1,033 research outputs found

    Best Practice Description Document

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    This work received support and funding from • The BOHAB project (Biological Oceanography of Harmful Algal Blooms off the west coast of Ireland) through the National Development Plan 2000 – 2006 with the support of the Marine Institute and the Marine RTDI (Research, Technology, Development and Innovation) Measure, Productive Sector Operational Programme, Grant-aid Agreement No. ST/02/01. • the ASIMUTH project (Applied simulations and Integrated modelling for the understanding of toxic and harmful algal blooms) through the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) for Research and Technological Development - EC FP7 Programme, Space Theme, Grant Agreement No. 261860 • the MyOcean 2 project through the EC FP7 Programme, Space Theme, Grant Agreement No. 283367 • the AtlantOS project through the European Union's Horizon 2020 research and innovation programme, Grant Agreement No. 633211 • The PRIMROSE (Predicting the impact of regional scale events on the aquaculture sector) project, co-financed by the European Regional Development Fund through the Interreg Atlantic Area Programme, EAPA_182/2016 • The CoCliME (Co-development of climate services for adaptation to changing marine ecosystems) project is part of the European Research Area for Climate Services (ERA4CS), an ERA-NET initiated by JPI Climate, and funded by EPA (IE), ANR (FR), BMBF (DE), UEFISCDI (RO), RCN (NO) and FORMAS (SE), with co-funding by the European Union (Grant Agreement No. 690462).This document describes the procedural steps in creating an information product focused on toxic and harmful phytoplankton. The product is an online Harmful Algal Bloom (HAB) bulletin for aquaculturists, who can face serious operational challenges in the days after a HAB event. Data from satellite, numerical hydrodynamic models and In-situ ocean observations are organised and presented into visual information products. These products are enhanced through local expert evaluation and their interpretation is summarised in the bulletin. This document aims to provide both process overviews (the “what” of the Best Practice in producing the bulletins) and detail procedures (the “how” of the Best Practice”) so that the bulletins may be replicated in other geographic regions.European Commissio

    Vibration characteristics of 1/8-scale dynamic models of the space-shuttle solid-rocket boosters

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    Vibration tests and analyses of six 1/8 scale models of the space shuttle solid rocket boosters are reported. Natural vibration frequencies and mode shapes were obtained for these aluminum shell models having internal solid fuel configurations corresponding to launch, midburn (maximum dynamic pressure), and near endburn (burnout) flight conditions. Test results for longitudinal, torsional, bending, and shell vibration frequencies are compared with analytical predictions derived from thin shell theory and from finite element plate and beam theory. The lowest analytical longitudinal, torsional, bending, and shell vibration frequencies were within + or - 10 percent of experimental values. The effects of damping and asymmetric end skirts on natural vibration frequency were also considered. The analytical frequencies of an idealized full scale space shuttle solid rocket boosted structure are computed with and without internal pressure and are compared with the 1/8 scale model results

    Extreme value statistics and return intervals in long-range correlated uniform deviates

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    We study extremal statistics and return intervals in stationary long-range correlated sequences for which the underlying probability density function is bounded and uniform. The extremal statistics we consider e.g., maximum relative to minimum are such that the reference point from which the maximum is measured is itself a random quantity. We analytically calculate the limiting distributions for independent and identically distributed random variables, and use these as a reference point for correlated cases. The distributions are different from that of the maximum itself i.e., a Weibull distribution, reflecting the fact that the distribution of the reference point either dominates over or convolves with the distribution of the maximum. The functional form of the limiting distributions is unaffected by correlations, although the convergence is slower. We show that our findings can be directly generalized to a wide class of stochastic processes. We also analyze return interval distributions, and compare them to recent conjectures of their functional form

    Extreme value distributions for weakly correlated fitnesses in block model

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    We study the limit distribution of the largest fitness for two models of weakly correlated and identically distributed random fitnesses. The correlated fitness is given by a linear combination of a fixed number of independent random variables drawn from a common parent distribution. We find that for certain class of parent distributions, the extreme value distribution for correlated random variables can be related either to one of the known limit laws for independent variables or the parent distribution itself. For other cases, new limiting distributions appear. The conditions under which these results hold are identified.Comment: Expanded, added reference

