3,855 research outputs found

    UNDERSTANDING TECHNOLOGY ADOPTION THROUGH SYSTEM DYNAMICS MODELING: IMPLICATIONS FOR AGRIBUSINESS MANAGEMENT

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    This work demonstrates the utility of sophisticated simulation tools in aiding agribusiness managers' decision making. The system dynamics model developed here provides insight into the use of such models to evaluate potential adoption rates and diffusion patterns of yield mapping and monitoring technologies. The model allows for comparative analyses of the possible effects of different profit assumptions on adoption and diffusion.Agribusiness, Research and Development/Tech Change/Emerging Technologies,

    Abstract Algebra: An Inquiry-Based Approach, Second Edition, Supplemental Material

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    This text is a supplement to Abstract Algebra: An Inquiry-Based Approach, Second Edition. It includes applications of algebra to RSA encryption, check digits, the games of NIM and the 15 Puzzle, and the determination of groups of small order. In addition, reference material that could be useful for some students appears in the appendices, such as background material on functions, methods of proof (including the equivalencies of the Well-Ordering Principle and different versions of mathematical induction), and complex roots of unity. The appendices also contain a complete proof that polynomial rings are rings, a proof of the Fundamental Theorem of Algebra, and a derivation of the formula for solving any cubic equation.https://scholarworks.gvsu.edu/books/1029/thumbnail.jp

    Evaluation of WRF-Sfire Performance with Field Observations from the FireFlux experiment

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    This study uses in-situ measurements collected during the FireFlux field experiment to evaluate and improve the performance of coupled atmosphere-fire model WRF-Sfire. The simulation by WRF-Sfire of the experimental burn shows that WRF-Sfire is capable of providing realistic head fire rate-of-spread and the vertical temperature structure of the fire plume, and, up to 10 m above ground level, fire-induced surface flow and vertical velocities within the plume. The model captured the changes in wind speed and direction before, during, and after fire front passage, along with arrival times of wind speed, temperature, and updraft maximae, at the two instrumented flux towers used in FireFlux. The model overestimated vertical velocities and underestimated horizontal wind speeds measured at tower heights above the 10 m, and it is hypothesized that the limited model resolution over estimated the fire front depth, leading to too high a heat release and, subsequently, too strong an updraft. However, on the whole, WRF-Sfire fire plume behavior is consistent with the interpretation of FireFlux observations. The study suggests optimal experimental pre-planning, design, and execution of future field campaigns that are needed for further coupled atmosphere-fire model development and evaluation

    The SpacePy space science package at 12 years

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    For over a decade, the SpacePy project has contributed open-source solutions for the production and analysis of heliophysics data and simulation results. Here we introduce SpacePy's functionality for the scientific user and present relevant design principles. We examine recent advances and the future of SpacePy in the broader scientific Python ecosystem, concluding with some of the work that has used SpacePy.Comment: 14 pages, 3 figures, accepted for publication in Frontiers in Astronomy and Space Science

    A combined pumping test and heat extraction/recirculation trial in an abandoned haematite ore mine shaft, Egremont, Cumbria, UK

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    A pumping test at rates of up to 50 L sā»Ā¹ was carried out in the 256 m-deep Florence Shaft of the Beckermetā€“Winscalesā€“Florence haematite ore mine in Cumbria, UK, between 8th January and 25th March 2015. Drawdowns in mine water level did not exceed 4 m and the entire interconnected mine complex behaved as a single reservoir. Pumping did, however, induce drawdowns of around 1 m in the St. Bees Sandstone aquifer overlying the Carboniferous Limestone host rock. During a second phase of the pumping test, a proportion of the 11.3ā€“12 Ā°C mine water was directed through a heat pump, which extracted up to 103 kW heat from the water and recirculated it back to the top of the shaft. Provided that an issue with elevated arsenic concentrations (20ā€“30 Āµg Lā»Ā¹) can be resolved, the Florence mine could provide not only a valuable resource of high-quality water for industrial or even potable uses, it could also provide several hundred to several thousand kW of ground sourced heating and/or cooling, if a suitable demand can be identified. The ultimate constraint would be potential hydraulic impacts on the overlying St Bees Sandstone aquifer. The practice of recirculating thermally spent water in the Florence Shaft produced only a rather modest additional thermal benefit

    Determining the significance of associations between two series of discrete events : bootstrap methods /

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    We review and develop techniques to determine associations between series of discrete events. The bootstrap, a nonparametric statistical method, allows the determination of the significance of associations with minimal assumptions about the underlying processes. We find the key requirement for this method: one of the series must be widely spaced in time to guarantee the theoretical applicability of the bootstrap. If this condition is met, the calculated significance passes a reasonableness test. We conclude with some potential future extensions and caveats on the applicability of these methods. The techniques presented have been implemented in a Python-based software toolkit

    Setting Priorities for Space Research: Opportunities and Imperatives

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    This report represents the first phase of a study by a task group convened by the Space Studies Board to ascertain whether it should attempt to develop a methodology for recommending priorities among the various initiatives in space research (that is, scientific activities concerned with phenomena in space or utilizing observations from space). The report argues that such priority statements by the space research community are both necessary and desirable and would contribute to the formulation and implementation of public policy. The report advocates the establishment of priorities to enhance effective management of the nation's scientific research program in space. It argues that scientific objectives and purposes should determine how and under what circumstances scientific research should be done. The report does not take a position on the controversy between advocates of manned space exploration and those who favor the exclusive use of unmanned space vehicles. Nor does the report address questions about the value or appropriateness of Space Station Freedom or proposals to establish a permanent manned Moon base or to undertake a manned mission to Mars. These issues lie beyond the charge to the task group
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