"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:b1024bc5-46ad-450e-a3d3-090a166a67a7","http://resolver.tudelft.nl/uuid:b1024bc5-46ad-450e-a3d3-090a166a67a7","Fast Iterative Solution of the Time-Harmonic Elastic Wave Equation at Multiple Frequencies","Baumann, M.M. (TU Delft Numerical Analysis)","Vuik, C. (promotor); van Gijzen, M.B. (copromotor); Delft University of Technology (degree granting institution)","2018","Seismic Full-Waveform Inversion is an imaging technique to better understand the earth's subsurface. Therefore, the reflection intensity of sound waves is measured in a field experiment and is matched with the results from a computer simulation in a least-squares sense. From a computational point-of-view, but also from an economic view point, the efficient numerical solution of the elastic wave equation on current hardware is the main bottleneck of the computations, especially when a large three-dimensional computational domain is considered. In our research, we focused on an alternative problem formulation in frequency-domain. The mathematical challenge then becomes to efficiently solve the time-harmonic elastic wave equation at multiple frequencies. The resulting sequence of shifted linear systems is solved with a new framework of Krylov subspace methods derived for this specific problem formulation. Our numerical analysis gives insight in the theoretical convergence behavior of the new algorithm.","Krylov subspace methods; Preconditioning; Shifted linear systems; Time-harmonic elastic wave equation; MSSS matrix computations; Spectral analysis","en","doctoral thesis","","978-94-6295-827-2","","","","","","","","","","","",""