1,706 research outputs found

    Peer-to-peer and community-based markets: A comprehensive review

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    The advent of more proactive consumers, the so-called "prosumers", with production and storage capabilities, is empowering the consumers and bringing new opportunities and challenges to the operation of power systems in a market environment. Recently, a novel proposal for the design and operation of electricity markets has emerged: these so-called peer-to-peer (P2P) electricity markets conceptually allow the prosumers to directly share their electrical energy and investment. Such P2P markets rely on a consumer-centric and bottom-up perspective by giving the opportunity to consumers to freely choose the way they are to source their electric energy. A community can also be formed by prosumers who want to collaborate, or in terms of operational energy management. This paper contributes with an overview of these new P2P markets that starts with the motivation, challenges, market designs moving to the potential future developments in this field, providing recommendations while considering a test-case

    Portable Snow-Bike

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    The world of extreme sports and more specifically the world of snow sports is changing by the minute. At the forefront of these new changes is the snow bike. The bike allows you to ride the mountain like you were riding a mountain-bike on skies, but it comes with challenges. The biggest of them being portability. The bike is restricted to certain types of lifts within the mountain and that restricts the user of its potential. This report will show that it is possible to “fold” both the frame and the handlebars to make the bike portable and therefore opening the user to new opportunities. This report shows with the use of the proper material, in this case steel, welded and fabricated correctly can withstand the forces and impacts the bike might encounter. As such, this essay will provide conclusive and positive results to both its physical and theoretical tests. The prototype will be ridden at Stevens pass resort to test its actual resistance to a drop from about 3.5 meters into snow. The frame and the handlebars will also be tested for any deformation, and stresses such as compression, tension and shear. The bike is expected to respond mostly as the original, with some minor extra shaking due to the pins responsible for the attachments

    Englishing The Lusiad. Richard Fanshawe?s translation of Os Lusíadas and its relation with the contemporary English political context

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    Os Lusíadas, by the Portuguese poet Luís de Camões, was first translated into English at a time of profound social and political uncertainty. Published in 1655 during the Interregnum, and translated by Sir Richard Fanshawe (1608-1666), a loyal royalist and courtier of Charles I, The Lusiad became the first translation of the epic to be made outside of the Iberian Peninsula, and the first major literary exchange between Portugal and England. In addition to its foundational role in bringing Portuguese literature into England, the timing of The Lusiad's publication and the political allegiances of its translator raise the possibility that, in its first iteration in English, Camões's epic was re-shaped by the political context in which it was produced. This thesis re-visits the first English translation of Os Lusíadas in order to ascertain to what extent and in what way the Portuguese epic was shaped by the British political environment of the 1650s. It closely examines the life and career path of Richard Fanshawe that led to the choice of Camões's epic as an object of translation and how that choice changed his life in the aftermath of the Restoration, effectively making him the ideal candidate for the post of Ambassador to Portugal. It performs a close reading of the translation and its accompanying paratexts in relation to the context of the publication, identifying and highlighting the elements that Fanshawe consciously refashioned to address the specific problems Britain faced in the mid-seventeenth century. Englishing The Lusiad argues that Richard Fanshawe performed a specific kind of appropriation of its object by subtly redirecting themes and scenes in the original Portuguese text towards the events of the English Civil Wars and the Interregnum

    Efeito do encurtamento muscular dos flexores da anca na actividade muscular dos extensores da anca, durante uma tarefa de agachamento, em jovens jogadores de futebol

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    Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciado em FisioterapiaObjetivo: O objectivo deste estudo foi comparar a força muscular dos músculos flexores e extensores da anca, assim como a resposta electromiográfica dos extensores da anca, durante uma tarefa dinâmica de agachamento, em atletas juvenis de futebol masculino, com e sem encurtamento dos músculos flexores da anca. Metodologia: 18 jogadores de futebol, do sexo masculino, pertencentes ao Padroense Futebol Clube, com média de idades de 16,0 ± 1,372 anos, peso 62,877 ± 8,945 kg e altura 1,726 ± 0,085m, participaram no presente estudo. Com recurso ao Teste de Thomas, os atletas foram seleccionados para um grupo de teste (teste de Thomas positivo – presença de encurtamento) ou um grupo de controlo (teste de Thomas negativo – ausência de encurtamento). Foi avaliada a força muscular isométrica dos músculos isquiotibiais, glúteo máximo e iliopsoas com recurso a célula de carga e foi analisada a actividade electromiográfica dos músculos isquiotibiais e glúteo máximo durante o agachamento. Resultados: Não foram observadas diferenças significativas que comprovassem a existência de diferenças para a força e a activação muscular entre atletas com e sem encurtamento muscular dos flexores da anca. Conclusão: Para a amostra estudada, não foram encontradas diferenças em termos de força e activação eletromiográfica, para os músculos em estudo, entre atletas com e sem encurtamento dos flexores da anca.Objective: The aim of this study was to compare the muscle strength of hip flexor and extensor muscles, as well as the electromyographic response of the hip extensors during a dynamic squat task in youth male football athletes, with and without shortening of hip flexors muscles. Methodology: 18 soccer players, male, of the club Padroense Futebol Clube with a mean age of 16,0 ± 1,372, weight 62,877 ± 8,945 kg and height 1,726 ± 0,085 m participated on this study. Using the Modified Thomas Test, the athletes were selected to a test group (positive Thomas Test – presence of shortening) or a control group (negative Thomas Test – absence of shortening). Isometric muscle strength was evaluated on the hamstrings, gluteus maximus and iliopsoas muscles by using a load cell and it was analyzed the electromiographic activity of the hamstrings and gluteus maximus during squat. Results: No significant differences were found which would conclusively prove the existence of differences to the muscle strength and muscle activation between athletes with and without muscle shortening of the hip flexors. Conclusion: For the study sample, no differences were found in terms of strength and eletromyographic activation of the muscles in study, between athletes with and without shortening of the hip flexors.N/

