239 research outputs found

    Parallel solution of power system linear equations

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    At the heart of many power system computations lies the solution of a large sparse set of linear equations. These equations arise from the modelling of the network and are the cause of a computational bottleneck in power system analysis applications. Efficient sequential techniques have been developed to solve these equations but the solution is still too slow for applications such as real-time dynamic simulation and on-line security analysis. Parallel computing techniques have been explored in the attempt to find faster solutions but the methods developed to date have not efficiently exploited the full power of parallel processing. This thesis considers the solution of the linear network equations encountered in power system computations. Based on the insight provided by the elimination tree, it is proposed that a novel matrix structure is adopted to allow the exploitation of parallelism which exists within the cutset of a typical parallel solution. Using this matrix structure it is possible to reduce the size of the sequential part of the problem and to increase the speed and efficiency of typical LU-based parallel solution. A method for transforming the admittance matrix into the required form is presented along with network partitioning and load balancing techniques. Sequential solution techniques are considered and existing parallel methods are surveyed to determine their strengths and weaknesses. Combining the benefits of existing solutions with the new matrix structure allows an improved LU-based parallel solution to be derived. A simulation of the improved LU solution is used to show the improvements in performance over a standard LU-based solution that result from the adoption of the new techniques. The results of a multiprocessor implementation of the method are presented and the new method is shown to have a better performance than existing methods for distributed memory multiprocessors

    The Role of Gamification in a Software Development Lifecycle

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    Teaching Software Engineering students raises a number of challenges; in particular that student developers typically demonstrate behaviours that run counter to good software development. These include failing to plan properly, failing to develop their software in a structured manner, and failing to meet specified deadlines (so called "student syndrome"). Consequentially, students exhibiting these behaviours are more likely to disengage from their studies. Even where submissions are made, they tend to be lower in quality, and may not demonstrate the true capabilities of the individual. Such alienation and disengagement is amplified by the current context of learning in a pandemic, with a wall of digital communication technology coming between teachers and learners. In this paper, the authors will identify how gamification approaches can be applied to software development education, and how they can help to better motivate and educate future software developers through computer managed delivery and assessment. As motivation is a key factor, motivational properties known in computer gaming are applied within the new context of a software engineering lifecycle. The role of intrinsic and extrinsic motivation for developers is considere. The gamified techniques identified are further enhanced with an Agile type approach. This has been particularly critical during 2020/21 where the shift to fully online learning for previously face to face taught students has placed new pressures on students and staff.

    Discovering antiviral restriction factors and pathways using genetic screens

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    Research in the Hughes lab is supported by a grant from the Academy of Medical Sciences (SFB003/1028), a grant from Tenovus Scotland (T20/63), and The Wellcome Trust Institutional Strategic Support Fund (ISSF). Research in the Gray lab is supported Medical Research Council (MR/N001796/1) and the Biotechnology and Biological Sciences Research Council (BBS/E/D/20002172). C. E. J. is supported by a University of St Andrews Ph.D. scholarship.Viral infections activate the powerful interferon (IFN) response that induces the expression of several hundred IFN stimulated genes (ISGs). The principal role of this extensive response is to create an unfavourable environment for virus replication and to limit spread; however, untangling the biological consequences of this large response is complicated. In addition to a seemingly high degree of redundancy, several ISGs are usually required in combination to limit infection as individual ISGs often have low to moderate antiviral activity. Furthermore, what ISG or combination of ISGs are antiviral for a given virus is usually not known. For these reasons, and that the function(s) of many ISGs remains unexplored, genome-wide approaches are well placed to investigate what aspects of this response results in an appropriate, virus-specific phenotype. This review discusses the advances screening approaches have provided for the study of host defence mechanisms, including CRISPR/Cas9, ISG expression libraries and RNAi technologies.Publisher PDFPeer reviewe

    A consensus epitope prediction approach identifies the breadth of murine T CD8+ -cell responses to vaccinia virus

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    The value of predictive algorithms for identifying CD8+ T (TCD8+)-cell epitopes has not been adequately tested experimentally. Here we demonstrate that conventional bioinformatic methods predict the vast majority of TCD8+-cell epitopes derived from vaccinia virus WR strain (VACV-WR) in the H-2b mouse model. This approach reveals the breadth of T-cell responses to vaccinia, a widely studied murine viral infection model, and may provide a tool for developing comprehensive antigenic maps of any complex pathogen

