Orientadores: José Raimundo de Oliveira, Ignacio Bravo Muñoz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T12:37:43Z (GMT). No. of bitstreams: 1 Fazanaro_FilipeIeda_D.pdf: 53323687 bytes, checksum: 76694b226ed99a337ecee1769ed9c4e0 (MD5) Previous issue date: 2012 / Résumén: Esta tesis tiene como objetivo la caracterización de sistemas dinámicos no lineales y abruptos. Se propone una nueva metodología para la estimación del espectro de Lyapunov capaz de superar las dificultades relacionadas en los sistemas basados en funciones lineales por partes sobre la aplicación de los métodos clásicos de cálculo (cuando se utiliza linealización local o análisis de series de las series temporales experimentales). Este enfoque, denominado como Dinámica de los Clones, realiza la estimación del espectro de Lyapunov y también mejora el estudio de las características topológicas relacionadas con los procesos de mezcla que dan lugar al comportamiento caótico. Este estudio se lleva a cabo utilizando las Estructuras Coherentes de Lagrange que pueden obtenerse a través de la construcción de un campo de Exponentes de Lyapunov de Tiempo Finito donde se puede identificar a las crestas (o las separatrices) que dan la posibilidad de identificar las distintas regiones de convergencia y divergencia del espacio de estados. Debido al hecho que esta tesis se desarrolla fundamentalmente bajo un ordenador, los aspectos prácticos involucrados en los experimentos numéricos necesarios, emplean algunos conceptos y herramientas de computación en paralelo. Esto último permitió la optimización de los algoritmos implementados. Por lo tanto, los experimentos se realizaron para verificar la eficacia del enfoque de las Dinámicas Clonadas para la caracterización del circuito de Chua, y también para obtener las Estructuras Coherentes de Lagrange que tienen relación con los modelos dinámicos capaces de generar atractores caóticos multiscroll / Resumo: Essa tese objetiva caracterizar sistemas dinâmicos não lineares não suaves. Para tal, é proposta uma nova abordagem de estimação do espectro de Lyapunov capaz de contornar as dificuldades intrínsecas aos sistemas estruturados por funções lineares por partes quando da aplicação de metodologias clássicas (baseadas em linearizações locais ou em análises de séries temporais). Essa abordagem possibilita a estimação do espectro de Lyapunov e, além disso, auxilia no estudo das características topológicas relacionadas aos processos de mistura que dão origem ao comportamento caótico. Essa linha de estudo é realizada através das Estruturas Lagrangianas Coerentes, as quais são obtidas pela construção de um campo de Expoentes de Lyapunov de Tempo Finito, onde é possível identificar cristas (ou separatrizes) que dividem regiões de convergência e de divergência no espaço de estados. Por se tratar de um trabalho basicamente computacional, essa tese contempla os aspectos práticos envolvidos para a realização dos experimentos numéricos através da utilização de alguns conceitos e ferramentas de computação paralela, o que possibilitou a otimização dos algoritmos implementados. Nesse sentido, os experimentos foram realizados de modo a verificar a eficácia da metodologia proposta para a caracterização do circuito de Chua e, ainda, foram obtidas as Estruturas Lagrangianas Coerentes para os modelos dinâmicos capazes de gerar atratores caóticos multiscroll / Abstract: This thesis aims to characterize non-smooth nonlinear dynamical systems. To accomplish this purpose, we propose a new approach for estimating the Lyapunov spectrum which is capable to overcome the intrinsic difficulties of classical methods (based on local linearization or time series analysis) when dealing with systems based on piecewise linear functions. This approach, called Cloned Dynamics, allows the estimation of the Lyapunov spectrum and also improves the study of the topological features related to the mixing processes that give rise to the chaotic behavior. This study is performed using the Lagrangian Coherent Structures which are obtained by the construction of a Finite Time Lyapunov Exponents field where it is possible to identify the ridges (or the separatrices) which divide the convergence and divergence regions of the state space. Due to the fact that this thesis is basically developed under a computer environment, the practical features involved in the numerical experiments employing some parallel computing concepts and tools are discussed, which allowed the optimization of the algorithms implemented. In this sense, experiments were performed to verify the effectiveness of the Cloned Dynamics approach for the characterization of the Chua's circuit, and also to obtain the Lagrangian Coherent Structures related to the dynamical models capable of generating multiscroll chaotic attractors / Doutorado / Automação / Doutor em Engenharia Elétrica

