Uma reavaliação do pensamento lógico de George Boole à luz da história da matemática

The aim of the present study is to reevaluate the logical thought of the English mathematician George Boole (1815 - 1864). Thus, our research centers on the mathematical analysis of logic in the context of the history of mathematics. In order to do so, we present various biographical considerations about Boole in the light of events that happened in the 19th century and their consequences for mathematical production. We briefly describe Boole's innovations in the areas of differential equations and invariant theory and undertake an analysis of Boole's logic, especially as formulated in the book The Mathematical Analysis of Logic, comparing it not only with the traditional Aristotelian logic, but also with modern symbolic logic. We conclude that Boole, as he intended, expanded logic both in terms of its content and also in terms of its methods and formal elaboration. We further conclude that his purpose was the mathematical modeling of deductive reasoning, which led him to present an innovative formalism for logic and, because the different ways it can be interpreted, a new conception of mathematics

Educação ambiental: mediações sociais e políticas e a indolência do Poder Público à sua inclusão no ensino formal

As a result of the prediction of irreversible changes on necessary conditions to maintain life, including human, on the planet, environmental education got the spotlight in the political scenario, due to social pressure for the development of individual and collective values, knowledge, skills, attitudes and competences towards environmental preservation. In Brazil, only in 1999 the right for environmental education was officially granted to people, having the status of essential and permanent component in the country s education. Since then, it has been Government s duty, in each federal branch, to plan actions to make it happen, in an articulate way in all levels and modalities of the education process, both formally and informally. This work of research has environmental education in the school as subject matter, and aims on analyzing social and political mediations established between this National Environmental Education policy and the contexts associated to the legislative production process, the political nature of the conceptions about environmental education that underlie Law 9.795/99 (Brazil, 2009c) and also Rio Grande do Norte Government s actions and omissions related to the imperative nature of the insertion of environmental education in the schools ran by the state, during the ten years this law has been in force. The investigation of the subject matter was led by a social and historical understanding of the social and environmental phenomena, as well as of the education system as a whole, considering that only through a dialectical view we can see the real world, by destroying the pseudo-concreteness that surrounds the topic. While analyzing, we assumed that in face of the dominance of a social organization in which market regulations rule on environmental ones, by developing individual and collective critical conscience, environmental education can become a threat to dominant economical interests in exploiting natural resources. The results of this research suggest that as an educational practice to be developed in an integrated, continuous and permanent fashion in all levels and modalities of formal education, environmental education has not yet come to pass in the state of Rio Grande do Norte, due to the neglect and disrespect of the government when facing the need of promoting the necessary and legally appointed measures to make it present in the basic education provided by the state. The legislators silence when it comes to approving a regulation on environmental education essential to define policies, rules and criteria to teaching the subject in the state and the omission from the public administration regarding critical actions in order to integrate in public schools the activities related to the National Environmental Education Policy, represent a political decision for not doing anything, despite the legal demand for an active position. This neglecting attitude for the actualizing of strategically concrete actions, urgent and properly planned for the implementation of environmental education in schools in a multidisciplinary way, exposes the lack of interest the predominant classes have in such kind of education being made available, as it could be developed based on a critic political view, becoming a political and educational action against dominance. When analyzing the basic principles and fundamental goals in Law 9.795/99 (Brazil, 2009c) the development of a critic environmental education is really possible and concurs with the National Environmental Education Policy, reflecting the social and political mediations established between this public policy and the contexts associated to its legislative production process, which are responsible for approving a regulation which also represents the mind of the people about environmental protection above anything else

Avaliação de um programa de educação ambiental não formal: a Caravana Ecológica na visão dos participantes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Algoritmos genéticos: uso de lógica nebulosa e análise de convergência por cadeia de Markov

