1,274 research outputs found

    A functional analysis of change propagation

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    A thorough understanding of change propagation is fundamental to effective change management during product redesign. A new model of change propagation, as a result of the interaction of form and function is presented and used to develop an analysis method that determines how change is likely to propagate. The analysis produces a Design Structure Matrix, which clearly illustrates change propagation paths and highlights connections that could otherwise be ignored. This provides the user with an in-depth knowledge of product connectivity, which has the potential to support the design process and reduce the product's susceptibility to future change

    The application of reliability methods in the design of stiffened FRP composite panels for marine vessels

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    The use of composite laminate materials has increased rapidly in recent years due to their excellent strength to weight ratio and resistance to corrosion. In the construction of marine vessels, stiffened plates are the most commonly used structural elements, forming the deck, bottom hull, side shells and bulkheads. This paper presents the use of a stochastic approach to the design of stiffened marine composite panels as part of a current research programme into developing stochastic methods for composite ship structures, accounting for variations in material properties, geometric indices and processing techniques, from the component level to the full system level. An analytical model for the solution of a stiffened isotropic plate using a grillage analogy is extended by the use of equivalent elastic properties for composite modelling. This methodology is applied in a reliability analysis of an isotropic (steel) stiffened plate before the final application for a reliability analysis for a FRP composite stiffened plate

    Linear-time nearest point algorithms for Coxeter lattices

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    The Coxeter lattices, which we denote An/mA_{n/m}, are a family of lattices containing many of the important lattices in low dimensions. This includes AnA_n, E7E_7, E8E_8 and their duals AnA_n^*, E7E_7^* and E8E_8^*. We consider the problem of finding a nearest point in a Coxeter lattice. We describe two new algorithms, one with worst case arithmetic complexity O(nlogn)O(n\log{n}) and the other with worst case complexity O(n) where nn is the dimension of the lattice. We show that for the particular lattices AnA_n and AnA_n^* the algorithms reduce to simple nearest point algorithms that already exist in the literature.Comment: submitted to IEEE Transactions on Information Theor

    Novel Approaches to Developing On-Farm Biomass Production Systems

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    Energy security and climate change are issues facing many countries today. Finding clean, renewable fuel sources has provided a challenge to look beyond the obvious and search for new ways to use old resources. Switchgrass (Panicum virgatum L.) is a warm season grass native to many parts of the United States. In 2007, the University of Kentucky (UK) College of Agriculture started a collaborative project with the UK Cooperative Extension, farmers in northern Kentucky, Kentucky Forage and Grassland Council and East Kentucky Power Cooperative to explore and demonstrate how switchgrass can be grown, harvested and utilized in an economical and environmentally friendly way (Greenwell 2012a,b). This pilot project was funded by the KY Agricultural Development Fund and successfully established 60 ha of switchgrass between 2007-2011 and produced \u3e 500 t of biomass that was combusted for electricity production. Switchgrass was chosen as the biomass crop of choice for this area for a variety of reasons. It can be grown on marginal soils that are not well suited to row crops. It produces high yields with relatively low inputs and can be harvested with equipment that is common on typical US farms. Because it is a native grass, there is little concern of it becoming invasive and it provides wildlife habitat for local animal species. Additionally, when harvested at a vegetative stage, it produces high quality forage

    Participant recruitment to FiCTION, a primary dental care trial – survey of facilitators and barriers

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    Objective To identify reasons behind a lower than expected participant recruitment rate within the FiCTION trial, a multi-centre paediatric primary dental care randomised controlled trial (RCT). Subjects (materials) and methods An online survey, based on a previously published tool, consisting of both quantitative and qualitative responses, completed by staff in dental practices recruiting to FiCTION. Ratings from quantitative responses were aggregated to give overall scores for factors related to participant recruitment. Qualitative responses were independently grouped into themes. Results Thirty-nine anonymous responses were received. Main facilitators related to the support received from the central research team and importance of the research question. The main barriers related to low child eligibility rates and the integration of trial processes within routine workloads. Conclusions These findings have directed strategies for enhancing participant recruitment at existing practices and informed recruitment of further practices. The results help provide a profile of the features required of practices to successfully screen and recruit participants. Future trials in this setting should consider the level of interest in the research question within practices, and ensure trial processes are as streamlined as possible. Research teams should actively support practices with participant recruitment and maintain enthusiasm among the entire practice team

    The vulnerability of public spaces: challenges for UK hospitals under the 'new' terrorist threat

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    This article considers the challenges for hospitals in the United Kingdom that arise from the threats of mass-casualty terrorism. Whilst much has been written about the role of health care as a rescuer in terrorist attacks and other mass-casualty crises, little has been written about health care as a victim within a mass-emergency setting. Yet, health care is a key component of any nation's contingency planning and an erosion of its capabilities would have a significant impact on the generation of a wider crisis following a mass-casualty event. This article seeks to highlight the nature of the challenges facing elements of UK health care, with a focus on hospitals both as essential contingency responders under the United Kingdom's civil contingencies legislation and as potential victims of terrorism. It seeks to explore the potential gaps that exist between the task demands facing hospitals and the vulnerabilities that exist within them

