The understanding of the emergent behaviour of complex systems is probably one of the most intriguing challenges in modern theoretical physics. In the present Thesis we use novel data analysis techniques and numerical simulations in order to shed some light on the fundamental mechanisms involved in their dynamics. We divide the main core of the research into three parts, each of which address a specific, and formally well defined, issue. In the first part, we study the processes of self - organization and herding in the evolution of the stock market. The data analysis, carried out over the fluctuations of several international indices, shows an avalanche - like dynamics characterized by power laws and indicative of a critical state. Further evidence of criticality relates to the behaviour of the price index itself. In this case we observe a power law decline with superimposed embedded log - periodic oscillations which are possibly due to an intrinsic discrete scale invariance. A stochastic cellular automata, instead, is used to mimic an open stock market and reproduce the herding behaviour responsible for the large fluctuations observed in the price. The results underline the importance of the largest clusters of traders which, alone, can induce a large displacement between demand and supply and lead to a crash. The second part of the Thesis focuses on the role played by the complex network of interactions that is created among the elementary parts of the system itself. We consider, in particular, the influence of the so - called " scale - free " networks, where the distribution of connectivity follows a power law, on the antiferromagnetic Ising model and on a model of stochastic opinion formation. Novel features, not encountered on regular lattices, have been pointed out. In the former case a spin glass transition at low temperatures is present while, in the latter, the turbulent - like behaviour emerging from the model is found to be particularly robust against the indecision of the agents. The last part is left for a numerical investigation of an extremal dynamical model for evolution / extinction of species. We demonstrate how the mutual cooperation between them comes to play a fundamental role in the survival probability : a healthy environment can support even less fitted species. / Thesis (Ph.D.)--School of Chemistry and Physics, 2006.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 155-158).

Thesis (M.Arch.)--University of Detroit Mercy, 2009. / "24 April 2009." Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 109-112). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 109-112). Also available on the Internet.

Thesis (M. Sc.)--University of Hong Kong, 2002. / Includes bibliographical references.

Thesis (PH. D.)--Michigan State University. Electrical Engineering, 2008. / Title from PDF t.p. (viewed on Sept. 8, 2009) Includes bibliographical references (p. 202-210). Also issued in print.

Magister Philosophiae - MPhil / This study explored the learning experiences of black working class women in the context of the National Skills Development Strategy. The research focused firstly, on how the National Skills Development Strategy facilitated women's learning and secondly, what has helped and hindered their learning and how their learning experiences related to the literature on women's learning. / South Africa

The dissertation looks at the city as an emergent product of the lower-level activities of the city components. City components refer to the smaller elements which make up the fabric of a city like buildings, roads, inhabitants, cars etc. Lower-level activities refer to the interaction between these components, and define the consequential feedback into the city as a whole. An understanding of these aspects of emergence allows for the identification of tools and guidelines which, in turn, forms the basis for design and building performance criteria. / Dissertation (MArch(Prof))--University of Pretoria, 2008. / Architecture / unrestricted

Agrégation de l'enseignement supérieur, Orientation sciences / Thèse d'agrégation / info:eu-repo/semantics/nonPublished