In this work, the Markov chain will be the tool used in the modeling and analysis of convergence of the genetic algorithm, both the standard version as for the other versions that allows the genetic algorithm. In addition, we intend to compare the performance of the standard version with the fuzzy version, believing that this version gives the genetic algorithm a great ability to find a global optimum, own the global optimization algorithms. The choice of this algorithm is due to the fact that it has become, over the past thirty yares, one of the more importan tool used to find a solution of de optimization problem. This choice is due to its effectiveness in finding a good quality solution to the problem, considering that the knowledge of a good quality solution becomes acceptable given that there may not be another algorithm able to get the optimal solution for many of these problems. However, this algorithm can be set, taking into account, that it is not only dependent on how the problem is represented as but also some of the operators are defined, to the standard version of this, when the parameters are kept fixed, to their versions with variables parameters. Therefore to achieve good performance with the aforementioned algorithm is necessary that it has an adequate criterion in the choice of its parameters, especially the rate of mutation and crossover rate or even the size of the population. It is important to remember that those implementations in which parameters are kept fixed throughout the execution, the modeling algorithm by Markov chain results in a homogeneous chain and when it allows the variation of parameters during the execution, the Markov chain that models becomes be non - homogeneous. Therefore, in an attempt to improve the algorithm performance, few studies have tried to make the setting of the parameters through strategies that capture the intrinsic characteristics of the problem. These characteristics are extracted from the present state of execution, in order to identify and preserve a pattern related to a solution of good quality and at the same time that standard discarding of low quality. Strategies for feature extraction can either use precise techniques as fuzzy techniques, in the latter case being made through a fuzzy controller. A Markov chain is used for modeling and convergence analysis of the algorithm, both in its standard version as for the other. In order to evaluate the performance of a non-homogeneous algorithm tests will be applied to compare the standard fuzzy algorithm with the genetic algorithm, and the rate of change adjusted by a fuzzy controller. To do so, pick up optimization problems whose number of solutions varies exponentially with the number of variables

Automação da detecção de fraudes em sistemas de medição de energia elétrica utilizando lógica fuzzy em ambiente SCADA

This works presents a proposal to make automatic the identification of energy thefts in the meter systems through Fuzzy Logic and supervisory like SCADA. The solution we find by to collect datas from meters at customers units: voltage, current, power demand, angles conditions of phasors diagrams of voltages and currents, and taking these datas by fuzzy logic with expert knowledge into a fuzzy system. The parameters collected are computed by fuzzy logic, in engineering alghorithm, and the output shows to user if the customer researched may be consuming electrical energy without to pay for it, and these feedbacks have its own membership grades. The value of this solution is a need for reduce the losses that already sets more than twenty per cent. In such a way that it is an expert system that looks for decision make with assertivity, and it looks forward to find which problems there are on site and then it wont happen problems of relationship among the utility and the customer unit. The database of an electrical company was utilized and the datas from it were worked by the fuzzy proposal and algorithm developed and the result was confirmed

Lógica Fuzzy para Controle de pH em um Processo Petrolífero

This work proposes the design, the performance evaluation and a methodology for tuning the initial MFs parameters of output of a function based Takagi-Sugeno-Kang Fuzzy-PI controller to neutralize the pH in a stirred-tank reactor. The controller is designed to perform pH neutralization of industrial plants, mainly in units found in oil refineries where it is strongly required to mitigate uncertainties and nonlinearities. In addition, it adjusts the changes in pH regulating process, avoiding or reducing the need for retuning to maintain the desired performance. Based on the Hammerstein model, the system emulates a real plant that fits the changes in pH neutralization process of avoiding or reducing the need to retune. The controller performance is evaluated by overshoots, stabilization times, indices Integral of the Absolute Error (IAE) and Integral of the Absolute Value of the Error-weighted Time (ITAE), and using a metric developed by that takes into account both the error information and the control signal. The Fuzzy-PI controller is compared with PI and gain schedule PI controllers previously used in the testing plant, whose results can be found in the literature.

Sistema automatizado para o aproveitamento de água cinza e azul, com controle de PH utilizando lógica fuzzy

Every day, water scarcity becomes a more serious problem and, directly affects global society. Studies are directed in order to raise awareness of the rational use of this natural asset that is essential to our survival. Only 0.007% of the water available in the world have easy access and can be consumed by humans, it can be found in rivers, lakes, etc... To better take advantage of the water used in homes and small businesses, reuse projects are often implemented, resulting in savings for customers of water utilities. The reuse projects involve several areas of engineering, like Environmental, Chemical, Electrical and Computer Engineering. The last two are responsible for the control of the process, which aims to make gray water (soapy water), and clear blue water (rain water), ideal for consumption, or for use in watering gardens, flushing, among others applications. Water has several features that should be taken into consideration when it comes to working its reuse. Some of the features are, turbidity, temperature, electrical conductivity and, pH. In this document there is a proposal to control the pH (potential Hydrogen) through a microcontroller, using the fuzzy logic as strategy of control. The controller was developed in the fuzzy toolbox of Matlab®

Sistema para detecção e diagnóstico de falhas em motores elétricos de indução utilizando lógica fuzzy

