Abstract: Methods, apparatus, and systems are provided for on-line seminars over a network. A client receives sets of program code that perform operations requested by a presenter. A stream is transmitted from a server to the client for the presentation. The server detects the operations requested by the presenter and pushes an event that indicates the requested operation into the stream. The client receives the event, selects a set of program codes based on information in the pushed event, and executes the selected set of program code in synchronization with the at least one stream.

Abstract: Disclosed is separation of the compressional and shear components of the wavefield measured in 3-component vertical seismic profiling. The separation involves working in the zx plane defined by the borehole axis (z) and the surface seismic source space therefrom along the x-axis, and in successive and overlapping windows each defined by (i) a depth interval centered at the depth level currently being processed and including several depth levels above and below and (ii) a time interval sufficiently long to allow the relevant seismic wavefield to be measured by the geophones. The total wavefield measurements in a window are rotated to give the wavefield along the borehole axis (z) and that perpendicular to it in the zx plane of interest.