7,185 research outputs found

    Through a glass darkly: a case for the study of virtual space

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    This paper begins to examine the similarities and differences between virtual space and real space, as taken from anarchitectural (as opposed to a biological, psychological, geographic, philosophical or information theoretic)standpoint. It continues by introducing a number of criteria, suggested by the authors as being necessary for virtualspace to be used in a manner consistent with our experience of real space. Finally, it concludes by suggesting apedagogical framework for the benefits and associated learning outcomes of the study and examination of thisrelationship. This is accompanied by examples of recent student work, which set out to investigate this relationship

    Design of an integrated shallow water wave experiment

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    The experimental design and instrumentation for an integrated shallow-water surface gravity wave experiment is discussed. The experiment required the measurement of the water surface elevation, meteorological parameters, and directional spectra at a number of locations on a shallow lake. In addition, to acquire data under a wide range of conditions, an experimental period of three years was required. A system of telephone and radio modem links were installed to enable real-time monitoring of instrument performance at eight separate measurement locations on the lake. This system also enabled logging sessions to be optimized to ensure the maximum possible data return from this extended experimentIEEE Oceanic Engineering Societ

    The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS) prisons project pilot study: protocol for a randomised controlled trial comparing dihydrocodeine and buprenorphine for opiate detoxification

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    Background In the United Kingdom (UK), there is an extensive market for the class 'A' drug heroin. Many heroin users spend time in prison. People addicted to heroin often require prescribed medication when attempting to cease their drug use. The most commonly used detoxification agents in UK prisons are buprenorphine, dihydrocodeine and methadone. However, national guidelines do not state a detoxification drug of choice. Indeed, there is a paucity of research evaluating the most effective treatment for opiate detoxification in prisons. This study seeks to address the paucity by evaluating routinely used interventions amongst drug using prisoners within UK prisons. Methods/Design The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS) Prisons Pilot Study will use randomised controlled trial methodology to compare the open use of buprenorphine and dihydrocodeine for opiate detoxification, given in the context of routine care, within HMP Leeds. Prisoners who are eligible and give informed consent will be entered into the trial. The primary outcome measure will be abstinence status at five days post detoxification, as determined by a urine test. Secondary outcomes during the detoxification and then at one, three and six months post detoxification will be recorded

    Synchronized pulse control of decoherence

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    We present a new strategy for multipulse control over decoherence. When a two-level system interacts with a reservoir characterized by a specific frequency, we find that the decoherence is effectively suppressed by synchronizing the pulse-train application with the dynamical motion of the reservoir.Comment: 14 pages, 8 figure

    Environmental Dependence of the Fundamental Plane of Galaxy Clusters

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    Galaxy clusters approximate a planar (FP) distribution in a three-dimensional parameter space which can be characterized by optical luminosity, half-light radius, and X-ray luminosity. Using a high-quality catalog of cluster redshifts, we find the nearest neighbor cluster for those common to an FP study and the cluster catalog. Examining scatter about the FP, we find 99.2% confidence that it is dependent on nearest neighbor distance. Our study of X-Ray clusters finds that those with high central gas densities are systematically closer to neighbor clusters. If we combine results here with those of Fritsch and Buchert, we find an explanation for some of our previous conclusions: Clusters in close proximity to other clusters are more likely to have massive cooling flows because they are more relaxed and have higher central gas densities.Comment: Accepted for publication in Astrophysical Journal Letters. Moderate revisions, including more statistical analysis and discussion. Latex, 7 page

    Decoherence Rates in Large Scale Quantum Computers and Macroscopic Systems

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    Markovian regime decoherence effects in quantum computers are studied in terms of the fidelity for the situation where the number of qubits N becomes large. A general expression giving the decoherence time scale in terms of Markovian relaxation elements and expectation values of products of system fluctuation operators is obtained, which could also be applied to study decoherence in other macroscopic systems such as Bose condensates and superconductors. A standard circuit model quantum computer involving three-state lambda system ionic qubits is considered, with qubits localised around well-separated positions via trapping potentials. The centre of mass vibrations of the qubits act as a reservoir. Coherent one and two qubit gating processes are controlled by time dependent localised classical electromagnetic fields that address specific qubits, the two qubit gating processes being facilitated by a cavity mode ancilla, which permits state interchange between qubits. With a suitable choice of parameters, it is found that the decoherence time can be made essentially independent of N.Comment: Minor revisions. To be published in J Mod Opt. One figur
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