Submitted by bruna ortiz (brunaortiz.f@gmail.com) on 2016-07-18T13:54:46Z No. of bitstreams: 1 Dissertação-João Cruz Neto.pdf: 2926026 bytes, checksum: 80af843dade67c0e4a42dffdc933b945 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-07-27T13:25:52Z (GMT) No. of bitstreams: 1 Dissertação-João Cruz Neto.pdf: 2926026 bytes, checksum: 80af843dade67c0e4a42dffdc933b945 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-07-27T13:28:25Z (GMT) No. of bitstreams: 1 Dissertação-João Cruz Neto.pdf: 2926026 bytes, checksum: 80af843dade67c0e4a42dffdc933b945 (MD5) / Made available in DSpace on 2016-07-27T13:28:25Z (GMT). No. of bitstreams: 1 Dissertação-João Cruz Neto.pdf: 2926026 bytes, checksum: 80af843dade67c0e4a42dffdc933b945 (MD5) Previous issue date: 2015-08-12 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Many math topics are apresented in basic education without a meaningful context, both in textbooks and in the classroom, this is, for exemple, with the natural logarithm function and the exponential function. This work will make a geometric approach these issues by establishing an inter-relationship between the area of a track x y 􀀀 1 = 0 hyperbole with the natural logarithm, introducing some basic aspects of the theory necessary to understand. The required prerequisites are the solid knowledge of the basic functions defined in the field of real numbers. Present a conceptual approach limits functions, sequences and numerical series, hyperbole and the study on the area of a track x y 􀀀 1 = 0 hyperbole, from this area define the natural logarithm and their properties, the natural logarithm function and its inverse, the exponential function. Is inevitable, considering our proposal for this work, that some results are presented, accepted and used in demonstration. / Muitos temas da Matemática são apresentados no ensino básico sem um contexto significativo, tanto nos livros didáticos quanto em sala de aula, isso ocorre, por exemplo, com a função logaritmo natural e a função exponencial. Neste trabalho faremos uma abordagem geométrica desses temas estabelecendo uma inter-relação entre a área de uma faixa da hipérbole x y􀀀1 = 0 com o logaritmo natural, introduzindo alguns aspectos básicos da teoria necessária a sua compreensão. Os prerrequisitos exigidos são os conhecimentos sólidos das funções elementares definidas no campo dos números reais. Apresentamos uma abordagem conceitual sobre limites de funções, sequências e séries numéricas, a hipérbole e o estudo sobre a área de uma faixa da hipérbole x y 􀀀 1 = 0; para a partir desta área definirmos o logaritmo natural e suas propriedades, a função logaritmo natural e sua inversa, a função exponencial. É inevitável, levando em conta a nossa proposta para esse trabalho, que alguns resultados sejam apresentados, admitidos e usados sem demonstração.

Este trabalho tem como objetivo principal contribuir para o aperfeiçoamento do professor de matemática seja ele em formação ou em atuação. Buscamos oferecer um material que possa servir de referência técnica, histórica e epistemológica para o estudo do Logaritmo Natural. Discutimos aqui o conceito de Conhecimento Especializado do Conteúdo, cunhado por pesquisadores da Universidade de Michigan e liderados por Deborah Ball. Em seu artigo Content Knowledge for Teaching: What Makes It Special? (2008), eles levantam a questão \"Qual matemática o professor deve conhecer para dar cabo do trabalho de ensinar?\", dado que o conhecimento matemático necessário para o docente difere do conhecimento matemático requerido em outras profissões. Fazemos aqui uma análise crítica da abordagem utilizada para o tema em alguns livros didáticos de Ensino Médio, descrevemos de modo detalhado a construção da Função Logarítmica como realmente ocorreu no século XVII, ou seja, por meio de áreas de regiões sob a curva xy = 1, e definimos a função exponencial como a inversa dela, enfoque esse com caráter fortemente geométrico e que deu origem à noção de integral definida. Mostramos também a estreita relação existente entre as Progressões Aritméticas, Geométricas, Trigonometria e o próprio tema principal. Obtemos ainda a formalização do número irracional e tanto pelo método tradicional usado em livros de Cálculo e Análise como a decorrente da teoria apresentada. Por fim, apresentamos algumas situações curiosas que envolvem direta ou indiretamente essa constante e que podem ser trabalhadas com alunos da Educação Básica. / The main objective of this work is to contribute to the improvement of the mathematics teacher, whether in training or acting. We seek to offer a material that can serve as a technical, historical and epistemological reference for the study of the Natural Logarithm. We discuss here the concept of Specialized Content Knowledge, coined by University of Michigan researchers and led by Deborah Ball. In your article Content Knowledge for Teaching: What Makes It Special? (2008), they raise the question \"What mathematics does the teacher need to know for teaching?\", since the mathematical knowledge required for the teacher differs from the mathematical knowledge required in other professions. Here we present a critical analysis of the approach used for the subject in some high school textbooks. We describe in detail the construction of the Logarithmic Function as actually occurred in the seventeenth century, that is, through areas of regions under the curve xy = 1, and we define the exponential function as the inverse of it, a focus with a strongly geometric character that gave rise to the notion of definite integral. We also show the close relationship between Arithmetic, Geometric, Trigonometry and the main theme itself. We also obtain the formalization of the irrational number e, both by the traditional method used in Calculus and Analysis books and by the theory presented. Finally, we present some curious situations that directly or indirectly involve this constant and that can be worked with Basic Education students.

