Approximate Confidence Limits for the Difference between Parameters of Two Pólya Distributions

The problem of calculating approximate confidence limits for the difference between success probability parameters of two Pólya distributions is solved for the first time. We suggest some new methods for determining these approximate confidence limits and consider their application to special cases: namely for the binomial and hypergeometric distributions. The various approximate confidence limits are evaluated and compared.     

A Weighted Composite Dose – Response Model For Human Salmonellosis

This article describes the development of a weighted composite dose – response model for human salmonellosis. Data from previously reported human challenge studies were categorized into two different groups representing low and moderately virulent/pathogenic Salmonella strains based on a disease end point. Because epidemiological data indicate that some Salmonella strains are particularly pathogenic, and in the absence of human feeding study data for such strains, Shigella dysenteriae was used as a proxy for highly virulent strains. Three single-hit dose – response models were applied to the human feeding study data and evaluated for best fit using maximum likelihood estimation: (1) the exponential (E-1pop), (2) the two-subpopulation exponential (E-2pop), and (3) the Beta-Poisson (BP). Based on the goodness-of-fit test, the E-1pop and BP were the best-fit models for low and moderately virulent/pathogenic Salmonella strains, and the E-2pop and BP models were better for highly virulent/pathogenic strains. Epistemic analysis was conducted by determining the degree of confidence associated with the selected models, which was found to be 50%/50% (E-1pop/BP) for low and moderately pathogenic Salmonella strains, and 9.8%/90.2% (E-2pop/BP) for highly virulent strains. The degree of confidence for each component model and variations in the proportion of strains within each virulence/pathogenicity category were incorporated into the overall composite model. This study describes the influence of variation in strain virulence and host susceptibility on the shape of the population dose – response relationship.     

走出“术前签字”制度的困境——从肖志军案切入

按照我国现行的法律制度，在解决肖志军案时应当适用《执业医师法》第24每。但是它在现实中却被《医疗机构管理条例》中确立的“术前签字”制度所架空。试图通过对“术前签字”制度进行革新从而走出“术前签字”的尴尬困境仍然不是一条一劳永逸的良策。只要权利保护的外部成本存在，《执业医师法》第24条就有再次被架空的可能。提高社会信任度，便是破解“术前签字”困局进而激活《执业医师法》第24条最终的钥匙。     

Profile upper Confidence Limits from Discrete Data

When the data are discrete, standard approximate confidence limits often have coverage well below nominal for some parameter values. While ad hoc adjustments may largely solve this problem for particular cases, Kabaila & Lloyd (1997) gave a more systematic method of adjustment which leads to tight upper limits, which have coverage which is never below nominal and are as small as possible within a particular class. However, their computation for all but the simplest models is infeasible. This paper suggests modifying tight upper limits by an initial replacement of the unknown nuisance parameter vector by its profile maximum likelihood estimator. While the resulting limits no longer possess the optimal properties of tight limits exactly, the paper presents both numerical and theoretical evidence that the resulting coverage function is close to optimal. Moreover these profile upper limits are much (possibly many orders of magnitude) easier to compute than tight upper limits.     

Adaptive interval estimation in one-way random effects models

Two-stage procedures are introduced to control the width and coverage (validity) of confidence intervals for the estimation of the mean, the between groups variance component and certain ratios of the variance components in one-way random effects models. The procedures use the pilot sample data to estimate an “optimal” group size and then proceed to determine the number of groups by a stopping rule. Such sampling plans give rise to unbalanced data, which are consequently analyzed by the harmonic mean method. Several asymptotic results concerning the proposed procedures are given along with simulation results to assess their performance in moderate sample size situations. The proposed procedures were found to effectively control the width and probability of coverage of the resulting confidence intervals in all cases and were also found to be robust in the presence of missing observations. From a practical point of view, the procedures are illustrated using a real data set and it is shown that the resulting unbalanced designs tend to require smaller sample sizes than is needed in a corresponding balanced design where the group size is arbitrarily pre-specified.     

英语教学中培养自信、激发兴趣、实现师生互动的手段

自信心是学生进行学习、生活,也是进行创造性学习工作的最重要的心理条件。兴趣是调动学生积极性、探求知识的内动力。只有发挥学生的主体作用,恰当实施兴趣教学,使"要我学"变为"我要学",才能提高课堂效率,达到较好的教学效果。     

道德信心优先性与培植方法探讨

一个社会道德水准的高低，主要不是由它所倡导的道德规范体系标示，而是通过其成员在社会活动中的行为方式体现。如果进步和完善的道德规范得不到社会公众的普遍信任，行为主体的道德选择持有疑虑、信心缺失，那么再好的道德规范也不能发挥实际作用，社会的道德水准也不能真正提高。目前，公民道德信心正在经历严峻考验，培植公民的道德信心是当下道德建设的首要任务。文章着重探讨道德信心优先性的表现以及如何利用综合性的社会资源维护和维持公民的道德信心。     

Estimating population sizes by catch-effort methods

Estimating population sizes by the catch-effort methods is of enormous importance, in particular to harvest animal populations. A unified mixture model is introduced for different catchability functions to account for heterogeneous catchabilities among individual animals. A sequence of lower bounds to the odds that a single animal is not caught are proposed and used to define pseudo maximum likelihood estimators for the population size. The one-sided nature of confidence intervals is discussed. The proposed estimation methods are presented and illustrated by numerical studies.     

浅议民国时期第一届国会的弹劾权

《临时约法》变总统制为内阁制,但对内阁制特有的不信任投票权却没有具体规定。《临时约法》设计者将不信任投票权和弹劾权混同,目的是以国会制约政府权力,自身又不被解散。可在国会真正需要行使不信任投票权时,或因弹劾手续烦琐不能奏效,或因没有法律依据而无所适从,不仅不能制约政府,反而因无法可依而相当被动。     

Inference for general parametric functions in box‐Cox‐type transformation models

The authors propose a simple but general method of inference for a parametric function of the Box‐Cox‐type transformation model. Their approach is built upon the classical normal theory but takes parameter estimation into account. It quickly leads to test statistics and confidence intervals for a linear combination of scaled or unsealed regression coefficients, as well as for the survivor function and marginal effects on the median or other quantité functions of an original response. The authors show through simulations that the finite‐sample performance of their method is often superior to the delta method, and that their approach is robust to mild departures from normality of error distributions. They illustrate their approach with a numerical example.