Thesis (M.S. in electrical engineering)--Washington State University, December 2009. / Title from PDF title page (viewed on Feb. 4, 2010). "School of Electrical Engineering and Computer Science." Includes bibliographical references (p. 52-53).

This thesis addresses the problem of how to examine a metabolic pathway and identify what are the key elements, specifically with respect to rate-limitation. The aim is to be able to analyze a pathway, identify the bottlenecks and implement genetic modifications to remove these bottlenecks. This is done by defining the system of interest and developing a predictive model using kinetic data. The model predictions can then be verified using fermentation data and genetic techniques to make the appropriate changes for improved performance. The test system chosen for this study was the TOL meta-cleavage pathway for the degradation of benzoate. This system was chosen on the basis of the application of pathway engineering principles to other systems. The modelling strategy and software was developed using principles from metabolic control theory and biochemical systems theory. By applying this to the TOL pathway using kinetic data, the control coefficients for the pathway were obtained as well as the system parameters required for the optimization of the pathway. The simulated results obtained from this model must be validated by experiment. Errors can arise both from incorrect assumptions in the model and from the fact that the kinetic data taken from individual in vitro experiments may not be applicable to the in vivo system. The effect of the presence of the TOL pathway on the behaviour of E.coli JM107 during fermentation was investigated and the transient concentration data necessary to identify the bottlenecks in the pathway measured. This data is then used to calculate the flux control coefficients for the TOL pathway. The predictive results were verified by the fermentation data which identified the first two enzymes in the pathway as having significant flux control coefficients. This final chapter also addresses the issue of flux analysis, that is, the calculation of the fluxes in the system to determine where fluxes to unwanted by-products occur and to indicate points of control. A graphical user interface is used to provide a user-friendly and intuitive means of building and customising metabolic pathways which can then be interfaced with instrumentation to provide on-line flux analysis.

Thesis (M.S.)--Ohio University, August, 1995. / Title from PDF t.p.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (p. 149-167) Also available in print.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 62-63). Also available via the Internet.

No description available.

Permanent magnet synchronous motors are finding ever increasing use in hybrid and electric vehicles. This thesis develops a new control strategy for Permanent Magnet Synchronous Motors (PMSMs) to reduce the motor and inverter losses compared to conventional control techniques. The strategy utilises three common control modes for PMSMs; brushless DC with 120°E conduction, brushless DC with 180°E conduction, and brushless AC control. The torque and power output for each control mode is determined for an example motor system using a three phase axial flux YASA motor and an IGBT inverter. The loss components for the motor and inverter are also estimated using a combination of analytical and simulation techniques and results are then validated against experimental measurements. Efficiency maps for each control mode have been used to determine an optimal mode utilisation strategy, which minimises the total system losses and maximises the available motor torque output. The proposed control strategy switches between the three control modes without interruption of motor torque to maximise the system efficiency for the instantaneous operating speed and demanded torque output. The benefits of the new strategy are demonstrated using an example vehicle over a simulated drive cycle. This yields a 10% reduction in losses compared to conventional brushless AC control.

