811 research outputs found

    Electrodynamics of quasi-two-dimensional BEDT-TTF charge transfer salts

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    We consider the millimeter-wave electrodynamics specific to quasi-two-dimensional conductors and superconductors based on the organic donor molecule BEDT-TTF. Using realistic physical parameters, we examine the current polarizations that result for different oscillating (GHz) electric and magnetic field polarizations. We show that, in general, it is possible to discriminate between effects (dissipation and dispersion) due to in-plane and interlayer ac currents. However, we also show that it is not possible to selectively probe any single component of the in-plane conductivity tensor, and that excitation of interlayer currents is strongly influenced by the sample geometry and the electromagnetic field polarization.Comment: 5 pages including 3 figures Minor correction to figure

    E-commerce and e-procurement: an outsourcing perspective

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    The make or buy dilemma has been largely analyzed in the field of Information Systems. The main reason for this type of literature thriving so much is that the Information Systems function was one of the first enterprise areas to be externalized. If traditionally only few activities, distant from the core business of the enterprises, have been externalized with the sole objective of gaining efficiency, in the late Nineties externalization of real company functions has started to be considered again, in some instances concerning activities that have always been considered core business. The role played by the management of organizational interdependencies was stressed and the fact that outsourcing was perceived according to solutions of organizational engineering was highlighted, steering enterprises towards new organizational design criteria. In fact, make or buy decisions require more and more that organizational variables be structured by processes and not by functions, precisely to ease the management of organizational interdependencies and make externalization decisions more transparent and objectively measurable. The research question of this paper aims at understanding how much can a particular form of electronic commerce, such as e-procurement, be categorized as a special form of outsourcing, intending this phenomenon as a hybrid organizational form, halfway between hierarchy and market. In order to categorize the outsourcing phenomenon from a theoretical standpoint, the Transaction Cost Theory (TCT) has been used, while the research method consists of a case study. In this paper the attention will be focused on a particular process only, i.e., procurement, in relation to the activities involved in the externalization process. The paper will analyze an outsourcing case applied to the entire macro-process of procurement. The conclusions will highlight the evolving trends in this research field, which appears to be affected by substantial changes and to be increasingly more volatile and influenced by multiple factors that are not always easily recognizable and measurable. The purpose of this paper in fact is to give a contribution to the formalization of an application subject, namely, externalization of procurement, largely diffused in practice although scarcely developed from a theoretical standpoint

    Enhancing CFD predictions in shape design problems by model and parameter space reduction

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    In this work we present an advanced computational pipeline for the approximation and prediction of the lift coefficient of a parametrized airfoil profile. The non-intrusive reduced order method is based on dynamic mode decomposition (DMD) and it is coupled with dynamic active subspaces (DyAS) to enhance the future state prediction of the target function and reduce the parameter space dimensionality. The pipeline is based on high-fidelity simulations carried out by the application of finite volume method for turbulent flows, and automatic mesh morphing through radial basis functions interpolation technique. The proposed pipeline is able to save 1/3 of the overall computational resources thanks to the application of DMD. Moreover exploiting DyAS and performing the regression on a lower dimensional space results in the reduction of the relative error in the approximation of the time-varying lift coefficient by a factor 2 with respect to using only the DMD

    Enhancing CFD predictions in shape design problems by model and parameter space reduction

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    In this work we present an advanced computational pipeline for the approximation and prediction of the lift coefficient of a parametrized airfoil profile. The non-intrusive reduced order method is based on dynamic mode decomposition (DMD) and it is coupled with dynamic active subspaces (DyAS) to enhance the future state prediction of the target function and reduce the parameter space dimensionality. The pipeline is based on high-fidelity simulations carried out by the application of finite volume method for turbulent flows, and automatic mesh morphing through radial basis functions interpolation technique. The proposed pipeline is able to save 1/3 of the overall computational resources thanks to the application of DMD. Moreover exploiting DyAS and performing the regression on a lower dimensional space results in the reduction of the relative error in the approximation of the time-varying lift coefficient by a factor 2 with respect to using only the DMD

    Squamous Cell Carcinoma and Ledderhose Disease: A Case Report

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    Ledderhose disease is disorder of the plantar aponeurosis. This disease is not so common and can be tackled with a surgical or conservative approach. A case of a 73-year-old man came to our attention who had a 26-year history of painless bilateral plantar nodules coalescing into an indurated mass. An ulcerative nodule had been noted in the last 16 months on the right foot, in the absence of trauma, not responsive to conservative treatment, so we decided to perform a biopsy. The histopatologic examination showed squamous cell carcinoma, with warty, well-differentiated, low-grade malignancy. Surgical treatment was suggested, so, in pneumoischemia, we made a surgical incision including the skin lesion. Then we proceeded to sculpture the anterolateral thigh fasciacutaneous flap to obtain adequate soft tissue coverage. The tumor was completely removed. Current reconstructive possibilities comprise a good anatomofunctional recovery even in the case of large demolition requests for the therapy of advanced cases of the disease described in this article. Correlation between Ledderhose disease and the formation of malignant tumors has not been made as yet, but perhaps an element that could unite these pathologies can be researched in the lively cell proliferation that characterizes both. It would be interesting to analyze the biological substrate, as well as the systemic and local levels, in patients where both diseases are manifested

    BI as a service: an attempt to understand the leading adoption factors

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    The research question of this study attempts to identify which are the leading factors for the adoption of a sourcing Software as a Service model for Business Intelligence applications. The objective is to build a model containing enabling factors for the adoption of BI solutions. We seek to expand on the Benlian et al. model which is based on a theoretical framework including axioms from Transaction Cost Theory, Resource Based View, Theory of Planned Behavior. In order to better understand the phenomenon under investigation, we will use also the Organizational Culture Theory. It is a theoretical research in progress
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