Visando representar linhas retas digitais, segmentos digitalizados e arcos, cada uma das linhas de pesquisa disponíveis apresenta suas vantagens e aplicações apropriadas. No entanto, considerando as complexidades de cenários do mundo real, o uso dessas representações não é tão popular em situações que requerem modelos flexíveis ou envolvendo interferências espúrias. As tecnologias adaptativas são formalismos da ciência da computação capazes de alterar seu comportamento dinamicamente, sem a interferência de agentes externos, em resposta a estímulos de entrada. Ao serem capazes de responder às mencionadas condições variáveis do ambiente, os dispositivos adaptativos naturalmente tendem a apresentar a flexibilidade requerida para atuarem em cenários dinâmicos. Assim, este trabalho investiga uma alternativa fundamentada no autômato finito adaptativo por meio do dispositivo denominado segmento digitalizado adaptativo, que incorpore o poder expressivo de representar parâmetros desses segmentos. Dentre esses parâmetros destacam-se a capacidade de representar as tolerâncias, a escalabilidade, os erros causados por desvios em ângulo ou em comprimento dos segmentos mencionados, resultando em estruturas mais flexíveis. Considerando que os métodos sintáticos são estruturais, os segmentos digitalizados adaptativos são modelados por conjuntos de regras, partindo-se de primitivas, concebendo-se as funções adaptativas correspondentes para alteração dos estados e de regras de transição. Posteriormente, estruturas mais elaboradas são concebidas relacionadas a arcos digitais pelos quais cadeias (strings) estimulam, em um passo único, autômatos finitos adaptativos que implementam segmentos digitalizados adaptativos. As implementações utilizam uma ferramenta cujo núcleo é um simulador para edição dos arquivos que compõem os autômatos. Consequentemente, o método proposto torna-se uma alternativa relativamente simples e intuitiva comparando-se com as abordagens existentes, apresentando capacidade de aprendizagem, além de ser computacionalmente poderosa. / For the representation of digital straight lines, digitized straight line segments and arcs, each of the available research approaches has its advantages and suitable applications. However, taking into account the complexities of real-world scenarios, the use of these representations is not so popular in situations that require flexible models or involving spurious interferences. Adaptive technologies are computer science formalisms able to change their behavior dynamically, without the interference of external agents, in response to incoming stimuli. By being able to respond to changing environmental conditions, adaptive devices naturally tend to have the required flexibility to work in dynamic scenarios. Thus, the purpose of this study is to investigate an alternative based on adaptive finite automaton through the device called adaptive digitized straight line segment, incorporating the expressive power to represent parameters of these segments. Among these parameters, emphasis is given to the ability to represent tolerances, scalability or errors caused by deviations in angle or length of the mentioned segments, resulting in more flexible structures. Whereas syntactic methods are structural, adaptive digitized straight line segments are modeled by sets of rules, starting from primitives, conceiving the corresponding adaptive functions to amend the set of states and transition rules. Later, more elaborate structures are designed related to digital arcs the corresponding strings of which stimulate, in just a single step, adaptive finite automata that implement adaptive digitized straight line segments. The implementations use a simulator for editing the files that compose the automata. Consequently, the proposed method reveals to be a simple and intuitive alternative capable of learning, besides being computationally powerful.

