A Markovian jump system approach for the estimation and adaptive diagnosis of decreased power generation in wind farms

In this study, a Markovian jump model of the power generation system of a wind turbine is proposed and the authors present a closed-loop model-based observer to estimate the faults related to energy losses. The observer is designed through an H∞-based optimisation problem that optimally fixes the trade-off between the observer fault sensitivity and robustness. The fault estimates are then used in data-based decision mechanisms for achieving fault detection and isolation. The performance of the strategy is then ameliorated in a wind farm (WF) level scheme that uses a bank of the aforementioned observers and decision mechanisms. Finally, the proposed approach is tested using a well-known benchmark in the context of WF fault diagnosis

El dilema del prisionero y la cooperación

Este trabajo hace un resumen de lo que es el dilema del prisionero y por que presenta un dilema. Para ello se explica lo que es la teoría de juegos y sus componentes, además de las diferentes formas de solucionar el juego. Se habla también de los juegos repetidos en los que por primera vez el dilema del prisionero cambia su solución. Como conclusión se da una opinión personal basada en el trabajo en su conjunto.Departamento de Economía AplicadaGrado en Administración y Dirección de Empresa

Towards an open and user driven housing architecture: layers principle, infrastructure types and technical devices

Peer Reviewe

Towards an open and user driven housing architecture: layers principle, infrastructure types and technical devices

Peer Reviewe

Inmigración y valores : su impacto en la intervención social

La Encuesta de Valores, que viene realizándose periódicamente desde los años 80, plantea algunas preguntas acerca de los inmigrantes, la actitud de la población hacia ellos, los valores que están detrás de la integración de los inmigrantes, etc. Esta comunicación analiza los datos de la última encuesta de 1999-2000 y muestra los diferentes tipos de valores que se detectan entre la población, en relación con los inmigrantes; el modelo de integración que se plantea referente a los extranjeros, y la solidaridad o rechazo existente frente al fenómeno migratorio. Todo ello, desde una perspectiva comparativa entre los países de la Unión Europea. También se examina la relación entre los valores existentes y el tipo de intervención social a desarrollar.The European Values Survey which has been done periodically since the 80s makes some questions about the immigrants: the attitudes of the population towards them, the values that are behind the integration of the immigrants,.... This paper analyses the results from the last Survey of 1999-2000, and shows, in a comparative european perspective, the different type of values related with the immigrants, the integration model that can be carried out with the immigrants and the solidarity or rejection with the migratory phenomenon. It also studies the relation between the existing values and the type of social work that can be developed

El FRAP entra en escena (mayo de 1973). Discursos, mensajes y opiniones en la prensa de la época.

Sin resume

Robust estimation and diagnosis of wind turbine pitch misalignments at a wind farm level

Wind turbine pitch misalignments provoke aerodynamic asymmetries which cause severe damage to the turbine. Hence, it is of interest to develop fault tolerant strategies to cope with pitch misalignments. Fault tolerant strategies require the information regarding the diagnosis and the estimation of the faults. However, most existing works focus only on open-loop misalignment diagnosis and do not provide robust fault estimates. In this work, we present a novel strategy to both estimate and diagnose pitch misalignments. The proposed strategy is developed at a wind farm level and it exploits altogether the information provided by the temporal and spatial relations of the turbines in the farm. Fault estimation is first addressed with a closed-loop switched observer. This observer is robust against disturbances and it adapts to the varying conditions along the wind turbine operation range. Fault diagnosis is then achieved via statistical-based decision mechanisms with adaptive thresholds. Both the observer and the decision mechanisms are designed to guarantee the desired performance. Introducing some restrictions over the number of simultaneous faulty turbines in the farm, the proposed approach is ameliorated via a bank of the aforementioned observers and decision mechanisms. Finally, the strategies are tested using a well-known wind farm benchmark

The teaching-learning process in ubiquitous and university contexts: three case studies

