Modelagem e controle de um microveículo aéreo: uma aplicação de estabilidade robusta com a técnica backstepping em uma estrutura hexarrotor

In this Thesis, the development of the dynamic model of multirotor unmanned aerial vehicle with vertical takeoff and landing characteristics, considering input nonlinearities and a full state robust backstepping controller are presented. The dynamic model is expressed using the Newton-Euler laws, aiming to obtain a better mathematical representation of the mechanical system for system analysis and control design, not only when it is hovering, but also when it is taking-off, or landing, or flying to perform a task. The input nonlinearities are the deadzone and saturation, where the gravitational effect and the inherent physical constrains of the rotors are related and addressed. The experimental multirotor aerial vehicle is equipped with an inertial measurement unit and a sonar sensor, which appropriately provides measurements of attitude and altitude. A real-time attitude estimation scheme based on the extended Kalman filter using quaternions was developed. Then, for robustness analysis, sensors were modeled as the ideal value with addition of an unknown bias and unknown white noise. The bounded robust attitude/altitude controller were derived based on globally uniformly practically asymptotically stable for real systems, that remains globally uniformly asymptotically stable if and only if their solutions are globally uniformly bounded, dealing with convergence and stability into a ball of the state space with non-null radius, under some assumptions. The Lyapunov analysis technique was used to prove the stability of the closed-loop system, compute bounds on control gains and guaranteeing desired bounds on attitude dynamics tracking errors in the presence of measurement disturbances. The controller laws were tested in numerical simulations and in an experimental hexarotor, developed at the UFRN Robotics Laboratory

Modelagem e medições de ondas de rádio para predição de perda de propagação em ambientes urbanos

In this dissertation new models of propagation path loss predictions are proposed by from techniques of optimization recent and measures of power levels for the urban and suburban areas of Natal, city of Brazilian northeast. These new proposed models are: (i) a statistical model that was implemented based in the addition of second-order statistics for the power and the altimetry of the relief in model of linear losses; (ii) a artificial neural networks model used the training of the algorithm backpropagation, in order to get the equation of propagation losses; (iii) a model based on the technique of the random walker, that considers the random of the absorption and the chaos of the environment and than its unknown parameters for the equation of propagation losses are determined through of a neural network. The digitalization of the relief for the urban and suburban areas of Natal were carried through of the development of specific computational programs and had been used available maps in the Statistics and Geography Brazilian Institute. The validations of the proposed propagation models had been carried through comparisons with measures and propagation classic models, and numerical good agreements were observed. These new considered models could be applied to any urban and suburban scenes with characteristic similar architectural to the city of Natal

Utilização de redes neurais artificiais para detecção e diagnóstico de falhas

In a real process, all used resources, whether physical or developed in software, are subject to interruptions or operational commitments. However, in situations in which operate critical systems, any kind of problem may bring big consequences. Knowing this, this paper aims to develop a system capable to detect the presence and indicate the types of failures that may occur in a process. For implementing and testing the proposed methodology, a coupled tank system was used as a study model case. The system should be developed to generate a set of signals that notify the process operator and that may be post-processed, enabling changes in control strategy or control parameters. Due to the damage risks involved with sensors, actuators and amplifiers of the real plant, the data set of the faults will be computationally generated and the results collected from numerical simulations of the process model. The system will be composed by structures with Artificial Neural Networks, trained in offline mode using Matlab®

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

Aprendendo e ensinando o sistema de numeração decimal: uma contribuição à prática pedagógica do professor

The central question of the present study is to identify the epistemological knowledge that the teachers-trainees possess regarding the characteristics (properties) of the decimal numbering system; its purpose is to offer a contribution to the pedagogic practice of the teachers who work within the Basic Literacy Cycle, in terms of what concerns both the acquisition of contents and the development of the knowledge that helps them in the elaboration of adequate strategies to working with the Decimal Numbering System in the classroom. The study is based on the constructivist sociointeractionist approach to teaching Mathematics and it constitutes, in itself, a methodological intervention with the teachers-trainees engaged in the Professional Qualification Program in Basic Education of the Federal University of Rio Grande do Norte. The foundations of the study were found in investigations of researchers who had carried out studies on the construction of numerical writing, showing, for instance, that the construction process of ideas and procedures involved in groupings and changes to base 10 take a lot longer to be accomplished than one can imagine. A set of activities was then elaborated which could not only contribute to the acquisition of contents but that could also make the teachers-trainees reflect upon their teaching practices in the classroom so that in this way they will be able to elaborate more consistent didactic approaches, taking into consideration the previous knowledge of the students and also some obstacles that often appear along the way. Even when teachers have access to the most appropriate dicactic resources, the lack of knowledge of the content and of the real meaning of that content make the Decimal Numbering System, a subject of fundamental importance, be taught most times in a mechanical way. The analisys of the discussions and behaviours of the teachers-trainees during the activities reavealed that they made them reflect upon their current practices in the classroom and that, as a whole, the aims of each of the activities carried out with the teachers-trainers were reached

