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Estimation of the parameter in the problem of the Nile is treated as a decision problem with squared error loss, It is shown that the minimum risk scale equivariant estimator dominates the incomplete sufficient unbiased estimators considered by Iwase and Seto, Sharper bounds for the equivariant estimator are derived which may be used to obtain the values of the same from the sample with sufficient accuracy.  相似文献   

3.
The joint efforts in the USSR by the Central Planning Commission and the State Statistical Commission to develop projections of family characteristics of the Soviet population are described. The projections, based on official data for the rural and urban populations in 1987, are for the years 1991, 1996, 2001, and 2006.  相似文献   

4.
The usual maximum likelihood estimators of the parameters of the von Mises distribution are shown to perform badly in small samples. In view of this and the fact that these estimators require a large amount of computation, alternative, simpler estimators are proposed. It is shown that these estimators are at least comparable to the traditional estimators and are, in many cases, superior to them. We also apply the procedure of jackknifing to the maximum likelihood estimator of the concentration parameter of the von Mises distribution and compare the properties of the jackknifed estimator with the other estimators considered in this paper.  相似文献   

5.
Abstract

We discuss the accuracy of the computation and present a fortran program to compute the cumulative distribution function (CDF) for the analysis of means (ANOM).  相似文献   

6.
This paper contains a study of the qualitative properties of the maximum likelihood estimate of the scale parameter of the Student family as a function of its (continuous) degrees of freedom. Sharp bounds are provided for the estimate and its (continuous) degrees of freedom. Sharp bounds are provided for the estimate and its monotonicity as a function of the degrees of freedom is established. Inferential implications are also discussed.  相似文献   

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人工神经网络变量选取与隐藏单元数的确定   总被引:2,自引:0,他引:2  
根据多隐藏层所有训练样本误差平方和最小设计优化问题,求解并绘出计算流程图。Trevor等人认为隐藏单元过多比过少好,交叉验证估计(隐藏单元)正则化参数没有必要。还有一种通常做法是常常利用分类树挑选变量作为输入变量进行人工神经网络建模。而从人工神经网络与多元统计、传统回归和其他数据挖掘工具的区别和联系出发,认为这些观点和做法值得商酌;用ZIP编码实例说明隐藏单元过多不一定比过少好,实际数据分析中所需隐藏单元数的确定可以用交叉验证结合经验判断来实现,利用分类树选择的变量对于人工神经网络没有太大的效果;通过分类树删节变量以降低计算量的效果不如通过压缩隐藏单元个数降低计算量来得好;非完全问题“从简单到一般”思想与完全问题中选择所有变量的思想不矛盾。在总结了Le Cun等人的局部联结以有效降低权数思想的基础上,提出通过随机选择人工变量建立人工神经网络分布式模型系统的设想。  相似文献   

9.
The USSR is moving from extensive to intensive type of population reproduction, not because of any governmental measures but as a reaction to objective circumstances. At present there is a reduction in the population cohort of working age. This has an adverse effect on production. And the number of the elderly is increasing; we must involve them more in the production process, in monitoring the service sphere, for instance. The infant mortality rate has declined sharply in the USSR, especially since World War II. The birthrate has also dropped, but it is still higher than in the US, France, or West Germany. Some authorities think that this (the ZPG) is a good idea, but this author thinks it is a bad idea, meaning a drop in society's productive forces. We need an active demographic policy, meaning one which ensures optimal reproduction of the population with an improvement in its health, culture, and living standard. The policy must be differentiated, as conditions vary from one part of the country to another. An example is the 1981 decree on assistance to families with children which provides for payments of 35-50 rubles/month to mothers who must stay home to look after children. The number of children per family to ensure reproduction must be 2.6 on the average. In the Central Asian republics family sizes of 4-5 children are anticipated, but in the RSFSR, Ukraine, Belorussia, and the Baltic republics the anticipated size of families is rather low. Measures must be taken to alter this by providing assistance to families with children.  相似文献   

10.
The X2 approximation to the distribution of the sample coefficient of variation of a normally distributed random variable, due to McKay 1932 is not nearly as accurate as suggested by the confirmatory studies of Fieller 1932 and Pearson 1932.The approximation will, however, be adequate in many practical situations and has the convenience of requiring nothing more than the readily available tables of x2.  相似文献   

