100,678 research outputs found

    'It was absolute hell': inside the private prison

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    As part of a broader current of critique of the economic and political dynamics of prison privatisation - a critique that initially emanated from the USA - this paper focuses on Scotland and on research carried out at its then only private penal institution, HMP Kilmarnock. The authors dismantle the government's case for extending prison privatisation by drilling deep into the experience of Kilmarnock and demonstrating the deleterious effects of marketisation for prison officers and prisoners alike. Degraded pay and conditions and systemic understaffing corroded morale, exposed staff and inmates to risk, and contributed to massive officer turnover. Compelling evidence comes from sources ordinarily unavailable to critical researchers,such as internal company and government documentation

    Assimilation of MSG land-surface temperature into land-surface model simulations to constrain estimates of surface energy budget in West Africa

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    In the semi-arid regions of West Africa the surface energy partition is related closely to near surface moisture availability. Such moisture availability exhibits marked heterogeneity at scales of a few kilometres, related to the passage of storm systems during the previous one or two days. The associated variations in surface fluxes affect planetary boundary layer properties at the mesoscale, which may in turn affect rainfall and the seasonal development of the West African monsoon. Atmosphere models used to study this land-atmosphere coupling are sensitive to the soil moisture initial condition. There exists no observation network for soil moisture in West Africa, so models rely on data from atmosphere analyses, which are often unable to describe adequately surface variation at the mesoscale. Additionally, retrospective estimates of the seasonal surface energy and water budgets using land-surface models are biased by persistent model errors in soil moisture. Anomalies in near-surface (top few centimetres) soil moisture are anti-correlated with anomalies in land-surface brightness temperature, which is observed by the SEVIRI thermal infra-red sensors onboard the Meteosat Second Generation (MSG) satellites. Here, we present methods developed for assimilating the MSG land-surface temperature product from the Land SAF to constrain estimates of the surface energy and water budgets using the JULES land-surface model. This MSG temperature product has a pixel size of approximately 3 km in this region, and is known to provide information of surface wetness anomalies at the scales of interest. The results will provide, for a large region of West Africa, improved initial conditions for modelling studies and seasonal estimates of the surface energy and water budgets

    Variational approximations to homoclinic snaking

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    We investigate the snaking of localised patterns, seen in numerous physical applications, using a variational approximation. This method naturally introduces the exponentially small terms responsible for the snaking structure, that are not accessible via standard multiple-scales asymptotic techniques. We obtain the symmetric snaking solutions and the asymmetric 'ladder' states, and also predict the stability of the localised states. The resulting approximate formulas for the width of the snaking region show good agreement with numerical results.Comment: 4 pages, 3 figures, submitte

    Accounting for human rights : doxic health and safety practices - the accounting lessons from ICL

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    This paper is concerned with a specific human right - the right to work in a safe environment. It sets out a case for developing a new form of account of health and safety in any organisational setting. It draws upon the theoretical insights of Pierre Bourdieu taking inspiration from his assertion that in order to understand the 'logic' of the worlds we live in we need to immerse ourselves into the particularity of an empirical reality. In this case the paper, analyses a preventable industrial disaster which occurred in Glasgow, Scotland which killed nine people and injured 33 others. From this special case of what is possible, the paper unearths the underlying structures of symbolic violence of the UK State, the Health and Safety Executive and capital with respect to health and safety at work. While dealing with one specific country (Scotland), the analysis can be used to question health and safety regimes and other forms of symbolic violence across the globe

    Proportional-integral-plus (PIP) control of time delay systems

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    The paper shows that the digital proportional-integral-plus (PIP) controller formulated within the context of non-minimum state space (NMSS) control system design methodology is directly equivalent, under certain non-restrictive pole assignment conditions, to the equivalent digital Smith predictor (SP) control system for time delay systems. This allows SP controllers to be considered within the context of NMSS state variable feedback control, so that optimal design methods can be exploited to enhance the performance of the SP controller. Alternatively, since the PIP design strategy provides a more flexible approach, which subsumes the SP controller as one option, it provides a superior basis for general control system design. The paper also discusses the robustness and disturbance response characteristics of the two PIP control structures that emerge from the analysis and demonstrates the efficacy of the design methods through simulation examples and the design of a climate control system for a large horticultural glasshouse system

    Distributed monitoring and control of future power systems via grid computing

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    It is now widely accepted within the electrical power supply industry that future power systems operates with significantly larger numbers of small-scale highly dispersed generation units that use renewable energy sources and also reduce carbon dioxide emissions. In order to operate such future power systems securely and efficiently it will be necessary to monitor and control output levels and scheduling when connecting such generation to a power system especially when it is typically embedded at the distribution level. Traditional monitoring and control technology that is currently employed at the transmission level is highly centralized and not scalable to include such significant increases in distributed and embedded generation. However, this paper proposes and demonstrates the adoption of a relatively new technology 'grid computing' that can provide both a scalable and universally adoptable solution to the problems associated with the distributed monitoring and control of future power systems

    A study of publish/subscribe systems for real-time grid monitoring

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    Monitoring and controlling a large number of geographically distributed scientific instruments is a challenging task. Some operations on these instruments require real-time (or quasi real-time) response which make it even more difficult. In this paper, we describe the requirements of distributed monitoring for a possible future electrical power grid based on real-time extensions to grid computing. We examine several standards and publish/subscribe middleware candidates, some of which were specially designed and developed for grid monitoring. We analyze their architecture and functionality, and discuss the advantages and disadvantages. We report on a series of tests to measure their real-time performance and scalability

    Proportional-integral-plus (PIP) control of the ALSTOM gasifier problem

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    Although it is able to exploit the full power of optimal state variable feedback within a non-minimum state-space (NMSS) setting, the proportional-integral-plus (PIP) controller is simple to implement and provides a logical extension of conventional proportional-integral and proportional-integral-derivative (PI/PID) controllers, with additional dynamic feedback and input compensators introduced automatically by the NMSS formulation of the problem when the process is of greater than first order or has appreciable pure time delays. The present paper applies the PIP methodology to the ALSTOM benchmark challenge, which takes the form of a highly coupled multi-variable linear model, representing the gasifier system of an integrated gasification combined cycle (IGCC) power plant. In particular, a straightforwardly tuned discrete-time PIP control system based on a reduced-order backward-shift model of the gasifier is found to yield good control of the benchmark, meeting most of the specified performance requirements at three different operating points

    Benchmark full configuration-interaction calculations on H2O, F- and F

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    Full configuration-interaction calculations are reported, and compared to other methods, for H2O at its equilibrium geometry and at two geometries with the H-O bonds stretched. Since the percentage of the self-consistent field (SCF) reference in the full configuration-interaction (FCI) wave function decreases greatly with the bond elongation, the accuracy of techniques based on a single reference do not compare well with the FCI results. However, the results from a complete active space SCF/multireference configuration-interaction (CASSCF/MRCI) treatment are in good agreement with the FCI. Correlation effects in F compared to Ne are far more similar than for F- compared to Ne, despite F- and Ne being isoelectronic. Since the importance of higher than double excitations is more important for F- than F, a very high percentage of the correlation must be obtained to accurately compute the electron affinity. In a CASSCF/MRCI treatment the higher than quadruple excitations contribute 0.02 eV to the electron affinity (EA), even for modest basis sets
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