Nesta tese apresenta-se o desenvolvimento de diversos modelos computacionais de turbinas eólicas equipadas com diferentes tipos de geradores elétricos, com ênfase no gerador de indução duplamente alimentado. Tais modelos foram desenvolvidos para investigar o desempenho de diferentes estratégias de controle, bem como diferentes estratégias do uso do sistema de proteção do conversor AC/DC/AC. Desenvolveu-se adicionalmente um método analítico para investigar a estabilidade de geradores de indução duplamente alimentados durante grandes perturbações na rede elétrica. Tal método foi validado por meio de comparações entre os resultados da aplicação das fórmulas propostas e de simulações, utilizando uma simplificação dos modelos dinâmicos desenvolvidos. Considerando os modelos dinâmicos, os resultados obtidos por simulações mostram que as escolhas adequadas da estratégia de controle e do sistema de proteção permitem maior injeção de potência reativa durante curto-circuitos na rede elétrica. O método analítico proposto apresentou resultados suficientemente precisos para análise da estabilidade frente a grandes perturbações, reduzindo o esforço necessário para realização de simulações dinâmicas sem a necessidade de compra de licenças de programas específicos. / The development of computational models of wind turbines equipped with different electrical machines is presented in this thesis, emphasizing the doubly fed induction generator. Such models were developed to investigate the performance of different control strategies as well as different protection system of the back-to-back converters. Additionally, this thesis present an original analytic method to investigate the stability of doubly fed induction generators during large disturbance on the electric system. The methodology is validated by comparing results from the developed dynamic models to the results from the analytical equations. For the dynamic models, the obtained results by simulations show that the chosen of the appropriate control strategies and the protection system can permit more reactive power injection during short circuits in the network. The proposed analytic method is sufficiently precise to analyze large disturbance stability reducing the necessary effort spending on dynamic simulation without the need of buying a specific license to run the software.

[pt] A motivação para este trabalho é desenvolver equações simples, porém suficientemente precisas, que possam ser usadas para projetos de vigas casteladas submetidas à flexão pura, considerando a contribuição do conjunto mesa-alma na flambagem local do elemento. Métodos energéticos - Quociente Rayleigh - são adotados para determinar a equação da tensão crítica aproximada. Neste método, a energia de deformação e o trabalho externo são calculados assumindo uma forma de deflexão aproximada, cinemática admissível e contínua. Assim, a precisão do resultado depende da qualidade da forma de deflexão adotada. Estas funções de forma foram escolhidas com base nos resultados obtidos a partir de modelos numéricos criados usando o software ABAQUS e verificados com o software GBTUL, considerando para analise a interação completa entre a alma e a mesa. As expressões desenvolvidas foram baseadas em aproximações clássicas de estabilidade de placas, validadas com estudos paramétricos realizados com os softwares ABAQUS e GBTUL. Os resultados indicaram que a equação proposta pode efetivamente calcular a tensão crítica relativa a instabilidade local de vigas casteladas. A expressão validada e os limites associados são destinados a ser gerais dentro dos limites típicos das aplicações práticas. / [en] The motivation for this work is to develop a simple yet sufficiently accurate equation that can be used in the design of castellated beams subjected to pure bending, considering the contribution of the web-flange coupling effect in the local buckling. To accomplish this, an energy method - Rayleigh quotient - is adopted to determine the approximate critical stress equation. In this method, the strain energy and the potential work are calculated for an assumed approximate and kinematically admissible continuous deflected shape. Thus, the accuracy of the result is dependent on the quality of the assumed buckled shape. These shape functions were chosen based on the results obtained from numerical models created using ABAQUS software and verified with GBTUL, considering full interaction between web and flange. The developed closed-form expressions were based on classical plate stability approximations, validated with parametric studies performed using ABAQUS and GBTUL. The results indicate that the proposed equation can effectively calculate the critical stress of castellated beams due to local instability. The validated expression and its associated limits are intended to be general within the typical limits of practical applications.