This thesis constitutes a narrative that explores an alternative meaning construction for the experience of loss. During the telling of this story, I consider the appropriateness of adopting the 'new paradigm' approach for this particular thesis, and the constructivist and social constructionist epistemological assumptions underlying such an approach. I delve into the use of 'self as researcher under this epistemological umbrella. This is followed by an exploration of 'chaos theory' and its application to social systems. And finally, I consider the usefulness of this theory in constructing meanings for loss experiences on various systemic levels within my own family system. / Psychology / M.A.(Clinical Psychology)

Thesis (MA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The advent of the computer age has seen many fundamental changes in the economics. The ease with which organisations can store and transmit information in unprecedented quantities and speeds has changed the face of the economy as well as the way in which organisations conduct their day to day operations. Information has become the primary resource for organisational competitiveness and this has seen an increasing drive for efficient information generation and management in an economy that is interconnected on a global scale. The demand for better information management practices is driven by the realisation that the global economy is susceptible to sudden and unpredictable changes that can potentially have global consequences. The more information organisations have at their disposal, the better their chances are of remaining competitive and relevant in the global economy. The informational economy confronts organisations with two very significant problems, the first is information overload due to the sheer volume of information that is available to them. The second problem is that despite the volume of available information organisations still are not privy to all the information that is required to lessen the impact of uncertainty that is so characteristic of the global economy. Organisations therefore always run the' risk of becoming irrelevant if they do not change constantly. This drive for continuous change and the dependence on information has led some organisational theorists and economists to compare the global economy and organisations to nonlinear systems found in nature. Examples of nonlinear systems are living organisms, ecologies and solar systems. All of these systems are characterised by high levels of interconnectedness and interdependence among individual units within a shared environment, which they co-create. Nonlinear systems are of particular interest to organisational theorists because these systems process information about the environment to adapt in an unpredictable way to unpredictable changes. Such systems are incredibly resilient because they are able to learn and adapt to different conditions. Another notable aspect of nonlinear systems is the clear structured and complex organisation that they exhibit in the absence of centralised control mechanisms. Every unit has the liberty to experiment with new designs and from the success of individual units an organised and stable system emerges with a strong link between the success of individuals and the whole system. The order that exists within nonlinear systems is known as self-organisation because it is not superimposed but emerges instead in a spontaneous manner. Nonlinear systems are therefore more than just the sum of their parts. The notion of nonlinear systems and self-organisation has seen authors such as Stacey, Wheatley and Senge develop new ideas about organisational development, leadership and organisational strategic thinking. Their ideas are based on what is popularly known as 'The New Science'. These ideas attempt to encourage organisations realise that the global economy functions as a nonlinear system and that organisations stand a