published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

A fundamental question in Complexity Science is how numerous dynamic processes coordinate with each other on multiple levels of description to form a complex whole - a multiscale coordinative structure (e.g. a community of interacting people, organs, cells, molecules etc.). This dissertation includes a series of empirical, theoretical and methodological studies of rhythmic coordination between multiple agents to uncover dynamic principles underlying multiscale coordinative structures. First, a new experimental paradigm was developed for studying coordination at multiple levels of description in intermediate-sized (N = 8) ensembles of humans. Based on this paradigm, coordination dynamics in 15 ensembles was examined experimentally, where the diversity of subjects movement frequency was manipulated to induce di erent grouping behavior. Phase coordination between subjects was found to be metastable with inphase and antiphase tendencies. Higher frequency diversity led to segregation between frequency groups, reduced intragroup coordination, and dispersion of dyadic phase relations (i.e. relations at di erent levels of description). Subsequently, a model was developed, successfully capturing these observations. The model reconciles the Kuramoto and the extended Haken-Kelso-Bunz model (for large- and small-scale coordination respectively) by adding the second-order coupling from the latter to the former. The second order coupling is indispensable in capturing experimental observations and connects behavioral complexity (i.e. multistability) of coordinative structures across scales. Both the experimental and theoretical studies revealed multiagent metastable coordination as a powerful mechanism for generating complex spatiotemporal patterns. Coexistence of multiple phase relations gives rise to many topologically distinct metastable patterns with di erent degrees of complexity. Finally, a new data-analytic tool was developed to quantify complex metastable patterns based on their topological features. The recurrence of topological features revealed important structures and transitions in high-dimensional dynamic patterns that eluded its non-topological counterparts. Taken together, the work has paved the way for a deeper understanding of multiscale coordinative structures. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Lee Joy Yan Agatha. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves [112]-114). / Text in English; abstracts in English and Chinese. / Lee Joy Yan Agatha. / Abstract --- p.ii / Acknowledgement --- p.iii / Contents --- p.iv / List of Figures --- p.viii / List of Tables --- p.xii / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- The Transfer Integral Equation Method --- p.3 / Chapter 2.1 --- The System --- p.3 / Chapter 2.1.1 --- The Hamiltonian --- p.4 / Chapter 2.1.2 --- The length parameter --- p.5 / Chapter 2.1.3 --- The temperature parameter --- p.5 / Chapter 2.2 --- The Transfer Integral Equation --- p.6 / Chapter 2.2.1 --- The partition function --- p.6 / Chapter 2.2.2 --- The transfer integral equation --- p.6 / Chapter 2.2.3 --- The pseudo-Schrodinger equation approximation --- p.7 / Chapter 2.2.4 --- Distribution function of the displacements --- p.9 / Chapter 2.3 --- The Thermodynamics --- p.10 / Chapter 2.3.1 --- Internal energy and heat capacity --- p.10 / Chapter 2.3.2 --- Displacement fluctuation --- p.12 / Chapter 2.3.3 --- Displacement correlation function --- p.12 / Chapter Chapter 3. --- The Φ4 Chain --- p.14 / Chapter 3.1 --- Soliton In The Chain --- p.15 / Chapter 3.1.1 --- Kink soliton and antikink soliton --- p.15 / Chapter 3.1.2 --- Energy of a static kink --- p.18 / Chapter 3.2 --- Low Temperature WKB Approximation for the Φ4 Chain --- p.20 / Chapter 3.2.1 --- The ground state energy ε0 and tunneling-splitting contribution --- p.20 / Chapter 3.2.2 --- First order WKB approximation of ΨRo( φ) --- p.22 / Chapter 3.2.3 --- Second order WKB wavefunction ΨRo( φ)） --- p.26 / Chapter 3.2.4 --- Third order WKB wavefunction for ΨRo( φ) --- p.27 / Chapter 3.3 --- Thermodynamics --- p.28 / Chapter 3.3.1 --- Ground state energy ε0 and wavefunction Ψo( φ) --- p.28 / Chapter 3.3.2 --- Internal energy and heat capacity --- p.33 / Chapter 3.3.3 --- Displacement correlation function --- p.36 / Chapter Chapter 4. --- Other Nonlinear Klein-Gordon Models --- p.42 / Chapter 4.1 --- The φ8 Chain --- p.42 / Chapter 4.1.1 --- The potential --- p.42 / Chapter 4.1.2 --- The ground state energy εo and wavefunction Ψo( φ) --- p.44 / Chapter 4.1.3 --- Internal energy and heat capacity --- p.49 / Chapter 4.1.4 --- Displacement correlation function cyy(n) --- p.51 / Chapter 4.2 --- The Gaussian-Double-Well Chains --- p.53 / Chapter 4.2.1 --- The potential --- p.53 / Chapter 4.2.2 --- The ground state energy εo and wavefunction ψo --- p.55 / Chapter 4.2.3 --- Internal energy and heat capacity --- p.58 / Chapter 4.2.4 --- Displacement correlation function cyy(n) --- p.59 / Chapter 4.3 --- Comparison Between Different NKG Models --- p.61 / Chapter 4.3.1 --- The potentials --- p.61 / Chapter 4.3.2 --- Ground state energy εo and wavefunction ψo(ψ) --- p.65 / Chapter 4.3.3 --- Internal energy and heat capacity --- p.68 / Chapter 4.3.4 --- Displacement fluctuation --- p.70 / Chapter 4.3.5 --- Displacement correlation function cyy(n) --- p.71 / Chapter 4.4 --- Linear Response of a NKG Chain to a Static Perturbing Field --- p.75 / Chapter 4.4.1 --- The external perturbing field --- p.75 / Chapter 4.4.2 --- The linear response --- p.75 / Chapter 4.4.3 --- Linear response of an array of weakly coupled NKG chains --- p.80 / Chapter Chapter 5. --- Quantum Corrections --- p.86 / Chapter 5.1 --- The Effective Potential --- p.86 / Chapter 5.1.1 --- The smearing parameter --- p.86 / Chapter 5.1.2 --- The effective potential --- p.88 / Chapter 5.2 --- Quantum Corrections on Thermodynamics --- p.90 / Chapter 5.2.1 --- The ground state energy εo and wavefunction ψo(ψ) --- p.90 / Chapter 5.2.2 --- The heat capacity --- p.94 / Chapter 5.2.3 --- Displacement correlation function and displacement fluctuation --- p.97 / Chapter Chapter 6. --- Conclusion --- p.103 / Appendix A. Infinite-Square-Well Basis Diagonalization --- p.105 / Appendix B. Oscillator Basis Diagonalization --- p.110 / Bibliography --- p.112

