997 research outputs found

    The Tangible Contribution of R&D Spending Foreign-Owned Plants to a Host Region: a Plant Level Study of the Irish Manufacturing Sector (1980-1996)

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    Using plant level data from the Irish manufacturing sector, we explore the relationship between foreign direct investment (FDI) and economic growth in Ireland. The central question explored in this paper is whether the tangible contribution of MNC plants which undertake R&D investment in Ireland is greater than the tangible contribution of MNC plants which undertake no R&D investment. We conclude that the scale of R&D activity in a plant is an important determinant in (i) lengthening the duration over which that plant will remain in Ireland and (ii) in improving the quality of employment created in that plant.

    Antimicrobial Susceptibilities of Aerobic Isolates from Respiratory Samples of Young New Zealand Horses

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    3rd Annual IEEE Energy Conversion Congress and Exposition, ECCE 2011, Phoenix, AZ, 17-22 September 2011This paper presents a method of mitigating the transient overshoots of DC-DC converters operating with large load disturbances. The method involves a small auxiliary power circuit with a complementary control scheme that provides a smooth absorption and release of excess energy from and to the main DC-DC converter in the events of large load changes. This control mechanism interactively mitigates the large transient overshoots which would otherwise appear at the converter output. Since the control scheme involves an adjustable-energy-storage feature, the proposed solution is effective for any level of step-load change within a pre-specified range.Department of Electronic and Information EngineeringRefereed conference pape

    Numerically optimized coronagraph designs for the Habitable Exoplanet Imaging Mission (HabEx) concept

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    The primary science goal of the Habitable Exoplanet Imaging Mission (HabEx), one of four candidate flagship missions under investigation, is to image and spectrally characterize Earth-like exoplanets. It is well known that pupil obscurations degrade coronagraphic performance and complicate coronagraph design, so HabEx is planned to have an off-axis, unobscured primary mirror. We utilize the circular symmetry of the aperture to investigate 1D-radial coronagraph optimization methods that are prohibitively time-consuming or intractable in 2D, such as diffractive pupil remapping and concurrent, multi-plane optimization. We also directly constrain sensitivities to dynamic, low-order Zernike aberrations, which are separable in polar coordinates and can thus be propagated as 1D-radial integrals. The mask technologies in our designs claim heritage from the extensive modeling and testbed experiments performed by the Wide-Field Infrared Survey Telescope (WFIRST) Coronagraph Instrument (CGI) project. In this paper, we detail our optimization methods and outline future work to complete our design survey

    Nodal areas in coherent beams

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    Whereas nodal points having zero amplitude are well-known wave phenomena, destructive interference across a continuous area is rare. In fact, these strange states seem to defy nature’s “abhorrence of nothingness.” Philosophizing aside, we report general schemes for constructing a nodal area in a spatially coherent beam of light by use of a lossless phase mask. Theoretical, numerical, and experimental results are presented. Nodal areas are important for high contrast imaging, laser surfacing, radiation shielding, and other structured light applications. Moreover, these results transcend optics and open the possibility of achieving nodal area wave functions in quantum, acoustic, and other coherent wave systems
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