11.
影响统计数据质量的因素是多方面的。提高统计数据质量不仅要改进统计的方法技术,还需要建设优良的统计社会环境,为统计提供良好的条件,所以应当重视“统计生态环境建设”的问题。“统计生态环境建设”包括有利于确保数据质量的思想观念环境、政府统计的体制环境、包含数据真实性的社会信用体系以及保障统计数据质量的法制环境。  相似文献   

12.
The systematic error (bias) of the isotonic regression analysis of temporal spacings between failure events is investigated by means of numerical simulation. Spacings that are sampled from an exponential distribution with a constant failure rate (CFR) arc subjected to an isotonic regression search for a declining failure rate (DFR). The results indicate a considerable declining trend (bias) that is imposed upon these CFR-data by isotonic regression analysis. The corresponding results for an increasing trend can be readily obtained through transformation. For practical applications, the results of 100,000 simulations have been approximated by simple analytical expressions. For the evaluation of a trend in a specific set of isotonized spacings (or rates) the results of the latter analysis can be compared with the isotonic bias of a set of CFR data for the same number of events. Alternatively, the specific set of isotonized spacings can be suitably related to the corresponding isotonized CFR data to reduce the bias by largely eliminating the CFR contribution.  相似文献   

13.
Intervention-ARIMA模型在我国第三产业就业人数预测中的应用   总被引:4,自引:0,他引:4  
万平 《统计教育》2009,(9):31-33,37
本文利用Intervention—ARIMA模型对我国第三产业就业人数(1952—2006年)时间序列进行了动态拟合,重点考虑了“大跃进”对我国第三产业就业人数的干预影响,取得了很好的拟合效果,并预测了我国未来几年第三产业就业人数的发展趋势。证明了第三产业发展对缓解我国当前就业压力的积极效应。  相似文献   

14.
Two methods of estimation for the parameters of an AR(1) process which are based on a non-linear least-squares approach are presented. On the basis of some simulation results they are compared with two maximum likelihood estimates and their relative merits are discussed.  相似文献   

15.
白仲林等 《统计研究》2019,36(11):37-48
本文依据2014年10月至2017年11月16个“非同期”限购城市和29个非限购城市的面板数据,利用广义合成控制法研究了房地产市场限购政策调控商品房价格、促进实体经济发展的政策效应。研究发现:限购政策能够有效地抑制商品房价格过快上涨,政策效应因商品房建筑面积和城市规模等特征存在差异性;同时发现了房地产限购政策与实体经济发展相关联的典型事实,并证实了限购政策对支持实体经济发展存在较显著的“回馈效应”,特别是由限购政策产生的转移投资对实体经济产出存在约10个月的滞后期。  相似文献   

16.
The usual F-test of the analysis of variance is reconsidered within the Bayesian framework, In terms of predictive distributions, This leads to the notion of semi-Bayesian significance test, so called because it consists in only probabilizing the space of nuisance parameters, thus bringing a general principle for “eliminating” nuisance parameters, or more exactly incorporating information about these parameters. The approach is shown to extend the F-tests, by allowing the testing of hypotheses of non-zero effects.  相似文献   

17.
建立科技社团公信力指标体系,需要澄清几个方面的问题:包括科技社团、科技社团的特点、公信力的界定等,而这些问题的讨论旨在通过将定性指标和定量指标有机地结合起来,以建立科技社团公信力指标体系。  相似文献   

18.
The robustness of the power function of the standard one-sample parametric test for the mean of the negative exponential distribution is examined. The main form of departure from the exponential assumption is a mixture of negative exponential components although an alternative Gamma distribution is also examined. It is found that the test is sensitive to these departures although the effect of mixtures with short tails is less dramatic than those with long tails.  相似文献   

19.
Nonnegative estimators for the variance components of a linear model are obtained by ignoring the condition for unbiasedness in the principle of the MINQUE. An estimator is derived when the priori weights are proportional to the variance components. The ordinary sample variance is shown to be the nonnegative MINQUE. Efficiencies of the three estimators are examined for some special cases of the model.  相似文献   

20.
It is proved that the accuracy of the bootstrap approximation of the joint distribution of sample quantiles lies between O(n?1/4) and O(n?1/4 an), where (log(n))1/2=O(an). As an application, we investigated confidence intervals based on the bootstrap.  相似文献   

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