Thesis (Ph. D.)--University of Texas Health Science Center at Houston, School of Public Health, 2008. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1086. Adviser: Wenyaw Chan. Includes bibliographical references.

We study a family of random walks defined on certain Euclidean lattices that are related to incidence matrices of balanced incomplete block designs. We estimate the return probability of these random walks and use it to determine the asymptotics of the number of balanced incomplete block design matrices. We also consider the problem of collisions of independent simple random walks on graphs. We prove some new results in the collision problem, improve some existing ones, and provide counterexamples to illustrate the complexity of the problem.

This thesis explores the mechanics of governance within several layers of participating firms in the global value chain of the automotive industry, and how new forms of governance shape the development of the Brazilian and Chinese automotive industry. In particular, it examines how the local supply firms from Brazil and China can integrate and upgrade in the globalized automotive industry. By using the global value chain (GVC) framework, the changing inter-firm dynamics between buyer and supplier are analyzed, and their impact on the indigenous supply firms from Brazil and China examined. The results highlight the role of product architecture in defining the value chain governance approach. Through the evolution of product architecture, the lead-firms can globalize their approaches to procurement and supply chain management. Moreover, the globally harmonized products allow the lead-firm to effectively restructure the global supply base to establish a globally harmonized components supply industry by internationalizing the most capable supply firms. Oligopolies along the entire GVC are consciously created by the lead firm. The dynamics of competition between supply firms are changing, as the market for integral components with high asset-specificity are merging into one global market with oligopolistic and oligopsonistic features. While some supply firms from the emerging markets have been able to utilize their business ties with western assembly firms to upgrade within the GVC, most are under pressure to be squeezed out of the GVC through increased global competition. The thesis contributes to the field of development studies by analyzing the prospects for emerging market firms to participate and upgrade in the GVC of western lead-firms. Furthermore, it contributes to the economic theory of governance by presenting evidence of forms of influence outside the realm of supplier-buyer contracts. The thesis further extends the global value chain framework by introduction a fine-tuned approach to ‘power’ as a determinant of governance.

Submitted by HUGO TADEU DELATORRE null (hugomath@uol.com.br) on 2016-02-21T19:31:03Z No. of bitstreams: 1 Aplicação das Cadeias de Markov no Ensino Médio - Hugo Tadeu Delatorre.pdf: 1086069 bytes, checksum: 6440bb8fa43488471cc064085e427f5e (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-02-23T13:42:56Z (GMT) No. of bitstreams: 1 delatorre_ht_me_sjrp.pdf: 1086069 bytes, checksum: 6440bb8fa43488471cc064085e427f5e (MD5) / Made available in DSpace on 2016-02-23T13:42:56Z (GMT). No. of bitstreams: 1 delatorre_ht_me_sjrp.pdf: 1086069 bytes, checksum: 6440bb8fa43488471cc064085e427f5e (MD5) Previous issue date: 2016-01-22 / As Cadeias de Markov são um instrumento poderosíssimo para previsão de eventos do futuro baseado apenas em um passado relativamente recente. São muito utilizadas nas situações mais diversas como na bolsa de valores, na fidelização de clientes, previsão do tempo, dentre outras. O objetivo principal deste trabalho é mostrar, em nível de Ensino Médio algumas interessantes aplicações, bem como estimular os alunos à pesquisa, coleta e processamento de dados, mostrando-nos o quanto a Matemática está presente no cotidiano de cada um deles. / The Markov Chains are a powerful tool for predicting future events based only on a relatively recent past. They are widely used in different situations such as on the stock exchange in customer loyalty, weather, among others. The main objective of this work is to show high school level in some interesting applications, as well as encourage students to research, collecting and processing data, showing us how mathematics is present in the daily life of each one of them.

