30,788 research outputs found

    Quartz Crystal Microbalance (QCM) monitor of contamination for LES-8/9

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    A Quartz Crystal Microbalance (QCM) was used to monitor condensable contamination during the launching of two Lincoln Laboratory Experimental Satellites--LES-8 and LES-9. The QCM was installed on the dispenser truss and measured contamination by means of a frequency shift of a quartz crystal oscillator. By using a special crystal cut and a second reference quartz crystal, the sensor had extreme sensitivity and remarkable temperature independence. A 1-Hz frequency shift, which corresponds to 3.5 x 10 to the -9th power g/sq cm was resolved by the flight instrumentation

    Ground data handling for LANDSAT-D

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    The present plans for the LANDSAT D ground data handling are described in relationship to the mission objectives and the planned spacecraft system. The end to end data system is presented with particular emphasis on the data handling plans for the new instrument, the Thematic Mapper. This instrument generates ten times the amount of data per scene as the present Multispectral Scanner, and this resulting data rate and volume are discussed as well as possible new data techniques to handle them such as image compression

    Space data handling at goddard space flight center

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    Data processing system including acquisition, handling, and final analysis for magnetic tapes for computer program of tracking station data at Goddard Space Flight Cente

    Three-axis adjustable loading structure

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    A three axis adjustable loading structure for testing the movable surfaces of aircraft by applying pressure, is described. The device has three electric drives where the wall angle, horizontal position, and vertical position of the test device can be rapidly and accurately positioned

    Who pays for renewables? Increasing renewable subsidisation due to increased datacentre demand in Ireland. ESRI WP566, June 2017

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    Demand from datacentres makes up a rapidly growing portion of electricity demand in Ireland. Increased demand in turn gives rise to increased renewable generation, mandated by government targets, and a corresponding increase in subsidisation levels. The current method of apportioning renewable subsidy costs may lead to consumers other than datacentres bearing this excess cost of subsidisation. This letter calculates the expected impact on these consumers

    WHO PAYS FOR RENEWABLES? THE EFFECT OF DATACENTRES ON RENEWABLE SUBSIDIES. ESRI Research Bulletin 2019/11

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    Ireland faces several targets for renewable energy usage, across the heating, transport and electricity sectors. These targets are set as a proportion of total energy usage. In the case of electricity, 40% of electricity must be generated from renewable sources by 2020. To meet this target, renewable electricity generation is subsidised through the Public Service Obligation levy, which appears on all consumersā€™ bills. The PSO is levied on residential consumers, commercial consumers and large industrial consumers according to their contribution to peak demand ā€“ the more the sector contributes to peak demand, the higher the portion of PSO that they pay

    Inference of historical population-size changes with allele-frequency data

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    With up to millions of nearly neutral polymorphisms now being routinely sampled in population-genomic surveys, it is possible to estimate the site-frequency spectrum of such sites with high precision. Each frequency class reflects a mixture of potentially unique demographic histories, which can be revealed using theory for the probability distributions of the starting and ending points of branch segments over all possible coalescence trees. Such distributions are completely independent of past population history, which only influences the segment lengths, providing the basis for estimating average population sizes separating tree-wide coalescence events. The history of population-size change experienced by a sample of polymorphisms can then be dissected in a model-flexible fashion, and extension of this theory allows estimation of the mean and full distribution of long-term effective population sizes and ages of alleles of specific frequencies. Here, we outline the basic theory underlying the conceptual approach, develop and test an efficient statistical procedure for parameter estimation, and apply this to multiple population-genomic datasets for the microcrustacean Daphnia pulex

    The size of the largest fluctuations in a market model with Markovian switching

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    This paper considers the size of the large fluctuations of a stochastic differential equation with Markovian switching. We concentrate on processes which obey the Law of the Iterated Logarithm, or obey upper and lower iterated logarithm growth bounds on their almost sure partial maxima. The results are applied to financial market models which are subject to random regime shifts. We prove that the security exhibits the same long-run growth properties and deviations from the trend rate of growth as conventional geometric Brownian motion, and also that the returns, which are non-Gaussian, still exhibit the same growth rate in their almost sure large deviations as stationary continuous-time Gaussian processes
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