In time-reversal acoustics, waves recorded at the boundary of a strongly scattering medium are sent back into the medium to focus at the original source position. This requires that the medium can be accessed from all sides. We discuss a focusing method for media that can be accessed from one side only. We show how complex focusing functions, emitted from the top surface into the medium, cause ...

Two kinds of pre-white dwarf stars can be probed through asteroseismology: planetary nebula nuclei (PNNs) and sdB (EHB) stars. To exploit the observed pulsations requires models that incorporate state-ofthe-art input physics and realistic evolutionary histories. Pulsation analysis of extensive grids of such models provide self-consistent theoretical pulsation periods for comparison with observe...

Earthquake data composes an ever increasing collection of earth science information for postprocessing analysis. Earth scientists, local or national administration officers and so forth, are working with these data collections for scientific or planning purposes. In this article, we discuss the architecture of a so-called seismic data management and mining system (SDMMS) for quick and easy data...

The widespread application of the hybrid empirical method (HEM) has made it a viable approach for developing ground motion prediction equations in regions where there are few strong motion recordings but there are ample weak motion data from small-magnitude earthquakes. The HEM uses empirical estimates of ground motion in one region (the host region) to provide estimates of ground motion in ano...