1,913 research outputs found

    NASA TLA workload analysis support. Volume 1: Detailed task scenarios for general aviation and metering and spacing studies

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    The techniques required to produce and validate six detailed task timeline scenarios for crew workload studies are described. Specific emphasis is given to: general aviation single pilot instrument flight rules operations in a high density traffic area; fixed path metering and spacing operations; and comparative workload operation between the forward and aft-flight decks of the NASA terminal control vehicle. The validation efforts also provide a cursory examination of the resultant demand workload based on the operating procedures depicted in the detailed task scenarios

    State promotion of local public goods: The case of public libraries, 1880-1929

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    The public library movement of the late nineteenth and early twentieth centuries led to a significant expansion of library services across the United States. We study the impact of state-level institutional development on the creation of local public goods. State library commissions were modestly funded state entities charged with helping localities establish libraries. State library associations were voluntary organizations with a similar mission, having as members the librarians of existing public libraries. Library-enabling legislation clarified the legality and taxation possibilities for local government entities such as towns, municipalities and counties to support libraries. Employing panel data drawn from a series of detailed reports on public libraries conducted by the U.S. Bureau of Education, we use a difference-in-differences methodology to identify the impact of commissions, associations, and enabling legislation on library development in matched pairs of counties that straddle state borders. Our results suggest that state-level institutions and legislation had a statistically and economically significant effect on public library development. The finding has implications for future interpretations of the history of the United States as a “nation of joiners”; local civic engagement and associational life was importantly influenced by larger scale civic and political action. JEL classifications: H40, H75, N31, N32, N41, N4

    Public libraries and political participation, 1870-1940

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    The public library movement of the late 19th and early 20th centuries fostered a rapid increase in the number and quality of public libraries in cities and towns across the United States. One important argument for libraries was that they would enhance American democracy by promoting virtues of citizenship and enabling access to information. This paper examines how voter turnout was affected, in the short-term, by the establishment of public libraries, using a county-by-election year panel. Our empirical strategy exploits the founding dates of public libraries as discrete events that should have influenced subsequent voting behavior. Over the wide range of specifications considered, the vast majority of regression results suggest that libraries had no significant short term impact on voter turnout. We discuss potential reasons for this finding, and compare it with recent work finding a positive impact of newspapers on political participation. JEL classifications: H40, H75, N31, N32, N41, N4

    On-line diagnosis of unrestricted faults

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    A formal model for the study of on-line diagnosis is introduced and used to investigate the diagnosis of unrestricted faults. A fault of a system S is considered to be a transformation of S into another system S' at some time tau. The resulting faulty system is taken to be the system which looks like S up to time tau, and like S' thereafter. Notions of fault tolerance error are defined in terms of the resulting system being able to mimic some desired behavior as specified by a system similar to S. A notion of on-line diagnosis is formulated which involves an external detector and a maximum time delay within which every error caused by a fault in a prescribed set must be detected. It is shown that if a system is on-line diagnosable for the unrestricted set of faults then the detector is at least as complex, in terms of state set size, as the specification. The use of inverse systems for the diagnosis of unrestricted faults is considered. A partial characterization of those inverses which can be used for unrestricted fault diagnosis is obtained

    Public relations among Christian, multi-national, non-profit organizations in Europe

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    Title from PDF of title page (University of Missouri--Columbia, viewed on September 18, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisor: Dr. Fritz CroppIncludes bibliographical references.Vita.M.A. University of Missouri--Columbia 2012."May 2012"Public relations as a profession has existed in Europe for more than a century, yet most current practice and teaching is based on the American model. To address this situation, in 1998 the European Association of Public Relations Education and Research (CERP) launched a task force to begin work on a European Public Relations Body of Knowledge (EBOK). The current research reviews literature related to European public relations, then investigates the public-relations efforts of European branches of three global Christian non-profit organizations, using a qualitative approach. Its purpose is to discern how the principles and practices of the organizations align with the EBOK findings, and draw conclusions that may guide future practice. It became apparent that the roles of public-relations practitioners in the Christian, non-profit world in Europe falls within the Managerial Dimension of the EBOK parameters. Management's expectations fell within the same dimension. Furthermore, respondents seemed to embrace a one-way communication model simultaneously with the two-way asymmetrical model. These findings are unexpected, since the EBOK study suggests that the Reflective or Educational dimensions should be most important, and Grunig holds that the two-way symmetrical model represents the pinnacle of excellence in public relations. Conclusions are drawn as to what these findings represent

