The relationship between nonword repetition ability and vocabulary size and vocabulary learning has been a topic of intense research interest and investigation over the last two decades, following the demonstration that nonword repetition accuracy is predictive of vocabulary size (Gathercole & Baddeley, 1989). However, the nature of this relationship is not well understood. One prominent accoun...

The objective of seismic imaging is to obtain an image of the subsurface reflectors, which is very important for estimating whether a reservoir is beneficial for oil/gas exploration or not. It can also provide the relative changes or absolute values of three elastic parameters: compressional wave velocity Vp, shear wave velocity Vs , and density ρ. Two ways can achieve the objectives. In approa...

In this paper I compared imaging conditions of three different prestack migrations in terms of angle-dependent reflectivity recovery. The imaging conditions compared are shot profile migration with conventional imaging condition, de Brduin’s imaging condition, and planewave synthesis imaging. The conventional imaging condition can be applied to any reflector geometry and to arbitrary velocity, ...

s). “Quantifying errors in fracture orientations estimated from PS converted wave” by Michelena (SEG 1995 Expanded Abstracts). “Stratigraphic inversion of poststack PS converted waves data,” by Valenciano and Michelena (SEG 2000 Expanded Abstracts). “Tomography + prestack depth migration of PS converted waves” by D’Agosto et al. (SEG 1998 Expanded Abstracts). “Pand S-wave separation ats). “Pand...

We present a review of common-azimuth prestack depth migration theory and propose a new extension to the original method. In common-azimuth migration theory, source and receiver raypaths are constrained to lie on the same plane at each depth level. By using data with a broader range of cross-line offsets, we increase the number of raypaths examined and consider more information. Consequently, o...

Migration in the angle domain creates seismic images for different reflection angles. We present a method for computing angle-domain common-image gathers from seismic images obtained by depth migration using wavefield continuation. Our method operates on prestack migrated images and produces the output as a function of the reflection angle, not as a function of offset ray parameter as in other ...

It is common in shallow seismic studies for the compressional-wave velocity in unconsolidated sediments to increase by a factor of four or more at the transition from dry or partial water saturation to full saturation. Under these conditions, conventional NMO velocity analysis fails and leads to large depth and layer thickness estimates if the Dix equation is assumed valid. Prestack depth migra...

Joint inversion of different geophysical datasets is an effective way to eliminate non-uniqueness in geophysical inversion problems. In this paper, we focus on a case study of joint inversion of seismic traveltime and gravity observations. The results are encouraging and we can have confidence that, comparing traveltime tomography alone, joint inversion of seismic traveltime and gravity data im...

CFP technology (Berkhout, 1996a,b) addresses these limitations in a novel way. By breaking the model determination process into two simpler, more easily solved problems, those of operator estimation and macro model estimation, the final solution will typically be more accurate. Moreover, by providing rapid local convergence to the correct travel-time operators, migration analysis can be automat...