Induction motors are one of the most important equipment of modern industry. However, in many situations, are subject to inadequate conditions as high temperatures and pressures, load variations and constant vibrations, for example. Such conditions, leaving them more susceptible to failures, either external or internal in nature, unwanted in the industrial process. In this context, predictive maintenance plays an important role, where the detection and diagnosis of faults in a timely manner enables the increase of time of the engine and the possibiity of reducing costs, caused mainly by stopping the production and corrective maintenance the motor itself. In this juncture, this work proposes the design of a system that is able to detect and diagnose faults in induction motors, from the collection of electrical line voltage and current, and also the measurement of engine speed. This information will use as input to a fuzzy inference system based on rules that find and classify a failure from the variation of thess quantities

Uma arquitetura baseada em SCTP e SIP para suporte a aplicações VoIP móveis e a especificação formal do seu módulo de controle

New versions of SCTP protocol allow the implementation of handover procedures in the transport layer, as well as the supply of a partially reliable communication service. A communication architecture is proposed herein, integrating SCTP with the session initiation protocol, SIP, besides additional protocols. This architecture is intended to handle voice applications over IP networks with mobility requirements. User localization procedures are specified in the application layer as well, using SIP, as an alternative mean to the mechanisms used by traditional protocols, that support mobility in the network layer. The SDL formal specification language is used to specify the operation of a control module, which coordinates the operation of the system component protocols. This formal specification is intended to prevent ambiguities and inconsistencies in the definition of this module, assisting in the correct implementation of the elements of this architecture

Controle de Temperatura do Sistema de Refrigeração a água de uma tocha plasmática Indutiva Utilizando Lógica fuzzy

Este projeto propõe desenvolver e implementar um controlador para o sistema de refrigeração da tocha indutiva a plasma térmico. Este processo é feito a partir da medição da temperatura através de um sensor do sistema de refrigeração. O sinal produzido será enviado para uma entrada analógica do microcontrolador da família PIC, que utilizando os conceitos de lógica fuzzy, controla a velocidade de um motor bomba. Este é responsável por diminuir ou aumentar o fluxo circulante de água que passa pela bobina, pelo corpo da tocha e pelo flange de fixação, deixando-os na temperatura desejada. A velocidade desta bomba será controlada por um inversor de frequência. O microcontrolador, também, acionará um ventilador caso exceda a temperatura de referência. A proposta inicial foi o desenvolvimento do controle da temperatura da bobina de uma tocha indutiva a plasma, mas com algumas adequações, foi possível também aplicar no corpo da tocha. Essa tocha será utilizada em uma planta de tratamento de resíduos industriais e efluentes petroquímicos. O controle proposto visa garantir as condições físicas necessárias para tocha de plasma, mantendo a temperatura da água em um determinado nível que permita o resfriamento sem comprometer, no entanto, o rendimento do sistema. No projeto será utilizada uma tocha de plasma com acoplamento indutivo (ICPT), por ter a vantagem de não possuir eletrodos metálicos internos sendo erodidos pelo jato de plasma, evitando uma possível contaminação, e também devido à possibilidade do reaproveitamento energético através da cogeração de energia. O desenvolvimento da tecnologia a plasma na indústria de tratamento de resíduos vem obtendo bons resultados. Aplicações com essa tecnologia têm se tornado cada vez mais importantes por reduzir, em muitos casos, a produção de resíduos e o consumo de energia em vários processos industriais

Utilização da lógica difusa no controle inteligente de sistemas eletro-hidráulicos

Electro-hydraulic servo-systems are widely employed in industrial applications such as robotic manipulators, active suspensions, precision machine tools and aerospace systems. They provide many advantages over electric motors, including high force to weight ratio, fast response time and compact size. However, precise control of electro-hydraulic systems, due to their inherent nonlinear characteristics, cannot be easily obtained with conventional linear controllers. Most flow control valves can also exhibit some hard nonlinearities such as deadzone due to valve spool overlap on the passage´s orifice of the fluid. This work describes the development of a nonlinear controller based on the feedback linearization method and including a fuzzy compensation scheme for an electro-hydraulic actuated system with unknown dead-band. Numerical results are presented in order to demonstrate the control system performance

A utilização de espaços de educação não formal por professores de biologia de Natal-RN

