Estratégias baseadas em aprendizado para coordenação de uma frota de robôs em tarefas cooperativas

In multi-robot systems, both control architecture and work strategy represent a challenge for researchers. It is important to have a robust architecture that can be easily adapted to requirement changes. It is also important that work strategy allows robots to complete tasks efficiently, considering that robots interact directly in environments with humans. In this context, this work explores two approaches for robot soccer team coordination for cooperative tasks development. Both approaches are based on a combination of imitation learning and reinforcement learning. Thus, in the first approach was developed a control architecture, a fuzzy inference engine for recognizing situations in robot soccer games, a software for narration of robot soccer games based on the inference engine and the implementation of learning by imitation from observation and analysis of others robotic teams. Moreover, state abstraction was efficiently implemented in reinforcement learning applied to the robot soccer standard problem. Finally, reinforcement learning was implemented in a form where actions are explored only in some states (for example, states where an specialist robot system used them) differently to the traditional form, where actions have to be tested in all states. In the second approach reinforcement learning was implemented with function approximation, for which an algorithm called RBF-Sarsa($lambda$) was created. In both approaches batch reinforcement learning algorithms were implemented and imitation learning was used as a seed for reinforcement learning. Moreover, learning from robotic teams controlled by humans was explored. The proposal in this work had revealed efficient in the robot soccer standard problem and, when implemented in other robotics systems, they will allow that these robotics systems can efficiently and effectively develop assigned tasks. These approaches will give high adaptation capabilities to requirements and environment changes.

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

Construção e análise de desempenho de um fogão solar à concentração utilizando dois focos para cozimento direto

A model of a solar oven with a reflective surface composed of two mirror segments is presented, constituting a two semi-parabolic surfaces made of fiberglass, applied on a ceramic mold, intended to be used in residential and commercial cooking. The reflective surface of the semi-parable is obtained with the use of multiple plain segments of 2 mm wide mirrors. The semi-parabolic structure has visible movements that are comparable to that of the sun. The technical details of the manufacturing and assembling processes will be presented with an analysis of the viability of thermal, economic, and materials of such prototype. This prototype has important social implications and primordial aspects, which combats the ecological damages caused by the wide-scale use of firewood during cooking. It has been demonstrated that the solar oven has the capacity to cook simultaneous two meals distinct for a family of four

Análise tribológica das malhas multifuncionais obtidas por multicamadas

The present work consists in the analysis of tribologycal properties of basic and multifunctional knitted fabrics. This knowledge has fundamental importance for the textile industry since it can quantify, in an objective way, the tactil. The fabrics used were characterized by friction and mechanical tests for determining the viscoelastic region, wear resistance and friction coefficient of the fabrics used. The stress-strain curve was obtained by the method Kawabata, KES-FB1. Wear tests performed with the aid of equipment Martindale. The measurement of friction coefficient, two methods were used and analyzed comparatively. The first was a method already established worldwide known as KES-FB4 and the second was an innovative method called FRICTORQ, developed by the University of Minho. These two methods were compared taking into account the relative motion between the tribologycal pairs are different from each method. While the first motion is translational, the second is rotational. It was formal that the knitted had a multifunctional fabrics tribologycal performance which was better than the basic knitted fabrics, as the viscoelastic region, was laager highlighting a multifunctional structure, with greater wear resistance mainly on the back side of the knitted fabrics and lower friction coefficient. Performing a comparative analysis between two methods used to measure the friction coefficient, it was formal that both methods were consistent in terms of results. In operational terms, the FRICTORQ showed ease of operation and increased reproducibility of results

Simulação computacional do escoamento em bombas de cavidades progressivas

The use of Progressing Cavity Pumps (PCPs) in artificial lift applications in low deep wells is becoming more common in the oil industry, mainly, due to its ability to pump heavy oils, produce oil with large concentrations of sand, besides present high efficiency when compared to other artificial lift methods. Although this system has been widely used as an oil lift method, few investigations about its hydrodynamic behavior are presented, either experimental or numeric. Therefore, in order to increase the knowledge about the BCP operational behavior, this work presents a novel computational model for the 3-D transient flow in progressing cavity pumps, which includes the relative motion between rotor and stator, using an element based finite volume method. The model developed is able to accurately predict the volumetric efficiency and viscous looses as well as to provide detailed information of pressure and velocity fields inside the pump. In order to predict PCP performance for low viscosity fluids, advanced turbulence models were used to treat, accurately, the turbulent effects on the flow, which allowed for obtaining results consistent with experimental values encountered in literature. In addition to the 3D computational model, a simplified model was developed, based on mass balance within cavities and on simplification on the momentum equations for fully developed flow along the seal region between cavities. This simplified model, based on previous approaches encountered in literature, has the ability to predict flow rate for a given differential pressure, presenting exactness and low CPU requirements, becoming an engineering tool for quick calculations and providing adequate results, almost real-time time. The results presented in this work consider a rigid stator PCP and the models developed were validated against experimental results from open literature. The results for the 3-D model showed to be sensitive to the mesh size, such that a numerical mesh refinement study is also presented. Regarding to the simplified model, some improvements were introduced in the calculation of the friction factor, allowing the application fo the model for low viscosity fluids, which was unsuccessful in models using similar approaches, presented in previous works

