One-sided tolerance limits for unbalanced one-way anova andomc effects model

In this article, we investigate techniques for constructing tolerance limits such that the probability is γ that at least _p proportion of the population would exceed that limit. We consider the unbalanced case and study the behavior of the limit as a function of n_i 's (where n_i is the number of observations in the ith batch), as well as that of the variance ratio. To construct the tolerance limits we use the approximation given in Thomas and Hultquist (1978). We also discuss the procedure for constructing the tolerance limits when the variance ratio is unknown. An example is given to illustrate the results.     

SECOND-ORDER ASYMPTOTICS FOR SCORE TESTS IN HETEROSKEDASTIC t REGRESSION MODELS

ABSTRACT

This paper develops corrected score tests for heteroskedastic t regression models, thus generalizing results by Cordeiro, Ferrari and Paula[1] Cordeiro, G.M., Ferrari, S.L.P. and Paula, G.A. 1993. Improved Score Tests for Generalized Linear Models. Journal of the Royal Statistical Society B, 55: 661–674.  [Google Scholar] and Cribari-Neto and Ferrari[2] Cribari-Neto, F. and Ferrari, S.L.P. 1995. Second-order Asymptotics for Score Tests in Generalised Linear Models. Biometrika, 82: 426–432. [Crossref], [Web of Science ®] , [Google Scholar] for normal regression models and by Ferrari and Arellano-Valle[3] Ferrari, S.L.P. and Arellano-Valle, R. 1996. Modified Likelihood Ratio and Score Tests in Linear Regression Models Using the t Distribution. Brazilian Journal of Probability and Statistics, 10: 15–33.  [Google Scholar] for homoskedastic t regression models. We present, in matrix notation, Bartlett-type correction formulae to improve score tests in this class of models. The corrected score statistics have a chi-squared distribution to order n ^?1, where n is the sample size. We apply our main result to a few special models and present simulation results comparing the performance of the usual score tests and their corrected versions.     

Test sizes and the importance of finding global maxima of the likelihood function

This paper demonstrates the importance of taking care to find a global maximum when estimating nuisance parameters required for hypothesis tests. We find that sizes can be badly inflated when this is not done for a test of the general linear regression model.     

A Network Evaluation of Attitudes Toward Gays and Lesbians Among U.S. Military Cadets

The U.S. military's ban on open homosexuality has become an increasingly salient issue since its implementation in 1993 and its repeal in 2011. The military is an organization with a unique professional and social organization. Evaluating military attitudes from a network perspective may offer insight into the role of formal and informal leadership in engendering attitudinal change and cultural tolerance around homosexuality. This study evaluates the role of network centrality and network exposure across formal (command networks) and informal (friendship and perceived leadership networks) structures on attitudes toward homosexuality in the military. This work analyzes survey data from a single cadet company within the U.S. Military Academy (n = 139) prior to the repeal of Don't Ask, Don't Tell. Results indicate that popular students tend to show tolerance toward homosexuality, whereas those who hold command leadership positions are more likely to have personal and professional opposition to homosexuality. In addition, formal superior–subordinate relationships are somewhat more likely to suggest social contagion compared to informal leadership and friendship relationships. Recommendations offer guidance for training strategies particularly with respect to a military leaders and socialization. Future research should monitor these issues relative to the post-DADT environment.     

准确认识“五四”启蒙运动的伟大意义

"五四"启蒙运动与法国启蒙运动之简单比较,它所面临的严峻局势:一方面是民众的远未觉醒,如何消除浓厚的奴性主义意识,树立人权与公民的观念,必须花费巨大的努力.另一方面是它的根本任务,在于要建立自由、平等和民主的现代文明秩序,这样就必须批评与消除传统文明中陈旧和过时的东西,因此就必然会触犯死命维护它的腐败的权势者,受到他们猛烈的反对、攻击和迫害.这样的形势必然会出现激进主义思潮,以便更好做到发聋振聩.陈独秀与鲁迅是这方面的杰出代表,其实他们对于中国传统文明的见解,也还是具有相当全面的观念.而不同于此种范型的杰出启蒙主义者蔡元培,则提出了"思想自由"和兼容并包的主张,这对于启蒙过程的长期性来说, 应该是更为适应的. 林毓生认为"五四"启蒙运动,是全盘否定中国的传统文明,而后来的"文化大革命",则是由它发展而来,此种见解并不符合历史进程的实际情况,不过他提出了一种很值得加以认真讨论的见解,这有利于推动学术研究的向前迈进.     

Ausländer unter Tatverdacht

Findings on the quantity and quality of criminal behavior of immigrant groups differ very widely (partly depending on the source of data used) and interpretations differ according to theoretical standpoint. There is also controversy over the reasons why charges are more often dropped in cases against young non-Germans than in cases against German citizens. Data from prosecution service records were analysed (N = 860 suspects) to investigate whether differences could be found in the quality and structure of the offenses of which Germans and non-Germans were accused, or in the outcome of the investigations. Only marginal differences were found in the quality of offenses with which Germans and non-Germans were charged. The primary reason for the higher rate of charges being dropped against young foreigners was found to be lack of evidence. This need not, however, in any way be interpreted as meaning that young foreigners are more successful at hiding the evidence of their crimes. It could simply show that non-Germans are more often falsely accused of committing a crime.     

Models for Extremal Dependence Derived from Skew‐symmetric Families

Skew‐symmetric families of distributions such as the skew‐normal and skew‐t represent supersets of the normal and t distributions, and they exhibit richer classes of extremal behaviour. By defining a non‐stationary skew‐normal process, which allows the easy handling of positive definite, non‐stationary covariance functions, we derive a new family of max‐stable processes – the extremal skew‐t process. This process is a superset of non‐stationary processes that include the stationary extremal‐t processes. We provide the spectral representation and the resulting angular densities of the extremal skew‐t process and illustrate its practical implementation.     

On an extension of the von Mises distribution due to Batschelet

This paper considers the three-parameter family of symmetric unimodal circular distributions proposed by Batschelet in [1 Batschelet, E. 1981. Circular Statistics in Biology, London: Academic Press.  [Google Scholar]], an extension of the von Mises distribution containing distributional forms ranging from the highly leptokurtic to the very platykurtic. The family's fundamental properties are given, and likelihood-based techniques described which can be used to perform estimation and hypothesis testing. Analyses are presented of two data sets which illustrate how the family and three of its most direct competitors can be applied in the search for parsimonious models for circular data.     

Tests of heteroscedasticity and correlation in multivariate t regression models with AR and ARMA errors

Heteroscedasticity checking in regression analysis plays an important role in modelling. It is of great interest when random errors are correlated, including autocorrelated and partial autocorrelated errors. In this paper, we consider multivariate t linear regression models, and construct the score test for the case of AR(1) errors, and ARMA(s,d) errors. The asymptotic properties, including asymptotic chi-square and approximate powers under local alternatives of the score tests, are studied. Based on modified profile likelihood, the adjusted score test is also developed. The finite sample performance of the tests is investigated through Monte Carlo simulations, and also the tests are illustrated with two real data sets.     

抵抗与沉醉:穆旦《诗八首》的精神分析

《诗八首》通过现代派“复调化”、“戏剧化”的对话技法,揭示出在对既存秩序抵抗的同时,渴望着对一种“新秩序”的沉醉。继承了鲁迅以来自我拷问的精神主题,也是对穆旦进行精神分析的范本。