Submitted by Anna Patricia Pachas Manrique (annapamanrique@gmail.com) on 2017-02-23T20:20:56Z No. of bitstreams: 1 20_02 (1).pdf: 1460371 bytes, checksum: e98c8f4713680550a770e8efcc7ffa14 (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2017-08-03T17:52:37Z (GMT) No. of bitstreams: 1 20_02 (1).pdf: 1460371 bytes, checksum: e98c8f4713680550a770e8efcc7ffa14 (MD5) / Made available in DSpace on 2017-08-18T14:34:31Z (GMT). No. of bitstreams: 1 20_02 (1).pdf: 1460371 bytes, checksum: e98c8f4713680550a770e8efcc7ffa14 (MD5) Previous issue date: 2016-08-29 / The speed and comprehensiveness global level with the pathogen has spread in recent years has drawn attention to the importance of the contact’s social network structure. In fact, the topology of the networks in which members of society interact has influenced the dynamics of epidemics. Studies have shown that pathogens when disiparem in scale-free networks have different effects when compared broadcast in random networks, such as the classic models. In these there were epidemic threshold, may somehow the health ministry have a control on the dissipation of diseases by applying certain measures such as vaccines. Already in models in which are considered the networks, specifically the free network scale, the threshold disappears. Thus, the epidemic threshold depends on the topology is required to include within this structure models Because of the importance of these networks, random networks and scalefree have been implemented along the epidemics of propagation models to check the epidemic threshold and the characteristic time, noting that the epidemic threshold disappears / A velocidade e a abrangência a nível mundial com que os agentes patogênicos tem se disseminado nos últimos anos tem chamado a atenção para a importância da estrutura da rede social de contato . De fato, a topologia das redes na qual os membros da sociedade interagem têm influenciado na dinâmica das epidemias.Estudos têm demostrado que os agentes patogênicos ao se dissiparem em redes livres de escala tem efeitos diferentes se comparado quando difundidos em redes aleatórias, como nos modelos clássicos. Nestes existiam limiar de epidemia ,podendo de alguma forma as entidades de saúde ter um controle sobre a dissipação das enfermidades , aplicando certas medidas como as vacinas por exemplo. Já nos modelos nos quais são consideradas as redes , especificamente a rede livre de escala,este limiar desaparece. Desta forma, o limiar de epidemia ao depender da topologia se faz necessário incluir esta estrutura dentro dos modelos epidemiológicos. Devido a importância destas redes , redes aleatórias e principalmente redes livres de escala foram implementadas junto a modelos de propagação de epidemias para verificar o limiar de epidemia e o tempo característico , verificando que o limiar de epidemia desaparece.

Estuda-se o espalhamento de doenças contagiosas utilizando modelos suscetível-infectado-recuperado (SIR) representados por equações diferenciais ordinárias (EDOs) e por autômatos celulares probabilistas (ACPs) conectados por redes aleatórias. Cada indivíduo (célula) do reticulado do ACP sofre a influência de outros, sendo que a probabilidade de ocorrer interação com os mais próximos é maior. Efetuam-se simulações para investigar como a propagação da doença é afetada pela topologia de acoplamento da população. Comparam-se os resultados numéricos obtidos com o modelo baseado em ACPs aleatoriamente conectados com os resultados obtidos com o modelo descrito por EDOs. Conclui-se que considerar a estrutura topológica da população pode dificultar a caracterização da doença, a partir da observação da evolução temporal do número de infectados. Conclui-se também que isolar alguns infectados causa o mesmo efeito do que isolar muitos suscetíveis. Além disso, analisa-se uma estratégia de vacinação com base em teoria dos jogos. Nesse jogo, o governo tenta minimizar os gastos para controlar a epidemia. Como resultado, o governo realiza campanhas quase-periódicas de vacinação. / The spreading of contagious diseases is studied by using susceptible-infected-recovered (SIR) models represented by ordinary differential equations (ODE) and by probabilistic cellular automata (PCA) connected by random networks. Each individual (cell) of the PCA lattice experiences the influence of others, where the probability of occurring interaction with the nearest ones is higher. Simulations for investigating how the disease propagation is affected by the coupling topology of the population are performed. The numerical results obtained with the model based on randomly connected PCA are compared to the results obtained with the model described by ODE. It is concluded that considering the topological structure of the population can pose difficulties for characterizing the disease, from the observation of the time evolution of the number of infected individuals. It is also concluded that isolating a few infected subjects can cause the same effect than isolating many susceptible individuals. Furthermore, a vaccination strategy based on game theory is analyzed. In this game, the government tries to minimize the expenses for controlling the epidemic. As consequence, the government implements quasi-periodic vaccination campaigns.

