127,934 research outputs found

    Space station models, mockups and simulators

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    Schematic outlines for space station models, mockups, and simulators are presented. The types of Boeing models, mockups, and simulators are given along with the classes and characteristics. The use of models in the 767 program is briefly given. Computerized human factors tools are outlined. The use of computer aided design and computer aided manufacturing in the approach for the space station is advocated

    Logistics hardware and services control system

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    Software system permits onsite direct control of logistics operations, which include spare parts, initial installation, tool control, and repairable parts status and control, through all facets of operations. System integrates logistics actions and controls receipts, issues, loans, repairs, fabrications, and modifications and assets in predicting and allocating logistics parts and services effectively

    Error bounds for compound quadrature of weakly singular integrals

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    Prediction of slow convergence rates for weakly singular numerical quadrature

    Smoothness of solutions of Volterra integral equations with weakly singular kernels

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    Solution smoothness of Volterra integral equations with weakly singular kernel

    The influence of strange quarks on QCD phase diagram and chemical freeze-out: Results from the hadron resonance gas model

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    We confront the lattice results on QCD phase diagram for two and three flavors with the hadron resonance gas model. Taking into account the truncations in the Taylor-expansion of energy density ϵ\epsilon done on the lattice at finite chemical potential μ\mu, we find that the hadron resonance gas model under the condition of constant ϵ\epsilon describes very well the lattice phase diagram. We also calculate the chemical freeze-out curve according to the entropy density ss. The ss-values are taken from lattice QCD simulations with two and three flavors. We find that this condition is excellent in reproducing the experimentally estimated parameters of the chemical freeze-out.Comment: 5 pages, 3 figures and 1 table Talk given at VIIIth international conference on ''Strangeness in Quark Matter'' (SQM 2004), Cape Town, South Africa, Sep. 15-20 200

    Digital curation and the cloud

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    Digital curation involves a wide range of activities, many of which could benefit from cloud deployment to a greater or lesser extent. These range from infrequent, resource-intensive tasks which benefit from the ability to rapidly provision resources to day-to-day collaborative activities which can be facilitated by networked cloud services. Associated benefits are offset by risks such as loss of data or service level, legal and governance incompatibilities and transfer bottlenecks. There is considerable variability across both risks and benefits according to the service and deployment models being adopted and the context in which activities are performed. Some risks, such as legal liabilities, are mitigated by the use of alternative, e.g., private cloud models, but this is typically at the expense of benefits such as resource elasticity and economies of scale. Infrastructure as a Service model may provide a basis on which more specialised software services may be provided. There is considerable work to be done in helping institutions understand the cloud and its associated costs, risks and benefits, and how these compare to their current working methods, in order that the most beneficial uses of cloud technologies may be identified. Specific proposals, echoing recent work coordinated by EPSRC and JISC are the development of advisory, costing and brokering services to facilitate appropriate cloud deployments, the exploration of opportunities for certifying or accrediting cloud preservation providers, and the targeted publicity of outputs from pilot studies to the full range of stakeholders within the curation lifecycle, including data creators and owners, repositories, institutional IT support professionals and senior manager

    PERSISTENT POVERTY ACROSS THE RURAL-URBAN CONTINUUM

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    Persistent poverty is overwhelmingly rural and is very geographically concentrated. We have redefined the USDA ERS persistent poverty classification to include metropolitan counties meeting the 20 percent or higher poor criterion and we extend the time period through the 2000 Census. With this updated definition, there are 382 counties that have had poverty rates of 20 percent or more in each decennial census between 1960 and 2000. These persistent poverty counties are overwhelmingly rural (95 percent) and disproportionately rural (16 percent of nonmetro counties versus 2 percent of metro). The local economic environment in persistent poverty counties is much less favorable than in the nation as a whole. Per capita income is lower and unemployment rates higher in persistent poverty counties. Employment is more concentrated in services, extractive, construction/maintenance, and production/transportation occupations. Residents of persistent poverty counties tend to have lower education levels, and persistent poverty counties generally have larger shares of minority populations. The number of persistent poverty counties reduced considerably during the 1990s, but the "leavers" were disproportionately metropolitan, making persistent poverty increasingly a rural problem. Persistent poverty is overwhelmingly rural and it is very concentrated geographically. In this paper, we examine these striking regularities in U.S. economic geography, seeking to understand the causes and dynamics of poverty across the rural urban continuum. We also consider how alternative characterizations of "persistent poverty" and "rural and urban" might deepen our understanding of poverty and place. The paper has four sections. In the first, we examine how poverty and persistent poverty vary across the Rural Urban Continuum Codes and Urban Influence Codes developed by the USDA Economic Research Service (ERS). We start with the very useful "persistent poverty" classification developed by ERS that defines nonmetropolitan counties as persistent poverty counties if the poverty rate is 20 percent or higher in each decennial census between 1960 and 1990.We redefine persistent poverty to include metropolitan counties meeting the 20 percent or more poor criterion and we extend the time period through the 2000 Census. We also examine where poverty is concentrated in the United States and how persistent poverty varies across the new Core Based Statistical Area definitions for counties, developed recently by the Office of Management and Budget. In the second section, we examine how the demographic characteristics of the population vary across the rural-urban spectrum, comparing persistent poverty county demographics with those of all counties. The third section examines the dynamics of poverty and place. We examine the location, rurality and demographics of counties that escaped persistent poverty statues between 1990 and 2000, and how those characteristics compare to counties that remained in persistent poverty. We then identify the new entrants into high poverty since 1960. In the fourth section, we consider implications of reconceptualizing both "persistent poverty" and "rural and urban diversity". First, we explore the "persistent poverty" county classification, and how alternative definitions of persistent poverty counties might alter the conclusions one reaches about the geography of persistent poverty. We do this by exploring how defining persistent poverty with a different base year such as 1970 or 1980 affects the number of "persistent poverty" counties. We then explore what happens to "persistent poverty" if we raise the poverty threshold to 30 and 40 percent in defining persistent poverty counties. We then examine how conclusions about rural and urban persistent poverty change if one looks at poverty persistence in individual households rather than counties. Using PSID data, this analysis examines rates of persistent household poverty by looking at how the percent of households who remain in poverty for all 5 years during the 1993-98 period varies across central metro county to remote rural county continuum (an aggregation of Beale codes). Finally, we briefly explore how conclusions about the geography of poverty change if one divides metropolitan areas into "central city" and "suburb", and nonmetropolitan areas into "adjacent" and "nonadjacent."Food Security and Poverty,
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