Wang Dan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 128-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Orientador: Antonio Roberto Balbo / Banca: Guilherme Guimarães Lage / Banca: Leonardo Nepomuceno / Resumo: Em um problema de despacho econômico, objetiva-se determinar a geração de potência ativa das umidades geradoras, de modo que a demanda seja atendida e os custos dos combustíveis utilizados na geração sejam minimiados, ao mesmo tempo que as restrições de operação do sistema sejam atendidas. A função objetivo de custo deste problema pode ser modelada de diversas maneiras, porém uma forma mais realista da mesma inclui os efeitos dos pontos de carregamento de válvula. Quando os pontos de carregamento de válvula são considerados, a função objetivo se torna não-diferenciável, o que impossibilita a aplicação direta de métodos clássicos de otimização na resolução do problema. Por este motivo, a maioria dos trabalhos disponíveis na literatura para a resolução do Problema de Despacho Econômico com Ponto de Carregamento de Válvula (PDE-PV) são baseados em heurísticas. Neste trabalho, apresenta-se um método Primal-Dual Previsor-Corretor Barreira Logarítmica Modificada (PDPCBLM) associado a uma estratégia de correção de inércia de suavização hiperbólica para a resolução de problemas de despacho econômico com ponto de carregamento de válvula. A estratégia de correção de inércia visa garantir a convergência do método para mínimos locais do problema. A técnica de suavização hiperbólica, quando aplicada ao PDE-PV e suas variantes - o Problema de Despacho Econômico com representação das Perdas e Ponto de Carregamento de Válvula (PDE-PPV) e o Problema de Despacho Econômico com Ponto de Carregamento de Válvula e Representação da Transmissão (PDE-PV-RT) -, possibilita a utilização do método PDPCBLM para sua resolução. Uma implementação desses métodos realizada em Matlab, mostra que tais métodos são eficientes na resolução do PDE-PV e suas variantes, obtendo resultados de boa qualidade, quando comparados aos disponíveis na literatura / Abstract: In the economic dispatch problem, the objective is to determine the active power output of the generating units in order to supply the demand and minimize the fuel costs associated with power generation, while talking into account system operational constraints. The cost objective function of this problem can be defined in many different ways, but a more realistic form of representation includes valve-point load effects. When valve-point load effects are considered, the objective function becomes non-differentiable, which precludes the direct application of classical optimization methods to solve the problem. For this reason, most proposals to solve the Economic Dispatch Problem with Valve-Point Load Effects (EDP-VPE) available in the literature are based on heuristics. In this work, we present a Primal-Dual Predictor-Corrector Modified Logarithmic Barrier method (PDPCMLB) associated with an inertia correction strategy and a hyperbolic smoothing technique to solve economic dispatch problems with valve-point load effects. The purpose of the inertia correction is to ensure that the proposed method converges to a local minimum of the problem. The hyperbolic smoothing technique, when applied to the EDP-VPE and its variations - the Economic Dispatch Problem with Loss Representation and Valve-Point Load Effects (EDP-LVPE) and the Network Constrained Economic Dispach with Valve-Point Load Effects (NC-EDP-VPE) -, allows the use of the PDPCMLB method to solve it. An implementation of these methods, performed in Matlab, shows that they are efficient to solve the EDP-VPE and its variations, obtaining good results whem compared to athers available in the literature / Mestre

