36,316 research outputs found

    The Risk Premium for Equity: Explanations and Implications

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    The equity premium puzzle shows that using standard parameters and setup, the Consumption-based Capital Asset Pricing Model's (CCAPM's) prediction of the premium associated with systematic risk is out by an order of magnitude.The object of this paper is to consider the implications of each of the broad classes of explanations of the equity premium puzzle for resource allocation, welfare and policy.We argue that the most robust implications are those that flow directly from the high price of systematic risk and are therefore independent of the resolution of the puzzle.risk premium;equity capital;resource allocation;welfare;capital asset pricing

    Understanding the local livelihood system in reosurce management: the pelagic longline fishery in Gouyaye, Grenada

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    ABSTRACT There is a need to include social objectives in fisheries management, and this paper focuses on one set of social considerations, those regarding livelihood. We pay particular attention to sustainable livelihood strategies, the importance of commercial pelagic longline fishing for the entire community livelihood system, and implications for management. Field data were obtained between December 2002 and March 2004 in Gouyave, Grenada, using participant observation, semi-structured interviews, and a quantitative survey. The economic base (fishing and agriculture) of the community is both unpredictable and seasonal, therefore individuals and households engage in diverse strategies to secure their livelihood. Three livelihood strategies were deemed important: 1) livelihood diversification, developing additional sources of income from agriculture, wage labor, and trade work, 2) fishing diversification, learning to switch to alternative gear and species, and 3) the availability of an informal "social security net" involving cash and in-kind assistance. These strategies help to spread the flow of income and food during lean times and across seasons. A major management implication is that fishery managers need to pay attention to the multi-species nature of fisheries and to the importance of livelihood diversification, including reliance on other economic sectors. RESUMEN Existe la necesidad de incluir objetivos sociales en el manejo de la industria pesquera y este artículo se focaliza en un grupo de consideraciones sociales, las que se refieren al sustento. Prestanos particular atención a las estrategias de los sustento sostenibles, la importancia de la pesca pelágica comercial para el sustento de toda la comunida y las implicaciones para su manejo. Los datos de campo fueron obtenidos entre Diciembre del 2002 y Marzo del 2004 de Gouyave, Grenada a través del estudio de los participantes, entrevistas semi-estructuradas y un examen cuantitativo. La base económica (pesca y agricultura) de la comunidad es tanto impredecible como variable, por lo tanto individuos y hogares adoptan estrategias diversificadas para logar la seguridad del sustento. Tres estrategias de sustento fueron consideradas importantes: 1) diversificación de las actividades para sustento desarrollando fuentes de ingresos adicionales en agricultura, labor pagada y trabajo de obrero, 2) la diversificación de la pesca aprendiendo a utilizar hacia equipos y especies alternativas, y 3) la disponibilidad de una red de seguridad social que incluye asistencia monetaria y en especie. Estas estrategias diversificadas ayudan a distribuir el flujo de ingresos y alimentos a través de las estaciones. Un mayor involvcramiento en el manejo implica que los gerentes pesqueros presten mayor cuidado a la naturaleza multi-especies de la pesca y a la importancia de la diversificacion del sustento, incluyendo la confianza en otros sectores económicos

    Proposed methods for reviewing the outcomes of health research: the impact of funding by the UK's Arthritis Research Campaign

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    Background: External and internal factors are increasingly encouraging research funding bodies to demonstrate the outcomes of their research. Traditional methods of assessing research are still important, but can be merged into broader multi-dimensional categorisations of research benefits. The onus has hitherto been on public sector funding bodies, but in the UK the role of medical charities in funding research is particularly important and the Arthritis Research Campaign, the leading medical charity in its field in the UK, commissioned a study to identify the outcomes from research that it funds. This article describes the methods to be used. Methods: A case study approach will enable narratives to be told, illuminating how research funded in the early 1990s was (or was not) translated into practice. Each study will be organised using a common structure, which, with careful selection of cases, should enable cross-case analysis to illustrate the strengths of different modes and categories of research. Three main interdependent methods will be used: documentary and literature review; semi-structured interviews; and bibliometric analysis. The evaluative framework for organising the studies was previously used for assessing the benefits from health services research. Here, it has been specifically amended for a medical charity that funds a wide range of research and is concerned to develop the careers of researchers. It was further refined in three pilot studies. The framework has two main elements. First, a multi-dimensional categorisation of benefits going from the knowledge produced in peer reviewed journal articles through to the health and potential economic gain. The second element is a logic model, which, with various stages, should provide a way of organising the studies. The stock of knowledge is important: much research, especially basic, will feed into it and influence further research rather than directly lead to health gains. The cross-case analysis will look for factors associated with outcomes. Conclusions: The pilots confirmed the applicability of the methods for a full study which should assist the Arthritis Research Campaign to demonstrate the outcomes from its funding, and provide it with evidence to inform its own policies

    A manipulator arm for zero-g simulations

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    A 12-ft counterbalanced Slave Manipulator Arm (SMA) was designed and fabricated to be used for resolving the questions of operational applications, capabilities, and limitations for such remote manned systems as the Payload Deployment and Retrieval Mechanism (PDRM) for the shuttle, the Free-Flying Teleoperator System, the Advanced Space Tug, and Planetary Rovers. As a developmental tool for the shuttle manipulator system (or PDRM), the SMA represents an approximate one-quarter scale working model for simulating and demonstrating payload handling, docking assistance, and satellite servicing. For the Free-Flying Teleoperator System and the Advanced Tug, the SMA provides a near full-scale developmental tool for satellite servicing, docking, and deployment/retrieval procedures, techniques, and support equipment requirements. For the Planetary Rovers, it provides an oversize developmental tool for sample handling and soil mechanics investigations. The design of the SMA was based on concepts developed for a 40-ft NASA technology arm to be used for zero-g shuttle manipulator simulations

    Planet formation around stars of various masses: Hot super-Earths

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    We consider trends resulting from two formation mechanisms for short-period super-Earths: planet-planet scattering and migration. We model scenarios where these planets originate near the snow line in ``cold finger'' circumstellar disks. Low-mass planet-planet scattering excites planets to low periastron orbits only for lower mass stars. With long circularisation times, these planets reside on long-period eccentric orbits. Closer formation regions mean planets that reach short-period orbits by migration are most common around low-mass stars. Above ~1 Solar mass, planets massive enough to migrate to close-in orbits before the gas disk dissipates are above the critical mass for gas giant formation. Thus, there is an upper stellar mass limit for short-period super-Earths that form by migration. If disk masses are distributed as a power law, planet frequency increases with metallicity because most disks have low masses. For disk masses distributed around a relatively high mass, planet frequency decreases with increasing metallicity. As icy planets migrate, they shepherd interior objects toward the star, which grow to ~1 Earth mass. In contrast to icy migrators, surviving shepherded planets are rocky. Upon reaching short-period orbits, planets are subject to evaporation processes. The closest planets may be reduced to rocky or icy cores. Low-mass stars have lower EUV luminosities, so the level of evaporation decreases with decreasing stellar mass.Comment: Accepted to ApJ. 13 pages of emulateap

    Thin film temperature sensor

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    Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed
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