Computer experiments: a review

In this paper we provide a broad introduction to the topic of computer experiments. We begin by briefly presenting a number of applications with different types of output or different goals. We then review modelling strategies, including the popular Gaussian process approach, as well as variations and modifications. Other strategies that are reviewed are based on polynomial regression, non-parametric regression and smoothing spline ANOVA. The issue of multi-level models, which combine simulators of different resolution in the same experiment, is also addressed. Special attention is given to modelling techniques that are suitable for functional data. To conclude the modelling section, we discuss calibration, validation and verification. We then review design strategies including Latin hypercube designs and space-filling designs and their adaptation to computer experiments. We comment on a number of special issues, such as designs for multi-level simulators, nested factors and determination of experiment size.     

Autocorrelation in real-time continuous monitoring of microenvironments

Interpretation of continuous measurements in microenvironmental studies and exposure assessments can be complicated by autocorrelation, the implications of which are often not fully addressed. We discuss some statistical issues that arose in the analysis of microenvironmental particulate matter concentration data collected in 1998 by the Harvard School of Public Health. We present a simulation study that suggests that Generalized Estimating Equations, a technique often used to adjust for autocorrelation, may produce inflated Type I errors when applied to microenvironmental studies of small or moderate sample size, and that Linear Mixed Effects models may be more appropriate in small-sample settings. Environmental scientists often appeal to longer averaging times to reduce autocorrelation. We explore the functional relationship between averaging time, autocorrelation, and standard errors of both mean and variance, showing that longer averaging times impair statistical inferences about main effects. We conclude that, given widely available techniques that adjust for autocorrelation, longer averaging times may be inappropriate in microenvironmental studies.     

Psychopathology and pathological gambling among males: Theoretical and clinical concerns

In this paper, some possible relationships between psychopathology and pathological gambling are delineated. The assessment and stabilization of such patients, including psychotherapeutic and pharmacologic strategies, are discussed. Guidelines for treating patients manifesting both a psychiatric illness and a gambling problem are suggested.     

The effects of driving age, driver education, and curfew laws on traffic fatalities of 15-17 year olds

This study examines the effect of state driving age, learning permit, driver's education, and curfew laws on 15-17-year-old driver fatality rates. A multivariate regression model is estimated for 47 states and nine years. The minimum legal driving age and curfew laws are found to be important determinants of fatalities. Driver's education and learning permits have smaller effects. The relationship between rates of licensure and driving age, education, and curfew laws is also examined. In each case, a more restrictive policy is found to reduce licensure of 15-17 year olds. The results suggest that the imposition of curfew laws and higher minimum driving ages are particularly effective traffic safety policies.     

Bayesian analysis of prevalence from the results of small screening samples

Bayesian analysis is applied to the number of cases screened positive to estimate the disease prevalence and to predict the number of future cases with disease. The analysis makes use of additional experimental information about the test’s sensitivity and specificity and of prior information on the prevalence of disease. Prior and posterior probability distributions of disease prevalence are conjugate mixtures of Beta densities and can be expressed in exact algebraic form.     

A condition for best asymptotic normality in a regular family of distributions

A theorem is presented which provides a simple sufficient condition for a weakly consistent estimator of a parameter in a regular family of distributions to be best asymptotically normal (B.A.N.). As a corollary the B.A.N. property of a maximum likelihood estimator is established under weaker conditions than those of Zacks (1971). Two examples are provided to illustrate the technique.     

SOCIAL STRUCTURE AND GENERATIONS IN ART:

This study examines artistic innovations from the point of view of age structure and age stratification. Drawing on Mannheim's theory of generations, it describes and analyzes the history of the Hebrew theater, from its beginnings in 1917 to 1977, in terms of four theaters that were expressions of generation units. The study suggests that the crucial variable in explaining changes in artistic ideologies, contents, and styles of the Hebrew theater is Mannheim's concept of generation unit. The emergence and evolution of these generational theaters are explained in relation to changes in the demographic, political, and social structures of Israeli society during the historical era under consideration. Special emphasis is placed on the role of youth in originating artistic innovations and on the problems of maintaining and institutionalizing innovations.     

Gambling Disorder in Veterans: A Review of the Literature and Implications for Future Research

To review the scientific literature examining gambling behavior in military veterans in order to summarize factors associated with gambling behavior in this population. Database searches were employed to identify articles specifically examining gambling behavior in military veterans. Cumulative search results identified 52 articles (1983–2017) examining gambling behavior in veteran populations. Articles generally fell into one or more of the following categories: prevalence, psychological profiles and psychiatric comorbidities, treatment evaluations, measurement, and genetic contributions to gambling disorder. Results from reviewed articles are presented and implications for future research discussed. Research to date has provided an excellent foundation to inform potential screening, intervention and research activities going forward. The authors suggest that a public health approach to future research endeavors would strengthen the evidence base regarding gambling in veteran populations and better inform strategies for screening, prevention and treatment.     

Life satisfaction—Aspirations and alcohol use: A preliminary report

Significant differences have been found to exist among individuals with different drinking patterns with respect to past life satisfactions — five years ago (p < 0.001) and present satisfaction (p < 0.005); however, no significant difference in future aspirations could be identified. In addition, using an ‘unrealistic hopefulness’ coefficient, the authors found higher future aspirations levels than would be normally expected. Those individuals who drink more now than five years ago consistently show the lowest mean satisfaction scores on the Cantril Self-Anchoring Striving Scale. Those whose drinking pattern remained stable over time consistently perceived themselves highest on the scale both five years ago and now, regardless of present drinking pattern. At the time this article was written Drs Levy and Bell and Ms Lin were with the University of Louisville, Department of Psychiatry & Behavioral Sciences. Dr Levy is now with the Sepulveda VA Hospital, LA, California. Reprints may be obtained through Dr Levy.