapter 3: we construct a general model of covariance-adjusted duration-convexity immunization to hedge the interest rate risk in the situation that the yield curve doesnt parallel shift and then analyse the model in the case of hedging portfolios of two assets and three assets.

第三章建立一个基于协方差调整的一般久期-凸度免疫模型，用于收益率曲线非平行变动情形下对冲利率风险，并用两资产对冲组合和三资产对冲组合进行特例分析。

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。

In chapter 4, the case of risk asset allocation with allowed sell and restricted short sell is discussed, especially in case of restricted short sell, the efficient frontier piecewise partition is determined by using duality theory in parametric quadratic programming. And the concept of tripartition is introduced, economic meaning stated and algorithm to determine efficient frontier proposed.

特别对限制卖空的证券组合，应用参数二次规划对偶性理论解决了有效边缘曲线分片划分的问题，并引入了三元分割的概念，解释其经济意义，同时给出确定有效边缘的算法；对于协方差矩阵是奇异的情况，利用矩阵分块技术，得到不同情形下有效边缘的解析表达式，并用直观的几何图形描述，克服了M-V模型在实证分析中遇到的困难。

We aimed to assess whether metabolic brain imaging combined with spatial covariance analysis could accurately discriminate patients with parkinsonism who had different underlying disorders.

本研究的目的是评估代谢脑显像与空间协方差分析相结合是否能准确的识别有不同潜在病变的帕金森综合征患者。

The statistical difference of proinsulin rather than HOMA index was found among the patients of various Gensini's score group (Gensini's score was examined as a categorical variable classified by tertile values) and significantly stenosed vessels group by means of the results of analysis of covariate variance after adjusting for age, sex and body mass index (p＜0.05), and the partial correlation coefficient between proinsulin level and Gensini's score, the number of significantly stenosed vessels after adjusting for age, sex and body mass index was 0.3156 (P＜0.01) and 0.2752 (P＜0.05) respectively. Multivariate linear regression analysis indicated that the level of proinsulin was positively correlated with the Gensini's score (P＜0.01). The results of multivariate stepwise Logistic indicated that the proinsulin was the independent risk factor for the coronary heart disease, and the odds ratio (95％ confidence interval) was 2.268 (1.253～4.105)(P=0.007), however, the HOMA was refused by the final model.

年龄、性别与体重指数为控制变量的协方差分析结果显示，胰岛素原的水平在不同的Gensini评分组、冠状动脉病变血管数分组中分布有统计学差异(P＜0.05)，偏相关分析示胰岛素原的含量与Gensini评分与病变血管数显著正相关，其偏相关系数分别为0.3156(P＜0.01)与0.2752(P＜0.05)，而HOMA指数与两种评分的相关未有统计学意义；多因素线性逐步回归分析结果示胰岛素原水平与Gensini评分独立正相关(P＜0.01)；多因素Logistic回归分析显示，胰岛素原的水平为冠心病的独立的危险因素，其OR值及其95％可信区间为2.268(1.253～4.105)(P＜0.01)，HOMA指数未进入模型。

The correlation between lung function and different measure index was compared with covariance analysis and partial correlation analysis.

选取马鞍山市部分初三毕业生进行人体测量和肺功能检测，利用协方差分析和偏相关性分析计算肺功能与不同测量指标的相关关系。

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。

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