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71.
For testing the fit of the inverse Gaussian distribution with unknown parameters, the empirical distribution-function statistic A2 is studied. Two procedures are followed in constructing the test statistic; they yield the same asymptotic distribution. In the first procedure the parameters in the distribution function are directly estimated, and in the second the distribution function is estimated by its Rao-Blackwell distribution estimator. A table is given for the asymptotic critical points of A2. These are shown to depend only on the ratio of the unknown parameters. An analysis is provided of the effect of estimating the ratio to enter the table for A2. This analysis enables the proposal of the complete operating procedure, which is sustained by a Monte Carlo study.  相似文献   
72.
本文对R12在水平管内流动沸腾换热特性作了实验研究。实验结果表明,管内流动沸腾换热与单相对流换热一样,存在热进口效应,国外早期的实验数据由于未能考虑热进口效应而偏大。实验结果还表明,水平流动沸腾周向不均匀换热主要受流动结构影响;截面平均换热系数则与质量流速、热流密度、质量干度和蒸发压力密切相关。分析实验数据证实,流动沸腾换热是由气泡产生而引起的流动充分发展核态沸腾和双相对流蒸发两部分组成的。本文的实验数据与国外已有的换热关系式能较好吻合。  相似文献   
73.
We discuss Bayesian analyses of traditional normal-mixture models for classification and discrimination. The development involves application of an iterative resampling approach to Monte Carlo inference, commonly called Gibbs sampling, and demonstrates routine application. We stress the benefits of exact analyses over traditional classification and discrimination techniques, including the ease with which such analyses may be performed in a quite general setting, with possibly several normal-mixture components having different covariance matrices, the computation of exact posterior classification probabilities for observed data and for future cases to be classified, and posterior distributions for these probabilities that allow for assessment of second-level uncertainties in classification.  相似文献   
74.
Nonparametric deconvolution problems require one to recover an unknown density when the data are contaminated with errors. Optimal global rates of convergence are found under the weighted Lp-loss (1 ≤ p ≤ ∞). It appears that the optimal rates of convergence are extremely low for supersmooth error distributions. To resolve this difficulty, we examine how high the noise level can be for deconvolution to be feasible, and for the deconvolution estimate to be as good as the ordinary density estimate. It is shown that if the noise level is not too high, nonparametric Gaussian deconvolution can still be practical. Several simulation studies are also presented.  相似文献   
75.
Summary The number of larvae reaching maturity within the gall ofAdelges japonicus was positively related to gall volume, and the relationship between the number of mature larvae and gall volume did not change with different densities of colonized larvae. The population changes in the bud galls ofA. japonicus were surveyed by collecting the galls, which did not suffer predation or parasitism within the galls, from young artificial plantations ofPicea jezoensis over two years. In the year when the density of colonized larvae was high, they suffered a 42% mortality within the galls, whereas mortality was nearly zero in the low density year. The numbers of larvae per gall were positively correlated with gall volume. The regression lines of the number of colonized larvae on gall volume did not differ significantly in the regression coefficients between the two years, whereas the intercept was significantly higher in the year when the density of colonized larvae was higher. However, different within-gall mortality nullified this difference, and the regression lines of the number of mature larvae on gall volume had no significant difference both in the regression coefficients and the intercepts. This suggests that the number of mature larvae per gall was limited by available resources within the gall which were positively related to gall volume. In 25% of the galls in which mature larvae inhabited, the space within the galls were completely filled by the larvae, indicating that space was one of the limiting resources. Gall volume also affected the number of adults that emerged from the gall and the potential number of their progeny.  相似文献   
76.
The robustness of Mauchly's sphericity test criterion when sampling from a mixture of two multivariate normal distributions is studied. The distribution of the sphericity test criterion when the sample covariance matrix has a non-central Wishart density of rank one is derived in terms of Meijer's G-functions; its distribution under the mixture model is then deduced. The robustness is studied by computing actual significance levels of the test under the mixture model using the critical values under the usual normal model.  相似文献   
77.
本文主要分析了HEIDENHAIN TNC 310数控铣床系统中圆弧铣削指令及螺纹铣削指令,对螺纹铣削功能进行延伸,扩展到圆弧三轴联动,并对螺纹铣削指令格式进行了修改,从而具有圆弧三轴联动铣削功能。  相似文献   
78.
Technology continues to challenge the public relations practitioner to find ways to inform key constituents. The new technology has given rise to the “new journalism” that includes a declining traditional media and exploding internet media filled with websites and bloggers. The question posed by this research asks: Does the public relations practitioner inherit the same protection offered by “qualified privilege” that is most often associated with the traditional “press” or “reporter?” The research lays a foundation with an examination of defamation and the defense of qualified privilege. The research concludes that if information gathered by the public relations practitioner meets the “intent” and “content” tests, the information qualifies as news. Passing the “news” test, the defense of “qualified privilege” also attaches to the public relations practitioner.  相似文献   
79.
白爱平 《唐都学刊》2006,22(3):11-13
贾岛出家及还俗的时间地点问题是贾岛生平仕历研究的一个重要问题。通过对现有史料记载以及贾岛等人诗文的考证分析,可知贾岛贞元九年(793)在北岳恒山出家为僧,时年15岁。后曾住洛阳石楼及嵩山一带。贞元十七年(801)在石楼与韩愈初次相识。元和六年(811)春在洛阳又遇到时任河南县令的韩愈,同年秋跟随韩愈赴长安准备应进士举,但并未马上还俗。冬十一月返回家乡范阳,处理僧俗事务。至迟于次年即元和七年(812)春还俗并参加进士考试,时年34岁。  相似文献   
80.
In many developing regions, women and young girls spend several hours daily in the collection of natural resources. Still the link between these household resource strategies and stakeholder perceptions of development priorities remains unexplored. This project examines this association with survey data representative of the adult population from Ghana’s Coastal Region. Although natural resource scarcity and the sustainability of resource use represent key development challenges, there are others (e.g., energy, sanitation, employment, and educational opportunities). As such, even in the face of natural resource scarcity, individuals may place greater importance on other dimensions of development, especially if household resource strategies are perceived as relatively efficient. The analytical focus here is on water and the results suggest that gender roles shape household water collection strategies, while also shaping these strategies’ perceived opportunity costs. Specifically, Ghanian adults more often see drinking water provision as their primary development need when water sources are distant and/or when male household members collect water (particularly male heads). In the end, I argue that social science inquiry benefits by contextualizing social dynamics within environmental context, particularly within cultural settings in which human subsistence is intimately tied to the state of the natural environment.  相似文献   
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