28 resultados para Classification--History--Sources


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Demand response can play a very relevant role in the context of power systems with an intensive use of distributed energy resources, from which renewable intermittent sources are a significant part. More active consumers participation can help improving the system reliability and decrease or defer the required investments. Demand response adequate use and management is even more important in competitive electricity markets. However, experience shows difficulties to make demand response be adequately used in this context, showing the need of research work in this area. The most important difficulties seem to be caused by inadequate business models and by inadequate demand response programs management. This paper contributes to developing methodologies and a computational infrastructure able to provide the involved players with adequate decision support on demand response programs and contracts design and use. The presented work uses DemSi, a demand response simulator that has been developed by the authors to simulate demand response actions and programs, which includes realistic power system simulation. It includes an optimization module for the application of demand response programs and contracts using deterministic and metaheuristic approaches. The proposed methodology is an important improvement in the simulator while providing adequate tools for demand response programs adoption by the involved players. A machine learning method based on clustering and classification techniques, resulting in a rule base concerning DR programs and contracts use, is also used. A case study concerning the use of demand response in an incident situation is presented.

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In the present paper we assess the performance of information-theoretic inspired risks functionals in multilayer perceptrons with reference to the two most popular ones, Mean Square Error and Cross-Entropy. The information-theoretic inspired risks, recently proposed, are: HS and HR2 are, respectively, the Shannon and quadratic Rényi entropies of the error; ZED is a risk reflecting the error density at zero errors; EXP is a generalized exponential risk, able to mimic a wide variety of risk functionals, including the information-thoeretic ones. The experiments were carried out with multilayer perceptrons on 35 public real-world datasets. All experiments were performed according to the same protocol. The statistical tests applied to the experimental results showed that the ubiquitous mean square error was the less interesting risk functional to be used by multilayer perceptrons. Namely, mean square error never achieved a significantly better classification performance than competing risks. Cross-entropy and EXP were the risks found by several tests to be significantly better than their competitors. Counts of significantly better and worse risks have also shown the usefulness of HS and HR2 for some datasets.

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La biblioteca escolar es un servicio de información básico para todos los miembros de una comunidad educativa, que forma parte de los espacios docentes de los centros y de los procesos pedagógicos que tienen lugar en ellos. Las bibliotecas escolares funcionan como centros de recursos para las actividades de enseñanza-aprendizaje, están constituidas por un conjunto sistematizado y dinámico de servicios y fondos documentales que permiten a los usuarios desarrollar hábitos lectores y buscar y valorar las fuentes de información, entre otras relevantes funciones. Los recursos de información que albergan son uno de sus principales activos, pero si colección documental no está organizada, las tareas de búsqueda y localización de la información resultarán complicadas y la calidad de los recursos obtenidos, cuestionable. Los bibliotecarios deben conocer en profundidad las características específicas del fondo documental y las fuentes disponibles; las técnicas y herramientas adecuadas para procesar y tratar el fondo bibliográfico, así como los métodos de recuperación de la información más convenientes. En este contexto, el objetivo de este trabajo es analizar de forma pormenorizada los procesos de indización y clasificación que se realizan en las bibliotecas escolares para procesar y recuperar la información que albergan su colecciones, así como describir las características más relevantes de las herramientas específicas que se usan en las bibliotecas escolares españolas, brasileñas y portuguesas, adaptadas a las características de los usuarios que utilizan sus servicios y acuden a ellas para resolver necesidades de información. Para lograr este propósito, se analiza el concepto de biblioteca escolar de forma crítica, se estudian sus funciones y se examinan las técnicas y los instrumentos que permiten organizar la información. Entre otras herramientas, se estudian listas de encabezamientos de materia como los Encabezamientos de materia para libros infantiles y juveniles y la Lista de Encabezamientos de materia para las bibliotecas públicas; sistemas de clasificación, como la Clasificación Decimal Universal (edición de bolsillo) o la clasificación por centros de interés y tesauros especializados como el Tesauro de la Educación UNESCO-OIE y el Tesauro Europeo de la Educación, entre otros.

