Sistema híbrido para detecção e diagnóstico de falhas em sistemas dinâmicos

The industries are getting more and more rigorous, when security is in question, no matter is to avoid financial damages due to accidents and low productivity, or when it s related to the environment protection. It was thinking about great world accidents around the world involving aircrafts and industrial process (nuclear, petrochemical and so on) that we decided to invest in systems that could detect fault and diagnosis (FDD) them. The FDD systems can avoid eventual fault helping man on the maintenance and exchange of defective equipments. Nowadays, the issues that involve detection, isolation, diagnose and the controlling of tolerance fault are gathering strength in the academic and industrial environment. It is based on this fact, in this work, we discuss the importance of techniques that can assist in the development of systems for Fault Detection and Diagnosis (FDD) and propose a hybrid method for FDD in dynamic systems. We present a brief history to contextualize the techniques used in working environments. The detection of fault in the proposed system is based on state observers in conjunction with other statistical techniques. The principal idea is to use the observer himself, in addition to serving as an analytical redundancy, in allowing the creation of a residue. This residue is used in FDD. A signature database assists in the identification of system faults, which based on the signatures derived from trend analysis of the residue signal and its difference, performs the classification of the faults based purely on a decision tree. This FDD system is tested and validated in two plants: a simulated plant with coupled tanks and didactic plant with industrial instrumentation. All collected results of those tests will be discussed

Simulador computacional do comportamento em regime de poços de petróleo equipados com gas-lift contínuo

Amongst the results of the AutPoc Project - Automation of Wells, established between UFRN and Petrobras with the support of the CNPq, FINEP, CTPETRO, FUNPEC, was developed a simulator for equipped wells of oil with the method of rise for continuous gas-lift. The gas-lift is a method of rise sufficiently used in production offshore (sea production), and its basic concept is to inject gas in the deep one of the producing well of oil transform it less dense in order to facilitate its displacement since the reservoir until the surface. Based in the use of tables and equations that condense the biggest number of information on characteristics of the reservoir, the well and the valves of gas injection, it is allowed, through successive interpolations, to simulate representative curves of the physical behavior of the existing characteristic variable. With a simulator that approaches a computer of real the physical conditions of an oil well is possible to analyze peculiar behaviors with very bigger speeds, since the constants of time of the system in question well are raised e, moreover, to optimize costs with assays in field. The simulator presents great versatility, with prominance the analysis of the influence of parameters, as the static pressure, relation gas-liquid, pressure in the head of the well, BSW (Relation Basic Sediments and Water) in curves of request in deep of the well and the attainment of the curve of performance of the well where it can be simulated rules of control and otimization. In moving the rules of control, the simulator allows the use in two ways of simulation: the application of the control saw software simulated enclosed in the proper simulator, as well as the use of external controllers. This implies that the simulator can be used as tool of validation of control algorithms. Through the potentialities above cited, of course one another powerful application for the simulator appears: the didactic use of the tool. It will be possible to use it in formation courses and recycling of engineers

Identificação de modelos polinomiais narx utilizando algoritmos combinados de detecção de estrutura e estimação de parâmetros com aplicações práticas

A modelagem de processos industriais tem auxiliado na produção e minimização de custos, permitindo a previsão dos comportamentos futuros do sistema, supervisão de processos e projeto de controladores. Ao observar os benefícios proporcionados pela modelagem, objetiva-se primeiramente, nesta dissertação, apresentar uma metodologia de identificação de modelos não-lineares com estrutura NARX, a partir da implementação de algoritmos combinados de detecção de estrutura e estimação de parâmetros. Inicialmente, será ressaltada a importância da identificação de sistemas na otimização de processos industriais, especificamente a escolha do modelo para representar adequadamente as dinâmicas do sistema. Em seguida, será apresentada uma breve revisão das etapas que compõem a identificação de sistemas. Na sequência, serão apresentados os métodos fundamentais para detecção de estrutura (Modificado Gram- Schmidt) e estimação de parâmetros (Método dos Mínimos Quadrados e Método dos Mínimos Quadrados Estendido) de modelos. No trabalho será também realizada, através dos algoritmos implementados, a identificação de dois processos industriais distintos representados por uma planta de nível didática, que possibilita o controle de nível e vazão, e uma planta de processamento primário de petróleo simulada, que tem como objetivo representar um tratamento primário do petróleo que ocorre em plataformas petrolíferas. A dissertação é finalizada com uma avaliação dos desempenhos dos modelos obtidos, quando comparados com o sistema. A partir desta avaliação, será possível observar se os modelos identificados são capazes de representar as características estáticas e dinâmicas dos sistemas apresentados nesta dissertação