Ao final desta pesquisa deseja-se que haja uma metodologia eficiente, cuja finalidade será auxiliar o usuário na transformação de modelos matemáticos e computacionais codificados para computadores sequenciais, em modelos paralelos otimizados para executarem em microcomputadores pessoais modernos, constituídos de CPU com múltiplos núcleos ou de híbridos (CPU + GPGPU) integrados no mesmo chip, com ou sem processadores gráficos (GPGPU) densamente paralelos instalados, mantendo a qualidade de seus resultados originais, com respeito à sua precisão numérica, mas com uma diminuição considerável no tempo de processamento. A emergência, em meados da década 2000, dessas novas arquiteturas de hardware elevou a capacidade de processamento dos microcomputadores pessoais aos patamares dos computadores de grande porte de apenas alguns anos atrás. Este trabalho de pesquisa apresenta duas metodologias, onde a primeira metodologia é composta de três partes e a segunda de duas partes. Somente a terceira parte da primeira metodologia é dependente de tecnologias de hardware. / At the end of this research project, an efficient methodology is expected with the purpose of assisting users in the processing of mathematical and computer models coded for sequential computers in parallel models that are optimized to run on modern personal computers, consisting of a CPU with multiple or hybrid (CPU + GPGPU) cores integrated into the same chip, with or without massively parallel graphics processors (GPGPU) installed. This will ensure the original quality of the results with respect to numerical accuracy, but with a considerable reduction in processing time. The emergence of these new hardware architectures in the mid-2000s increased the processing power of personal computers to the levels of mainframe computers from just a few years previously. This research work presents two methodologies, where the first methodology is composed of three parts and the second methodology is composed of two parts. Only the third part of the first methodology is dependent on hardware technologies.

Sabe-se que na Engenharia há uma larga utilização de uma gama de materiais (concreto, aço, compósitos, solos etc.), os quais, de forma prática são analisados macroscopicamente naquilo que diz respeito a diversos fatores que influem no seu comportamento, como por exemplo, resistência, módulo de elasticidade, rigidez, dentre outras características. No entanto, estes materiais, em sua maioria heterogêneos, possuem tais comportamentos intrinsicamente relacionados à sua estrutura microscópica, a qual nos mostra que um material é o resultado de uma grande combinação de elementos dentro de sua composição, os quais irão reger tais propriedades. Os materiais podem ser estudados em diversas escalas, a qual dependerá do nível de detalhamento a ser atingido, de tal modo que a mesma pode variar desde o meio particulado até seu meio atômico. Uma das principais vantagens dos modelos multi-escala é a visualização, por parte do analista, das interações entre os constituintes do compósito, o que permite um melhor entendimento do comportamento do material e dos fenômenos de deterioração que ocorrem nas escalas menores e que determinam o comportamento da estrutura na escala maior. O objetivo do presente trabalho é fornecer uma revisão da aplicação de tais modelos, bem como estudar tais elementos diferenciais do material, em sua individualidade (como um meio contínuo), para então, através de um volume representativo, determinar as propriedades do material heterogêneo através de um modelo, representando assim o comportamento do conjunto de tais elementos, de tal modo a se tornar possível a avaliação dos impactos de eventuais mudanças em cada elemento no comportamento do material. / It is known that in Engineering there is a wide use of a range of materials (concrete, steel, composites, soils, etc.), which are practically analyzed macroscopically with respect to several factors that influence their behavior, such as for example, strength, modulus of elasticity, rigidity, among other characteristics. However, these materials, mostly heterogeneous, possess such behaviors intrinsically related to their microscopic structure, which shows us that a material is the result of a great combination of elements within its composition, which will govern such properties. The materials can be studied at various scales, which will depend on the level of detail being reached, such that it can vary from the particulate medium to its atomic medium. One of the main advantages of multi-scale models is the analyst\'s visualization of the interactions between the constituents of the composite, which allows a better understanding of the behavior of the material and of the deterioration phenomena occurring in the smaller scales that determine the behavior on the larger scale. The objective of the present work is to provide a review of the application of such models, as well as to study such differential elements of the material, in their individuality (as a continuous medium), to then, through a representative volume, determine the properties of the heterogeneous material through of a model, thus representing the behavior of the set of such elements, so as to make possible the evaluation of the impacts of eventual changes in each element in the behavior of the material.

