Fourier methods for analyzing piecewise constant volatilities

AStA Advances in Statistical Analysis - We develop procedures for testing whether a sequence of independent random variables has constant variance. If this is fulfilled, the modulus of a...     

Prevention of MSD by means of ergonomic risk assessment (tools) in all phases of the vehicle development process

In industrialized countries musculoskeletal disorders (MSD) play an import role and are often responsible for almost one third of the total sick leave. The changes in the demographic profiles, i.e. aging work forces might even worsen this situation in the future. For a highly productive and sustainable use of human resources in production systems, ergonomics offers high potentials. In the recent years the authors have developed several ergonomic risk assessment tools, especially for the use in automotive industries. These methods may be used during the planning phases in the Tech Centers as well as during the production phase at shop floor level. The tools might also be used for a standardized communication in between the Tech Center and the plants to improve the effects of "lessons learned" for the design and layout of workstations and processes and the optimization of vehicle components. This paper describes suitable risk assessment tools as well as the integration of these tools into the vehicle development process. It introduces a comprehensive management approach for the integration of ergonomics into the management of production systems.     

Gender Differences Among Helpline Callers: Prospective Study of Gambling and Psychosocial Outcomes

Despite the increasing amount of empirical research on gambling helplines (e.g., characteristics, effectiveness), little is known about gender differences on treatment outcomes following contact. The present research addresses this gap in the literature via secondary analysis of an uncontrolled outcome study of New Zealand’s gambling helpline (N = 150). To this end, the present research had three aims; (a) explore gender differences (e.g., demographics, co-morbidities, gambling variables) among helpline callers using psychometrically robust measures, (b) assess whether gender predicts treatment utilization following contact and (c) assess whether systematic gender differences exist on gambling and psychosocial outcomes at 3-, 6- and 12-month follow-ups. The results revealed that at baseline, women compared to men, described greater problem severity and shorter problem duration, and were more likely to report electronic gaming machines as their most problematic form of gambling. Women also reported greater distress and lower quality of life. Men, despite less problem severity and distress, were more likely to access treatment following helpline contact. Importantly, both men and women reported significant and equivalent improvements in both gambling and psychosocial outcomes following helpline contact. The improved outcomes remained significant after controlling for treatment attendance. Although different approaches for women may be required by helplines if the goal is to refer callers to treatment, the results suggest that after calling the helpline, women reduced their problematic gambling and improved psychosocial functioning without further treatment.     

Metropolitan migration efficiency

The migration efficiency ratio of an area is defined as the net migration of the area (in-migrants minus out-migrants) divided by the total number of moves whose origin or destination is that area (in-migrants plus out-migrants) multiplied by 100. This paper investigates variations in migration efficiency from 1955 to 1960 among Standard Metropolitan Statistical Areas with populations of 250,000 or more. Regional variation in migration efficiency was evident, ranging from an average of ?9.7 in the Northeast to 19.6 for SMSA’s in the Western region. Nonwhites tended to have higher migration efficiency than whites. Rapidly growing metropolitan areas had higher migration efficiency ratios than areas growing at a lower rate or losing population. The educational level of a metropolitan area, as measured by the percent of the population 25 years old or over with at least a high school education, was positively related to migration efficiency. The composition of the migrant population, both in- and outmigrants for a given area, was related to the value of the migration efficiency ratio. If the migrant population contained a large proportion of persons aged 20–34, migration efficiency was low, regardless of the direction of the major migration stream. Region was found to have a major effect. Variables that had a strong and positive relationship with migration efficiency in one region were usually found to have no relation, or a negative relation, with it in other areas. Obviously, further research is needed for the identification of factors producing these strong regional effects.     

A Probabilistic Analysis of the Passive–Restraint Question

The benefits and costs of automobile safety policies are compared using a methodology which explicitly quantifies the uncertainties. The policies addressed include both voluntary and compulsory manual belt usage, nondetachable passive (automatic) seat belts, and air bags. Estimates of the effectiveness and usage rates of these alternatives were obtained in the form of subjective probability distributions from eight experts. Their opinions were combined using equal weighting. The direct economic costs of the technologies were also estimated probabilistically. The number of lives saved and the net benefits of the policies were calculated probabilistically for a range of values of lifesaving. Probabilistic computations and sensitivity analysis were performed by the Demos modelling system using Monte Carlo simulation. The results are highly uncertain and quite sensitive to the value of lifesaving. Nevertheless, they imply that repeal of the passive-restraint standard is defensible according to the net-benefit criterion only if a relatively low value is assigned to lifesaving. The degree of uncertainty emphasizes the potential value of demonstration programs to obtain better information.     

Partisanship and Views about Immigration in Southern California: Just How Partisan is the Issue of Immigration?

ALLÉGEANCE PARTISANE ET POINTS DE VUE SUR L'IMMIGRATION EN CALIFORNIE DU SUD: LA QUESTION DE L'IMMIGRATION EST-ELLE ASSOCIÉE À UNE ATTITUDE PARTISANE ?
Étant donné les divisions partisanes qu'affichent les élites politiques sur la question de l'immigration, on peut s'attendre, sur ce même sujet, à voir l'attitude des masses reproduire les mêmes clivages. Nous étudions l'incidence de l'attitude partisane sur cette question en analysant les attitudes populaires à l'égard des immigrants en Californie, oú le regard porté sur l'immigration et les immigrants a été au centre de campagnes éminemment politiques. Pourtant, même en Californie, nous constatons que des types très différents d'électeurs partagent des préoccupations étonnamment semblables face à l'immigration. Nous nous intéressons tout particulièrement à la question de savoir si les démocrates et les républicains perçoivent de façon semblable ou différente l'incidence de l'immigration sur l'action des pouvoirs publics. Nous constatons que, comme on pouvait s'y attendre, les républicains ont davantage tendance à penser que l'immigration aura des effets néfastes sur les plans social et politique aux États-Unis, mais aussi que les démocrates tendent à partager les mêmes préoccupations. Cette tendance a pour conséquence que le Parti républicain - tout du moins en Californie - pourrait être en mesure d'utiliser la question de l'immigration pour obtenir l'adhésion de personnes qui soutiennent habituellement les candidates démocrates, censés être plus ouverts à l'égard des immigrants.