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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Θεμελίωση του σώματος των πραγματικών αριθμών. Ισχύς και διάταξη αυτού

Γκίκα, Κατερίνα Ν. 27 August 2008 (has links)
Στη μελέτη αυτή δεχόμεθα ως βασικές έννοιες την έννοια του συνόλου, την έννοια της συνάρτησης και την έννοια των φυσικών αριθμών. Ορίζουμε και αποδεικνύουμε ό,τι χρειάζεται από την θεωρία των συνόλων για να κατασκευάσουμε το σύστημα των ακεραίων αριθμών, το σύστημα των ρητών και τελικά το σύστημα των πραγματικών αριθμών. Σε όλα τα παραπάνω συστήματα ορίζεται η έννοια της διάταξης και αποδεικνύεται ότι το σύστημα των ρητών αριθμών είναι ένα Αρχιμήδειο σώμα που είναι πυκνό υποσύνολο του σώματος των πραγματικών αριθμών. Εν συνεχεία αποδεικνύονται οι χαρακτηριστικές ιδιότητες του σώματος των πραγματικών αριθμών, δηλαδή η ιδιότητα της πληρότητας (κάθε ακολουθία Cauchy συγκλίνει) και η ιδιότητα του άνω φράγματος (κάθε μή κενό υποσύνολο ,που είναι φραγμένο εκ των άνω, έχει ένα ελάχιστο άνω φράγμα (supremum). Όλα τα παραπάνω και πολλά σχετικά με αυτά περιέχονται στα κεφάλαια 1 ως και 7. Το κεφάλαιο 8 περιέχει μία συλλογή αποτελεσμάτων σχετικά με τους πληθικούς αριθμούς, οι οποίοι ορίζονται και μελετώνται στο κεφάλαιο 3. Πολλά από τα αποτελέσματα αυτά αφορούν στον πληθικό αριθμό των πραγματικών αριθμών. Στο κεφάλαιο 9 ορίζονται όλες οι έννοιες που χρειάζονται για να γίνουν κατανοητά τα αποτελέσματα σχετικά με την θεωρία των καλώς διατεταγμένων συνόλων και την θεωρία των διατακτικών αριθμών (ordinal numbers). Των κεφαλαίων 1, 2, 3 προτάσσεται ιστορικό σημείωμα που αφορά τις έννοιες που αναπτύσσονται σε αυτά. Ανάλογο ιστορικό σημείωμα προτάσσεται των υπολοίπων κεφαλαίων. / In this study, I acknowledge as basic meanings, the meaning of the set, the meaning of the function and the meaning of natural numbers. We define and prove whatever is needed from the theory of sets in order to construct the system of integral numbers, the system of rational numbers and ultimately the field of real numbers. In all the above systems the meaning of arrangement is defined and it is proven that the system of rational numbers is an Archimedean field which is a dense subset of the field of real numbers. Next, the characteristic properties of the field of real numbers are proven, i.e. the property of compactness (each sequence Cauchy converges)and the property of the upper bound (each non empty subset, which is bounded from above , has a minimum upper bound (supremum). All of the above and many other things related to this are contained in chapters 1 to 7. Chapter 8 contains a selection of results relating to cardinal numbers, which are defined and studied in chapter 3 Many of these results relate to cardinal number of reals numbers. In chapter 9, all the meanings which are needed in order for the results relating to the theory of the well-ordered sets and the theory of ordinal numbers, to become understood are included. Preceeding chapters 1, 2, 3 there is a historic note relating to the meanings which are developed in them. There is a corresponding historic note preceeding the rest of the chapters.
52