better chance of success if they learn to understand the principles of nonlinear systems and to utilise the inherent creative and organising characteristics of such systems. / AFRIKAANSE OPSOMMING: Die aanvang van die rekenaar era het verskeie fundamentele veranderinge in ekonomie mee gebring. Die gemak en snelheid waarmee organisasies informasie kan stoor en versprei is ongekend en het terselfde tyd die voorkoms van die ekonomie verander asook die wyse waarop organisasies op 'n daaglikse basis funksioneer. Informasie het die belangrikste hulpbron geword vir organisasies in terme van kompetering en dit het 'n groter dryfkrag vir doeltreffende informasie ontginning en bestuur mee gebring in 'n ekonomie wat op 'n wereldwye skaal in mekaar gevleg is. Die aanvraag vir beter informasie bestuur praktyke word gedryf deur die wete dat die wereld ekonomie vatbaar is vir skielike en onvoorspelbare veranderinge wat potensieel 'n wereldwye impak kan he. Hoe meer informasie organisasies tot hul beskikking het hoe beter is hul kans om relevant en kompeterend te bly in die wereld ekonomie. Die informasie ekonomie konfronteer organisasies met twee fundamentele probleme. Die eerste gevaar is dat organisasies oorlaai kan word met informasie as gevolg van die absolute volume van beskikbare informasie. Die tweede probleem spruit voort uit die feit dat ten spyte van die beskikbare informasie, lei organisasies steeds aan 'n gebrek aan algehele informasie, organisasies kan dus nooit toegang he tot al die informasie wat benodig word om die impak te verminder van die onsekerheid wat so kenmerkend is van die wereld ekonomie. Organisasies loop dus altyd die gevaar om irrelevant te raak as hulle nie konstant aanpas by nuwe omstandighede nie. Hierdie soeke na konstante verandering en die afhanklikheid op informasie het verskeie organisasie teoretici en ekonome daartoe gelei om 'n vergelyking te tref tussen die wereld ekonomie en organisasies aan die een kant en nie-Iiniere sisteme wat in die natuur voorkom. Voorbeelde van sulke sisteme sluit lewende organismes, ekostelsels en sterre stelsels in. Die komponente van al hierdie sisteme is op 'n komplekse wyse inmekaar geweef en interafhanklik op mekaar binne die raamwerk van gemeenskaplike omgewing waarvoor hierdie komponente mede verantwoordelik is. Nie-liniere sisteme is van besondere belang vir organisasie teoretici omdat die betrokke sisteme informasie verwerk aangaande hul omgewing om op 'n onvoorspelbare wyse aan te pas by onvoorspelbare veranderinge in die omgewing. Sulke sisteme is uitsonderlik standvastig deurdat hulle kan leer en aanpas by verskillende omstandighede. Nog 'n merkbare aspek van sulke sisteme is die duidelik gestruktureerde en komplekse organisasie wat bestaan ten spyte van 'n algehele gebrek aan gesentraliseerde beheer meganismes. Elke komponent is vry om met 'n nuwe ontwerp te eksperimenteer en vanuit die sukses van die komponente spruit die sukses van die sisteem. Die organisasie wat sigbaar is in nie-liniere sisteme staan bekend as self-organisasie omdat dit nie voortspruit uit 'n sentrale beheer meganisme nie maar instede spontaan onstaan as 'n gevolg van die aksies van komponente. Nie-Iiniere sisteme het die potensiaal om meer te kan wees as die somtotaal van hul komponente. Die beginsel van nie-liniere sisteme en selforganisasie het skrywers soos Stacey, Wheatley en Senge daartoe gelei om nuwe idees te ontwikkel rakende organisasie ontwikkeling, leierskap en strategiese beplanning in organisasies. Hierdie idees is gegrond in wat algemeen bekend staan as 'The New Science'. Die idees van hierdie skrywers is gemik daarop om organisasies aan te moedig om raak te sien dat die wereld ekonomie soos 'n nie-liniere sisteem funksioneer en dat organisasies as sulks 'n beter kans staan om sukses te behaal as hulle sou leer om die beginsels van nie-liniere sisteme te begryp en die inherente kreatiewe en organiserings eienskappe van sulke sisteme uit te buit.

