7,320 research outputs found

    A New Approach to Climate Change: A Consideration of Ancillary Benefits in Linking Regional Permit Trading Systems

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    In this paper, I investigate the economic efficiency of two major approaches to greenhouse gas reduction, and evaluate their respective benefits. First, I trace the path of action and thinking on addressing climate change from a global to a regional level. Second, I consider the major economic benefits of having a globally-integrated greenhouse gas abatement system. Third, I consider the economic benefits of regional approaches to climate change, with a focus on the ancillary benefits from greenhouse gas abatement. I conclude by reviewing the challenges to linking regional abatement systems into a cohesive network, and suggest a potential future approach to an economically-efficient abatement of greenhouse gas emissions

    Multiscale Astronomical Image Processing Based on Nonlinear Partial Differential Equations

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    Astronomical applications of recent advances in the field of nonastronomical image processing are presented. These innovative methods, applied to multiscale astronomical images, increase signal-to-noise ratio, do not smear point sources or extended diffuse structures, and are thus a highly useful preliminary step for detection of different features including point sources, smoothing of clumpy data, and removal of contaminants from background maps. We show how the new methods, combined with other algorithms of image processing, unveil fine diffuse structures while at the same time enhance detection of localized objects, thus facilitating interactive morphology studies and paving the way for the automated recognition and classification of different features. We have also developed a new application framework for astronomical image processing that implements some recent advances made in computer vision and modern image processing, along with original algorithms based on nonlinear partial differential equations. The framework enables the user to easily set up and customize an image-processing pipeline interactively; it has various common and new visualization features and provides access to many astronomy data archives. Altogether, the results presented here demonstrate the first implementation of a novel synergistic approach based on integration of image processing, image visualization, and image quality assessment

    Space engine safety system

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    A rocket engine safety system was designed to initiate control procedures to minimize damage to the engine or vehicle or test stand in the event of an engine failure. The features and the implementation issues associated with rocket engine safety systems are discussed, as well as the specific concerns of safety systems applied to a space-based engine and long duration space missions. Examples of safety system features and architectures are given, based on recent safety monitoring investigations conducted for the Space Shuttle Main Engine and for future liquid rocket engines. Also, the general design and implementation process for rocket engine safety systems is presented

    The application of neural networks to the SSME startup transient

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    Feedforward neural networks were used to model three parameters during the Space Shuttle Main Engine startup transient. The three parameters were the main combustion chamber pressure, a controlled parameter, the high pressure oxidizer turbine discharge temperature, a redlined parameter, and the high pressure fuel pump discharge pressure, a failure-indicating performance parameter. Network inputs consisted of time windows of data from engine measurements that correlated highly to the modeled parameter. A standard backpropagation algorithm was used to train the feedforward networks on two nominal firings. Each trained network was validated with four additional nominal firings. For all three parameters, the neural networks were able to accurately predict the data in the validation sets as well as the training set

    Development of a versatile laser light scattering instrument

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    NASA Lewis Research Center is providing and coordinating the technology for placing a compact Laser Light Scattering (LLS) instrument in a microgravity environment. This will be accomplished by defining and assessing user requirements for microgravity experiments, coordinating needed technological developments, and filling technical gaps. This effort is striving to brassboard and evaluate a miniature multi-angle LLS instrument. The progress of the program is reported

    Development of a versatile laser light scattering instrument

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    A versatile laser light scattering (LLS) instrument is developed for use in microgravity to measure microscopic particles of 30 A to above 3 microns. Since it is an optical technique, LLS does not affect the sample being studied. A LLS instrument built from modules allows several configurations, each optimized for a particular experiment. The multiangle LLS instrument can be mounted in the rack in the Space Shuttle and on Space Station Freedom. It is possible that a Space Shuttle glove-box and a lap-top computer containing a correlator card can be used to perform a number of experiments and to demonstrate the technology needed for more elaborate investigations. This offers simple means of flying a great number of experiments without the additional requirements of full-scale flight hardware experiments

    Causes and Implications of the Food Price Surge

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    This paper analyzes the food price surge of 2005 to 2008 in order to better understand the factors causing higher and more volatile food prices during this period, to ascertain the relative importance and possible persistence of the different factors, and to suggest possible implications for future market behavior and policy reactions.Agricultural and Food Policy,

    Labor Market Implications of Rising Costs of Employer-Provided Health Insurance

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    Variation in income tax policies and health insurance costs are shown to be theoretically appropriate instruments to identify endogenous firm wage and benefit offers in a labor supply model. Empirical results show that firms are more likely to provide health insurance benefits in states with high marginal income tax rates and low hospitalization costs. The model implies that over the 1983-1995 period, large increases in health insurance costs and reductions in marginal income tax rates lowered the probability of receiving health insurance benefits from employers by 10 percentage points. This decrease in benefits lowered hours of labor supply by 4-7%.

    PSYX 385.01: Psychology of Personality - Methodology, Theories, and Application

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    PSYX 385.01: Psychology of Personality- Methodology, Theories, and Application

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