Análise tribológica de um sistema de acionamento alternativo de pigs para a indústria do petróleo

It is analyzed through the concepts of tribology and mechanical contact and damage the suggestion of implementing a backup system for traction and passage of Pipeline Inspection Gauge (Pig) from the inside of pipelines. In order to verify the integrity of the pipelines, it is suggested the possibility of displacement of such equipment by pulling wires with steel wires. The physical and mechanical characteristics of this method were verified by accelerated tests in the laboratory in a tribological pair, wire versus a curve 90. It also considered the main mechanisms of wear of a sliding system with and without lubricant, in the absence and presence of contaminants. To try this, It was constructed a test bench able to reproduce a slip system, work on mode back-and-forth ("reciprocation"). It was used two kinds of wires, a galvanized steel and other stainless steel and the results achieved using the two kinds of steel cables were compared. For result comparative means, it was used steel cables with and without coating of Poly Vinyl Chloride (PVC). The wires and the curves of the products were characterized using metallographic analysis, microhardness Vickers tests, X-ray diffraction (XRD), X-Ray Refraction (XRF) and tensile tests. After the experiments were analyzed some parameters that have been measurable, it demonstrates to the impracticality of this proposed method, since the friction force and the concept of alternating request at the contact between the strands of wire and the inner curves that are part ducts caused severe wear. These types of wear are likely to cause possible failures in future products and cause fluid leaks

Objetivos e conteúdos no ensino de física para adultos: um estudo de caso

The dissertation presents the learning, production and results of a study with a group of adult students of a high school level class in a night time public school at the Zona Oeste district of Natal-RN. As a teacher of Physics of these adult students, whose age is between 17 and 65 years, we felt the need to deepen our knowledge about the specifics of these students and build ways of teaching which would lead to a more significant educational process beside them. Among these ways of teaching, we emphasize, first, the performance of an extra-class activity that triggered the students' oral narratives about their life stories. Such narratives have led us to prioritize, as goals of teaching: socialization and the rescue of the search for a permanent learning, self-esteem and skills development to promote the exercise of autonomy. The students' previous contacts with the country life showed to be extremely significant for their memories and motives, suggesting the theme "Nature" to be adopted as a matrix for generative themes to be adopted during the teaching and learning moments with them. Considering these results, we construct a teaching proposal for continued work with the class, with which we chose the "Climate" as a guiding theme of this proposal, here presented and analyzed. In addition to a movement between problematizations developed in a thematic framework - through the initial questions of the students -, and those in a more conceptual approach - that we induced -, we have adopted as central methodological aspect the use of oral and written language, both as an exercise of dialogue, Freire's perspective, such as a structural element of cognitive processes, the perspectives of Vygotsky and Bakhtin. The development of the proposal was registered by audio and teacher and students´ regular written records, for 1 month and a half. As positive outcomes of the proposal, we emphasize the changing attitudes of students, showing a significant increase of their initiative in participating of the classes, besides a creative and critical use of arguments during the situations studied

O Barroco Hispano-americano: primero sueño ou Sor Juana Inés de La Cuz

The current dissertation is linked to the research line Poéticas da modernidade e da pós-modernidade (modern and post modern poetics), which is being developed for the Programa de Pós-graduação em Estudos da Linguagem (Program of post graduation in language studies), in the area of Literatura Comparada (comparative literature) CCHLA/UFRN. The main aim of the research is to show the reading of Primero sueño by sor Juana Inés de la Cruz, in the middle of the contemporary age, through an eclectic analysis which elucidates the baroque in its most recent concept; the social context and the life as a nun of sor Juana and the analysis of the poetry starting from the glance to the literary text. The perception of the baroque eon universal as a constant artistic movement from its appearance to the present time thus highlighted based on the most modern studies by the baroque specialists: Eugênio d Ors, O barroco (s/d), Severo Sarduy, Barroco (s/d) and Gilles Deleuze, A dobra: Leibniz e o barroco (1991). In that research, it will be presented the translation/transcreation of the study object corpus still guided by the translatological theories of Haroldo de Campos (2004), Da tradução como criação e como crítica, Walter Benjamin (1971), A tarefa do tradutor and Jacques Derrida (2006), Torres de Babel

Indícios sincrônicos de gramaticalização: o uso do verbo chegar em orações coordenadas e na perífrase verbal [chegar (e) + v2]: contribuições para o ensino de gramática.

