We used comprehensive electrophysiological/anatomical digital computer models of atrial excitation and the human torso to study the mechanisms of generation of body surface P-waves in normal sinus rhythm, and in middle and lower sinus rhythm. Simulated atrial surface isochrone maps for normal sinus rhythm support the validity of the atrial excitation model. The results suggest that the presence...

in this paper, the behaviour of buried pipelines under the effect of propagation of seismic waves and faulting is studied seperately. the stability of this type of structure was first studied by using three different methods proposed by newmark-hall, kenndey et al. and wang - yeh under the effect of ground faulting. by parametric study, the effect of soil types, size of pipeline, depth of embed...

Excitation of upper hybrid waves associated with the ionospheric heating experiments is assumed to be essential in explaining some of the features of stimulated electromagnetic emissions (SEE). A direct conversion process is proposed as an excitation mechanism of the upper hybrid waves where the energy of an obliquely propagating electromagnetic pump wave is converted into the electrostatic upp...

To estimate the ground motion in two-dimensional (2D), laterally heterogeneous, anelastic media, a hybrid technique has been developed that combines modal summation and the finite-difference method. In the calculation of the local wave field owing to a seismic event, both for small and large epicentral distances, it is possible to take into account the source, path, and local soil effects. As a...

Wave-equation migration using one-way wavefield extrapolation operators is commonly used in industry to generate images of complex geologic structure from 3D seismic data. By design, most conventional wave-equation approaches restrict propagation to downward continuation, where wavefields are recursively extrapolated to depth on Cartesian meshes. In practice, this approach is limited in high-an...

S U M M A R Y Passive seismic methods using earthquakes can be applied for extracting body waves and obtaining information of subsurface structure. In this study, we retrieve direct and reflected plane waves by applying seismic interferometry to the recorded ground motion from a cluster of regional earthquakes. We apply upgoing/downgoing P/S wavefield decomposition, time windowing, and multidim...