La práctica educativa en espacios no formales es un recurso didáctico catalizador de motivación e interese, tanto para alumnos como para los profesores. El crecimiento de los espacios no formales coincide con los cambios recientes en el mundo en los campos sociales, políticos, económicos y culturales. Como una de las consecuencias de esos cambios, tenemos el crecimiento de otras instancias difusoras de conocimientos rompiendo, así, la hegemonía de la escuela. De esa forma, en este trabajo busqué investigar la frecuencia y las formas de utilización de los espacios de educación no formal por profesores de biología, de la enseñanza media, de la Ciudad de Natal (RN). Procuré también, identificar cuales son los espacios de educación no-formal que son utilizados; describir los recursos y las acciones desarrolladas en eses espacios; identificar la existencia o no de interese y la importancia que atribuyen a los espacios para la enseñanza de biología, además de divulgar los espacios utilizados como recursos didácticos. Para alcanzar estos objetivos fueron hechas observaciones de los espacios, aplicados cuestionarios y realizadas entrevistas con los profesores que realizan actividades junto a tales instituciones. Para el análisis de los datos se utilizó tanto el abordaje cuantitativo como cualitativa. Nos basamos en referenciales teóricos de autores que buscan establecer las relaciones entre diferentes modalidades de educación para mejor comprender lo que es la educación no-formal y su trayectoria histórica. Constaté que los profesores utilizan los espacios de educación no-formales, aun la cantidad de visitas al año sea reducida, en virtud de varias dificultades por ellos apuntadas, tales como el transporte, la falta de recursos financieros y de apoyo para viabilizar la visita, entre otros. Verifiqué también que los profesores demostraron un alto interese por los espacios no-formales y apuntaron como principales justificativas para considerarlos importantes para la enseñanza de la biología la posibilidad de establecer conexiones entre la teoría y la practica, además de la complementariedad

A doença de criar passarinhos: a lírica humanizadora de João Cabral de Melo Neto

João Cabral de Melo Neto n a jamais aimé les vers sentimentaux et prolixes venus de la tradition romantique. C est pour ça que son uvre a un discours objectif, rigoureusement elaboré e elle comporte certaines influences concretistes ça explique pourquoi l auteur est connu comme l ingénieur de la langage. En verité, le poète même dissait qu il était un homme froid et rationnel. La critique a assidument analysé la matière logique et le rigeuer formel de l uvre de Cabral de Melo. Pourtant, dans ce travail nous analysons les poèmes dont le sentiments humaines sont la mtière principal de l élaboration de l experiènce esthétique. La poèsie de João Cabral n est pas simple verbalisme formel, ni un uvre sens vie, car les objects concrètes et la langage objectif n empêchent pas qui le sujet décrit avec émotion les scènes presents dans les poèmes. Nous travaillons avec la hypothèse de que le poète a une attitude trop humaine quand il parle de l experience culturel et de l experience de la vie dans le Nord-est brésilien. Les unités témathiques de ce travail, pourtant, montrent la représentation du Nord-est dans la poèsie de João Cabral et examinent aussi le sentiment qu il sent par la memoire culturel de sa région. Parmi les aspects qui composent sa lyrique humaine nous citons la personification constant de les paysages du Nord-est le poète ne veux pas faire une décrition tophographique de la région parce que les places ont un valeuer sentimentel pour lui; au moyen d un discours erotique, Cabral represente les desirs et les intints humaines de sa terre; ensuite, il semble que le poète est enchanté et enveloppé avec certains elemets culturels de sa région, come l hamac, la littérature oral et la musique régional; la preoccupation avec la population explorée et la denonciation de la condition miserable dans le Nord-est brésilien confirment aussi la humanité présent dans son uvre; finalment, la récordation de l enfance et la nostalgie du temps passé sont, pour le poète, un possibilité qui peut aider dans la formation humaine de la population

Lógica condicional

The main goal of this work is to clarify the central concepts involved in the study of formalization of conditional sentences. More specifically, it has been done a comparative analysis of the two greater and more traditional proposals of conditional formalization (Lewis 1973c e Adams 1975). These proposals were responsible for the creation of a way of analysis that still present in the current debate about this subject. This work pursues to explain the principal assumptions held within these proposals. According to certain disambiguation techniques from Bennett (2003) and Lycan (2005), this work tries to explicit how these assumptions connect to the aims sought by the initial approaches. The following results show that there is a not declared presumption, the definition of the object of study of these theories, i.e., the definition of conditional sentence. This work argues that despite of not explicitly declared the definition of the study object has a central role in the intelligibility of the debate itself

Sistemas de lógica modal em dedução natural

Formalization of logical systems in natural deduction brings many metatheoretical advantages, which Normalization proof is always highlighted. Modal logic systems, until very recently, were not routinely formalized in natural deduction, though some formulations and Normalization proofs are known. This work is a presentation of some important known systems of modal logic in natural deduction, and some Normalization procedures for them, but it is also and mainly a presentation of a hierarchy of modal logic systems in natural deduction, from K until S5, together with an outline of a Normalization proof for the system K, which is a model for Normalization in other systems