Characteristics of homeless jail inmates: Implications for social work

This study set out to validate the hypothesis (belief) that homeless people were likely to commit minor offenses as solutions to their conditions. Jails, and maybe prisons, would provide three meals a day, a place to sleep, and minimal health care-especially during the winter months. Instead, the data did not support the hypothesis. Contrary to the reported practices of some homeless people in Colorado who are described as committing non-serious but timed offenses to go to jail, it found a homeless population in jail who give a literal interpretation to the political phrase the invisible people. They were not in jail because they were homeless, but instead they were in jail for serious crimes (murder, rape, drugs, robbery) and their homelessness was a side fact. Since it was not likely that this group would seek to address or resolve their homelessness, it was recommended that jail social workers identify their needs to them, track them into social welfare networks, with a designated contact person, prior to their release.     

Tail Probability Ratios of Normal and Student’s t Distributions

The ratio of normal tail probabilities and the ratio of Student’s t tail probabilities have gained an increased attention in statistics and related areas. However, they are not well studied in the literature. In this paper, we systematically study the functional behaviors of these two ratios. Meanwhile, we explore their difference as well as their relationship. It is surprising that the two ratios behave very different to each other. Finally, we conclude the paper by conducting some lower and upper bounds for the two ratios.     

Double sample tests for the equality of two means

A double sample (two stage) testing procedure is proposed as an alternative to the usual one stage     

Model selection: some generalized distributions

Many models have been used to represent the distributions of random variables in statistics, engineering, business, and the physical and social science. This paper considers two, four-parameter generalized bea distributions that include nearly all the models actually used as special or limiting cases. Properties and the interrelationships among these distributions are considered. Expressions are reported that facilitate parameter estimation and the analysis of associated means, variances, hazard functions and other distributional characteristics.

Estimation procedures corresponding to different data types are considered. Maximum likelihood estimation is used and the value of the likelihood function provides and important criterion for model selection. The relative performance of the various models is compared for several data sets.     

SINGULAR ELLIPTICAL DISTRIBUTION: DENSITY AND APPLICATIONS

ABSTRACT

The paper present an explicit expression for the density of a n-dimensional random vector with a singular Elliptical distribution. Based on this, the densities of the generalized Chi-squared and generalized t distributions are derived, examining the Pearson Type VII distribution and Kotz Type distribution (as specific Elliptical distributions). Finally, the results are applied to the study of the distribution of the residuals of an Elliptical linear model and the distribution of the t-statistic, based on a sample from an Elliptical population.     

On the generalized t(GT) distribution

McDonald and Newey [J.B. McDonald and W.K. Newey, Partially adaptive estimation of regression models via the generalized t distribution, Econ. Theor. 4 (1988), pp. 428–457.] introduced the generalized t(GT) distribution. In this paper, several explicit formulas for its cumulative distribution function (cdf) are derived. These formulas will be useful for future developments in the theory and applications of the distribution. One such situation is explained and an application is provided to rainfall data from Orlando, Florida.     

理性话语与中国现代文学

在中国现代文学史上,"理性"始终是一个关键词,围绕着这一词语所展开的相关理论表述与创作实践,构成了一个有迹可循、延绵不断的话语体系--"理性话语".而现代中国的这一个核心话语的构建历程,不仅凸现着中国现代文学的审美品格和价值取向,而且也有效地、结构性地规约着其生产动力、运作机制以及主题追求.在考察中国现代文学的理性精神时顾及对现代中国理性话语的考辨应当是对以往研究方法的一种有益补充和新的尝试.     

Independence and t Distribution

The importance of the independence between a standard normal and a chi-square random variable in constructing a t random variable is explored. When independence is absent it is demonstrated that the usual t approximation can lead to misleading results.     

Bayesian Inferences and Forecasts With Multiple Autoregressive Moving Average Models

The main objective of this paper is to develop convenient Bayesian techniques for estimation and forecasting which can be used to analyze multiple (multivariate) autoregressive moving average processes. Based on the conditional likelihood function and the least squares estimates of the residuals, the marginal posterior distribution of the coefficients of the model is approximated by a matrix t distribution, the marginal posterior distribution of the precision matrix is approximated by a Wishart distribution, and the predictive distribution is approximated by a multivariate t distribution. Some numerical examples are given to demonstrate the idea of using the proposed techniques to analyze different types of multiple ARMA models.     

Remarks on the distribution of the sample variance in exponential sampling

Exact expressions for the distribution of the sample variance in exponential sampling are obtained for samples of size 2, 3, and 4. Moments and order of magnitude of the density are considered