Based on North American Functional Linguistic Theory, our proposal is to describe and analyze the use of verb CHEGAR in verbal periphrasis such as [CHEGAR (E) + V2], where CHEGAR does not demonstrate a significance linked to physical movement. In linguistic literature, such periphrasis has been attributed several functions, related to aspectualization, emphasis of negative segments, and construction of mental spaces, among others. This study considers that the function of verb CHEGAR in the periphrasis in question is to indicate a global aspect, emphasizing a range of semantic-pragmatic nuances such as the sudden, instantaneous, or even abrupt character of the events refered to by the principal verb of the construction (V2), and/or the taking of initiative (sudden) by the agent (in the syntactic role of periphrastic subject), and/or subjective evaluations which go from surprise to frustration. Our objectives are the following: i) to describe and analyze the semanticpragmatic, morphosyntactic and social relationships which characterize the use of CHEGAR in verbal periphrases like [CHEGAR (E) + V2] and in coordinated/juxtaposed speech in which CHEGAR is the principal verb of the first utterance and is an elocution verb and the principal verb of the second; ii) identify, based on this description and analysis, synchrony proof in the grammaticalization of CHEGAR as an auxiliary verb in the periphrasis refered to. There was observed to be a strong similarity between coordinate/juxtaposed and periphrastic constructions. Such similarities strengthen the hypothesis that the use of CHEGAR as a lexical verb in coordinate/juxtaposed structures is the origin of the use of CHEGAR in the periphrastic structure, since the many properties encountered with higher frequency in lexical use are also just as frequently used as auxiliaries. Nevertheless, between the two constructions being studied, sufficient difference can be observed to see that CHEGAR, in the periphrasis [CHEGAR (E) V2], is behaving like an auxiliary verb, and shows typical properties of these types of verbs: i) in 100% of occurrences, it does not have a complement;ii) it has a co-referential subject in 100% of cases; iii) it does not appear with intervening material between it and V2. Besides this, CHEGAR, in periphrases, is predominant in nonneutral evaluation contexts, denoted by V2. Inspired by the results obtained, we propose strategies for the discussion of the [CHEGAR (E) V2] periphrases in both elementary and high schools.

O evangelho por escrever: uma leitura do desassossego nos fragmentos de Bernardo Soares.

Cette recherche a pour but d approfondir des études qui mettent en lumière des particularités inhérentes au processus de l écriture fragmentaire. Notre intérêt pour ce thème provient de la poétique fragmentaire du Le livre de l intranquillité composé par Bernardo Soares, assistant de notaire et sémi-hétéronime de l écrivain Fernado Pessoa. Notre approche de ce genre textuel commencera par une méthodologie comparative qui nous donnera des notions pour que nous puissions établir quelques rapports de ressemblances et différences entre fragments, maximes, aphorismes et réflexions dont le corpus littéraire sera le journal intime de l intranquilité soarianne, ainsi que la fragmentation du simulacre d auteur au cours des années pendant lesquelles le Livre a été écrit. Le livre de l intranquillité lance des « pulvérisations » réflexives, lesquelles demeurent actuelles, étant donné que le processus de l écriture fragmentaire semble être toujours dans un mouvement constant et, donc, dans l ambiance du à venir. À partir de cela, nous avons passés pour quelques entraves pour essayer d établir une définition pour ce qui serait l écriture fragmentaire. Nous chercherons des points d intersection visant à établir des paradigmes pour obtenir des notions plus précises sur ce genre textuel, concernant les maximes, aphorismes et sentences refléxives.

O complemento de lugar dos verbos de movimento: implicações para o ensino de língua materna

Conselho Nacional de Desenvolvimento Científico e Tecnológico

O Uso de operações linguístico-discursivas da crítica genética na reescritura de textos

