Orientadores: Alberto Vazquez Saa, Marcus Aloizio Martinez de Aguiar / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-28T09:56:07Z (GMT). No. of bitstreams: 1 Depetri_GabrielaIunes_D.pdf: 7529104 bytes, checksum: 4925754e8306e25b65371018747949bf (MD5) Previous issue date: 2015 / Resumo: Nesta tese estudamos, através dos métodos de Melnikov, o comportamento de dois sistemas dinâmicos que são exemplos paradigmáticos de integrabilidade em Mecânica Clássica, quando sujeitos a perturbações: (i) o pêndulo plano simples, no caso em que o pivô oscila harmonicamente ao longo de um eixo inclinado em relação à direção vertical; e (ii) o problema de Kepler, no caso em que a massa do corpo que gera o campo gravitacional possui momento de quadrupolo. Para o pêndulo simples parametricamente excitado ao longo de uma direção inclinada, analisamos a ocorrência de caos homoclínico, e também de oscilações subharmônicas, com o objetivo de comparar os nossos resultados com aqueles conhecidos para o caso em que a excitação ocorre ao longo da direção vertical. Verificamos que o critério para a ocorrência de caos homoclínico é numericamente muito próximo em ambos os casos, mas em relação à ocorrência de soluções oscilatórias subharmônicas notamos uma diferença relevante devido à quebra de simetria nas equações do movimento do sistema: enquanto para o caso vertical a condição de Melnikov garante apenas a existência de oscilações subharmônicas de ordem par, nada se podendo afirmar em relação às subharmônicas de ordem ímpar, para o caso inclinado ela garante a ocorrência de todo o espectro de ressonâncias. Sabemos que apesar de alguns autores reportarem a ocorrência de oscilações subharmônicas de ordem ímpar no caso vertical, estas são muito raras e difíceis de ser encontradas, ao contrário do que acontece com as oscilações subharmônicas de ordem par. Entretanto, neste trabalho mostramos, através de simulações numéricas e dados experimentais, que no caso inclinado elas podem ser encontradas trivialmente em regiões de ressonância, provavelmente porque as bacias de atração dessas órbitas são de natureza diferente em cada caso. Os dados experimentais apresentados nesta tese foram tomados no Laboratório de Fenômenos Não-Lineares (LFNL) do Instituto de Física da Universidade de São Paulo (IFUSP), em colaboração com o Prof. Dr. José Carlos Sartorelli. Para o problema de Kepler, as inomogeneidades na distribuição da massa do corpo que gera o campo gravitacional são descritas através de expansão multipolar. Sabemos o termo de dipolo mantém o sistema integrável. O termo de quadrupolo, por sua vez, pode provocar a ocorrência de caos no sistema. Em um trabalho de 2001, Géron e Letelier afirmam, baseados em simulações numéricas, que no caso em que a perturbação é oblata, o sistema é integrável, enquanto se a perturbação é prolata, o sistema pode apresentar caos. Entretanto, em um trabalho mais recente, Letelier it et al mostram, também numericamente, que ambos os casos podem apresentar trajetórias caóticas. Com o nosso trabalho, resolvemos esta inconsistência na literatura, determinando que a ocorrência de caos de fato não depende do tipo da deformação. Nosso resultado está de acordo com o caso mais geral estudado na literatura / Abstract: In this PhD thesis we study, through the Melnikov methods, the behaviour of two dynamical systems that are paradigms of integrability in Classical Dynamics, when subject to perturbations: (i) the planar simple pendulum, in the case that the pivot oscillates harmonically along a tilted direction; and (ii) the Kepler problem, in the case that the mass of the body generating the gravitational field is not homogeneous, but instead presents a quadrupole moment term. To the simple pendulum parametrically excited along a tilted direction, we analyze the occurence of homoclinic chaos, and also of subharmonic oscillatory solutions, willing to compare our results with those already known in the literature in the case the excitation is along the vertical direction. We verified the criterium to the occurence of homoclinic chaos is numerically very close in both cases, but considering the occurence of subharmonic oscillatory orbits we noted an important difference due to the symmetry breaking of the equations of motion describing the system: while in the vertical case the Melnikov conditions can only assure the occurence of even subharmonic oscillations (nothing can be said about the odd subharmonic oscillating solutions), in the tilted case it guarantees the occurence of all subharmonic oscillations. Still some authors report the occurence of odd subharmonic oscillations in the vertical case, unlike the even oscillatory orbits, those are very rare and hard to find. In