On sequential closed testing dose groups with a control

Methods for a sequential test of a dose-response effect in pre-clinical studies are investigated. The objective of the test procedure is to compare several dose groups with a zero-dose control. The sequential testing is conducted within a closed family of one-sided tests. The procedures investigated are based on a monotonicity assumption. These closed procedures strongly control the familywise error rate while providing information about the shape of the dose-responce relationship. Performance of sequential testing procedures are compared via a Monte Carlo simulation study. We illustrae the procedures by application to a real data set.     

Convergence rates for uniform confidence intervals based on local polynomial regression estimators

We investigate the convergence rates of uniform bias-corrected confidence intervals for a smooth curve using local polynomial regression for both the interior and boundary region. We discuss the cases when the degree of the polynomial is odd and even. The uniform confidence intervals are based on the volume-of-tube formula modified for biased estimators. We empirically show that the proposed uniform confidence intervals attain, at least approximately, nominal coverage. Finally, we investigate the performance of the volume-of-tube based confidence intervals for independent non-Gaussian errors.     

Model-Based Classification via Mixtures of Multivariate t-Factor Analyzers

A model-based classification technique is developed, based on mixtures of multivariate t-factor analyzers. Specifically, two related mixture models are developed and their classification efficacy studied. An AECM algorithm is used for parameter estimation, and convergence of these algorithms is determined using Aitken's acceleration. Two different techniques are proposed for model selection: the BIC and the ICL. Our classification technique is applied to data on red wine samples from Italy and to fatty acid measurements on Italian olive oils. These results are discussed and compared to more established classification techniques; under this comparison, our mixture models give excellent classification performance.     

An Improved Boxplot for Univariate Data

The boxplot is an effective data-visualization tool useful in diverse applications and disciplines. Although more sophisticated graphical methods exist, the boxplot remains relevant due to its simplicity, interpretability, and usefulness, even in the age of big data. This article highlights the origins and developments of the boxplot that is now widely viewed as an industry standard as well as its inherent limitations when dealing with data from skewed distributions, particularly when detecting outliers. The proposed Ratio-Skewed boxplot is shown to be practical and suitable for outlier labeling across several parametric distributions.     

Qdf misclassification probabilities for known population parameters

Approximated QDF misclassification probabilities have been derived for bivariate normal populations with known parameter values. Tne effect of unequal covariances and population distance on the misclassification probabilities are examined     

城市群高质量发展背景下人口聚散规律和驱动因素研究

人口与经济协调发展是城市群发展方式更易实现的目标。影响城市群人口聚散的驱动因素有些方面与城市类似:可分为由资源环境决定的内在驱动因素和政策导向、公共服务水平等主导的外在驱动因素。在市场与政府的共同作用下,内在与外在要素分别通过内链与外链形成两条相互影响的驱动路径共同影响人口聚散;有些则不同:城市群内各城市间可通过“规模借用”与“功能借用”实现要素的交换与替代,更易于克服内在和外在驱动因素壁垒,整体实现资本、人力资源等要素的更高配置效率。在对城市群人口聚散规律及驱动因素进行辨析的基础上,利用生产函数构建数理模型,引入资源要素与政策要素,并以首都都市圈中“一核两翼”结构为例进行了仿真分析,探究各驱动要素对人口聚散的作用强度与实现路径。实现人口疏解与承接的关键是提高城市间要素的可替代性与驱动弹性,城市群间可通过合作机制(借用规模)实现要素的交换与替代。在此基础上,提出促进城市群人口数量和分布合理化的思路:正确认识城市群人口承载力与城市功能定位的内涵;以高质量发展战略为契机,强化市场作用,以产业合理布局带动城市间人口合理分布;改革管理体制,降低省际边界障碍和户籍障碍,推进城市群内部的公共服务与基础设施水平均等化,促进形成与城市群和群中各城市功能定位相匹配的人口聚散形式。     

Occupational rehabilitation services provided by a community workers health centre in Hong Kong: a case study

Ergonomics is commonly known as "the scientific study of human work" [14, p. 3] and "the application of scientific information concerning human beings to the design of objects, systems, and environments" (p. 4). The American Occupational Therapy Association defines occupational therapy as "skilled treatment that helps individuals achieve independence in all facets of their lives. It gives people the 'skills for the job of living' necessary for independent and satisfying lives [1]." Both professions share common backgrounds. Occupational therapy has been involved in health care and ergonomics is looking for its place in the health care field.     

The majoritarian compromise is majoritarian-optimal and subgame-perfect implementable

It is shown that the Majoritarian Compromise of Sertel (1986) is subgame-perfect implementable on the domain of strict preference profiles, although it fails to be Maskin-monotonic and is hence not implementable in Nash equilibrium. The Majoritarian Compromise is Pareto-optimal and obeys SNIP (strong no imposition power), i.e. never chooses a strict majority's worst candidate. In fact, it is “majoritarian approving” i.e. it always picks “what's good for a majority” (alternatives which some majority regards as among the better “effective” half of the available alternatives). Thus, being Pareto-optimal and majoritarian approving, it is majoritarian-optimal. Finally, the Majoritarian Compromise is measured against various criteria, such as consistency and Condorcet-consistency. Received: 31 January 1995/Accepted: 22 July 1998     

Age at marriage,sex-ratios,and ethnic heterogamy

"This paper focuses on the effects of age at marriage and the sex-ratio on patterns of ethnic homogamy among Israeli women. We hypothesize that later marriages are more likely than early marriages to be heterogamous as the 'marriage market' shifts from school to the work-place. By the same token, when facing severe marriage squeezes women will be forced to out-marry. Employing data from the 1983 census, we model mate selection of women from Afro-Asian and Euro-American origin in various birth-cohorts. The results do not fully support our hypotheses: we find that in and of itself, age at marriage does not enhance ethnic heterogamy."