A leitura e o leitor presumido nas avaliações oficiais

Este estudio se refiere a una investigación a cerca de la concepción de la lectura que subyace en la Matriz de Referencia de la Prueba Brasil, y, mediante las análisis del modelo 2009, entender lo que el lector se supone que responder en las preguntas de esta prueba. El estudio tiene como objetivo satisfacer se presume lector general para responder a las preguntas de prueba de Brasil y el mapa de la concepción de la lectura que subyace en la matriz de referencia tal prueba. Los objetivos específicos apuntan a examinar los temas de Prueba Brasil, identificando qué descriptores se materializan en el mismo, que son los más recurrentes. El estudio tiene como fundamentos los estudios bakhtinianos a cerca de los diálogos del linguaje (Bakhtin, 2003, 2008; Volochínov/Bakhtin, 1993) y la concepción de la lectura defendida por Geraldi (2007), Larossa (2001) y DeCerteau (1994). La investigación és caracterizada como cualitativo-interpretativo, con enfoque socio-histórico, y se encuentra dentro del campo de la Lingüística Aplicada, que en las últimas décadas ha demostrado contribuciones para la enseñanza de lenguas y formación docente. Para hacer el análisis de las pruebas, inicialmente construido una tabla (Tabla 1), que contiene los seis macrotópicos Matrix lengua portuguesa en la que estábamos repartiendo los descriptores presentes en las cuestiones de prueba referenciada relacionándolos con sus temas. Tras analizar la cuestión, con el fin de identificar al presunto lector a responder a estas preguntas. Mediante análisis de la Matriz de Referencia de la Prueba Brasil, entendemos que ella está de acuerdo con los Parámetros Curriculares de la Lengua Portuguesa. Así, la concepción que subyace en la lectura es que la lectura es una actividad que depende del proceso individual, pero que és parte de un contexto social e involucra a habilidades relacionadas con la comprensión y producción de sentido. Mediante la observación de la prueba, afirmamos qué el lector con la capacidad de responder a las preguntas es lo que desarrolla actitudes favorables a cerda de la lectura. A saber: (i) reconocen ampliamente las palabras, (ii) identifican los objetivos y funciones de la lectura, en reconocimiento de la función de apoyo de género y el contexto del texto, (iii) predice el contenido de los textos a se lee a la luz de su apoyo, su género y su contexto; (iv) plantea hipótesis sobre el contenido del texto que se lee, (v) es capaz de buscar ideas textual e intertextual. Es decir, hace inferencias, aumentando la comprensión, la asociación de diversos elementos presentes en el texto y que son parte de sus propias experiências personales, (vi) construye la comprensión global del texto leído por la unificación de la información explícita e implícita, (vii) tiene la capacidad de evaluar la lectura de forma ética y afectiva, o de hacer extrapolaciones coerentes sin escapar de la temática del texto. Por último, podemos decir que las implicaciones pedagógicas de este trabajo para mi actividad profesional es de gran importancia, ya que desde la detección de lo que se requiere de los estudiantes y, en consecuencia, un nuevo enfoque para la enseñanza de la lengua materna como podemos reflexionar sobre eso y encontrar maneras de mejorar nuestro desempeño. Tanto nuestro entrenador como nuestros compañeros. Dejando a un nivel puramente descriptivo de los problemas de acción conjunta más eficaz, entendiendo que la enseñanza de lectura tiene un carácter complejo. En este sentido, tenemos que ser menos intuitivo y más reflexiva. Nos gustaría hacer hincapié en que tenemos la intención de socializar esta investigación con nuestros compañeros, ya que entendemos que es un material que puede contribuir a un nuevo aprendizaje para la práctica de los profesores que se inclinan. Además indicó que la principal contribución de este trabajo es nuestra mirada en el proceso de la lectura en el aula, la comprensión de que el estudiante de ofertas diarias con textos localizados, derechos de autor, histórico y representativo de las diferentes interacciones en el mundo. Por lo tanto, es el momento de ser gestado las prácticas de lectura hacia una educación más significativa