Made available in DSpace on 2016-03-15T19:37:27Z (GMT). No. of bitstreams: 1 Davi de Oliveira Gerardi.pdf: 2216694 bytes, checksum: 5c92a695124c5b7d9e20de8329020701 (MD5) Previous issue date: 2010-08-02 / SIS (susceptible-infected-susceptible) and SIR (susceptible-infectedremoved) epidemiological models based on probabilistic cellular automaton (PCA) are used in order to simulate the temporal evolution of the number of people infected by dengue in the city of Rio de Janeiro in 2007, and to predict the cases of infection in 2008. In the PCA, three different sizes of lattices and two kinds of neighborhoods are utilized, and each time step of simulation is equivalent to one week of real time. A genetic algorithm (GA) is employed to identify the probabilities of the state transition S→I, in order to reproduce the historical series of 2007 related to this disease propagation. These probabilities depend on the number of infected neighbors. Time-varying and constant probabilities are taken into account. These models based on PCA and GA were able of satisfactorily fitting the data from 2007 and making a good prediction for 2008 (mainly about the total number of cases registered during 2008). / Usam-se modelos epidemiológicos SIS (suscetível-infectado-suscetível) e SIR (suscetível-infectado-removido) baseados em autômato celular probabilista (ACP) a fim de simular a evolução temporal do número de pessoas infectadas por dengue, na cidade do Rio de Janeiro em 2007, e de prever os casos de infecção em 2008. No ACP, utilizam-se reticulados de três tamanhos diferentes e dois tipos de vizinhanças, e cada passo de tempo da simulação equivale a uma semana de tempo real. Emprega-se um algoritmo genético (AG) para identificar os valores das probabilidades da transição de estados S→I, de modo a reproduzir a série histórica de 2007 relacionada à propagação dessa doença. Essas probabilidades dependem do número de vizinhos infectados. Probabilidades variantes e invariantes no tempo são consideradas. Esses modelos baseados em ACP e AG foram capazes de fazer um ajuste satisfatório dos dados de 2007 e de fornecerem uma boa previsão para 2008, (principalmente no que diz respeito ao número total de casos registrados em 2008).

L'objectif de cette thèse est principalement d'appliquer la théorie du contrôle optimal à des problématiques que soulèvent la maladie du diabète et celle de la propagation de la rumeur sur les réseaux sociaux.Pour la première application, à savoir la maladie du diabète, nous développons deux études. Dans une première étude, à un modèle qui examine les diabétiques avec et sans complications, nous associons un problème de contrôle optimal. Nous montrons qu'il n'existe pas de comportement cyclique entre le groupe des diabétiques avec complications et celui des diabétiques sans complications, et que le point d'équilibre associé au problème existe et est un point selle. Dans une seconde étude, nous modifions un modèle de glucose-insuline à temps différé par l'ajout d'actions extérieures avec retard. Puis, pour minimiser la glycémie d'un diabétique, nous les contrôlons séparément puis simultanément, afin d'en donner une caractérisation à l'aide du principe du maximum de Pontryagin.Pour la deuxième application, la problématique de la propagation de la rumeur sur les réseaux sociaux, nous proposons aussi deux approches. Premièrement, nous mettons en place des stratégies optimales, par l'ajout d'actions extérieures sur un modèle d'e-rumeur de type SIR que nous contrôlons séparément puis simultanément, pour minimiser la propagation d'une fausse information. Et, dans une deuxième approche, nous construisons un nouveau modèle d'e-rumeur pour lequel nous étudions les points d'équilibres admissibles en mettant en évidence leurs conditions de stabilité, ainsi que les critères de persistance du modèle. / The aim of this thesis is mainly to apply optimal control theory to problems raised by diabetes disease and the spread of rumors on social networks.For the first application, namely diabetes disease, we develop two studies. In a first one, from a model that examines diabetics with and without complications, we associate an optimal control problem. We show that there is no cyclical behavior between the group of diabetics with complications and the one without complications, and that the associated equilibrium point exists and is a saddle point. In a second study, we modify a model of delayed glucose-insulin by adding external actions with delay. Then, in order to minimize the glycemia of a diabetic, we control them separately and simultaneously in order to give a characterization of the optimal actions with the Pontryagin maximum principle.For the second application, the issue of spreading rumors on social networks, we also give two approaches. First, we introduce some optimal strategies, by adding external actions on a e-rumor model of SIR type that we control separately and simultaneously to minimize the spread of fake news. Then, in a second approach, we build a new e-rumor model for which we study the admissible equilibrium points by highlighting their stability conditions, as well as the criteria of persistence of the model.

