Fibra de crital fotônico: fundamentação e aplicações

The main purpose of this dissertation, consists of the study and analysis of the PBG (Photonic Band Gap )..tecnology incorporated in optical fiber structures. So, we'l1 present a complete PBG structure theory, and folowing this, we'l1 present also a chapter for convencional optical fiber, due to the need to construct the base theory of them, and latter a more complete work about photonic crystal fiber. Finaly, we'l1 show the results of the signals , dispersion, and obtained curves under the right dimensions according to the required signals, for convencional optical and photonic crystal fiber. Knowing that PBG crystals with low losses act as perfect mirrors for forbidden frequences and knowing that the persence of structures of PBG as substrates, brings some desirable characteristics such as spontaneous emition supression and superficial waves. We' 11 show according to these characteristics its applications in telecomunication. Therefore, the enphasis of this work is to show that the optical fibers are the only practible thing to integrate the enormous quantity of data and video at intemet' s market, developing, manipulating, changing, and multiplexing the optical fibers chanels in an area where we expect that the photonic crystals has an important hole, since the photonic crystals can be projected and made to avoid losses in the bands of certain wavelength which permits the increase in efficiency ofthe optical components projected with crystals. A sequence of this work would be the utilisation of the PBG structures in the new system of optical network without fiber developed by Bell laboratories of the lucent tecnology, last year using light rays for transmiting information through the air. The new system of optical networks without fiber will permit sending the data of 15 cd-rooms in less then one second, what represents 65 times more information than those transmitted through the actual radio frequences

Planejamento cooperativo de tarefas em um ambiente de futebol de robôs

Este trabalho apresenta o desenvolvimento de um método de coordenação e cooperação para uma frota de mini-robôs móveis. O escopo do desenvolvimento é o futebol de robôs. Trata-se de uma plataforma bem estruturada, dinâmica e desenvolvida no mundo inteiro. O futebol de robôs envolve diversos campos do conhecimento incluindo: visão computacional, teoria de controle, desenvolvimento de circuitos microcontrolados, planejamento cooperativo, entre outros. A título de organização os sistema foi dividido em cinco módulos: robô, visão, localização, planejamento e controle. O foco do trabalho se limita ao módulo de planejamento. Para auxiliar seu desenvolvimento um simulador do sistema foi implementado. O simulador funciona em tempo real e substitui os robôs reais. Dessa forma os outros módulos permanecem praticamente inalterados durante uma simulação ou execução com robôs reais. Para organizar o comportamento dos robôs e produzir a cooperação entre eles foi adotada uma arquitetura hierarquizada: no mais alto nível está a escolha do estilo de jogo do time; logo abaixo decide-se o papel que cada jogador deve assumir; associado ao papel temos uma ação específica e finalmente calcula-se a referência de movimento do robô. O papel de um robô dita o comportamento do robô na dada ocasião. Os papéis são alocados dinamicamente durante o jogo de forma que um mesmo robô pode assumir diferentes papéis no decorrer da partida

Análise do desempenho térmico de sistema constutivo de concreto com EPS como agregado graúdo

In the last decades there was a concentrate effort of researchers in the search for options to the problem of the continuity of city development and environmental preservation. The recycling and reuse of materials in industry have been considerate as the best option to sustainable development. One of the relevant aspects in this case refers to the rational use of electrical energy. At this point, the role of engineering is to conceive new processes and materials, with the objective of reducing energy consumption and maintaining, at the same time the benefits of the technology. In this context, the objective of the present research is to analyze quantitatively the thermal behavior of walls constructed with concrete blocks which composition aggregates the expanded polystyrene (EPS) reused in the shape of flakes and in the shape of a board, resulting in a “light concrete”. Experiments were conducted, systematically, with a wall (considerate as a standard) constructed with blocks of ordinary concrete; two walls constructed with blocks of light concrete, distinct by the proportion of EPS/sand; a wall of ceramic bricks (“eight holes” type) and a wall with ordinary blocks of cement, in a way to obtain a comparative analysis of the thermal behavior of the systems. Others tests conducted with the blocks were: stress analysis and thermal properties analysis (ρ, cp e k). Based on the results, it was possible to establish quantitative relationship between the concentration (density) of EPS in the constructive elements and the decreasing of the heat transfer rate, that also changes the others thermal properties of the material, as was proved. It was observed that the walls of light concrete presents better thermal behavior compared with the other two constructive systems world wide used. Based in the results of the investigation, there was shown the viability of the use of EPS as aggregate (raw material) in the composition of the concrete, with the objective of the fabrication of blocks to non-structural masonry that works as a thermal insulation in buildings. A direct consequence of this result is the possibility of reduction of the consume of the electrical energy used to climatization of buildings. Other aspect of the investigation that must be pointed was the reuse of the EPS as a raw material to civil construction, with a clear benefit to reducing of environmental problems

