Neste trabalho, aplicamos o algoritmo Breadth-First Search para encontrar o tamanho de uma componente conectada no grafo aleatório de Erdos-Rényi. Uma cadeia de Markov é obtida deste procedimento. Apresentamos alguns resultados bem conhecidos sobre o comportamento dessa cadeia de Markov. Combinamos alguns destes resultados para obter uma proposição sobre a probabilidade da componente atingir um determinado tamanho e um resultado de convergência do estado da cadeia neste instante. Posteriormente, aplicamos o teorema de convergência de Darling (2002) a sequência de cadeias de Markov reescaladas e indexadas por N, o número de vértices do grafo, para mostrar que as trajetórias dessas cadeias convergem uniformemente em probabilidade para a solução de uma equação diferencial ordinária. Deste resultado segue a bem conhecida lei fraca dos grandes números para a componente gigante do grafo aleatório de Erdos-Rényi, no caso supercrítico. Além disso, obtemos o limite do fluído para um modelo epidêmico que é uma extensão daquele proposto em Kurtz et al. (2008). / In this work, we apply the Breadth-First Search algorithm to find the size of a connected component of the Erdos-Rényi random graph. A Markov chain is obtained of this procedure. We present some well-known results about the behavior of this Markov chain, and combine some of these results to obtain a proposition about the probability that the component reaches a certain size and a convergence result about the state of the chain at that time. Next, we apply the convergence theorem of Darling (2002) to the sequence of rescaled Markov chains indexed by N, the number of vertices of the graph, to show that the trajectories of these chains converge uniformly in probability to the solution of an ordinary dierential equation. From the latter result follows the well-known weak law of large numbers of the giant component of the Erdos-Renyi random graph, in the supercritical case. Moreover, we obtain the uid limit for an epidemic model which is an extension of that proposed in Kurtz et al. (2008).

The research conducted for this thesis is an exploratory study of migrant workers' experiences in UK food supply chains. This thesis provides an original contribution to criminology by discussing how some food supply chain dynamics result in various exploitative and harmful labour practices against migrant workers. Data consisted of semi-structured interviews conducted with migrant workers in the UK, as well as individual and group interviews with food supply chain stakeholders, including representatives from industry, regulation, and labour movements. This research conceptualises labour exploitation as a continuum, with severe practices including modern slavery on one extreme and 'decent work' on the other. There are a range of practices in-between these two extremes that risk being overlooked, whereby 'routine', banal exploitation is embedded and normalised within legitimate supply chain processes. The argument developed in this thesis is that a stronger emphasis is needed on the harmful consequences of routine, mundane, everyday labour exploitation in order to understand how they can result from legitimate supply chain dynamics. The key contributions of this thesis can be summarised under four themes: developing a more rigorous analysis of 'routine' labour exploitation and harm against migrant workers; understanding how legitimate food supply chain dynamics can facilitate exploitation and harm; explaining how the regulatory framework may unwittingly result in further exploitation and harm to migrant workers; and recognising the complexity of the relationship between migration and labour exploitation. The thesis findings contribute to predominant discussions of labour exploitation that typically focus on severe exploitation such as modern slavery and emphasise rogue individuals or criminal networks as the main perpetrators. The research findings demonstrate that a significant amount of routine labour exploitation and harm remains 'under the radar' in the context of legitimate supply chain practices. Police action and supply chain regulation typically focuses on the most severe labour exploitation, which results in routine exploitation being largely unaddressed. Therefore, labour exploitation has implications for the nature, organisation, and control of harms facilitated by businesses and supply chains. It is important for criminology and society to not disregard routine labour exploitation, as these practices can result in numerous harmful consequences for workers. Since the public profile of labour exploitation continues to grow, a stronger focus is needed on the routine and banal aspects, not just the most severe practices.

The maternal rearing environment (MRE) of an organism can be a key determinant of an organism's host choice decisions, its own fitness, or the fitness of its offspring. Here, it is investigated if the MRE of an organism can influence lower or higher trophic levels. A series of reciprocal cross-over experiments was conducted using pea aphids (Acyrthosiphon pisum), bean (Vicia faba) or pea (Pisum sativum) plants, and an aphid natural enemy, the parasitoid wasp Aphidius ervi, as model organisms. In each experiment, pea aphid offspring experienced either the same or an alternative plant host to that experienced by their mothers. This PhD showed that the MRE of pea aphids and parasitoid wasps was not a main contributory factor of host choice decisions or offspring fitness but influenced mother parasitoid wasp fecundity. Additionally, the MRE of pea aphids influenced the foliar nutrient concentration of pea plants when infested with the aphid's offspring. First, over shorter infestation periods, variation in foliar nitrogen and essential amino acid concentrations of pea leaves could be explained by pea aphid MRE. Over longer infestation periods, variation in foliar nitrogen and essential amino acid concentrations of pea leaves was explained by a combination of pea aphid MRE and aphid genotype. Second, the 13C concentration of pea leaf tissue, an indicator of stomatal aperture and leaf water stress, varied with pea aphid MREs over longer infestation periods. However, stomatal conductance and the expression of abscisic acid-responsive genes did not vary in a manner that was consistent with leaf water stress. Additional components of an organism's maternal rearing conditions are considered, including symbioses, as a more realistic MRE compared with that observed in nature. Taking account of MREs could provide a better understanding of the factors influencing the fitness of many organisms interacting in natural and managed ecosystems.

Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-04-20T15:44:20Z No. of bitstreams: 2 Dissertação - Frederico Rodovalho de Oliveira - 2018.pdf: 2263442 bytes, checksum: cbb8bc9baf7eeb48e475bd0b59f97f64 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-23T11:53:43Z (GMT) No. of bitstreams: 2 Dissertação - Frederico Rodovalho de Oliveira - 2018.pdf: 2263442 bytes, checksum: cbb8bc9baf7eeb48e475bd0b59f97f64 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-23T11:53:43Z (GMT). No. of bitstreams: 2 Dissertação - Frederico Rodovalho de Oliveira - 2018.pdf: 2263442 bytes, checksum: cbb8bc9baf7eeb48e475bd0b59f97f64 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-26 / The onion is a vegetable consumed by a large part of the world population. Brazil occupies an important position on the world stage, ranking ninth among the largest producers. Most of the national production is concentrated in the Southern Region, which accounts for 45% of the onion production in the country. The state of Goiás currently ranks sixth among the largest domestic producers, accounting for 14% of Brazilian production. The literature on the marketing of horticultural products indicates the existence of a concentration process, which is exercised by the wholesale market, but it is also worth mentioning the fact that the retail market influences the productive chain due to the market power of the large supermarket chains. Thus, the objective of this work is to analyze the existence of Asymmetry in Price Transmission (ATP) among the agents of the onion production chain in Goiás. For the conduction of the study it was necessary to use econometric models such as the one developed by Houck 1977). In general terms, the results indicate that 30% of the income from the sale of the onion, are directed to the rural producer, and the rest is divided between the wholesale market and the retailer. In addition, the results show that asymmetry occurs in the speed of transmission of prices among the agents of the onion production chain, with relative advantage to retail over the other productive links. / A cebola é uma hortaliça consumida por grande parcela da população mundial. O Brasil ocupa importante posição no cenário mundial, ficando com a nona posição entre os maiores produtores. A maior parte da produção nacional está concentrada na Região Sul, que é responsável por 45% da produção de cebola no país. O estado de Goiás atualmente ocupa a sexta posição entre os maiores produtores nacionais, respondendo por 14% da produção brasileira. A literatura sobre comercialização de produtos hortifrutigranjeiros indica a existência de um processo de concentração, que é exercido pelo mercado atacadista, mas merece destaque também, o fato de o mercado varejista influenciar a cadeia produtiva, devido ao poder de mercado das grandes redes de supermercados. Dessa forma, o objetivo deste trabalho é analisar a existência de Assimetria na Transmissão de Preços (ATP) entre os agentes da cadeia produtiva da cebola em Goiás. Para a condução do estudo foi necessário o uso de modelos econométricos, como o desenvolvido por Houck (1977). Em termos gerais, os resultados apontam que 30% da renda pela venda da cebola, são direcionados para o produtor rural, e o restante é divido entre o mercado atacadista e o varejista. Além disso, os resultados mostram que ocorre assimetria na velocidade de transmissão de preços entre os agentes da cadeia produtiva da cebola, com vantagem relativa para o varejo sobre os demais elos produtivos.