Increasing the social, economic, and environmental sustainability of food systems while making them productive enough to feed a future global population of 9 billion is one of the most significant challenges facing humanity. Aquaculture is touted as a food system that can make a profound contribution to this challenge, but much more research is needed to understand how it can develop sustainably. In central Bolivia, an aquaculture system is emerging that is generating opportunities for empowerment, food security, and poverty reduction. However, pathways that lead to the capture of these opportunities while avoiding challenges are not well defined. It is also unclear how the trajectory of growth can be supported so that aquaculture in the region can sustainably contribute to rural development. The purpose of this study, therefore, was to determine how rural small-scale aquaculture systems can contribute to food production while also being environmentally, socially, and economically sustainable. To do so, a new holistic value chain analysis that incorporates horizontal linkages (gender, food security, poverty analysis, and socio-political context) was developed and utilized. It included semi-structured interviews with 40 central Bolivian aquaculture producers, 40 farmers who did not produce aquaculture fish, 26 people employed in the aquaculture value chain, and 18 aquaculture system key informants. The study found that aquaculture in central Bolivia tends to have a positive effect on system participants and has a low environmental impact. It also identified improvements that the system could make to improve its productivity and sustainability. Beyond the central Bolivian aquaculture system specifically, the research makes an important and valuable contribution to knowledge by identifying and explaining the linkages between local and regional food systems in the global South, and sustainable development outcomes. This research provides insight for development researchers and practitioners looking to improve the productivity and sustainability of aquaculture systems. This research also improves our understanding of how food system development can generate empowerment, food security, and poverty reduction more broadly. / Graduate

Submitted by Jean Akio Shida Hashioka (jeanhashioka@hotmail.com) on 2018-07-15T18:07:38Z No. of bitstreams: 1 JEAN AKIO SHIDA HASHIOKA - DISSERTAÇÃO.pdf: 1481230 bytes, checksum: 0f68b8e12c0a1f82eeaf421be75f5c17 (MD5) / Approved for entry into archive by Elza Mitiko Sato null (elzasato@ibilce.unesp.br) on 2018-07-17T13:30:41Z (GMT) No. of bitstreams: 1 hashioka_jas_me_sjrp.pdf: 1481230 bytes, checksum: 0f68b8e12c0a1f82eeaf421be75f5c17 (MD5) / Made available in DSpace on 2018-07-17T13:30:41Z (GMT). No. of bitstreams: 1 hashioka_jas_me_sjrp.pdf: 1481230 bytes, checksum: 0f68b8e12c0a1f82eeaf421be75f5c17 (MD5) Previous issue date: 2018-06-15 / Este trabalho consiste em apresentar a abordagem das cadeias de Markov como ferramenta auxiliadora na prática docente da matemática no Ensino Médio, tornando o processo mais tangível à realidade dos alunos. A contextualização dos conteúdos de matrizes, sistemas lineares e probabilidade poderá ser feita com exemplos práticos do cotidiano, considerando o meio social em que vivem os estudantes, resgatando assim o desejo pela aprendizagem e pelas aplicações da matemática. Espera-se desta forma maior receptividade da disciplina por parte dos discentes e, potencialmente, melhor resposta ao aprendizado pretendido. Assim sendo, o estudo aborda, num primeiro momento, a convergência de distribuição de probabilidade de uma cadeia de Markov de dois estados por meio de limites no in nito de uma função de probabilidade. Desta primeira cadeia de Markov de dois estados, é elaborado um roteiro de aula a ser abordado como exemplo a ser trabalhado em sala de aula relacionado às probabilidades de um time de futebol vencer as suas próximas partidas. Prosseguindo, observa-se a aplicabilidade das cadeias de Markov para calcular a distribuição de probabilidades de um jogador estar perdido em diferentes salas de um labirinto para cada tentativa de encontrar a saída. A m de evidenciar outro exemplo de aplicação das cadeias de Markov, há a construção de um modelo de preci cação de ativos com o objetivo de prever os preços de algumas ações de empresas negociadas na BM&FBOVESPA, a bolsa de valores do Brasil. Tal modelo de preci cação de ativos mostrou-se adequado estatisticamente como ferramenta de análise e cálculo dos retornos médios esperados de alguns dos ativos estudados. Por meio do conteúdo apresentado neste estudo, espera-se contribuir com o aprofundamento de alguns recursos e conceitos para a prática docente com aulas sobre cadeias de Markov no Ensino Médio. Esses aspectos direcionam esta pesquisa para um relevante processo de desenvolvimento do raciocínio, senso crítico e tomada de decisões em situações progressivamente mais complexas vividas pelos alunos. / This work presents the Markov chain approach as a useful tool in the teaching practice of mathematics in High School, making the process more tangible to the students' reality. The contextualization of matrix contents, linear systems and probability can be done with practical examples of daily life, considering the social environment in which students live, thus recovering the desire for learning and the applications of mathematics. It is expected in this way more receptivity of the discipline on the part of the students and, potentially, better response to the intended learning. Thus, the study addresses, rst, the convergence of probability distribution of a two-state Markov chain by means of in nite limits of a probability function. From this rst Markov chain of two states, a lesson script is elaborated to be approached as example to be worked in classroom related to the probabilities of a soccer team to win its next matches. Proceeding, we observe the applicability of Markov chains to calculate the probability distribution of a player being lost in di erent rooms of a maze for each attempt to nd the exit. In order to highlight another example of the application of the Markov chains, an asset pricing model is designed to predict the prices of some shares of companies traded on BM&FBOVESPA, the Brazilian stock exchange. Such an asset pricing model proved to be statistically adequate as a tool for analysis and calculation of the expected average returns of some of the assets studied. Through the content presented in this study, it is hoped to contribute with the deepening of some resources and concepts for the teaching practice with classes on Markov chains in High School. These aspects direct this research to a relevant process of development of reasoning, critical sense and decision making in progressively more complex situations experienced by students.

