4,545 research outputs found

    Adjustment of model parameters to estimate distribution transformers remaining lifespan

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    Currently, the electrical system in Argentina is working at its maximum capacity, decreasing the margin between the installed power and demanded consumption, and drastically reducing the service life of transformer substations due to overload (since the margin for summer peaks is small). The advent of the Smart Grids allows electricity distribution companies to apply data analysis techniques to manage resources more efficiently at different levels (avoiding damages, better contingency management, maintenance planning, etc.). The Smart Grids in Argentina progresses slowly due to the high costs involved. In this context, the estimation of the lifespan reduction of distribution transformers is a key tool to efficiently manage human and material resources, maximizing the lifetime of this equipment. Despite the current state of the smart grids, the electricity distribution companies can implement it using the available data. Thermal models provide guidelines for lifespan estimation, but the adjustment to particular conditions, brands, or material quality is done by adjusting parameters. In this work we propose a method to adjust the parameters of a thermal model using Genetic Algorithms, comparing the estimation values of top-oil temperature with measurements from 315 kVA distribution transformers, located in the province of Tucumán, Argentina. The results show that, despite limited data availability, the adjusted model is suitable to implement a transformer monitoring system.Fil: Jimenez, Victor Adrian. Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación en Tecnologías Avanzadas de Tucumán; ArgentinaFil: Will, Adrian L. E.. Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación en Tecnologías Avanzadas de Tucumán; ArgentinaFil: Gotay Sardiñas, Jorge. Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación en Tecnologías Avanzadas de Tucumán; ArgentinaFil: Rodriguez, Sebastian Alberto. Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación en Tecnologías Avanzadas de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentin

    Nonzero solutions of perturbed Hammerstein integral equations with deviated arguments and applications

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    We provide a theory to establish the existence of nonzero solutions of perturbed Hammerstein integral equations with deviated arguments, being our main ingredient the theory of fixed point index. Our approach is fairly general and covers a variety of cases. We apply our results to a periodic boundary value problem with reflections and to a thermostat problem. In the case of reflections we also discuss the optimality of some constants that occur in our theory. Some examples are presented to illustrate the theory.Comment: 3 figures, 23 page

    Haematobia irritans clone Hi-18S-ab-fr 18S ribosomal RNA gene, partial sequence

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    GenBank: EU013947.1 Haematobia irritans clone Hi-18S-ab-fr 18S ribosomal RNA gene, partial sequenceFil: Sonvico, A.. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Filiberti, Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Quesada Allue, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

    A fuzzy multiobjective algorithm for multiproduct batch plant: Application to protein production

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    This paper addresses the problem of the optimal design of batch plants with imprecise demands and proposes an alternative treatment of the imprecision by using fuzzy concepts. For this purpose, we extended a multiobjective genetic algorithm (MOGA) developed in previousworks, taking into account simultaneously maximization of the net present value (NPV) and two other performance criteria, i.e. the production delay/advance and a flexibility criterion. The former is computed by comparing the fuzzy computed production time to a given fuzzy production time horizon and the latter is based on the additional fuzzy demand that the plant is able to produce. The methodology provides a set of scenarios that are helpful to the decision’s maker and constitutes a very promising framework for taken imprecision into account in new product development stage

    Multiobjective Multiproduct Batch Plant Design Under Uncertainty

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    This paper addresses the problem of the optimal design of batch plants with imprecise demands and proposes an alternative treatment of the imprecision by using fuzzy concepts. For this purpose, we extended a multiobjective genetic algorithm developed in previous works, taking into account simultaneously maximization of the net present value (NPV) and two other performance criteria, i.e. the production delay/advance and a flexibility criterion. The former is computed by comparing the fuzzy computed production time to a given fuzzy production time horizon and the latter is based on the additional fuzzy demand that the plant is able to produce. The methodology provides a set of scenarios that are helpful to the decision’s maker and constitutes a very promising framework for taken imprecision into account in new product development stage

    Representations of Gay Men in Contemporary Spanish Cinema

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    The aim of this thesis is to offer a diverse perspective on the representation and conceptualisation of male homosexuality in Spanish cinema over the past twenty years. Key questions considered include: how is male homosexuality represented on screen? With what particularities and ideological inflections has Spanish cinema categorised gay male characters? What is included and excluded in such representations? What do these representations say about Spanish society? Also, how are those representations related to the past – and, possibly, the future? National cinema is invariably shaped by, and in turn shapes, the social, political, and legal contexts in which it is forged, and Spain’s cinematic traditions are no exception. The aim of this thesis is to explore the interrelationships between Spanish film conventions and changing legal, discursive, and visual frameworks. The thesis explores the interrelationships between these frameworks and focuses on three thematic areas: Space, Body, and Family. In Queer Spaces I analyse the representation of Madrid’s gay district Chueca in Spanish cinema over the last two decades, and how it has evolved from an underground and liminal area of jouissance in the 1980s and early 1990s to a commercialised and globalised ‘village’ in the 2000s. I also examine how films subvert those binary oppositions often associated with space, such as hetero/homo, local/global or private/public. Gay Male Bodies focuses on the medicalisation of the male gay body and the discourse of homosexuality as ‘the other:’ I discuss how discourses that originated in Spain during Franco’s regime can still be seen in some contemporary films, and what this means for the progressive representation of male homosexuality on screen. The final section, Same-Sex Families, questions the notion of ‘family’ and ‘family values’ in regard to gay characters, and I consider key issues in contemporary GLBT politics, including gay marriage, gay families, gay adoption and the relationships between gay and heterosexual family members

    On-board real-time pose estimation for UAVs using deformable visual contour registration

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    Presentado al ICRA 2014 celebrado en Hong Kong del 31 de mayo al 7 de junio.We present a real time algorithm for estimating the pose of non-planar objects on which we have placed a visual marker. It is designed to overcome the limitations of small aerial robots, such as slow CPUs, low image resolution and geometric distortions produced by wide angle lenses or viewpoint changes. The method initially registers the shape of a known marker to the contours extracted in an image. For this purpose, and in contrast to state-of-the art, we do not seek to match textured patches or points of interest. Instead, we optimize a geometric alignment cost computed directly from raw polygonal representations of the observed regions using very simple and efficient clipping algorithms. Further speed is achieved by performing the optimization in the polygon representation space, avoiding the need of 2D image processing operations. Deformation modes are easily included in the optimization scheme, allowing an accurate registration of different markers attached to curved surfaces using a single deformable prototype. Once this initial registration is solved, the object pose is retrieved using a standard PnP approach. As a result, the method achieves accurate object pose estimation in real-time, which is very important for interactive UAV tasks, for example for short distance surveillance or bar assembly. We present experiments where our method yields, at about 30Hz, an average error of less than 5mm in estimating the position of a 19×19mm marker placed at 0.7m of the camera.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness under project TaskCoop DPI2010-17112, by the ERANet Chistera project ViSen PCIN-2013-047 and by the EU project ARCAS FP7-ICT-2011-28761. A. Ruiz is supported by FEDER funds under grant TIN2012-38341-C04-03.Peer Reviewe

    Modeling Programming Language Trends Using Markov Processes

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    Which Languages Are Worth Investing In? One of the many issues in the computer science industry is knowing which technologies to invest in. Programming languages are a prime example of these technologies, so investors and innovators need to know which programming languages will grow in use over time so that new businesses can grow alongside them
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