A new paper is added to the collection of reproducible documents:
Seismic data decomposition into spectral components using regularized nonstationary autoregression

Seismic data can be decomposed into nonstationary spectral components with smoothly variable frequencies and smoothly variable amplitudes. To estimate local frequencies, I use a nonstationary version of Prony’s spectral analysis method defined with the help of regularized nonstationary autoregression (RNAR). To estimate local amplitudes of different components, I fit their sum to the data using regularized nonstationary regression (RNR). Shaping regularization ensures stability of the estimation process and provides controls on smoothness of the estimated parameters. Potential applications of the proposed technique include noise attenuation, seismic data compression, and seismic data regularization.

A new paper is added to the collection of reproducible documents:
Shortest path ray tracing on parallel GPU devices

A new parallel algorithm for shortest path ray tracing on graphics processing units was implemented. This algorithm avoids the enforcing of mutual exclusion during path calculation that is found in other parallel graph algorithms and that degrades their performance. Tests with velocity models composed of millions of vertices with a high conectivity degree show that this parallel algorithm outperforms the sequential implementation.

This is a contribution from Jorge Monsegny, UP Consultorias, and William Agudelo, ICP-Ecopetrol.