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Poor diet quality is a source of morbidity and mortality within the United States. Previous researchers have examined psychosocial influences on diet; however, the relationship between life chaos, a psychosocial measure, and diet quality was not known. The purpose of this cross-sectional survey study was to use the Life Chaos Scale and the Healthy Eating Index-2010 to collect data on life chaos and diet quality, consistent with the biopsychosocial model of health, from a sample of 103 U.S. adults. Regression analysis was used to construct a predictive model. According to the study results, life chaos was not a significant predictor of diet quality (p = .699), although household income, when added to the model, was a predictor of diet quality (p = .011). Although there was no relationship between life chaos and diet quality, life chaos could be found universally throughout household income levels. Additionally, diet quality had a negative correlation with household income. Life chaos was not a significant predictor of diet quality, while confirming the role of income in diet quality. As inequalities of health and nutrition continue to be better understood through studies such as this, social change efforts can be targeted in an evidence-based way to bring the health benefits of a high quality diet to more Americans starting with greater outreach to low-income individuals.

Charged particle chaos and its collective effects in different magnetic geometries are investigated in a sequence of various numerical experiments. The fields generated by the particles as a result of interaction with the background electric and magnetic fields is not accounted for in the simulation. An X-line is first used to describe the geometry of the magnetotail prior to magnetic reconnection and a study of the behavior of charged particles is done from a microscopic viewpoint. Another important geometry in the magnetotail prior to substorm onset is Bifurcated Current Sheet. The same analysis is done for this configuration. The existence of at least one positive Lyapunov exponent shows that the motion of the particles is chaotic. By using statistical mechanics, the macroscopic properties of this chaotic motion are studied. Due to particles being charged, an electric field (perpendicular to the magnetic field in weak magnetic field region) accelerates the particles on average. Finite average velocity in the direction of electric field gives rise to an effective resistivity even in a collisionless regime such as solar corona and the magnetotail. Starting from initial velocities that are chosen randomly from a uniform distribution, the evolution of these distributions tends to a Maxwellian by the end of the simulation that is somewhat analogous to collisions in a Lorentz gas model. The effective resistivity due to such collisions is estimated. Ohmic heating is found to occur as a result of such an effective resistivity. Such collisions due to collective particle effects are essentially a different mechanism from classical collision notion. These experiments are done for two types of ions found in the plasma sheet prior to substorm onset, viz., protons and oxygen ions. Observational evidence of oxygen ions in the central plasma sheet, which flow out along open field lines from the ionosphere, were also simulated in the same manner. Oxygen ions have been found to influence the bifurcation of the current sheet and are also important in reconnection and other nonohmic instabilities, such as Kelvin Helmholtz instability, due to their mass. It is found that acceleration in X-line scales with the mass of ion species and the resistivity remains constant for different electric field strengths. In a Bifurcated Current Sheet, the acceleration scales with the square of mass of ion species and the resistivity scales with the electric field. Also, the overall resistivity values found in a Bifurcated Current Sheet are an order of magnitude lower than that found in an X-line.

