154 resultados para Measuring instruments.
Resumo:
In this paper we consider the consequences for measurement of material deprivation, consistent poverty and economic vulnerability of the shift from the ECHP data set to the EU-SILC instrument. Despite the restricted number of deprivation items available in EU-SILC, we show that there is a substantial overlap between such measures when they are estimated using EU-wide and a set of Irish specific indicators. By placing the EU-wide measures in the context of the full range of Irish indicators, we demonstrate that they allow us to identify clusters of individuals sharply differentiated in terms of their multidimensional deprivation profiles. They also provide an understanding of the socio-economic factors associated with such differentiation that departs in only modest respects from that derived from the more comprehensive set of Irish specific indicators.
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Behavioural synchrony has been a popular topic of research in group living animals, but has so far lacked a standard approach. Previous studies have varied greatly in the number of behavioural states they have considered and the size of groups investigated. Here, a model of behavioural synchrony was used to test four measures of synchrony commonly used (proportion observations 100% conforming, mean proportion of conforming individuals, Ruckstuhl's group mean and the kappa coefficient). The model used scan samples of the behaviour of laying hens, originally categorised in 10 different behavioural states, as a basis for determining the agents' probability of performing behaviour states. We systematically varied the group size and the number of behavioural states in the model. The measures calculated from the behaviour of the model agents were compared against a synchrony factor that determined the 'motivation' of agents in the model to conform to the behaviour of other agents, for model runs with different group sizes and behavioural categories. The results of the model suggest that, of the measures considered, the kappa coefficient is the most suitable measure of synchrony. The kappa coefficient was the only measure of the four tested to control for expected levels of synchrony. Expected levels of synchrony are sensitive to both the number of behaviour states being examined and the size of the group, therefore observed levels of synchrony should be compared against expected levels to provide meaningful standardised measures. © 2012 Elsevier B.V.
Resumo:
Data obtained with any research tool must be reproducible, a concept referred to as reliability. Three techniques are often used to evaluate reliability of tools using continuous data in aging research: intraclass correlation coefficients (ICC), Pearson correlations, and paired t tests. These are often construed as equivalent when applied to reliability. This is not correct, and may lead researchers to select instruments based on statistics that may not reflect actual reliability. The purpose of this paper is to compare the reliability estimates produced by these three techniques and determine the preferable technique. A hypothetical dataset was produced to evaluate the reliability estimates obtained with ICC, Pearson correlations, and paired t tests in three different situations. For each situation two sets of 20 observations were created to simulate an intrarater or inter-rater paradigm, based on 20 participants with two observations per participant. Situations were designed to demonstrate good agreement, systematic bias, or substantial random measurement error. In the situation demonstrating good agreement, all three techniques supported the conclusion that the data were reliable. In the situation demonstrating systematic bias, the ICC and t test suggested the data were not reliable, whereas the Pearson correlation suggested high reliability despite the systematic discrepancy. In the situation representing substantial random measurement error where low reliability was expected, the ICC and Pearson coefficient accurately illustrated this. The t test suggested the data were reliable. The ICC is the preferred technique to measure reliability. Although there are some limitations associated with the use of this technique, they can be overcome.
Resumo:
The efficiency of fuel cells and metal-air batteries is significantly limited by the activation of oxygen reduction and evolution reactions. Despite the well-recognized role of oxygen reaction kinetics on the viability of energy technologies, the governing mechanisms remain elusive and until now have been addressable only by macroscopic studies. This lack of nanoscale understanding precludes optimization of material architecture. Here, we report direct measurements of oxygen reduction/evolution reactions and oxygen vacancy diffusion on oxygen-ion conductive solid surfaces with sub-10 nm resolution. In electrochemical strain microscopy, the biased scanning probe microscopy tip acts as a moving, electrocatalytically active probe exploring local electrochemical activity. The probe concentrates an electric field in a nanometre-scale volume of material, and bias-induced, picometre-level surface displacements provide information on local electrochemical processes. Systematic mapping of oxygen activity on bare and platinum-functionalized yttria-stabilized zirconia surfaces is demonstrated. This approach allows direct visualization of the oxygen reduction/evolution reaction activation process at the triple-phase boundary, and can be extended to a broad spectrum of oxygen-conductive and electrocatalytic materials.
