1,252 research outputs found

    Aerodynamic characteristics of a 1/6-scale model of the rotor systems research aircraft with the rotors removed

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    A wind-tunnel investigation was conducted to refine the aerodynamic characteristics of the rotor systems research aircraft. For the investigation, a 1/6-scale model without a main rotor or a tail rotor was used. The model provided the capability for testing different engine nacelle sizes, engine pylon fairings, and tail configurations. The engine thrust effects were modeled by small engine simulators (fans). Data were obtained primarily over an angle-of-attack range from -13 deg to 13 deg at several values of sideslip. Stability characteristics and control effectiveness were investigated. The model with the scaled engine nacelles and the combination T-tail and lower horizontal tail displayed longitudinal and lateral-directional stability. Results show that by reducing the horizontal or vertical-tail span the longitudinal stability is decreased. Reducing the engine nacelle size increases the static stability of the model. Effective dihedral is essentially zero at 0 deg angle of attack and 0 deg wing incidence

    Alien Registration- Hassell, Margaret Adeline C. (Portland, Cumberland County)

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    https://digitalmaine.com/alien_docs/22047/thumbnail.jp

    Vegetable Crops Report: Variety Trials and Cultural Research Test, Muck Crops Branch, 1985

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    Onion variety trial, 1985 ; Celery variety trial, 1985 ; Broccoli variety trial 1985 ; Row cover evaluation 1985 ; Muskmelons ; Summer squash ; Celery transplants ; Celery seed beds ; Spring broccoli ; Seed quality and seed enhancements on lettuce production 1985 / Richard L. Hassell -- Fertilizer guidelines for vegetable crops grown on muck soils in Ohio / William M. Brooks, E. C. Wittmeyer, and Richard L. Hassel

    Automatically Generating Data Linkages Using a Domain-Independent Candidate Selection Approach

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    Abstract. One challenge for Linked Data is scalably establishing high-quality owl:sameAs links between instances (e.g., people, geographical locations, publications, etc.) in different data sources. Traditional ap-proaches to this entity coreference problem do not scale because they exhaustively compare every pair of instances. In this paper, we pro-pose a candidate selection algorithm for pruning the search space for entity coreference. We select candidate instance pairs by computing a character-level similarity on discriminating literal values that are chosen using domain-independent unsupervised learning. We index the instances on the chosen predicates ’ literal values to efficiently look up similar in-stances. We evaluate our approach on two RDF and three structured datasets. We show that the traditional metrics don’t always accurately reflect the relative benefits of candidate selection, and propose additional metrics. We show that our algorithm frequently outperforms alternatives and is able to process 1 million instances in under one hour on a single Sun Workstation. Furthermore, on the RDF datasets, we show that the entire entity coreference process scales well by applying our technique. Surprisingly, this high recall, low precision filtering mechanism frequently leads to higher F-scores in the overall system

    Amplitude dependent frequency, desynchronization, and stabilization in noisy metapopulation dynamics

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    The enigmatic stability of population oscillations within ecological systems is analyzed. The underlying mechanism is presented in the framework of two interacting species free to migrate between two spatial patches. It is shown that that the combined effects of migration and noise cannot account for the stabilization. The missing ingredient is the dependence of the oscillations' frequency upon their amplitude; with that, noise-induced differences between patches are amplified due to the frequency gradient. Migration among desynchronized regions then stabilizes a "soft" limit cycle in the vicinity of the homogenous manifold. A simple model of diffusively coupled oscillators allows the derivation of quantitative results, like the functional dependence of the desynchronization upon diffusion strength and frequency differences. The oscillations' amplitude is shown to be (almost) noise independent. The results are compared with a numerical integration of the marginally stable Lotka-Volterra equations. An unstable system is extinction-prone for small noise, but stabilizes at larger noise intensity

    Development of a behaviour change intervention: a case study on the practical application of theory

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    BACKGROUND: Use of theory in implementation of complex interventions is widely recommended. A complex trial intervention, to enhance self-management support for people with osteoarthritis (OA) in primary care, needed to be implemented in the Managing Osteoarthritis in Consultations (MOSAICS) trial. One component of the trial intervention was delivery by general practitioners (GPs) of an enhanced consultation for patients with OA. The aim of our case study is to describe the systematic selection and use of theory to develop a behaviour change intervention to implement GP delivery of the enhanced consultation. METHODS: The development of the behaviour change intervention was guided by four theoretical models/frameworks: i) an implementation of change model to guide overall approach, ii) the Theoretical Domains Framework (TDF) to identify relevant determinants of change, iii) a model for the selection of behaviour change techniques to address identified determinants of behaviour change, and iv) the principles of adult learning. Methods and measures to evaluate impact of the behaviour change intervention were identified. RESULTS: The behaviour change intervention presented the GPs with a well-defined proposal for change; addressed seven of the TDF domains (e.g., knowledge, skills, motivation and goals); incorporated ten behaviour change techniques (e.g., information provision, skills rehearsal, persuasive communication); and was delivered in workshops that valued the expertise and professional values of GPs. The workshops used a mixture of interactive and didactic sessions, were facilitated by opinion leaders, and utilised 'context-bound communication skills training.' Methods and measures selected to evaluate the behaviour change intervention included: appraisal of satisfaction with workshops, GP report of intention to practise and an assessment of video-recorded consultations of GPs with patients with OA. CONCLUSIONS: A stepped approach to the development of a behaviour change intervention, with the utilisation of theoretical frameworks to identify determinants of change matched with behaviour change techniques, has enabled a systematic and theory-driven development of an intervention designed to enhance consultations by GPs for patients with OA. The success of the behaviour change intervention in practice will be evaluated in the context of the MOSAICS trial as a whole, and will inform understanding of practice level and patient outcomes in the trial

    Evaluating policy responses to noncommunicable diseases in seven Caribbean countries: challenges to addressing unhealthy diets and physical inactivity

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    This is the final version. Available from the publisher via the DOI in this record.Objective. To identify, assess, and compare existing policies on noncommunicable diseases (NCDs) in the Caribbean, gaps in policy responses, and the factors influencing successful policy development and implementation following the Port of Spain Declaration of 2007. Specifically, to examine policies that target the upstream determinants of two NCD risk factors—unhealthy diets and physical inactivity. Methods. A total of 76 semi-structured interviews with 80 relevant stakeholders in government, the private sector, and civil society were complemented by policy document analysis. Interviews were analyzed pragmatically, framed by the CARICOM government commitments, the WHO NCD Action Plan, a Multiple Streams framework approach, and realist evaluation ideas. Results. The most widely-reported policy successes involved health promotion activities (e.g., school meal programs) that leveraged multisectoral collaboration among government ministries, such as Health, Education, and Agriculture. Large policy gaps still exist around creating legislative, physical, and social environments to support healthy eating and physical activity at the population level. Multisectoral NCD commissions successfully reached across sectors, but had limited influence on policy development. Different policy levels emerged with national-level policies considered a lengthy process, while “On-the-ground” programming was considered faster to implement than national policies. External barriers included a reliance on food imports enabled by international trade agreements limited availability, quality, and affordability of healthy foods. International pushback limited legislation to reduce food imports and the absence of an international/regional framework, similar to the Framework Convention on Tobacco Control, further impedes efforts. Conclusions. Regional collaboration and political support across sectors are essential to accelerating the pace of action to support healthy eating and active living environments. Policy “blueprints” could accelerate the process of development. Regional “NCD champions” could spearhead such responses and approaches.International Development Research Centr
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