1,450 research outputs found

    Solving the Discretised Boltzmann Transport Equations using Neural Networks: Applications in Neutron Transport

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    In this paper we solve the Boltzmann transport equation using AI libraries. The reason why this is attractive is because it enables one to use the highly optimised software within AI libraries, enabling one to run on different computer architectures and enables one to tap into the vast quantity of community based software that has been developed for AI and ML applications e.g. mixed arithmetic precision or model parallelism. Here we take the first steps towards developing this approach for the Boltzmann transport equation and develop the necessary methods in order to do that effectively. This includes: 1) A space-angle multigrid solution method that can extract the level of parallelism necessary to run efficiently on GPUs or new AI computers. 2) A new Convolutional Finite Element Method (ConvFEM) that greatly simplifies the implementation of high order finite elements (quadratic to quintic, say). 3) A new non-linear Petrov-Galerkin method that introduces dissipation anisotropically

    Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study. Volume 2: Appendices

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    The current status of the Active Controls Technology (ACT) for the advanced subsonic transport project is investigated through analysis of the systems technical data. Control systems technologies under examination include computerized reliability analysis, pitch axis fly by wire actuator, flaperon actuation system design trade study, control law synthesis and analysis, flutter mode control and gust load alleviation analysis, and implementation of alternative ACT systems. Extensive analysis of the computer techniques involved in each system is included

    Prehabilitation is feasible in patients with rectal cancer undergoing neoadjuvant chemoradiotherapy and may minimize physical deterioration:Results from the REx trial

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    Aim: Rectal cancer patients undergoing neoadjuvant chemoradiotherapy (NACRT) experience physical deterioration and reductions in their quality of life. This feasibility study assessed prehabilitation (a walking intervention) before, during and after NACRT to inform a definitive multi-centred randomized clinical trial (REx trial). Methods: Patients planned for NACRT followed by potentially curative surgery were approached (August 2014–March 2016) (www.isrctn.com; 62859294). Prior to NACRT, baseline physical and psycho-social data were recorded using validated tools. Participants were randomized to either the intervention group (exercise counselling session followed by a 13–17 week telephone-guided walking programme) or a control group (standard care). Follow-up testing was undertaken 1–2 weeks before surgery. Results: Of the 296 screened patients, 78 (26%) were eligible and 48 (61%) were recruited. N = 31 (65%) were men with a mean age of 65.9 years (range 33.7–82.6). Mean intervention duration was 14 weeks with 75% adherence. n = 40 (83%) completed follow-up testing. Both groups recorded reductions in daily walking but the reduction was less in the intervention group although not statistically significant. Participants reported high satisfaction and fidelity to trial procedures. Conclusion: This study demonstrates that prehabilitation is feasible in rectal cancer patients undergoing NACRT. Good recruitment, adherence, retention and patient satisfaction rates support the development of a fully powered trial. The effects of the intervention on physical outcomes were promising

    Utility of international normative 20 m shuttle run values for identifying youth at increased cardiometabolic risk

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    The purpose of this study was to examine the ability of international normative centiles for the 20 m shuttle run test (20mSRT) to identify youth at increased cardiometabolic risk. This was a cross-sectional study involving 961 children aged 10–17 years (53% girls) from the United Kingdom. Receiver operating characteristic (ROC) curves determined the discriminatory ability of cardiorespiratory fitness percentiles for predicting increased cardiometabolic risk. ROC analysis demonstrated a significant but poor discriminatory accuracy of cardiorespiratory fitness in identifying low/high cardiometabolic risk in girls (AUC = 0.58, 95% CI: 0.54–0.63; p = 0.04), and in boys (AUC = 0.59, 95% CI: 0.54–0.63; p = 0.03). The cardiorespiratory fitness cut-off associated with high cardiometabolic risk was the 55th percentile (sensitivity = 33.3%; specificity = 84.5%) in girls and the 60th percentile (sensitivity = 42.9%; specificity = 73.6%) in boys. These 20mSRT percentile thresholds can be used to identify children and adolescents who may benefit from lifestyle intervention. Nonetheless, further work involving different populations and cardiometabolic risk scores comprising of different variables are needed to confirm our initial findings

    A new skilled emigration dynamic: Portuguese nurses and recruitment in the southern European periphery

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    Philippine and Indian nurses have been emigrating for many years, but Portu-guese nurses and other South and East Europeans have recently started to replace them in the UK. This study focuses on the recent migration of Portuguese nurses – both as emigrants and immigrants – within the European area. The research mixes extensive and intensive methodologies. Health agencies start-ed to recruit heavily among Portuguese nurses after 2008, which often led to their decision to leave the country with a guaranteed job abroad. In turn, this dynamic of emigration being motived by institutional and recruitment networks was caused by a structural factor: the barriers erected in 2010 by UK immigration pol-icies against the contracting of nurses from outside the EU, which led the job agencies to search for nurses inside Europe. The chapter’s main finding is that alt-hough the push factor of economic recession and increased unemployment that hit the European periphery after the 2008 financial crisis played a role in the out-flow of Portuguese nurses, it was the pull factor that was more significant. The second finding is that this new mass emigration of nurses is not just a Portuguese phenomenon but rather is in keeping with other Southern and East European pe-ripheral countries.info:eu-repo/semantics/publishedVersio

    Adaptive Haar wavelets for the angular discretisation of spectral wave models

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    A new framework for applying anisotropic angular adaptivity in spectral wave modelling is presented. The angular dimension of the action balance equation is discretised with the use of Haar wavelets, hierarchical piecewise-constant basis functions with compact support, and an adaptive methodology for anisotropically adjusting the resolution of the angular mesh is proposed. This work allows a reduction of computational effort in spectral wave modelling, through a reduction in the degrees of freedom required for a given accuracy, with an automated procedure and minimal cost
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