In this thesis, the critical phenomenon in Berry curvature of nonlinear systems that occurs at phase boundaries is described by using the Bogoliubov excitation of the semiquantal dynamics. Its is shown that when the critical boundary in the parameter space is crossed, the nonlinear geometric phase of the Bogloubov excitations surrounding the elliptic fixed points experiences non-analytic behavior. / 在本論文，我們利用半古典動力學的博戈留波夫激發研究非線性系統的貝里曲率在相邊界上出現的臨界現象。結果顯示，當參數空間中的臨界曲面被越過，環繞橢圓不動點的博戈留波夫激發的非線性幾何相位發生非解析行為。 / Kam, Chon Fai = 非線性系統的貝里曲率 / 甘駿暉. / Thesis M.Phil. Chinese University of Hong Kong 2014. / Includes bibliographical references (leaves 49-56). / Abstracts also in Chinese. / Title from PDF title page (viewed on 18, October, 2016). / Kam, Chon Fai = Fei xian xing xi tong de Beili qu lu / Gan Junhui. / Detailed summary in vernacular field only.

Zhong, Renxin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 107-114). / Abstracts in English and Chinese. / Abstract --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Non-Minimum Phase Nonlinear Systems --- p.1 / Chapter 1.2 --- Robust Output Regulation Problem --- p.4 / Chapter 1.3 --- Global Robust Output Regulation for Non-Minimum Phase Nonlinear Systems in Lower Triangular Form --- p.6 / Chapter 1.4 --- Rotational/Translational Actuator System --- p.8 / Chapter 1.5 --- Organization and Contributions --- p.8 / Chapter 2 --- Global Robust Output Regulation for Non-Minimum Phase Non-linear Systems in Lower Triangular Form --- p.10 / Chapter 2.1 --- Introduction --- p.10 / Chapter 2.2 --- Assumptions and Preliminaries --- p.12 / Chapter 2.3 --- Solvability Conditions --- p.17 / Chapter 2.4 --- Numerical Examples --- p.19 / Chapter 2.5 --- Concluding Remarks --- p.46 / Chapter 3 --- Global Robust Output Regulation for A Class of Non-Minimum Phase Nonlinear Systems by Output Feedback Control --- p.47 / Chapter 3.1 --- Introduction --- p.48 / Chapter 3.2 --- Assumptions and Preliminaries --- p.49 / Chapter 3.3 --- Reduced order observer design --- p.56 / Chapter 3.4 --- Stabilization of x system --- p.59 / Chapter 3.5 --- "Interconnection of the n,z,ζ,x subsystems and small gain condition" --- p.63 / Chapter 3.6 --- Numerical example --- p.67 / Chapter 3.7 --- Conclusion --- p.76 / Chapter 4 --- Robust output regulation for the nonlinear benchmark problem via output feedback --- p.77 / Chapter 4.1 --- Introduction --- p.78 / Chapter 4.2 --- Disturbance rejection problem of the RTAC system by output feedback control --- p.79 / Chapter 4.3 --- Robust Disturbance rejection problem of the RTAC system by output feedback --- p.88 / Chapter 4.4 --- Conclusion --- p.98 / Chapter 5 --- Conclusion --- p.103 / List of Figures --- p.105 / Bibliography --- p.107 / Biography --- p.115

This project discusses the use of System Identification for Smart Maintenance. System Identification is the process of finding a mathematical model of a system using empirical data. The mathematical model can then be used to detect and predict the maintenance needs, which is considered as Smart Maintenance. Smart maintenance strategies have gained pretty much importance recently, since it contributes to economically sustainable production. This project uses the LAVA-framework, proposed in [1] for non-linear system identification, which has the capability of explaining the dynamics of the system very well, and at the same time follows the principle of parsimony. A nominal model is first identified using data from a system that operates under normal operating conditions, then the identified nominal model is used to detect when the system starts to deviate from normal behavior, and these deviations indicate the deteriorations in the system. Furthermore, a new Multiple Model Method which is developed in [2] using the similar idea from LAVA, is applied on the large data set of a system that operates on separate batches and units, which identifies individual model for each batch and unit, which is then used to detect the deficient units or batches and changes in the system behavior. Finally, the proposed methods are applied to two different real world industrial cases; a Heat exchanger and a Wood Moulder Machine. In the first, the purpose is to detect the dirt in a Heat Exchanger, and in the second, the goal is to detect when the tool in a Wood Moulder Machine needs to be changed.

Abstract not available