67 research outputs found

    Traveled Distance Estimation Algorithm for Indoor Localization

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    This paper presents an ankle mounted Inertial Navigation System (INS) used to estimate the distance traveled by a pedestrian. This distance is estimated by the number of steps given by the user. The proposed method is based on force sensors to enhance the results obtained from an INS. Experimental results have shown that, depending on the step frequency, the traveled distance error varies between 2.7% and 5.6%

    Mathgebra - Organização e Tratamento de Dados no 2º Ciclo

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    Este é um livro interativo! É aconselhado a utilização do software “Adobe Acrobat Reader”. Optimizado para resoluções acima de 1024x720px.E-book que permite a exploração de conteúdos previstos no programa e nas metas curriculares de Matemática para o 2.ª Ciclo do Ensino Básico. Nele ficarão acessíveis um conjunto de atividades que se poderão realizar através dos mais variados recursos interativos construídos no Geogebra. A importância deste e-book adquire maior relevância didática quando prevê estratégias de aprendizagem baseadas na tentativa e erro que favorecem a descoberta pessoal, desenvolvendo-se, por isso mesmo, a autonomia e o espírito crítico

    Solução de navegação inercial para o sistema plasys

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    Neste trabalho faz-se uma pesquisa e análise dos conceitos associados à navegação inercial para estimar a distância percorrida por uma pessoa. Foi desenvolvida uma plataforma de hardware para implementar os algoritmos de navegação inercial e estudar a marcha humana. Os testes efetuados permitiram adaptar os algoritmos de navegação inercial para humanos e testar várias técnicas para reduzir o erro na estimativa da distância percorrida. O sistema desenvolvido é um sistema modular que permite estudar o efeito da inserção de novos sensores. Desta forma foram adaptados os algoritmos de navegação para permitir a utilização da informação dos sensores de força colocados na planta do pé do utilizador. A partir desta arquitetura foram efetuadas duas abordagens para o cálculo da distância percorrida por uma pessoa. A primeira abordagem estima a distância percorrida considerando o número de passos. A segunda abordagem faz uma estimação da distância percorrida com base nos algoritmos de navegação inercial. Foram realizados um conjunto de testes para comparar os erros na estimativa da distância percorrida pelas abordagens efetuadas. A primeira abordagem obteve um erro médio de 4,103% em várias cadências de passo. Este erro foi obtido após sintonia para o utilizador em questão. A segunda abordagem obteve um erro de 9,423%. De forma a reduzir o erro recorreu-se ao filtro de Kalman o que levou a uma redução do erro para 9,192%. Por fim, recorreu-se aos sensores de força que permitiram uma redução para 8,172%. A segunda abordagem apesar de ter um erro maior não depende do utilizador pois não necessita de sintonia dos parâmetros para estimar a distância para cada pessoa. Os testes efetuados permitiram, através dos sensores de força, testar a importância da força sentida pela planta do pé para aferir a fase do ciclo de marcha. Esta capacidade permite reduzir os erros na estimativa da distância percorrida e obter uma maior robustez neste tipo de sistemas.In this work is presented the research and the analysis of the inertial navigation concepts to estimate the distance travelled by a person. It was developed a hardware platform to implement the inertial navigation algorithms and study the human gait. The tests with the platform allowed adapting the inertial navigation algorithms to humans and to test several techniques to reduce the error in the estimation of the traveled distance. The developed system is a modular system which allows studying the effect of inclusion of new sensors. Thus the navigation algorithms have been adapted to use the information from force sensors placed in the foot of the user. Based on this architecture, it was used two approaches to calculate the distance traveled by a person. The first approach estimate the travelled distance based on the step cadence. The second approach estimate the travelled distance based on the inertial navigation algorithms. It was performed a series of tests to compare the errors in the estimation of the travelled distance for each approaches. The first approach achieved an average error of 4.103% in several step cadences. This error was obtained after tuning the algorithm to the user. The second approach achieved an average error of 9.423%. To reduce the error it was used the Kalman filter which led to a reduction of the error to 9.192%. Finally, it was addressed the force sensors which led to a reduction of the error to 8.172%. The second approach, despite having a higher error, is independent of the user and it does not require the tuning of the parameters to estimate distance for each person. The tests results show the importance of the force sensors placed on the plant of the foot to assess the phase of the gait cycle. This ability allows to reduce the errors in estimating the distance and increases robustness in such systems

