5,510 research outputs found

    A probabilistic model of insolation for the Mojave Desert area

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    A discussion of mathematical models of insolation characteristics suitable for use in analysis of solar energy systems is presented and shows why such models are essential for solar energy system design. A model of solar radiation for the Mojave Desert area is presented with probabilistic and deterministic components which reflect the occurrence and density of clouds and haze, and mimic their effects on both direct and indirect radiation. Multiple comparisons were made between measured total energy received per day and the corresponding simulated totals. The simulated totals were all within 11 percent of the measured total. The conclusion is that a useful probabilistic model of solar radiation for the Goldstone, California, area of the Mojave Desert has been constructed

    ALLOCATING BIOSECURITY RESOURCES IN SPACE AND TIME

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    Invasive species can cause significant damage to natural environments, agricultural systems, human populations and the economy as a whole. Biological invasions are complex dynamic systems which are inherently uncertain and their control involves allocation of surveillance and treatment resources in space and time. A complicating factor is that there are at least two types of surveillance: active and passive. Active surveillance, undertaken by pest control agencies, has high sensitivity but generally low coverage because of its high cost. Passive surveillance, undertaken by the public, has low sensitivity and may have high coverage depending on human population density. Its effectiveness depends on the extent to which information campaigns succeed in engaging the public to help locate and report pests. Here we use a spatio-temporal model to study the efficient allocation of search and treatment resources in space and time. In particular we look for complementarities between passive and active surveillance. We identify strategies that increase the probability of eradication and/or decrease the cost of managing an invasion. We also explore ways in which the public can be engaged to achieve cost-effective improvements in the probability of detecting and eradicating a pest.search theory, invasive species, dispersal, passive surveillance., Environmental Economics and Policy,

    Applying search theory to determine the feasibility of eradicating an invasive population in natural environments

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    The detectability of invasive organisms influences the feasibility of eradicating an infestation. Search theory offers a framework for defining and measuring detectability, taking account of searcher ability, biological factors and the search environment. In this paper, search theory concepts are incorporated into a population model, and the costs of search and control are calculated as functions of the amount of search effort (the decision variable). Simulations are performed on a set of weed scenarios in a natural environment, involving different combinations of plant longevity, seed longevity and plant fecundity. Results provide preliminary estimates of the cost and duration of eradication programs to assist in prioritising weeds for control. The analysis shows that the success of an eradication program depends critically on the detectability of the target plant, the effectiveness of the control method, the labour requirements for search and control, and the germination rate of the plant.bioeconomics, invasive species, operations research, population dynamics, weed control, Resource /Energy Economics and Policy,

    William Butler Yeats: An Exhibition

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    This is a catalog of the 1958 exhibition of works from the P. S. 0'Hegarty Collection in the University of Kansas Libraries

    Regulation: A View from Inside the Machine

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    This is a transcript of the keynote address virtually delivered by Hester M. Peirce at the symposium “Protecting the Public While Fostering Innovation and Entrepreneurship: First Principles for Optimal Regulation,” hosted at the University of Missouri School of Law on February 8, 2019. The transcript of this address was initially published on the official website of the Securities and Exchange Commission; it has been lightly edited to ensure readability and formatting continuity

    Weed Search and Control: Theory and Application

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    The detectability of invasive organisms influences the costs and benefits of alternative control strategies, and the feasibility of eradicating an infestation. Search theory offers a mathematically rigorous framework for defining and measuring detectability, taking account of searcher ability, biological factors and the search environment. To demonstrate the application of search theory to invasive species control, invasive species detectability is incorporated into a population simulation model. The model is applied to a base set of parameter values that represent reasonable values for a hypothetical weed. The analysis shows the effects of detectability and search time on the duration of an eradication program. Furthermore, for a given level of detectability and search time, the analysis shows that the variables with the greatest influence on the duration of the eradication effort are search speed, kill efficiency and seed longevity. A series of Monte Carlo simulations are performed on a set of five scenarios, involving different combinations of plant longevity, seed longevity and plant fecundity. Results of these simulations are presented as probability distributions and allow us to calculate how the probability of eradication will be affected by search strategy.search and control, search theory, weed control, stage matrix, impedance factors, population dynamics, stochastic model, Farm Management,
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