1000 resultados para Algoritmos quase-analíticos
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Doutoramento em Matemática Aplicada à Economia e à Gestão.
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Dissertação de mestrado, Ciências Farmacêuticas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014
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Dissertação de mest. em Engenharia de Sistemas e Computação - Área de Sistemas de Controlo, Faculdade de Ciências e Tecnologia, Univ.do Algarve, 2001
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Os betões atuais são materiais com custos extremamente competitivos devido ao baixo custo do cimento Portland. Contudo, os elevados níveis de emissões de C02 gerados na sua produção provocam o aumento do custo final do produto, tanto económico como ambiental. Devido a esta situação algumas adições têm sido estudadas como alternativas para substituir parcialmente os conteúdos de cimento no fabrico de betão. Uma vez que existem grandes quantidades de pó de mármore inutilizadas na região de Évora decidiu-se avaliar o seu comportamento. O pó de mármore foi adicionado em certas percentagens de forma a reduzir os conteúdos de cimento, permitindo avaliar se este iria manter e/ou melhorar as características de resistência à compressão e trabalhabilidade do betão. Além de avaliado o comportamento desta adição, o mesmo foi também comparado com a adição de filer calcário nas mesmas percentagens. Os resultados obtidos demonstraram a exequibilidade da utilização de ambas as adições. ABSTRACT: Concretes currently used in construction are materials with very competitive costs due to the low cost of Portland cement. However, high levels of C02 emissions generated in its production cause an increase of the final cost of the product, both economically and environmentally. Due to this situation, some additions have been studied as alternatives to replace partially cement contents in concrete production. Since there are large quantities of marble dust in the region of Évora, it was decided to evaluate his behavior. The marble dust was added in known percentages so the cement contents could be reduced, allowing evaluating if it will maintain and/or improve the characteristics of the compressive strength and workability of the concrete. ln addition to evaluating the behavior of marble dust, this addition was also compared with the addition of limestone filler in the same percentages. The results demonstrated the feasibility of using both additions.
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This master dissertation presents the study and implementation of inteligent algorithms to monitor the measurement of sensors involved in natural gas custody transfer processes. To create these algoritmhs Artificial Neural Networks are investigated because they have some particular properties, such as: learning, adaptation, prediction. A neural predictor is developed to reproduce the sensor output dynamic behavior, in such a way that its output is compared to the real sensor output. A recurrent neural network is used for this purpose, because of its ability to deal with dynamic information. The real sensor output and the estimated predictor output work as the basis for the creation of possible sensor fault detection and diagnosis strategies. Two competitive neural network architectures are investigated and their capabilities are used to classify different kinds of faults. The prediction algorithm and the fault detection classification strategies, as well as the obtained results, are presented
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Los protocolos de medición antropométrica se caracterizan por la profusión de medidas discretas o localizadas, en un intento para caracterizar completamente la forma corporal del sujeto -- Dichos protocolos se utilizan intensivamente en campos como medicina deportiva, forense y/o reconstructiva, diseño de prótesis, ergonomía, en la confección de prendas, accesorios, etc -- Con el avance de algoritmos de recuperación de formas a partir de muestreos (digitalizaciones) la caracterización antropométrica se ha alterado significativamente -- El articulo presente muestra el proceso de caracterización digital de forma corpórea, incluyendo los protocolos de medición sobre el sujeto, el ambiente computacional - DigitLAB- (desarrollado en el CII-CAD-CAM-CG de la Universidad EAFIT) para recuperación de superficies, hasta los modelos geométricos finales -- Se presentan comparaciones de los resultados obtenidos con DigitLAB y con paquetes comerciales de recuperación de forma 3D -- Los resultados de DigitLAB resultan superiores, debido principalmente al hecho de que este toma ventaja de los patrones de las digitalizaciones (planares de contacto, por rejilla de pixels - range images -, etc.) y provee módulos de tratamiento geométrico - estadístico de los datos para poder aplicar efectivamente los algoritmos de recuperación de forma -- Se presenta un caso de estudio dirigido a la industria de la confección, y otros efectuados sobre conjuntos de prueba comunes en el ámbito científico para la homologación de algoritmos
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Apresenta-se parte de um trabalho de monitorização da qualidade da água (2014 e 2015) e de compilação de informação sobre os solos do regadio do Roxo (RR), visando uma avaliação da salinização e sodização do solo. Admite-se que as limitações e lacunas de informação encontradas neste caso são representativas de outros regadios do sul do país. O RR ocupa uma área de ~8.250 ha a norte de Aljustrel, ao longo da ribeira do Roxo, em formações sedimentares cenozóicas da bacia de Alvalade. Decresce de SE para NW de 120 m até 47 m maioritariamente em declives suaves. Segundo a Carta dos Solos de Portugal apresenta Luvisols (~40%), Fluvisols e Regosols (~20%), Gleysols e Planosols (~20%) e Vertisols (~10%), no entanto, identificaram-se apenas 5 perfis de solo com caracterização analítica do final do séc. XX. A água de rega do RR em 2014 e 2015 revelou ligeira a moderada salinidade e ausência de restrições para a infiltração enquanto a água drenada chegou quase ao limite de salinidade grave mas manteve-se sem restrições para a infiltração. Os dados disponíveis sobre os solos apresentam baixa salinidade, mas 4 em 5 perfis são sódicos segundo a WRB, contudo, o que sobressai desta análise é a grande lacuna de dados analíticos de solos no RR.
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Objetivos: refletir acerca de algumas praticas de sala de aula da geografia escolar no estado do Rio Grande do Sul (Brasil), bem como propor que a docência da geografia incorpore as categorias espaciais - sobretudo espaço, territorio, lugar, região, natureza - como um exercicio ontológico que pense permanentente espaço, tempo e cultura como constituidoras da condição humana. Método: utilizando relatos de estagiários da licenciatura em Geografia questionamos a pratica dos docentes da disciplina no Ensino Fundamental e Médio. Valendo-nos da poesia (Fernando Pessoa), da literatura (Guimarães Rosa) e de autores da geografia (varios), bem como do sociologo Edgar Morin queremos propor temáticas para a renovação das praticas docentes. Contribuições: refletir sobre a pratica docente da geografia escolar, propor alternativas de temas e de didáticas que auxiliem os docentes na busca de uma maior atratividade e reflexividade da disciplina
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2008
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Algoritmos diagnósticos de tuberculose para pessoas vivendo com HIV/AIDS com o teste rápido molecular para tuberculose (TRM-TB).
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Remotely sensed imagery has been widely used for land use/cover classification thanks to the periodic data acquisition and the widespread use of digital image processing systems offering a wide range of classification algorithms. The aim of this work was to evaluate some of the most commonly used supervised and unsupervised classification algorithms under different landscape patterns found in Rondônia, including (1) areas of mid-size farms, (2) fish-bone settlements and (3) a gradient of forest and Cerrado (Brazilian savannah). Comparison with a reference map based on the kappa statistics resulted in good to superior indicators (best results - K-means: k=0.68; k=0.77; k=0.64 and MaxVer: k=0.71; k=0.89; k=0.70 respectively for three areas mentioned). Results show that choosing a specific algorithm requires to take into account both its capacity to discriminate among various spectral signatures under different landscape patterns as well as a cost/benefit analysis considering the different steps performed by the operator performing a land cover/use map. it is suggested that a more systematic assessment of several options of implementation of a specific project is needed prior to beginning a land use/cover mapping job.
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Cardboard packing for horticultural products has as main function to protect them. The design of a cardboard packing request the knowledge of the bending stiffens which is depending on the modulus of elasticity. The objective of this work was to calculate the cardboard modulus of elasticity from data obtained in laboratory using physical characterization test, with different methods, and comparing the results with the values obtained experimentally. Ten samples of each cardboard selected for this study were tested in the paper fabrication direction and in its transverse direction. The papers liner and medium resistance to the traction, used to calculate the bending stiffness, was determined in a universal machine test. To obtaining of the bending stiffens the four points test was accomplished. Expressive variations among the methods from which the modulus of elasticity is obtained were observed and that influence the bending stiffness of the structure. The stiffness values obtained experimentally were always greater than the values obtained from analytical method. This difference can be attributed to two factors, the production processes that assurance a larger rigidity than the components separately and the addition of the adhesive layer that is not taken in consideration in the analytic calculations.
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The objective of this work was to compare the soybean crop mapping in the western of Parana State by MODIS/Terra and TM/Landsat 5 images. Firstly, it was generated a soybean crop mask using six TM images covering the crop season, which was used as a reference. The images were submitted to Parallelepiped and Maximum Likelihood digital classification algorithms, followed by visual inspection. Four MODIS images, covering the vegetative peak, were classified using the Parallelepiped method. The quality assessment of MODIS and TM classification was carried out through an Error Matrix, considering 100 sample points between soybean or not soybean, randomly allocated in each of the eight municipalities within the study area. The results showed that both the Overall Classification (OC) and the Kappa Index (KI) have produced values ranging from 0.55 to 0.80, considered good to very good performances, either in TM or MODIS images. When OC and KI, from both sensors were compared, it wasn't found no statistical difference between them. The soybean mapping, using MODIS, has produced 70% of reliance in terms of users. The main conclusion is that the mapping of soybean by MODIS is feasible, with the advantage to have better temporal resolution than Landsat, and to be available on the internet, free of charge.
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One of the effects of the globalized world is a strong tendency to eliminate differences, promoting a planetary culture. Education systems are particularly affected, undergoing strong pressure from international studies and evaluations, inevitably comparative, and sadly competitive. As a result, one observes the gradual elimination of cultural components in the definition of education systems. The constitution of new social imaginaries becomes clear; imaginaries empty of historical, geographical and temporal referents, characterized by a strong presence of the culture of the image. The criteria of classification establish an inappropriate reference that has as its consequence the definition of practices and even of education systems. On the other hand, resistance mechanisms, often unconscious, are activated seeking to safeguard and recover the identifying features of a culture, such as its traditions, cuisine, languages, artistic manifestations in general, and, in doing so, to contribute to cultural diversity, an essential factor to encourage creativity. In this article, the sociocultural basis of mathematics and of its teaching are examined, and also the consequences of globalization and its effects on multicultural education. The concept of culture is discussed, as well as issues related to culture dynamics, resulting in the proposition of a theory of transdisciplinar and transcultural knowledge. Upon such basis the Ethnomathematics Program is presented. A critique is also made of the curriculum presently used, which is in its conception and detailing, obsolete, uninteresting and of little use. A different concept of curriculum is proposed, based on the communicative (literacy), analytical (matheracy), and material (technoracy) instruments.