The revolutionisation of international economies and monetary systems has been taking place since the early 1970s. This occurred due to the diminishing fixed exchange rate systems of, initially, the Gold Standard and subsequently the Bretton Woods System. The collapse of these systems, especially the Bretton Woods System, led to the almost free movement of exchange rates. The lack of restriction placed on the movement of currencies created volatile markets; which, in turn, gave rise to an innumerable amount of risks. In Correia, Holman and Jahreskog (2012) it was determined that an astonishing 74% of non-financial firms in South Africa hedge foreign exchange risk (the risk of currency movement). The 10% of firms which did not hedge any risks declared it was due to the lack of exposure to foreign exchange risks and that the cost of acquiring a hedging contract, in many cases, exceeded the contract’s benefits. In the aforementioned study it was also established that the extractive sector of South Africa is one of the industries referring from the use of hedges. The intention of this study is to improve the effectiveness of derivative instruments for companies in the extractive sector of South Africa exporting to the United States of America. South Africa is a large exporter and importer of goods, making it extremely important for market participants to determine the movement of the exchange rates. This estimates the amount of risk a company is willing to take and the amount of hedges they will use to protect themselves against inauspicious and adverse movements in the markets. Therefore, incorporated in this study is the use of risk management tools from the technical analysis to predict the exchange rates at which companies should have set their hedging contracts on specific dates. This analysis could enable companies to perform an internal control that is inexpensive and which reduces risks of foreign exporting. / MCom (Management Accountancy), North-West University, Potchefstroom Campus, 2014

The revolutionisation of international economies and monetary systems has been taking place since the early 1970s. This occurred due to the diminishing fixed exchange rate systems of, initially, the Gold Standard and subsequently the Bretton Woods System. The collapse of these systems, especially the Bretton Woods System, led to the almost free movement of exchange rates. The lack of restriction placed on the movement of currencies created volatile markets; which, in turn, gave rise to an innumerable amount of risks. In Correia, Holman and Jahreskog (2012) it was determined that an astonishing 74% of non-financial firms in South Africa hedge foreign exchange risk (the risk of currency movement). The 10% of firms which did not hedge any risks declared it was due to the lack of exposure to foreign exchange risks and that the cost of acquiring a hedging contract, in many cases, exceeded the contract’s benefits. In the aforementioned study it was also established that the extractive sector of South Africa is one of the industries referring from the use of hedges. The intention of this study is to improve the effectiveness of derivative instruments for companies in the extractive sector of South Africa exporting to the United States of America. South Africa is a large exporter and importer of goods, making it extremely important for market participants to determine the movement of the exchange rates. This estimates the amount of risk a company is willing to take and the amount of hedges they will use to protect themselves against inauspicious and adverse movements in the markets. Therefore, incorporated in this study is the use of risk management tools from the technical analysis to predict the exchange rates at which companies should have set their hedging contracts on specific dates. This analysis could enable companies to perform an internal control that is inexpensive and which reduces risks of foreign exporting. / MCom (Management Accountancy), North-West University, Potchefstroom Campus, 2014

Treatise (D.M.A.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Phyllotaxis, namely the arrangement of phylla (leaves, florets, etc.) has intrigued natural scientists for over four hundred years. Statistics show that about 90\% of the spiral patterns has their numbers of spirals belonging to two consecutive members of the regular Fibonacci sequence. (Fibonacci(-like) sequences refer to any sequences constructed with the addition rule $a_{j+2}=a_{j}+a_{j+1}$, while the regular Fibonacci sequence refers to the particular sequences 1,1,2,3,5,8,13,...) Historical research on pattern formation on plants, tracing back to as early as four hundred years ago, was mostly geometry based. Current studies focus on the activities on the cellular level and study initiation of primordia (the initial undifferentiated form of phylla) as a morphogenesis process cued by some signal. The nature of the signal and the mechanisms governing the distribution of the signal are still under investigation. The two top candidates are the biochemical hormone auxin distribution and the mechanical stresses in the plant surface (tunica). We built a model which takes into consideration the interactions between these mechanisms. In addition, this dissertation explores both analytically and numerically the conditions for the Fibonacci-like patterns to continuously evolve (i.e. as the mean radius of the generative annulus changes over time, the numbers of spirals in the pattern increase or decreases along the same Fibonacci-like sequence), as well as for different types of pattern transitions to occur. The essential condition for the Fibonacci patterns to continuously evolve is that the patterns are formed annulus by annulus on a circular domain and the pattern-forming mechanism is dominated by a quadratic nonlinearity. The predominance of the regular Fibonacci pattern is determined by the pattern transitions at early stages of meristem growth. Furthermore, Fibonacci patterns have self-similar structures across different radii, and there exists a one-to-one mapping between any two Fibonacci-like patterns. The possibility of unifying the previous theory of optimal packing on phyllotaxis and the solutions of current mechanistic partial differential equations is discussed.

