29,239 research outputs found

    Cogeneration computer model assessment: Advanced cogeneration research study

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    Cogeneration computer simulation models to recommend the most desirable models or their components for use by the Southern California Edison Company (SCE) in evaluating potential cogeneration projects was assessed. Existing cogeneration modeling capabilities are described, preferred models are identified, and an approach to the development of a code which will best satisfy SCE requirements is recommended. Five models (CELCAP, COGEN 2, CPA, DEUS, and OASIS) are recommended for further consideration

    Photoheliograph alignment system, November 1967 - June 1968

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    Design and operation of photoheliograph alignment system for use with Apollo telescope moun

    Unified theory of the interplanetary magnetic field

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    Unified theory of interplanetary magnetic fiel

    The Tail of the HI Mass Function

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    The contribution of extragalactic objects with HI masses below 108M10^8 M_\odot to the HI mass function remains uncertain. Several aspects of the detection of low-mass sources in HI surveys are not always considered, and as a result different analysis techniques yield widely different estimates for their number density. It is suggested at one extreme that the number density of galaxies follows a shallow Schechter power-law slope, and at the other extreme that it follows a steep faint-end rise like that found for field optical sources. Here we examine a variety of selection effects, issues of completeness, and consequences of LSS. We derive results for the large Arecibo Dual Beam Survey which indicate that the field mass function does rise steeply, while within the Virgo Cluster environs, the slope appears to be much shallower. Dependence on the local density of galaxies may partially explain differences between surveys.Comment: 8 pages, presented at Mapping the Hidden Universe: The Universe in HI. eds Kraan-Korteweg, Henning, Andernac

    Content and action: The guidance theory of representation

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    The current essay introduces the guidance theory of representation, according to which the content and intentionality of representations can be accounted for in terms of the way they provide guidance for action. We offer a brief account of the biological origins of representation, a formal characterization of the guidance theory, some examples of its use, and show how the guidance theory handles some traditional problem cases for representation: the problems of error and of representation of fictional and abstract entities

    A brief introduction to the guidance theory of representation

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    Recent trends in the philosophy of mind and cognitive science can be fruitfully characterized as part of the ongoing attempt to come to grips with the very idea of homo sapiens--an intelligent, evolved, biological agent--and its signature contribution is the emergence of a philosophical anthropology which, contra Descartes and his thinking thing, instead puts doing at the center of human being. Applying this agency-oriented line of thinking to the problem of representation, this paper introduces the Guidance Theory, according to which the content and intentionality of representations can be accounted for in terms of the way they provide guidance for action. We offer a brief account of the motivation for the theory, and a formal characterization

    The Doppler Spectra of Medium Grazing Angle Sea Clutter; Part 1: Characterisation

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    This paper is concerned with the characterisation of Doppler spectra from high range resolution X-band radar sea clutter observed from an airborne platform over the range of grazing angles, 15° to 45°. It is observed that when looking up or down wind there is a strong correlation between mean Doppler shift and local spectrum intensity. When combined with random fluctuations of spectrum width, these characteristics give the spectra a temporal and spatial variability. This behaviour has previously been observed in low grazing angle data and these results confirm the wider applicability of the models developed using that data. The modelling method is also extended here to capture the bimodal behaviour observed with high intensity returns from breaking waves looking up or down-wind

    A comparative assessment of solar thermal electric power plants in the 1-10 MWe range

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    The candidate power system technologies were ranked in terms of the cost of electric energy each system produces. In all cases, it was assumed that development programs would result in mature power plant systems that could be commercially manufactured. The results of the study, a brief description of the systems examined, and the methodologies used are presented
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