Dificuldades no processo ensino aprendizagem de trigonometria por meio de atividades

This study analyses the difficulties that teachers of high school face in the process of the teaching of trigonometry through activities in a construtivist focus. It contains a review of some publications and dissertations related with the study of trigonometry elaborated in the last years by several authors. It resorts to the study of teaching engineering as an instrument used in the research. It also presents a set of activities which will serve as sample to other teachers of mathematics; and points ways for the overcome of the difficulties found

Números complexos: uma proposta de mudança metodológica para uma aprendizagem significativa no ensino médio

This work presents a proposal of a methodological change to the teaching and learning of the complex numbers in the Secondary education. It is based on the inquiries and difficulties of students detected in the classrooms about the teaching of complex numbers and a questioning of the context of the mathematics teaching - that is the reason of the inquiry of this dissertation. In the searching for an efficient learning and placing the work as a research, it is presented a historical reflection of the evolution of the concept of complex numbers pointing out their more relevant focuses, such as: symbolic, numeric, geometrical and algebraic ones. Then, it shows the description of the ways of the research based on the methodology of the didactic engineering. This one is developed from the utilization of its four stages, where in the preliminary analysis stage, two data surveys are presented: the first one is concerning with the way of presenting the contents of the complex numbers in math textbooks, and the second one is concerning to the interview carried out with High school teachers who work with complex numbers in the practice of their professions. At first, in the analysis stage, it is presented the prepared and organized material to be used in the following stage. In the experimentation one, it is presented the carrying out process that was made with the second year High school students in the Centro Federal de Educação tecnológica do Rio Grande do Norte CEFET-RN. At the end, it presents, in the subsequent and validation stages, the revelation of the obtained results from the observations made in classrooms in the carrying out of the didactic sequence, the students talking and the data collection

A química no ensino médio e a contextualização: a fabricação dos sabões e detergentes como tema gerador de ensino aprendizagem

El conocimiento químico es muy importante a la comprensión de procesos físicos y químicos que nos acercan, por una opción de una vida mejor con calidad, fomentando y acompañando el desarrollo tecnológico. Sin embargo, la formación de un pensamiento químico fruto de un aprendizaje significativo es hoy, en todo el país, un reto paro los educadores de química. Estúdios señalan la contextualización de los contenidos químicos como recurso para promover una interrelación entre conocimientos escolares y hechos/situaciones presentes en el cotidaiano de los alumnos, añadiendo significado a los contenidos escolares, proporcionando a los alumnos un aprendizaje significativo. Con tal objetivo, la siguiente pesquisa se realizó con la intención de contribuir con la enseñanza de química y con el propósito general de proponer un materila didáctico que presentase una forma contextualizada de trabajar algunos conceptos y contenidos fundamentales a la química, con tema generador de la enseãnaza y aprendizaje a la fabricación de jabones y detergentes. Con objetivo de justificar la elección del planteamiento de la contextualización y la elaboración del material didáctico, se hizo una pesquisa acerca de la enseãnaza de química en al red pública de educación y la relación de ésta con los contextos pertenecentes a la realidad de los alumnos. Se observó que la enseñanza de química actual en la red pública de educación es tradicional y descontextualizada. Los resultados de esta pesquisa muestran la necesidad de cámbios la forma de como se enseñan los contenidos químicos. En la segunda parte de la pesquisa, se produjo la elaboración de la unidad didáctica de enseñanza, con el objetivo de promover el aprendizaje significativo de conocimientos químicos a partir del tema de la fabricación de jabones y detergentes. Se observó que el trabajo alcanzó los objetivos propuestos. Una evaluación cualitativa mostró que los alumnos estuvieron más participativos e interesados al estudiar química de esta forma. Relatos y decalraciones de los alumnos también indicaron que hubo un aprendizaje significativo de los contenidos trabajados y que los alumnos son capaces de transferirlos para la comprensión de situaciones reales. Y una evaluación cuantitativa del material nos reveló que 87,09% de los alumnos obtuvieron apuntes iguales o superiores a la media necesaria para la aprobación. Esperamos que hayamos contribuído para mejorar la calidad de la enseñanaza de química y que este trabajo sea solamente un comienzo de una gran jornada