    Methods for conceptual and preliminary seismic design of buildings with steel structure

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    Throughout the last two decades, seismic design standards evolved to ever more comprehensive and detailed prescriptions, stressing out the need for design methods that deal with earthquake effects not as actions, but as a design philosophy. The Eurocode 8 adoption as national law throughout the European Union countries and informally in many parts of Africa, Asia and Latin America is the pretext for the current study. It aims to provide some guidance to the seismic design of steel structures as well as to the Eurocode 8 implementation by the designers. Some lines on the preliminary design of structural systems were written based on several real cases of structures designed taking into account the seismic action. Such a content is, usually, relevant in any design guide, given its value in enhancing the design technical and economical content. However, it is now of utter significance at the current context as an essential tool to facilitate the safety checking of several code requirements. Some of the Eurocode 8 prescriptions are then decoded, explained and justified based on the supportive bibliography. The information is subsequently ordered as a design guide, where some procedures are proposed to cope with the code interrelated prescriptions and one structural solution is proposed in order to overcome a design challenge while complying with the code. One last but not less relevant addressed issue is the fact that some Eurocode 8 prescriptions may be reviewed, in the eyes of a designer, given its practical outcome. Such issues are identified, explained and some slight code adjustments are suggested

    Exploring Different Methods for Solving Analogies with Portuguese Word Embeddings

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    A common way of assessing static word embeddings is to use them for solving analogies of the kind "what is to king as man is to woman?". For this purpose, the vector offset method (king - man + woman = queen), also known as 3CosAdd, has been effectively used for solving analogies and assessing different models of word embeddings in different languages. However, some researchers pointed out that this method is not the most effective for this purpose. Following this, we tested alternative analogy solving methods (3CosMul, 3CosAvg, LRCos) in Portuguese word embeddings and confirmed the previous statement. Specifically, those methods are used to answer the Portuguese version of the Google Analogy Test, dubbed LX-4WAnalogies, which covers syntactic and semantic analogies of different kinds. We discuss the accuracy of different methods applied to different models of embeddings and take some conclusions. Indeed, all methods outperform 3CosAdd, and the best performance is consistently achieved with LRCos, in GloVe

    Bicycles Mobility Prediction

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    The growth in mobile wireless communication requires sharp solutions in handling mobility problems that encompass poor handover management, interference in access points, excessive load in macrocells, and other relevant mobility issues. With the deployment of small cell networks in 5G mobile systems the problems mentioned intensify thus, mobility prediction schemes arise to surpass and mitigate these issues. Predicting mobility is not a trivial task due to the vastness of different variables that characterize a mobility route translating into unpredictability and randomness. Therefore, the task of this work is to overcome these challenges by building a solid mobility prediction architecture that can analyze big data and find patterns in the mobility aspect to ultimately perform reliable predictions. The models introduced in this dissertation are two deep learning schemes based on an Artificial Neural Network (ANN) architecture and a LSTM Long-Short Term Memory (LSTM) architecture. The prediction was made in two levels: Short-term prediction and Long-term prediction. We verified that in the short-term domain both models performed equivalently with successful results. However, in long-term prediction, the LSTM model surpassed the ANN model. Consequently, the LSTM approach constitutes the stronger model in all prediction aspects. Implementing this model in cellular networks is an important asset in optimizing processes such as routing and caching as the cellular networks can allocate the necessary resources to provide a better user experience. With this optimization impact and with the emergence of the Internet of Things (IoT), the prediction model can support and improve the development of smart applications related to our daily mobility routine.O crescimento da comunicação móvel sem fios exige soluções precisas para lidar com problemas de mobilidade que englobam uma gestão pobre de handover, interferência em pontos de acesso, carga excessiva em macrocélulas e outros problemas relevantes ao aspeto da mobilidade. Com a implantação de redes de pequenas células no sistema móvel 5G, os problemas mencionados intensificam-se. Desta forma, são necessários esquemas de previsão de mobilidade para superar e mitigar esses problemas. Prever a mobilidade não é uma tarefa trivial devido à imensidão de diferentes variáveis que caracterizam uma rota de mobilidade, traduzindo-se em grandes dimensões de imprevisibilidade e aleatoriedade. Portanto, a tarefa deste trabalho é superar esses desafios construindo uma arquitetura sólida de estimação de mobilidade, que possa analisar um grande fluxo de dados e encontrar padrões para, em última análise, realizar previsões credíveis e assertivas. Os modelos apresentados nesta dissertação são dois esquemas de deep learning baseados em uma arquitetura de RNA (Rede Neuronal) e uma arquitetura LSTM (Long-Short Term Memory). A previsão foi feita em dois níveis: previsão de curto prazo e previsão de longo prazo. Verificámos que no curto prazo ambos os modelos tiveram um desempenho equivalente com resultados bem sucedidos. No entanto, na previsão de longo prazo, o modelo LSTM superou o modelo ANN. Consequentemente, a abordagem LSTM constitui o modelo mais forte em todos os aspectos de previsão. A implementação deste modelo, em redes celulares, é uma medida importante na otimização de processos como, routing ou caching, proporcionando uma melhor experiência wireless ao utilizador. Com este impacto de otimização e com o surgimento da Internet of Things (IoT), o modelo de previsão pode apoiar e melhorar o desenvolvimento de aplicações inteligentes relacionadas com a nossa rotina diária de mobilidade
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