8,417 research outputs found

    THE RELATIONSHIP BETWEEN MANAGERIAL HEURISTICS AND ECONOMICS IN PRICING RETAIL MEATS

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    This study develops a theoretical model of the multiproduct firm which allows for imperfect competition in the output market. Hypotheses are tested for retail meat prices concerning the degree and speed of price transmission, the effects of interfirm competition, and the interrelationship between prices within the store. Empirical results indicated that meat prices within a store were highly interrelated. Further, the firm was found to be very responsive to prices of competitors in the short run, but more responsive to wholesale price changes in the long run.Demand and Price Analysis,

    Large wind turbines: A utility option for the generation of electricity

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    The wind resource is such that wind energy generation has the potential to save 6-7 quads of energy nationally. Thus, the Federal Government is sponsoring and encouraging the development of cost effective and reliable wind turbines. One element of the Federal Wind Energy Programs, Large Horizontal Axis Wind Turbine Development, is managed by the NASA Lewis Research Center for the Department of Energy. There are several ongoing wind system development projects oriented primarily toward utility application within this program element. In addition, a comprehensive technology program supporting the wind turbine development projects is being conducted. An overview is presented of the NASA activities with emphasis on application of large wind turbines for generation of electricity by utility systems

    Large wind turbines: A utility option for the generation of electricity

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    The economic and technical potential of wind energy in the United States is discussed. Particular attention is given to the status of wind turbine operational experience as well as the environmental posture of the technology

    Studies on proper simulation during static testing of forward speed effects on fan noise

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    Significant differences exist in the noise generated by engines in flight and engines operating on the test stand. It was observed that these differences can be reduced by the use of an inflow control structure (ICS) in the static test configuration. The results of the third phase of a three phase program are described. The work performed in the first two phases which dealt with the development of a model for atmospheric turbulence, studies of fan noise generated by rotor turbulence interaction, and the development of an inflow control structure design system are summarized. The final phase of the program covers procedures for performing static testing with an ICS projecting the resulting static test data to actual flight test data. Included is a procedures report which covers the design system and techniques for static testing and projecting the static data to flight

    LIMS Instrument Package (LIP) balloon experiment: Nimbus 7 satellite correlative temperature, ozone, water vapor, and nitric acid measurements

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    The Limb Infrared Monitor of the Stratosphere (LIMS) LIP balloon experiment was used to obtain correlative temperature, ozone, water vapor, and nitric acid data at altitudes between 10 and 36 kilometers. The performance of the LIMS sensor flown on the Nimbus 7 Satellite was assessed. The LIP consists of the modified electrochemical concentration cell ozonesonde, the ultraviolet absorption photometric of ozone, the water vapor infrared radiometer sonde, the chemical absorption filter instrument for nitric acid vapor, and the infrared radiometer for nitric acid vapor. The limb instrument package (LIP), its correlative sensors, and the resulting data obtained from an engineering and four correlative flights are described

    Contact area of rough spheres: Large scale simulations and simple scaling laws

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    We use molecular simulations to study the nonadhesive and adhesive atomic-scale contact of rough spheres with radii ranging from nanometers to micrometers over more than ten orders of magnitude in applied normal load. At the lowest loads, the interfacial mechanics is governed by the contact mechanics of the first asperity that touches. The dependence of contact area on normal force becomes linear at intermediate loads and crosses over to Hertzian at the largest loads. By combining theories for the limiting cases of nominally flat rough surfaces and smooth spheres, we provide parameter-free analytical expressions for contact area over the whole range of loads. Our results establish a range of validity for common approximations that neglect curvature or roughness in modeling objects on scales from atomic force microscope tips to ball bearings.Comment: 2 figures + Supporting Materia

    Executive function in first-episode schizophrenia

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    BACKGROUND: We tested the hypothesis that schizophrenia is primarily a frontostriatal disorder by examining executive function in first-episode patients. Previous studies have shown either equal decrements in many cognitive domains or specific deficits in memory. Such studies have grouped test results or have used few executive measures, thus, possibly losing information. We, therefore, measured a range of executive ability with tests known to be sensitive to frontal lobe function. METHODS: Thirty first-episode schizophrenic patients and 30 normal volunteers, matched for age and NART IQ, were tested on computerized test of planning, spatial working memory and attentional set shifting from the Cambridge Automated Neuropsychological Test Battery. Computerized and traditional tests of memory were also administered for comparison. RESULTS: Patients were worse on all tests but the profile was non-uniform. A componential analysis indicated that the patients were characterized by a poor ability to think ahead and organize responses but an intact ability to switch attention and inhibit prepotent responses. Patients also demonstrated poor memory, especially for free recall of a story and associate learning of unrelated word pairs. CONCLUSIONS: In contradistinction to previous studies, schizophrenic patients do have profound executive impairments at the beginning of the illness. However, these concern planning and strategy use rather than attentional set shifting, which is generally unimpaired. Previous findings in more chronic patients, of severe attentional set shifting impairment, suggest that executive cognitive deficits are progressive during the course of schizophrenia. The finding of severe mnemonic impairment at first episode suggests that cognitive deficits are not restricted to one cognitive domain

    Information Ethics Education for a Multicultural World

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    How can we prepare information systems students to face the ethical challenges of a globalized world? This paper describes a three-step approach for addressing these challenges. First, we have designed undergraduate and graduate information ethics courses that expand the range of learning of ethical theories beyond the traditional Western canon to include a wide spectrum of non-Western and feminist theories. Second, we have designed interactive cases for this course that adopt a collaborative learning approach where students work together in small groups by playing different roles that make interdependent decisions. Third, we deliver these cases via an educational simulation, making the approach scalable and transferable to other institutions across the country and around the world. The data for this study includes textual answers from end-of-semester questionnaires completed by 101 undergraduate and graduate students during four information ethics courses that included use of the simulation. Data was analyzed using thematic analysis, focusing on the multicultural and global dimensions of student learning. Five themes emerged from data collected in the four courses: Learning about a Diverse Range of Ethical Theories; Learning about how Ethical Theories are Related to Culture and Values; Relating International and Multicultural Dimensions to Understanding Oneself; Relating International and Multicultural Dimensions to Understanding Others; and Understanding the Role of Ethics and Culture in Information Systems Design and Use. Based on these results, the three-step approach developed in this study can be implemented across the country and around the world to ensure that students are prepared for the ethical challenges of a globalized world

    Exact scaling in the expansion-modification system

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    This work is devoted to the study of the scaling, and the consequent power-law behavior, of the correlation function in a mutation-replication model known as the expansion-modification system. The latter is a biology inspired random substitution model for the genome evolution, which is defined on a binary alphabet and depends on a parameter interpreted as a \emph{mutation probability}. We prove that the time-evolution of this system is such that any initial measure converges towards a unique stationary one exhibiting decay of correlations not slower than a power-law. We then prove, for a significant range of mutation probabilities, that the decay of correlations indeed follows a power-law with scaling exponent smoothly depending on the mutation probability. Finally we put forward an argument which allows us to give a closed expression for the corresponding scaling exponent for all the values of the mutation probability. Such a scaling exponent turns out to be a piecewise smooth function of the parameter.Comment: 22 pages, 2 figure
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