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31.
W. Stute 《Journal of statistical planning and inference》1992,30(3):293-305
We propose a new modified (biased) cross-validation method for adaptively determining the bandwidth in a nonparametric density estimation setup. It is shown that the method provides consistent minimizers. Some simulation results are reported on which compare the small sample behavior of the new and the classical cross-validation selectors. 相似文献
32.
33.
统计调查课程的现状与调整思路 总被引:1,自引:0,他引:1
文章从统计调查课程设置的现状出发,介绍了当前随着社会经济的发展和统计调查方法体系的改革,统计调查理论体系以及统计调查课程设置的不足,叙述了统计调查课程调整的思路。要实施这个思路,必须重视统计调查对象内容的变化,并注重借鉴国外成熟的经验。为适应形势的发展,随着现行统计调查方法体系的调整与完善,对统计调查课程也要作相应的调整。 相似文献
34.
35.
Peter J. Robinson 《Risk analysis》1992,12(1):139-148
Because of the inherent complexity of biological systems, there is often a choice between a number of apparently equally applicable physiologically based models to describe uptake and metabolism processes in toxicology or risk assessment. These models may fit the particular data sets of interest equally well, but may give quite different parameter estimates or predictions under different (extrapolated) conditions. Such competing models can be discriminated by a number of methods, including potential refutation by means of strategic experiments, and their ability to suitably incorporate all relevant physiological processes. For illustration, three currently used models for steady-state hepatic elimination--the venous equilibration model, the parallel tube model, and the distributed sinusoidal perfusion model--are reviewed and compared with particular reference to their application in the area of risk assessment. The ability of each of the models to describe and incorporate such physiological processes as protein binding, precursor-metabolite relations and hepatic zones of elimination, capillary recruitment, capillary heterogeneity, and intrahepatic shunting is discussed. Differences between the models in hepatic parameter estimation, extrapolation to different conditions, and interspecies scaling are discussed, and criteria for choosing one model over the others are presented. In this case, the distributed model provides the most general framework for describing physiological processes taking place in the liver, and has so far not been experimentally refuted, as have the other two models. These simpler models may, however, provide useful bounds on parameter estimates and on extrapolations and risk assessments. 相似文献
36.
对偶线性规划问题性质探析 总被引:1,自引:0,他引:1
探讨对偶线性规划的原始问题与对偶问题的属性,阐述两者的区别和内在联系,用较简便的方法论证其重要性质,揭示可行解与目标函数、可行解与最优解的关系,指出线性规划问题最优解从约束条件较少的对偶问题寻求为另一较简便之方法。 相似文献
37.
组合预测误差信息矩阵研究 总被引:11,自引:0,他引:11
唐小我 《电子科技大学学报(社会科学版)》1992,(4)
研究组合预测误差信息矩阵的结构与组合预测方法性质之间的联系,首次提出冗余信息概念,对最优组合预测方法的组合结构进行了研究。 相似文献
38.
The small sample performance of least median of squares, reweighted least squares, least squares, least absolute deviations, and three partially adaptive estimators are compared using Monte Carlo simulations. Two data problems are addressed in the paper: (1) data generated from non-normal error distributions and (2) contaminated data. Breakdown plots are used to investigate the sensitivity of partially adaptive estimators to data contamination relative to RLS. One partially adaptive estimator performs especially well when the errors are skewed, while another partially adaptive estimator and RLS perform particularly well when the errors are extremely leptokur-totic. In comparison with RLS, partially adaptive estimators are only moderately effective in resisting data contamination; however, they outperform least squares and least absolute deviation estimators. 相似文献
39.
The L1 and L2-errors of the histogram estimate of a density f from a sample X1,X2,…,Xn using a cubic partition are shown to be asymptotically normal without any unnecessary conditions imposed on the density f. The asymptotic variances are shown to depend on f only through the corresponding norm of f. From this follows the asymptotic null distribution of a goodness-of-fit test based on the total variation distance, introduced by Györfi and van der Meulen (1991). This note uses the idea of partial inversion for obtaining characteristic functions of conditional distributions, which goes back at least to Bartlett (1938). 相似文献
40.
Gini’s nuclear family 总被引:1,自引:0,他引:1
Rolf Aaberge 《Journal of Economic Inequality》2007,5(3):305-322
The purpose of this paper is to justify the use of the Gini coefficient and two close relatives for summarizing the basic
information of inequality in distributions of income. To this end we employ a specific transformation of the Lorenz curve,
the scaled conditional mean curve, rather than the Lorenz curve as the basic formal representation of inequality in distributions
of income. The scaled conditional mean curve is shown to possess several attractive properties as an alternative interpretation
of the information content of the Lorenz curve and furthermore proves to yield essential information on polarization in the
population. The paper also provides asymptotic distribution results for the empirical scaled conditional mean curve and the
related family of empirical measures of inequality.
相似文献