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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.
1

The history and development of logarithms

Bennett, Meaghan Whitley 2009 August 1900 (has links)
This paper outlines the evolution of the logarithm from the days of Archimedes to the logarithm now used in modern mathematics. Each type of logarithm developed had its particular usefulness. The Archimedean logarithm helped astronomers by drastically shortening the time it took to multiply large numbers, while Napier’s logarithm could be used as a tool to solve velocity problems. With the discovery of the number e, the natural logarithm was developed. Due to the frequent use of e, many of the properties of logarithms were defined to work nicely for the natural logarithm to make calculations easier. This paper will explain the proofs and connections of such properties in a way that could be presented in a calculus class. / text
2

Zavedení exponenciály a logaritmu / Defining the exponential function and logarithm

Franc, Tomáš January 2010 (has links)
In this diploma thesis we will introduce six de nitions of the natural exponential function and ve de nitions of the natural logarithmic function. We will prove the de nitions' correctness, derive basic properties of both funcions and show the equivalence of all de nitions for each function. We will see how these funcions are de ned in some textbooks for universities and in textbooks for grammar schools. We will discuss the bene ts and drawbacks of all de nitions and will use the criteria such as required theory and difficulty or length of proofs. At the end of the thesis we will make some recommendations regarding de ning these functions at high schools and universities and we will give several suggestions for an additional research.
3

Second moments of incomplete Eisenstein series and applications

Yu, Shucheng January 2018 (has links)
Thesis advisor: Dubi Kelmer / We prove a second moment formula for incomplete Eisenstein series on the homogeneous space Γ\G with G the orientation preserving isometry group of the real (n + 1)-dimensional hyperbolic space and Γ⊂ G a non-uniform lattice. This result generalizes the classical Rogers' second moment formula for Siegel transform on the space of unimodular lattices. We give two applications of this moment formula. In Chapter 5 we prove a logarithm law for unipotent flows making cusp excursions in a non-compact finite-volume hyperbolic manifold. In Chapter 6 we study the counting problem counting the number of orbits of Γ-translates in an increasing family of generalized sectors in the light cone, and prove a power saving estimate for the error term for a generic Γ-translate with the exponent determined by the largest exceptional pole of corresponding Eisenstein series. When Γ is taken to be the lattice of integral points, we give applications to the primitive lattice points counting problem on the light cone for a generic unimodular lattice coming from SO₀(n+1,1)(ℤ\SO₀(n+1,1). / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Mathematics.
4

The law of the iterated logarithm for tail sums

Ghimire, Santosh January 1900 (has links)
Doctor of Philosophy / Department of Mathematics / Charles N. Moore / The main purpose of this thesis is to derive the law of the iterated logarithm for tail sums in various contexts in analysis. The various contexts are sums of Rademacher functions, general dyadic martingales, independent random variables and lacunary trigonometric series. We name the law of the iterated logarithm for tail sums as tail law of the iterated logarithm. We first establish the tail law of the iterated logarithm for sums of Rademacher functions and obtain both upper and lower bound in it. Sum of Rademacher functions is a nicely behaved dyadic martingale. With the ideas from the Rademacher case, we then establish the tail law of the iterated logarithm for general dyadic martingales. We obtain both upper and lower bound in the case of martingales. A lower bound is obtained for the law of the iterated logarithm for tail sums of bounded symmetric independent random variables. Lacunary trigonometric series exhibit many of the properties of partial sums of independent random variables. So we finally obtain a lower bound for the tail law of the iterated logarithm for lacunary trigonometric series introduced by Salem and Zygmund.
5

A Cryptographic Attack: Finding the Discrete Logarithm on Elliptic Curves of Trace One

Bradley, Tatiana 01 January 2015 (has links)
The crux of elliptic curve cryptography, a popular mechanism for securing data, is an asymmetric problem. The elliptic curve discrete logarithm problem, as it is called, is hoped to be generally hard in one direction but not the other, and it is this asymmetry that makes it secure. This paper describes the mathematics (and some of the computer science) necessary to understand and compute an attack on the elliptic curve discrete logarithm problem that works in a special case. The algorithm, proposed by Nigel Smart, renders the elliptic curve discrete logarithm problem easy in both directions for elliptic curves of so-called "trace one." The implication is that these curves can never be used securely for cryptographic purposes. In addition, it calls for further investigation into whether or not the problem is hard in general.
6

Sparky the Saguaro: Teaching Experiments Examining Students' Development of the Idea of Logarithm

