Beatriz Otero

Low dispersive modeling of Rayleigh waves on partly staggered grids

In elastic media, finite-difference (FD) implementations of free-surface (FS) boundary conditions on partly staggered grid (PSG) use the highly dispersive vacuum formulation (VPSG). The FS boundary is embedded into a “vacuum” grid layer (null Lame’s constants and negligible density values) where the discretized equations of motion allow computing surface displacements. We place a new set of compound (stress-displacement) nodes along a planar FS and use unilateral mimetic FD discretization of the zero-traction conditions for displacement computation (MPSG). At interior nodes, MPSG reduces to standard VPSG methods and applies fourth-order centered FD along cell diagonals for staggered differentiation combined with nodal second-order FD in time. We perform a dispersion analysis of these methods on a Lamb’s problem and estimate dispersion curves from the phase difference of windowed numerical Rayleigh pulses at two FS receivers. For a given grid sampling criterion (e.g., six or ten nodes per reference S wavelength λS), MPSG dispersion errors are only a quarter of the VPSG method. We also quantify root-mean-square (RMS) misfits of numerical time series relative to analytical waveforms. MPSG RMS misfits barely exceed 10 % when nine nodes sample the minimum S wavelength λMINS

A domain decomposition strategy for GRID environments

\lambda _{\text {MIN}}^{\mathrm {S}}

Compact finite difference modeling of 2-D acoustic wave propagation

in transit (along distances ∼

A new mimetic scheme for the acoustic wave equation

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Self-organized server farms for energy savings

145λMINS

Data distribution strategies for domain decomposition applications in grid environments

\lambda _{\text {MIN}}^{\mathrm {S}}

Performance analysis of domain decomposition applications using unbalanced strategies in grid environments

). In same tests, VPSG RMS misfits exceed 70 %. We additionally compare MPSG to a consistently fourth-order mimetic method designed on a standard staggered grid. The latter equates the former’s dispersion errors on grids twice denser and shows higher RMS precision only on grids with six or less nodes per λMINS

A performance analysis of a mimetic finite difference scheme for acoustic wave propagation on GPU platforms

\lambda _{\text {MIN}}^{\mathrm {S}}

Compact Finite Difference Schemes for the Acoustic Wave Equation

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La presencia de la mujer en las carreras tecnológicas

In this paper, we evaluate the performance of domain decomposition applications with message-passing in GRID environments. We compare two domain decomposition strategies, the balanced and the unbalanced one. The balanced strategy is the normal strategy used in homogenous computing environment. This strategy present some problems related with the heterogeneous communications in a grid environment. We propose an unbalanced domain decomposition strategy in order to overlap the slow communications with computation. The influence of the communication patterns on execution times is analysed. DIMEMAS simulator is used to predict the performance of distributed applications in GRID environments.