9,607 research outputs found

    Implementing a real time reasoning system for robust diagnosis

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    The objective of the Thermal Control System Automation Project (TCSAP) is to develop an advanced fault detection, isolation, and recovery (FDIR) capability for use on the Space Station Freedom (SSF) External Active Thermal Control System (EATCS). Real-time monitoring, control, and diagnosis of the EATCS will be performed with a knowledge based system (KBS). Implementation issues for the current version of the KBS are discussed

    Mission safety evaluation report for STS-37, postflight edition

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    STS-37/Atlantis was launched on April 5, 1991 from Kennedy Space Center launch complex 39B at 9:23 a.m. Eastern Standard Time (EST). Launch was delayed 4 minutes 45 seconds because of safety concerns about the low cloud ceiling and the wind direction in the potential blast area. Based on the limited number and type of inflight anomalies encountered, the Space Shuttle operated satisfactorily throughout the STS-37 mission. A contingency EVA was performed by the crew on Flight Day (FD) 3 to free a sticky Gamma Ray Observatory (GRO) high gain antenna, after which the GRO primary payload was successfully deployed by the Orbiter's Remote Manipulator System. The GRO, which weighed just over 35,000 lbs, was the heaviest NASA science satellite ever deployed by the Space Shuttle into low Earth orbit. The scheduled entry/landing on FD 6 was waved off for one day due to high wind conditions at Edwards Air Force Base. Atlantis landed on FD 7, 11 April 1991 on Edwards AFB lakebed runway 33 at 9:55 a.m. Eastern Daylight Time

    A Functional Ecological Comparison of three Sponge Species from the Lower Florida Keys

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    The shallow, tidal flats off the islands of the lower Florida Keys represent a harsh environment for sessile marine invertebrates. This habitat is home to three taxonomically distinct sponge species that share similar rope morphologies: Cliona varians forma varians, Ircinia variabilis, and Neopetrosia subtriangularis. Despite sharing a habitat, these three species differ in their symbiont regime, with C. varians hosting dinoflagellate photosymbionts, and I. variabilis and N. subtriangularis hosting cyanobacterial photosymbionts. We conducted experiments to measure other ecological differences between these species. The sponges were all assayed for pumping rates using dye-video analysis and tissue samples were taken to compare the composition and functional genes of their microbiomes. The results indicated that N. subtriangularis had a significantly higher pumping rate than the other species. The microbiomes of the species varied, and the microbiome functional gene screening provided evidence that C. varians forma varians hosts nitrogen fixing bacteria, that I. variabilis hosts methane metabolizing bacteria, and that N. subtriangularis hosts nitric oxide reducing bacteria. More work is currently underway to examine the metabolism of these sponges, giving us insight into the unique ecology of this harsh habitat

    Credit Line Availability and Utilization in REITs

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    Analysis of REIT credit line availability and use under normal conditions and during the recent financial crisis are provided. Descriptive statistics indicate REIT credit lines represent an important component of capital structure, credit line availability and utilization have increased substantially over the sample period, and REITs maintain precautionary liquidity via credit lines rather than holding cash. Multivariate results indicate that credit line availability is directly associated with cash flow uncertainty, dividend distributions, acquisitions, and capital market access and is inversely linked to the market-to-book ratio. Credit line use is unrelated to cash flow volatility and dividends, but is correlated with operating cash flow, acquisitions, and capital market access. Unlike with non-REITs, when setting credit limits lenders focus on dividends and not just operating cash flow. Despite finding that line availability is influenced by dividend payments, REITs do not systematically use lines to pay dividends implying that dividends are paid from operating cash flows.

    The Post-Black Aesthetic and Meanings of Blackness through the Collage Narratives of Kara Walker and Fred Wilson

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    The 1990s spawned a new generation of African-American artists who worked to understand and deconstruct meanings of blackness within the context of the post-black aesthetic. Their conceptualized installations resulted in various discourses on the nature of race, culture and identity within the framework of exhibition and collection. Considered \u27post-black\u27 by critics, these artists sought to reexamine black aesthetics through the dialects of disenfranchisement, desire and hegemonic forms of representation in American culture. From this perspective, I will investigate the installation art of Kara Walker and Fred Wilson, illustrating how these practices inform and challenge racial stereotypes prevalent in visual culture. Walker rewrites romantic narratives of the Old South into allegorical and subversive slavery\u27 past perform horrific acts of perversion, mutilation and sexual abuse. Drawing upon Freud\u27s views on ego and body relation as well as Fanon\u27s concepts on racial objectification. I will provide new insights on the psychological dimensions of Walker\u27s work. Wilson, on the other hand, transforms reclaimed objects to encourage dialogue regarding the absence of negritude within the context of cultural institutions. In the discussion of Wilson\u27s critical method of collecting and re-presenting these artifacts, I will examine his visual narratives in comparison to Benjamin concept of historical materialism to demonstrate how the re-configuration of artifacts expose viewers to hegemonic representations that exist within museum culture

    Understanding The Typical Vacations Of U.S. Southern Travelers

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    This paper investigates important factors associated with vacation decisions made for typical vacations by U.S. southern travelers, an area given minimal focus in the marketing tourism literature. The paper effectively identifies key vacation influences to leisure travel which include distance, group size, vacation length, lead time, education level, income level, and age.  Additionally, the paper identifies nine unique types of southern vacation travelers using a cluster analysis approach. Ultimately, the paper offers a richer understanding of the pertinent factors influencing vacation decisions—particularly for individuals in the U.S. Southern region

    Alien Registration- Hill, William (Appleton, Knox County)

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    https://digitalmaine.com/alien_docs/15086/thumbnail.jp

    On the Spectra of Real and Complex Lam\'e Operators

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    We study Lam\'e operators of the form L=d2dx2+m(m+1)ω2(ωx+z0),L = -\frac{d^2}{dx^2} + m(m+1)\omega^2\wp(\omega x+z_0), with mNm\in\mathbb{N} and ω\omega a half-period of (z)\wp(z). For rectangular period lattices, we can choose ω\omega and z0z_0 such that the potential is real, periodic and regular. It is known after Ince that the spectrum of the corresponding Lam\'e operator has a band structure with not more than mm gaps. In the first part of the paper, we prove that the opened gaps are precisely the first mm ones. In the second part, we study the Lam\'e spectrum for a generic period lattice when the potential is complex-valued. We concentrate on the m=1m=1 case, when the spectrum consists of two regular analytic arcs, one of which extends to infinity, and briefly discuss the m=2m=2 case, paying particular attention to the rhombic lattices

    Reframing the Fields

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    The conception of metaphoric process elaborated by Mary Gerhart and Allan Russell illuminates a key mechanism often involved in the most significant advances in science and religion. Attention to this conceptual device provides a productive way to reframe the relationships and dialogues between the fields. The theory has compelling implications for reframing the understanding of theology and its task
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