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O desenvolvimento sustentável é um dos grandes desafios dos nossos tempos com inúmeras consequências em várias áreas da nossa sociedade. É uma questão abrangente e essencial para a sobrevivência do modo de vida tal como o conhecemos actualmente. A construção sustentável tem um papel muito importante no desenvolvimento, não só ao nível económico mas também social e cultural. Embora não contemple a energia incorporada, a avaliação do ciclo de vida (ACV), no sector da construção, é um dos métodos mais comuns para avaliar o nível de sustentabilidade. Este trabalho visa os metais como uma das mais promissoras e actuais respostas do sector da construção às crescentes preocupações em relação ao desenvolvimento sustentável. O ferro e derivados são normalmente a base das construções metálicas, residindo no seu potencial de reutilização e reciclagem um dos seus principais factores de sustentabilidade. As estruturas metálicas apresentam características especificas que se coadunam com os requisitos da construção sustentável e que tornam este tipo de construção extremamente versátil e interessante. Neste trabalho, é efectuada uma abordagem sobre a construção metálica ao longo de três partes. A primeira parte é constituída por uma introdução histórica ao ferro e seus derivados enunciando exemplos de construções até aos nossos dias, e pela classificação dos vários tipos de metais e ligas metálicas. Na segunda parte, é abordado o conceito de sustentável e o seu enquadramento no sector da construção, e é feita uma introdução à metodologia de avaliação de ciclo de vida. Na terceira parte, é abordado um exemplo prático de uma estrutura metálica em que são elaboradas e comparadas três soluções. Na origem da diversidade dos elementos comparativos estão o tipo de aço, a origem da energia utilizada no seu fabrico e o tipo de solução técnica adoptada. O objectivo deste trabalho é compreender as repercussões do conceito de sustentabilidade no sector da construção, e desenvolver um método simplificado de avaliação dos impactos ambientais e económicos de soluções metálicas.

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Scientific research seminar within CICE mini summer school 25 june

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Atualmente, os guias turísticos são constituídos por diversos módulos, nomeadamente, módulos de recomendação e de modelação do utilizador. Estes ajudam a adaptar melhor as recomendações dadas ao utilizador de acordo com as suas preferências. A necessidade de adaptar os guias turísticos às possíveis necessidades de saúde do utilizador, foi a motivação para a realização desta dissertação. Quando alguém visita um local desconhecido, considera normalmente as condições tanto de alojamento como de alimentação desse local. Contudo, se por algum motivo, necessita de cuidados de saúde, essa pessoa não se encontra preparada para isso. Assim, a recomendação de uma instituição de saúde direcionada para o turista é uma solução possível para o problema encontrado. Pretendeu-se desenvolver um módulo de recomendação híbrido no âmbito da prestação de informações relacionadas com as possíveis necessidades de saúde do turista, tendo em conta o seu perfil. Para a sua implementação seguiu-se a abordagem baseada em conteúdo e técnicas de classificação das instituições de saúde a recomendar ao utilizador. O protótipo desenvolvido foi testado com alguns utilizadores em termos de funcionalidades. Finalmente, pretende-se que o protótipo seja testado com mais utilizadores, possuidores de diversas características em termos de condições de mobilidade, historial clínico e necessidades. Estes testes irão permitir avaliar o protótipo ao nível da qualidade da recomendação prestada. Poder-se-á, assim, atingir o objetivo relativo à integração deste protótipo num sistema de recomendação de apoio ao turista utilizado pela Câmara Municipal do Porto.

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Near real time media content personalisation is nowadays a major challenge involving media content sources, distributors and viewers. This paper describes an approach to seamless recommendation, negotiation and transaction of personalised media content. It adopts an integrated view of the problem by proposing, on the business-to-business (B2B) side, a brokerage platform to negotiate the media items on behalf of the media content distributors and sources, providing viewers, on the business-to-consumer (B2C) side, with a personalised electronic programme guide (EPG) containing the set of recommended items after negotiation. In this setup, when a viewer connects, the distributor looks up and invites sources to negotiate the contents of the viewer personal EPG. The proposed multi-agent brokerage platform is structured in four layers, modelling the registration, service agreement, partner lookup, invitation as well as item recommendation, negotiation and transaction stages of the B2B processes. The recommendation service is a rule-based switch hybrid filter, including six collaborative and two content-based filters. The rule-based system selects, at runtime, the filter(s) to apply as well as the final set of recommendations to present. The filter selection is based on the data available, ranging from the history of items watched to the ratings and/or tags assigned to the items by the viewer. Additionally, this module implements (i) a novel item stereotype to represent newly arrived items, (ii) a standard user stereotype for new users, (iii) a novel passive user tag cloud stereotype for socially passive users, and (iv) a new content-based filter named the collinearity and proximity similarity (CPS). At the end of the paper, we present off-line results and a case study describing how the recommendation service works. The proposed system provides, to our knowledge, an excellent holistic solution to the problem of recommending multimedia contents.

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This paper analyzes the signals captured during impacts and vibrations of a mechanical manipulator. The Fourier Transform of eighteen different signals are calculated and approximated by trendlines based on a power law formula. A sensor classification scheme based on the frequency spectrum behavior is presented.

