SUMMARY Traditional earthquake location relying on first arrival picking is challenging for microseismic events with low signal-to-noise ratio. Over the past years, alternative procedures have been explored based idea of migrating energy an back into its source position by stacking along theoretical traveltime curves. To avoid destructive interference signals opposite polarity, it common to tra...

This paper describes a simple method to evaluate an acoustic altered zone around the borehole using an array of sonic waveforms. The method is based on a semblance velocity analysis and a nonlinear travel time window is introduced. On the assumption that a velocity gradient of the altered zone may be linear, the nonlinear travel time window is calculated as a function of averaged velocity and a...

The chief problems that software engineering will face over at least the next two decades are increasing application complexity, and the need for autonomy and serious application robustness. In other words, how do we actually get to declare success when trying to build applications one or two orders of magnitude more complex than today’s applications? And, having declared success when building,...

We present a high-resolution procedure to reconstruct common-midpoint (CMP) gathers. First, we describe the forward and inverse transformations between offset and velocity space. Then, we formulate an underdetermined linear inverse problem in which the target is the artifacts-free, aperture-compensated velocity gather. We show that a sparse inversion leads to a solution that resembles the infin...

The architects of phase I radiochemotherapy development programs impose a semblance of structured radiation "intensity" and adverse event predictability upon radiation-anticancer agent interactions whose natural complexity and improper mixing would otherwise lead to dire health consequences. It is incumbent upon radiation oncology investigators to pledge radiation quality and safety to the part...

The work flow of migration velocity analysis (MVA) is widely used in seismic exploration of hydrocarbon reservoirs to refine velocity models and obtain precise information about subsurface structures. Therefore the velocity uncertainty introduced in the MVA process directly affects assessments of structural uncertainty and reservoir volumes. In order to quantify the velocity uncertainty in MVA ...

The lack of human interaction in automatic reflection tomography leads to a larger percentage of “bad” data points. The number of data points associated with events with spurious moveouts (such as multiples and converted waves) can be minimized by intelligently controlling the semblance scanning range. The effect of the bad data points can be limited by replacing the standard L2 norm solution w...