Uma construção geométrica dos números reais

Santos, Simone de Carvalho 31 August 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aims to present a geometric construction of real numbers characterizing them as numbers that express a measure. In this construction, each point in an oriented line represents the measure of a segment (a real number). Based on ve axioms of Euclidean geometry it was de ned an order relation, a method to add and multiply points so that it was possible to demonstrate that the line has a full ordered body of algebraic structure that we call the set of real numbers. To do so, it were presented historical elements that allow us to understand the emergence of irrational numbers as a solution to the insu ciency of rational numbers with respect to the measuring problem, the evolution of the concept of number, as well as the importance that the strict construction of real numbers had to the Foundations of Mathematics. We display a construction of rational numbers from the integernumbers as motivation for construction of numerical sets. Using the notion of measure,we show a geometric interpretation of rational numbers linking them to the points of an oriented line to demonstrate that they leave holes in the line and conclude on the need to build a set that contains the rational numbers and that ll all the points of a line. The theme is of utmost importance to the teaching of mathematics because one of the major goal of basic education is to promote understanding of numbers and operations, to develop number sense and to develop uency in the calculation. To achieve this, it is necessary to assimilate the r / O presente trabalho tem por objetivo apresentar uma construção geométrica dos números reais caracterizando-os como números que expressam uma medida. Nesta construção cada ponto de uma reta orientada representa a medida de um segmento (um número real), com base nos cinco axiomas da geometria euclidiana de niu-se uma relação de ordem, um método para somar e multiplicar pontos de tal forma que fosse possível demonstrar que a reta possui uma estrutura algébrica de corpo ordenado completo a qual chamamos de conjunto dos números reais. Para tanto, foram apresentados elementos históricos que permitem compreender o surgimento dos números irracionais como solução para a insu - ciência dos números racionais no que diz respeito ao problema de medida, a evolução do próprio conceito de número, bem como a importância que a construção rigorosa dos nú- meros reais tiveram para os Fundamentos da Matemática. Exibimos uma construção dos números racionais a partir dos números inteiros como motivação para construções de conjuntos numéricos. Usando a noção de medida mostramos uma interpretação geométrica dos números racionais associando-os aos pontos de uma reta orientada para demonstrar que eles deixam buracos na reta e concluir sobre a necessidade de construir um conjunto que contenha os números racionais e que preencham todos os pontos de uma reta. O tema é de extrema importância para o ensino da matemática, visto que um dos principais objetivos do ensino básico é promover a compreensão dos números e das operações, desenvolver o sentido de número e desenvolver a uência no cálculo, sendo necessário para tal assimilar os números reais, em especial os irracionais, os quais são tratados a partir do ensino fundamental.
53

Construção dos números reais via cortes de Dedekind / Construction of the real numbers via Dedekind cuts

Thiago Trindade Pimentel 03 September 2018 (has links)
O objetivo desta dissertação é apresentar a construção dos números reais a partir de cortes de Dedekind. Para isso, vamos estudar os números naturais, os números inteiros, os números racionais e as propriedades envolvidas. Então, a partir dos números racionais, iremos construir o corpo dos números reais e estabelecer suas propriedades. Um corte de Dedekind, assim nomeado em homenagem ao matemático alemão Richard Dedekind, é uma partição dos números racionais em dois conjuntos não vazios A e B em que cada elemento de A é menor do que todos os elementos de B e A não contém um elemento máximo. Se B contiver um elemento mínimo, então o corte representará este elemento mínimo, que é um número racional. Se B não contiver um elemento mínimo, então o corte definirá um único número irracional, que preenche o espaço entre A e B. Desta forma, pode-se construir o conjunto dos números reais a partir dos racionais e estabelecer suas propriedades. Esta dissertação proporcionará aos estudantes do Ensino Médio, interessados em Matemática, uma formação sólida em um de seus pilares, que é o conjunto dos números reais e suas operações algébricas e propriedades. Isso será muito importante para a formação destes alunos e sua atuação educacional. / The purpose of this dissertation is to present the construction of the real numbers from Dedekind cuts. For this, we study the natural numbers, the integers, the rational numbers and some properties involved. Then, based on the rational numbers, we construct the field of the real numbers and establish their properties. A Dedekind cut, named after the German mathematician Richard Dedekind, is a partition of the rational numbers into two non-empty sets A and B, such that each element of A is smaller than all elements of B and A does not contain a maximum element. If B contains a minimum element, then the cut represents this minimum element, which is a rational number. If B does not contain a minimal element, then the cut defines a single irrational number, which \"fills the gap\" between A and B. In this way, one can construct the set of real numbers from the rationals and establish their properties. This dissertation provides students who like Mathematics a solid basis in one of the pillars of Mathematics, which is the set of real numbers and their algebraic operations and properties. This text will be very important for your educational background and performance.
54

Enquadramento de números racionais em intervalos de racionais: uma investigação com professores do ensino fundamental