Fundamentos da filosofia moral de Peter Singer

This research aims to reconstruct and explain the argument proposed by Peter Singer to justify the principle of equal consideration of interests (PECI). The PECI is the basic normative principle according to people should consider the interests of all sentient beings affected when somebody taking a moral decision. It is the join that Singer proposes between universalizability and the principle of equal consideration of interests that constitutes a compelling reason to justify it. The universalizability requires to disregard the numerical differences, putting yourself in other people s shoes, and to consider preferences, interests, desires and ideals of those affected. Singer joins universalizability to normative principle and molds the form and content of his theory. The first chapter introduces the discussion will be developed in this essay. The second chapter deals the historical and philosophical viewpoint from which Singer starts his studies. The third chapter is about the Singer s critiques of naturalism, intuitionism, relativism, simple subjectivism and emotivism. The fourth chapter exposes the design of universal prescriptivism proposed by R. M. Hare. The universal prescriptivism indicates, in the Singer s viewpoint, a consistent way to create the join between the universalizability and PECI. It highlights also the criticism designed by J. L. Mackie and Singer himself to universal prescriptivism. The second part of this chapter shows briefly some of the main points of the classical conception of utilitarianism and its possible relationship with the theory of Singer. The fifth chapter introduces the Singer s thesis about the origin of ethics and the universalizability as a feature necessary to the point of view of ethic, and the way which this argument is developed to form the PECI. The sixth chapter exposes the main distinctions that characterize the PECI. Finally the seventh chapter provides a discussion about the reasons highlighted by Singer for one who wants orient his life according to the standpoint of ethics. This structure allows explaining the main ideas of the author concerning the theoretical foundations of his moral philosophy

Algoritmos genéticos canônico e elitista: uma abordagem comparativa

Universidade Federal do Rio Grande do Norte

A inclusão escolar da subjetividade do professor à constituição de um lugar de aluno

The move to include students with special needs (NEE) in the schools presents a paradigm that raises continual discussion about how to implement this proposal. Considering that learning is built from the weaving of socially constructed knowledge and the field of knowledge concerning subjectivity, this research explores the difficulties that occur with the later in the process of inclusion in the schools. Admittedly, the promise implicit in the school does not guarantee that the student learn, but the envisioning of this learning, when the student s educator discredits him, is such that the person is then not taken on as an actual student, being excluded from the transmission of knowledge, even within the school. The project implemented at the Instituto Educacional Casa Escola IECE, for the last three years, shows us that the possibility and sustainability of this envisioning is intimately linked to the subjectivity of the educator, as well as how one relates to the institutional culture. We question then, how this perspective is formed in the educator this perspective capable of denying the offer of a place as student, allowing him to advance while learning. With this in mind, we explore the paradoxical elements present in the paradigm of inclusion, as well as analyzing theoretically, through the body of conceptual psychoanalysis, the process of subjective constitution. We intend to bring to light how this process coincides with the construction of the educator s perspective of exemption from teaching the special needs students. We question, through the formative functions of subjective structuring (The Mirror Stage and the Oedipus Complex), how to form a perspective capable of promoting inclusion of special needs students in educators. Finally, we show how it is possible to bring to light, with the concepts of the I ideal and the ideal I, the subjective difficulties in the practicing instructor

Java-XSC : módulo complexo e complexo intervalar

This work aims to develop modules that will increase the computational power of the Java-XSC library, and XSC an acronym for "Language Extensions for Scientific Computation . This library is actually an extension of the Java programming language that has standard functions and routines elementary mathematics useful interval. in this study two modules were added to the library, namely, the modulus of complex numbers and complex numbers of module interval which together with the modules original numerical applications that are designed to allow, for example in the engineering field, can be used in devices running Java programs

Saberes docentes, alfabetização, respeito à infância: a criança de 6 anos no ensino fundamental

