共查询到19条相似文献，搜索用时 109 毫秒
1.
电子元器件可靠性寿命分析中,右截尾类型的数据居多,针对此类数据的分析方法也很多。其中,线性回归和极大似然估计应用较广。在此,运用实例对这两种方法进行了对比分析,指出了使用线性回归法进行参数估计的缺点,说明极大似然估计法是比线性回归法更优的统计模型。 相似文献
2.
在多元线性回归模型参数估计中,采用普通最小二乘法,必须在遵循经典的假定的条件之下才具有良好的性质,在违背基本假定的情况下,比如存在异方差和序列相关时,最小二乘法将不再是最佳的线性无偏估计量。而在放宽经典的假设之下,应用极大似然估计法和矩估计法仍然得到了与普通最小二乘法相同的结果。 相似文献
3.
对天然产物中有机硒的分析方法进行了简要论述．研究了用原子荧光法（AFS）测定天然产物酸枣中有机硒的方法，选择了最佳仪器工作条件及化学试剂用量．方法检出限为0．57μg／L，线性范围为0—100μg/L，相关系数r=0．9997，回收率为91．75％～110．50％，变异系数小于2.024％． 相似文献
4.
在社会科学的量化研究中,如何处理缺失数据,一直是困扰研究者的问题。传统上研究者们多采用直接删除、配对删除等方法,但这些方法都存在难以克服的缺陷。当今欧美大多数学者处理缺失数据时都采用最大拟然估计法和多重归因法,且实践已经证明了这两种方法的优越性。本文简单总结了传统的缺失数据处理方法,并对最大拟然估计法和多重归因法进行评介,以期提高量化研究中缺失数据处理的技术。 相似文献
5.
高友福 《长江工程职业技术学院学报》2006,23(4):54-57
介绍语音信号的线性预测分析原理,并详细分析用来求解线性预测正则方程的自相关法、Burg法、协方差法的原理和计算方法,并对算法进行了比较. 相似文献
6.
用几种不同的密度推定法,对测线调查样本进行密度推定。使用的最佳带幅宽有的依赖于探知函数,有的不依赖探知函数,还用到经典的最大似然估计法。把5种密度推定法用于计算机模拟产生测线调查的距离数据,由统计量RRMSE和RB对推定值进行评价,来验证其优劣。 相似文献
7.
叶华山 《延安教育学院学报》2012,26(4):82-83,86
简要论述物理实验中数据处理的几种常用方法,分别对列表法、作图法、图解法、差分法和最小二乘法等对物理实验数据处理方法进行探讨,并对这几种方法的优缺点进行比较,重点论述了逐差法和最小二乘法（线性拟合）的原理,提出了如何根据实验目的正确地选择和使用物理实验数据处理的方法。 相似文献
8.
利用小样本数据预处理技术提高效能指标精度 总被引：1，自引：0，他引：1
提出了运用熵值判别法和线性均方估计法来处理小样本数据的方法.熵值判别法是根据熵的上界对应最大的不确定度,利用所得数据的熵信息量判别数据是否含有粗大误差;线性均方估计消除粗大误差是一种采用软化的方法处理粗大误差.经过多次试验,结果表明这两种方法在处理小样本采样数据时能够有效地提高数据精度. 相似文献
9.
王春草 《杨凌职业技术学院学报》2007,6(4):43-44
常数变易法是求解微分方程的一种很重要的方法，常应用于一阶线性微分方程的求解。本文通过对几种微分方程研究分析，总结了常数变易法在求解线性微分方程中的几点新的应用。 相似文献
10.
《现代教育技术》2019,(5):92-98
文章对计算机自适应测试中常用的参数估计法——联合极大似然估计(Joint Maximum Likelihood Estimation,JMLE)法进行了改进,提出了一种基于三值矩阵的联合参数估计方法——3V-JMLE法。基于此,文章以作答反应数据库中被试作答信息为样本,分别采用JMLE法、3V-JMLE法进行参数估计,其对比结果表明:在理想作答矩阵下,3V-JMLE法和JMLE法具有同等的参数估计精度和计算效率;在非理想作答矩阵下,采用JMLE法进行参数估计存在一定的局限性,而采用3V-JMLE法具有很高的参数估计精度并大大提高了计算效率。3V-JMLE法的提出,对于联合参数估计方法的实际估计参数过程有重要指导意义。 相似文献
11.
一般广义岭估计的效率上界 总被引：2，自引：0，他引：2
考察一般Gauss-Markov模型中未知参数向量的最优线性无偏估计的改造问题,讨论了方兴等人提出的最优化无偏估计的一种估计的相对效率,把该文中给出的一般岭估计的相对效率的上界,推广到一般广义岭估计的相对效率的上界.yh 相似文献
12.
对于农业研究中多变量线性模型参数的估计,以往常采用经典统计方法。随着计算机技术的进步,贝叶斯统计方法在科学研究的各个领域迅速发展。文章利用贝叶斯统计方法对农业研究中的多变量模型进行参数估计,并与经典统计方法进行比较,验证了贝叶斯方法的有效性。该方法可为农业研究中多变量模型参数的估计提供新的途径和手段。 相似文献
13.