Clássicos versus Keynes: a abordagem formal de David Champernowne

Este texto tem por objetivo ressaltar um aspecto que não tem sido tratado com a devida profundidade na literatura que estuda a formalização da Teoria Geral do Emprego, dos Juros e da Moeda de John Maynard Keynes (1936). Mais precisamente, o texto destaca a estratégia de formalização adotada por David G. Champernowne em seu artigo intitulado Unemployment, Basic and Monetary: the classical analysis and the keynesian, publicado em 1935-36 na Review of Economic Studies. Chamamos a atenção para o fato dele distinguir a teoria clássica da teoria de Keynes não apenas pelos pressupostos adotados por cada teoria, mas principalmente pela construção de subsistemas a partir de um sistema geral, com características recursivas (relações de causalidade) distintas. As explicações em prosa, a descrição algébrica das funções comportamentais e condições de equilíbrio e a ilustração por meio de diagramas, além da escolha de conjuntos específicos de variáveis para representar cada uma das teorias e suas diferentes versões são aspectos deste artigo de Champernowne que merecem uma análise mais minuciosa.

A Compreensão da idéia do número racional e suas operações na EJA: uma forma de inclusão em sala de aula

The awareness of the difficulty which pupils, in general have in understanding the concept and operations with Rational numbers, it made to develop this study which searches to collaborate for such understanding. Our intuition was to do with that the pupils of the Education of Young and Adults, with difficulty in understanding the Rational numbers, feel included in the learning-teaching process of mathematics. It deals with a classroom research in a qualitative approach with analysis of the activities resolved for a group of pupils in classroom of a municipal school of Natal. For us elaborate such activities we accomplished the survey difficulties and obstacles that the pupils experience, when inserted in the learning-teaching process of the Rational numbers. The results indicate that the sequence of activities applied in classroom collaborated so that the pupils to overcome some impediments in the learning of this numbers

A difícil aceitação dos números negativos: um estudo da teoria dos números de Peter Barlow (1776-1862)

The present study seeks to present a historico-epistemological analysis of the development of the mathematical concept of negative number. In order to do so, we analyzed the different forms and conditions of the construction of mathematical knowledge in different mathematical communities and, thus, identified the characteristics in the establishment of this concept. By understanding the historically constructed barriers, especially, the ones having ontologicas significant, that made the concept of negative number incompatible with that of natural number, thereby hindering the development of the concept of negative, we were able to sketch the reasons for the rejection of negative numbers by the English author Peter Barlow (1776 -1862) in his An Elementary Investigation of the Theory of Numbers, published in 1811. We also show the continuity of his difficulties with the treatment of negative numbers in the middle of the nineteenth century

Teoria histórico-cultural e suas implicações na atuação do professor de educação física escolar

This article presents a theoretical search and aims to introduce the main categories of historical-cultural theory and discuss its implications for the physical education teacher's work inside the school and also emphasizes this theory and its methodological proposal as an important way to build the scholar physical education in a critical perspective aiming to change the school and the students conscious and personality. The Vigotskian school of human development it is taken as an important reference to understand the scholars in their vital process of development and helps the teachers in general, and physical education teachers in specific, to consider the activity ( vital activity) as important instrument to get the humanization and liberty of human being, inside the school and inside the contemporary society.

Efeitos de sentido das não coincidências do dizer na escrita acadêmica

Universidade Federal do Rio Grande do Norte

Infografia interativa na redação: o processo de produção no Diário do Nordeste à luz da teoria do jornalismo

The infographics historically experience the process of evolution of journalism, from the incipient models handmade in the eighteenth century to the inclusion of computers and sophisticated software today. In order to face the advent of TV against of the partiality readers of the printed newspaper, or to represent the Gulf War, where not allowed photography, infographics reaches modern levels of production and publication. The technical devices which enabled the infographics to evolve the environment of the internet, with conditions for the manipulation of the reader, incorporating video, audio and animations, so styling of interactive infographics. These digital models of information visualization recently arrived daily in the northeast and on their respective web sites with features regionalized. This paper therefore proposes to explore and describe the processes of producing the interactive infographics, taking the example of the Diário do Nordeste, Fortaleza, Ceará, whose department was created one year ago. Therefore, based on aspects that guide the theory of journalism, as newsmaking, filters that focus on productive routine (gatekeeping) and the construction stages of the news. This research also draws on the theoretical framework on the subject, in concepts essential characteristics of computer graphics, as well as the methodological procedures and systematic empirical observations in production routines of the newsroom who can testify limitations and / or advances

Publicidade e moda: um estudo sobre a materialidade da mídia e a produção de sentido na revista ffw>>mag!