Uma abordagem histórica para o ensino do princípio da inércia

Placed in the field of Didactic of Science, this paper proposes an approach to the introduction of the History of Science in science education, at high school level. It was designed and implemented a series of activities regarding the history of the Principle of Inertia. The aim of this approach was to give more meaning to scientific education, while opening new avenues for a better understanding of the processes of construction of scientific knowledge. The preparation of the activities involved a study of the historical development of the concept of motion, from the Aristotelian physics through physical movement concepts at medieval period, from Galileo, Gassendi, Descartes, until the first law of Newton. The strategy of teaching was applied to three classes of high school (night period) of a state public school at the city of Natal (RN). The results indicated the difficulty of overcoming alternative conceptions about movement by students. Nevertheless, we consider that the implementation of this strategy of teaching both represented gains for the learning of students, and contributed to the resizing of pedagogical practices of the teacher-researcher

Opiniões de professores do ensino médio: refletindo sobre os projetos escolares e a interdisciplinaridade

Official documents indicate to a curriculum organization that promotes the dialogue in different areas of knowledge. Among the proposals strategies are the "School Projects". This research appears from the staff need evidenced in the development of practice of the researcher in recent years as Pedagogical Advisor in high school. The comments made in the daily work on the kinds of projects and how they were developed in the school, generated concerns. They aroused the interest in further the discussion, aiming to reflect with teachers about the implementation of a pedagogic action on the use of educational projects in the classroom, as a didactic strategy which promotes the learning of students. In this sense, it seeks to develop studies and discussions by the application of questionnaires and the holding of a workshop with teachers in the area of Science of Nature and Mathematics in private high school institutions from Natal, searching opinions of them as the preparation and development of school projects. As general purpose, it aims to contribute with elements to the reflection of the teachers on the use of this strategy of education. For both, we propose: the knowledge of ideas/opinions of teachers on planning, development and evaluation of projects, both disciplinary and interdisciplinary, identifying the main difficulties of these teachers about the work with projects at school; reviewing projects developed at school after the press conference in a meeting with teachers, incorporating the identified aspects as weak points. In the course of the methodology research, questionnaires were used with open and closed questions for the lifting of preliminary ideas for teachers in order to subsidize the planning of a developed meeting later in the school itself on the subject in question. 10 teachers took part of the first step and 17 in the second one (pressconference). In the third stage, an individual interview was carried out and analysis of projects already developed. It is observed that, as the main difficulty for the development of projects in school, pointed to the time factor in the planning team, followed by excessive working hours for teachers that, generally, also work in other schools. Some teachers say they do not develop projects for not having knowledge of how to develop school projects, neither disciplinary, nor interdisciplinary

Abordando as relações ctsa no ensino da química a partir das crenças e atitudes de licenciandos: uma experiência ormativa no Sertão Nordestino

Este estudio investigó las actitudes y creencias de los estudiantes universitarios en Ciencias Químicas por la Universidad de Río Grande do Norte (UERN) como un paso hacia la elaboración de una propuesta de material didáctico para el estudio de las relaciones CTSA en la licenciatura en química. Para el conocimiento de las actitudes y creencias fue utilizado dos instrumentos (Escala Likert y un cuestionario), que proporcionó un análisis dentro del nuevo paradigma de investigación (cuantitativa y cualitativa) en la Enseñanza de la Ciencia y Matemáticas. Los resultados mostraron que los estudiantes de licenciatura en química tienen creencias positivistas y que suelen son considerados por algunos como ingenuas, como la creencia en el modelo de decisión tecnocrática, la linealidad del desarrollo científico y tecnológico que lleva a el bienestar social y neutralidad de los conocimientos científicotecnológico. Basándose en estos datos y la literatura sobre el tema se elaboraron tres módulos de aprendizaje: a) Cuestionando la hegemonía del conocimiento técnico y científico, b) Las relaciones entre ciencia, tecnología, sociedad y medio ambiente - las relaciones CTSA c) Propuesta de temática para la enseñanza de la química en una perspectiva de CTSA: El Río Mossoró. Por último, el material producido se utilizó en dos cursos ocurridos en el Campus Central en el Centro de Educación Superior en São Miguel, ambos de UERN. Los participantes expresaron su aprobación al enfoque trajo de el experimento propuesto y de el caso de simulación contenidos en la propuesta de

Uma investigação histórica sobre os logaritmos com sugestões didáticas para a sala de aula