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Signal Processing: Algorithms, Architectures, Arrangements, and Applications (SPA), 2013

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Sertraline is widely prescribed worldwide and frequently detected in aquatic systems. There is, however, a remarkable gap of information on its potential impact on estuarine and coastal invertebrates. This study investigated sertraline accumulation and effects in Carcinus maenas. Crabs from a moderately contaminated (Lima) and a low-impacted (Minho) estuary were exposed to environmental and high levels of sertraline (0.05, 5, 500 μg L−1). A battery of biomarkers related to sertraline mode of action was employed to assess neurotransmission, energy metabolism, biotransformation and oxidative stress pathways. After a seven-day exposure, sertraline accumulation in crabs’ soft tissues was found in Lima (5 μg L−1: 15.3 ng L−1 ww; 500 μg L−1: 1010 ng L−1 ww) and Minho (500 μg L−1: 605 ng L−1 ww) animals. Lima crabs were also more sensitive to sertraline than those from Minho, exhibiting decreased acetylcholinesterase activity, indicative of ventilatory and locomotory dysfunction, inhibition of anti-oxidant enzymes and increased oxidative damage at ≥0.05 μg L−1. The Integrated Biomarker Response (IBR) index indicated their low health status. In addition, Minho crabs showed non-monotonic responses of acetylcholinesterase suggestive of hormesis. The results pointed an influence of the exposure history on differential sensitivity to sertraline and the need to perform evaluations with site-specific ecological receptors to increase relevance of risk estimations when extrapolating from laboratory to field conditions.

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Near real time media content personalisation is nowadays a major challenge involving media content sources, distributors and viewers. This paper describes an approach to seamless recommendation, negotiation and transaction of personalised media content. It adopts an integrated view of the problem by proposing, on the business-to-business (B2B) side, a brokerage platform to negotiate the media items on behalf of the media content distributors and sources, providing viewers, on the business-to-consumer (B2C) side, with a personalised electronic programme guide (EPG) containing the set of recommended items after negotiation. In this setup, when a viewer connects, the distributor looks up and invites sources to negotiate the contents of the viewer personal EPG. The proposed multi-agent brokerage platform is structured in four layers, modelling the registration, service agreement, partner lookup, invitation as well as item recommendation, negotiation and transaction stages of the B2B processes. The recommendation service is a rule-based switch hybrid filter, including six collaborative and two content-based filters. The rule-based system selects, at runtime, the filter(s) to apply as well as the final set of recommendations to present. The filter selection is based on the data available, ranging from the history of items watched to the ratings and/or tags assigned to the items by the viewer. Additionally, this module implements (i) a novel item stereotype to represent newly arrived items, (ii) a standard user stereotype for new users, (iii) a novel passive user tag cloud stereotype for socially passive users, and (iv) a new content-based filter named the collinearity and proximity similarity (CPS). At the end of the paper, we present off-line results and a case study describing how the recommendation service works. The proposed system provides, to our knowledge, an excellent holistic solution to the problem of recommending multimedia contents.

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In the last few years the number of systems and devices that use voice based interaction has grown significantly. For a continued use of these systems the interface must be reliable and pleasant in order to provide an optimal user experience. However there are currently very few studies that try to evaluate how good is a voice when the application is a speech based interface. In this paper we present a new automatic voice pleasantness classification system based on prosodic and acoustic patterns of voice preference. Our study is based on a multi-language database composed by female voices. In the objective performance evaluation the system achieved a 7.3% error rate.

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This article studies the intercultural trajectory of a Portuguese female aristocrat of the eighteenth to nineteenth centuries. Her trajectory of intercultural transition from a Portuguese provincial lady into an independent owner of a sugar mill in tropical Bahia is documented through family letters, which provide a polyphonic representation of a movement of personal, family, and social transculturation over almost two decades. Maria Bárbara began her journey between cultures as a simple spectator-reader, progressively becoming a commentator-actor-protagonist-author in society, in politics, and in history. These letters function as a translation that is sometimes consecutive, other times simultaneous, of the events lived and witnessed. This concept of intercultural translation is based on the theories of Boaventura de Sousa Santos (2006, 2008), who argues that cultural differences imply that any comparison has to be made using procedures of proportion and correspondence which, taken as a whole, constitute the work of translation itself. These procedures construct approximations of the known to the unknown, of the strange to the familiar, of the ‘other’ to the ‘self’, categories which are always unstable. Likewise, this essay explores the unstable contexts of its object of study, with the purpose of understanding different rationalities and worldviews.