this work we show, through numeric simulations and experimental data, that in the tilted case they can be easily found in resonance regions, probably because their basins of attraction have different characteristics in both cases. The experimental data presented in this thesis were taken at the Laboratory of Nonlinear Phenomena (LFNL) at the Physics Institute of the University of São Paulo (IFUSP), in collaboration with Prof. Dr. José Carlos Sartorelli. To the Kepler problem, the inhomogeneities in the mass distribution of the heavy body generating the gravitational field are described through multipolar expansion. We know the dipole term keeps the integrability of the system. The quadrupole term, instead, can lead to the occurence of chaotic orbits in the system. In 2001, Géron and Letelier, based on numeric simulations, assert that the system is integrable if the perturbation is of oblate type, but chaotic if it is of prolate type. However, in a more recent work, Letelier et al show, also via numeric computation, that both cases can present chaotic trajectories. We solve this inconsistency in the literature by determining that the occurence of chaos in fact does not depend on the deformation type. Our results agree with the more general case studied in the literature / Doutorado / Física / Doutora em Ciências / 141762/2011-0 / CNPQ

The dynamics of demand responsive ride pooling (DRRP) systems is considered in a mean-field framework. The relevant dimensionless quantities determining the performance and viability of the system are identified. In the presence of an already established dominant market participant with comparable service quality (like, e.g., the private car), the mutual interaction of the actors (i.e., the customers sharing rides) by virtue of the route assignment algorithm gives rise to a discontinuous transition between two strongly different modes of operation. One of them represents the typical (unfavorable) performance of current ride pooling systems, while the other represents a new mode of operation in which virtually all customers use DRRP.

No description available.

This thesis examines data and theory about how the system of law (SL) operates and evolves: it contrasts data from social workers and attorneys working in the juvenile dependency court with theories about how individuals and social systems evolve. The analysis is based on research conducted in San Diego and revolves around a theory about human development, or the "individual as a system" (HD), and a theory about social systems, such as the autopoietic theory of law and its self-reproducing system (LA). It is suggested that together, the theories of HD+LA help to examine how professionals and law operate and evolve in the legal system. Overall, the thesis rejects the autopoietic systems theory that law reproduces itself, by itself. Instead, analysis in this study supports the finding that law is defined and operates through a dialectic of the individual and the social (or the organic and the mechanistic respectively) such that each gives rise to the other. On the basis of this system connection, aspects from systems theory about legal autopoiesis are integrated into concepts from constructive-developmental theory (HDLA), thus providing a new framework through which to examine how law and its system functions. The new framework is built around an equation that emerged some time after data analysis and theoretical development: SL=HDLA+DSA . The equation states that: The evolution of the system of law involves processes of human development and to some but a much lesser degree, the autopoietic nature of law. The extent of this evolution is best determined by analyzing data from a court setting. The dialectical relationship between individual and social influences in the evolution of law is facilitated by the accumulation of social action � such as activity from media and advocacy groups � and the individual meaning that professionals make about this action, which in turn has an influence on the formal and informal operations that they perform when operating law. The nature of these interacting dynamics will be shown through two interconnected tools of analysis: one is a typology of individual, professional and system self-concepts; the typology helps to show how a cycle of system change (human development giving rise to legal change and vice versa) occurs in the court; the other is the operative structure (or culture) of systems for law and social work in child abuse cases � which unite in court operations. These two interconnected tools help to show how the court operates and how social action (SA) for change contributes to professional and system change in the evolution of law.

