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.
Results
Showing 1 to 20 of 115 for “"Iterative methods"”.
-
Efficient Iterative Methods for Saddle Point Problems
This thesis investigates efficient iterative methods for a type of saddle-point problem, namely the generalized Stokes problem, which arises frequently in the simulation of time-dependent Navier-Stokes equations for incompressible fluid flow. These systems are indefinite due to a set of linear …
-
Acceleration of Iterative Methods for Markov Decision Processes
… such problems. There are several standard methods for finding optimal or approximately optimal policies for MDP. Approaches widely employed to solve MDP problems include value iteration and policy iteration. Although simple to implement, these approaches are, nevertheless, limited in the …
-
Preconditioned iterative methods on virtual shared memory machines
… emphasis is laid upon how best to optimize iterative Krylov subspace methods using domain decomposition preconditioning. The domain decomposition preconditioner used was developed by J. H. Bramble, J. E. Pasciak, and A. H. Schatz. The Krylov subspace method used was the conjugate gradient …
-
Forward-backward heat equations and analysis of iterative methods
Contains fulltext : mmubn000001_209006145.pdf (Publisher’s version ) (Open Access)
-
The Performance of Preconditioned Iterative Methods in Computational Electromagnetics
… of the resulting matrix equation. By using iterative algorithms, the analysis of scatterers that are an order of magnitude larger electrically may be feasible.
-
Scalable Gaussian Processes: Advances in Iterative Methods and Pathwise Conditioning
… focuses on the powerful combination of iterative methods and pathwise conditioning to develop methodological contributions which facilitate the use of Gaussian processes in modern large-scale settings. By combining these two techniques synergistically, expensive computations are …
-
A study of iterative methods on forward and inverse scattering problems
Iterative methods are suitable for solving large-size problems in the electromagnetic and acoustic wave scattering. Both the conjugate gradient and bi-conjugate gradient methods combined with the fast Fourier transform (CGFFT and BiCGFFT) are employed as efficient solvers in forward and inverse …
-
Iterative methods, combinatorial optimization, and linear programming beyond the universal barrier
In this thesis we consider fundamental problems in continuous and combinatorial optimization that occur pervasively in practice and show how to improve upon the best known theoretical running times for solving these problems across a broad range of parameters. Using and improving techniques from …
-
Sparse approximations, iterative methods, and faster algorithms for matrices and graphs
This thesis aims to advance our algorithmic understanding of some of the most fundamental objects in computer science: graphs and matrices. Specifically, on one hand, we develop a broad set of sampling techniques that yield better (sparser) approximations of these objects and do so more …
-
Preconditioned iterative methods for highly sparse, nonsymmetric, unstructured linear algebra problems
… sparse, nonsymmetric, and unstructured. Several iterative methods which are applicable to nonsymmetric and indefinite problems are applied to a suite of test problems derived from simulations of actual bipolar circuits and to a viscous flow problem. Methods tested include Craig’s method, …
-
A Class of Robust and Efficient Iterative Methods for Wave Scattering Problems
… towards the development of numerically efficient iterative techniques for the solution of boundary integral equation formulations of time harmonic scattering problems. The primary result of this effort has been the development of several advanced numerical techniques which enable the dense …
-
Accelerated stationary iterative methods for the numerical solution of electromagnetic wave scattering problems
… this work is to contribute to the development of iterative solvers applied to the method of moments solution of electromagnetic wave scattering problems. In recent years there has been much focus on current marching iterative methods, such as Gauss-Seidel and others. These methods attempt to march …
-
Iterative Methods for the Reconstruction of Tomographic Images with Unconventional Source-detector Configurations
… the short term. We implemented the Van Cittert iterative technique for the reconstruction of images from projections. The thesis discusses a number of variations on the algorithm, such as the use of the Conjugate Gradient Method, several choices for the initial guess, and the incorporation of a …
-
A class of batch-iterative methods for the equalization of intersymbol interference channels
… interference (ISi) channels in a batch-iterative fashion. The iterated-decision or multipass equalizer uses symbol decisions made during the previous iteration to cancel out both precursor and postcursor ISi during the current iteration. With each successive pass of the equalizer, the …
-
Optimum Semi-Iterative Methods for the Solution of Any Linear Algebraic System With a Square Matrix
… T. A. Manteuffel developed a method for the iterative solution of a non-symmetric linear system, Ax = b, when the eigenvalues have positive real parts. The iterative parameters are reciprocals of the roots of a scaled and translated Chebyshev polynomial and depend upon an ellipse enclosing …
-
On the Implementation and Performance of Iterative Methods for Computational Electromagnetics (Scattering, Moment-Method, Conjugate-Gradient)
… matrix equation. The use of an iterative algorithm to solve the matrix equation sometimes results in a considerable savings in computer memory requirements. For a fixed amount of computer memory, this approach permits the analysis of scatterers that are an order of magnitude …
-
Design and deploy : iterative methods in adapting mobile technologies for data acquisition : a case study in St. Louis, Missouri
Advancements in mobile technology provide the opportunity to explore not only how data gathering (e.g., surveying) can be eased through digital input mechanisms, but also how such devices can bring new resolution to data gathered. This thesis covers the development history of an Android-based …
-
Three solution techniques for the orbital intercept problem including oblateness effects
Three methods for solving the orbital intercept problem in the presence of an oblate earth are presented. Both iterative and direct approaches for solving the problem were compared in the bases of computational time and relative accuracy of the results. The two iterative methods were found to agree …
-
Iterative Solution Methods for Reduced-Order Models of Parameterized Partial Differential Equations
… many unknowns whose solution via traditional methods can be expensive. Reduced-order models use a reduced space to approximate the parameterized PDE, where the reduced space is of a significantly smaller dimension than that of the discrete PDE. Solving an approximation of the problem on the …
Page 1 of 6