    SAT-Based Algorithms for Regular Graph Pattern Matching

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    Graph matching is a fundamental problem in pattern recognition, with many applications such as software analysis and computational biology. One well-known type of graph matching problem is graph isomorphism, which consists of deciding if two graphs are identical. Despite its usefulness, the properties that one may check using graph isomorphism are rather limited, since it only allows strict equality checks between two graphs. For example, it does not allow one to check complex structural properties such as if the target graph is an arbitrary length sequence followed by an arbitrary size loop. We propose a generalization of graph isomorphism that allows one to check such properties through a declarative specification. This specification is given in the form of a Regular Graph Pattern (ReGaP), a special type of graph, inspired by regular expressions, that may contain wildcard nodes that represent arbitrary structures such as variable-sized sequences or subgraphs. We propose a SAT-based algorithm for checking if a target graph matches a given ReGaP. We also propose a preprocessing technique for improving the performance of the algorithm and evaluate it through an extensive experimental evaluation on benchmarks from the CodeSearchNet dataset.Comment: Shorter version accepted for publication at AAAI 202

    As energias renováveis aliadas à construção sustentável

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    Mestrado em Engenharia CivilO objectivo fundamental desta tese visa aprofundar o conhecimento no domínio das tecnologias energéticas, gestão e desenvolvimento sustentável, com vista à racionalização e utilização eficiente de energia em edifícios. A recente regulamentação no domínio da térmica de edifícios veio conferir grande importância à integração e utilização de sistemas baseados em energias renováveis, o que poderá melhorar a qualidade de vida nos edifícios através de uma utilização mais racional de energia. Neste contexto, foi feita, numa primeira fase, uma análise ao comportamento térmico de um edifício para três zonas em Portugal com características climáticas distintas para, a partir dai, tentar perceber as principais diferenças relativamente às exigências do regulamento em vigor com a disparidade dos consumos energéticos nessas regiões. Por se ter constatado essas diferenças, procurou-se reduzir significativamente o gasto de energia para a climatização do edifício, procedendo-se a alterações ao nível das características do edifício, designadamente ao nível da envolvente opaca do edifício e vãos envidraçados. Outro tema abordado refere-se à problemática da sustentabilidade no ramo da energia, consumo e fontes renováveis: uma primeira parte, descreveu-se as fontes de energia que podem ser aplicadas ao sector dos edifícios. Na segunda parte, dimensionaram-se as várias fontes renováveis de energia para se tornar o edifício produtor da totalidade da energia necessária ao seu abastecimento. Por fim, foi feito um estudo da viabilidade económica sobre as diferentes hipóteses consideradas para se verificar se as alterações propostas são ou não vantajosas As conclusões retiradas, são que o mesmo edifício comporta-se de modo distinto consoante a região climática em que está inserido. Assim, em Bragança o edifício necessita de uma elevada quantidade de energia para suprir as necessidades climáticas durante o Inverno. No Verão, como o clima é muito mais quente o edifício situado em Beja apresente necessidades de arrefecimento mais elevadas. As alterações propostas ao nível do comportamento térmico são claramente vantajosas, tanto do ponto de vista da qualidade de vida como economicamente, já que ao fim de relativamente pouco tempo o investimento é completamente amortizado. Contudo, no que se refere à utilização das fontes renováveis de energia, o investimento só fica amortizado quase no fim da vida útil considerada para o equipamento, pelo que economicamente não é, para já, uma aposta muito rentável. Porém, em termos ambientais, é sem dúvida a melhor opção. ABSTRACT: The fundamental aim of this paper is to expand the knowledge of the energetic technologies, management and sustainable development in order to rationalize and make an efficient use of energy in buildings. Recent regulation in the thermal performance of buildings gave great importance to the integration and use of renewable energy systems that, could improve the quality of life in the buildings through a more rational use of energy. In this context, in a first phase, a thermal behaviour analysis of a building was made, in three Portuguese regions with different climatic characteristics to allow understanding the main differences related to the regulation in force demands with the energetic consumption disparity in these regions. When these differences were detected, considerable reductions on the energy spent to climate the building, were made possible by altering the building characteristics specially the opaque enclosure of the building and the glass spans. Another important theme, refers to the problematic of sustainability in the fields of energy, consumption and renewable sources: in a first phase, energy sources that can be applied in the building sector were described On a second phase, the different renewable energy sources were studied in order to make the building produce all the energy needed to supply itself. Finally, an economic viability study was made, regarding the different hypothesis considered to check if the proposed changes are profitable or not. The conclusion is that the same building has different behaviours according to the climatic region surrounding it. So, the building in Bragança needs a higher energy output to supply its climatic needs during winter. On summer, because the weather is hotter, the building located in Beja shows higher cooling needs. The proposed changes on thermal behaviour are clearly profitable, not only for the quality of life but also economically since after short time the investment is completely amortized. However, in terms of using renewable energy sources, the investment is just amortized almost by the end of the useful life of said equipment. Economically speaking it is not, by now, a rentable solution. However, in environmental terms this is, for sure, the best option

