1,076 research outputs found

    Emerging from the MIST: A Connector Tool for Supporting Programming by Non-programmers

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    Software development is an iterative process. As user re-quirements emerge software applications must be extended to support the new requirements. Typically, a programmer will add new code to an existing code base of an application to provide a new functionality. Previous research has shown that such extensions are easier when application logic is clearly separated from the user interface logic. Assuming that a programmer is already familiar with the existing code base, the task of writing the new code can be considered to be split into two sub-tasks: writing code for the application logic; that is, the actual functionality of the application; and writing code for the user interface that will expose the functionality to the end user. The goal of this research is to reduce the effort required to create a user interface once the application logic has been created, toward supporting scientists with minimal pro-gramming knowledge to be able to create and modify pro-grams. Using a Model View Controller based architecture, various model components which contain the application logic can be built and extended. The process of creating and extending the views (user interfaces) on these model components is simplified through the use of our Malleable Interactive Software Toolkit (MIST), a tool set an infrastructure intended to simplify the design and extension of dynamically reconfigurable interfaces. This paper focuses on one tool in the MIST suite, a connec-tor tool that enables the programmer to evolve the user interface as the application logic evolves by connecting related pieces of code together; either through simple drag-and-drop interactions or through the authoring of Python code. The connector tool exemplifies the types of tools in the MIST suite, which we expect will encourage collabora-tive development of applications by allowing users to inte-grate various components and minimizing the cost of de-veloping new user interfaces for the combined compo-nents

    Scientists in the MIST: Simplifying Interface Design for End Users

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    We are building a Malleable Interactive Software Toolkit (MIST), a tool set and infrastructure to simplify the design and construction of dynamically-reconfigurable (malleable) interactive software. Malleable software offers the end-user powerful tools to reshape their interactive environment on the fly. We aim to make the construction of such software straightforward, and to make reconfiguration of the resulting systems approachable and manageable to an educated, but non-specialist, user. To do so, we draw on a diverse body of existing research on alternative approaches to user interface (UI) and interactive software construction, including declarative UI languages, constraint-based programming and UI management, reflection and data-driven programming, and visual programming techniques

    Spectroscopy of a fractional Josephson vortex molecule

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    In long Josephson junctions with multiple discontinuities of the Josephson phase, fractional vortex molecules are spontaneously formed. At each discontinuity point a fractional Josephson vortex carrying a magnetic flux Φ<Φ0|\Phi|<\Phi_0, Φ02.07×1015\Phi_0\approx 2.07\times 10^{-15} Wb being the magnetic flux quantum, is pinned. Each vortex has an oscillatory eigenmode with a frequency that depends on Φ/Φ0\Phi/\Phi_0 and lies inside the plasma gap. We experimentally investigate the dependence of the eigenfrequencies of a two-vortex molecule on the distance between the vortices, on their topological charge =2πΦ/Φ0\wp=2\pi\Phi/\Phi_0 and on the bias current γ\gamma applied to the Josephson junction. We find that with decreasing distance between vortices, a splitting of the eigenfrequencies occurs, that corresponds to the emergence of collective oscillatory modes of both vortices. We use a resonant microwave spectroscopy technique and find good agreement between experimental results and theoretical predictions.Comment: submitted to Phys. Rev.

    Where’s the risk? Landscape epidemiology of gastrointestinal parasitism in Alberta beef cattle

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    Sherpa Romeo green journal; open accessBackground: Gastrointenstinal nematodes (GIN) present a serious challenge to the health and productivity of grazing stock around the globe. However, the epidemiology of GIN transmission remains poorly understood in northern climates. Combining use of serological diagnostics, GIS mapping technology, and geospatial statistics, we evaluated ecological covariates of spatial and temporal variability in GIN transmission among bovine calves pastured in Alberta, Canada. Methods: Sera were collected from 1000 beef calves across Alberta, Canada over three consecutive years (2008–2010) and analyzed for presence of anti-GIN antibodies using the SVANOVIR Ostertagia osteragi-Ab ELISA kit. Using a GIS and Bayesian multivariate spatial statistics, we evaluated the degree to which variation in specific environmental covariates (e.g. moisture, humidity, temperature) was associated with variation in spatial and temporal heterogeneity in exposure to GIN (Nematodirus and other trichostrongyles, primarily Ostertagia and Cooperia). Results: Variation in growing degree days above a base temperature of 5 °C, humidity, air temperature, and accumulated precipitation were found to be significant predictors of broad–scale spatial and temporal variation in serum antibody concentrations. Risk model projections identified that while transmission in cattle from southeastern and northwestern Alberta was relatively low in all years, rate of GIN transmission was generally higher in the central region of Alberta. Conclusions: The spatial variability in risk is attributed to higher average humidity, precipitation and moderate temperatures in the central region of Alberta in comparison with the hot, dry southeastern corner of the province and the cool, dry northwestern corner. Although more targeted sampling is needed to improve model accuracy, our projections represent an important step towards tying treatment recommendations to actual risk of infection.Ye

