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 158 for “"Model reduction"”.
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Sensitivity Enhanced Model Reduction
… of coupling sensitivity analysis to the reduced model in order to increase the accuracy of a proper orthogonal decomposition (POD) basis across a wider range of parameters. Various techniques based on polynomial interpolation and basis alteration are compared. These techniques are performed on a …
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Model Reduction Using Semidefinite Programming
In this thesis model reduction methods for linear time invariant systems are investigated. The reduced models are computed using semidefinite programming. Two ways of imposing the stability constraint are considered. However, both approaches add a positivity constraint to the program. The input to …
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Model reduction in physical domain
Modeling is an essential part of the analysis and the design of dynamic systems. Contemporary computer algorithms can produce very detailed models for complex systems with little time and effort. However, over complicated models may not be efficient. Therefore, reducing a model to a more manageable …
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Model Reduction of Power Networks
… large-scale systems have high dimensional models that are computationally expensive to simulate especially in real time applications, stability analysis, and control design. Model order reduction (MOR) tackles this issue by approximating these high dimensional models with reduced …
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Krylov Projection Methods for Model Reduction
… focuses on efficiently forming reduced-order models for large, linear dynamic systems. Projections onto unions of Krylov subspaces lead to a class of reduced-order models known as rational interpolants. The cornerstone of this dissertation is a collection of theory relating Krylov projection …
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Convex optimization methods for model reduction
Model reduction and convex optimization are prevalent in science and engineering applications. In this thesis, convex optimization solution techniques to three different model reduction problems are studied.Parameterized reduced order modeling is important for rapid design and optimization of …
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Model reduction for Hidden Markov models
… dynamical systems, finite alphabet Hidden Markov Models and Jump Linear Systems with finite parameter space. The reduction algorithms employ convex optimization and numerical linear algebra tools and do not pose any structural requirements on the systems at hand. In the Jump Linear Systems case, a …
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Inexact Solves in Interpolatory Model Reduction
Dynamical systems are mathematical models characterized by a set of differential or difference equations. Due to the increasing demand for more accuracy, the number of equations involved may reach the order of thousands and even millions. With so many equations, it often becomes computationally …
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Control-Oriented Model Reduction for Parabolic Systems
… Arbeit werden effiziente Implementierungen von Modellreduktionsverfahren für lineare, zeitinvariante Kontrollsysteme entwickelt. Modellreduktion spielt eine wichtige Rolle in der Simulation, Kontrolle und Optimierung von komplexen, dynamischen Systemen, wie sie bei der Modellierung vieler …
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Model Reduction for Linear Time-Varying Systems
The thesis treats model reduction for linear time-varying systems. Time-varying models appear in many fields, including power systems, chemical engineering, aeronautics, and computational science. They can also be used for approximation of time-invariant nonlinear models. Model reduction is a topic …
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Blackbox Stencil Interpolation Method for model reduction
Model reduction often requires modifications to the simulation code. In many circumstances, developing and maintaining these modifications can be cumbersome. Non-intrusive methods that do not require modification to the source code are often preferred. This thesis proposed a new formulation of …
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Model Reduction of Nonlinear Fire Dynamics Models
… and multi-physics nature of the mathematical models for fires, current numerical models require too much computational effort to be useful in design and real-time decision making, especially when dealing with fires over large domains. To reduce the computational time while retaining the …
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Model Reduction of Linear Time-Periodic Dynamical Systems
Few model reduction techniques exist for dynamical systems whose parameters vary with time. We have particular interest here in linear time-periodic dynamical systems; we seek a structure-preserving algorithm for model reduction of linear time-periodic (LTP) dynamical systems of large scale that …
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Parameter Dependent Model Reduction for Complex Fluid Flows
… physical systems, using very large numerical models for the solution of a system of parameter dependent partial differential equations (PDEs) is usually intractable. Surrogate models are used to provide an approximation to the high fidelity models while being computationally cheaper to …
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On Modeling and Nonlinear Model Reduction in Automotive Systems
… and hand-tuning of control parameters. Model based control design is a promising approach to reduce costs and development time. In this process low complexity models are essential and model reduction methods are very useful tools. This thesis combines the areas of modeling and model …
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Model Reduction and Domain Decomposition Methods for Uncertainty Quantification
… of Chapters 2, 3, and 4. Chapter 2 introduces a model reduction strategy that is used in the context of elasticity imaging to infer the presence of an inclusion embedded in a soft matrix, mimicking tumors in soft tissues. The method relies on Polynomial Chaos (PC) expansions to build a dictionary …
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Kinetic model reduction using integer and semi-infinite programming
… work an optimization-based approach to kinetic model reduction was studied with a view to generating reduced-model libaries for reacting-flow simulations. A linear integer formulation of the reaction elimination problem was developed in order to allow the model reduction problem to be solved …
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