January 2018 (has links)
abstract: There have been a number of studies that have examined students’ difficulties in understanding the idea of logarithm and the effectiveness of non-traditional interventions. However, there have been few studies that have examined the understandings students develop and need to develop when completing conceptually oriented logarithmic lessons. In this document, I present the three papers of my dissertation study. The first paper examines two students’ development of concepts foundational to the idea of logarithm. This paper discusses two essential understandings that were revealed to be problematic and essential for students’ development of productive meanings for exponents, logarithms and logarithmic properties. The findings of this study informed my later work to support students in understanding logarithms, their properties and logarithmic functions. The second paper examines two students’ development of the idea of logarithm. This paper describes the reasoning abilities two students exhibited as they engaged with tasks designed to foster their construction of more productive meanings for the idea of logarithm. The findings of this study provide novel insights for supporting students in understanding the idea of logarithm meaningfully. Finally, the third paper begins with an examination of the historical development of the idea of logarithm. I then leveraged the insights of this literature review and the first two papers to perform a conceptual analysis of what is involved in learning and understanding the idea of logarithm. The literature review and conceptual analysis contributes novel and useful information for curriculum developers, instructors, and other researchers studying student learning of this idea. / Dissertation/Thesis / Doctoral Dissertation Mathematics 2018
7

Função exponencial e logarítmica / Function exponential and logarithmic

Silva, Rodrigo Felipe da [UNESP] 08 July 2016 (has links)
Submitted by Rodrigo Felipe da Silva null (rodrigofelipeww@hotmail.com) on 2016-08-29T00:06:15Z No. of bitstreams: 1 dissertacao final.pdf: 3098255 bytes, checksum: 38c69f33c20861a5bc6a8a6953fa8352 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-30T16:52:00Z (GMT) No. of bitstreams: 1 silva_rf_me_sjrp.pdf: 3098255 bytes, checksum: 38c69f33c20861a5bc6a8a6953fa8352 (MD5) / Made available in DSpace on 2016-08-30T16:52:00Z (GMT). No. of bitstreams: 1 silva_rf_me_sjrp.pdf: 3098255 bytes, checksum: 38c69f33c20861a5bc6a8a6953fa8352 (MD5) Previous issue date: 2016-07-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No ensino da matemática um dos assuntos mais desa adores aos alunos do Ensino Médio é o de funções exponenciais e logarítmicas, sendo que grande parte dos alunos possuem difi culdades de compreensão e resolução dos exercícios propostos. Dessa maneira o trabalho em tela tem como objetivo precípuo o ensino de funções exponenciais e logarítmicas, visando apresentar aos docentes a possibilidade de ensinar o conteúdo de maneira mais atrativa e acessível aos seus alunos. Para tanto, a pesquisa se valeu de levantamento bibliográ fico e documental acerca da temática abordada. Salienta-se que ao iniciar o ensino de funções é preciso fazer um resgate histórico do conteúdo, buscando desvelar suas origens. Posteriormente o trabalho traz as concepções do tema segundo os documentos o ciais. A m de concretizar o estudo trabalha-se com o uso das defi nições aritméticas e geométricas, pois são fundamentais para o entendimento das funções, e também com situações problema contextualizadas, buscando envolver os alunos no processo de ensino aprendizagem promovendo o levantamento de hipóteses e consolidando a aprendizagem. Essas situações problemas serão difundidas por meio de atividades propostas nas quais pretende-se explorar a caracterização da função logarítmica e exponencial, buscando relacioná-las ao contexto do educando, em situações que poderiam ocorrer em seu cotidiano, para isso propomos alguns exemplos de atividades, como: a utilização do BRO ce Calc no Ensino de potenciação com números irracionais, o jogo de xadrez, mágica do baralho e a resolução de problemas da OBMEP e do ENEM. / In teaching mathematics one of most challenging subjects to middle school students is of exponential and logarithmic functions, being that most of the students have difficulties in understanding and addressing the proposed exercises. In this way the work on canvas aims foremost teaching of exponential and logarithmic functions, n order to present to teachers the possibility to teach the content more attractive and accessible to his students. To this end, the research used for bibliographical and documental about the theme addressed.It should be noted that the starting teaching duties must make a historic rescue of the contents, looking for their origins unveiling. In order to implement the study works with the use of arithmetic and geometric definitions, because they are fundamental to the understanding of the functions, and also with contextualized problem situations, seeking to engage students in teaching learning process promoting the survey of hypotheses and consolidating learning. These problems will be disseminated through activities in which it is intended to explore the characterization of logarithmic and exponential function, seeking to relate them to the context of educating, in situations that could occur in their daily lives, for this we propose some examples of activities, such as: libreoffice Calc use in teaching empowerment with irrational numbers, the game of chess, magic of the deck and the troubleshooting of OBMEP and ENEM.
8