Resumo:
PURPOSE: To identify vision Patient-Reported Outcomes instruments relevant to glaucoma and assess their content validity.
METHODS: MEDLINE, MEDLINE in Process, EMBASE and SCOPUS (to January 2009) were systematically searched. Observational studies or randomised controlled trials, published in English, reporting use of vision instruments in glaucoma studies involving adults were included. In addition, reference lists were scanned to identify additional studies describing development and/or validation to ascertain the final version of the instruments. Instruments' content was then mapped onto a theoretical framework, the World Health Organization International Classification of Functioning, Disability and Health. Two reviewers independently evaluated studies for inclusion and quality assessed instrument content.
RESULTS: Thirty-three instruments were identified. Instruments were categorised into thirteen vision status, two vision disability, one vision satisfaction, five glaucoma status, one glaucoma medication related to health status, five glaucoma medication side effects and six glaucoma medication satisfaction measures according to each instruments' content. The National Eye Institute Visual Function Questionnaire-25, Impact of Vision Impairment and Treatment Satisfaction Survey-Intraocular Pressure had the highest number of positive ratings in the content validity assessment.
CONCLUSION: This study provides a descriptive catalogue of vision-specific PRO instruments, to inform the choice of an appropriate measure of patient-reported outcomes in a glaucoma context.
Resumo:
We propose an interferometric setting for the ancilla-assisted measurement of the characteristic function of the work distribution following a time-dependent process experienced by a quantum system. We identify how the configuration of the effective interferometer is linked to the symmetries enjoyed by the Hamiltonian ruling the process and provide the explicit form of the operations to implement in order to accomplish our task. We finally discuss two physical settings, based on hybrid optomechanical-electromechanical devices, where the theoretical proposals discussed in our work could find an experimental demonstration.
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This paper descirbes a simple test measuring the sorptivity (a measure of the absorption property if concrete) and the air and water permeability of concrete on site. Using this test, the decay of pressure is monitired for the air permeability test.whereas water penetrating into the concrete at a constant pressure of 0.01 bar and 1.5 bar are recorded for the sorptivity and the water permeability tests respectively. These tests are essentially non-destructive in nature and a skilled operator is not needed. It is possible to carry out a number of tests quickly and efficiently on site without prior planning. It has been found that statistically satisfactory results can be obtained from a mean of three tests. As the flow lines are largely concentrated within 40 mm from the surface, reasonably reliable results can be obtained by drying the surface even if the surface under test is initially wet.
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This paper introduces a series of new musical instruments that have been designed to
address questions relating to performative virtuosity in the area of ensemble-based
improvisation. The intentionally exploited inconsistent nature of these instruments<br/>raises questions around traditional notions of instrument mastery and opens up
possible methods of recon?guring the performer-instrument relationship.
Resumo:
Pretensioned concrete members are designed and manufactured by using at least two materials: concrete and prestressing reinforcement. Also, two main stages must be considered: prestress transfer and member loading. Hence, the behavior of these members depends strongly on the reinforcement-to-concrete bond performance and prestress losses. In this paper, a testing technique to measure the specific parameters related with the involved phenomena is presented. The testing technique is based on the analysis of series of specimens varying in embedment length to simulate several cross sections at only one end of a pretensioned concrete member. Each specimen is characterized by means of the sequential release of the prestress transfer (detensioning) and the pull-out (loading) operation. The test provides data on prestressing force, transmission length (initial and long-term), anchorage length (without and with slip), reinforcement slips, bond stresses, longitudinal concrete strains, concrete modulus of elasticity, and prestress losses (instantaneous and time-dependent).