Neste trabalho, apresentamos resultados para um sistema dinâmico denominado como bilhar, que descreve a dinâmica de uma partícula de massa m, livre da influência de qualquer potencial externo, no interior de uma região delimitada por uma fronteira que pode ser estática ou móvel. A partícula é lançada de uma determinada posição no interior do bilhar, de modo a sofrer colisões elásticas ou inelásticas com a fronteira do modelo. Após a ocorrência de uma colisão, a partícula sofre uma reflexão especular com a fronteira, de modo que seu ângulo de incidência é igual ao ângulo de reflexão. Para o caso em que as colisões são elásticas e a fronteira estática, o módulo da velocidade da partícula permanece constante ao longo de todas as colisões, entretanto, se uma perturbação temporal for introduzida na fronteira do sistema, é permitida a variação no módulo da velocidade da partícula durante o impacto. Nesta tese, vamos estudar a dinâmica de um ensemble de partículas não-interagentes em um bilhar ovóide sob duas configurações diferentes. Inicialmente, a fronteira será assumida como estática e a partir de um mapeamento bidimensional que descreve a dinâmica do sistema, demonstramos que para esse tipo de bilhar o espaço de fases é do tipo misto, onde pode ser observado a coexistência de um mar de caos, ilhas de estabilidade e um conjunto de curvas invariantes do tipo spanning. Ainda para esse caso, introduzimos orifícios ao longo da fronteira do bilhar para estudar o comportamento do escape das partículas, via análise da probabilidade de sobrevivência P(n) que um conjunto de partículas no interior do sistema exibe, conforme o número de colisões n é aumentado. Através de simulações numéricas, verificamos que P(n) decai em média de forma exponencial com um expoente de decaimento dado aproximadamente pela razão entre a extensão do orifício h e o comprimento total da fronteira do bilhar. Ao longo deste estudo, observamos que devido a natureza mista do espaço de fases, existem regiões preferenciais para a visitação de partículas, o que pode fornecer pistas para a verificação da maximização ou minimização do escape no sistema. Posterior a isso, introduzimos uma perturbação temporal na fronteira do bilhar ovóide, e descrevemos todas as equações necessárias para a obtenção do mapeamento quadrimensional não-linear, que reproduzirá o movimento de uma partícula no interior do modelo com fronteiras oscilantes. O objetivo dessa análise, é a verificação da difusão ilimitada de energia por parte das partículas, conhecido como Aceleração de Fermi. Além de discutir todo o mecanismo envolvido nesse fenômeno, também analisamos formas possíveis para provocar a supressão desse crescimento ilimitado de energia exibido pelas partículas. Por último, propomos uma conexão entre os resultados referentes ao bilhar ovóide dependente do tempo com conceitos ligados à Termodinâmica. / In this work, we present some results for a dynamical system denoted as a billiard that describes the dynamics of a free particle of mass m inside of a region delimited by a boundary that might be static or time-dependent. The particle is launched from a region inside of the billiard and can experiences either elastic or inelastic collisions with the boundary. After a collision, the particle exhibits a specular reflection with the border, in such way that the incidence angle is equal to the reflected angle. When elastic collisions are taken into account the speed of the particle remains constant along all collisions. When a time-dependence is introduced on the boundary, then the particle may gain or lose energy upon collision. In this thesis, we will study the dynamics of an ensemble of non-interacting particles inside an oval billiard, under two different configurations. Initially, the boundary is considered as static and via a two-dimensional and nonlinear mapping, the dynamics of each particle is investigated. We show that for the static case the phase space is of mixing type with the coexistence of a chaotic sea, stability islands and a set of invariant spanning curves over the phase space. We then introduce holes along the boundary of the billiard allowing the particles to escape through them. We analyze the survivor probability P(n) that an ensemble of particles exhibits inside of the billiard as a function of n. Our results show that P(n) decays in average exponentially with a decay exponent given approximately by the size of the hole h over the total length of the boundary. Along this study, we observed that, due to the mixing structure of the phase space, there are preferential regions for the visitation of particles, which might be useful for the verification of the maximization or minimizations of the escape in the system. After that, we introduced a time-dependence on the boundary of the oval billiard and describe all the equations to obtained the nonlinear four-dimensional mapping used to reproduce the movement of particle inside of the billiard. The main goal of this analysis is the verification of the unlimited diffusion of energy from the particles, known as Fermi Acceleration. We discuss all the mechanism involved in such a phenomenon and discuss possibilities to promote the suppression of the unlimited energy growth in the billiard. Finally, we discuss a possible connection of the time-dependent oval billiard with concepts linked with Thermodynamics.

Sustainable development is now being recognised as a vital component of our society in the environmental, ethical, social, technological, economic, and institutional aspects, or dimensions, so, this thesis develops a framework to quantitatively measure sustainability. This thesis is distinctive in that it focuses on quantitative methods encapsulated in a formal assessment procedure and includes sustainability concepts that have rarely been put into practical use in sustainability reports. The framework is designed along the strategy that the methodology needs to be scale invariant and recursive, meaning the procedure is the same irrespective of the scale the user is interested in, and that different people can focus at different levels of sustainability by following a similar procedure. While the quantification process is aimed to be as unbiased as possible, a configuration of the tools from Total Quality Management (TQM) is adapted to identify sustainability indicators which are then mapped onto a scalar with mathematical functions. The sustainability indices are presented according to the amount of details needed by different users ─ some may need just one overall figure while others may need sustainability indices broken down by the six sustainability dimensions and presented on a spider diagram, while others may need all the details for analysis. This methodology also caters for sustainability analysis by different stakeholders. To fully demonstrate the potential of the methodology, the author has chosen to test it on a large-size industry sector so that it can have the capacity to be scaled up to a country or down to a small business, and on an industry sector that is important on its own right. Furthermore, this sector needs to be illustrative and has nontrivial complex problems. Under these criteria, the electricity sector of New Zealand was selected. The robustness of the methodology was investigated with inputs from three evaluators with different views: a standard view from the author that was made after much research in the sector and in the concepts of sustainability, a view with an environmental bias and one that focuses on commercial interests.