    Sub-gap conductance in ferromagnetic-superconducting mesoscopic structures

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    We study the sub-gap conductance of a ferromagnetic mesoscopic region attached to a ferromagnetic and a superconducting electrode by means of tunnel junctions. In the absence of the exchange field, the ratio r=γ/ϵTr= \gamma / \epsilon_T of the two tunnel junction resistances determines the behaviour of the sub-gap conductance which possesses a zero-bias peak for r≫1r\gg 1 and for r≪1r\ll 1 a peak at finite voltage. We show that the inclusion of the exchange field leads to a peak splitting for r≪1r\ll 1, while it shifts the zero-bias anomaly to finite voltages for r≫1r\gg 1.Comment: 5 pages revte

    Repositioning of special schools within a specialist, personalised educational marketplace - the need for a representative principle

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    This paper considers how notions of inclusive education as defined in the United Nations Educational, Scientific and Cultural Organization (UNESCO) Salamanca Agreement (1994) have become dissipated, and can be developed and reframed to encourage their progress. It analyses the discourse within a range of academic, legal and media texts, exploring how this dissipation has taken place within the UK. Using data from 78 specialist school websites it contextualises this change in the use of the terms and ideas of inclusion with the rise of two other constructs, the 'specialist school' and 'personalisation'. It identifies the need for a precisely defined representative principle to theorise the type of school which inclusion aims to achieve, which cannot be subsumed by segregated providers. It suggests that this principle should not focus on the individual, but draw upon a liberal/democratic view of social justice, underlining inclusive education's role in removing social barriers that prevent equity, access and participation for all

    Foundation and empire : a critique of Hardt and Negri

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    In this article, Thompson complements recent critiques of Hardt and Negri's Empire (see Finn Bowring in Capital and Class, no. 83) using the tools of labour process theory to critique the political economy of Empire, and to note its unfortunate similarities to conventional theories of the knowledge economy

    The global picture of self-similar and not self-similar decay in Burgers Turbulence

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    This paper continue earlier investigations on the decay of Burgers turbulence in one dimension from Gaussian random initial conditions of the power-law spectral type E0(k)∼∣k∣nE_0(k)\sim|k|^n. Depending on the power nn, different characteristic regions are distinguished. The main focus of this paper is to delineate the regions in wave-number kk and time tt in which self-similarity can (and cannot) be observed, taking into account small-kk and large-kk cutoffs. The evolution of the spectrum can be inferred using physical arguments describing the competition between the initial spectrum and the new frequencies generated by the dynamics. For large wavenumbers, we always have k−2k^{-2} region, associated to the shocks. When nn is less than one, the large-scale part of the spectrum is preserved in time and the global evolution is self-similar, so that scaling arguments perfectly predict the behavior in time of the energy and of the integral scale. If nn is larger than two, the spectrum tends for long times to a universal scaling form independent of the initial conditions, with universal behavior k2k^2 at small wavenumbers. In the interval 2<n2<n the leading behaviour is self-similar, independent of nn and with universal behavior k2k^2 at small wavenumber. When 1<n<21<n<2, the spectrum has three scaling regions : first, a ∣k∣n|k|^n region at very small kk\ms1 with a time-independent constant, second, a k2k^2 region at intermediate wavenumbers, finally, the usual k−2k^{-2} region. In the remaining interval, n<−3n<-3 the small-kk cutoff dominates, and nn also plays no role. We find also (numerically) the subleading term ∼k2\sim k^2 in the evolution of the spectrum in the interval −3<n<1-3<n<1. High-resolution numerical simulations have been performed confirming both scaling predictions and analytical asymptotic theory.Comment: 14 pages, 19 figure

    Last passage percolation and traveling fronts

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    We consider a system of N particles with a stochastic dynamics introduced by Brunet and Derrida. The particles can be interpreted as last passage times in directed percolation on {1,...,N} of mean-field type. The particles remain grouped and move like a traveling wave, subject to discretization and driven by a random noise. As N increases, we obtain estimates for the speed of the front and its profile, for different laws of the driving noise. The Gumbel distribution plays a central role for the particle jumps, and we show that the scaling limit is a L\'evy process in this case. The case of bounded jumps yields a completely different behavior
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