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 45 for “"Differential Algebraic Equations"”.
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Applications and numerical investigation of differential-algebraic equations
Differential-algebraic equations (DAEs) result in many areas of science and engineer- ing. In this thesis, numerical methods for solving DAEs are compared for two prob- lems, energy-economic models and traffic flow models. An energy-economic model is presented based on the Hubbert model of oil …
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Approximation Methods for the Consistent Initialization of Differential-Algebraic Equations
The algebraic constraints in a system of differential-algebraic equations (DAEs) impose a consistency requirement on the initial values that can be difficult to satisfy. In this thesis the consistency requirement is characterized by a system of equations. An approximation method is introduced for …
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Theory and Application of a Class of Abstract Differential-Algebraic Equations
… and existence of solutions for ordinary differential-algebraic equations (DAEs). Because of the geometric and operator-theoretic aspects of this particular method, it can be extended to the case of infinite-dimensional abstract DAEs. For example, partial differential equations (PDEs) are …
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Approximations for Nonlinear Differential Algebraic Equations to Increase Real-time Simulation Efficiency
… of requiring the solution of a set of coupled differential algebraic equations (DAE). DAE's are not conducive to real-time implementation such as in a driving simulator, without a very expensive processing capability. The primary objective of this thesis is to show that multi-body models …
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Waveform relaxation methods for the simulation of systems of differential algebraic equations with applications to electric power systems
… terminals are kept intact, yielding a set of differential/algebraic equations (DAEs). In addition to power systems, systems of differential/algebraic equations arise in connection with singular perturbation, control theory, robot systems, and many other applications in the fields of mechanical …
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A modeling framework and toolset for simulation and characterization of the cochlea within the auditory system
… active nonlinear. These models are formulated as differential algebraic equations, and solved for impulse and tone excitations to determine responses. The solutions are mapped into tuning characteristics as a function of position within the cochlear partition. Objectives The central objective of …
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Optimal Linear Feedback Control for Incompressible Fluid Flow
… control is considered for large systems of differential algebraic equations arising from discretization of saddle point problems. Necessary conditions are derived by applying the Maximum Principle and have the form of constrained Riccati equations. We consider two approaches for solving the …
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Modellbasierte Diagnose auf Basis Differential-Algebraischer Systeme mit Nichtlinearen Kalman-Filtern
… This thesis considers the models formulated as Differential-Algebraic Equations (DAE) for the model-based diagnosis. <br /><br /> The foundation for the development of the diagnosis methods is the state estimation with nonlinear Kalman-filters. Consequently, the state estimation approaches as …
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Dynamic Security Assessment of Power Systems Using Trajectory Sensitivity Approach
… can easily handle complex models such as differential algebraic equations (DAE), discrete event coupled with DAE, and even hybrid systems. On the other hand, this approach suffers from the requirement of additional computation of the sensitivities. Nevertheless, this approach has provided …
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Generalized BDF methods applied to Hessenberg form DAEs
… study the numerical solution of Hessenberg form differential algebraic equations by variable stepsize generalized backward difference formulae (GBDF). GBDF methods of sufficiently high order are shown to converge for problems of index two, three, or four. The proof techniques developed are not …
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Reduced Order Methods for Large Scale Riccati Equations
… quadratic regulator (LQR) problem for partial differential equations (PDEs) leads to many computational challenges. The primary challenge comes from the fact that discretization methods for PDEs typically lead to very large systems of differential or differential algebraic equations. These …
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Dynamics and Control of Higher-order Nonholonomic Systems
… model for such systems is developed in terms of differential-algebraic equations defined on a higher-order tangent bundle. A number of control-theoretic properties such as nonintegrability, controllability, and stabilizability are presented. Higher-order nonholonomic systems are shown to be …
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Mathematical Tools for Discontinuous Dynamical Systems
Nonsmooth equations and discontinuous dynamical systems can be used to model systems in a variety of applications, including modeling of certain physical systems and optimization problems. However, theoretical results are somewhat limited for these classes of problems, restricting their use in …
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Estimating Uncertainties in the Joint Reaction Forces of Construction Machinery
… modeling stochastic systems for which the equations of motion are not available. The analysis targeted the reaction forces in joints of interest. The modeling approach developed in this thesis builds a foundation for determining the uncertainties in a Caterpillar 980G II wheel loader. The …
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Qualitative and Quantitative Investigation of Planar Multibody Dynamics Encompassing GSSSS Family of Algorithms - A Novel In-depth Look
… wide variety of time integration methods for the differential-algebraic equations (DAEs) inherent to these systems. The vast majority of these methods require refor- mulation of the natural index 3 equations of motion leading to additional computational cost and the need to control drift …
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Gas lift valve failure mode analysis and the design of a thermally-actuated positive-locking safety valve
… and gas lift valve geometry. A set of three differential algebraic equations of the system is solved to determine the system state. Gas lift valve, two-phase flow, and reservoir models are validated with well and experimental data. Sensitivity analysis is performed on the model and sensitive …
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Abordagem algébrico-diferencial na simulação unidimensional do escoamento bifásico em dutos
… performed instead by simultaneously solving all equations of change and constitutive models using established numerical methods devised for Differential-Algebraic Equations (DAE) systems. Through objective comparisons between this strategy and the finite-volume based technique, the DAE approach …
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Surface kinetics modeling of silicon oxide etching in fluorocarbon plasmas
… environment and simulator was used for solving differential algebraic equations that describes the surface kinetics. In the modeling, the effect of many variables were investigated including neutral and ion fluxes to the surface, sticking probabilities, surface composition, sputter etching …
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Biological Circuit Design via BioCAD Tools
… the gene protein reaction mappings, ordinary differential equations, differential algebraic equations and partial differential equations. In this thesis will be reported several experiments applied on Synthetic Biology, such as the design of the novel 1,4-butanediol synthetic pathway.
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