4 resultados para Empirical Predictions
em Brock University, Canada
Resumo:
Research suggests that self-blame attributions are important in the process of adjustment to negative life events. Much of the research originates from JanofTBulman's (1979) theory regarding behavioural and characterological self-blame. She argued that attributing negative events to one's behaviour is adaptive because behavioural self-blame involves attributions to a modifiable source, which implies that a similar event can be avoided in the future. In contrast, attributing negative events to one's character is believed to be maladaptive because character is seen as relatively stable and unmodifiable. Unfortunately, the empirical literature does not show consistent relations between these two types of self-blame attributions and well-being as predicted by Janoff-Bulman. For this thesis, I proposed that one reason for this inconsistency is that Janoff-Bulman's assumption about the perceived modifiability of behavioural versus characterological causes is incorrect — people often dlo perceive character (as well as behaviour) to be modifiable. Sixty-two participants completed a questionnaire regarding a recent negative life event and its impact on their well-being. Consistent with my argument, I found that both behavioural and characterological self-blame attributions following a negative life event were seen as modifiable. As hypothesized, perceived modifiability of causes v^as related to well-being. For example, overall modifiability was related to greater coping efficacy, less social dysfunction, less severe depression, and greater positive affect; however. contrary to predictions, the relation between perceived modifiability of causes and wellbeing was not mediated by the perception that similar events could be avoided in the future. Individual differences in attributional style were also assessed in this study. An attributional style that tended to be more internal, stable, and specific was related to wellbeing as expected; however, neither the perceived modifiability of blame attributions nor the perceived avoidability of similar future events mediated this relation. Implications for professionals dealing with trauma victims and potential directions for future research are discussed.
Resumo:
We study the phonon dispersion, cohesive and thermal properties of raxe gas solids Ne, Ar, Kr, and Xe, using a variety of potentials obtained from different approaches; such as, fitting to crystal properties, purely ab initio calculations for molecules and dimers or ab initio calculations for solid crystalline phase, a combination of ab initio calculations and fitting to either gas phase data or sohd state properties. We explore whether potentials derived with a certain approaxih have any obvious benefit over the others in reproducing the solid state properties. In particular, we study phonon dispersion, isothermal ajid adiabatic bulk moduli, thermal expansion, and elastic (shear) constants as a function of temperatiue. Anharmonic effects on thermal expansion, specific heat, and bulk moduli have been studied using A^ perturbation theory in the high temperature limit using the neaxest-neighbor central force (nncf) model as developed by Shukla and MacDonald [4]. In our study, we find that potentials based on fitting to the crystal properties have some advantage, particularly for Kr and Xe, in terms of reproducing the thermodynamic properties over an extended range of temperatiures, but agreement with the phonon frequencies with the measured values is not guaranteed. For the lighter element Ne, the LJ potential which is based on fitting to the gas phase data produces best results for the thermodynamic properties; however, the Eggenberger potential for Ne, where the potential is based on combining ab initio quantum chemical calculations and molecular dynamics simulations, produces results that have better agreement with the measured dispersion, and elastic (shear) values. For At, the Morse-type potential, which is based on M0ller-Plesset perturbation theory to fourth order (MP4) ab initio calculations, yields the best results for the thermodynamic properties, elastic (shear) constants, and the phonon dispersion curves.
Resumo:
The purpose of this study was to determine if there were differences between in-school and out-of-school day care centres. Five centres housed in public schools and five housed in other locations were selected for the research. Aquality assessment was administered in each centre which examined the following components - physical environment, adult social structure and socia-emotional environment, children's socia-emotional environment, cognitive stimulation program and toys and equipment. Quantitative analysis using simple t-tests showed a significant difference between in-school and out-of-school day cares for the physical environment variable. Differences approached significance for the children's socia-emotional environment variable as well as overall quality. Qualitative analysis using a triangulated methodology revealed noticeable differences for every variable. The researcher concluded that both the quality of the physical environment and the capabilities of the administrators strongly influence the quality of the day care environment. This study also included an assessment of children's attitude toward learning. No significant difference was found between in-school and out-of-school centres.
Resumo:
The purpose of this study is to examine the impact of the choice of cut-off points, sampling procedures, and the business cycle on the accuracy of bankruptcy prediction models. Misclassification can result in erroneous predictions leading to prohibitive costs to firms, investors and the economy. To test the impact of the choice of cut-off points and sampling procedures, three bankruptcy prediction models are assessed- Bayesian, Hazard and Mixed Logit. A salient feature of the study is that the analysis includes both parametric and nonparametric bankruptcy prediction models. A sample of firms from Lynn M. LoPucki Bankruptcy Research Database in the U. S. was used to evaluate the relative performance of the three models. The choice of a cut-off point and sampling procedures were found to affect the rankings of the various models. In general, the results indicate that the empirical cut-off point estimated from the training sample resulted in the lowest misclassification costs for all three models. Although the Hazard and Mixed Logit models resulted in lower costs of misclassification in the randomly selected samples, the Mixed Logit model did not perform as well across varying business-cycles. In general, the Hazard model has the highest predictive power. However, the higher predictive power of the Bayesian model, when the ratio of the cost of Type I errors to the cost of Type II errors is high, is relatively consistent across all sampling methods. Such an advantage of the Bayesian model may make it more attractive in the current economic environment. This study extends recent research comparing the performance of bankruptcy prediction models by identifying under what conditions a model performs better. It also allays a range of user groups, including auditors, shareholders, employees, suppliers, rating agencies, and creditors' concerns with respect to assessing failure risk.