估计

In conventional indirected parameter estimate, such as Weighted Least Square Method, the changing activity of the injected radiotracer is conventionally measured through multiple consecutive PET image reconstructions. The image of the radioactivity distribution in each frame is reconstructed independently and the whole set of frames is then used to estimate the distribution of the physiological parameter of interest by the application of an appropriate pharmacokinetic model to the time radioactivity curve either of appropriately selected functional regions or of each image element.

传统的间接参数估计方法如加权最小二乘参数估计方法(Weighted Least SquareMethod，WLS)，需要首先从测量数据重建出PET动态放射性活度图像，然后在这些时间上连续的重建图像应用适当的动力学模型上估计感兴趣的生理参数，然而PET重建图像中往往含有极大的噪声，这些噪声将影响参数估计的准确性。

This gives rise to subcarriers phase rotation and InterCarrier Interference, so the orthogonality of subcarriers is destroyed. In this paper, an iterative PHN mitigation method is proposed.

该文提出了一种新的OFDM接收机PHN估计和抑制方法，利用判决数据采用Huber ML估计方法对PHN引起的ICI分量进行迭代估计，将估计的ICI系数变换到时域来校正每个样点的相位误差，从而达到抑制PHN的目的。

First, this paper gives an introduction of some methods of unequal probability sampling, their estimators and variance estimators, including sampling with pps with replacement, methods of sampling without replacement suggested by Brewer, Durbin, Sampford , Des Raj , Murthy , Rao-Hartley-Cochran. Then, at the basis of Rao and Bayless's study , we consider that population can be splited two random subpopulations, which are respectively drawn from different infinite super-populations, and compare the stabilities of estimators of the methods that given above.

本文首先从理论上介绍了若干种不等概率抽样方法，它们的估计量、估计量的方差及其估计，其中包括有放回PPZ及PPS抽样，不放回不等概率抽样中的Brewer、Durbin、Sampford、Des Raj，Murthy、Rao-Hartley-Cochran等人的方法；其次，在Rao和Bayless两人就样本单元数n=2的情形对上述抽样方法进行比较的基础上，将总体随机地分成两个子总体，视每个子总体取自不同的线性超总体，在文中，我们利用计算机实现随机分组，并通过画图比较各方法估计量的稳定性，结果表明，对变异系数C.V。

First, this paper gives an introduction of some methods of unequal probability sampling, their estimators and variance estimators, including sampling with pps with replacement, methods of sampling without replacement suggested by Brewer, Durbin, Sampford , Des Raj , Murthy , Rao-Hartley-Cochran.Then, at the basis of Rao and Baylesss study , we consider that population can be splited two random subpopulations, which are respectively drawn from different infinite super-populations, and compare the stabilities of estimators of the methods that given above.

本文首先从理论上介绍了若干种不等概率抽样方法，它们的估计量、估计量的方差及其估计，其中包括有放回PPZ及PPS抽样，不放回不等概率抽样中的Brewer、Durbin、Sampford、Des Raj，Murthy、Rao-Hartley-Cochran等人的方法；其次，在Rao和Bayless两人就样本单元数n=2的情形对上述抽样方法进行比较的基础上，将总体随机地分成两个子总体，视每个子总体取自不同的线性超总体，在文中，我们利用计算机实现随机分组，并通过画图比较各方法估计量的稳定性，结果表明，对变异系数C.V。

First make the subjects give either right or wrong responses to the same question with different b value. When estimating the abilities of the subjects with the use of one-parameter or two-parameter Logistic model, it is found that there exists two kinds of unfits.(2) Estimate the abilities of the subjects after introducing c parameter on the basis of the two-parameter model. The first unfit can be rectified. However, the second unfit still exists and the third unfit appears.(3) Then estimate again after introducing y parameter. It is discovered that the second unfit is rectified, but the first unfit still exists and the fourth unfit appears.(4) Form Logistic four-parameter model by introducing c parameter and y parameter at the same time and estimate one more time. This model makes all kinds of unfits, including the first, second, third and fourth unfits, rectified.

1设计这批被试分别做对或做错一道b值不同的试题，用Logistic单、双参数模型对被试进行能力估计时，发现被试能力估计存在着两类失拟现象；(2)在双参数模型基础上增加c参数，对被试进行能力估计，发现c参数能有效纠正第一失拟现象，然而仍然存在第二失拟现象，同时还存在第三失拟现象；(3)在双参数模型基础上增加γ参数，再对被试进行能力估计，发现γ参数能有效纠正第二失拟现象，而仍然存在第一失拟现象，同时还存在第四失拟现象；(4)同时增加c、γ参数形成Logistic四参数模型，再对被试进行能力估计，这时该模型对各类失拟现象，包括第一、第二、第三、第四失拟现象都具有良好拟合能力。

Based on the estimation of the directions of arrival and the Doppler frequencies of the sources, a quaternion model was proposed, which made the estimation of the DOA and the Doppler frequencies similar to that of one-dimensional azimuths so as to avoid direct and indirect pairing with the complex model.

针对阵列信号处理中方向角、多普勒频率的同时估计问题，提出了方向角、多普勒频率的四元数模型，使估计方向角、多普勒频率二维问题与估计一维问题相类似，从而避免了在经典的二维复数模型估计中直接或间接的配对。

The paper discusses moment estimation of parameters on Copulas with two kind of methods-moment estimation and approximate moment estimation, and compares two methods by simulation.

本文研究了Gumbel Copula函数的参数佑计，提出了矩估计和近似矩估计两种方法，分别得到了未知参数的估计结果，并通过模拟研究对这两种方法进行了比较，结果显示矩估计方法更为合理。

In order to overcome the limitations of kernel estimation and shortcomings of the method for determining inliers/outliers threshold in ErrorInVariables model, the projection based Mestimators was improved. First, a new mode search method named adaptive kernel density estimation was proposed. Then, a different strategy was given to determine the inliers.

针对EIV模型中基于投影的M估计方法存在的核密度估计和正常点与异常点阈值确定的局限性，提出一种改进的投影M估计算法：首先给出新的用于搜索极值点的自适应核密度估计函数，然后改进了正常点的确定方法。

In this paper, two-stage Generalized Linear models are developed to estimate the outstanding claims reserve in Non-life insurance. The models are based on the PPCI methods, estimating the claim number and payments per claim incurred respectively to obtain the estimate of OCR and prediction error.

本文以非寿险业务未决赔款准备金估计的确定性方法－PPCI法的思想为基础，分两阶段建立广义线性模型，分别对索赔次数和已发生每案赔付额进行估计，进而得到未决赔款准备金的估计值，并对模型的预测误差进行估计。

In addition, because motion vectors must be estimated in the process of region's motion parameters estimation, this paper discussed the theory and general methods of two-dimensional motion estimation and proposes a fast motion estimation algorithm based on the prediction of neighbour block's motion vector.

此外，由于在区域的运动参数估计过程中涉及到对运动矢量的估计，因此本文还讨论了二维运动矢量估计的原理和一般方法，并提出了一种基于邻域子块的运动矢量预测的快速运动估计算法。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。