查询词典 covariance

A new non-linear quadratic programming Bayesian prestack three-terms inversion method is developed; Firstly, this method is based on Bayesian parameter estimation theory, Gaussian distribution is used for likelihood function and modified Cauchy distribution is used for prior distribution; Secondly, covariance matrix is used to describe the degree of correlation between the parameters; rock physics relations are used to constrain the inversion results; at last, this method is transformed into non-linear quadratic programming problem, and inversion results are acquired under several constraints.

本文提出了一种基于非线性二次规划的叠前三参数反演方法。首先基于贝叶斯参数估计理论，假设似然函数服从高斯分布，并使待反演的参数服从于改进的Cauchy分布，从而提高了反演结果的分辨率；其次用协方差矩阵来描述参数间的相关程度，进一步提高了反演结果的稳定性；最后将问题转化为一个非线性二次规划的求解问题，并在多种约束下得到问题的解。

In order to examine the precision of estimated auto-regressive coefficients, the covariance expression of the estimated auto-regressive coefficients is established using central limit theorem.

为考察AR系数估计的精度，利用中心极限定理建立了估计的自回归系数矩阵协方差的表达式。

In order to examine the precision of estimated auto-regressive coefficients,the covariance exprcssion of the estimated auto-regressive coefficients is established using central limit theorem.

为考察AR系数估计的精度，利用中心极限定理建立了估计的自回归系数矩阵协方差的表达式。

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。

According to supervise and compute the velocity of means and covariance of innovation sequence by BP Neural Network online, a group of weighting coefficient is exported to modify the innovations. Accordingly, the innovations' effect is restrained effectively.

通过BP网络对新息序列的方差和均值的速率进行在线实时监测计算，输出一组加权系数对新息做修正处理，从而有效地抑制了野值对滤波器的影响。

Only two papers known to the author discussed the possible relationship between the estimates of Km and Vmax. Colquhoun (196 9) found a strong positive correlation between these estimates in a simulation study. Subsequently, Oliver (1970) examined this relationship by the asymptotic variance-covariance matrices. These simulation and mathematical analyses were based on the assumption that the substrate concentration is error-free, with the error confined to the reaction velocity. In addition, their work was confined to the several estimation methods.

就作者所知，在本研究发表之前仅有两篇文章讨论过估计值之间的相关性。1969年，Colquhoun通过计算机仿真，发现了估计值之间存在正相关关系，1970年，Oliver用渐近方差-协方差矩阵检验了这一点，但是他们的发现有很大的局限性，其一是限于仅反应速度的测量值有误差这一种情况，其二是限于某几种估计方法。

Variance component model of the random effects of covariance matrix unit for the "Linear model introduction" matrix has been studied.

方差分量模型的随机效应的协方差为单位阵时《线性模型引论》已进行研究。

Longitudinal and correlated data are commonly modeled with generalized linear mixed models which contain both fixed and random effects. The source of the random effect may come from the genetic heredity, familial aggregation, or environmental heterogeneity. The inference of its variance component is usually difficult due to the dimension of its covariance matrix and the complexity of the likelihood function.

在生物医学统计中常接触到具有相关性的资料，这些相关性可能是基因、环境、重复测量或是时间所造成的；在这一类型的研究中，我们通常不只对治疗的效用有兴趣，观测值的变异以及观测值之间的相关性亦可能是我们所关注的量，这些变异或相关形式都可以被称为变异数成份。

Furthermore,the characters of fitted model using matrix of covariance and correlation coefficient were also discussed in this paper

同时，本文还讨论了用协方差矩阵和相关系数矩阵配合模型的特点。

Along with increase of product amount, shortage cost, holding cost, demand variance, and with negative demand covariance, it is more and more profitable from commonality. Further more, holding cost of unit period is the most critical factor to commonality.

但是，随着产品数量的增加，缺货成本的增加，需求变化系数的增加，需求相关系数为负，库存维持费用率的增加，通用件带来的好处越来越明显，对价格的要求也越来越松弛。

Objective To investigate the effects of interleukin-1 β converting enzyme gene on the biologic characteristics of ovarian cancer cells.

目的 探讨白细胞介素-1 β转换酶的表达，对卵巢癌细胞生物学特性的影响。

Campylobacter: This illness is the most commonly identified cause of diarrheal illness in the world.

弯曲：这种病是最常见的原因查明腹泻病，在世界上。