    Classical Cepheid Pulsation Models: IX. New Input Physics

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    We constructed several sequences of classical Cepheid envelope models at solar chemical composition (Y=0.28,Z=0.02Y=0.28, Z=0.02) to investigate the dependence of the pulsation properties predicted by linear and nonlinear hydrodynamical models on input physics. To study the dependence on the equation of state (EOS) we performed several numerical experiments by using the simplified analytical EOS originally developed by Stellingwerf and the recent analytical EOS developed by Irwin. Current findings suggest that the pulsation amplitudes as well as the topology of the instability strip marginally depend on the adopted EOS. We also investigated the dependence of observables predicted by theoretical models on the mass-luminosity (ML) relation and on the spatial resolution across the Hydrogen and the Helium partial ionization regions. We found that nonlinear models are marginally affected by these physical and numerical assumptions. In particular, the difference between new and old models in the location as well as in the temperature width of the instability strip is on average smaller than 200 K. However, the spatial resolution somehow affects the pulsation properties. The new fine models predict a period at the center of the Hertzsprung Progression (PHP=9.65P_{HP}=9.65-9.84 days) that reasonably agree with empirical data based on light curves (PHP=10.0±0.5P_{HP}=10.0\pm 0.5 days; \citealt{mbm92}) and on radial velocity curves (PHP=9.95±0.05P_{HP}=9.95\pm 0.05 days; \citealt{mall00}), and improve previous predictions by Bono, Castellani, and Marconi (2000, hereinafter BCM00).Comment: 35 pages, 7 figures. Accepted for publication in the Astrophysical Journa

    Thermal escape of fractional vortices in long Josephson junctions

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    We consider a fractional Josephson vortex in a long 0-kappa Josephson junction. A uniformly applied bias current exerts a Lorentz force on the vortex. If the bias current exceeds the critical current, an integer fluxon is torn off the kappa-vortex and the junction switches to the voltage state. In the presence of thermal fluctuations the escape process takes place with finite probability already at subcritical values of the bias current. We experimentally investigate the thermally induced escape of a fractional vortex by high resolution measurements of the critical current as a function of the topological charge kappa of the vortex and compare the results to numerical simulations for finite junction lengths and to theoretical predictions for infinite junction lengths. To study the effect caused by the junction geometry we compare the vortex escape in annular and linear junctions.Comment: submitted to PR

    Evaluation of frameworks of analysis employed in studies of exclusion zones

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    The purpose of this Work Package is to examine the various approaches to analysing fishery exclusion zones (FEZs) and to identify the circumstances in which one approach might be preferred to another. Our concern here is not so much with answering questions about exclusion zones - these being dealt with in later Work Packages - as with articulating the questions themselves and in understanding how in principle they could be addressed. An important theme is the precision with which questions need to be answered, since this will determine the type of information collected and how such information is analysed. The question ' is an exclusion zone likely to improve the condition of this fishery ?' is less precise and less demanding of data than the question ' by how much will an exclusion zone improve this fishery ?' since it could in principle be answered by expert judgement rather than quantitative analysis. In practice fisheries managers may be confronted with situations where decisions have to be made quickly, and qualitative answers may be the only thing possible in circumstances where data cannot be obtained in the available time. The Work Package will look at FEZs from a number of different perspectives, but its dominant concern is with the information – principally in the form of socio-economic and biological indicators - needed by fisheries managers in order to evaluate the effectiveness of FEZs. To contextualise the discussion we start by outlining a paradigm for understanding the linkages between human activities and the environment, showing how it can be applied to fisheries and marine resources. The Work Package then considers the substantive information requirements of fisheries managers, commencing with socio-economic assessment and moving on to a review of biological assessment and the progress which has been made in the development of mathematical models of FEZs. Bio-economic modelling, which is essentially a specialised type of socio-economic assessment in which explicit account is taken of the interaction between the biological and economic components of the fishing system, is dealt with in the final section
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