Thesis (Ph. D.)--University of South Africa, 2002.

No description available.

Thesis (PhD)-- Stellenbosch University, 2011. / ENGLISH ABSTRACT: This study is a biography of Sir David Pieter de Villiers Graaff, Bt, of Cape Town, who was born in 1859 and died in 1931. It covers his whole life span, from his birth as a poor farm boy in the district of Villiersdorp until his death as one of South Africa’s most innovative businessmen after he also distinguished himself in a political career. As the pioneer of cold storage in South Africa he brought the practice of frozen meat and food to the country at the end of the nineteenth century and in the meat trade he built up one of the biggest business undertakings in the Southern Hemisphere. As mayor of Cape Town at the youthful age of 31 he played a decisive rol in the modernisation of the city. As a member of Genl. Louis Botha’s first Cabinet after Union in 1910, a defining event which laid down the borders of the present Republic of South Africa, he played a sometimes underestimated role in the development of the country and its economy after the tribulations and long-term effects of the Anglo-Boer War. The life of this complex businessman/politician, a Cape Afrikaner who as a bachelor at an advanced age received a hereditary British title and thereafter married the daughter of the dominee of his Dutch Reformed congegation, is also a fascinating example of the difficult choices which Cape Afrikaners in colonial times had to make between loyalty to the British Crown and commitment to the native soil of South Africa. His biography furthermore offers an insight into the role of a top business leader who enters politics, a facet which has received little coverage in South African historial research. By describing the mosaic of his life in the time span in which he was a prominent figure, it was endeavoured to cast more light on the social and cultural context of an epoch-making period, thereby seeking to contribute to a nuanced understanding of the South African past. / AFRIKAANSE OPSOMMING: Hierdie studie is ‘n biografie van sir David Pieter de Villiers Graaff, die baronet van Kaapstad wat in 1859 gebore en in 1931 oorlede is. Dit dek sy hele lewensloop, van sy geboorte-uur as arm plaasseun in die distrik van Villiersdorp totdat hy as een van Suid-Afrika se innoverendste sakemanne gesterf het nadat hy hom ook in ‘n politieke loopbaan onderskei het. As die pionier van koelbewaring in Suid-Afrika het hy teen die einde van die negentiende eeu die verkoeling van vleis en voedsel op groot skaal na die land gebring en in die vleisbedryf een van die grootste sakeondernemings in die Suidelike Halfrond opgebou. As burgemeester van Kaapstad op die jeugdige ouderdom van 31 het hy ‘n deurslaggewende bydrae tot die modernisering van die stad gelewer. As lid van genl. Louis Botha se eerste Kabinet na Uniewording in 1910, ‘n bepalende gebeurtenis waardeur die landsgrense van die huidige Republiek van Suid-Afrika vasgelê is, het hy ‘n soms onderskatte rol in die opgang van die land en die landsekonomie na die beproewinge en langtermyn-gevolge van die Anglo-Boere-oorlog gespeel. Die lewensverhaal van hierdie komplekse sakeleier-politikus, ‘n Kaapse Afrikaner wat as vrygesel op gevorderde leeftyd ‘n erflike Britse titel ontvang het en daarna met die dogter van die leraar van sy NG gemeente getroud is, is boonop ‘n boeiende voorbeeld van die moeilike keuses wat Kaapse Afrikaners in koloniale tye tussen trou aan die Britse Ryk en verankering in die Suid- Afrikaanse bodem moes maak. Sy lewensverhaal bied voorts insig in die rol van ‘n top-sakeman wat tot die aktiewe politiek toetree, ‘n faset wat in die Suid-Afrikaanse geskiedskrywing nog weinig ontgin is. Deur die mosaïek van sy lewe uit te beeld in die tydsgewrig waarin hy ‘n prominente figuur was, is gepoog om ook meer lig op die maatskaplike en kulturele konteks van daardie epogmakende tydperk te werp en sodoende ‘n genuanseerde begrip van die Suid- Afrikaanse verlede te bevorder.

