参数估计

For fitting ROC curves and getting the area under the ROC curve, we applied the parametric methods of binormal models and ordinal regression models, the semiparametric method of Cox proportional hazards model, the nonparametric methods of Hanley, Delong.

本文采用双正态模型、有序回归模型等参数法，Cox比例风险模型半参数法，Hanley、Delong非参数法拟合了ROC曲线；文中也考虑了样本量的估计、协变量的混杂效应、再抽样技术计算ROC曲线下面积的标准误与可信区间等问题；并研究了SROC分析方法。

How to quantitatively determinate the relation between system behaviors and parameters variations was an important problem of systems biology.In order to study robustness of NF-κB signal transduction networks,the parameters of system model were assigned to subject to stochastic distributions.

然而，包括速率常数和反应物初始浓度在内的许多参数都是通过实验测量或者根据文献推断得到的，即使对于那些完全通过实验来估计参数的模型，也不能确定参数的实际值与对应的生物系统是否完全一致。

Finally, to explain the advantage and shortcoming of nonparametric analysis and parametric analysis, and introduce some main shapes of nonpametric regression model: Fourier series, kernel estimators, and spline smoothing. In the meantime, we give the approximate theory and approximate distribution theory of these methods.

阐述了非参数回归分析和参数回归分析的优缺点，介绍了非参数回归模型的几种主要形式：富氏级数，核估计量和样条平滑，给出了这些方法的逼近理论和逼近分布情况。

To power grid parameter and topology error which are two main factors for the compute result of power system analysis software , research and develop the parameter identification and topology error identification system of power grid.

针对电网参数和网络拓扑影响电力系统高级应用软件计算结果的两个主要因素，以开关有功潮流估计算法和多断面参数辨识算法为核心，研究开发了电网参数辨识与实时拓扑检错系统，并在福州电网得到了应用。

In order to reduce calculation error, the frequency distribution of average values is used to compute the mixed distribution's digital features of each component distribution, thereinto, the number of the component distribution is determined by AIC, choose the number that meets the minimum value of AIC as the component number of mixed distribution, and the other parameters are estimated by EM algorithm; Secondly, because each component distribution is corresponding to a kind of major gene genotype, according to the values of the average and variance of the each component distribution, we can use the limit error of the normal distribution to plot each individual into the correspondent component distribution, namely into correspondent major gene genotype. Then we regard each major gene genotype as a treatment level of one-way analysis of variances, and the one-way multivariate analysis of variance is carried out to calculate the covariance matrix of major gene effect, covariance matrix of polygene effect, covariance matrix of environment effect and so on; At last, combining the weights of the each component distribution of mixed distribution, we can calculate the variance of major gene effect, the variance of polygene effect, environmental variance and the genetic gain of the quantitative trait.

为减小计算误差，本研究采用均值的频数分布来计算各成分分布的数字特征，其中成分分布个数根据AIC准则，选择使AIC值达到最小的成分分布个数作为混合分布的成分分布数，分布中其它参数的确定利用EM算法来估计；其次，每个成分分布对应一种主基因基因型，根据各个成分分布的均值和方差，利用正态分布的极限误差将每个个体划分到相应的成分分布中，即相应的主基因基因型中，将每种主基因型作为单因素方差分析的一个处理水平，对其进行单因素的多元方差分析，分别计算主基因效应协方差阵、多基因效应协方差阵、环境协方差阵等参数；最后结合混合分布中各成分分布的权重即各主基因基因型的分离比例，计算主基因效应方差，多基因效应方差和环境方差，以及遗传力等参数，进而计算该数量性状的遗传进展。

An optimization procedure is established to obtain location parameter of Weibull distribution, which corresponds to the maximum of the absolute value of the linear regression coefficient.

通过对线性拟合相关系数的最优化求解来确定Weibul分布的位置参数，再由最小二乘拟合便可估计出Weibul分布的形状参数和尺度参数。

This paper adopts parametric method, semiparametric method and nonparametric method to estimate the VaR of the futures market.

本文分别采用参数法、半参数法与非参数法来估计铜期货市场的风险值。

Introduced a different strategy for estimating the working correlation so that the estimator always existed, and, even if the correlation was misspecified, the regression estimator remained optimal within the assumed family.

这一思想的好处是不用直接估计工作相关阵中的多余参数，而是利用广义矩估计的思想建立估计方程。

During the process of state estimation, recursive extended least square was introduced to update the parameters of state model, at the same time exponential weighted algorithm was put in use to estimate the statistical characteristic of time-varying noise.

这样，在利用量测数据进行状态估计的同时，来不断的对系统模型参数和噪声统计特性进行估计和修正以提高模型精确度，降低状态估计的误差。

Judgement and Solution Methods of UMVUE ;2. The maximum likelihood estimate and uniformly minimal variance unbiased estimate of MTTF were made on the one-unit system whose lifetime was assumed to be on GAMMA distribution.

讨论寿命服从单参数GAMMA分布单元平均寿命的极大似然估计和一致最小方差无偏估计；应用BASU定理求出了单元可靠度及串联系统可靠度的一致最小方差无偏估计。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新