Thesis (M.S.)--Rochester Institute of Technology, 2008. / Typescript. Includes bibliographical references (leaf 17).

Dissertação (mestrado profissional) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Matemática, Florianópolis, 2016. / Made available in DSpace on 2016-09-20T04:59:37Z (GMT). No. of bitstreams: 1 339470.pdf: 396622 bytes, checksum: 6674b54533ca1683079c5d8de0c2be85 (MD5) Previous issue date: 2016 / Neste trabalho mostraremos como encontrar uma fórmula para o termo geral da sequência de Fibonacci. Esta fórmula será encontrada de duas maneiras distintas, inicialmente utilizando a teoria de sequências definidas recursivamente e em seguida utilizando como método resultados de álgebra matricial.<br> / Abstract : In this work we show how to find a formula for the general term of the Fibonacci sequence. This formula will be obtained in two distinct ways, initially using the theory of recursively defined sequences and after that using results of matrix algebra.

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, 2017. / Submitted by Gabriela Lima (gabrieladaduch@gmail.com) on 2017-12-04T18:18:20Z No. of bitstreams: 1 2017_GérsicaValescaLimadeFreitas.pdf: 606748 bytes, checksum: 862a9c6c361512e02280e540830d43c9 (MD5) / Approved for entry into archive by Raquel Viana (raquelviana@bce.unb.br) on 2018-01-25T15:39:27Z (GMT) No. of bitstreams: 1 2017_GérsicaValescaLimadeFreitas.pdf: 606748 bytes, checksum: 862a9c6c361512e02280e540830d43c9 (MD5) / Made available in DSpace on 2018-01-25T15:39:27Z (GMT). No. of bitstreams: 1 2017_GérsicaValescaLimadeFreitas.pdf: 606748 bytes, checksum: 862a9c6c361512e02280e540830d43c9 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) e Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). / Os números de Fibonacci possui várias generalizações, entre elas temos a sequência (Fn (k))n que é chamada de sequência de Fibonacci k-generalizada. Observando a identidade F2 n+F2 n+1=F2n+1, Chaves e Marques, em 2014, provaram que a equação Diofantina (Fn (k))2+ (F(k) n+1)2= Fm (k) não possui soluções em inteiros positivos n, m e k, com n > 1 e k ≥ 3. Nesse trabalho, mostramos que a equação Diofantina (Fn (k))2 +(F(k) n+1)2 = Fm (l), não possui solução para 2≤ k < l e n > k + 1. Outra generalização da sequência de Fibonacci s˜ao os coeficientes fibonomiais. Em 2015, Marques e Trojovský provaram que uma condição mais fraca. se p ≡ ± 1 (mod 5), então p † [pa+1 pa] , para todo a ≥ 1.Nesse trabalho, encontramos as classe de resíduos de módulo p, p2, p3 e p4, quando p ≡ ± 1 (mod 5) e sobre uma condição mais fraca. Em particular, provamos que se p é um número primo tal que p ≡ ± 1 (mod 5), então [pa+1 pa] ≡ 1 (mod p). / Regarding the identity F2 n+F2 n+1=F2n+1, Chaves and Marques, in 2014, proved that (Fn (k))2+ (F(k) n+1)2= Fm (k) does not have solution for integers n, m e k, with n > 1 and k ≥ 3. In this work, we show that (Fn (k))2 +(F(k) n+1)2 = Fm (l) does not have solutions for 2≤ k < l and n > k + 1. Another generalization of the Fibonacci sequence are the Fibonomial coe#cients. In 2015, Marques and Trojovský proved that if p ≡ ± 1 (mod 5), then p † [pa+1 pa] for all a ≥ 1. In this work, we also find the residue class of [pa+1 pa] modulo p, p2, p3 e p4, when p ≡ ± 1 (mod 5) under some weak hypothesis. In particular, we proved that if p is a prime number such that p ≡ ± 1 (mod 5), then [pa+1 pa] ≡ 1 (mod p).

