137 resultados para asset pricing tests
Resumo:
This study explored the validity of using critical thinking tests to predict final psychology degree marks over and above that already predicted by traditional admission exams (A-levels). Participants were a longitudinal sample of 109 psychology students from a university in the United Kingdom. The outcome measures were: total degree marks; and end of year marks. The predictor measures were: university admission exam results (A-levels); critical thinking test scores (skills & dispositions); and non-verbal intelligence scores. Hierarchical regressions showed A-levels significantly predicted 10% of the final degree score and the 11-item measure of ‘Inference skills’ from the California Critical Thinking Skills Test significantly predicted an additional 6% of degree outcome variance. The findings from this study should inform decisions about the precise measurement constructs included in aptitude tests used in the higher education admission process.
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In this paper, we propose new cointegration tests for single equations and panels. Inboth cases, the asymptotic distributions of the tests, which are derived with N fixed andT → ∞, are shown to be standard normals. The effects of serial correlation and crosssectionaldependence are mopped out via long-run variances. An effective bias correctionis derived which is shown to work well in finite samples; particularly when N is smallerthan T. Our panel tests are robust to possible cointegration across units.
Resumo:
The photocatalytic properties of self-cleaning acrylic paint containing TiO2 and ZnO were studied using Acid Orange 7 as a model compound. Paints were exposed to simulated weathering tests in a QUV panel. The initial photoactivity of the unweathered paints with ZnO was significantly higher. In the case of paints containing P25 the photocatalytic activity increases with weathering time, due to increasing destruction of the polymer resin and consequent exposure of the photocatalyst pigment to the Acid Orange 7 test solution. In contrast, in the case of paints containing ZnO, a decrease in photocatalytic activity is observed after weathering, due to the loss and/or photocorrosion of ZnO particles during the weathering process.
Resumo:
Active network scanning injects traffic into a network and observes responses to draw conclusions about the network. Passive network analysis works by looking at network meta data or by analyzing traffic as it traverses a fixed point on the network. It may be infeasible or inappropriate to scan critical infrastructure networks. Techniques exist to uniquely map assets without resorting to active scanning. In many cases, it is possible to characterize and identify network nodes by passively analyzing traffic flows. These techniques are considered in particular with respect to their application to power industry critical infrastructure.
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This paper reports on the accuracy of new test methods developed to measure the air and water permeability of high-performance concretes (HPCs). Five representative HPC and one normal concrete (NC) mixtures were tested to estimate both repeatability and reliability of the proposed methods. Repeatability acceptance was adjudged using values of signal-noise ratio (SNR) and discrimination ratio (DR), and reliability was investigated by comparing against standard laboratory-based test methods (i.e., the RILEM gas permeability test and BS EN water penetration test). With SNR and DR values satisfying recommended criteria, it was concluded that test repeatability error has no significant influence on results. In addition, the research confirmed strong positive relationships between the proposed test methods and existing standard permeability assessment techniques. Based on these findings, the proposed test methods show strong potential to become recognized as international methods for determining the permeability of HPCs.
Resumo:
The properties of blood and the relative ease of access to which it can be retrieved make it an ideal source to gauge different aspects of homeostasis within an individual, form an accurate diagnosis, and formulate an appropriate treatment regime. Tests used to determine blood parameters such as the erythrocyte sedimentation rate, hemoglobin concentration, hematocrit, bleeding and clotting times, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, mean cell volume, and determination of blood groups are routinely used clinically, and deviations outside the normal range can indicate a range of conditions such as anemia, pregnancy, dehydration, overhydration, infectious disease, cancer, thyroid disease, and autoimmune conditions, to mention a few. As these tests can be performed relatively inexpensively and do not require high levels of technical expertise, they are ideally suited for use in the teaching laboratory, enabling undergraduate students to link theory to practice. The practicals described here permit students to examine their own blood and that of their peers and compare these with clinically accepted normal ranges. At the end of the practicals, students are required to answer a number of questions about their findings and to link abnormal values to possible pathological conditions by answering a series of questions based on their findings.