In this thesis, we study the discrete logarithm problem in the context of TFNP - the complexity class of search problems with a syntactically guaranteed existence of a solution for all instances. Our main results show that suitable variants of the discrete logarithm problem, which we call Index and DLog, are complete for the classes PPP and PWPP, respectively. Additionally, our reductions provide new structural insights into PWPP by establishing two new PWPP-complete problems. First, the problem Dove, a relaxation of the PPP-complete problem Pigeon. Dove is the first PWPP-complete problem not defined in terms of an explicitly shrinking function. Second, the problem Claw, a total search problem capturing the computational complexity of breaking claw-free permuta- tions. In the context of TFNP, the PWPP-completeness of Claw matches the known intrinsic relationship between collision-resistant hash functions and claw-free permuta- tions established in the cryptographic literature. 1

No description available.

Seit W. Diffie und M. Hellman im Jahr 1976 ihren Ansatz für einen sicheren kryptographischen Schlüsselaustausch vorgestellten, ist der sogenannte Diskrete Logarithmus zu einem zentrales Thema der Kryptoanalyse geworden. Dieser stellt eine Erweiterung des bekannten Logarithmus auf beliebige endliche Gruppen dar. In der vorliegenden Dissertation werden zwei von C. Diem eingeführte Algorithmen untersucht, mit deren Hilfe der diskrete Logarithmus in der Picardgruppe glatter, nichthyperelliptischer Kurven vom Geschlecht g > 3 bzw. g > 4 über endlichen Körpern berechnet werden kann. Beide Ansätze basieren auf der sogenannten Indexkalkül-Methode und benutzen zur Erzeugung der dafür benötigten Relationen spezielle Linearsysteme, welche durch Schneiden von ebenen Modellen der Kurve mit Geraden erzeugt werden. Um Aussagen zur Laufzeit der Algorithmen tätigen zu können, werden verschiedene Sätze über die Geometrie von Kurven bewiesen. Als zentrale Aussage wird zum einem gezeigt, dass ebene Modelle niedrigen Grades effizient berechnet werden können. Zum anderen wird bewiesen, dass sich bei genügend großem Grundkörper die Anzahl der vollständig über dem Grundkörper zerfallenden Geraden wie heuristisch erwartet verhällt. Für beide Aussagen werden dabei Familien von Kurven betrachtet und diese gelten daher uniform für alle glatten, nichthyperelliptischen Kurven eines festen Geschlechts. Die genannten Resultate führen schlussendlich zu dem Beweis einer erwarteten Laufzeit von O(q^(2-2/(g-1))) für den ersten der beiden Algorithmen, wobei q die Anzahl der Elemente im Grundkörper darstellt. Der zweite Algoritmus verbessert dies auf eine heuristische Laufzeit in O(q^(2-2/(g-2))), imdem er Divisoren von höherem Spezialiätsgrad erzeugt. Es wird bewiesen, dass dieser Ansatz für einen uniform gegen 1 konvergierenden Anteil an glatten, nichthyperelliptischen Kurven eines festen Geschlechts über Grundkörpern großer Charakteristik eine große Anzahl an Relationen erzeugt. Wiederum werden zum Beweis der zugrundeliegenden geometrischen Aussagen Familien von Kurven betrachtet, um so die Uniformität zu gewährleisten. Beide Algorithmen wurden zudem implementiert. Zum Abschluss der Arbeit werden die Ergebnisse der entsprechenden Experimente vorgestellt und eingeordnet.

