The development and progress of fractures is accompanied by the radiation of acoustic waves due to microcracking. In the transient waveforms of acoustic emissions a huge number of information about fracture processes and the state of the material is inherent. Signal-based analysis of acoustic emissions allows, amongst other studies, for a fracture mechanics based investigation of failure. From ...

In this paper we present a novel technique for micro-seismic localization using a group sparse penalization that is robust to the focal mechanism of the source and requires only a velocity model of the stratigraphy rather than a full Green's function model of the earth's response. In this technique we construct a set of perfect delta detector responses, one for each detector in the array, to a ...

Many image processing problems require the enhancement of coherent ow-like structures. This can be accomplished in a natural way by combining anisotropic diiusion ltering and texture analysis by means of the structure tensor (second-moment matrix). In this paper an extension of these ideas to vector-valued images is presented. A structure tensor for vector-valued images is constructed as the su...