估计

The performance of EFT is investigated, which indicates that time-frequency distributions using single-sided window could not accurately trace the variation of the instantaneous frequency, since their performance depend only on the history of the signal, so they are biased frequency estimator.

提出了基于对称阵元互Wigner分布平均的瞬时频率估计算法，这种方法利用多通道数据对时频分布的瞬时频率估计方法的性能进行了有效的改善，并且能够在低信噪比的条件下获得良好的估计效果， 6。

On the basis of diagnosis and measure of multicollinearity,a new biased estimator of unknown parameters called partial ridgeestimator is proposed for Gauss-Markov model.Its properties are discussed,and some important conclusions are drawn.The determination of biased parameter in the PR estimator is discussed too.

基于复共线性诊断和度量的结果，提出了测量平差Gauss-Markov模型参数的一个新的有偏估计，称为基于复共线性诊断和度量的部分岭估计，讨论了部分岭估计的优良性质，提出了岭参数的选取方法。

There are two findings summarized from previous studies:(1) the least squares estimator is a common choice of researchers, but under an unequal probability design, the estimator is biased,(2) the probability weighted estimator is consistent but may have a large variance.

过去的研究发现：(1)在不等机率抽样时，一般常用的最小平方法所得到的回归参数估计式并非不偏估计式；(2)机率加权最小平方法可以改善不偏性，然却增加估计的变异程度。

Based on the invariance of maximum likelihood estimation, the sufficient and necessary condition under which the maximum likelihood estimation has invariance for the parameters are given, then it uses this conclusion to calculate the maximum likelihood estimation of σ^2 and ρ for bivariate normal distribution.

根据参数极大似然估计不变性原则，给出在一定条件下极大似然估计具有不变性的充分必要条件，并利用该结论计算了二元正态分布Z=的未知参数σ^2和ρ的极大似然估计值。

Therefore, the SR-MUSIC suffers no DOA estimation errors from the estimates of thenoise characteristic exponent and the selections of the FLOM parameters.

该算法不需要FLOM参数p的选择，从而避免了基于阵列共变矩阵和阵列FLOM矩阵的DOA估计方法由于需要噪声特征指数的估计和由于不同参数p所带来的DOA估计误差。

The core of this paper is to analyze and probe into ridge regression from different ideas, such as the existence of ridge parameter K, the choiceness of ridge estimation K , the choice of ridge parameter K and the methods of regression coefficients.

本文简单介绍了主成分回归，阐述了主成分估计方法的原理和优缺点；重点是从不同的角度不同的思想出发，对最常见的岭回归估计法进行了深入的探讨：岭参数K 的存在性，岭估计的优良性，岭参数K 的选择方法等。

Therefore, the time delay estimation of a signal can be obtained based on the correlative principle of periodic series -- circular correlation.

在时延估计的广义相关法中[1 10]，滤波后的传感器输出是互相关的，并将互相关估计取峰值时的滞后取作时延的估计。

A new frequency estimation algorithm for Time Domain Synchronization OEDM system is proposed, which utilizes the time domain circular characteristic of PN sequences to adjust frequency offset and then uses a variable step frequency scan scheme to estimate large frequency offset.

提出一种新的适用于TDS-OFDM系统的频偏估计算法，利用PN序列的时域循环特性进行预频偏调整，然后用变步长扫频进行大频偏的估计，定时同步之后再利用PN的时域循环特性进行细偏估计。

The Minimax admissibility of linear estimates with respect to restricted multivariate regression coefficient under matrix loss function is considered.

在矩阵损失下给出了带约束的多元回归系数线性估计在线性估计类中是 Minimax可容许估计的充要条件。

Recently many of statisticians have been interested in the functional coefficient model because of its simplifying structure, meaningful interpretation and wide application. In the chapter 2, estimators of parameters of linear functional coefficient structural model under interval-censored covariate studied.

由于协变量区间删失，为此我们创立了一个与协变量具有相同均值的变量，然后利用加权最小二乘估计法得到了变系数一维线性结构关系模型中的参数估计，当协变量的分布已知时，证明了估计的弱相合性和强相合性。

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。