Tomography in the post-migrated domain is quickly becoming the standard approach for obtaining velocities in complex areas. The standard flow to update the velocity through tomography in the post-migrated domain begins by migrating the data using some initial velocity model. This migration method can be Kirchhoff (Etgen, 1990), downward continuation methods (Clapp, 2001b; Mosher et al., 2001), ...

Accurate permeability estimation has always been a concern in determining flow units, assigning appropriate capillary pressure andrelative permeability curves to reservoir rock types, geological modeling, and dynamic simulation.Acoustic method can be used as analternative and effective tool for permeability determination. In this study, a four-step approach is proposed for permeability estimati...

Following earlier studies which showed that a sparse coding principle may explain the receptive field properties of complex cells in primary visual cortex, it has been concluded that the same properties may be equally derived from a slowness principle. In contrast to this claim, we here show that slowness and sparsity drive the representations towards substantially different receptive field pro...

In recent years, Spatial Markov Models have gained popularity in simulating solute transport heterogeneous formations. They describe the transition times of particles between equidistant observation planes by statistical distributions, assuming correlation transit individual subsequent steps. By this, approach naturally captures preasymptotic dispersion. this study, we analyze bivariate log-nor...

Using the technique developed by Newman and Okal [J. Geophys. Res. 103 (1998) 26885], a dataset of digital records from 84 earthquakes is analyzed to investigate their source slowness in the quest for a possible regional signal in three subduction zones which experienced recent tsunami earthquakes (Nicaragua, 1992; Java, 1994; Peru, 1996). The dataset is augmented by analog seismograms from his...

A new 2-D traveltime tomography algorithm has been developed for use with long offset seismic streamer data. The forward problem is solved using initial value ray tracing in Delaunay triangulated grids. The traveltimes are calculated analytically. The linearised joint interface and velocity inversion is regularised via a geostatistical smoothing regularisation based on the formulation of a data...

Loss of the ability to move is the most characteristic and fundamental motor deficit in Parkinson’s disease. Parkinsonian patients exhibit akinesia (inability to initiate movement), hypokinesia (reduced movement), and bradykinesia (slowness of the movement itself). (All these phenomena will be subsumed under the title akinesia.) Rigid muscles may contribute to akinesia, but they are not the cau...