1,222 research outputs found

    «Sernac con Farmacias Ahumada S.A.»: Un acercamiento a la responsabilidad postcontractual en materia de consumo

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    Este comentario trata la sentencia recaída en la causa Sernac con Farmacias Ahumada S.A., referente a la responsabilidad de la empresa derivada de la Ley del Consumidor, una vez que reconoció su participación en una colusión de precios. Se aborda primeramente el ámbito de aplicación de la Ley de Protección de los Derechos de los Consumidores, proponiéndose a la relación de consumo como criterio de aplicabilidad. En segundo término se analiza el caso a partir de la responsabilidad post contractual, señalándose que ella sí procede, con fundamento en la buena fe. Se concluye también que la responsabilidad postcontractual se rige por el estatuto contractual

    AVIAN SPECIATION IN THE PANTEPUI: THE CASE OF THE RORAIMAN ANTBIRD (PERCNOSTOLA [SCHISTOCICHLA] ‘‘LEUCOSTIGMA’’ SATURATA)

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    This is the published version. Copyright Central Ornithology Publication OfficeWe document the first records for Guyana of Roraiman Antbird (Percnostola [Schistocichla] “leucostigma” saturata), an endemic of the tepui highlands of southeastern Venezuela, northern Brazil and western Guyana. This form is well differentiated from nominate leucostigma (Spot-winged Antbird) of the Guianan lowlands in morphology, vocalizations, and genetics, and replaces it both altitudinally and ecologically. The two taxa are distributed parapatrically on the continuously forested northeastern slopes of the eastern tepuis, and they almost certainly come into contact, yet there is no evidence of intermediacy. We recommend that saturata be treated as a distinct species of Percnostola, and consider its' origin in the light of various models of speciation in the tepuis

    Applying virtual reality to teach the software development process to novice software engineers

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    Software development is a complicated process that requires experienced human resources to produce successful software products. Although this process needs experience from the individuals, it is hard to provide this experience without encountering real incidents during the software development process. To fill this gap, this study proposes a Virtual Reality Based Software Development Framework (VR-SODEF), which provides an interactive virtual reality experience for individuals learning about the tasks of software development starting from requirement analysis through software testing. In the VR-SODEF, the participant takes on the role of a novice software developer being recruited into a virtual software development organisation who should work alongside five virtual characters, played by artificial intelligence. This exclusive viewpoint draws participants from the 2D separation of the classical experience and virtually into the world of the software development itself. Participants experience the intense dramatic elements created for simulation and confront the challenges of virtual software practitioners in a somewhat uncompromising virtual simulation environment. To examine the efficiency of the VR-SODEF, it was tested on 32 computing students, with results indicating that virtual reality can be an effective educational medium, especially for skills that might traditionally be acquired through experience rather than traditional classroom-based teaching

    Superconductors with Topological Order

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    We propose a mechanism of superconductivity in which the order of the ground state does not arise from the usual Landau mechanism of spontaneous symmetry breaking but is rather of topological origin. The low-energy effective theory is formulated in terms of emerging gauge fields rather than a local order parameter and the ground state is degenerate on topologically non-trivial manifolds. The simplest example of this mechanism of superconductivty is concretely realized as global superconductivty in Josephson junction arrays.Comment: 4 pages, no figure

    Nektar++: Development of the Compressible Flow Solver for Large Scale Aeroacoustic Applications

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    A recently developed computational framework for jet noise predictions is presented. The framework consists of two main components, focusing on source prediction and noise propagation. To compute the noise sources, the turbulent jet is simulated using the compressible flow solver implemented in the open-source spectral/hp element framework Nektar++, which solves the unfiltered Navier-Stokes equations on unstructured grids using the high- order discontinuous Galerkin method. This allows high-order accuracy to be achieved on unstructured grids, which in turn is important in order to accu- rately simulate industrially relevant geometries. For noise propagation, the Ffowcs Williams - Hawkings method is used to propagate the noise between the jet and the far-field. The paper provides a detailed description of the com- putational framework, including how the different components fit together and how to use them. To demonstrate the framework, two configurations of a single stream subsonic jet are considered. In the first configuration, the jet is treated in isolation, whereas in the second configuration, it is installed under a wing. The aerodynamic results for these two jets show strong agreement with experimental data, while some discrepancies are observed in the acous- tic results, which are discussed. In addition to this, we demonstrate close to linear scaling beyond 100, 000 processors on the ARCHER2 supercomputer

    System Identification and Control of Front-Steered Ackermann Vehicles through Differentiable Physics

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    In this paper, we address the problem of system identification and control of a front-steered vehicle which abides by the Ackermann geometry constraints. This problem arises naturally for on-road and off-road vehicles that require reliable system identification and basic feedback controllers for various applications such as lane keeping and way-point navigation. Traditional system identification requires expensive equipment and is time consuming. In this work we explore the use of differentiable physics for system identification and controller design and make the following contributions: i)We develop a differentiable physics simulator (DPS) to provide a method for the system identification of front-steered class of vehicles whose system parameters are learned using a gradient-based method; ii) We provide results for our gradient-based method that exhibit better sample efficiency in comparison to other gradient-free methods; iii) We validate the learned system parameters by implementing a feedback controller to demonstrate stable lane keeping performance on a real front-steered vehicle, the F1TENTH; iv) Further, we provide results exhibiting comparable lane keeping behavior for system parameters learned using our gradient-based method with lane keeping behavior of the actual system parameters of the F1TENTH.Comment: Accepted for IROS 202
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