We introduce a novel technique for seismic wave extrapolation in time. The technique involves cascading a Fourier Transform operator and a finite difference operator to form a chain operator: Fourier Finite Differences (FFD). We derive the FFD operator from a pseudo-analytical solution of the acoustic wave equation. 2-D synthetic examples demonstrate that the FFD operator can have high accuracy...

In chapter 10 migration is described in terms of double focussing. In chapter 11 focussing in emission is used to synthesize common focus point gathers (CFP gathers). By comparing aCFPgather with its related focussing operator velocity errors can be detected and the focussing operator can be corrected (Berkhout and Rietveld (1994), Rietveld and Berkhout (1994) , Berkhout (1992), Rietveld and Th...

The method of time domain electromagnetic (TDEM) migration is used for fast imaging of subsurface geoelectrical structures. The computation of the migration field is based on downward extrapolation of the observed field in reverse time. In this paper we examine an effective method of EM migration based on the operator of an integral transformation in the spatial-temporal domain. The migration c...

Metamodel evolution requires model migration. To correctly migrate models, evolution needs to be made explicit. Manually describing evolution is error-prone and redundant. Metamodel matching offers a solution by automatically detecting evolution, but is only capable of detecting primitive evolution steps. In practice, primitive evolution steps are jointly applied to form a complex evolution ste...

Biogeography is the study of distribution of biological species, over space and time, among random habitats. Recently developed Biogeography-Based Optimization (BBO) is a technique, where solutions of the problem under consideration are named as habitats; similar to chromosome in Genetic Algorithms (GAs) and particles in Particle Swarm Optimization (PSO). Feature sharing among various habitats,...

The paper focuses on third generation wireless technologies and on alternative technologies for wireless local area networks. The authors present the evolutionary migration path from second to third generation systems. Technological, economic and behavioral factors related to decision-making towards the migration are proposed. As an example, the paper studies the case of the national incumbent ...

A cloud-based data stream management system (DSMS) handles fast data by utilizing the massively parallel processing capabilities of the underlying platform. An important property of such a DSMS is elasticity, meaning that nodes can be dynamically added to or removed from an application to match the latter’s workload, which may fluctuate in an unpredictable manner. For an application involving s...

Both migration deconvolution (MD) and least squares migration (LSM) are capable of improving the resolution and suppress acquisition footprints in migrated images. In this paper, we investigate the relative performance of these two technologies in enhancing migration image quality, suppressing artifacts and computational efficiency. Both MD and LSM were tested on SEG/EAGE overthrust models. The...