On the Spectral Decomposition in Normal Discriminant Analysis

This article enlarges the covariance configurations, on which the classical linear discriminant analysis is based, by considering the four models arising from the spectral decomposition when eigenvalues and/or eigenvectors matrices are allowed to vary or not between groups. As in the classical approach, the assessment of these configurations is accomplished via a test on the training set. The discrimination rule is then built upon the configuration provided by the test, considering or not the unlabeled data. Numerical experiments, on simulated and real data, have been performed to evaluate the gain of our proposal with respect to the linear discriminant analysis.     

On rules based on sample medians for selection of the largest location parameter

The problem of selection of a subset containing the largest of several location parameters is considered, and a Gupta-type selection rule based on sample medians is investigated for normal and double exponential populations. Numerical comparisons between rules based on medians and means of small samples are made for normal and contaminated normal populations, assuming the popula-tion means to be equally spaced. It appears that the rule based on sample means loses its superiority over the rule based on sample medians in case the samples are heavily contaminated. The asymptotic relative efficiency (ARE) of the medians procedure relative to the means procedure is also computed, assuming the normal means to be in a slippage configuration. The means proce-dure is found to be superior to the median procedure in the sense of ARE. As in the small sample case, the situation is reversed if the normal populations are highly contaminate.     

A note on tests for interaction in quantal response data

There are few distribution-free methods for detecting interaction in fixed-dose trials involving quantal response data, despite the fact that such trials are common. We present three new tests to address this issue, including a simple bootstrap procedure. We examine the power of the likelihood ratio test and our new bootstrap test statistic using an innovative linear extrapolation power-estimation technique described in Boos, D. D. and Zhang, J. (2000) in Monte Carlo evaluation of resampling-based hypothesis tests. Journal of the American Statistical Association, 95, 486–492.     

A Monte Carlo study of REML and robust rank-based analyses for the random intercept mixed model

Restricted maximum likelihood (REML) methods are traditionally used for analyzing mixed models. Based on a multivariate normal likelihood, these analyses are sensitive to outliers. Recently developed robust rank-based procedures offer a complete analysis of mixed model: estimation of fixed effects, standard errors, and estimation of variance components. The results of a large Monte Carlo study are presented, comparing these two analyses for many situations over multivariate normal and contaminated normal distributions. The rank-based analyses are much more powerful and efficient than the REML analyses over all non-normal situations, while losing little power for normal errors.     

Rank procedures in many population forced discrimination problems

In this paper the rank method for forced discrimination in two population problems, introduced by Randies, Broffitt, Ramberg and Hogg (1978), is extended to cover settings involving more than two populations. Several methods of ranking are compared to the normal theory procedure in a Monte Carlo study. Asymptotic theory is included which confirms that the rank method does balance the limiting probabilities of misclassification in a two population setting.     

高校思想政治工作研究的基本程序和方法

高校思想政治工作的研究,应遵循一定的科学程序和方法一、选择课题,形成假设;二、制定计划,决定方法;三、整理资料,分析梳理;四、做出结论,撰写报告.如此,大致可达到研究的预期水平.     

Recent and classical tests for normality - a comparative study

We give a critical synopsis of classical and recent tests for univariate normality, our emphasis being on procedures which are consistent against all alternatives. The power performance of some selected tests (Anderson-Darling, Shapiro-Wilk, Shapiro-Francia, Epps-Pulley) is assessed in a simulation study. Numerical results are illuminated by plots of isodynes, i.e., lines of constant estimated power, for the Johnson-system of distributions.     

Research Misconduct Policies of Scientific Journals

The purpose of this study was to gather information on the misconduct policies of scientific journals. We contacted editors from a random sample of 399 journals drawn from the ISI Web of Knowledge database. We received 197 responses (49.4% response rate): 54.8% had a policy, and 47.7% had a formal (written) policy; 28.9% had a policy that only outlined procedures for handling misconduct, 15.7% had a policy that only defined misconduct, 10.2% had a policy that included both a definition and procedures; 26.9% of journals had a policy that was generated by the publisher, 13.2% had a policy that was generated by the journal, and 14.7% had a policy that was generated by another source, such as a professional association. We analyzed the relationship between having a policy and impact factor, field of science, publishing house, and nationality. Impact factor was the only variable with a statistically significant association with having a policy. Impact factor was slightly positively associated with whether or not the publisher had a policy, with an odds ratio of 1.49 (P < .0004) per 10 units increase in the impact factor, with a 95% confidence interval (1.20, 1.88). Our research indicates that more than half of scientific journals have developed misconduct policies, but that most of these policies do not define research misconduct and most of these policies were not generated by the journal.     

Awareness of Elder Abuse Among Community Health and Social Care Staff in Northern Ireland: An Exploratory Study

ABSTRACT

This article reports on one of the first surveys of multi-disciplinary staff awareness of elder abuse in this region of the United Kingdom (UK). Forty staff from eight professional groups in the Southern Health and Services Board area were surveyed about their knowledge of elder abuse, the types of help they thought they could offer the abused and the abuser, and the level of abuse in their current caseload. Thirty-five per cent of respondents had cases of physical, psychological, financial, and sexual abuse as well as care-giver neglect of people aged 65 and over in their caseloads. The findings suggest that while staff had differing levels of awareness of elder abuse, further training is necessary.