in this article, dynamics of the cerebrospinal fluid (csf) was studied, using computational fluid dynamics. using mri images of two special cases, a 2-dimensional model of the ventricular system was made. csf velocity and pressure distribution in ventricular system have high importance since the flow pattern of this liquid has an important effect on intracranial pressure, i.e., icp, which has a...

During the early 1980s, the phenomenon of acoustic-to-seismic coupling was used to detect buried objects or mines. In these early measurements, large 2 Hz geophones measured the low frequency (50-300 Hz) normal component of the soil particle velocity over buried targets. Several different, naturally-occurring ground types were studied in these measurements, including grass-covered ground; bare,...

The interest in dynamic behavior of railway bridges has increased in recent years with the introduction of high speed trains. Higher speeds of the trains have resulted in larger and more complicated loads than earlier, producing significant dynamic effects. The dynamic aspects are of special interest and have often shown to be the governing factor in the structural design. Dynamic analysis of r...

There is a general consensus that 3D reference models can be used to isolate effects of wave propagation and thus help in improving characterization of seismic sources. Advances in computation and numerical method have made it possible to capture increasingly broadband, full wave generation and propagation in 3D earth models. The main objectives of this project are to construct hierarchical, mu...

[1] The most common form of seismic exploration remains a nearly linear survey with data acquisition lines including the source and receivers. The interpretation of amplitude and waveform information for such linear acquisition requires consideration of 3D seismic wavefields. In many scenarios the structure is approximately 2D, but still modeling is needed for point sources. In recent years 2.5...

in exploration seismology, migration refers to a multi-channel processing step that attempts to spatially re-position events and improve focusing. before migration, seismic data is usually displayed with traces plotted at the surface location of the receivers and with a vertical time axis. this means that dipping reflections are systematically mispositioned in the lateral coordinate and the ver...

We review the resolution currently available with seismic tomography, in particular the ability of seismic waves to image mantle plumes, and discuss frequently asked questions about artifacts, interpretation and possible systematic errors. These aspects are discussed in more detail for two case histories offering different problems in the tomographic interpretation: Iceland and Hawaii. Regional...

S U M M A R Y Converted phase (CP) elastic seismic signals are comparable in amplitude to the primary signals recorded at large offsets and have the potential to be used in seismic imaging and velocity analysis. We present an approach for CP elastic wave equation velocity analysis that does not use source information and is applicable to surface-seismic, microseismic, teleseismic and vertical s...