Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 38 for “"dynamical systems theory"”.
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Mindcraft: a Dynamical Systems Theory of Cognition
<p>This dissertation develops a theory of cognition, driven by recent developments in the electrophysiological investigation of the neuronal mechanisms that support adaptive behavior. In the first chapter, I situate the theory in the conceptual landscape of the philosophy of mind, distinguishing …
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Scientific Machine Learning for Dynamical Systems: Theory and Applications to Fluid Flow and Ocean Ecosystem Modeling
Complex dynamical models are used for prediction in many domains, and are useful to mitigate many of the grand challenges being faced by humanity, such as climate change, food security, and sustainability. However, because of computational costs, complexity of real-world phenomena, and limited …
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Learning Environmental Models With Multi-Robot Teams Using A Dynamical Systems Approach
… methods for representing the environment as a dynamical system with machine learning techniques. Specifically, we formulate machine learning methods that lend to data-driven modeling of the phenomena. The data-driven modeling explicitly leverages theoretical foundations of dynamical systems …
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Deterministic transport: from normal to anomalous diffusion
… the important questions in statistical physics. Dynamical systems theory play a key role in a resent advance in this direction. Offering relatively simple models which are easy to study, dynamical systems theory became a standard branch of modern nonequilibrium statistical physics. In the present …
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Center Manifold Dynamics in Randomly Coupled Oscillators and in Cochlea
<p>In dynamical systems theory, a fixed point of the activity is called nonhyperbolic if the linearization of the system around the fixed point has at least one eigenvalue with zero real part. The center manifold existence theorem guarantees the local existence of an invariant subspace of the …
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Natural and artificial orbits around the Martian moon Phobos
… the analytical and numerical methodologies of dynamical systems theory. These techniques exploit the improved description of the natural dynamics, enabled by the extended model, to provide low-cost guidance trajectories, that minimize the fuel consumption and extend the mission range. In …
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Systems evolution: the conceptual framework and a formal model
… addresses to some of the fundamental problems in systems science.T he aim of this study is to: (1) provide a general conceptual framework for systems evolution; (2) develop a formal model for evolving systems based on dynamical systems theory; (3) analyse the evolving behaviour of various systems …
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Geometrical and nonperturbative aspects of low dimensional field theories
… on solitons in low-dimensional classical field theory. We begin by reviewing the geometrical setting of he nonlinear ơ-model and demonstrate the integrability of the theory in two-dimensions on a symmetric target manifold. After reviewing the construction of soliton solutions in the 0(3) ơ-model …
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Laboratory investigations of a chaotic flow using braid theory
… flows has been a long-standing challenge in dynamical systems theory, with applications to industrial and natural flows. The detection of Lagrangian structures that stay coherent over time helps gain insight into the evolution of a system's dynamics and the fate of transport. Whereas most …
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A dynamical systems approach to the study of local phenomena in fluid flows
… in the utilization of nonlinear tools from dynamical systems theory. In fluid dynamics, prominent examples are Koopman eigenfunctions (through dynamic mode decomposition) and spectral submanifolds. Due to their immense popularity, both of these techniques have been studied extensively, to …
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Nonlinear machine learning of macromolecular folding and self-assembly
… for studying biological, physical and chemical systems at the atomistic scale. In this thesis, I report several applications of molecular dynamics simulation and machine learning in the study of the macromolecular folding and assembly. In the first aspect, I employ molecular simulation and …
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Mixing enhancement by dual speed rotating stirrer
… of passive fluid particles is considered using dynamical systems theory. The bifurcation diagram reveals the presence of degenerate fixed points and homoclinic/heteroclinic orbits, whose nature varies for different parameter values. By considering an initially concentrated set of marker …
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Spacecraft trajectory design utilizing resonance orbits in a hybrid optimal control framework
… this tool has shown the ability to use other key dynamical structures of the circular restricted three-body problem (e.g. Euler-Lagrange point orbits and their invariant manifolds) within the same automated global optimization framework to produce low-energy trajectory solutions. This work …
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Nonlinear thermoacoustic oscillations of a ducted laminar premixed flame
… oscillation in a nonlinear system. Nonlinear systems can have quasi-periodic and chaotic oscillations. This thesis examines the different types of oscillation in a numerical model of a ducted premixed flame, the bifurcations that lead to these oscillations and the influence of external forcing …
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Nonlinear Dynamics, Synchronisation and Chaos in Coupled FHN Cardiac and Neural Cells
Physiological systems are amongst the most challenging systems to investigate from a mathematically based approach. The �eld of mathematical biology is a relatively recent one when compared to physics. In this thesis I present an introduction to the physiological aspects needed to gain access to …
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A dynamical-systems approach to understanding turbulence in plane Couette flow
<p>Dynamical systems theory is used to understand the dynamics of low-dimensional spatio-temporal chaos. Our research aimed to apply the theory to understanding turbulent fluid flows, which could be thought of as spatio-temporal chaos in a very-high dimensional space. The theory explains a system's …
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Designing Transfers Between Earth-Moon Halo Orbits Using Manifolds and Optimization
… space, identifying efficient transfers in the dynamical environment characterized by the Circular Restricted Three-Body Problem (CR3BP) will be especially important, both now and in the immediate future. The focus of this thesis is to develop a methodology that can be used to identify a valid …
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Resilience Engineering via Bifurcation and Ecological Network Analysis: Demonstrated in an Electric Power Case Study
<p>Modern systems are increasingly complex, interconnected cyber-physical systems that combine digital controls with physical infrastructure. This integration, along with the constant introduction of new technologies and actors into the network, enables reliable operation but introduces …
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Identifying and Characterizing Transition Cells in Developmental Processes from scRNA-Seq Data
… differential equations (SDEs). Based on dynamical systems theory, I developed a statistical approach, CellTran, which leverages pairwise gene expression correlation coefficients to infer cell state transitions. I validated this method using simulation datasets generated by SERGIO and …
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Integrability, localisation and bifurcation of an elastic conducting rod in a uniform magnetic field
… is investigated using modern techniques from dynamical systems theory. The Kirchhoff equations, which describe the static equilibrium equations of a geometrically exact rod under end tension and moment are extended by incorporating the evolution of a fixed external vector (in the direction of …
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