Computation of Initial State for Tail-Biting Trellis

Chen, Yiqi 07 October 2005 (has links)
No description available.
9

The Discrete Logarithm Problem in Finite Fields of Small Characteristic / Das diskrete Logarithmusproblem in endlichen Körpern kleiner Charakteristik

Zumbrägel, Jens 14 March 2017 (has links) (PDF)
Computing discrete logarithms is a long-standing algorithmic problem, whose hardness forms the basis for numerous current public-key cryptosystems. In the case of finite fields of small characteristic, however, there has been tremendous progress recently, by which the complexity of the discrete logarithm problem (DLP) is considerably reduced. This habilitation thesis on the DLP in such fields deals with two principal aspects. On one hand, we develop and investigate novel efficient algorithms for computing discrete logarithms, where the complexity analysis relies on heuristic assumptions. In particular, we show that logarithms of factor base elements can be computed in polynomial time, and we discuss practical impacts of the new methods on the security of pairing-based cryptosystems. While a heuristic running time analysis of algorithms is common practice for concrete security estimations, this approach is insufficient from a mathematical perspective. Therefore, on the other hand, we focus on provable complexity results, for which we modify the algorithms so that any heuristics are avoided and a rigorous analysis becomes possible. We prove that for any prime field there exist infinitely many extension fields in which the DLP can be solved in quasi-polynomial time. Despite the two aspects looking rather independent from each other, it turns out, as illustrated in this thesis, that progress regarding practical algorithms and record computations can lead to advances on the theoretical running time analysis -- and the other way around. / Die Berechnung von diskreten Logarithmen ist ein eingehend untersuchtes algorithmisches Problem, dessen Schwierigkeit zahlreiche Anwendungen in der heutigen Public-Key-Kryptographie besitzt. Für endliche Körper kleiner Charakteristik sind jedoch kürzlich erhebliche Fortschritte erzielt worden, welche die Komplexität des diskreten Logarithmusproblems (DLP) in diesem Szenario drastisch reduzieren. Diese Habilitationsschrift erörtert zwei grundsätzliche Aspekte beim DLP in Körpern kleiner Charakteristik. Es werden einerseits neuartige, erheblich effizientere Algorithmen zur Berechnung von diskreten Logarithmen entwickelt und untersucht, wobei die Laufzeitanalyse auf heuristischen Annahmen beruht. Unter anderem wird gezeigt, dass Logarithmen von Elementen der Faktorbasis in polynomieller Zeit berechnet werden können, und welche praktischen Auswirkungen die neuen Verfahren auf die Sicherheit paarungsbasierter Kryptosysteme haben. Während heuristische Laufzeitabschätzungen von Algorithmen für die konkrete Sicherheitsanalyse üblich sind, so erscheint diese Vorgehensweise aus mathematischer Sicht unzulänglich. Der Aspekt der beweisbaren Komplexität für DLP-Algorithmen konzentriert sich deshalb darauf, modifizierte Algorithmen zu entwickeln, die jegliche heuristische Annahme vermeiden und dessen Laufzeit rigoros gezeigt werden kann. Es wird bewiesen, dass für jeden Primkörper unendlich viele Erweiterungskörper existieren, für die das DLP in quasi-polynomieller Zeit gelöst werden kann. Obwohl die beiden Aspekte weitgehend unabhängig voneinander erscheinen mögen, so zeigt sich, wie in dieser Schrift illustriert wird, dass Fortschritte bei praktischen Algorithmen und Rekordberechnungen auch zu Fortentwicklungen bei theoretischen Laufzeitabschätzungen führen -- und umgekehrt.
10

Pokročilé metody hledání diskrétního logaritmu / Advanced techniques for calculations of discrete logarithm

Matocha, Vojtěch January 2013 (has links)
Let G be a finite cyclic group. Solving the equation g^x = y for a given generator g and y is called the discrete logarithm problem. This problem is at the core of many modern cryptographic transformations. In this paper we provide a survey of algorithms to attack this problem, including the function field sieve, the fastest known algorithm applicable to the multiplicative group of a finite field. We also discuss the index calculus algorithm and some techniques improving its performance: the Coppersmith's algorithm and the polynomial sieving. The most important contribution of this paper is a C-language implementation of the function field sieve and its application to real inputs.

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