This study was conducted from a preliminary research to identify the conceptual and didactic approach to the logarithms given in the main textbooks adopted by the Mathematics teachers in state schools in the School of Natal, in Rio Grande do Norte. I carried out an historical investigation of the logarithms in order to reorient the math teacher to improve its educational approach this subject in the classroom. Based on the research approach I adopted a model of the log based on three concepts: the arithmetic, the geometric and algebraic-functional. The main objective of this work is to redirect the teacher for a broad and significant understanding of the content in order to overcome their difficulties in the classroom and thus realize an education that can reach the students learning. The investigative study indicated the possibility of addressing the logarithms in the classroom so transversalizante and interdisciplinary. In this regard, I point to some practical applications of this matter are fundamental in the study of natural phenomena as earthquakes, population growth, among others. These practical applications are connected, approximately, Basic Problematization Units (BPUs) to be used in the classroom. In closing, I offer some activities that helped teachers to understand and clarify the meaningful study of this topic in their teaching practice

Formação continuada de professores que ensinam matemática: o papel do ábaco na ressignificação da prática pedagógica

The present dissertation performs a study about abacus part on the continuous education of Elementary School s Mathematic teachers on what concerns the basic operations of addition and subtraction with (re)unification by using the manipulative and/or informatical abacus. Therefore, the research intends to answer the following question: How does a teacher reframe the pedagogical practice while teaching the Decimal Numeral System and the conventional operations of addition and subtraction with (re)unification through manipulative and informatical abacus? In order to do so, we rely ourselves on the Guy Brousseau s Theory of Didactic Situations (TDS) from 1996 that affirms the necessity to trace a way in accordance with the teaching situations that lead the student s learning; and on the work of Pierre Lévy (1993), in which the poles of communication oral, written and virtual create three ways of communication through which the learning process happens. The methodology of this paper was based on the Strategic Research-Action of Franco (2005). The didactic sequence was elaborated in accordance with TDS and used the manipulative and informatical abacus as didactic resource. With the application of the didactic sequence, it was verified that the continued formation of Elementary School s teachers concerning the operations of addition and subtraction on the initial years/levels is pertinent once it has been observed some difficulties of the teachers concerning this mathematical subject. Besides, the analysis of the didactic sequence has allowed one to realize that teachers had some difficulties concerning the numeric representation with order zero, the resolution of operations of addition and subtraction using the manipulative and informatical abacus and the realization of (re)unification on the subtraction with meaning. These observations has been discussed with the teachers and, after that, it has been done some didactic-methodological routings of the operations of addition and subtraction with re(unification) that contributes with the teaching and learning process.

O ensino por problemas nos livros de química: uma análise do conteúdo estrutura atômica

La enseñanza de problemas se ha investigado en la didáctica de las ciencias naturales como un medio importante para desarrollar el aprendizaje de los conocimientos científicos y la formación de competencias básicas. Dada la importancia de los libros de texto para la enseñanza de la ciencia, con el fin de verificar el enfoque de la enseñanza con problemas en los libros de química, se procedió a una investigación realizada en las obras aprobadas en PNLD 2012, basado en el método de Análisis de Contenido. Se analizó el contenido de la estructura atómica, como marco teórico la perspectiva de la enseñanza problémica, basada en el materialismo histórico y dialéctico. Metodológicamente la investigación presenta un carácter cualitativo. Los resultados del análisis de contenido corroboraron la cuestiones de estudio iniciales relacionadas con la explicación centrándose en los problemas, lo que permitió inferir la elaboración de una Unidad Didactica basada en los métodos problémicos para la enseñanza de los modelos atómicos por la exposición problémica, la conversación heurística y la busca parcial, como forma de aproximar los estudiantes a la naturaleza de las ciencias naturales y contribuir al desarrollo de actitudes positivas en el aprendizaje de la química

Uma proposta de ensino para o nível fundamental a partir das concepções sobre insetos