No description available.

Made available in DSpace on 2014-06-11T19:30:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-07Bitstream added on 2014-06-13T18:47:33Z : No. of bitstreams: 1 ribeiro_av_me_bauru.pdf: 3385358 bytes, checksum: 8e2e43e5facbedc0c7e25a21e63fe6ac (MD5) / São calculadas as estruturas eletrônicas de arranjos atômicos periódicos unidimensionais, bidimensionais e tridimensionais, através do método de combinação linear de orbitais atômicos (método tight binding). Esses orbitais correspondem aos átomos isolados das espécies químicas que compõem o arranjo atômico sob investigação. Combinações lineares deles, com coeficientes apropriados, aproximam a forma das funções de onda eletrônicas do arranjo atômico. Nos casos em que a sobreposição dos orbitais é desprezada, a contribuição de cada orbital atômico para função de Bloch é mostrada nas representações gráficas das estruturas de bandas calculadas. Após uma brve apresentação do método tight binding, são calculadas as estruturas de bandas de cadeias lineares de átomos de Carbono que têm um ou dois átomos por célula unitária. Essas cadeias são chamadas de cumuleno e poliino, respectivamente. Dentre os arranjos atômicos bidimensionais de interesse, é calculada a estrutura de bandas do grafeno. Essas energias são comparadas com resultados disponíveis na literatura. Para este material é realizada uma breve discussão sobre as bandas 'pi' provenientes de orbitais 'p IND. z' e sobre como a sobreposição dos orbitais atômicos afeta a forma das bandas. O método também é aplicado na modelagem de cristais tridimensionais. São calculadas as estruturas de bandas doo diamante, Germânio (com estrutura de diamente), Arseneto de Gálio (com estrutura zincblend) e Nitreto de Gálio (com estrutura de wurtzita). Os resultados obtidos são comparados com aqueles reportados por outros autores que usaram métodos ab initio / The eletronic structures of periodic arrangements of atoms in one, two and three dimensions are calculated by a linear combinations of atomic orbitals (tight binding method). Those orbitals correspond to the isolated atoms of the chemical species composing the atomic arrangement under investigation. Suitable linear combinations of such states approximate the shape of the eletronic wave functions of the atomic arrangement. When the overlapping of the atomic orbitals is disregarded, the contribution of each orbital to the Bloch state is displayed in the graphs of the band structures. After a brief description of the tight binding method, the band structures of linear chains of Carbon atoms are calculated. The cases of one and two atoms per unit cell are considered. They correspond to cumulene and polyyne, respectively. Among the two-dimensional atomic arrangements of interest, we focus the calculation of the band structure of graphene. The calculated bands are compared with available results. Some attention is devoted to the 'pi' bands associated to the 'p IND. z' orbitals is presented. The effects of the overlapping of the atomic orbitals are discussed. The method is also applied to model three-dimensional crystels. The band structures of diamong, germanium (with diamond structure), Gallium Arsenide (with zincblende structure) and Gallium Nitride (with wurtzite structure) are obtained. The results are compared with those reported by other authors who applied ab initio methods