    Lung Cancer and the COVID-19 pandemic: Recommendations from the Brazilian Thoracic Oncology Group

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    New cases of the novel coronavirus disease 2019 (COVID-19), also known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continue to rise worldwide following the declaration of a pandemic by the World Health Organization (WHO). The current pandemic has completely altered the workflow of health services worldwide. However, even during this critical period, patients with other diseases, like cancer, need to be properly treated. A few reports have shown that mortality due to SARS-CoV-2 is higher in elderly patients and those with other active comorbidities, including cancer. Patients with lung cancer are at risk of pulmonary complications from COVID-19, and as such, the risk/benefit ratio of local and systemic anticancer treatment has to be considered. For each patient, several factors, including age, comorbidities, and immunosuppression, as well as the number of hospital visits for treatment, can influence this risk. The number of cases is rising exponentially in Brazil, and it is important to consider the local characteristics when approaching the pandemic. In this regard, the Brazilian Thoracic Oncology Group has developed recommendations to guide decisions in lung cancer treatment during the SARS-CoV-2 pandemic. Due to the scarcity of relevant data, discussions based on disease stage, evaluation of surgical treatment, radiotherapy techniques, systemic therapy, follow-up, and supportive care were carried out, and specific suggestions issued. All recommendations seek to reduce contagion risk by decreasing the number of medical visits and hospitalization, and in the case of immunosuppression, by adapting treatment schemes when possible. This statement should be adjusted according to the reality of each service, and can be revised as new data become available

    The role of ETG modes in JET-ILW pedestals with varying levels of power and fuelling

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    We present the results of GENE gyrokinetic calculations based on a series of JET-ITER-like-wall (ILW) type I ELMy H-mode discharges operating with similar experimental inputs but at different levels of power and gas fuelling. We show that turbulence due to electron-temperature-gradient (ETGs) modes produces a significant amount of heat flux in four JET-ILW discharges, and, when combined with neoclassical simulations, is able to reproduce the experimental heat flux for the two low gas pulses. The simulations plausibly reproduce the high-gas heat fluxes as well, although power balance analysis is complicated by short ELM cycles. By independently varying the normalised temperature gradients (omega(T)(e)) and normalised density gradients (omega(ne )) around their experimental values, we demonstrate that it is the ratio of these two quantities eta(e) = omega(Te)/omega(ne) that determines the location of the peak in the ETG growth rate and heat flux spectra. The heat flux increases rapidly as eta(e) increases above the experimental point, suggesting that ETGs limit the temperature gradient in these pulses. When quantities are normalised using the minor radius, only increases in omega(Te) produce appreciable increases in the ETG growth rates, as well as the largest increases in turbulent heat flux which follow scalings similar to that of critical balance theory. However, when the heat flux is normalised to the electron gyro-Bohm heat flux using the temperature gradient scale length L-Te, it follows a linear trend in correspondence with previous work by different authors

    Spectroscopic camera analysis of the roles of molecularly assisted reaction chains during detachment in JET L-mode plasmas

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    The roles of the molecularly assisted ionization (MAI), recombination (MAR) and dissociation (MAD) reaction chains with respect to the purely atomic ionization and recombination processes were studied experimentally during detachment in low-confinement mode (L-mode) plasmas in JET with the help of experimentally inferred divertor plasma and neutral conditions, extracted previously from filtered camera observations of deuterium Balmer emission, and the reaction coefficients provided by the ADAS, AMJUEL and H2VIBR atomic and molecular databases. The direct contribution of MAI and MAR in the outer divertor particle balance was found to be inferior to the electron-atom ionization (EAI) and electron-ion recombination (EIR). Near the outer strike point, a strong atom source due to the D+2-driven MAD was, however, observed to correlate with the onset of detachment at outer strike point temperatures of Te,osp = 0.9-2.0 eV via increased plasma-neutral interactions before the increasing dominance of EIR at Te,osp < 0.9 eV, followed by increasing degree of detachment. The analysis was supported by predictions from EDGE2D-EIRENE simulations which were in qualitative agreement with the experimental observations
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