A todo momento as organizações precisam se adaptar às constantes mudanças do macroambiente. A ampliação da unidade de processamento ou, ainda, o transplante total ou parcial dessa unidade para um outro local é uma das respostas a essas freqüentes alterações. No entanto, sabe-se que a unidade de processamento é apenas um dos elos de uma cadeia produtiva com dependência vital entre os mesmos. Nesse sentido, o remanejamento ou a instalação de uma unidade de processamento num novo local não é apenas um problema de escolha da área para a instalação dessa unidade, também não pode ser analisado desconectado dos demais elos da cadeia produtiva que participam da produção, transformação e distribuição, pois, como mostra a literatura, o bom desenvolvimento de uma cadeia produtiva depende de que várias condições a montante e a jusante se combinem. Assim, o objetivo central deste trabalho é a proposição de um método de análise de viabilidade para a implantação de uma cadeia produtiva num local completamente novo para esta cadeia. O método foi realizado a partir da revisão de autores clássicos sobre o tema, e pretende-se que sirva de ferramenta para outras cadeias produtivas interessadas em projetos dessa natureza. O método contempla as seguintes etapas: (1) Estudo de Mercado, (2) Lições da Cadeia Produtiva, (3) Tamanho e Localização, (4) Produção Agrícola e Produção Industrial, (5) Sistemas de Distribuição, (6) Análise de Investimentos, Custos Operacionais e Receitas, (7) Avaliação Financeira e Macroeconômica, (8) Arranjos Institucionais e Estrutura de Governança, (9) Diferenciação do Produto. O método proposto foi aplicado num estudo para analisar a implantação da citricultura no Pólo Petrolina-Juazeiro, localizado no Vale São Francisco. Pôde-se com essa experiência constatar que o método pode ser utilizado por qualquer cadeia produtiva interessada em analisar novas áreas para se instalar, podendo ser necessário algum ajuste ou adaptação às especificidades da empresa ou do setor. / Being adapted to all the constant changes of the macro environment is a need to all the organizations nowadays. The extension of a processing unit or its partial or total exchange to another place are examples of these common changes. Having a crucial dependency, it is known that the processing unit is one of the links in a productive chain. Considering this fact, for a relocation or installation of a new processing unit in another place, a new area must be chosen and both transformation and distribution, elements of a productive chain, must be considered as well. As it is learned in the literature, a good development of a productive chain depends of different combinations. The main purpose of this work is to suggest a method of viability analysis for the implantation of a productive chain in a new place. The method was used after a severe revision based on expert authors of this subject and intends to help any productive chain which might be interested in the same projects. The method contemplates the following stages: (1) Market Study, (2) Studies of the productive chain, (3) Size and location, (4) Industrial and Agricultural production, (5) Distribution Systems, (6) Analyze of Investments, Operational costs and incomes, (7) Macroeconomic and Financial evaluation, (8) Governance Structures, (9) Product Differentiation. The method was tested and analyzed during the implantation of citriculture in the regions of Petrolina and Juazeiro, localized in the São Francisco Valley. To conclude with, the use of this method reveled that it can be used in any productive chain willing to test new areas to install, however, some adjustments or adaptations may be necessary to attend some specification of the business.

The Fibonacci Numbers are one of the most intriguing sequences in mathematics. I present generalizations of this well known sequence. Using combinatorial proofs, I derive closed form expressions for these generalizations. Then using Markov Chains, I derive a second closed form expression for these numbers which is a generalization of Binet’s formula for Fibonacci Numbers. I expand further and determine the generalization of Binet’s formula for any kth order linear recurrence.

Agriculturalists in Lebanon are exposed to a wide range of vulnerability factors that have direct impacts on farmers’ livelihoods. To evaluate the effects of those factors and the livelihood challenges they breed, this research analyses how two agricultural activities shape farmer livelihood vulnerability, namely urban agriculture and fruit and vegetable value chains. First, I analyze how vulnerability factors influence urban agriculturalist livelihoods and assess if urban agriculture is an adequate solution to lower their livelihood vulnerability. Second, I analyse how various actors partaking in fruit and vegetable value chains are exposed to different vulnerability factors and how this impacts their individual livelihoods. Conceptually, the urban agriculture component of this research builds from the vulnerability framework and sustainable livelihoods approaches scholarships. The agricultural value chain section engages with literatures centered on the vulnerability framework, sustainable livelihoods approaches and value chain analysis. This thesis concludes that the main vulnerability factors associated with urban agriculture relate to physical, financial and human capitals, and that urban agriculture is not an adequate tool to reduce the livelihood vulnerability of urban agriculturalists. I also conclude that social, financial and human capital barriers significantly affect agricultural value chains actors’ livelihoods. Overall, the vulnerability of the different actors is linked to their socioeconomic status, which dictates the amount of human capital they possess, thus their ability to adapt to changing conditions and external stressors. I posit that human capital is key to both urban agriculture and agricultural value chains, as this asset dictates the vulnerability of individual livelihoods and Lebanese agriculturalists’ ability to sustain their livelihoods.

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<p>In some applications polynomials should be evaluated, e.g., polynomial approximation of elementary function and Farrow filter for arbitrary re-sampling. For polynomial evaluation Horner’s scheme uses the minimum amount of hardware resources, but it is sequential. Many algorithms were developed to introduce parallelism in polynomial evaluation. This parallelism is achieved at the cost of hardware, but ensures evaluation in less time.</p><p>This work examines the trade-off between hardware cost and the critical path for different level of parallelism for polynomial evaluation. The trade-offs in generating powers in polynomial evaluation using different building blocks(squarers and multipliers) are also discussed. Wordlength requirements of the polynomial evaluation and the effect of power generating schemes on the timing of operations is also discussed. The area requirements are calculated by using Design Analyzer from Synopsys (tool for logic synthesis) and the GLPK (GNU Linear Programming Kit) is used to calculate the bit requirements.</p>