Lancaster E-Prints

    Using a Grid-Enabled Wireless Sensor Network for Flood Management

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    Flooding is becoming an increasing problem. As a result there is a need to deploy more sophisticated sensor networks to detect and react to flooding. This paper outlines a demonstration that illustrates our proposed solution to this problem involving embedded wireless hardware, component based middleware and overlay networks

    A Middleware Approach for Pervasive Grid Environments

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    Next-generation Grid applications will operate within and across many heterogeneous network types; will employ a wide range of device types ranging from supercomputers to sensor motes; and will require many more “interaction paradigms” than merely RPC and messagepassing (e.g., publish-subscribe, multicast, tuple spaces etc.). In this paper, we propose a middleware approach to meeting these emerging needs. Our approach is to provide a highly flexible “overlay network framework” that underpins an extensible set of plug-in interaction paradigms. The middleware is structured using a lightweight run-time component model that enables appropriate profiles to be configured on a wide rage of device types, and facilitates runtime reconfiguration (as required for reasons of adaptation to dynamic environments). For proof of concept, we are exploring a wildfire scenario which involves mobile groups of firefighters, mobile sensors, control centres, and access to parts of the wider fixed Grid for simulation. We are also investigating the application of our approach more generally in the management of the “e-Environment”

    VARD2:a tool for dealing with spelling variation in historical corpora

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    When applying corpus linguistic techniques to historical corpora, the corpus researcher should be cautious about the results obtained. Corpus annotation techniques such as part of speech tagging, trained for modern languages, are particularly vulnerable to inaccuracy due to vocabulary and grammatical shifts in language over time. Basic corpus retrieval techniques such as frequency profiling and concordancing will also be affected, in addition to the more sophisticated techniques such as keywords, n-grams, clusters and lexical bundles which rely on word frequencies for their calculations. In this paper, we highlight these problems with particular focus on Early Modern English corpora. We also present an overview of the VARD tool, our proposed solution to this problem, which facilitates pre-processing of historical corpus data by inserting modern equivalents alongside historical spelling variants. Recent improvements to the VARD tool include the incorporation of techniques used in modern spell checking software

    Gate-induced interlayer asymmetry in ABA-stacked trilayer graphene.

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    We calculate the electronic band structure of ABA-stacked trilayer graphene in the presence of external gates, using a self-consistent Hartree approximation to take account of screening. In the absence of a gate potential, there are separate pairs of linear and parabolic bands at low energy. A gate field perpendicular to the layers breaks mirror reflection symmetry with respect to the central layer and hybridizes the linear and parabolic low-energy bands, leaving a chiral Hamiltonian essentially different from that of monolayer or bilayer graphene. Using the self-consistent Born approximation, we find that the density of states and the minimal conductivity in the presence of disorder generally increase as the gate field increases, in sharp contrast with bilayer graphene

    Effects of the dominant in Secret Window.

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    This paper seeks to identify and examine 'problematic' aesthetic strategies in David Koepp's Secret Window (2004). Arguing that the film fits into a specific 'puzzle film' category favouring self-deceiving protagonists and surprise twists, the paper seeks to account for the negative critical reaction accrued by the film's denouement. Most centrally, I invoke the Russian Formalist's concept of the 'dominant' in order to suggest how Secret Window subordinates textual elements to the film's narrative revelation. It is this prioritising of the main plot twist that accounts for many of the film's dramaturgically contentious tactics. The paper demonstrates the means by which Secret Window cuts against the grain of Hollywood storytelling norms; it suggests that the film manipulates character engagement in a way that exceeds the puzzle film's traditional reshuffling of sympathies; and it indicates how the film deploys generic convention and allusion to engender a highly self-conscious and repressive narration. These arguments aim to show that the film displays bold and sophisticated aesthetic strategies. More broadly, the paper argues that by analysing problematic examples of a film genre, we can usefully disclose the aesthetic principles that underpin the genre's more successful films

    NETKIT: A software component-based approach to programmable networking

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    While there has already been significant research in support of openness and programmability in networks, this paper argues that there remains a need for generic support for the integrated development, deployment and management of programmable networking software. We further argue that this support should explicitly address the management of run-time reconfiguration of systems, and should be independent of any particular programming paradigm (e.g. active networking or open signaling), programming language, or hardware/operating system platform. In line with these aims, we outline an approach to the structuring of programmable networking software in terms of a ubiquitously applied software component model that can accommodate all levels of a programmable networking system from low-level system support, to in-band packet handling, to active networking execution environments to signaling and coordination

    Does GABA act as a signal in plants? : hints from molecular studies.

