9,314 research outputs found

    World Community: Searching for a Global Cosmology

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    Every culture in history has had a cosmology, a myth about origins. Such cosmologies provide societal and religious structure, ethics, and morals. Driven by mass communication, humanity is rapidly moving toward a world community. Individual cultures have been increasingly thrown into conflict, causing fear and defensive reactions. Global humanity needs what no culture has ever been without: a unifying cosmology. Many who are seeking fruitful dialogue between faith and science have become intimately involved in searching for such a cosmology. In the same spirit, others seek a more productive interfaith dialogue. Complex-systems approaches and process thinking may provide a model for both

    Guidance, navigation, and control subsystem equipment selection algorithm using expert system methods

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    Enhanced engineering tools can be obtained through the integration of expert system methodologies and existing design software. The application of these methodologies to the spacecraft design and cost model (SDCM) software provides an improved technique for the selection of hardware for unmanned spacecraft subsystem design. The knowledge engineering system (KES) expert system development tool was used to implement a smarter equipment section algorithm than that which is currently achievable through the use of a standard data base system. The guidance, navigation, and control subsystems of the SDCM software was chosen as the initial subsystem for implementation. The portions of the SDCM code which compute the selection criteria and constraints remain intact, and the expert system equipment selection algorithm is embedded within this existing code. The architecture of this new methodology is described and its implementation is reported. The project background and a brief overview of the expert system is described, and once the details of the design are characterized, an example of its implementation is demonstrated

    Automated assembly of large space structures using an expert system executive

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    NASA LaRC has developed a unique testbed for investigating the practical problems associated with the assembly of large space structures using robotic manipulators. The testbed is an interdisciplinary effort which considers the full spectrum of assembly problems from the design of mechanisms to the development of software. This paper will describe the automated structures assembly testbed and its operation, detail the expert system executive and its development, and discuss the planned system evolution. Emphasis will be placed on the expert system development of the program executive. The executive program must be capable of directing and reliably performing complex assembly tasks with the flexibility to recover from realistic system errors. By employing an expert system, information pertaining to the operation of the system was encapsulated concisely within a knowledge base. This lead to a substantial reduction in code, increased flexibility, eased software upgrades, and realized a savings in software maintenance costs

    Open market operations in the 1990s

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    Open market operations--the purchase and sale of Treasury and federal agency securities--are the Federal Reserve's principal tool for implementing monetary policy. The objectives and conduct of open market operations have continued to evolve in the 1990s, partly in response to the way the Federal Open Market Committee implements monetary policy and explains it to the public. Also shaping operations have been changes in financial markets, including developments in the market for repurchase agreements and declines in the balances that depository institutions must hold at the Federal Reserve.Federal Open Market Committee ; Open market operations

    Manufacturing Dendritic Cells for Immunotherapy: Monocyte Enrichment

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    Dendritic cells play a key role in activation of the immune system as potent antigen-presenting cells. This pivotal position, along with the ability to generate dendritic cells from monocytes and ready uptake of antigen, makes them an intriguing vehicle for immunotherapy for a variety of indications. Since the first reported trial using dendritic cells in 1995, they have been used in trials all over the world for a plethora of indications. Monocyte-derived dendritic cells are generated from whole blood or apheresis products by culturing enriched monocytes in the presence of interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF). A variety of methods can be used for enrichment of monocytes for generation of clinical-grade dendritic cells and are summarized herein

    Suited for spacewalking: A teacher's guide with activities

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    This publication is an activity guide for teachers on spacesuits and spacewalking. It uses the intensive interest many children have in space exploration as a launching point for hands-on-opportunities. The guide begins with brief discussions of the space environment, the history of space walking, the Space Shuttle spacesuit, and working in space. These are followed by a series of activities that enable children to explore the space environment as well as the science and technology behind the functions of spacesuits. The activities are not rated for specific grade levels because they can be adapted for students of many ages. The guide concludes with a brief glossary as well as references and resources

    An Examination of Student Performance in Pre-Requisite Coursework and Upper Division Nursing Coursework

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    Admission and retention of qualified nursing students are essential in meeting the demands of a rapidly changing health care environment and nursing shortage. The purpose of this exploratory correlational study was to determine the relationship between student performance in quantitative pre-requisite coursework and student performance in upper division nursing coursework in order to identify students at-risk for attrition. A series of descriptive and correlational analyses were conducted using pre-existing institutional data. A moderate relationship existed among the chemistry II and first-year upper division nursing courses (r = .21 to r = .40). These results suggest that prerequisite chemistry course performance could be a reliable predictor of academic success

    Ichthyofaunal Diversification and Distribution in Jane\u27s Creek Watershed, Randolph County, Arkansas

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    The purposes of this study were to determine the qualitative and quantitative distribution of fishes in the Jane\u27s Creek watershed. Jane\u27s Creek is a clear, spring-fed Ozark stream in northeastern Arkansas. A knowledge of the ichthyofauna of this stream prior to a long-range impoundment is of significance to the natural history of Arkansas. Jane\u27s Creek and its tributaries were found to be alkaline, with no measurable turbidity, and to have low levels of carbon dioxide. Dissolved oxygen values ranged from 6.1 to 16.0 ppm. Only slight differences in physicochemical conditions were noted among stations and between pool and riffle areas at each station. A total of 52 species of fishes were collected during this study. Most fishes were collected by seining. A rotenone sample on 10 July 1972 yielded a standing crop of 3,005 specimens and 392 kg/ha (2,681 specimens and 349 lb/A),minnows and darters excluded. Except for black-spot disease (Apophallus sp.) on some cyprinids, the fishes generally appeared robust. The large number of fish species collected during the sampling period reflected the diversity of habitats available. These observations indicated a healthy ichthyofaunal population inhabiting a stream system receiving little if any pollution
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