This thesis examines data and theory about how the system of law (SL) operates and evolves: it contrasts data from social workers and attorneys working in the juvenile dependency court with theories about how individuals and social systems evolve. The analysis is based on research conducted in San Diego and revolves around a theory about human development, or the "individual as a system" (HD), and a theory about social systems, such as the autopoietic theory of law and its self-reproducing system (LA). It is suggested that together, the theories of HD+LA help to examine how professionals and law operate and evolve in the legal system. Overall, the thesis rejects the autopoietic systems theory that law reproduces itself, by itself. Instead, analysis in this study supports the finding that law is defined and operates through a dialectic of the individual and the social (or the organic and the mechanistic respectively) such that each gives rise to the other. On the basis of this system connection, aspects from systems theory about legal autopoiesis are integrated into concepts from constructive-developmental theory (HDLA), thus providing a new framework through which to examine how law and its system functions. The new framework is built around an equation that emerged some time after data analysis and theoretical development: SL=HDLA+DSA . The equation states that: The evolution of the system of law involves processes of human development and to some but a much lesser degree, the autopoietic nature of law. The extent of this evolution is best determined by analyzing data from a court setting. The dialectical relationship between individual and social influences in the evolution of law is facilitated by the accumulation of social action � such as activity from media and advocacy groups � and the individual meaning that professionals make about this action, which in turn has an influence on the formal and informal operations that they perform when operating law. The nature of these interacting dynamics will be shown through two interconnected tools of analysis: one is a typology of individual, professional and system self-concepts; the typology helps to show how a cycle of system change (human development giving rise to legal change and vice versa) occurs in the court; the other is the operative structure (or culture) of systems for law and social work in child abuse cases � which unite in court operations. These two interconnected tools help to show how the court operates and how social action (SA) for change contributes to professional and system change in the evolution of law.

L'épilepsie est l’un des désordres neurologiques les plus courants; environ 1% de la population mondiale en est atteinte. Elle affecte le fonctionnement des neurones qui s'exprime par une survenue de décharges rapides, appelées crises.Les crises peuvent parfois résister aux médicaments antiépileptiques. Cet état de crise, nommé refractory status epilepticus (RSE), se définit par une survenue des décharges de façon continue, qui sont difficiles à arrêter. Malheureusement, un patient en état RSE risque même de mourir.Le dysfonctionnement des neurones peut parfois se propager lentement vers une dépression corticale envahissante, qui se caractérise par une dépolarisation lente des neurones entraînant une baisse transitoire de l’activité cérébrale.Les mécanismes qui initient ces activités pathologiques restent encore mal connus. Mettant en œuvre une approche mathématique, nous présentons une analyse qualitative d’un modèle dit Epileptor, qui reproduit l’activité épileptique, et décrivons l’évolution temporelle de la crise jusqu’au moment où la personne revient à la normale. La transition vers l’état normal est interprétée comme une bifurcation. Nous démontrons qu’il en existe plusieurs types en variant certains paramètres du modèle, permettant ainsi de classer les crises.Une caractérisation de ces activités est nécessaire pour s’en échapper. Pour ce faire, nous explorons un espace des paramètres permettant de conclure que ces activités coexistent dans le cerveau et surviennent de plusieurs façons. Cet espace des paramètres propose plusieurs voies, qui sont validées expérimentalement, pour éviter ces activités pathologiques et retourner à la normale, d’où son importance. / Epilepsy is one of the most common serious neurological disorders affecting about 1% of the population in the world. It is a condition of the nervous system in which neuronal populations manifest as abnormal excessive discharges, called seizures.On rare occasions, a seizure follows another in a series without recovery, and does not respondto antiepileptic drugs. This state of continuous seizure activity is called refractory status epilepticus, which are difficult to treat. Patients suffering from this state are unfortunately at an increased risk of death.The neuronal dysfunction can sometimes spread slowly towards a spreading depression, which corresponds to a slowly propagating depolarization wave (or depolarization block DB) in neuronal networks, followed by a shut down of brain activity.The mechanisms underlying the genesis of these activities remain unknown. Using a mathematical approach, we present a qualitative analysis of a so-called Epileptor model, which generate epileptic dynamics, and describe how seizures evolve toward termination. The transition to the normal state occurs through a bifurcation. We demonstrate that many types of the bifurcation exist, depending on the values of some parameters. As a consequence, we can classify seizures.To escape from these activities, a characterization is going to be necessary. To this, we explore a parameter space of the model which demonstrate that these activities coexist in the brain, and under some ways. In addition, the parameter space can provide pathways to switch between these activities. Interestingly, we could propose how to return to the ’normal’ brain activity.