Souza, Janaina Maria Lage de 29 May 2006 (has links)
Made available in DSpace on 2016-04-27T16:57:42Z (GMT). No. of bitstreams: 1 dissertacao_janaina_maria_lage_souza.pdf: 309247 bytes, checksum: 01af28b792f08537756e1b46462d92d0 (MD5) Previous issue date: 2006-05-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The basis for the present study were the activities developed by Régine Douady (1986) involving the framing of rational numbers on intervals, addressed to French students of the educational segment that corresponds to 1st-8th grades in Brazil. In the present study, those activities were updated taking into account elements from recent Brazilian investigations on the meanings assigned by Brazilian students of 1st-8th grades to relations and to order relations, and elements of the Brazilian Curricular Guidelines of 1997 and 1998. By applying the methodology of case study, and in the light of the notion of tool object dialectic of Régine Douady (1984), the updated activities were presented in eight sessions to two mathematics teachers of the 7th and 8th grades in a private school in the city of São Paulo, both of whom were experienced in working with this theoretical framework, with the purpose of investigating what aspects these teachers take into consideration when discussing and developing their lesson plans regarding those activities. Particular attention was given to the changes and adaptations they made to the activities in order to facilitate their use in the classroom, based on their teaching practice, the actual features of the school and educational system in which this study was conducted, the school s program, recent investigations conducted with Brazilian students, the Brazilian Curricular Guidelines of 1997 and 1998, and the theoretical framework developed by Douady. In the present study, this process has been termed reupdating / A partir de atividades de Régine Douady (1986) envolvendo enquadramento de números racionais em intervalos, voltadas a alunos franceses do segmento de ensino correspondente ao ensino fundamental do Brasil, realizou-se na presente pesquisa uma atualização dessas atividades, estabelecendo diálogo com pesquisas brasileiras recentes sobre significados atribuídos por estudantes brasileiros do ensino fundamental a relações e relações de ordem e com os Parâmetros Curriculares Nacionais de 1997 e 1998. Recorrendo-se à metodologia de estudo de caso, e à luz da noção de dialética ferramenta objeto de Régine Douady (1984), as atividades atualizadas foram apresentadas em oito sessões a duas docentes do ensino fundamental, de sétima e oitava séries, de uma escola privada da cidade de São Paulo, experientes no trabalho com esse quadro teórico, com o objetivo de investigar o que essas professoras levam em consideração ao discutirem e elaborarem planejamentos de aulas referentes a essas atividades. Foi dada particular atenção às alterações e adaptações feitas por elas a essas atividades, de modo a favorecer sua proposição em sala de aula, tendo em vista sua prática docente, a realidade escolar em que se realizou este estudo, o programa dessa escola, pesquisas recentes realizadas com alunos brasileiros, os Parâmetros Curriculares Nacionais de 1997 e 1998 e o quadro teórico de Douady. Esse processo foi por nós denominado de reatualização
55

Visualisation, navigation and mathematical perception: a visual notation for rational numbers mod1

Tolmie, Julie, julie.tolmie@techbc.ca January 2000 (has links)
There are three main results in this dissertation. The first result is the construction of an abstract visual space for rational numbers mod1, based on the visual primitives, colour, and rational radial direction. Mathematics is performed in this visual notation by defining increasingly refined visual objects from these primitives. In particular, the existence of the Farey tree enumeration of rational numbers mod1 is identified in the texture of a two-dimensional animation. ¶ The second result is a new enumeration of the rational numbers mod1, obtained, and expressed, in abstract visual space, as the visual object coset waves of coset fans on the torus. Its geometry is shown to encode a countably infinite tree structure, whose branches are cosets, nZ+m, where n, m (and k) are integers. These cosets are in geometrical 1-1 correspondence with sequences kn+m, (of denominators) of rational numbers, and with visual subobjects of the torus called coset fans. ¶ The third result is an enumeration in time of the visual hierarchy of the discrete buds of the Mandelbrot boundary by coset waves of coset fans. It is constructed by embedding the circular Farey tree geometrically into the empty internal region of the Mandelbrot set. In particular, coset fans attached to points of the (internal) binary tree index countably infinite sequences of buds on the (external) Mandelbrot boundary.

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