Éste trabajo se inserta en el ámbito de los cambios en la Enseñanza Fundamental (EF) brasileño que, por la Ley Federal n.º 11.114/2005 anticipa el EF para seis años de edad, y de la Ley n.º 11.274/2006 que amplia el mismo nivel de enseñanza de ocho para nueve años Tales cambios tienen sido respaldados por el argumento de la importancia de se anticipar y promover un mayor acceso a la educación y garantizar una permanencia bien sucedida del alumno en la etapa obligatoria de la Educación Básica. La inclusión de los niños de seis años en el EF puede ser considerada una conquista en el ámbito de las políticas públicas brasileñas destinadas a la educación de niños. Sin embargo, la sencilla simples anticipación/ampliación de matrículas en el EF puede constituirse en más una forma de exclusión, si no fueren garantizadas las condiciones necesarias para se ofrecer una educación de calidad que considere las peculiaridades de una práctica pedagógica de alfabetización con niños más jóvenes. Evidentemente, muchos son los factores que pueden influenciar la calidad de la educación y el tratamiento escolar financiamiento, gestión, organización del espacio escolar pero la acción del profesor, en ése sentido, es un factor primordial entre otros determinantes. Así pensando, definimos como objetivo de éste trabajo investigar saberes docentes requeridos de el profesor para el desarollo de una práctica pedagógica que tiene por meta la apropiación de la lengua escrita, por el niño de seis años recién-ingresa en la Enseñanza Fundamental respetando su condición de ser niño . Para tanto, en el ámbito del enfoque cualitativo de la encusta, realizamos un estudio de caso en dos instituciones públicas: Escola Municipal Professora Emilia Ramos y Centro Municipal de Educação Infantil Marise Paiva, ambas ubicadas en la Zona Este en la ciudad de Natal. De la análisis del contenido de los datos, emergió la temática Saberes Docentes para la Alfabetización de Niños de seis años en la Enseñanza Fundamental que, a la vez, cubre dos categorías de saberes, con suyas respectivas subcategorías: Saberes Docentes Transversales a las Práctica Pedagógica de Alfabetización y Saberes Docentes Específicos a la Práctica Pedagógica de Alfabetización. Entre tantos aprendizaje proporcionadas por el estudio, comprendemos que, sea en la Educação Infantil, sea en la Enseñanza Fundamental, el trabajo con el niño no debe constituirse en la negación de su infancia. Sin embargo, en se tratando de el EF, el esfuerzo para no desvirtuar la voluntad política de proporcionar al niño oportunidades de alfabetización debe ser redoblado, una vez que ésa etapa de la educación podrá ser la marca de un rico y agradable proceso de alfabetización, como puede ser motivo para que el niño se torne desinteresado y acobardado para aprender a leer y a escribir, si no fueren respetadas las necesidades y especificidades propias de ése momento de su desarollo. El estudio también ratificó nuestra comprensión de que la Alfabetización es un proceso peculiar, no constituyéndose, por lo tanto, en tarea simple para el docente, ni tampoco para el niño, visto que la lengua escrita, por si misma, ya es un objeto de estudio bastante complejo. Comprendemos, sin embargo, que esa complejidad no puede tornarse obstáculo para que, también en la escuela pública, ya a los seis años, se permita al niño un trabajo de calidad que tiene por meta su alfabetización, hasta porque, mientras participantes de una sociedad letrada, antes de ingresar a la escuela, los niños ya construyeran concepciones previas sobre la lectura y la escrita, a las cuales el profesor debe estar muy atento

Efeitos de Confinamento de Vórtice Magnético em Nanodiscos de Fe e Py

We report two theoretical works, based in numerical simulations. The first study consists in the investigation of equilibrium phases and vortex formation in Ferro and Permalloy circular and square nanoelements.The another have the aim to investigate the magnetostatic interaction between pairs of nanodisks of Ferro and Permalloy and it`s impact in the vortex structure

Modelagem Matemática e Computacional de fenômenos eletrocinéticos em meios porosos carregados eletricamente

In this work we present a mathematical and computational modeling of electrokinetic phenomena in electrically charged porous medium. We consider the porous medium composed of three different scales (nanoscopic, microscopic and macroscopic). On the microscopic scale the domain is composed by a porous matrix and a solid phase. The pores are filled with an aqueous phase consisting of ionic solutes fully diluted, and the solid matrix consists of electrically charged particles. Initially we present the mathematical model that governs the electrical double layer in order to quantify the electric potential, electric charge density, ion adsorption and chemical adsorption in nanoscopic scale. Then, we derive the microscopic model, where the adsorption of ions due to the electric double layer and the reactions of protonation/ deprotanaç~ao and zeta potential obtained in modeling nanoscopic arise in microscopic scale through interface conditions in the problem of Stokes and Nerst-Planck equations respectively governing the movement of the aqueous solution and transport of ions. We developed the process of upscaling the problem nano/microscopic using the homogenization technique of periodic structures by deducing the macroscopic model with their respectives cell problems for effective parameters of the macroscopic equations. Considering a clayey porous medium consisting of kaolinite clay plates distributed parallel, we rewrite the macroscopic model in a one-dimensional version. Finally, using a sequential algorithm, we discretize the macroscopic model via the finite element method, along with the interactive method of Picard for the nonlinear terms. Numerical simulations on transient regime with variable pH in one-dimensional case are obtained, aiming computational modeling of the electroremediation process of clay soils contaminated