Neste trabalho são apresentadas duas propostas de sequências didáticas para ensino de logaritmos. A primeira delas é destinada ao aperfeiçoamento de professores de Matemática e a outra, para alunos de Ensino Médio. Tais sequências foram desenvolvidas com base em pesquisas realizadas pelo Prof. João Pedro da Ponte sobre o processo de investigação matemática. A sequência didática para professores foi aplicada no Centro de Aperfeiçoamento do Ensino de Matemática do Instituto de Matemática e Estatística da Universidade de São Paulo (CAEM IME USP). Já a sequência para alunos foi aplicada em uma escola da rede estadual situada no município de São Paulo. Ambas foram analisadas sob os pontos de vista da eficiência e adequação, bem como da clareza das ideias apresentadas. As sequências didáticas têm como ponto de partida a observação das propriedades comuns a várias tabelas, cada uma contendo uma progressão geométrica ao lado de uma progressão aritmética. Tais propriedades caracterizam o que virá a ser definido como logaritmo. Essa introdução ao conceito de logaritmo é diferente da usual, que se baseia na solução de uma equação exponencial. O processo de investigação matemática visa a um aprendizado eficaz por parte do aluno, proporcionado por atividades que conduzam o aluno, de forma gradual, a fazer descobertas, formular conjecturas e buscar validações. Tais investigações são coordenadas e supervisionadas pelo professor, cujo papel é fundamental no processo de construção do conhecimento. / This dissertation presents two didactic sequences for teaching and learning logarithms. One of them aims at Mathematics teachers and is designed for improving their knowledge. The other sequence is meant to be used on high school students. Both didactic sequences were developed based upon research carried out by Professor João Pedro da Ponte on Mathematical Investigations. The didactic sequence for teachers was applied at CAEM IME USP. The one for students was applied at a state school in the city of São Paulo. They were analysed from the points of view of efficiency and of adequacy, as well as of the clarity of the presented ideas. The didactic sequences start with the observation of properties common to multiple tables, each containing a geometric progression side by side with an arithmetic progression. The observed properties characterize what will be later defined as logarithm. Such introduction to the concept of logarithm is different from the usual, which is based on the solution of an exponential equation. The Mathematical Investigation process aims at an effective learning by the students, which is provided by activities that lead the student to gradually make discoveries, formulate conjectures, and search for validations. These investigations are coordinated and supervised by the teacher, whose role in the knowledge construction process is fundamental.

Neste trabalho são apresentadas duas propostas de sequências didáticas para ensino de logaritmos. A primeira delas é destinada ao aperfeiçoamento de professores de Matemática e a outra, para alunos de Ensino Médio. Tais sequências foram desenvolvidas com base em pesquisas realizadas pelo Prof. João Pedro da Ponte sobre o processo de investigação matemática. A sequência didática para professores foi aplicada no Centro de Aperfeiçoamento do Ensino de Matemática do Instituto de Matemática e Estatística da Universidade de São Paulo (CAEM IME USP). Já a sequência para alunos foi aplicada em uma escola da rede estadual situada no município de São Paulo. Ambas foram analisadas sob os pontos de vista da eficiência e adequação, bem como da clareza das ideias apresentadas. As sequências didáticas têm como ponto de partida a observação das propriedades comuns a várias tabelas, cada uma contendo uma progressão geométrica ao lado de uma progressão aritmética. Tais propriedades caracterizam o que virá a ser definido como logaritmo. Essa introdução ao conceito de logaritmo é diferente da usual, que se baseia na solução de uma equação exponencial. O processo de investigação matemática visa a um aprendizado eficaz por parte do aluno, proporcionado por atividades que conduzam o aluno, de forma gradual, a fazer descobertas, formular conjecturas e buscar validações. Tais investigações são coordenadas e supervisionadas pelo professor, cujo papel é fundamental no processo de construção do conhecimento. / This dissertation presents two didactic sequences for teaching and learning logarithms. One of them aims at Mathematics teachers and is designed for improving their knowledge. The other sequence is meant to be used on high school students. Both didactic sequences were developed based upon research carried out by Professor João Pedro da Ponte on Mathematical Investigations. The didactic sequence for teachers was applied at CAEM IME USP. The one for students was applied at a state school in the city of São Paulo. They were analysed from the points of view of efficiency and of adequacy, as well as of the clarity of the presented ideas. The didactic sequences start with the observation of properties common to multiple tables, each containing a geometric progression side by side with an arithmetic progression. The observed properties characterize what will be later defined as logarithm. Such introduction to the concept of logarithm is different from the usual, which is based on the solution of an exponential equation. The Mathematical Investigation process aims at an effective learning by the students, which is provided by activities that lead the student to gradually make discoveries, formulate conjectures, and search for validations. These investigations are coordinated and supervised by the teacher, whose role in the knowledge construction process is fundamental.

