31,001 research outputs found

    A Tuner that Accelerates Parameters

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    We propose a tuner, suitable for adaptive control and (in its discrete-time version) adaptive filtering applications, that sets the second derivative of the parameter estimates rather than the first derivative as is done in the overwhelming majority of the literature. Comparative stability and performance analyses are presented.Comment: 6 pages, 4 figure

    Giving urban policy its 'medical': assessing the place of health in area-based regeneration

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    How does regeneration affect health and how have successive urban policy evaluations sought to measure such impacts? This article draws on a systematic review of national-level evaluation documentation relating to government-funded, area-based regeneration initiatives in the UK since 1980. The review examined whether health impacts had been intended and, if so, how they had been measured. The process and difficulties of conducting the review raise significant questions about policy formulation and evaluation. Is evidence-based policy possible where evaluations are not stored centrally? In short, a model policy development as 'enlightened' or incremental is hard to sustain where a lack of systematic storage of data means that researchers, policy makers and practitioners may struggle to produce clear answers to important policy questions

    Crop protection in organic agriculture - a simple matter?

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    This report was presented at the UK Organic Research 2002 Conference. Crop protection strategies in organic agriculture and horticulture aim to prevent pest, disease and weed problems through optimisation of the cropping system as a whole. Choice of crops and varieties within the rotation and use of appropriate husbandry practices are critical to the success of the system and direct curative action against pests and diseases is rarely necessary. Research is urgently needed to determine strategies for control of key pests and diseases in organic systems if UK organic agriculture is to expand to meet increasing consumer demand. This paper describes current prevention and control strategies for pests, diseases and weeds in UK organic agriculture and identifies problems that are currently limiting expansion of the industry

    Do urban regeneration programmes improve public health and reduce health inequalities? A synthesis of the evidence from UK policy and practice (1980–2004)

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    Objectives: To synthesise data on the impact on health and key socioeconomic determinants of health and health inequalities reported in evaluations of national UK regeneration programmes. Data Sources: Eight electronic databases were searched from 1980 to 2004 (IBSS, COPAC, HMIC, IDOX, INSIDE, Medline, Urbadisc/Accompline, Web of Knowledge). Bibliographies of located documents and relevant web sites were searched. Experts and government departmental libraries were also contacted. Review methods: Evaluations that reported achievements drawing on data from at least two target areas of a national urban regeneration programme in the UK were included. Process evaluations and evaluations reporting only business outcomes were excluded. All methods of evaluation were included. Impact data on direct health outcomes and direct measures of socioeconomic determinants of health were narratively synthesised. Results: 19 evaluations reported impacts on health or socioeconomic determinants of health; data from 10 evaluations were synthesised. Three evaluations reported health impacts; in one evaluation three of four measures of self reported health deteriorated, typically by around 4%. Two other evaluations reported overall reductions in mortality rates. Most socioeconomic outcomes assessed showed an overall improvement after regeneration investment; however, the effect size was often similar to national trends. In addition, some evaluations reported adverse impacts. Conclusion: There is little evidence of the impact of national urban regeneration investment on socioeconomic or health outcomes. Where impacts have been assessed, these are often small and positive but adverse impacts have also occurred. Impact data from future evaluations are required to inform healthy public policy; in the meantime work to exploit and synthesise "best available" data is required

    Robustness of the nodal d-wave spectrum to strongly fluctuating competing order

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    We resolve an existing controversy between, on the one hand, convincing evidence for the existence of competing order in underdoped cuprates, and, on the other hand, spectroscopic data consistent with a seemingly homogeneous d-wave superconductor in the very same compounds. Specifically, we show how short-range fluctuations of the competing order essentially restore the nodal d-wave spectrum from the qualitatively distinct folded dispersion resulting from homogeneous coexisting phases. The signatures of the fluctuating competing order can be found mainly in a splitting of the antinodal quasi-particles and, depending of the strength of the competing order, also in small induced nodal gaps as found in recent experiments on underdoped La{2-x}SrxCuO4.Comment: 5 pages, 4 figure

    Turbine blade and vane heat flux sensor development, phase 2

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    The development of heat flux sensors for gas turbine blades and vanes and the demonstration of heat transfer measurement methods are reported. The performance of the heat flux sensors was evaluated in a cylinder in cross flow experiment and compared with two other heat flux measurement methods, the slug calorimeter and a dynamic method based on fluctuating gas and surface temperature. Two cylinders, each instrumented with an embedded thermocouple sensor, a Gardon gauge, and a slug calorimeter, were fabricated. Each sensor type was calibrated using a quartz lamp bank facility. The instrumented cylinders were then tested in an atmospheric pressure combustor rig at conditions up to gas stream temperatures of 1700K and velocities to Mach 0.74. The test data are compared to other measurements and analytical prediction

    Digital computer processing of LANDSAT data for North Alabama

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    Computer processing procedures and programs applied to Multispectral Scanner data from LANDSAT are described. The output product produced is a level 1 land use map in conformance with a Universal Transverse Mercator projection. The region studied was a five-county area in north Alabama

    Experimental position-time entanglement with degenerate single photons

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    We report an experiment in which two-photon interference occurs between degenerate single photons that never meet. The two photons travel in opposite directions through our fibre-optic interferometer and interference occurs when the photons reach two different, spatially separated, 2-by-2 couplers at the same time. We show that this experiment is analogous to the conventional Franson-type entanglement experiment where the photons are entangled in position and time. We measure wavefunction overlaps for the two photons as high as 94 ±\pm 3%.Comment: Updated to published version, new fig. 4., corrected typo
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