A recurring theme in the cognitive development literature is the notion that people restructure their task knowledge as they develop increasingly sophisticated strategies. A large body of empirical literature spanning several domains suggests that in some cases, the process of knowledge restructuring is best characterized by a process of sequentially replacing old strategies with newer ones. In other cases, restructuring appears to be better characterized as a process involving changes in the way partial knowledge elements are selectively applied to a task. Critically, the former, but not the latter position, suggests that it may be quite difficult for people to revert to using an old strategy after restructuring has already occurred. The three experiments reported herein suggest that knowledge restructuring observed in experimental settings is aptly characterized by a process of strategy retention. Specifically, people are shown to readily revert to using an old categorization strategy even after demonstrably having restructured their knowledge, suggesting that knowledge is best conceptualized as having a heterogeneous structure. Formal modeling further supports this interpretation of the empirical results, and highlights the important role of selective attention in determining the manifest response strategy. The implications of these findings are discussed in terms of an overarching mixture-of-experts framework of knowledge representation.

In bulk-heterojunction solar cells, device performance is influenced by both the intrinsic properties of the individual components - typically conjugated polymers and fullerene derivatives - and how they assemble and interact at their interface. The ability of fullerene to intercalate within the side-chains of a conjugated polymer can significantly affect the microstructure and overall device performance. Here, a series of computational chemistry approaches are applied to investigate the relationships between structure and property in intercalated polymer:fullerene blend. Using a combination of molecular mechanics (MM) calculation and simulations of 2D grazing incidence X-ray diffraction (GIXD) patterns, we have determined the molecular packing configuration of poly (2,5-bis (3-tetradecyl thiophene-2-yl) thieno[3,2-b]thiophene) (PBTTT-C₁₄) and a blend of PBTTT-C₁₄ and [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM). Based on the confirmed packing structures, the electronic properties and morphological disorder were examined using density functional theory (DFT) and molecular dynamics (MD) calculations, respectively; we also investigated the intermolecular interaction energies behind the structure formation. Finally, we examined the vibrational, redox, and optical properties of the pristine polymer and a series of fullerene derivatives to understand the characteristic modes related to the various charged states of the systems.

本研究以Chen-Chie（Chen and Chie, 2007）所設計的代理人基模型，探討所得分配對彩券銷售額的影響。這篇論文考量了兩種彩券參與函數，一種是採用模糊推論的方法來呈現代理人購買彩券的決定，在此方式下，並未將可能中奬的期望效果納入。另一種則是以預期效用理論為主軸，並且加入主觀認知的中獎機率。除了彩券參與度外，根據Chen and Chie (2007)的設計，還考慮到兩個購買彩券經驗的觀點，分別是自我意識選號及個體間的獨立性。模型中代理人參數並未固定，取而代之的，是讓代理人具有自動產生參數的能力，所有行為的參數是以遺傳演算法取得其適應性。當代理人進行遺傳演算（社會學習）時，代理人對策略的學習會依照區間的設定，進一步作區域性社會學習及全域社會學習。本論文彙集了上述設計，提供了四種彩券市場行為模型，配合不同的所得分配進行模擬，並且利用統計檢定比較其統計量的變化，分析所得分配對彩券銷售額的影響。 / This study addresses the impact of income distribution on lottery sales using an agent-based modeling approach, specifically, the Chen-Chie model (Chen and Chie, 2007). Two kinds of lottery participation function are considered in this thesis. One is more heuristic and does not require agents’ expectations of the odds. In this case, we use the fuzzy inference system to represent agents’ heuristics. The other explicitly takes agents’ expectations of the odds into account, and a formal expected utility maximization approach is taken. In addition to lottery participation, following Chen and Chie (2007), we also consider two additional empirical aspects of lottery plays, namely, conscious selection and state-dependent utilities. The parameters of agents are not fixed; instead, they are autonomous and all behavioral parameters are adaptive via genetic algorithms. While the population genetic algorithms (social learning) are applied, an idea of nearest neighbors learning is used to further distinguish the global social learning from the local social learning. These setups together give us four behavioral models of lottery markets. We then simulate each of these four markets with different income distribution, and then compare their statistic behavior with statistical test to examine the overall effect of income distribution to lottery sales.