Visa是全球第一大的國際支付卡組織，然其自1970年成立至今，不過短短30年，這之間組織成長的速度令人驚嘆，但由從前組織成長理論似乎無法解釋其中所隱含的經濟意義，因此本研究嘗試以新經濟現象中的網路外部性理論來觀察解釋Visa組織成長的過程-隨著使用者的增加，整個系統的價值也隨之增加，且在不斷的循環自我增強下，整個系統呈現非線性的快速成長。 此外，Visa組織的創辦者Dee Hock(1998)在「亂序」一書中提及Visa是個亂序（處於混亂和秩序之間）的組織，因此本研究亦由混沌理論的觀點觀察Visa組織的運作方式，瞭解其是如何進行自我組織、自我成長、自我演化，又這樣一個龐大的價值交換體系，在快速成長擴充的過程中又是如何管理運作的。 最後，本研究就網路外部性和混沌理論觀點下所觀察到的現象進行進一步之比較探討，找出其中相關之處，觀察兩者間是否有互相強化之關連，發覺Visa此一混沌邊緣組織的運作方式強化了其網路外部性的效果，也更加造就了Visa的成功。

La première partie de la thèse concerne l'étude d'une classe particulière de systèmes dynamiques déterministes présentant deux problèmes: la présence de points fixes neutres et des points de discontinuité auxquels la dérivée n'est pas bornée. La seconde partie traite des systèmes dynamiques aléatoires: du problème de la récurrence dans ce type de système puis de leur application à la modélisation de petites perturbations stochastiques. On traite en particulier du problème de la stabilité stochastique.

Dans cette thèse, on étudie deux paradigmes du chaos quantique: celui des symplectomorphismes linéaires du tore et celui du flot géodésique sur une variété riemannienne compacte. Dans les deux cas, on étudie le problème d'ergodicité quantique associé. Les résultats obtenus sont de deux sortes. D'une part, on obtient des bornes inférieures sur l'entropie des mesures semi-classiques en dimension 2. D'autre part, on obtient des résultats de type grandes déviations semi-classiques en toute dimension.

Le terme « chaos ondulatoire » désigne l'étude du comportement des ondes dans des sys- tèmes fermés dont la limite géométrique des rayons exhibe une dynamique chaotique. Cette dernière est révélée notamment par l'extrême instabilité de trajectoires que sont les orbites pé- riodiques. Comment les ondes se comportent-elles dans un système dont la limite géométrique suit une dynamique chaotique ? Dans certaines conditions particulières, elles peuvent figer le développement de la dynamique chaotique et concentrer leur énergie le long d'orbites pério- diques instables, donnant lieu à l'existence de modes singuliers, les « Scars », présentant des surintensités localisées le long de ces trajectoires. Le travail présenté dans cette thèse résulte d'une volonté de contrôler activement les modes d'un système chaotique, dans le but de faire émerger expérimentalement les modes scar. Nous introduisons un milieu à gain dans une fibre optique multimode à section transverse chaotique, système privilégié pour l'étude du chaos ondulatoire. La localisation spatiale de ce gain nous permet de contrôler l'émergence d'une fa- mille de « scars » en les amplifiant sélectivement. Nous présentons des simulations numériques validant le processus physique d'amplification, suivies d'une étude expérimentale démontrant l'amplification sélective de modes « scar » dans une fibre optique multimode.

Le chaos quantique désigne l'étude de systèmes dont le prolongement classique est chaotique. Le modèle du pendule pulsé, qui en est un exemple paradigmatique, est réalisé expérimentalement en plaçant un échantillon d'atomes refroidis (MOT) dans une onde stationnaire pulsée formée par un faisceau laser retro-reflechi. L'étude de la dynamique s'appuie sur la mesure de la distribution d'impulsions des atomes. <br />Après avoir retrouvé expérimentalement le phénomène quantique de localisation dynamique, lié au caractère périodique de la séquence de pulses, la destruction de ce phénomène (délocalisation dynamique) par l'utilisation de séquences superposant deux séries de pulses de période (séquence bicolore) est étudiée puis expliquée par un modèle théorique. Cette analyse suggère que la délocalisation est, dans ce contexte, réversible. Il est ainsi montré expérimentalement qu'une séquence bicolore inversée conduit une délocalisation suivie d'une relocalisation.