25,589 research outputs found

    Why can't every year be a National Year of Reading? An evaluation of the NYR in Yorkshire

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    An evaluation of the National Year of Reading in Yorkshire was conducted by Leeds Metropolitan University in response to a brief from Museums, Libraries and Archives, Yorkshire. This paper outlines the development and planning of phase one of this small scale qualitative research project and the analysis of the initial results which looks at the impact of NYR on the organisations that delivered the campaign and their work with target groups. The Generic Social Outcomes and the National Indicators were used to develop a theoretical framework. Data were gathered via in depth interviews and focus groups with NYR steering group partners in Calderdale and North Lincolnshire, selected as the two case study authorities. The use of MAXQDA computer-assisted qualitative data analysis software (CAQDAS) enabled data and coding structures to be stored and will facilitate comparison in this longitudinal study. This evaluation will provide material that local library authorities can use for advocacy with a range of audiences including local and central government

    Fast iterative solvers for geomechanics in a commercial FE code

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    There is a pressing need to improve the feasibility of three-dimensional finite element (FE) methods applied to many problems in civil engineering. This is particularly the case for static analyses in geotechnical engineering: ideally, models would be 3D, follow the actual geometry, use non-linear material formulations and allow simulation of construction sequences, and all of this with a reasonable degree of accuracy. One major obstacle to improvements in this regard is the difficulty in solving of the set of (linearised) algebraic equations which arises from a typical discretisation approach. Very large systems become cumbersome for direct techniques to solve economically. This paper describes the incorporation of iterative (rather than direct) solution techniques, developed through University research, into commercial FE software for geotechnics

    Localization and its consequences for quantum walk algorithms and quantum communication

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    The exponential speed-up of quantum walks on certain graphs, relative to classical particles diffusing on the same graph, is a striking observation. It has suggested the possibility of new fast quantum algorithms. We point out here that quantum mechanics can also lead, through the phenomenon of localization, to exponential suppression of motion on these graphs (even in the absence of decoherence). In fact, for physical embodiments of graphs, this will be the generic behaviour. It also has implications for proposals for using spin networks, including spin chains, as quantum communication channels.Comment: 4 pages, 1 eps figure. Updated references and cosmetic changes for v

    Phosphoinositide-dependent protein kinase-1 (PDK1)-independent activation of the protein kinase C substrate, protein kinase D

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    Phosphoinoisitide dependent kinase l (PDK1) is proposed to phosphorylate a key threonine residue within the catalytic domain of the protein kinase C (PKC) superfamily that controls the stability and catalytic competence of these kinases. Hence, in PDK1-null embryonic stem cells intracellular levels of PKCalpha, PKCbeta1, PKCgamma, and PKCepsilon are strikingly reduced. Although PDK1-null cells have reduced endogenous PKC levels they are not completely devoid of PKCs and the integrity of downstream PKC effector pathways in the absence of PDK1 has not been determined. In the present report, the PDK1 requirement for controlling the phosphorylation and activity of a well characterised substrate for PKCs, the serine kinase protein kinase D, has been examined. The data show that in embryonic stem cells and thymocytes loss of PDK1 does not prevent PKC-mediated phosphorylation and activation of protein kinase D. These results reveal that loss of PDK1 does not functionally inactivate all PKC-mediated signal transduction

    Magnetic Fields in Star-Forming Molecular Clouds I. The First Polarimetry of OMC-3 in Orion A

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    The first polarimetric images of the OMC-3 region of the Orion A filamentary molecular cloud are presented. Using the JCMT, we have detected polarized thermal emission at 850 microns from dust along a 6' length of the dense filament. The polarization pattern is highly ordered and is aligned with the filament throughout most of the region. The plane-of-sky magnetic field direction is perpendicular to the measured polarization. The mean percentage polarization is 4.2% with a 1 sigma dispersion of 1%. This region is part of the integral-shaped filament, and active star formation is ongoing along its length. The protostellar outflow directions do not appear to be consistently correlated with the direction of the plane-of-sky field or the filament structure itself. Depolarization toward the filament center, previously detected in many other star-forming cores and protostars, is also evident in our data. (abstract abridged)Comment: 9 pages plus 2 figures (1 colour); accepted for publication in the March 10, 2000 issue (vol. 531 #2) of The Astrophysical Journa

    On-demand or Spot? Selling the cloud to risk-averse customers

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    In Amazon EC2, cloud resources are sold through a combination of an on-demand market, in which customers buy resources at a fixed price, and a spot market, in which customers bid for an uncertain supply of excess resources. Standard market environments suggest that an optimal design uses just one type of market. We show the prevalence of a dual market system can be explained by heterogeneous risk attitudes of customers. In our stylized model, we consider unit demand risk-averse bidders. We show the model admits a unique equilibrium, with higher revenue and higher welfare than using only spot markets. Furthermore, as risk aversion increases, the usage of the on-demand market increases. We conclude that risk attitudes are an important factor in cloud resource allocation and should be incorporated into models of cloud markets.Comment: Appeared at WINE 201

    Coherent Time Evolution and Boundary Conditions of Two-Photon Quantum Walks

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    Multi-photon quantum walks in integrated optics are an attractive controlled quantum system, that can mimic less readily accessible quantum systems and exhibit behavior that cannot in general be accurately replicated by classical light without an exponential overhead in resources. The ability to observe time evolution of such systems is important for characterising multi-particle quantum dynamics---notably this includes the effects of boundary conditions for walks in spaces of finite size. Here we demonstrate the coherent evolution of quantum walks of two indistinguishable photons using planar arrays of 21 evanescently coupled waveguides fabricated in silicon oxynitride technology. We compare three time evolutions, that follow closely a model assuming unitary evolution, corresponding to three different lengths of the array---in each case we observe quantum interference features that violate classical predictions. The longest array includes reflecting boundary conditions.Comment: 7 pages,7 figure
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