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, Programa de Mestrado Profissional em Matemática em Rede Nacional, 2015. / Submitted by Fernanda Alves Mignot (fernandamignot@hotmail.com) on 2015-11-05T19:12:02Z No. of bitstreams: 1 2015_GustavoCandeiaCosta.pdf: 843402 bytes, checksum: dd61c70734d3156b82f3a83934613a57 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2015-11-05T19:33:12Z (GMT) No. of bitstreams: 1 2015_GustavoCandeiaCosta.pdf: 843402 bytes, checksum: dd61c70734d3156b82f3a83934613a57 (MD5) / Made available in DSpace on 2015-11-05T19:33:12Z (GMT). No. of bitstreams: 1 2015_GustavoCandeiaCosta.pdf: 843402 bytes, checksum: dd61c70734d3156b82f3a83934613a57 (MD5) / Seja (Fn)n≥0 a sequência de Fibonacci e z(n) a ordem de aparição nessa sequência definida como o menor k Є N tal que n divide Fk. Nesse trabalho, discutiremos algumas propriedades dessa função. O principal objetivo é provar que existem infinitas soluções para a equação z(n) = z(n + 2) e exibir fórmulas fechadas para z(Fm ± 1). Mas, antes disso, detalharemos propriedades dos números de Fibonacci e números de Lucas. ______________________________________________________________________________________________ ABSTRACT / Let (Fn)n≥0 be the Fibonacci sequence and let z(n) be the order of appearance in this sequence which is defined as the smallest k Є N such that n divides Fk. In this work, we shall discuss some properties of this function. The main goal is to prove the existence of infinitely many solutions to the equation z(n) = z(n + 2) as well as to exhibit closed formulas for z z(Fm ± 1). At first, we shall describe the properties of Fibonacci and Lucas numbers.

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, 2014 / Submitted by Ana Cristina Barbosa da Silva (annabds@hotmail.com) on 2014-12-05T11:31:19Z No. of bitstreams: 1 2014_MarcusViniciusPereira.pdf: 1495143 bytes, checksum: 847eb280919f4cd43cfea39b1e5ac3ce (MD5) / Approved for entry into archive by Guimaraes Jacqueline(jacqueline.guimaraes@bce.unb.br) on 2014-12-05T14:32:22Z (GMT) No. of bitstreams: 1 2014_MarcusViniciusPereira.pdf: 1495143 bytes, checksum: 847eb280919f4cd43cfea39b1e5ac3ce (MD5) / Made available in DSpace on 2014-12-05T14:32:22Z (GMT). No. of bitstreams: 1 2014_MarcusViniciusPereira.pdf: 1495143 bytes, checksum: 847eb280919f4cd43cfea39b1e5ac3ce (MD5) / O objetivo deste texto é realizar um estudo sobre sequências numéricas mostrando exemplos de sequências não comumente estudadas no ensino médio inclusive as decorrentes da solução de determinados problemas. Abordamos também as relações de recorrência, apresentando alguns resultados sobre a resolução de tais recorrências e sugerindo atividades de investigação matemática em sala de aula. _________________________________________________________________________________ ABSTRACT / The aim of this paper is to conduct a study on numerical sequences showing ex-amples of sequences unusually studied in high school including those resulting from the solution of certain problems. We also analyze the recurrence relations, present some re-sults about solving such recurrences and suggest mathematical research activities in the classroom.

Early in the thirteenth century, Leonardo de Pisa, or, Fibonacci, introduced his famous rabbit problem, which may be stated simply as follows: assume that rabbits reproduce at a rate such that one pair is born each month from each pair of adults not less than two months old. If one pair is present initially, and if none die, how many pairs will be present after one year? The solution to the problem gives rise to a sequence {U_n} known as the Classical Fibonacci Sequence. {U_n} is defined by the recurrence relation U_n = U_n-1 + U_n-2, n ≥ 2, U₀ = 0, U₁ = 1 Many properties of this sequence have been derived. A generalized sequence {F_n} can be obtained by retaining the law of recurrence and redefining the first two terms as F₁ = p', F₂ = p' + q' for arbitrary real numbers p' and q'. Moreover, by defining H₁ = p+iq, H₂ = r+is, p,q,r and s real, a complex sequence is determined. Hence, all the properties of the classical sequence can be extended to the complex case. By reducing the classical sequence by a modulus m, many properties of the repeating sequence that results can be derived. The Fibonacci sequence and associated golden ratio occur in communication theory, chemistry, and in nature. / Master of Science