    On-line diagnosis of sequential systems, 2

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    The theory and techniques applicable to the on-line diagnosis of sequential systems, were investigated. A complete model for the study of on-line diagnosis is developed. First an appropriate class of system models is formulated which can serve as a basis for a theoretical study of on-line diagnosis. Then notions of realization, fault, fault-tolerance and diagnosability are formalized which have meaningful interpretations in the the context of on-line diagnosis. The diagnosis of systems which are structurally decomposed and are represented as a network of smaller systems is studied. The fault set considered is the set of faults which only affect one component system is the network. A characterization of those networks which can be diagnosed using a purely combinational detector is achieved. A technique is given which can be used to realize any network by a network which is diagnosable in the above sense. Limits are found on the amount of redundancy involved in any such technique

    The GSFC Mark-2 three band hand-held radiometer

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    A self-contained, portable, hand-radiometer designed for field usage was constructed and tested. The device, consisting of a hand-held probe containing three sensors and a strap supported electronic module, weighs 4 1/2 kilograms. It is powered by flashlight and transistor radio batteries, utilizes two silicon and one lead sulfide detectors, has three liquid crystal displays, sample and hold radiometric sampling, and its spectral configuration corresponds to LANDSAT-D's thematic mapper bands. The device was designed to support thematic mapper ground-truth data collection efforts and to facilitate 'in situ' ground-based remote sensing studies of natural materials. Prototype instruments were extensively tested under laboratory and field conditions with excellent results

    NASA TLA workload analysis support. Volume 3: FFD autopilot scenario validation data

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    The data used to validate a seven time line analysis of forward flight deck autopilot mode for the pilot and copilot for NASA B737 terminal configured vehicle are presented. Demand workloads are given in two forms: workload histograms and workload summaries (bar graphs). A report showing task length and task interaction is also presented

    NASA TLA workload analysis support. Volume 2: Metering and spacing studies validation data

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    Four sets of graphic reports--one for each of the metering and spacing scenarios--are presented. The complete data file from which the reports were generated is also given. The data was used to validate the detail task of both the pilot and copilot for four metering and spacing scenarios. The output presents two measures of demand workload and a report showing task length and task interaction

    Resilience of Working Agricultural Landscapes

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    Many alternative agricultural approaches have been developed as a response to the social and ecological costs of modern industrialized agriculture. These include diversified, organic, sustainably intensified, and ecologically intensified farming systems, each of which addresses different aspects of agriculture as a social-ecological system. However, clear theoretical models that account for human-nature coupling and the importance of scale are lacking. Global change, including climate change, land use change, and other human activities influencing social-ecological systems, is exacerbating uncertainty regarding agriculture system dynamics and increasing the need for comprehensive models that include a dynamical integration of socio-ecological-economic influences. Resilience theory and related ideas such as panarchy have begun to actively inform agricultural science and practice in ways that should help enable current agricultural practices to become more sustainable – and resilient. However, there are several key resilience concepts that have yet to be fully developed within the agricultural research community. In this chapter, we briefly present resilience and its relevance to agriculture, and then we focus on three interrelated resilience ideas that have received less attention in the agriculture literature: (1) the functional attributes which underpin resilience; (2) the possibility of alternative regimes in agricultural systems and the implications for both continued agricultural production and the ecological landscapes in which agricultural systems are embedded; and (3) the relevance of scale for understanding and managing complex agricultural systems. We finish by discussing a path forward for the continued development of theories that can adequately encompass the full complexity of agricultural systems
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