Resumo:
Temperament tests are widely accepted as instruments for profiling behavioral variability in dogs, and they are applied in numerous areas of investigation (e.g. suitability for adoption or for breeding). During testing, to elicit a dog's reaction toward novel stimuli and predict its behavior in everyday life, model devices such as a child-like doll, or a fake dog, are often employed. However, the reliability of these devices to accurately stimulate dogs' reactions to children or dogs, is unknown and perhaps overestimated. This may be a particular concern in the case of aggressive behavior toward humans, a significant public health issue. The aim of this study was to: (1) evaluate the correlation between dogs' reactions to these devices, and owners' reports of their dog's aggression history (using the C-BARQ ??); (2) compare reactions toward the devices of dogs with and without histories of aggression. Subjects were selected among those visiting for behavioral consultation at the Veterinary Hospital of the University of Pennsylvania, and previously categorized as aggressive toward unfamiliar children, conspecifics, or as non-aggressive dogs (control). The test consisted of different components: an unfamiliar female tester approaching the dog; the presentation of a child-like doll, an ambiguous object, and a fake plastic dog. All tests were videotaped and durations of behaviors were later analyzed on the basis of a specified ethogram. Dogs' reactions were compared to C-BARQ scores, and interesting correlations emerged for 'dog-directed aggression/fear' (R = 0.48, P = 0.004), and 'stranger-directed aggression' (R = 0.58, P <0.001) factors. Dogs differed in their reactions toward the devices: the child-like doll and the fake dog elicited more social behaviors than the ambiguous object used as a control stimulus. Issues concerning the reliability of these tools to assess canine temperament are discussed. ?? 2012 Elsevier B.V. All rights reserved.
Resumo:
PURPOSE:
To assess the noneconomic value of tests used in the diagnosis and management of glaucoma, and explore the contexts and factors that determine such value.
DESIGN:
Perspective.
METHODS:
Selected articles from primary and secondary sources were reviewed and interpreted in the context of the authors' clinical and research experience, influenced by our perspectives on the tasks of reducing the global problem of irreversible blindness caused by glaucoma. The value of any test used in glaucoma is addressed by 3 questions regarding: its contexts, its kind of value, and its implicit or explicit benefits.
RESULTS:
Tonometry, slit-lamp gonioscopy, and optic disc evaluation remain the foundation of clinic-based case finding, whether in areas of more or less abundant resources. In resource-poor areas, there is urgency in identifying patients at risk for severe functional loss of vision; screening strategies have proven ineffective, and efforts are hindered by the inadequate allocation of support. In resource-abundant areas, the wider spectrum of glaucoma is addressed, with emphasis on early detection of structural changes of little functional consequence; these are increasingly the focus of new and expensive technologies whose clinical value has not been established in longitudinal and population-based studies. These contrasting realities in part reflect differences among the value ascribed, often implicitly, to the tests used in glaucoma.
CONCLUSIONS:
The value of any test is determined by 3 aspects: its context of usage; its comparative worth and to whom its benefit accrues; and how we define historically what we are testing. These multiple factors
Resumo:
Community asset transfer enables local groups to own or manage a government owned facility and/or related services. For critics, it is merely an extension of roll-back neoliberalism, permitting the state to withdraw from welfare and transfer risk from local government to ill-defined communities. The paper uses quantitative and case study data from Northern Ireland to demonstrate its transformative potential by challenging the notion of private property rights, enabling communities to accumulate and endanger forms of cooperative consumption. It concludes by highlighting the implications for more progressive forms of social economics in relation to public and private markets and government sponsorship of its own development.
Resumo:
Roadside safety barriers designs are tested with passenger cars in Europe using standard EN1317 in which the impact angle for normal, high and very high containment level tests is 20°. In comparison to EN1317, the US standard MASH has higher impact angles for cars and pickups (25°) and different vehicle masses. Studies in Europe (RISER) and the US have shown values for the 90th percentile impact angle of 30°–34°. Thus, the limited evidence available suggests that the 20° angle applied in EN 1317 may be too low.
The first goal of this paper is to use the US NCHRP database (Project NCHRP 17–22) to assess the distribution of impact angle and collision speed in recent ROR accidents. Second, based on the findings of the statistical analysis and on analysis of impact angles and speeds in the literature, an LS-DYNA finite element analysis was carried out to evaluate the normal containment level of concrete barriers in non-standard collisions. The FE model was validated against a crash test of a portable concrete barrier carried out at the UK Transport Research Laboratory (TRL).
The accident data analysis for run-off road accidents indicates that a substantial proportion of accidents have an impact angle in excess of 20°. The baseline LS-DYNA model showed good comparison with experimental acceleration severity index (ASI) data and the parametric analysis indicates a very significant influence of impact angle on ASI. Accordingly, a review of European run-off road accidents and the configuration of EN 1317 should be performed.