Thesis (PhD)--Stellenbosch University, 2013. / This investigation is aimed at providing a better understanding of William Milton’s influence on society in southern Africa over a period of more than thirty years. In the absence of any previous detailed work, it will serve to demonstrate Milton’s importance in restructuring the administration, formulating policy and imposing social barriers in early Rhodesia – factors that will contribute to the research undertaken by revisionist writers. It will also go some way towards answering Lord Blake’s call to discover exactly what the Administrator did and how he did it. Milton’s experiences at the Cape are seen as being essential to an understanding of the administration he established in Rhodesia. Through examining this link – referred to by historians but not as yet explored in detail – new knowledge will be provided on Rhodesia’s government in the pre-First World War period. The Cape years will offer insight into Milton’s working relationship with Rhodes and his involvement in the latter’s vision of the region’s social form and future. They will also shed light on Milton’s attitude towards people of colour. Cricket and rugby are key themes running through Milton’s life. The study will illuminate much about the creation of South African sport at a time when the public school games ethic was important in the nature of empire. Milton made an enormous but controversial contribution to the playing of the games, club culture, facilities, administration, international competition and who was eligible to represent South Africa.

近年來電腦科技進步、資料庫健全發展，使得處理大量資料的需求增加，因而發展出結合生物醫學與資訊統計兩大領域的生物資訊(Bio-informative)。這個新學門的特色在於資料量及資料變數的龐雜，但過多資料經常干擾資訊的篩選，甚至癱瘓資料分析，因此如何適當地縮減資料(Data Reduction)就變得必要。資料縮減常藉由維度縮減(Dimension Reduction)進行，其中常見的線性維度縮減方法首推主成份分析，屬於非監督式學習(Unsupervised Learning)的一種，而線性的監督式學習(Supervised Learning)方法則有SIR(Sliced Inverse Regression)、SAVE(Sliced Average Variance Estimate)及pHd(Principal Hessian Directions)。非監督式學習的主成份分析，主要在找出少數幾個維度而可以解釋代表自變數的變異程度，而監督式學習的SIR、SAVE及pHd則可以在縮減維度時，同時考量自變數跟應變數之間的關係，而找出可以解釋應變數的維度。 本研究為解決蛋白質質譜儀資料高維度的問題，將應用各種線性維度縮減方法，並分別使用CART(Classification and Regression Tree)、KNN(K-Nearest Neighbor)、SVM(Support Vector Machine)、ANN(Artificial Neural Network)四種分類器，比較各維度縮減方法的分錯率高低，以交叉驗證(Cross Validation)比較維度縮減方法的優劣。研究發現在四種維度縮減方法中，PCA及SIR在各種分類器下都有較為穩定的分錯率，表現較為一致，但SAVE及pHd較不理想。我們也發現在不同的分類器下，PCA跟SIR兩者有不同表現，正確率較高的分類器(SVM與ANN)與PCA結合，而正確率較低的分類器(CART與KNN)與SIR結合，會有較佳的結果。另外，我們也嘗試整合分析(Meta Analysis)，綜合幾種線性維度縮減方法，而提出邊際訓練效果法(Marginal Training Effect Method)與加權整合法(Meta Weighted Method)，其中發現邊際訓練效果法若可以挑選出有效的維度，可以在不同分類器下提高整體模型，而加權整合法則確保在不同分類器下，讓其分類模型具有較為穩定的準確率；並提出相關係數重疊法(Overlap Correlation Method)來解決需要決定維度大小的問題。

An examination of the influence of medieval numerology and number theory upon the works of the Gawain poet, this essay seeks to connect the importance of numbers to the construction of the four poems. By examining such number theories as the Divine Proportion and marriage numbers, as well as Pythagorean number concepts of masculine and feminine numbers, a clear connection between the literature and the number can be found. The poet not only seeks to use numbers to impart important Christian doctrine to his readers in a subconscious way, he also demonstrates an extreme pre-planning of every line and layout of each poem upon the page. Continuing in current critical traditions of examining this manuscript as whole, "Pearl, " "Patience, " "Cleanness, " and "Sir Gawain and the Green Knight" are shown to join together in an interweaving of connectivity through number pattern and the repetition of important numerological concepts.