No que segue, propõe-se uma classe de sistemas robóticos multi-corpos, cujos corpos componentes estão fisicamente acoplados através de juntas rotativas ativas. Os sistemas da classe considerada possuem mobilidade irrestrita no espaço plano uma vez que propulsores distribuídos ao longo dos corpos do sistema. A modelagem dinâmica destes sistemas é apresentada sob as abordagens Hamiltoniana e Lagrangiana da mecânica analítica. A descrição destes métodos de modelagem, assim como os modelos por eles obtidos, é realizada com ênfase na interpretação geométrica da matemática envolvida. Alguns exemplos de parametrizações do espaço de fase do sistema são discutidos e exemplos de modelagem em função destas parametrizações são obtidos. Ademais, alguns critérios de análise de controlabilidade não-linear são revisados e aplicados aos modelos do sistema com a estrutura de entradas considerada. Alguns casos de estabilização da classe de sistemas são também discutidos. Resultados de simulação de estabilização são obtidos para sistemas através de estudos de casos. Sistemas completamente controlados no espaço de estados podem ser linearizados através de uma técnica de linearização por realimentação e estabilizados com uma realimentação de estados. Para os sistemas cuja controlabilidade é deficiente, propõe-se a modificação de um método de controle de sistemas sub-atuados e uma lei de controle por realimentação é obtida pela teoria de estabilidade de Lyapunov. A classe de sistemas aqui discutida possui grande potencial de aplicação nos ambientes espacial e submarino. / In the following, a class of multi-body robotic systems is proposed in which its system component bodies are physically coupled by active rotating joints. The systems belonging to the proposed class have unrestricted mobility on the plane since thrusters are distributed along the system. System dynamical modeling is obtained through the analytic mechanical Hamiltonian and Lagrangian methods. The presentation of these methods, as well as the dynamical models obtained by them, is realized with an emphasis in the geometrical interpretation of the corresponding mathematics. A few different system phase space parameterizations approaches are discussed and modeling examples are presented under these parameterizations. Additionally, some nonlinear controllability analysis criteria are reviewed and applied to system dynamical models composed by the input structure mentioned above. A few stabilization case studies for the class of systems are also discussed and simulation results are presented. Totally controlled systems in the phase space can be linearized by feedback linearization techniques and stabilized through a state feedback. For partially controllable systems a modification of a stabilization method for under-actuated systems is proposed which renders feedback control via Lypunov stability theory. The class of systems discussed has great potential for space and underwater applications.

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Divan, Deepakraj M.; Committee Member: Begovic, Miroslav M.; Committee Member: Brown, Marilyn; Committee Member: Harley, Ronald G.; Committee Member: Wolf, Wayne H. Part of the SMARTech Electronic Thesis and Dissertation Collection.

No que segue, propõe-se uma classe de sistemas robóticos multi-corpos, cujos corpos componentes estão fisicamente acoplados através de juntas rotativas ativas. Os sistemas da classe considerada possuem mobilidade irrestrita no espaço plano uma vez que propulsores distribuídos ao longo dos corpos do sistema. A modelagem dinâmica destes sistemas é apresentada sob as abordagens Hamiltoniana e Lagrangiana da mecânica analítica. A descrição destes métodos de modelagem, assim como os modelos por eles obtidos, é realizada com ênfase na interpretação geométrica da matemática envolvida. Alguns exemplos de parametrizações do espaço de fase do sistema são discutidos e exemplos de modelagem em função destas parametrizações são obtidos. Ademais, alguns critérios de análise de controlabilidade não-linear são revisados e aplicados aos modelos do sistema com a estrutura de entradas considerada. Alguns casos de estabilização da classe de sistemas são também discutidos. Resultados de simulação de estabilização são obtidos para sistemas através de estudos de casos. Sistemas completamente controlados no espaço de estados podem ser linearizados através de uma técnica de linearização por realimentação e estabilizados com uma realimentação de estados. Para os sistemas cuja controlabilidade é deficiente, propõe-se a modificação de um método de controle de sistemas sub-atuados e uma lei de controle por realimentação é obtida pela teoria de estabilidade de Lyapunov. A classe de sistemas aqui discutida possui grande potencial de aplicação nos ambientes espacial e submarino. / In the following, a class of multi-body robotic systems is proposed in which its system component bodies are physically coupled by active rotating joints. The systems belonging to the proposed class have unrestricted mobility on the plane since thrusters are distributed along the system. System dynamical modeling is obtained through the analytic mechanical Hamiltonian and Lagrangian methods. The presentation of these methods, as well as the dynamical models obtained by them, is realized with an emphasis in the geometrical interpretation of the corresponding mathematics. A few different system phase space parameterizations approaches are discussed and modeling examples are presented under these parameterizations. Additionally, some nonlinear controllability analysis criteria are reviewed and applied to system dynamical models composed by the input structure mentioned above. A few stabilization case studies for the class of systems are also discussed and simulation results are presented. Totally controlled systems in the phase space can be linearized by feedback linearization techniques and stabilized through a state feedback. For partially controllable systems a modification of a stabilization method for under-actuated systems is proposed which renders feedback control via Lypunov stability theory. The class of systems discussed has great potential for space and underwater applications.