    A Tablet-based Virtual Environment for Neurosurgery Training

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    Published in Presence: Teleoperators and Virtual Environments, Spring 2015No. 2, Pages 155-162 Posted Online October 15, 2015. doi:10.1162/PRES_a_00224The requirement for training surgical procedures without exposing the patient to additional risk is well accepted and is part of a national drive in the UK and internationally. Computer-based simulations are important in this context, including neurosurgical resident training. The objective of this study is to evaluate the effectiveness of a custom built virtual environment in assisting training of a ventriculostomy procedure. The training tool (called VCath) has been developed as an app for a tablet platform to provide easy access and availability to trainees. The study was conducted at the first boot camp organized for all year one trainees in neurosurgery in the UK. The attendees were randomly distributed between the VCath training group and the Control group. Efficacy of performing ventriculostomy for both groups was assessed at the beginning and end of the study using a simulated insertion task. Statistically significant changes in performance of selecting the burr hole entry point, the trajectory length and duration metrics for the VCath group, together with a good indicator of improved normalized jerk (representing the speed and smoothness of arm motion), all suggest that there has been a higher level cognitive benefit to using VCath. The app is successful as it is focused on the cognitive task of ventriculostomy, encouraging the trainee to rehearse the entry point and use anatomical landmarks to create a trajectory to the target. In straight-line trajectory procedures such as ventriculostomy, cognitive task based education is a useful adjunct to traditional methods and may reduce the learning curve and ultimately improve patient safety

    Intensive Cognitive Therapy for PTSD: A Feasibility Study

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    Background: Cognitive Behaviour Therapy (CBT) of anxiety disorders is usually delivered in weekly or biweekly sessions. There is evidence that intensive CBT can be effective in phobias and obsessive compulsive disorder. Studies of intensive CBT for posttraumatic stress disorder (PTSD) are lacking. Method: A feasibility study tested the acceptability and efficacy of an intensive version of Cognitive Therapy for PTSD (CT-PTSD) in 14 patients drawn from consecutive referrals. Patients received up to 18 hours of therapy over a period of 5 to 7 working days, followed by 1 session a week later and up to 3 follow-up sessions. Results: Intensive CT-PTSD was well tolerated and 85.7 % of patients no longer had PTSD at the end of treatment. Patients treated with intensive CT-PTSD achieved similar overall outcomes as a comparable group of patients treated with weekly CT-PTSD in an earlier study, but the intensive treatment improved PTSD symptoms over a shorter period of time and led to greater reductions in depression. Conclusions: The results suggest that intensive CT-PTSD is a feasible and promising alternative to weekly treatment that warrants further evaluation in randomized trials

    Investigation of International Space Station Major Constituent Analyzer Anomalous ORU 02 Performance

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    The Major Constituent Analyzer (MCA) is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. In 2011, two MCA ORU 02 analyzer assemblies experienced premature on-orbit failures. These failures were determined to be the result of off-nominal ion source filament performance. Recent product improvements to ORU 02 designed to improve the lifetime of the ion pump also constrained the allowable tuning criteria for the ion source filaments. This presentation describes the filament failures as well as the corrective actions implemented to preclude such failures in the future

    Lifespan extension and the doctrine of double effect

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    Recent developments in biogerontology—the study of the biology of ageing—suggest that it may eventually be possible to intervene in the human ageing process. This, in turn, offers the prospect of significantly postponing the onset of age-related diseases. The biogerontological project, however, has met with strong resistance, especially by deontologists. They consider the act of intervening in the ageing process impermissible on the grounds that it would (most probably) bring about an extended maximum lifespan—a state of affairs that they deem intrinsically bad. In a bid to convince their deontological opponents of the permissibility of this act, proponents of biogerontology invoke an argument which is grounded in the doctrine of double effect. Surprisingly, their argument, which we refer to as the ‘double effect argument’, has gone unnoticed. This article exposes and critically evaluates this ‘double effect argument’. To this end, we first review a series of excerpts from the ethical debate on biogerontology in order to substantiate the presence of double effect reasoning. Next, we attempt to determine the role that the ‘double effect argument’ is meant to fulfil within this debate. Finally, we assess whether the act of intervening in ageing actually can be justified using double effect reasoning
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