    INTEGRAL deep observations of the Small Magellanic Cloud

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    Deep observations of the Small Magellanic Cloud (SMC) and region were carried out in the hard X-ray band by the INTEGRAL observatory in 2008-2009. The field of view of the instrument permitted simultaneous coverage of the entire SMC and the eastern end of the Magellanic Bridge. In total, INTEGRAL detected seven sources in the SMC and five in the Magellanic Bridge; the majority of the sources were previously unknown systems. Several of the new sources were detected undergoing bright X- ray outbursts and all the sources exhibited transient behaviour except the supergiant system SMC X-1. They are all thought to be High Mass X-ray Binary (HMXB) systems in which the compact object is a neutron star.Comment: 7 pages, 10 figures Accepted for publication in MNRA

    The thermal emission of the exoplanets WASP-1b and WASP-2b

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    We present a comparative study of the thermal emission of the transiting exoplanets WASP-1b and WASP-2b using the Spitzer Space Telescope. The two planets have very similar masses but suffer different levels of irradiation and are predicted to fall either side of a sharp transition between planets with and without hot stratospheres. WASP-1b is one of the most highly irradiated planets studied to date. We measure planet/star contrast ratios in all four of the IRAC bands for both planets (3.6-8.0um), and our results indicate the presence of a strong temperature inversion in the atmosphere of WASP-1b, particularly apparent at 8um, and no inversion in WASP-2b. In both cases the measured eclipse depths favor models in which incident energy is not redistributed efficiently from the day side to the night side of the planet. We fit the Spitzer light curves simultaneously with the best available radial velocity curves and transit photometry in order to provide updated measurements of system parameters. We do not find significant eccentricity in the orbit of either planet, suggesting that the inflated radius of WASP-1b is unlikely to be the result of tidal heating. Finally, by plotting ratios of secondary eclipse depths at 8um and 4.5um against irradiation for all available planets, we find evidence for a sharp transition in the emission spectra of hot Jupiters at an irradiation level of 2 x 10^9 erg/s/cm^2. We suggest this transition may be due to the presence of TiO in the upper atmospheres of the most strongly irradiated hot Jupiters.Comment: 10 pages, submitted to Ap

    Exploring the meaning in meaningful coincidences: an interpretative phenomenological analysis of synchronicity in therapy

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    Synchronicity experiences (SEs) are defined as psychologically meaningful connections between inner events (e.g. thought, dream or vision) and one or more external events occurring simultaneously or at a future point in time. There has been limited systematic research that has investigated the phenomenology of SEs in therapy. This study aimed to redress this by exploring the process and nature of such experiences from the perspective of the practitioner. Semi-structured face-to-face interviews were conducted with a purposive sample of nine practitioners who reported SEs in their therapeutic sessions (three counsellors, three psychologists and three psychotherapists), and focused on how participants make sense of their experiences of synchronicity in therapy. Interpretative phenomenological analysis was used to identify three superordinate themes: sense of connectedness, therapeutic process, and professional issues. Findings suggest that SEs can serve to strengthen the therapeutic relationship and are perceived as useful harbingers of information about the therapeutic process, as well as being a means of overcoming communication difficulties, as they are seen to provide insights into the client’s experiencing of themselves and others, regardless of whether or not the SE is acknowledged by the client or disclosed by the therapist

    A randomised controlled trial to explore attitudes to routine scale and polish and compare manual versus ultrasonic scaling in the general dental service in Scotland [ISRCTN99609795]

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    BACKGROUND: To investigate, within general dental practice, patients' and vocational dental practitioners' (VDP) attitudes towards the benefits and costs of a simple scale and polish and to compare the experience of using manual versus ultrasonic instruments to scale teeth. METHODS: 28 VDPs and 420 patients participated. Patients were randomly allocated to either group. Patients' and VDPs' attitudes towards, and experience of, the scale and polish were elicited by means of self-administered questionnaires. RESULTS: The majority of patients (99%) believed a scale and polish was beneficial. VDPs considered ultrasonic treatment to be appropriate on significantly more occasions than they did for manual scale and polish (P < 0.001). Patient discomfort: with ultrasonic scaling 69.2% felt 'a little uncomfortable' or worse compared with 60% of those undergoing manual treatment (P = 0.072). VDPs considered treatment charges were appropriate for 77% of patients. CONCLUSION: Routine scaling and polishing is considered beneficial by both patients and vocational trainees. The majority of patients, regardless of treatment method, experience some degree of discomfort when undergoing a scale and polish. VDPs showed a preference for the ultrasonic treatment method
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