Orientador: Alberto Luiz Serpa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-10T21:19:29Z (GMT). No. of bitstreams: 1 Pereira_DanielAugusto_M.pdf: 6268866 bytes, checksum: 3faebe29f9ec8e8f665d11ac095420f8 (MD5) Previous issue date: 2008 / Resumo: Esta dissertação aborda a aplicação de técnicas modernas de controle de sistemas dinâmicosao problema de detecção de falhas. Duas diferentes abordagens de detecção são utilizadas: estimação da falha e geração de resíduo. Tanto na estimação de falha quanto na geração de resíduo é formulado um problema H1 cujo objetivo é encontrar um filtro que garanta robustez a distúrbios.No caso da geração de resíduos, o índice H- é utilizado como critério de desempenho adicional para garantir a sensibilidade à falha e é transformado em um critério H1. O projeto H1 é abordado sob o ponto de vista de desigualdades matriciais lineares. Falhas e distúrbios devem apresentar comportamento em freqüência distintos para que os filtros consigam separar os efeitos dos mesmos. Para garantir o desempenho nas regiões em freqüência de interesse são utilizados filtros de ponderação. Em contraposição a essa abordagem, os resultados recentes da literatura sobre o lema generalizado de Kalman-Yakubovi?c-Popov e o controle H1 restrito na freqüência também são usados como ferramentas de projeto independentes de filtros de ponderação. Os métodos sãocomparados usando modelos de simulação e experimentos no âmbito de estruturas flexíveis / Abstract: This dissertation adresses the application of modern techniques from control of dynamicsystems to the problem of fault detection. Two different approaches are used: fault estimation and residual generation. Both fault estimation and residual generation are formulated as an H1 problem whose objective is to find a filter ensuring robustness to disturbance. In the case of residual generation, theH- index is used as an additional performance criterion to ensure fault sensitiveness and is transformed into an H1 criterion. The H1 design is treated from the point of view of linear matrix inequalities. Faults and disturbances must have distinct frequency distributions so the filter is able to separate them. Weighting functions are used to guarantee performance at the frequency region of interest. In contrast with this approach, recent results from literature on the generalisedKalman-Yakubovi?c-Popov lemma and frequency restricted H1 control are also used as design methods whose application is independent of weighting functions. All methods are compared using simple simulation models and experiments with flexible / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Orientador: Alberto Luiz Serpa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-11T04:04:36Z (GMT). No. of bitstreams: 1 Mazoni_AlyssonFernandes_M.pdf: 2883879 bytes, checksum: a514d74c83605535d0c2eaf4a060356f (MD5) Previous issue date: 2008 / Resumo: Esta dissertação aborda técnicas modernas de controle robusto H8 para sistemas dinâmicos lineares. Com isso pretende-se dizer que são usados como ferramentas matemáticas os resultados da teoria de controle de sistemas lineares para o caso com incertezas de vários tipos admitidas sobre o modelo. Os modelos são primariamente estruturas flexíveis e os métodos de projeto são implementados usando exclusivamente a solução de problemas sujeitos a desigualdades matriciais lineares. São abordadas as incertezas paramétrica, dinâmica e politópica com o objetivo de apresentar métodos matemáticos de projeto de controladores para os sistemas incertos. Para o caso de incerteza dinâmica, apresenta-se a técnica de filtros de ponderação. Em contraposição a essa abordagem, os resultados recentes da literatura sobre o lema generalizado de Kalman-Yakubovi?c-Popov e o H8 restrito na freqüência também são usados como métodos de controle independentes de filtros de ponderação. Os métodos são comparados usando modelos de simulação e experimentos no âmbito de estruturas flexíveis. Palavras-chave: Teoria dos sistemas dinâmicos, Programação Convexa, Sistema de controle por realimentação / Abstract: This dissertation deals with modern techniques from the Robust H8 Control of Linear Dynamic Systems. By this it is meant that the results from linear control systems theory are used as mathemathical tools when considering several kinds of uncertainty on the models. These models are mostly of flexible structures and the design methods are implemented using solely the solution of problems subjected to linear matrix inequalities. The types of uncertainty approached are: parametric, dynamic and polytopic; this is done aiming to present mathematical design methods for the uncertain systems considered. When dealing with dynamic uncertainty, the weighting functions are introduced. In contrast