O presente trabalho consiste em uma investigação acerca das concepções de estudantes sobre o que é um inseto. Partiu-se do pressuposto de que os alunos expressam concepções errôneas no momento de identificar os representantes do táxon Insecta e que isso é consequência das experiências do cotidiano e de erros conceituais oriundos da formação escolar incorreta. Os objetivos deste trabalho foram investigar sobre concepções alternativas acerca dos insetos com alunos do ensino fundamental II e propor situações para promoção de uma aprendizagem mais ativa. Os dados para analise foram coletados em três turmas de escolas diferentes: uma escola em Nova Parnamirim, da rede privada, e duas da rede pública municipal de ensino: uma do município de Natal/RN e a outra do município de Parnamirim/RN. Utilizou-se como instrumento um questionário aplicado em duas fases. Na primeira etapa foram feitas três questões abertas e duas fechadas. Na segunda, aplicaram-se mais três questões. Nesta oportunidade foram apresentados aos alunos uma lista com imagens de insetos e animais considerados não insetos. Os resultados dos questionários mostraram que os alunos apresentaram na sua maioria, 62%, sentimentos negativos sobre os insetos, expressos por palavras depreciativas, entre elas: nojentos, feios, asquerosos, perigosos, sendo estes mais da metade dos alunos da amostra. Sentimentos positivos representaram 20%: fazem bem ao homem, Deus criou, são bons, são bonitos, e 18% apresentaram neutralidade nessas categorias. Outro resultado apresentado foi que 82% generalizaram os animais artrópodes como sendo insetos. Como forma de resolver problemas relacionados as concepções uma unidade didática foi aplicada em uma das escolas envolvidas na pesquisa, validando assim um instrumento pedagógico que incluiu atividade lúdica constituída de um jogo de tabuleiro proporcionador de uma vivência de aprendizagem focada em conceitos científicos sobre os insetos fáceis de serem apreendidos

Atividades estruturais de equações polinomiais numa abordagem histórica por meio de e-book

The present study investigates how the inter-relationship of the content of polynomial equations works with structured activities and with the history of mathematics through a sequence of activities presented in an e-book, so that the result of this research will proceed will result in a didactic and pedagogic proposal for the teaching of polynomial equations in a historical approach via the reported e-book. Therefore, we have considered in theoretical and methodological assumptions of the History of Mathematics, in structured activities and new technologies with an emphasis on e-book tool. We used as a methodological approach the qualitative research, as our research object adjusts to the objectives of this research mode. As methodological instruments, we used the e-book as a synthesis tool of the sequence of activities to be evaluated, while the questionnaires, semi-structured interviews and participant observation were designed to register and analyze the evaluation made by the research, participants in the structured activities. The processing and analysis of data collected though the questionnaires were organized, classified and quantified in summary tables to facilitate visualization, interpretation, understanding, and analysis of these data. As for participant observation was used to contribute to the qualitative analysis of the quantified data. The interviews were synthetically transcribed and qualitatively analyzed. The analysis ratified our research objectives and contributed to improve, approve and indicate the use of e-book for the teaching of polynomial equations. Thus, we consider that this educational product will bring significant contributions to the teaching of mathematical content, in Basic Education

Física do meio ambiente: desafios de uma disciplina focada na formação de habilidades gerais

A disciplina Física do Meio Ambiente (FMA) foi criada em 1976 no Departamento de Física Teórica e Experimental da UFRN e, atualmente, faz parte da estrutura curricular do curso de Licenciatura em Física da UFRN e é de caráter obrigatório. Tal caráter se justifica, dentre outros motivos, pelo fato de que esta disciplina representa uma boa oportunidade dos licenciandos estudarem de que forma a Física pode contribuir para a compreensão de fenômenos relativos ao nosso Meio Ambiente, sejam eles relacionados às atividades humanas ou aos fenômenos naturais propriamente ditos e que, de uma forma ou de outra, afeta a sociedade. O nosso trabalho de pesquisa teve como objetivo principal elaborar um novo programa de ensino para a disciplina de Física do Meio Ambiente adequado às necessidades da educação científica para o século XXI. A pesquisa foi conduzida inicialmente com um levantamento histórico da disciplina desde sua origem no Departamento de Física ate os dias atuais, analise dos Projetos Pedagógicos do curso de Licenciatura em Física da UFRN, revisão bibliográfica sobre as definições de competências e habilidades em um contexto de ensino e segundo o pensamento de vanguarda nesse campo de pesquisa, acompanhamento do curso durante um semestre através de aulas observacionais, aplicação de questionário para a coleta de dados e análise de alguns livros didáticos de Física do Ensino Médio. A partir do perfil ou modelo profissional para o licenciado em Física da UFRN definimos os objetivos gerais para a disciplina de FMA em termos de habilidades gerais relacionadas com as atividades que um futuro professor de Física irá desempenhar no seu dia a dia. O nosso programa de ensino foi pensado no sentido de introduzir conteúdos de didática específica ao longo da disciplina, isto é, familiarizar os professores em formação com investigação e inovação didáticas voltadas para o ensino de temas que envolvam a conexão entre Física e Meio Ambiente. Como resultado de nossa pesquisa foi proposto um novo Programa de Ensino para FMA que pode ser útil aos futuros professores desta disciplina e foi elaborado segundo uma metodologia de organização científica do processo ensino