Sparse Representation based on Dictionary Learning

Speaker: 
Ricardo Soares

Affiliation: 
NORCE Energy

Seminar Date: 
16. October 2019 - 11:15 - 11:45

This work presents the use of the Dictionary Learning method for a sparse representation of 4D seismic data. We consider a trade-off between the number of nonzero coefficients retained in the sparse data representation, the computational cost, and how well we can capture the main features of the original 4D seismic signal. K-SVD is an iterative algorithm used in Dictionary Learning that alternates between the calculation of the sparse representation vector and dictionary update. The algorithm starts with the definition of an initial dictionary (Discrete Cosine Transform, for instance).

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Physical and biogeochemical variability off Baja California (Mexico): insights from numerical NPZD ocean models

Speaker: 
David Rivas

Affiliation: 
CICESE

Seminar Date: 
30. August 2019 - 13:15 - 14:00

Physical-biogeochemical Nitrate-Phytoplankton-Zooplankton-Detritus (NPZD)
numerical models are used to study the variability of nutrients and
phytoplankton biomass in coastal waters off Baja California Peninsula, a
region of high socioeconomic importance located in the southern California
Current System. The focus of these analyses has been the effects of
interannual climatic anomalies. For example, the year 2006 was anomalously
warm and with low chlorophyll (Chl) levels, associated with warm phases of
El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation

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Lagrangian ocean analysis to study the physical mechanisms driving the processes occurring in the Greater Agulhas Current System

Speaker: 
Michael Hart-Davis

Seminar Date: 
13. August 2019 - 11:15 - 11:45

Lagrangian ocean analysis is a powerful way to study ocean processes from in-situ observations and numerical model simulations. As numerical modelling capabilities develop and physical mechanisms of the ocean are better understood, the importance of particle trajectory modelling continues to increase. Therefore, developing cross-disciplinary particle trajectory model applications for the Greater Agulhas System is highly relevant due to its potential contribution to scientific studies and operational applications.

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Explore dynamical information with Pseudo-orbit Data Assimilation

Speaker: 
HAILIANG DU

Affiliation: 
Durham University

Seminar Date: 
13. June 2019 - 11:00 - 12:00

Physical processes such as the weather are usually modeled using nonlinear dynamical systems. Traditional statistical approaches are found to be difficult to draw dynamical information from the nonlinear dynamics. This talk is focusing on exploring dynamical information with Pseduo-orbit data assimilation to address various problems encountered in analyzing and modeling nonlinear dynamical systems. The talk will start with solving an “impossible” challenge pointed out by Berliner (1991) when applying the Bayesian paradigm to state estimation in chaotic systems.

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Korea Satellite Remote Sensing of the Arctic

Speaker: 
Hyun-Cheol Kim

Affiliation: 
Korea Polar Research Institute (KOPRI)

Seminar Date: 
28. March 2019 - 15:00 - 15:30

Dr. Hyun-Cheol Kim is the director of Unit of Arctic Sea-Ice Prediction, Korea Polar Research Institute (KOPRI).
As a remote sensing scientist, he will give us a talk regarding the research activities of KOPRI.
After the seminar, NERSC and KOPRI will sign a MoU.