The proposal of this research is to analyze the convergence between fashion and communication shown on the materiality of the print media, and how the language from the supporter influences on the production of sense by the target market. Made real in the research corpus comprised of six ffw>>mag! magazines from the year 2011. The applied conceptual mechanism tries to investigate the production of sense from the physical attributes before interpreting the message s content, to do so, the Materiality of Communication is used, which offers an investigative apparatus of the media in its material shape, and those as influences in the communicative acts and processes. Methodologically, we adopt the Peircean Semiotics Theory, for its study focus on the analysis of the possible processes of production of sense. Through Semiotics we achieve the interpretative levels that allow us to clarify the questionings that come from the research s objectives, identifying and tracing the cognitive and intelligibility schemes bound to the media speeches of materiality. The analysis coordinated to the concepts and theories employed in this study point to a confirmation that the materiality of the reviewed media communicates to the readers in the same intensity as its content, provides a preview of the content and notifies the intentions of the publication. In the commercial way, characterizing the target audience it craves, and also in the conceptual way, demonstrating the ideas it wants to communicate. Where the convergence between communication and fashion unfolds as the materiality of the media by the choice of the materials and finishing options, and mainly by the selection and manipulation of technical images and colors from the cycles of fashion

Aplicações da teoria da percolação à modelagem e simulação de reservatórios de petróleo

In this thesis we study some problems related to petroleum reservoirs using methods and concepts of Statistical Physics. The thesis could be divided percolation problem in random multifractal support motivated by its potential application in modelling oil reservoirs. We develped an heterogeneous and anisotropic grid that followin two parts. The first one introduce a study of the percolations a random multifractal distribution of its sites. After, we determine the percolation threshold for this grid, the fractal dimension of the percolating cluster and the critical exponents ß and v. In the second part, we propose an alternative systematic of modelling and simulating oil reservoirs. We introduce a statistical model based in a stochastic formulation do Darcy Law. In this model, the distribution of permeabilities is localy equivalent to the basic model of bond percolation

Um estudo na teoria do movimento brownianno com viscosidade variável

In this work we investigate the stochastic behavior of a large class of systems with variable damping which are described by a time-dependent Lagrangian. Our stochastic approach is based on the Langevin treatment describing the motion of a classical Brownian particle of mass m. Two situations of physical interest are considered. In the first one, we discuss in detail an application of the standard Langevin treatment (white noise) for the variable damping system. In the second one, a more general viewpoint is adopted by assuming a given expression to the so-called collored noise. For both cases, the basic diffententiaql equations are analytically solved and al the quantities physically relevant are explicitly determined. The results depend on an arbitrary q parameter measuring how the behavior of the system departs from the standard brownian particle with constant viscosity. Several types of sthocastic behavior (superdiffusive and subdiffusive) are obteinded when the free pamameter varies continuosly. However, all the results of the conventional Langevin approach with constant damping are recovered in the limit q = 1

Teoria cinética não extensiva: efeitos físicos em gases e plasmas

The standard kinetic theory for a nonrelativistic diluted gas is generalized in the spirit of the nonextensive statistic distribution introduced by Tsallis. The new formalism depends on an arbitrary q parameter measuring the degree of nonextensivity. In the limit q = 1, the extensive Maxwell-Boltzmann theory is recovered. Starting from a purely kinetic deduction of the velocity q-distribution function, the Boltzmann H-teorem is generalized for including the possibility of nonextensive out of equilibrium effects. Based on this investigation, it is proved that Tsallis' distribution is the necessary and sufficient condition defining a thermodynamic equilibrium state in the nonextensive context. This result follows naturally from the generalized transport equation and also from the extended H-theorem. Two physical applications of the nonextensive effects have been considered. Closed analytic expressions were obtained for the Doppler broadening of spectral lines from an excited gas, as well as, for the dispersion relations describing the eletrostatic oscillations in a diluted electronic plasma. In the later case, a comparison with the experimental results strongly suggests a Tsallis distribution with the q parameter smaller than unity. A complementary study is related to the thermodynamic behavior of a relativistic imperfect simple fluid. Using nonequilibrium thermodynamics, we show how the basic primary variables, namely: the energy momentum tensor, the particle and entropy fluxes depend on the several dissipative processes present in the fluid. The temperature variation law for this moving imperfect fluid is also obtained, and the Eckart and Landau-Lifshitz formulations are recovered as particular cases

Teoria semi-clássica para super rede magnética formada por materiais ferromagnético e antiferromagnético

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Contribuições da teoria histórico-cultural para o processo de avaliação psicoeducacional

Cet article a comme objectif présenter la contribution de la Psychologie Historique-Culturelle pour l'analyse critique de l'évaluation psychoéducationnel traditionnel et postuler les fondements pour la nouvelle modalité évaluative. Cette proposition se justifie à cause de l'actuelle révitalisation de l'usage des testes padronisés pour la mensuration des fonctions psychologiques, dues à la vulgarisation de la neuropsychologie. Historiquement les testes padronisés servent comme instrument pour attester cientifiquement l'idéologie de l'égalité entre les hommes dans la societé capitaliste que se maintient à travers de l'expropriation et de l'exclusion. En outre, il existe une forte tendence à attendre que les résultats expliquent l'intelligence comme inée ou considèrent les prédispositions héréditaires pour apprendre, ce qu'on oppose à la comprehénsion que les fonctions mentales sont formées dans le proccès de développement historique-social à travers l'appropriation de la culture humaine. Il est nécessaire donc une évaluation qui considère les médiations sociales (des instruments et des signes) comme constituants des fonctions psychologiques encourageant le développement de tous les individus et la non légitimation de l'exclusion sociale.