22,251 research outputs found

    The Role of the Manufacturer in Air Transportation Planning

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    The role of the aircraft manufacturer in the airline industry is considered. The process is illustrated by using a fictitious airline as an example--that is, a case study approach with Mid-Coast Airways serving as the example. Both in slide form and with supporting papers, a brief history of the airline, a description of its route structure and a forecast based on econometric analysis are presented. Once the forecast rationale is explained, information outlines the requirements for additional aircraft and the application of new aircraft across the system using alternative fleet plan options. The fleet plan is translated into financial summaries which indicate the relative merit of alternative aircraft types or operating plans

    Changing academic practice at a UK research-intensive university through supporting the scholarship of teaching and learning (SoTL)

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    Over the past decade, there have been many changes in Higher Education in the UK. Alongside increased student participation and widening access, the government has called for universities to professionally develop teachers in Higher Education and recognise the role of learning and teaching in the sector. The University of Glasgow has responded to this changing agenda in a number of ways. At the institutional level, the University launched its first comprehensive Learning and Teaching Strategy in 2006. At the same time it also appointed Associate Deans of Learning and Teaching in each Faculty. Another initiative has been the introduction of a ‘teaching’ career track, through the establishment of a new category of academic staff, the University Teacher, with promotion procedures supporting career development up to Professorial level. Rather than engaging in research (one of the main academic roles of the lecturer, associate professor in US terms), University Teachers must engage in scholarship, in addition to their teaching and administration duties. The establishment of a Learning and Teaching Centre responsible for supporting the University in the implementation of its Learning and Teaching Strategy has also consolidated and initiated a number of activities that all aim to enhance the Scholarship of Teaching and Learning at Glasgow. These initiatives have wrought changes at an institutional level and are contributing to changing academic practice. In particular, the term ‘Scholarship of Teaching and Learning’, once unheard of at the institution is increasingly being recognised as a valid form of academic activity and increasing numbers of academic staff are engaging in it. This paper will outline some of these changes and offer reflections on their impact on SoTL and academic practice

    Photoconductivity and phototropy in non-crystalline solids

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    Photoconductivity and phototropy in noncrystalline solid

    Holistic finite differences accurately model the dynamics of the Kuramoto-Sivashinsky equation

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    We analyse the nonlinear Kuramoto-Sivashinsky equation to develop an accurate finite difference approximation to its dynamics. The analysis is based upon centre manifold theory so we are assured that the finite difference model accurately models the dynamics and may be constructed systematically. The theory is applied after dividing the physical domain into small elements by introducing insulating internal boundaries which are later removed. The Kuramoto-Sivashinsky equation is used as an example to show how holistic finite differences may be applied to fourth order, nonlinear, spatio-temporal dynamical systems. This novel centre manifold approach is holistic in the sense that it treats the dynamical equations as a whole, not just as the sum of separate terms

    Accurate macroscale modelling of spatial dynamics in multiple dimensions

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    Developments in dynamical systems theory provides new support for the macroscale modelling of pdes and other microscale systems such as Lattice Boltzmann, Monte Carlo or Molecular Dynamics simulators. By systematically resolving subgrid microscale dynamics the dynamical systems approach constructs accurate closures of macroscale discretisations of the microscale system. Here we specifically explore reaction-diffusion problems in two spatial dimensions as a prototype of generic systems in multiple dimensions. Our approach unifies into one the modelling of systems by a type of finite elements, and the `equation free' macroscale modelling of microscale simulators efficiently executing only on small patches of the spatial domain. Centre manifold theory ensures that a closed model exist on the macroscale grid, is emergent, and is systematically approximated. Dividing space either into overlapping finite elements or into spatially separated small patches, the specially crafted inter-element/patch coupling also ensures that the constructed discretisations are consistent with the microscale system/PDE to as high an order as desired. Computer algebra handles the considerable algebraic details as seen in the specific application to the Ginzburg--Landau PDE. However, higher order models in multiple dimensions require a mixed numerical and algebraic approach that is also developed. The modelling here may be straightforwardly adapted to a wide class of reaction-diffusion PDEs and lattice equations in multiple space dimensions. When applied to patches of microscopic simulations our coupling conditions promise efficient macroscale simulation.Comment: some figures with 3D interaction when viewed in Acrobat Reader. arXiv admin note: substantial text overlap with arXiv:0904.085

    Simulation of the small punch creep test with consideration of variation of material properties

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    A new finite element model of the small punch creep test is described. The material constitutive relationship for creep considered is a simple Norton power law: in this study the exponent in the power law is varied for each element to simulate the random behaviour of creep. The influence of this random variation, and the effect of the friction factor between the punch and specimen, on the deformation and stress field has been investigated

    Identification of Uncommon Non-crystalline Solids as ''real'' Glasses

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    Identification of uncommon noncrystalline solids as real glasse

    Metamodelling of multivariable engine models for real-time flight simulation.

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    Sophisticated real-time distributed flight simulation environments may be constructed from a wide range of modelling and simulation tools. In this way accuracy, detail and model flexibility may be incorporated into the simulator. Distributed components may be constructed by a wide range of methods, from high level environments such as Matlab, through coded environments such as C or Fortran to hardware-in-the- loop. In this paper the Response Surface Methodology is combined with a hyper-heuristic (evolutionary algorithm) and applied to the representation of computationally intensive non-linear multivariable engine modelling. The paper investigates the potential for metamodelling (models of models) dynamic models which were previously too slow to be included in multi-component, high resolution real-time simulation environments. A multi-dimensional gas turbine model with five primary control inputs, six environmental inputs and eleven outputs is considered. An investigation has been conducted to ascertain to what extent these systems can be approximated by response surfaces with experiments which have been designed by hyper-heuristics as a first step towards automatic modelling methodology

    Elastic stress concentration at radial crossholes in pressurised thick cylinders

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    Results of a parametric finite element analysis investigation of stress concentration at radial crossholes in pressurized cylinders are presented in numerical and graphical form. The analysis shows that the location of maximum stress does not generally occur at the junction between the bores, as is commonly supposed, but at some small distance up the crosshole from the junction. Maximum stress concentration factors (SCFs) are defined on the basis of the maximum principal stress, von Mises equivalent stress, and stress intensity. Three-dimensional plots of the SCF against the cylinder radius ratio b/a and the crosshole-to-main-bore-radius ratio c/a are presented. The SCFs were found to vary across the range of geometries considered with local minima identified within the parameter range in most cases. The results therefore allow designers to select optimum b/a and c/a ratios to minimize stress concentration in real problems
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