41,999 research outputs found
System Description for a Scalable, Fault-Tolerant, Distributed Garbage Collector
We describe an efficient and fault-tolerant algorithm for distributed cyclic
garbage collection. The algorithm imposes few requirements on the local
machines and allows for flexibility in the choice of local collector and
distributed acyclic garbage collector to use with it. We have emphasized
reducing the number and size of network messages without sacrificing the
promptness of collection throughout the algorithm. Our proposed collector is a
variant of back tracing to avoid extensive synchronization between machines. We
have added an explicit forward tracing stage to the standard back tracing stage
and designed a tuned heuristic to reduce the total amount of work done by the
collector. Of particular note is the development of fault-tolerant cooperation
between traces and a heuristic that aggressively reduces the set of suspect
objects.Comment: 47 pages, LaTe
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Use of colour for hand-filled form analysis and recognition
Colour information in form analysis is currently under utilised. As technology has advanced and computing costs have reduced, the processing of forms in colour has now become practicable. This paper describes a novel colour-based approach to the extraction of filled data from colour form images. Images are first quantised to reduce the colour complexity and data is extracted by examining the colour characteristics of the images. The improved performance of the proposed method has been verified by comparing the processing time, recognition rate, extraction precision and recall rate to that of an equivalent black and white system
Border parasites: schistosomiasis control among Uganda's fisherfolk
Copyright @ 2012 Taylor & Francis. This article has been made publically available through the Brunel Open Access Publishing Fund.It is recognized that the control of schistosomisais in Uganda requires a focus on
fisherfolk. Large numbers suffer from this water-borne parasitic disease; notably along the shores of lakes Albert and Victoria and along the River Nile. Since 2004, a policy has been adopted of providing drugs, free of charge, to all those at risk. The strategy has been reported to be successful, but closer investigation reveals serious problems. This paper draws upon long-term research undertaken at three locations in northwestern and southeastern Uganda. It highlights consequences of not engaging with the day to day realities of fisherfolk
livelihoods; attributable, in part, to the fact that so many fisherfolk live and work in places located at the country’s international borders, and to a related
tendency to treat them as "feckless" and "ungovernable". Endeavours to roll out
treatment end up being haphazard, erratic and location-specific. In some places,
concerted efforts have been made to treat fisherfolk; but there is no effective
monitoring, and it is difficult to gauge what proportion have actually swallowed
the tablets. In other places, fisherfolk are, in practice, largely ignored, or are
actively harassed in ways that make treatment almost impossible. At all sites, the current reliance upon resident "community" drug distributors or staff based at static clinics and schools was found to be flawed.The Schistosomiasis Control Initiative, Imperial College, under the auspices of the Bill and Melinda Gates Foundation
Reduction of the QCD string to a time component vector potential
We demonstrate the equivalence of the relativistic flux tube model of mesons
to a simple potential model in the regime of large radial excitation. We make
no restriction on the quark masses; either quark may have a zero or finite
mass. Our primary result shows that for fixed angular momentum and large radial
excitation, the flux tube/QCD string meson with a short-range Coulomb
interaction is described by a spinless Salpeter equation with a time component
vector potential V(r) = ar - k/r.Comment: RevTeX4, 10 pages, 3 eps figure
Unambiguous determination of gravitational waveforms from binary black hole mergers
Gravitational radiation is properly defined only at future null infinity
(\scri), but in practice it is estimated from data calculated at a finite
radius. We have used characteristic extraction to calculate gravitational
radiation at \scri for the inspiral and merger of two equal mass non-spinning
black holes. Thus we have determined the first unambiguous merger waveforms for
this problem. The implementation is general purpose, and can be applied to
calculate the gravitational radiation, at \scri, given data at a finite
radius calculated in another computation.Comment: 4 pages, 3 figures, published versio
Wear and friction of impregnated mechanical carbons at temperatures to 1400 deg F /760 deg C/ in air or nitrogen
Wear and friction of impregnated mechanical carbons at high temperatures in air or nitroge
Gas ingestion and sealing capacity of helical groove fluid film seal /viscoseal/ using sodium and water as sealed fluids
Helical groove viscosity seal using sodium and water as sealed fluid
Fluoride solid lubricants for extreme temperatures and corrosive environments
Fluoride solid lubricants for extreme temperature and corrosive environment
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