New results on the likelihood ratio and score tests for the von Mises distribution

In this paper, we derive Bartlett and Bartlett-type corrections [G.M. Cordeiro and S.L.P. Ferrari 1991, A modified score test statistic having chi-squared distribution to order n ^?1 , Biometrika 78 (1991), pp. 573–582] to improve the likelihood ratio and Rao's score statistics for testing the mean parameter and the concentration parameter in the von Mises distribution. Simple formulae are suggested for the corrections valid for small and large values of the concentration parameter that do not depend on the modified Bessel functions and can be useful in practical applications.     

“So Tell Me,Why Do Women Need Something Different?”

SUMMARY

There has been a dramatic increase in the number of women in the criminal justice system over the past two decades, creating the need for gender-specific responses and programs in jails, prisons, and community corrections. Systems must adapt to appropriately respond to women and their families. Institutions and community-based organizations must help women to deal with their histories of trauma, violence, and substance abuse. One gender-specific, strength-based, community model for support is presented.     

A Statewide Parenting Alternative Sentencing Program: Description and Preliminary Outcomes

ABSTRACT

The Washington State Legislature created the Parenting Sentencing Alternative in 2010, authorizing a substitute to total confinement for parents of minor children. The Alternative is designed to strengthen family bonds and improve parenting skills to encourage successful reintegration. An overview of the Alternative’s history, design, and implementation is presented, followed by preliminary results from an impact evaluation. A case study of a successful participant is presented, and implications for the findings are discussed.     

Testing equality of generalized variances of k multivariate normal populations

Generalized variance is a measure of dispersion of multivariate data. Comparison of dispersion of multivariate data is one of the favorite issues for multivariate quality control, generalized homogeneity of multidimensional scatter, etc. In this article, the problem of testing equality of generalized variances of k multivariate normal populations by using the Bartlett's modified likelihood ratio test (BMLRT) is proposed. Simulations to compare the Type I error rate and power of the BMLRT and the likelihood ratio test (LRT) methods are performed. These simulations show that the BMLRT method has a better chi-square approximation under the null hypothesis. Finally, a practical example is given.     

BARTLETT CORRECTED LIKELIHOOD RATIO TESTS IN LOCATION-SCALE NONLINEAR MODELS

The paper derives Bartlett corrections for improving the chisquare approximation to the likelihood ratio statistics in a class of location-scale family of distributions, which encompasses the elliptical family of distributions and also asymmetric distributions such as the extreme value distributions. We present, in matrix notation, a Bartlett corrected likelihood ratio statistic for testing that a subset of the nonlinear regression coefficients in this class of models equals a given vector of constants. The formulae derived are simple enough to be used analytically to obtain several Bartlett corrections in a variety of important models. We show that these formulae generalize a number of previously published results. We also present simulation results comparing the sizes and powers of the usual likelihood ratio tests and their Bartlett corrected versions when the scale parameter is considered known and when this parameter is uncorrectly specified.     

Elliptically contoured model and factorization of wllks1 A

In a series of papers, Kshirsagar (1964, 1971) and McHenry and Kshirsagar (1977), factorize Wilks' A into a number of factors and find the independent null multivariate beta densities of these factors. These factors are the likelihood ratio test criteria for testing the goodness of fit of certain assigned discriminant functions or canonical variables either in the space of independent or dependent variables. Essentially the factors of Wilks' A are the factors of certain multivariate beta distributed matrix or its determinant. The Bartlett decomposition of the underlying multivariate beta distribution into independent factors determines the distribution of these factors. The present paper generalizes Kshirsagar's (1971) normal theory to the elliptically contoured model, and shows that his results are null robust for the elliptically contoured model.     

Comments

In this paper we compare Bartlett-corrected, bootstrap, and fast double bootstrap tests on maximum likelihood estimates of cointegration parameters. The key result is that both the bootstrap and the Bartlett-corrected tests must be based on the unrestricted estimates of the cointegrating vectors: procedures based on the restricted estimates have almost no power. The small sample size bias of the asymptotic test appears so severe as to advise strongly against its use with the sample sizes commonly available; the fast double bootstrap test minimizes size bias, while the Bartlett-corrected test is somehow more powerful.     

社区矫正中的检察监督

社区矫正作为一种新的刑罚执行方式,在我国处于试点的阶段。实施对社区矫正的法律监督,是检察机关的一项重要任务。检察机关充分发挥社区矫正检察监督职能,对促进严格执法和公正司法,保障刑罚的依法执行,维护社会和谐稳定,促进社会长治久安具有重要的意义。但社区矫正中的检察监督面临各种难题:检察机关履行监督缺失具体规定、检察机关监督的事后性、检察机关的监督手段单一等,这些问题给社区矫正检察监督工作带来不便,影响了检察监督的效果。因此,检察机关要落实"宽严相济"刑事政策,才能切实履行好社区矫正的监督职能,维护矫正对象合法权益,为创造和谐稳定的社会环境做出新的贡献。     

点校本《宋刑统》补正十五则

今存宋《刑统》在长期的流传过程中文字有衍、脱、误 ,中华书局点校出版的《宋刑统》对律文及疏议进行了补正 ,惜未及附入令、式、格、敕、起请条。本文依据有关文献 ,对其中的十五则十七条予以补正     

社区矫正对象的社会关系支持网络分析——以上海市某三个街道为例

以上海市某三个街道的实地调研资料为基础,对社区矫正对象的社会关系支持网络的特征与类型进行分析,可以发现社工是矫正对象社会关系支持的首要来源,特别在矫正对象的求职过程中,社工起到了非常重要的作用。