Neste trabalho estuda-se a interação, através de choques, entre um oscilador harmônico e um carro de trilho de ar inclinado, análogo ao sistema descrito na literatura como \"bouncing-ball\". A análise teórica e a simulação prevêem estabilidade e bifurcação nas fases do oscilador em que ocorrem os choques, confirmados pela experiência. As simulações indicam a ocorrência de caos, fato que foi confirmado experimentalmente. O sistema experimental de aquisição de dados produzido permite a utilização no ensino de graduação. Os dados experimentais gerados pelo sistema são coletados por uma interface de aquisição, que trabalha acoplada a um microcomputador Apple II, e transferidos para um microcomputador tipo IBM-PC, possibilitando uma análise rápida dos resultados obtidos. Para a visualização das regiões de estabilidade, de bifurcação e do atrator estranho, que surge na região de caos, foram desenvolvidos programas gráficos e de cálculo, que permitem, também, realizar uma avaliação da dimensão do atrator. Os programas de simulação permitem ao aluno realizar cálculos e gerar gráficos, variando os parâmetros de controle do sistema. No experimento foi utilizado coeficiente de restituição E de 0,22 e a dimensão fractal encontrada para o atrator foi 1,2. / In the present dissertation the interaction between an harmonic oscillator and an air track\'s glider is studied, analogous to the system described in literature as the bouncing-ball. Theoretical analysis and simulation predict stability and bifurcation in the phases of the oscillator in which occur collisions. The simulations indicate the occurrence of chaos, a fact confirmed experimentally. The built up experimental data acquisition system can be used in undergraduate teaching. Experimental data generated by the system are collected by na acquisition interface, which works linked to an Apple II microcomputer, and are transferred to an IBM-PC type microcomputer, allowing quick analysis of the obtained results. To visualize the regions of stability, of bifurcation and of the strange attractor, graphic and calculation programs were developed, which also permit an evaluation of the attractor\'s dimension. The simulation programs allow the student to do calculations and generate graphs, while varying the system\'s control parameters. In the experiment a restitution coefficient E of 0.22 was used and the found fractal dimension for the attractor was 1.2.

Il s’agit d’une thèse menée en sciences de l’art, plus particulièrement en poïétique et esthétique, d’un praticien sculpteur qui réfléchi sur la notion du chaos et la surface dans la sculpture contemporaine. J’ai commencé par mon approche poïétique et celles des autres, comme ceux qui sont à l’origine de l’Arte Povera et du Land Art. Une partie graphique, consistera à traiter ce rapport à travers mon journal d’artiste, un journal du quotidien et du banal à travers le dessin, qui n’est pas seulement un moyen de représentation mais il est un outil de connaissance et de production le réel, il est aussi une façon d’explorer la nature et une manière de comprendre le chaos et de produire la surface. Pour la partie plastique, je sollicite l’utilisation de matériaux trouvés dans ma région natale. Ces matériaux sont touffus, pleins de branches entremêlées, aucune organisation n’est visible. Cette thèse ouvre la voie sur une réflexion qui met l’accent sur les notions du chaos et de la surface. Dans la première partie se pose la question de la création - recherche. Ensuite on a posé la question du chaos et de la surface d’une façon générale en appuyant la réflexion sur des références sûres comme celles de Reynal Sorel (Mythologie et philosophie grecques) Maurice Merleau-Ponty (phénoménologie), Gilles Deleuze et Clément Rosset (philosophie), Jacqueline Lichtenstein (Histoire de l’art et esthétique). Toujours chaos et surface vont ensemble, ils sont complémentaires. On a traité ce duel dans des cas particuliers, comme Auguste Rodin, Henry Moore, de Jean (Hans) Arp et d’artistes d’Arte Povera et du Land Art. / This is a thesis conducted in the science of art, especially in poetics and aesthetic s by a practitioner sculptor who reflected on the notion of chaos and the surface in contemporary sculpture. I started with my approach about poetics and that of other artists, such as those at the origin of the Arte Povera and Land Art. Some graphics will treat this report through my journal as an artist, a daily and banal journal, and through drawing, which is not only a means of representation but it is a tool of knowledge and the production of reality, it is also a way to explore nature and a way of understanding chaos and to produce the surface .The plastic part requests the use of materials found in my home area. These materials are dense, full of tangled branches, where there is no visible order. This thesis opens a discussion that focuses on the concepts of chaos and the surface. In the first part is the issue of creation - research. Then we dealt with the issue of chaos and the surface of a general reflection on supporting references such as Reynal Sorel (Greek mythology and philosophy) Maurice Merleau-Ponty (Phenomenology), Gilles Deleuze and Clément Rosset (philosophy), Jacqueline Lichtenstein (art history and aesthetics). Surface and chaos are always together, they are complementary .We treat this duel in special cases, such as Auguste Rodin, Henry Moore, Jean (Hans) Arp and artists of Arte Povera and Land Art.

No description available.

Shock waves in reactive media possess very rich dynamics: from formation of cells in multiple dimensions to oscillating shock fronts in one-dimension. Because of the extreme complexity of the equations of combustion theory, most of the current understanding of unstable detonation waves relies on extensive numerical simulations of the reactive compressible Euler/Navier-Stokes equations. Attempts at a simplified theory have been made in the past, most of which are very successful in describing steady detonation waves. In this work we focus on obtaining simplified theories capable of capturing not only the steady, but also the unsteady behavior of detonation waves. The first part of this thesis is focused on qualitative theories of detonation, where ad hoc models are proposed and analyzed. We show that equations as simple as a forced Burgers equation can capture most of the complex phenomena observed in detonations. In the second part of this thesis we focus on rational theories, and derive a weakly nonlinear model of multi-dimensional detonations. We also show, by analysis and numerical simulations, that the asymptotic equations provide good quantitative predictions.

