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21.
The mean density of bacteria in a water body is commonly monitored using quantal assay. This paper describes the use of local scoring in estimating the spatial distribution of mean density from quantal assay results at a set of point locations. An application to estimating the mean density of fecal conform bacteria in a coastal pond is presented. Model diagnostics based on a parametric bootstrap are also presented. 相似文献
22.
叶露 《华中师范大学研究生学报》2006,(2)
近年来《红楼梦》英译研究发展迅速,许多学者都从不同领域对其进行研究。但将功能语篇分析理论应用到《红楼梦》及其英译文的对比研究,国内外尚不多见。本文将以韩礼德系统功能语言学作为理论基础,从语篇分析的角度,以《红楼梦》原著及其杨宪益夫妇的英译本为语料,重点讨论《红楼梦》作为章回小说,其语篇体裁标记语在英译文中如何处理的。 相似文献
23.
Abstract: The subject of this paper is to describe the complexity of relations between man and wild monkeys, which causes difficulties in forming a social consensus related to their conservation and management. To present how the relations are in everyday life, and how they are simplified in universal discursive spaces, interviews and a questionnaire survey have been conducted. As a result, it is clarified that there are three kinds of discursive spaces, that of politics, natural science, and residents. People who share the land with wild monkeys have various terms and stories about their relations with monkeys. The monkeys have various values in the discourse of residents, including many troubles. The existence of monkeys is vivid and close, and can be described as "accessible" nature. However, in discussion of politics or natural sciences, there is less diversity in monkeys' values. In these discursive spaces, monkeys are described simply in the framework of "distant" nature, and wild monkey issues are constructed as a "pest animal issue". The simplified protocol between accessible and distant nature makes the wild monkey issues simple. And the attitudes of residents are shown as controversial through the contradiction between simple-complex issues. In conclusion, this contradiction cannot be solved only by filling the gap between accessible and distant nature with social consensus, but also by connecting the two and enhancing the dynamism of society as a whole. 相似文献
24.
Standard algorithms for the construction of iterated bootstrap confidence intervals are computationally very demanding, requiring nested levels of bootstrap resampling. We propose an alternative approach to constructing double bootstrap confidence intervals that involves replacing the inner level of resampling by an analytical approximation. This approximation is based on saddlepoint methods and a tail probability approximation of DiCiccio and Martin (1991). Our technique significantly reduces the computational expense of iterated bootstrap calculations. A formal algorithm for the construction of our approximate iterated bootstrap confidence intervals is presented, and some crucial practical issues arising in its implementation are discussed. Our procedure is illustrated in the case of constructing confidence intervals for ratios of means using both real and simulated data. We repeat an experiment of Schenker (1985) involving the construction of bootstrap confidence intervals for a variance and demonstrate that our technique makes feasible the construction of accurate bootstrap confidence intervals in that context. Finally, we investigate the use of our technique in a more complex setting, that of constructing confidence intervals for a correlation coefficient. 相似文献
25.
Abstract. The likelihood ratio statistic for testing pointwise hypotheses about the survival time distribution in the current status model can be inverted to yield confidence intervals (CIs). One advantage of this procedure is that CIs can be formed without estimating the unknown parameters that figure in the asymptotic distribution of the maximum likelihood estimator (MLE) of the distribution function. We discuss the likelihood ratio-based CIs for the distribution function and the quantile function and compare these intervals to several different intervals based on the MLE. The quantiles of the limiting distribution of the MLE are estimated using various methods including parametric fitting, kernel smoothing and subsampling techniques. Comparisons are carried out both for simulated data and on a data set involving time to immunization against rubella. The comparisons indicate that the likelihood ratio-based intervals are preferable from several perspectives. 相似文献
26.
昆嵛山野生经济植物及开发利用 总被引:1,自引:0,他引:1
报道了昆嵛山野生经济植物681种及变种,隶属101科,552属.根据其经济用途分为七大类,并提出了开发利用意见. 相似文献
27.
通过分析我国西部流域开发中的不同争论,强调河流的审美功能也同样值得关注。在对美国《自然与风景河流法案》进行分析的基础上,认为有必要进一步促进公众的参与,通过加强流域总体规划,构建具有中国特色的风景河流保护体系,并形成统一的中国国家公园管理体系,这将有力促进西部可持续发展。 相似文献
28.
Stephan Smeekes 《Econometric Reviews》2019,38(9):1089-1107
This article develops two block bootstrap-based panel predictability test procedures that are valid under very general conditions. Some of the allowable features include cross-sectional dependence, heterogeneous predictive slopes, persistent predictors, and complex error dynamics, including cross-unit endogeneity. While the first test procedure tests if there is any predictability at all, the second procedure determines the units for which predictability holds in case of a rejection by the first. A weak unit root framework is adopted to allow persistent predictors, and a novel theory is developed to establish asymptotic validity of the proposed bootstrap. Simulations are used to evaluate the performance of our tests in small samples, and their implementation is illustrated through an empirical application to stock returns. 相似文献
29.
《Journal of Statistical Computation and Simulation》2012,82(5):671-679
This paper provides a saddlepoint approximation to the distribution of the sample version of Kendall's τ, which is a measure of association between two samples. The saddlepoint approximation is compared with the Edgeworth and the normal approximations, and with the bootstrap resampling distribution. A numerical study shows that with small sample sizes the saddlepoint approximation outperforms both the normal and the Edgeworth approximations. This paper gives also an analytical comparison between approximated and exact cumulants of the sample Kendall's τ when the two samples are independent. 相似文献
30.
《Journal of Statistical Computation and Simulation》2012,82(11):1077-1085
Recently, many standard families of distributions have been generalized by exponentiating their cumulative distribution function (CDF). In this paper, test statistics are constructed based on CDF–transformed observations and the corresponding moments of arbitrary positive order. Simulation results for generalized exponential distributions show that the proposed test compares well with standard methods based on the empirical distribution function. 相似文献