with this approach, recent results from literature on the generalised Kalman-Yakubovi?c-Popov lemma and frequency restricted H8 are also used as control design methods whose application is independent of weighting functions. All methods are compared using simple simulation models and experiments with flexible structures . Keywords: Theory of dynamical systems, Convex programming, Feedback control systems / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Orientadores: Rodney Carlos Bassanezi, Laecio Carvalho de Barros / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-04T03:22:11Z (GMT). No. of bitstreams: 1 Magnago_KarineFaverzani_D.pdf: 4968735 bytes, checksum: d2d7f169f303816c10985c62cb0bb240 (MD5) Previous issue date: 2005 / Resumo: Neste trabalho, nós estudamos o modelo logístico discreto com variável de estado incerta, modelada por meio de subconjuntos fuzzy; determinamos pontos fixos exclusivos da equação fuzzy correspondente, bem como uma família de órbitas periódicas assintoticamente estáveis. Realizamos simulações iterativas que podem também considerar a taxa de crescimento intrínseco incerta. Na seqüência, estudamos modelos de metapopulação de moscas varejeiras, aplicados às espécies Lucilia eximia e Chrysomya albiceps. Utilizamos sistemas baseados em regras fuzzy, com subjetividade de ambiente na estimativa da sobrevivência e migração. Consideramos migração dirigida e habitat fragmentado em sítios com distribuição espacial cíclica ou alinhada. Realizamos a análise dos equilíbrios no caso particular: dois sítios interligados, e simulações nos demais casos. Comparamos o modelo logístico discreto e o modelo local utilizado nos modelos de metapopulação propostos / Abstract: ln this work, we study discrete logistic model with uncertain state variable, modeled by fuzzy subsets; we determine fixed points of corresponding fuzzy equation, as well as a family of stable periodic orbits. We present simulations that can also consider uncertain intrinsic growth rate. We study metapoplllation models of blowfiies applied to the species Lucilia eximia and Chrysomya albiceps. We use fuzzy rules based systems with subjective environment to estimate survival and migration rates. We consider directional migration and habitat broken into fragments at patches with cyclic or aligned space distribution. We analyze the equilibria in the particular case: two interlinked patches, and we simulate in other cases. We compare discrete logistic model and the local model used in the proposed metapopulation models / Doutorado / Matematica Aplicada / Doutor em Matemática Aplicada

Orientadores: Romis Ribeiro de Faissol Attux, Diogo Coutinho Soariano, Filipe Ieda Fazanaro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-27T04:17:12Z (GMT). No. of bitstreams: 1 Santos_OdairVieirados_D.pdf: 3365036 bytes, checksum: 967476ee0acb26bf5197de95e344c6c9 (MD5) Previous issue date: 2015 / Resumo: O problema de análise do sincronismo entre sistemas dinâmicos se reveste de enorme importância prática, uma vez que ocorre em uma miríade de contextos naturais e artificiais. Para avaliar a ocorrência desse fenômeno, é usual lançar mão dos expoentes de Lyapunov condicionados, que refletem, em sua definição, o acoplamento entre sistemas. Nesta tese, é proposto um novo método para cálculo desses expoentes, que pode ser extremamente útil quando há descontinuidades ou quando o cálculo da matriz jacobiana é proibitivo. Esse método tem por base o método das dinâmicas clonadas para estimação do espectro convencional de Lyapunov. A nova proposta é validada em diversos cenários, partindo de sistemas clássicos e chegando aos modelos neuronais de Hindmarsh-Rose e Hodgkin-Huxley. O estudo do sincronismo uni- e bidirecional desses modelos, aliás, constitui também uma contribuição original do trabalho / Abstract: The problem of analyzing synchronism between dynamical systems is of enormous practical significance, as this phenomenon arises in several natural and artificial domains. To characterize the occurrence of synchronism, it is usual to employ the conditioned Lyapunov exponents, which reflect, in their definition, the coupling between systems. In this thesis, a new method for calculating these exponents is proposed, which can be extremely useful in the presence of discontinuities or when to calculate the Jacobian matrix is prohibitive. This method is based on the cloned dynamics approach for estimating the conventional Lyapunov spectrum. The new proposal is validated in a number of scenarios, ranging from classical systems to the Hindmarsh-Rose and Hodgkin-Huxley neuron models. The study of the uniand bidirectional synchronism of these models are apropos also an original contribution of this work / Doutorado / Automação / Doutor em Engenharia Elétrica