Michael J. Kolen 《Journal of Educational Measurement》1991,28(3):257-282
Frequency distributions of test scores may appear irregular and, as estimates of a population distribution, contain a substantial amount of sampling error. Techniques for smoothing score distributions are available that have the capacity to improve estimation. In this article, estimation/smoothing methods that are flexible enough to fit a wide variety of test score distributions are reviewed. The methods are a kernel method, a strong true–score model–based method, and a method that uses polynomial log–linear models. The use of these methods is then reviewed, and applications of the methods are presented that include describing and comparing test score distributions, estimating norms, and estimating equipercentile equivalents in test score equating. Suggestions for further research are also provided. 相似文献
14.
A new relative efficiency of parameter estimation for generalized Gauss-Markov linear model was proposed. Its lower bound was also derived. Its properties were explored in comparison with three currently very popular relative efficiencies. The new relative efficiency not only reflects sensitively the error and loss caused by the substitution of the least square estimator for the best linear unbiased estimator, but also overcomes the disadvantage of weak dependence on the design matrix. 相似文献
15.
Zhu Jun 《浙江大学学报(A卷英文版)》2000,1(1):78-90
New approaches based on general mixed linear models were presented for analyzing complex quantitative traits in animal models,
seed models and QTL (quantitative trait locus) mapping models. Variances and covariances can be appropriately estimated by
MINQUE (minimum norm quadratic unbiased estimation) approaches. Random genetic effects can be predicted without bias by LUP
(linear unbiased prediction) or AUP (adjusted unbiased prediction) methods. Mixed-model based composite interval mapping (MCIM)
methods are suitable for efficiently searching QTLs along the whole genome. Bayesian methods and Markov Chain Monte Carlo
(MCMC) methods can be applied in analyzing parameters of random effects as well as their variances.
Projects supported by NSFC (39670390, 39893350) and the NIH Grant GM32518 相似文献
16.
17.
Simulations of computerized adaptive tests (CATs) were used to evaluate results yielded by four commonly used ability estimation methods: maximum likelihood estimation (MLE) and three Bayesian approaches—Owen's method, expected a posteriori (EAP), and maximum a posteriori. In line with the theoretical nature of the ability estimates and previous empirical research, the results showed clear distinctions between MLE and the Bayesian methods, with MLE yielding lower bias, higher standard errors, higher root mean square errors, lower fidelity, and lower administrative efficiency. Standard errors for MLE based on test information underestimated actual standard errors, whereas standard errors for the Bayesian methods based on posterior distribution standard deviations accurately estimated actual standard errors. Among the Bayesian methods, Owen's provided the worst overall results, and EAP provided the best. Using a variable starting rule in which examinees were initially classified into three broad/ability groups greatly reduced the bias for the Bayesian methods, but had little effect on the results for MLE. On the basis of these results, guidelines are offered for selecting appropriate CAT ability estimation methods in different decision contexts. 相似文献
18.
Benjamin D. Wright 《Structural equation modeling》2013,20(1):3-24
This article illustrates how Rasch measurement is preferable to factor analysis for reducing complex data matrices to unidimensional variables. The two methods: (a) address the same kind of data, but with different interpretations of numerical status; (b) use the same estimation methods, but with different measurement models; and (c) solve the same problems, but with substantially different utility. Factor analysis is faulted for mistaking ordinally labeled stochastic observations for linear measures and for failing to construct linear measurement. The motivation and mathematical basis for Rasch measurement are introduced. How to use Rasch measurement to replace factor analysis is developed for a dichotomy and demonstrated for a rating scale. 相似文献
19.
MIXED LINEAR MODEL APPROACHES FOR ANALYZING GENETIC MODELS OF COMPLEX QUANTITATIVE TRAITS 总被引：2，自引：0，他引：2
ＩＮＴＲＯＤＵＣＴＩＯＮＭａｎｙｇｅｎｅｔｉｃｍｏｄｅｌｓｂａｓｅｄｏｎｔｈｅａｐｐｒｏａｃｈｏｆＡＮＯＶＡ (ａｎａｌｙｓｉｓｏｆｖａｒｉａｎｃｅ)ｗｅｒｅｄｅｖｅｌ ｏｐｅｄｂｙＦｉｓｈｅｒ(1 92 5) .Ｓｏｍｅｏｆｔｈｅｓｅｍｏｄｅｌｓ,ｅ.ｇ .ＮＣｄｅｓｉｇｎＩａｎｄＩＩ(Ｃｏｍｓｔｏｃｋｅｔａｌ.,1 952 ;Ｈａｌｌａｕｅｒｅｔａｌ.,1 981 ) ,ｄｉａｌｌｅｌｍｏｄｅｌｓ(Ｙａｔｅｓ,1 94 7;Ｇｒｉｆｆｉｎｇ,1 956;ＧａｒｄｎｅｒａｎｄＥ ｂｅｒｈａｒｔ,1 966) ,ａｒｅｓｔｉｌｌｗｉｄｅｌｙｕｓｅｄｂｙｐｌａ… 相似文献