Kinetic studies determining the second order rate constants for the monoepoxidation of cyclic dienes, 1,3-cyclohexadiene and 1,3-cyclooctadiene, and the epoxidation of cis-/trans-2-hexenes by dimethyldioxirane (DMDO) were carried out using UV methodology. Consistent with published results, the kinetics of cis-/trans-2-hexenes by DMDO showed greater reactivity of the cis-isomer compared to that of the trans-compound. Molecular modeling studies for the epoxidation of a series of cis-/trans-alkenes, by DMDO were carried out using the DFT approach. The mechanism of epoxidation by DMDO was modeled by determining the transition state geometry and calculating the electronic activation energies and relative reactivities. The calculations were consistent with a concerted, electrophilic, exothermic process with a spiro-transition state for all cases. Kinetic studies for the monoepoxidation of the cyclic dienes showed a greater reactivity for 1,3-cyclohexadiene compared to that for 1,3-cyclooctadiene. The DFT method was employed to successfully model the transition state for the monoepoxidation of the cyclic dienes by DMDO and successfully predict the relative reactivities. Student misconceptions, at the high school and/or middle school level involving energy changes and chemical reactions have been prevalently noted in literature (by ACS and AAAS). Two examples of these misconceptions are: 1) heat is always needed to initiate a chemical reaction and 2) all chemical reactions create or destroy energy. In order to address these types of misconceptions, an educational module detailing the influence of energy changes on chemical reactions has been developed in conjunction with the Bio-bus program for middle and high school students. Visual aids and hands-on activities were developed in the module to potentially help students overcome/deal with the common misconceptions. Surveys were designed to access the situations (determine the extent of the misconceptions) and the effectiveness of the educational module, before and immediately after the module and one-month later to determine retention. The educational module has been presented to approximately 100 high school students from underrepresented communities. Pre-survey data confirmed the presence of the common misconceptions reported in the literature. Data from the post-survey indicated the new instructional module enhanced the student’s interest of science and expanded their content knowledge and laboratory skills. The post-survey data (immediately following the module) showed a significant difference in two out of five misconceptions when compared to the pre-survey data. However, this significance decreased when the 1-month post-survey data were compared to the pre-survey data.

In this thesis, we study two fundamental problems that arise in the modeling of stochastic systems: (i) Validation of stochastic models against behavioral specifications such as temporal logics, and (ii) Discovery of kinetic parameters of stochastic biochemical models from behavioral specifications. We present a new Bayesian algorithm for Statistical Model Checking of stochastic systems based on a sequential version of Jeffreys’ Bayes Factor test. We argue that the Bayesian approach is more suited for application do- mains like systems biology modeling, where distributions on nuisance parameters and priors may be known. We prove that our Bayesian Statistical Model Checking algorithm terminates for a large subclass of prior probabilities. We also characterize the Type I/II errors associated with our algorithm. We experimentally demonstrate that this algorithm is suitable for the analysis of complex biochemical models like those written in the BioNetGen language. We then argue that i.i.d. sampling based Statistical Model Checking algorithms are not an effective way to study rare behaviors of stochastic models and present another Bayesian Statistical Model Checking algorithm that can incorporate non-i.i.d. sampling strategies. We also present algorithms for synthesis of chemical kinetic parameters of stochastic biochemical models from high level behavioral specifications. We consider the setting where a modeler knows facts that must hold on the stochastic model but is not confident about some of the kinetic parameters in her model. We suggest algorithms for discovering these kinetic parameters from facts stated in appropriate formal probabilistic specification languages. Our algorithms are based on our theoretical results characterizing the probability of a specification being true on a stochastic biochemical model. We have applied this algorithm to discover kinetic parameters for biochemical models with as many as six unknown parameters.