As a professor in Curso de Licenciatura em Letras, from Campus Avançado Profa Maria Eliza Albuquerque Maia (CAMEAM),do Estado do Estado do Rio Grande do Norte (UERN), in the town of Pau do Ferros, in the state of Rio Grande do Norte, we had the chance to carry out several writing activities , as well as guiding re-writing activities for the texts produced. From this experience, we started looking at the need of reflecting upon the writing process in higher education. Thus, we aim at analyzing, in this research, the methodology used in the moment of carrying out the writing practices activities in higher education, investigating, in particular, the rewriting practices, concerning the operations used for carrying out such activities, as well as the sense effects produced from the alterations which were made in the texts. Our theoretical foundation is grounded on a conception of text as a verbal action , what reveals a socio-interactional view of the language (MARCUSCHI, 2008; SAUTCHUK, 2003). As the production of written texts, our research focus, we assume that, for this activity, we deal with distinct figures (active writer and internal reader), so that we can, apart from writing, reflecting upon our writing and, this way, deciding about operations which are carried out to make the alterations which are necessary to the rewriting of our texts (SAUTCHUK, 2003). Still about the theoretical foundations used in this research, we made use of the theories from the Textual Analysis of Discourse (TAD) which discusses the belief on the evidence on the existence of the texts, which is opposite to the fixist view of textuality which believes that the texts exist by themselves. (ADAM, 2008; [2005]2010). Under this perspective, we have also adopted, the concepts which come from genetics criticism which is concerned about the relation between text and genesis, using as objects documents which bring traits of the text in progress, on the ground that the text is the result of work in progress, and the writing practice, on the other hand, as an activity in a continuous movement (HAY, [1975]2002; DE BIASI, [2000]2010; GRÉSILLON, 1989; [1990]2008; [1992]2002; SALLES, 2008a). The methodology in this research is an ethnography-based one, an approach which focuses on the process, as well as is meaning-based. To understand the objectives proposed in our research, we made use of different procedures of collecting data which include an ethnographic study, such as: observation, note-taking, document analysis. The data which were analyzed were collected during the semester of 2008.2, in a first term classroom of Curso de Letras from CAMEAM, when we were able to collect twenty-one written texts and all of them were rewritten based on rewriting activities, what provides a corpus of forty-two texts which will be analyzed based on the linguistics operations identified by Generative Grammar and adopted by Lebrave and Grésillon (2009). From these analyses, we were able to confirm that writing is a process, and rewriting has become an extremely important activity for this process. Still due to these data, we observed that substitution was the most used operation by text authors. We believe that this result is justified by the fact that the substitution, according to what proposes the Genetic Criticism, constitutes the source of all erasure, from which one can easily make a change in writing. Regarding the operations of addition and deletion, we found that they were used in quantitative terms, almost equivalently, which can be explained when we see that the two operations require, by the author of the text, different strategies from those used for the replacement, what includes , respectively, adding or removing a segment. Finally, we found out that the shift operation was the least used, since it works with a segment that will not be replaced, added or deleted, but transferred to another place of text, which requires a greater ability of the author to perform this operation and not compromising the meaning of his/her writing. As a result, we hope to contribute to the reflection on the teaching of writing, considering, in a particular way, those with a Bachelor in Arts. Our analysis will contribute to the teaching of Portuguese language, specifically for activities that guide the production of texts in order to explore with students the ability to rewrite their own text

O Brasil n o berço da desigualdade: uma abordagem analítica sobre os significados das fotografias de Sebastião Salgado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Eleutheria: a noção de liberdade na ética de Epicuro

Épicure de Samos (341-270 a.C) fut l'un des plus importants penseurs de l'Antiquité. Le philosophe du Jardin, comme il a été connue, aurait écrit au moins 300 volumes. Ayant vécu dans une Grèce sans l'autonomie des temps passés, a vu l'atténuation du sens de liberté (eleutheria) dans le domaine social. En outre, la théorie atomiste que lui précédée et lui a influencée postulais un déterminisme qui avait entraîné la fatalité et l'élimination des eleutheria aussi dans le domaine de la nature (physis). Dans ce contexte, il donne, de la physiología, une forme originale à l'étude de la physis, afin de postuler l'existence du hasard (tychè) agissant dans le monde phisique et de la liberté, dans l‟action humaine. S‟il fait cela, c‟est parce qu‟il croit que être libre est condition du bonheur et celle-ci réside dans le plaisir. Pour cela, Épicure va présenter l'indéterminisme dans le domaine de la physiologie, garantissant l'existence d'un mouvement de déclinaison de l'atome - le parênklisis. Ainsi, dans ce travail, nous allons effectuer une analyse de la façon de se montrer le sens d‟eleutheria développé dans la pensée de ce maître et comment il interagit avec son projet d'éthique. En particulier, nous discutons de comment, de la physiología, Épicure pense un éthos-llibre tourné vers la réalisation du plaisir, de la vie heureuse. Pour cela, nous utilisons la Lettre à Hérodote, la Lettre à Pítocles, la Lettre à Ménécée, 81 Sentences Vaticanes, 40 Maximes Fondamentales et les rapports doxographie

Dinâmica Estocástica e Cosmologia: alguns resultados analíticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior