20 resultados para inverted repeat
em Repositório Científico do Instituto Politécnico de Lisboa - Portugal
Resumo:
Partindo da explicação daquilo que neste ensaio se entende por “metacinema” e a sua relevância como discurso autoral sobre a sétima arte, aborda-se o fenómeno do visionamento múltiplo de uma mesma obra (aspeto conhecido em inglês como “repeat viewing”). Este fenómeno permite um contato privilegiado entre o meta espetador, propenso a aderir em maior grau aos metafilmes, e o meta realizador, inclinado a construir uma carreira em torno da execução dos mesmos. Em causa está o visionamento e o fabrico de obras, direta ou indiretamente, especializadas no universo cinematográfico. A mediação do dispositivo cinematográfico na projeção em sala ou a apropriação de novas e cada vez mais versáteis tecnologias de captação e reprodução audiovisual permite transformar o vidente cinéfilo num utilizador compulsivo, conferindo ao cinema atualmente uma dimensão háptica que ele não detinha da mesma forma anteriormente. O espetador apropria-se de obras criadas por outrem, atribuindo-lhes uma nova forma e um novo sentido, mas dentro de um contexto cinéfilo. Inversamente, o criador é voluntariamente apropriado pela indústria, permitindo o consumo de si mesmo nas edições em videograma e trabalhando internamente as obras e os seus mecanismos formais e narrativos para geraram maior e mais multiplicadas formas de consumo junto dos espetadores. Assim se fomenta uma jornada que não é do herói, mas sim do vidente. Para concluir, defende-se que a maior acessibilidade fílmica permitida pela disseminação de novas janelas de consumo cinematográfico incrementa o repeat viewing e uma apropriação cada vez maior das obras, mas em contrapartida, pode desencadear a nulidade do discurso metacinematográfico e o esboroar do metacinema como tal.
Resumo:
A Norma Portuguesa EN 1997-1:2007 - Eurocódigo 7 (EC 7) quando comparada, quer com a versão anterior ENV 1997-1:1994, cujo estatuto foi de pré-norma, quer com a prática tradicional corrente, introduz alterações significativas na abordagem ao dimensionamento geotécnico de estruturas de suporte. Assim, neste trabalho pretende-se aplicar a abordagem por meio de cálculos preconizada na Norma ao caso do dimensionamento de estruturas de suporte rígidas, comparando-a com os critérios tradicionais de dimensionamento utilizados em Portugal. Para tal realizou-se o plano de estudos seguinte: i) recensão bibliográfica síntese sobre o tema; ii) formulação geral do problema da verificação da segurança de estruturas de suporte rígidas de acordo com o preconizado no EC 7 e: iii) desenvolvimento de uma aplicação em Excel para a verificação da segurança daquelas estruturas nos moldes preconizados no EC 7. A folha de cálculo foi utilizada para comparar, através de dois exemplos - um relativo a um muro gravidade, e o outro relativo a um muro em T invertido - as diferenças entre a via tradicional e o EC 7 no respectivo dimensionamento.
Resumo:
Reinforcement Learning is an area of Machine Learning that deals with how an agent should take actions in an environment such as to maximize the notion of accumulated reward. This type of learning is inspired by the way humans learn and has led to the creation of various algorithms for reinforcement learning. These algorithms focus on the way in which an agent’s behaviour can be improved, assuming independence as to their surroundings. The current work studies the application of reinforcement learning methods to solve the inverted pendulum problem. The importance of the variability of the environment (factors that are external to the agent) on the execution of reinforcement learning agents is studied by using a model that seeks to obtain equilibrium (stability) through dynamism – a Cart-Pole system or inverted pendulum. We sought to improve the behaviour of the autonomous agents by changing the information passed to them, while maintaining the agent’s internal parameters constant (learning rate, discount factors, decay rate, etc.), instead of the classical approach of tuning the agent’s internal parameters. The influence of changes on the state set and the action set on an agent’s capability to solve the Cart-pole problem was studied. We have studied typical behaviour of reinforcement learning agents applied to the classic BOXES model and a new form of characterizing the environment was proposed using the notion of convergence towards a reference value. We demonstrate the gain in performance of this new method applied to a Q-Learning agent.
Resumo:
Mestrado em Segurança e Higiene no TRabalho.
Resumo:
We present new Rayleigh-wave dispersion maps of the western Iberian Peninsula for periods between 8 and 30 s, obtained from correlations of seismic ambient noise, following the recent increase in seismic broadband network density in Portugal and Spain. Group velocities have been computed for each station pair using the empirical Green's functions generated by cross-correlating one-day-length seismic ambient-noise records. The resulting high-path density allows us to obtain lateral variations of the group velocities as a function of period in cells of 0.5 degrees x 0.5 degrees with an unprecedented resolution. As a result we were able to address some of the unknowns regarding the lithospheric structure beneath SW Iberia. The dispersion maps allow the imaging of the major structural units, namely the Iberian Massif, and the Lusitanian and Algarve Meso-Cenozoic basins. The Cadiz Gulf/Gibraltar Strait area corresponds to a strong low-velocity anomaly, which can be followed to the largest period inverted, although slightly shifted to the east at longer periods. Within the Iberian Massif, second-order perturbations in the group velocities are consistent with the transitions between tectonic units composing the massif. (C) 2013 Elsevier B.V. All rights reserved.
Resumo:
In this paper, the design of low profile antennas by using Electromagnetic Band Gap (EBG) structures is introduced. Taking advantage of the fact that they can behave as Perfect Magnetic Conductor (PMC), it is shown that these structures exhibit dual band in-phase reflection at WLAN (Wireless Local Area Network) bands, the 2.4 GHz and 5.2 GHz bands. These structures are applied to PIFA (Planar Inverted-F Antenna) and the results show that it is possible to obtain low profile PIFA's.
Resumo:
The human eukaryotic release factor 3a (eRF3a), encoded by the G1 to S phase transition 1 gene (GSPT1; alias eRF3a), is upregulated in various human cancers. GSPT1 contains a GGCn polymorphism in exon 1, encoding a polyglycine expansion in the N-terminal of the protein. The longer allele, GGC12, was previously shown to be associated to cancer. The GGC12 allele was present in 2.2% of colorectal cancer patients but was absent in Crohn disease patients and in the control group. Real-time quantitative RT-PCR analysis showed that the GGC12 allele was present at up to 10-fold higher transcription levels than the GGC10 allele (P < 0.001). No GSPT1 amplifications were detected, and there was no correlation between the length of the alleles and methylation levels of the CpG sites inside the GGC expansion. Using flow cytometry, we compared the levels of apoptosis and proliferation rates between cell lines with different genotypes, but detected no significant differences. Finally, we used a cytokinesis-block micronucleus assay to evaluate the frequency of micronuclei in the same cell lines. Cell lines with the longer alleles had higher frequencies of micronuclei in binucleated cells, which is probably a result of defects in mitotic spindle formation. Altogether, these findings indicate that GSPT1 should be considered a potential proto-oncogene.
Resumo:
Thymidylate synthase, as a rate-limiting step in DNA synthesis, catalyses the conversion of dUMP into dTMP using 5,10-methylenotetrahydrofolate as the methyl donor. Two polymorphisms have been described in this gene: a repeat polymorphism in the 5' promoter enhancer region (3R versus 2R) and a 6 bp deletion in the 3' unstranslated region. Both of these may affect protein levels. The present case control study was aimed at investigating the influence of these two polymorphisms on the development of colorectal cancer (CRC), as well as their potential interaction with folate, vitamin B6 and vitamin B12 intake. A total of 196 cases and 200 controls, matched for age and sex distribution, were included in the study. No association was found between CRC and the 28 bp repeat polymorphism, but it was observed that individuals with the 6 bp/del and del/del genotypes had a significantly lower risk of developing the disease (OR=0.47; 95% CI 0.30-0.72). A combined genotype (2R/2R; 6 bp/del+del/del) was also found, which was associated with an even lower risk of developing of the disease (OR=0.42; 95% CI 0.26-0.69). No significant interaction between these polymorphisms and vitamin intake was observed. These results indicate for the first time that the 6 bp/del allele might be a protective factor in the development of CRC, independent of the intake of methyl group donors.
Resumo:
Dissertação apresentada na Escola Superior de Educação de Lisboa, para obtenção do grau de Mestre em Ciências da Educação - Especialidade Intervenção Precoce
Resumo:
Dissertação apresentada na Escola Superior de Educação de Lisboa, para obtenção do grau de Mestre em Ciências da Educação Especialidade Intervenção Precoce
Resumo:
Este artigo apresenta parte de um estudo que se encontra a decorrer e que, entre outras questões, procura perceber quais são os processos de raciocínio e as estratégias que são utilizados pelas crianças de um grupo de 4 anos para criar, analisar e generalizar padrões de repetição e de que forma identificam a unidade de repetição de um padrão. Após a implementação das tarefas, podemos concluir que as crianças dominam o conceito de padrão e conseguem criar e analisar padrões de repetição, evoluindo de formas mais simples para formas mais complexas.
Resumo:
Flavour effects due to lepton interactions in the early Universe may have played an important role in the generation of the cosmological baryon asymmetry through leptogenesis. If the only source of high-energy CP violation comes from the left-handed leptonic sector, then it is possible to establish a bridge between flavoured leptogenesis and low-energy leptonic CP violation. We explore this connection taking into account our present knowledge about low-energy neutrino parameters and the matter-antimatter asymmetry observed in the Universe. In this framework, we find that leptogenesis favours a hierarchical light neutrino mass spectrum, while for quasi-degenerate and inverted hierarchical neutrino masses there is a very narrow allowed window. The absolute neutrino mass scale turns out to be m less than or similar to 0.1 eV. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção do grau de mestre em Educação Matemática na Educação Pré-escolar e nos 1º e 2º Ciclos do Ensino Básico
Resumo:
Relatório de Estágio para obtenção do grau de Mestre em Engenharia Civil
Resumo:
This paper presents part of a study that aimed to understand how the emergence of algebraic thinking takes place in a group of four-year-old children, as well as its relationship to the exploration of children‘s literature. To further deepen and guide this study the following research questions were formulated: (1) How can children's literature help preschoolers identify patterns?; (2) What strategies and thinking processes do children use to create, analyze and generalize repeating and growing patterns?; (3) What strategies do children use to identify the unit of repeat of a pattern? and (4) What factors influence the identification of patterns? The paper focuses only on the strategies and thinking processes that children use to create, analyze and generalize repeating patterns. The present study was developed with a group of 14 preschoolers in a private school in Lisbon, and it was carried out with all children. In order to develop the research, a qualitative research methodology under the interpretive paradigm was chosen, emphasizing meanings and processes. The researcher took the dual role of teacher-researcher, conducting the study with her own group and in her own natural environment. Participant observation and document analysis (audio and video recordings, photos and children productions) were used as data collection methods. Data collection took place from October 2013 to April 2014. The results of the study indicate that children master the concept of repeating patterns, and they are able to identify the unit of repeat, create and analyze various repeating patterns, evolving from simpler to more complex forms.