En este trabajo se pretende identificar los componentes del proceso de enseñanza-aprendizaje de lenguas extranjeras que mejor se adapten a diferentes entornos educativos- ya sea presencial u online- con el objetivo de observar cómo la optimización de diferentes estrategias metodológicas puede resultar en la optimización del aprendizaje. Para este propósito, identificamos la construcción de ambientes de aprendizaje que se han llevado a cabo, por un lado, en un entorno on line (Universidade Alberta) y, por otro, en uno presencial enriquecido digitalmente (Universidade Catolica Portuguesa). De esta manera, proponemos un diseño metodológico basado en la adaptabilidad tanto de los componentes cognitivos de los alumnos como del contexto en el que se produce el aprendizaje. Se apuesta a la diversificación no sólo de contenidos, sino también de las diferentes maneras de entender el aprendizaje.In this article, we aim to identify the components of the learning-teaching process for foreign languages that better adapt themselves to different teaching environments (face-to-face and online) with the objective of observing how the optimization of different methodological strategies can result in the optimization of learning. Likewise, we will identify some of the learning environmental constructions that have been carried out in a completely “online” environment (Universidade Aberta) as well as in a face-to-face but digitally enriched context (Universidade Católica Portuguesa).In this way, we propose a methodological design based on the adaptability of both the cognitive components of the students and the context in which learning takes place. It is committed to the diversification not only of contents, but also of the different ways of understanding learning.info:eu-repo/semantics/publishedVersio

Trade-offs on fault estimation via proportional multiple-integral and multiple-resonant observers for discrete-time systems

The authors develop a fault estimation strategy which is based on a novel proportional multiple-integral (PMI) and multiple-resonant observer. This observer is an extension of the well-known PMI observer and it is able to estimate from low to high-frequency fault signals. The proposed estimation strategy is applied to discrete-time systems which are affected by faults and stochastic noises. We present a multi-objective design strategy of the observer that fixes the trade-offs between practical engineering parameters regarding the noise attenuation and the ability to track each kind of fault dynamics considered by the augmented observer. They study the influence of the order of the observer on the steady-state and transient performance of the estimation of different types of faults. Finally, a numerical example is given to illustrate the effectiveness of the proposed observer, design and characterisation

Cuidadores de ancianos dependientes : demandas y estrategias de apoyo

La figura del cuidador está adquiriendo una importancia creciente en una sociedad envejecida. Su participación está siendo fundamental para que sus familiares ancianos -especialmente los más débiles-, permanezcan en su entorno con una calidad de vida aceptable. Por ello, es necesario que desde la sociedad se conozca su realidad, con el fin de realizar acciones de apoyo que les permitan continuar con su labor, para cuidar a los cuidadores. Esta comunicación tiene su base en una investigación realizada recientemente sobre la situación y demandas de atención por parte de los familiares cuidadores de ancianos dependientes que viven en su propio domicilio. Tras presentar un perfil de los cuidadores -mejor habría que decir cuidadoras-, se profundizará en las líneas maestras que deben de guiar la actuación de las políticas sociales para mantener su implicación y desarrollar su participación. Para ello se analiza la opinión de los propios cuidadores, los profesionales de atención directa y los gestores de los servicios sociales.The role of the careers is acquiring an increasing importance in an aged society. Their participation is essential so that their elderly relatives - specially the weakest-, may remain in their own environment with an acceptable life quality. For this reason, the society needs to know their reality, in order to carry out support actions that may allow them to continue with their work, to take care of the elderly care givers. This communication is based on recent investigation studying the situation and demands of attention from the relatives of the elderly careers that take care of of dependent elders who live in their own home. After presenting a profile of the elderly care givers – mostly women-, will explain the main guidelines that must be considered so that the social policys may keep their implication and increase their participation. It will be analyzed the opinion of the elderly care givers themselves, the professionals who offer direct assistance, and the managers of the social services