628 research outputs found

    Integrated Inertial/gps

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    The presence of failures in navigation sensors can cause the determination of an erroneous aircraft state estimate, which includes position, attitude, and their derivatives. Aircraft flight control systems rely on sensor inputs to determine the aircraft state. In the case of integrated Inertial/NAVSTAR Global Positioning System (GPS), sensor failures could occur in the on-board inertial sensors or in the GPS measurements. The synergistic use of both GPS and the Inertial Navigation System (INS) allows for highly reliable fault detection and isolation of sensor failures. Integrated Inertial/GPS is a promising technology for the High Speed Civil Transport (HSCT) and the return and landing of a manned space vehicle

    Fault detection and isolation for multisensor navigation systems

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    Increasing attention is being given to the problem of erroneous measurement data for multisensor navigation systems. A recursive estimator can be used in conjunction with a 'snapshot' batch estimator to provide fault detection and isolation (FDI) for these systems. A recursive estimator uses past system states to form a new state estimate and compares it to the calculated state based on a new set of measurements. A 'snapshot' batch estimator uses a set of measurements collected simultaneously and compares solutions based on subsets of measurements. The 'snapshot' approach requires redundant measurements in order to detect and isolate faults. FDI is also referred to as Receiver Autonomous Integrity Monitoring (RAIM)

    Martin Luther King Jr. and Leadership: Building the Beloved Communities within the Academy

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    Leaders seek to build communities to further the work of universities, but vibrant communities embracing our differences and, at times, animosities remain elusive. However, King’s (Smith & Zepp, 1974) concept of the Beloved Community provides an image about how this might be possible. While abstract, King’s idea offers compelling linkages to servant leadership (Greenleaf, 1977) and how to counter the destructive, rivalistic behaviors (Kirwan, 2005) prevalent in higher education. King (1991) outlines three principles: 1) the sacredness of humans, 2) the need for freedom, and 3) the recognition of interdependence. Each principle is described and applied to the higher education context and then explored through the lenses of mimetic theory (Girard, 1989) and servant leadership

    Martin Luther King Jr. and Leadership: Building the Beloved Communities within the Academy

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    Leaders seek to build communities to further the work of universities, but vibrant communities embracing our differences and, at times, animosities remain elusive. However, King’s (Smith & Zepp, 1974) concept of the Beloved Community provides an image about how this might be possible. While abstract, King’s idea offers compelling linkages to servant leadership (Greenleaf, 1977) and how to counter the destructive, rivalistic behaviors (Kirwan, 2005) prevalent in higher education. King (1991) outlines three principles: 1) the sacredness of humans, 2) the need for freedom, and 3) the recognition of interdependence. Each principle is described and applied to the higher education context and then explored through the lenses of mimetic theory (Girard, 1989) and servant leadership

    A preliminary survey of the Bryophytes of the Sapa Bog

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    The Sapa Bog in Ozaukee County covers 5 hectares and is the southernmost black spruce bog in Wisconsin. Sedge meadow and swamp hardwoods surround an acidic center dominated by sphagnum mosses, black spruce and tamarack. Parker (1989) surveyed the fungi and Kline (1991) surveyed the vascular plants and described the water chemistry of the area. We report a total of 56 bryophyte taxa collected in the Sapa Bog from 1989 to 1990. An asterisk indicates an apparently new report for Ozaukee County (Bowers and Freckmann, 1979). Citation of moss names follows Anderson, et. al. (1990) and Crum (1984) for Sphagnum. The liverworts nomenclature follows Conard and Redfearn (1979). Voucher specimens were deposited at the UW-Stevens Point and UWM Field Station herbaria

    The role of intermolecular coupling in the photophysics of disordered organic semiconductors: Aggregate emission in regioregular polythiophene

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    We address the role of excitonic coulping on the nature of photoexcitations in the conjugated polymer regioregular poly(3-hexylthiophene). By means of temperature-dependent absorption and photoluminescence spectroscopy, we show that optical emission is overwhelmingly dominated by weakly coupled H-aggregates. The relative absorbance of the 0-0 and 0-1 vibronic peaks provides a powerfully simple means to extract the magnitude of the intermolecular coupling energy, approximately 5 and 30 meV for films spun from isodurene and chloroform solutions respectively.Comment: 10 pages, 4 figures, published in Phys. Rev. Let

    The Ursinus Weekly, March 10, 1941

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    Dr. Luther Harr warns the Haines Society of laziness in government • Dr. Catharine Macfarlane to speak at women\u27s vocational conference • Shaw called showman of the western world • Fireside chats back Food for Europe plan • Arnold releases name of prom bandleader • Soph hop to feature St. Patrick\u27s theme • \u27Beliefs that matter\u27 are discussed at Buck Hills • \u27Tri-annual\u27 includes article on employment • Men\u27s and women\u27s debating societies send three teams on road to meet nine colleges • Coach Jing Johnson to speak at baseball clinic Thursday • Ursus may be \u27bear\u27, but he\u27s on our rings • Marine officer to define place of grads in draft • Survey suggests students seek school success through thought, thrift, theology, theatricals • After fifty years: the dean reminisces • Drexel loss marks bear court finale • Wrestlers end fifth in Middle Atlantics • Snell\u27s team gets season\u27s first jolt • Girl jayvees down Temple, defeated by Rhode Island • Barab and Kuhn score freshmen over Drexel • MacMahon\u27s 153 points take varsity scoring honors; Kuhn leads frosh with 102 total • St. Paul brotherhood hears history of Schwenkfelders • Hahnemann\u27s dean speaks to pre-meds on body\u27s wonders • Beardwood Society to hear lecture on crime detection • Eilts and Yeomans to discuss Food for Europe before IRC • Committee chairmen for May Day pageant are announced • Faculty club hears Heiges present paper on education • Newman Club discusses book on life of Pope Alexander VI • Meistersingers sing at Stowe • Sturges reviews Masefield • French Club makes planshttps://digitalcommons.ursinus.edu/weekly/1811/thumbnail.jp

    Determining exciton bandwidth and film microstructure in polythiophene films using linear absorption spectroscopy

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    We analyze the linear absorption spectrum of regioregular poly(3-hexylthiophene) films spun from a variety of solvents to probe directly the film microstructure and how it depends on processing conditions. We estimate the exciton bandwidth and the percentage of the film composed of aggregates quantitatively using a weakly interacting H-aggregate model. This provides a description of the degree and quality of crystallites within the film and is in turn correlated with thin-film field-effect transistor characteristics.Comment: Applied Physics Letters (in press); 9 pages, three figure

    Nuclear Heat Sources for Cryogenic Refrigerator Applications

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    Spacecraft cryogenic refrigerators require thermal inputs on the order of 1000 W. First, the characteristics of solar-electric and radioisotope heat source systems for supplying this thermal input are compared. Then the design of a sup238sup 238Pu heat source for this application is described, and equipment for shipping and handling the heat source is discussed. (LCL
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