This thesis constitutes a narrative that explores an alternative meaning construction for the experience of loss. During the telling of this story, I consider the appropriateness of adopting the 'new paradigm' approach for this particular thesis, and the constructivist and social constructionist epistemological assumptions underlying such an approach. I delve into the use of 'self as researcher under this epistemological umbrella. This is followed by an exploration of 'chaos theory' and its application to social systems. And finally, I consider the usefulness of this theory in constructing meanings for loss experiences on various systemic levels within my own family system. / Psychology / M.A.(Clinical Psychology)

Este trabalho apresenta uma metodologia, baseada no método de Galerkin, para quantificar a incerteza no problema de flexão estocástica da viga de Euler-Bernoulli repousando em fundação de Pasternak. A incerteza nos coeficientes de rigidez da viga e da fundação é representada por meio de processos estocásticos parametrizados. A limitação em probabilidade dos parâmetros randômicos e a escolha adequada do espaço de soluções aproximadas, necessárias à posterior demonstração de unicidade e existência do problema, são consideradas por meio de hipóteses teóricas. O espaço de soluções aproximadas de dimensão finita é construído pelo produto tensorial entre espaços (determinístico e randômico), obtendo-se um espaço denso no espaço das soluções teóricas. O esquema de Wiener-Askey dos polinômios do caos generalizados é utilizado na representação do processo estocástico de deslocamento da viga. O método dos elementos finitos estocásticos é apresentado e empregado na solução numérica de exemplos selecionados. Os resultados, em termos de momentos estatísticos, são comparados aos obtidos por meio de simulações de Monte Carlo. / This study presents a methodology, based on the Galerkin method, to quantify the uncertainty in the stochastic bending problem of an Euler-Bernoulli beam resting on a Pasternak foundation. The uncertainty in the stiffness coefficients of the beam and foundation is represented by parametrized stochastic processes. The probability limitation on the random parameters and the choice of an appropriated approximate solution space, necessary for the subsequent demonstration of uniqueness and existence of the problem, are considered by means of theoretical hypothesis. The finite dimensional space of approximate solutions is built by tensor product between spaces (deterministic and randomic), obtaining a dense space in the theoretical solution space. The Wiener-Askey scheme of generalizes chaos polynomials is used to represent the stochastic process of the beam deflection. The stochastic finite element method is presented and employed in the numerical solution of selected examples. The results, in terms of statistical moments, are compared to results obtained through Monte Carlo simulations.

Indiana University-Purdue University Indianapolis (IUPUI) / This paper is a study of the dynamics of a new family of maps from the complex plane to itself, which we call twisted tent maps. A twisted tent map is a complex generalization of a real tent map. The action of this map can be visualized as the complex scaling of the plane followed by folding the plane once. Most of the time, scaling by a complex number will \twist" the plane, hence the name. The "folding" both breaks analyticity (and even smoothness) and leads to interesting dynamics ranging from easily understood and highly geometric behavior to chaotic behavior and fractals.

A presente dissertação propõe a resolução do problema de flexão estocástica em uma viga Euler-Bernoulli, sobre uma fundação do tipo Pasternak, através de um método computacional baseado na simulação de Monte Carlo. A incerteza está presente nos coeficientes elásticos da viga e da fundação. Primeiramente, é estabelecida a formulação matemática do problema que é oriunda, de um modelo físico de deslocamento da viga, que leva em consideração a influência da fundação sobre a resposta do problema. Portanto foi realizado um estudo a cerca dos modelos mais usuais de fundação, que são: o modelo do tipo Winkler, e modelo de Pasternak. Logo a seguir foi provado que o problema variacional abstrato, derivado da formulação forte do problema, apresenta solução e esta é única. Para a obtenção da solução do problema, foi realizada uma fundamentação matemática, dos seguintes assuntos: representação da incerteza, método de Galerkin, série de Neumann, e por fim das cotas inferiores e superiores. Finalmente, o desempenho das cotas inferiores e superiores, em relação à simulação de Monte Carlo direto, foram avaliadas através de vários casos, nos quais a incerteza repousa sobre os diversos coeficientes que compõe a equação de flexão na forma de um problema variacional. A metodologia mostrou-se eficiente, tanto no aspecto da convergência da resposta quanto no que se refere ao custo computacional. / This work proposes the resolution of stochastic bending problem in a Euler- Bernoulli beam, on a foundation type Pasternak, through a computational method based on Monte Carlo simulation. Uncertainty is present in the elastic coefficients of the beam and foundation. First, it is established the mathematical formulation of the problem which is derived from a physical model displacement of the beam, that takes into account the influence of the foundation on the problem of response. This requires an approach that is made up on the most common models of foundation, which are: the model Winkler type and model of Pasternak.In sequence we study the existence and uniqueness of the variational problem. To obtain the solution of the problem, a mathematical reasoning is carried out, to the following matters: representation of uncertainty, Galerkin method, serial Neumann, and finally the lower and upper bounds. Finally, the performance of lower and upper bounds, derived from direct simulation of Monte Carlo were evaluated through various cases where the uncertainty lies in the different coefficients composing the equation bending as a variational problem. The method proved to be efficient, both in the response of the convergence point as regards the computational cost.

