997 resultados para 13627-005
Resumo:
This paper, chosen as a best paper from the 2005 SAMOS Workshop on Computer Systems: describes the for the first time the major Abhainn project for automated system level design of embedded signal processing systems. In particular, this describes four key novelties: novel algorithm modelling techniques for DSP systems, automated implementation realisation, algorithm transformation for system optimisation and automated inter-processor communication. This is applied to two complex systems: a radar and sonar system. In both cases technology which allows non-experts to automatically create low-overhead, high performance embedded signal processing systems is exhibited.
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The paper deals with use of a food grade coagulant (guar gum) as a replacement for synthetic coagulants for potable water treatment.
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The work presented is concerned with the estimation of manufacturing cost at the concept design stage, when little technical information is readily available. The work focuses on the nose cowl sections of a wide range of engine nacelles built at Bombardier Aerospace Shorts of Belfast. A core methodology is presented that: defines manufacturing cost elements that are prominent; utilises technical parameters that are highly influential in generating those costs; establishes the linkage between these two; and builds the associated cost estimating relations into models. The methodology is readily adapted to deal with both the early and more mature conceptual design phases, which thereby highlights the generic, flexible and fundamental nature of the method. The early concept cost model simplifies cost as a cumulative element that can be estimated using higher level complexity ratings, while the mature concept cost model breaks manufacturing cost down into a number of constituents that are each driven by their own specific drivers. Both methodologies have an average error of less that ten percent when correlated with actual findings, thus achieving an acceptable level of accuracy. By way of validity and application, the research is firmly based on industrial case studies and practice and addresses the integration of design and manufacture through cost. The main contribution of the paper is the cost modelling methodology. The elemental modelling of the cost breakdown structure through materials, part fabrication, assembly and their associated drivers is relevant to the analytical design procedure, as it utilises design definition and complexity that is understood by engineers.
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In experiments at the high-power Z-facility at Sandia National Laboratory in Albuquerque, New Mexico, we have been able to produce a low density photoionized laboratory plasma of Fe mixed with NaF. The conditions in the experiment allow a meaningful comparison with X-ray emission from astrophysical sources. The charge state distributions of Fe, Na and F are determined in this plasma using high resolution X-ray spectroscopy. Independent measurements of the density and radiation flux indicate unprecedented values for the ionization parameter xi = 20-25 erg cm s(-1) under nearly steady-state conditions. First comparisons of the measured charge state distributions with X-ray photoionization models show reasonable agreement, although many questions remain.
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Using a before and after study design, we compared protocolised weaning from mechanical ventilation with usual non-protocolised practice in intensive care. Outcomes (duration of mechanical ventilation, duration of intubation, intensive care stay) and complications (re-intubations, tracheostomy, mortality) were compared between baseline (Phase I) and following implementation of protocolised weaning (Phase II). Over the same period, we collected data in a second (reference) unit to monitor practice changes over time. In the intervention unit, outcomes were longer in Phase II compared with Phase I (all p < 0.005). When adjusted for admission APACHE II score and diagnostic category, only intensive care stay remained significantly longer (p = 0.002). There were significantly more tracheostomies in Phase II (p = 0.004). The reference unit demonstrated no statistically significant differences in study outcomes or complications between Phases. Protocolised weaning did not reduce the duration of mechanical ventilation and was not associated with an increased rate of re-intubation or intensive care unit mortality.
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Background: Hip protectors are protective pads designed to cover the greater trochanter and attenuate or disperse the force of a fall sufficiently to prevent a hip fracture. Promising results from randomised controlled trials in nursing homes have resulted in hip protectors being widely recommended in the health care literature and in national guidelines. Objectives: The objectives of the study were to identify characteristics of individual residents, and the organisational features of the homes in which they live, which may affect adherence to wearing hip protectors. Design: An observational, correlation study designed to identify factors related to adherence. Setting: Forty nursing and residential homes in the UK. Participants: 1346 residents of the homes who were not confined to bed and with no pressure sore on the hip. Methods: The introduction of an evidence-based policy to offer Safehips hip protectors to residents free of charge and with support from a nurse facilitator. Adherence to wearing the hip protectors was observed over 72 weeks. Results: Initial acceptance of the hip protectors was 37.2%. Continued adherence was 23.9% at 24 weeks; 23.2% at 48 weeks; and 19.9% at 72 weeks. Greater adherence was associated with the following individual resident characteristics: a greater degree of dependency (95% CI 1.39 - m3.78) and cognitive impairment (95% CI 1.01 - 2.98); being male rather than female (95% CI 1.06 - 2.48). Greater adherence was also associated with the following organisational characteristics of homes: fewer changes of senior manager during the study period (95% CI 1.01 - 8.51), and being resident in a home with a resident profile showing a greater proportion of residents with a higher degree of dependency (95% CI 1.04 - 1.27). There was wide a variation in the degree of success in implementation between homes (adherence of 0 - 100% at 24 weeks). Conclusions: Those implementing a policy of introducing hip protectors into nursing and residential homes should consider targeting residents with cognitive impairment. Such residents are at greater risk of hip fracture and appear to be more likely to continue wearing hip protectors. Those charged with implementing changes inpractice or policy should consider how the context for implementation can be optimised to increase the likelihood of success.
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A dielectric barrier discharge (DBD) generated by flowing helium between the parallel-plate electrodes of an open air reactor has been characterized using time resolved optical and electrical measurements. A sinusoidal voltage of up to 5 kV (peak to peak) of frequencies from 3 to 50 kHz has been applied to the discharge electrodes. The helium flow rate is varied up to 10 litre min(-1). The adjustment of flow rate allows the creation of uniform DBDs with optimized input power equal to 120 +/- 10 mW cm(-3). At flow rates from 4 to 6 litre min(-1) a uniform DBD is obtained. The maxima in the line intensities of N-2(+) and helium at 391.4 nm and 706.5 nm, respectively, 2 under those conditions indicate the importance of helium metastables and He-2(+) in sustaining such a discharge. The power efficiency and discharge 2 current show maxima when the DBD In He/air is uniform. The gas temperature during the discharge has been measured as 360 +/- 20 K.