Quantum chaos has emerged in the half of the last century with the notorious problem of scattering of heavy nuclei. Since then, theoreticians have developed powerful techniques to approach disordered quantum systems. In the late 70's, Casati and Chirikov initiated a new field of research by studying the quantum counterpart of classical problems that are known to exhibit chaos. Among the several quantum-classical chaotic systems studied, the kicked rotor stimulated a lot of enthusiasm in the scientific community due to its equivalence to the Anderson tight binding model. This equivalence allows one to map the random Anderson model into a set of fully deterministic equations, making the theoretical analysis of Anderson localization considerably simpler. In the one-dimensional linear regime, it is known that Anderson localization always prevents the diffusion of the momentum. On the other hand, for higher dimensions it was demonstrated that for certain conditions of the disorder parameter, Anderson localized modes can be inhibited, allowing then a phase transition from localized (insulating) to delocalized (metallic) states. In this thesis we will numerically and theoretically investigate the properties of a multidimensional quantum kicked rotor in a nonlinear medium. The presence of nonlinearity is particularly interesting as it raises the possibility of having soliton waves as eigenfunctions of the systems. We keep the generality of our approach by using an adjustable diffusive nonlinearity, which can describe several physical phenomena. By means of Variational Calculus we develop a chaotic map which fully describes the soliton dynamics. The analysis of such a map shows a rich physical scenario that evidences the wave-particle behavior of a soliton. Through the nonlinearity, we trace a correspondence between quantum and classical mechanics, which has no equivalent in linearized systems. Matter waves experiments provide an ideal environment for studying Anderson localization, as the interactions in these systems can be easily controlled by Feshbach resonance techniques. In the end of this thesis, we propose an experimental realization of the kicked rotor in a dipolar Bose Einstein Condensate.

Dynamical systems possess an interesting and complex behaviour that have attracted a number of researchers across different fields, such as Biology, Economics and most importantly in Engineering. The complex and unpredictability of nonlinear customary behaviour or the chaotic behaviour, makes it strange to analyse them. This thesis presents the analysis of the system of nonlinear differential equations of the so--called Lu--Chen--Cheng system. The system has similar dynamical behaviour with the famous Lorenz system. The nature of equilibrium points and stability of the system is presented in the thesis. Examples of chaotic dynamical systems are presented in the theory. The thesis shows the dynamical structure of the Lu--Chen--Cheng system depending on the particular values of the system parameters and routes to chaos. This is done by both the qualitative and numerical techniques. The bifurcation diagrams of the Lu--Chen--Cheng system that indicate limit cycles and chaos as one parameter is varied are shown with the help of the largest Lyapunov exponent, which also confirms chaos in the system. It is found out that most of the system's equilibria are unstable especially for positive values of the parameters $a, b$. It is observed that the system is highly sensitive to initial conditions. This study is very important because, it supports the previous findings on chaotic behaviours of different dynamical systems.

Chaos is a complex dynamics with exponential sensitivity to the initial conditions. Since the study of three-body problem by Henri Poincare, chaos has been extensively studied in many systems, ranging from electronics to fluids, brains and more recently photonics. Chaos is a ubiquitous phenomenon in Nature, from the gigantic oceanic waves to the disordered scales of white beetles at nanoscale. The presence of chaos is often unwanted in applications, as it introduces unpredictability,which makes it difficult to predict or explain experimental results. Inspired by how chaos permeates the natural world, this thesis investigates on how the interaction between light and chaotic structure can enhance the performance of photonics devices. With a proper design of the lighter-mater interaction in chaotic resonators, I illustrate how chaos can be used to enhance the ability of an optical cavity to store electromagnetic energy, realize a blackbody system composed of gold nanoparticles, localize light beyond the diffraction limit and control the phase transition of super-radiance.

Work with gallery space, painting, objects, and theirs context.

Internalizing behaviors, or behaviors related to behavioral inhibition and the tendency to withdraw from novelty or uncertainty, are stable over time. There is substantial evidence indicating the association between greater resting right lateralized frontal EEG alpha asymmetry and negative affect as well as internalizing behaviors (Coan & Allen, 2003; Henderson, Fox, & Rubin, 2001; Fox, 1991). Further, right frontal asymmetry has been shown to be a stable marker of the presence of psychosocial risk (e.g. child maltreatment; see Peltola, Bakermans-Kranenburg, Alink, Huffmeijer, Biro, & van IJzendoorn, 2014 for meta-analyses). However, little is known about the influences of the home and family environment on the link between EEG asymmetry and behavior. The current study examines the associations between resting frontal EEG asymmetry, temperament, and internalizing behaviors in the context of household chaos, as well as additional models. Participants included 247 6-year-old children recruited as part of a larger study on emotion regulation. Results suggest that while household chaos is marginally associated with concurrent internalizing behaviors, the association does not differ depending on patterns of hemispheric asymmetry. Methodological considerations and future directions are discussed. By understanding the physiological mechanisms underlying risk for internalizing problems as well as potential moderators of this link we can better inform the development and timing of effective prevention strategies.

In the design of material handling systems with complex and unpredictable dynamics, conventional search and optimization approaches that are based only on performance measures offer little guarantee of robustness. Using evidence from research into complex systems, the use of behavior-based optimization is proposed, which takes advantage of observed relationships between complexity and optimality with respect to both performance and robustness. Based on theoretical complexity measures, particularly algorithmic complexity, several simple complexity measures are created. The relationships between these measures and both performance and robustness are examined, using a model of a directly connected material handling system as a backdrop. The fundamental causes of the relationships and their applicability in the proposed behavior-based optimization approach are discussed. / Ph. D.