Current trends have seen a rise in the frequency and severity of disasters on a global scale, with disasters in recent years having some of the most devastating impacts ever seen on the societies they affect. As a result, there are increasing pressures on the Formal Humanitarian Sector (FHS) and their resources, resulting in a growing need to examine the logistical processes essential to humanitarian operations. Existing research within the humanitarian logistics (HL) domain has highlighted a plethora of challenges relating to the efficient and effective delivery of humanitarian assistance to those affected by disasters. Through a systematic literature review, it was discovered that current research predominantly focuses on the activities of humanitarian organisations (HOs); overlooking the social and logistical capacity already present within affected communities. In order to address the gap left by HO-centric HL research, this investigation approaches the challenges of efficient and effective humanitarian assistance from a novel perspective. Drawing upon the notion of Collaborative Aid Networks (CANs), this research explores the role of communities as drivers of HL processes, and of their own relief and recovery. In a field in which empirical data is lacking, this enquiry utilises a constructivist grounded theory methodology in order to gather empirical insights from post-earthquake Nepal. Interviews and observations were conducted over a period of seven weeks, with data being continuously analysed and refined throughout this process. The findings from this research culminated in the development of a theoretical framework which illustrates the interrelationships between CAN characteristics and their outcomes on HL. This study contributes to the emerging debates concerning community participation in disaster contexts, and provides revelatory insights regarding CANs’ unique attributes and competencies, which enable them to positively impact disaster affected communities. In levying CAN support, the FHS could increase the efficiency and effectiveness of their HL operations, whilst improving collaboration and communication between the FHS and the community; in turn supporting the legitimacy and downward accountability of FHS programmes.

Made available in DSpace on 2014-06-12T15:58:19Z (GMT). No. of bitstreams: 2 arquivo3464_1.pdf: 2672787 bytes, checksum: 9bee33c2153182c2ce64b9027453243a (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Sistemas computacionais estão em constante evolução para satisfazer crescimentos na demanda, ou novas exigências dos usuários. A administração desses sistemas requer decisões que sejam capazes de prover o nível mais alto nas métricas de desempenho e dependabilidade, com mudanças mínimas `a configuração existente. É comum realizar análises de desempenho, confiabilidade, disponibilidade e performabilidade de sistemas através de modelos analíticos, e as cadeias de Markov representam um dos formalismos matemáticos mais utilizados, permitindo estimar algumas métricas de interesse, dado um conjunto de parâmetros de entrada. No entanto, a análise de sensibilidade, quando feita, é executada simplesmente variando o conjunto de parâmetros dentro de suas faixas de valores e resolvendo repetidamente o modelo escolhido. A análise de sensibilidade diferencial permite a quem está modelando encontrar gargalos de uma maneira mais sistemática e eficiente. Este trabalho apresenta uma abordagem automatizada para análise de sensibilidade, e almeja guiar a melhoria de sistemas computacionais. A abordagem proposta é capaz de acelerar o processo de tomada de decisão, no que se refere a optimização de ajustes de hardware e software, além da aquisição e substituição de componentes. Tal metodologia usa as cadeias de Markov como técnica de modelagem formal, e a análise de sensibilidade desses modelos, preenchendo algumas lacunas encontradas na literatura sobre análise de sensibilidade. Por fim, a análise de sensibilidade de alguns sistemas distribuídos selecionados, conduzida neste trabalho, destaca gargalos nestes sistemas e fornece exemplos da acurácia da metodologia proposta, assim como ilustra sua aplicabilidade