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    GABA is a non-protein amino acid that accumulates rapidly in plant tissues in response to biotic and abiotic stress. There have been a number of suggestions as to the role that GABA might play in plants, ranging from a straightforward involvement in N metabolism to a signal mediating plant-animal and plant-microbe interactions. It has also been several proposed that it might function as an intracellular signalling molecule in plants. Here, we discuss recent evidence that plant cells respond at the molecular level to the presence of applied GABA. We argue that these data might serve as the basis for investigating the possible signalling role for GABA in plant development and stress responses in more detail

    Radiative forcing in the 21st century due to ozone changes in the troposphere and the lower stratosphere

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    Radiative forcing due to changes in ozone is expected for the 21st century. An assessment on changes in the tropospheric oxidative state through a model intercomparison ("OxComp'') was conducted for the IPCC Third Assessment Report (IPCC-TAR). OxComp estimated tropospheric changes in ozone and other oxidants during the 21st century based on the "SRES'' A2p emission scenario. In this study we analyze the results of 11 chemical transport models (CTMs) that participated in OxComp and use them as input for detailed radiative forcing calculations. We also address future ozone recovery in the lower stratosphere and its impact on radiative forcing by applying two models that calculate both tropospheric and stratospheric changes. The results of OxComp suggest an increase in global-mean tropospheric ozone between 11.4 and 20.5 DU for the 21st century, representing the model uncertainty range for the A2p scenario. As the A2p scenario constitutes the worst case proposed in IPCC-TAR we consider these results as an upper estimate. The radiative transfer model yields a positive radiative forcing ranging from 0.40 to 0.78 W m(-2) on a global and annual average. The lower stratosphere contributes an additional 7.5-9.3 DU to the calculated increase in the ozone column, increasing radiative forcing by 0.15-0.17 W m(-2). The modeled radiative forcing depends on the height distribution and geographical pattern of predicted ozone changes and shows a distinct seasonal variation. Despite the large variations between the 11 participating models, the calculated range for normalized radiative forcing is within 25%, indicating the ability to scale radiative forcing to global-mean ozone column change

    Processes influencing ozone levels in Alaskan forest fire plumes during long-range transport over the North Atlantic

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    [1] A case of long-range transport of a biomass burning plume from Alaska to Europe is analyzed using a Lagrangian approach. This plume was sampled several times in the free troposphere over North America, the North Atlantic and Europe by three different aircraft during the IGAC Lagrangian 2K4 experiment which was part of the ICARTT/ ITOP measurement intensive in summer 2004. Measurements in the plume showed enhanced values of CO, VOCs and NOy, mainly in form of PAN. Observed O-3 levels increased by 17 ppbv over 5 days. A photochemical trajectory model, CiTTyCAT, was used to examine processes responsible for the chemical evolution of the plume. The model was initialized with upwind data and compared with downwind measurements. The influence of high aerosol loading on photolysis rates in the plume was investigated using in situ aerosol measurements in the plume and lidar retrievals of optical depth as input into a photolysis code (Fast-J), run in the model. Significant impacts on photochemistry are found with a decrease of 18% in O-3 production and 24% in O-3 destruction over 5 days when including aerosols. The plume is found to be chemically active with large O-3 increases attributed primarily to PAN decomposition during descent of the plume toward Europe. The predicted O-3 changes are very dependent on temperature changes during transport and also on water vapor levels in the lower troposphere which can lead to O-3 destruction. Simulation of mixing/dilution was necessary to reproduce observed pollutant levels in the plume. Mixing was simulated using background concentrations from measurements in air masses in close proximity to the plume, and mixing timescales ( averaging 6.25 days) were derived from CO changes. Observed and simulated O-3/CO correlations in the plume were also compared in order to evaluate the photochemistry in the model. Observed slopes change from negative to positive over 5 days. This change, which can be attributed largely to photochemistry, is well reproduced by multiple model runs even if slope values are slightly underestimated suggesting a small underestimation in modeled photochemical O-3 production. The possible impact of this biomass burning plume on O-3 levels in the European boundary layer was also examined by running the model for a further 5 days and comparing with data collected at surface sites, such as Jungfraujoch, which showed small O-3 increases and elevated CO levels. The model predicts significant changes in O-3 over the entire 10 day period due to photochemistry but the signal is largely lost because of the effects of dilution. However, measurements in several other BB plumes over Europe show that O-3 impact of Alaskan fires can be potentially significant over Europe
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