We create a dual-species ultracold neutral plasma (UNP) by photo-ionizing Yb and Ca atoms in a dual-species magneto-optical trap. Unlike single-species UNP expansion, these plasmas are well outside of the collisionless (Vlasov) approximation. We observe the mutual interaction of the Yb and Ca ions by measuring the velocity distribution for each ion species separately. We model the expansion using a fluid code including ion-ion friction and compare with experimental results to obtain a value of the Coulomb logarithm of Λ= 0.04.

<p>This thesis consists of four papers, all concerning random iteration of isometries. The papers are:</p><p>I. Ambroladze A, Ådahl M, Random iteration of isometries in unbounded metric spaces. Nonlinearity 16 (2003) 1107-1117.</p><p>II. Ådahl M, Random iteration of isometries controlled by a Markov chain. Manuscript.</p><p>III. Ådahl M, Melbourne I, Nicol M, Random iteration of Euclidean isometries. Nonlinearity 16 (2003) 977-987.</p><p>IV. Johansson A, Ådahl M, Recurrence of a perturbed random walk and an iterated function system depending on a parameter. Manuscript.</p><p>In the first paper we consider an iterated function system consisting of isometries on an unbounded metric space. Under suitable conditions it is proved that the random orbit {<i>Z</i>n} ^∞_n=0, of the iterations corresponding to an initial point Z₀, “escapes to infinity" in the sense that <i>P</i>(<i>Z</i>n Є <i>K)</i> → 0, as <i>n</i> → ∞ for every bounded set <i>K</i>. As an application we prove the corresponding result in the Euclidean and hyperbolic spaces under the condition that the isometries do not have a common fixed point.</p><p>In the second paper we let a Markov chain control the random orbit of an iterated function system of isometries on an unbounded metric space. We prove under necessary conditions that the random orbit \escapes to infinity" and we also give a simple geometric description of these conditions in the Euclidean and hyperbolic spaces. The results generalises the results of Paper I.</p><p>In the third paper we consider the statistical behaviour of the reversed random orbit corresponding to an iterated function system consisting of a finite number of Euclidean isometries of <b>R</b>n. We give a new proof of the central limit theorem and weak invariance principles, and we obtain the law of the iterated logarithm. Our results generalise immediately to Markov chains. Our proofs are based on dynamical systems theory rather than a purely probabilistic approach.</p><p>In the fourth paper we obtain a suficient condition for the recurrence of a perturbed (one-sided) random walk on the real line. We apply this result to the study of an iterated function system depending on a parameter and defined on the open unit disk in the complex plane. </p>

This thesis consists of four papers, all concerning random iteration of isometries. The papers are: I. Ambroladze A, Ådahl M, Random iteration of isometries in unbounded metric spaces. Nonlinearity 16 (2003) 1107-1117. II. Ådahl M, Random iteration of isometries controlled by a Markov chain. Manuscript. III. Ådahl M, Melbourne I, Nicol M, Random iteration of Euclidean isometries. Nonlinearity 16 (2003) 977-987. IV. Johansson A, Ådahl M, Recurrence of a perturbed random walk and an iterated function system depending on a parameter. Manuscript. In the first paper we consider an iterated function system consisting of isometries on an unbounded metric space. Under suitable conditions it is proved that the random orbit {Zn} ∞n=0, of the iterations corresponding to an initial point Z0, “escapes to infinity" in the sense that P(Zn Є K) → 0, as n → ∞ for every bounded set K. As an application we prove the corresponding result in the Euclidean and hyperbolic spaces under the condition that the isometries do not have a common fixed point. In the second paper we let a Markov chain control the random orbit of an iterated function system of isometries on an unbounded metric space. We prove under necessary conditions that the random orbit \escapes to infinity" and we also give a simple geometric description of these conditions in the Euclidean and hyperbolic spaces. The results generalises the results of Paper I. In the third paper we consider the statistical behaviour of the reversed random orbit corresponding to an iterated function system consisting of a finite number of Euclidean isometries of <b>R</b>n. We give a new proof of the central limit theorem and weak invariance principles, and we obtain the law of the iterated logarithm. Our results generalise immediately to Markov chains. Our proofs are based on dynamical systems theory rather than a purely probabilistic approach. In the fourth paper we obtain a suficient condition for the recurrence of a perturbed (one-sided) random walk on the real line. We apply this result to the study of an iterated function system depending on a parameter and defined on the open unit disk in the complex plane.