A presente dissertação propõe a resolução do problema de flexão estocástica em uma viga Euler-Bernoulli, sobre uma fundação do tipo Pasternak, através de um método computacional baseado na simulação de Monte Carlo. A incerteza está presente nos coeficientes elásticos da viga e da fundação. Primeiramente, é estabelecida a formulação matemática do problema que é oriunda, de um modelo físico de deslocamento da viga, que leva em consideração a influência da fundação sobre a resposta do problema. Portanto foi realizado um estudo a cerca dos modelos mais usuais de fundação, que são: o modelo do tipo Winkler, e modelo de Pasternak. Logo a seguir foi provado que o problema variacional abstrato, derivado da formulação forte do problema, apresenta solução e esta é única. Para a obtenção da solução do problema, foi realizada uma fundamentação matemática, dos seguintes assuntos: representação da incerteza, método de Galerkin, série de Neumann, e por fim das cotas inferiores e superiores. Finalmente, o desempenho das cotas inferiores e superiores, em relação à simulação de Monte Carlo direto, foram avaliadas através de vários casos, nos quais a incerteza repousa sobre os diversos coeficientes que compõe a equação de flexão na forma de um problema variacional. A metodologia mostrou-se eficiente, tanto no aspecto da convergência da resposta quanto no que se refere ao custo computacional. / This work proposes the resolution of stochastic bending problem in a Euler- Bernoulli beam, on a foundation type Pasternak, through a computational method based on Monte Carlo simulation. Uncertainty is present in the elastic coefficients of the beam and foundation. First, it is established the mathematical formulation of the problem which is derived from a physical model displacement of the beam, that takes into account the influence of the foundation on the problem of response. This requires an approach that is made up on the most common models of foundation, which are: the model Winkler type and model of Pasternak.In sequence we study the existence and uniqueness of the variational problem. To obtain the solution of the problem, a mathematical reasoning is carried out, to the following matters: representation of uncertainty, Galerkin method, serial Neumann, and finally the lower and upper bounds. Finally, the performance of lower and upper bounds, derived from direct simulation of Monte Carlo were evaluated through various cases where the uncertainty lies in the different coefficients composing the equation bending as a variational problem. The method proved to be efficient, both in the response of the convergence point as regards the computational cost.

The neural net computer simulations which will be presented here are based on the acceptance of a set of assumptions that for the last twenty years have been expressed in the fields of information processing, neurophysiology and cognitive sciences. First of all, neural networks and their dynamical behaviors in terms of attractors is the natural way adopted by the brain to encode information. Any information item to be stored in the neural net should be coded in some way or another in one of the dynamical attractors of the brain and retrieved by stimulating the net so as to trap its dynamics in the desired item's basin of attraction. The second view shared by neural net researchers is to base the learning of the synaptic matrix on a local Hebbian mechanism. The last assumption is the presence of chaos and the benefit gained by its presence. Chaos, although very simply produced, inherently possesses an infinite amount of cyclic regimes that can be exploited for coding information. Moreover, the network randomly wanders around these unstable regimes in a spontaneous way, thus rapidly proposing alternative responses to external stimuli and being able to easily switch from one of these potential attractors to another in response to any coming stimulus.<p><p>In this thesis, it is shown experimentally that the more information is to be stored in robust cyclic attractors, the more chaos appears as a regime in the back, erratically itinerating among brief appearances of these attractors. Chaos does not appear to be the cause but the consequence of the learning. However, it appears as an helpful consequence that widens the net's encoding capacity. To learn the information to be stored, an unsupervised Hebbian learning algorithm is introduced. By leaving the semantics of the attractors to be associated with the feeding data unprescribed, promising results have been obtained in term of storing capacity. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

Indiana University-Purdue University Indianapolis (IUPUI) / In his novels Slaughterhouse-five and The Sirens of Titan, Kurt Vonnegut explores issues of cultural identity in technologically-advanced societies post-World War II. With the rise of globalization and rapid technological advancements that occurred postwar, humans worldwide were mitigating the effects of information overload and instability in cultural identity. The influx of cultural influences that accompany a global society draws attention to the fluidity and inevitability of cultural change. A heightened awareness of cultural influences—past and present—creates anxiety for the generation living postwar and before the dawn of the Information Age. This generation suffers from “cultural schizophrenia”: a fracturing of the psyche characterized by anxiety over unstable cultural identities and agency. With the characters of Billy Pilgrim and Winston Niles Rumfoord, Vonnegut explores the different reactions to and consequences of cultural schizophrenia. His unique writing style is an effective hybrid of science fiction conventions and the complexities of human culture and society. Ultimately, Vonnegut explores the dangers of detachment and the complicated nature of agency with novels that are both innovative and accessible.