Test procedure of islanding prevention measures for utility-interconnected photovoltaic inverters

2011 ◽  
Keyword(s):  
Test Procedure ◽  
Prevention Measures

Perception of Smokers: Results from the Tobacco Monitoring Switzerland

2011 ◽  
Vol 57 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Theda Radtke ◽  
Roger Keller ◽  
Andrea Bütikofer ◽  
Rainer Hornung
Keyword(s):  
Social Ties ◽  
Tobacco Consumption ◽  
School Transitions ◽  
Prevention Measures

Aim: The purpose of the study is to present adolescents’ perceptions of smokers and non-smokers among 1015 Swiss adolescents. Method: The analyses are based on data from Tobacco Monitoring Switzerland, which is a survey of tobacco consumption in Switzerland. To measure the perceptions of smokers and non-smokers, respondents were asked to attribute a series of adjectives to each group. It was also recorded when respondents mentioned that “there is no difference between smokers and non-smokers.” Results: Results show that regardless of whether the adolescents smoked or did not smoke – with the exception of more sociable – the image of smokers was more negative than the image of non-smokers. Findings also indicated that regular smokers in particular often stated that there are no differences between both groups. Conclusions: Overall, the image of smokers is more negative than the image of non-smokers, with the exception of the attribute more sociable. This perception of smokers could be important for prevention measures in new contexts (e. g., school transitions), where smoking could be a means of establishing new social ties.

Benefits from Computerized Adaptive Testing as Seen in Simulation Studies

1999 ◽  
Vol 15 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Lutz F. Hornke
Keyword(s):  
Measurement Error ◽  
Computerized Adaptive Testing ◽  
Test Procedure ◽  
Adaptive Testing ◽  
Parameter Estimates ◽  
Simulation Studies ◽  
Computerized Adaptive Test ◽  
Item Banks ◽  
Item Parameters ◽  
General Reliability

Summary: Item parameters for several hundreds of items were estimated based on empirical data from several thousands of subjects. The logistic one-parameter (1PL) and two-parameter (2PL) model estimates were evaluated. However, model fit showed that only a subset of items complied sufficiently, so that the remaining ones were assembled in well-fitting item banks. In several simulation studies 5000 simulated responses were generated in accordance with a computerized adaptive test procedure along with person parameters. A general reliability of .80 or a standard error of measurement of .44 was used as a stopping rule to end CAT testing. We also recorded how often each item was used by all simulees. Person-parameter estimates based on CAT correlated higher than .90 with true values simulated. For all 1PL fitting item banks most simulees used more than 20 items but less than 30 items to reach the pre-set level of measurement error. However, testing based on item banks that complied to the 2PL revealed that, on average, only 10 items were sufficient to end testing at the same measurement error level. Both clearly demonstrate the precision and economy of computerized adaptive testing. Empirical evaluations from everyday uses will show whether these trends will hold up in practice. If so, CAT will become possible and reasonable with some 150 well-calibrated 2PL items.

Family-, Media-, and School-Related Risk Factors of Video Game Addiction

2013 ◽  
Vol 25 (3) ◽  
pp. 118-128 ◽  
Author(s):  
Florian Rehbein ◽  
Dirk Baier
Keyword(s):  
Risk Factors ◽  
Video Game ◽  
Age Groups ◽  
Well Being ◽  
Epidemiological Studies ◽  
Prevention Measures ◽  
School Life ◽  
Video Game Addiction ◽  
Effective Prevention ◽  
Game Addiction

In recent years, a variety of epidemiological studies have provided empirical data on the prevalence of video game addiction (GA) in different age groups. However, few studies investigated the causes of GA and could explain why video game playing as a widespread phenomenon leads to a comparatively small percentage of addicted players. Additionally, the existing longitudinal studies mainly consider psychological trait variables and neglect the possible explanatory value of predictors in socialization regarding media availability, media use, and family and everyday school life. In this paper, the results of a two-wave longitudinal study comprising a sample of students from Grades 4 to 9 (N = 406) are presented. The data show that 15-year-old video game addicts had already exhibited a number of specific risk factors at the age of 10. Students from single-parent families seem to be particularly at risk, as are students with low experienced school well-being and with a weaker social integration in class. The data also indicate that problematic use of video games in childhood increases the risk of GA in adolescence. Male students are especially vulnerable for developing GA. The results of this study are an important contribution to understanding risk factors for GA in adolescents, thereby laying the groundwork for effective prevention measures.

Evaluating the Validity of a Bayesian Program for Predicting Stage in Hodgkin’s Disease

1981 ◽  
Vol 20 (03) ◽  
pp. 174-178 ◽  
Author(s):  
A. I. Barnett ◽  
J. Cynthia ◽  
F. Jane ◽  
Nancy Gutensohn ◽  
B. Davies
Keyword(s):  
New England ◽  
Hodgkin's Disease ◽  
Bayesian Model ◽  
Medical Center ◽  
Hodgkin’S Disease ◽  
Test Procedure ◽  
Disease Patient ◽  
Probabilistic Information ◽  
Probabilistic Forecasts ◽  
England Medical

A Bayesian model that provides probabilistic information about the spread of malignancy in a Hodgkin’s disease patient has been developed at the Tufts New England Medical Center. In assessing the model’s reliability, it seemed important to use it to make predictions about patients other than those relevant to its construction. The accuracy of these predictions could then be tested statistically. This paper describes such a test, based on 243 Hodgkin’s disease patients of known pathologic stage. The results obtained were supportive of the model, and the test procedure might interest those wishing to determine whether the imperfections that attend any attempt to make probabilistic forecasts have gravely damaged their accuracy.

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