A5077500993- Atmospheric Ozone and Climate
- Atomic and Subatomic Physics Research
- Calibration and Measurement Techniques
- Atmospheric and Environmental Gas Dynamics
- Water Quality Monitoring Technologies
- COVID-19 diagnosis using AI
- Radiomics and Machine Learning in Medical Imaging
- Seismic Waves and Analysis
- Seismic Imaging and Inversion Techniques
- Methane Hydrates and Related Phenomena
- Blind Source Separation Techniques
- Image and Signal Denoising Methods
- Power Quality and Harmonics
- Water Quality Monitoring and Analysis
- Advanced Electrical Measurement Techniques
- Speech and Audio Processing
- Spectroscopy and Chemometric Analyses
- Seismology and Earthquake Studies
- Underwater Vehicles and Communication Systems
- Underwater Acoustics Research
- Coastal and Marine Management
- Advanced Optical Sensing Technologies
- Electromagnetic Simulation and Numerical Methods
- Magnetic Properties and Applications
- Hydraulic Fracturing and Reservoir Analysis
Institut Català de Ciències del Clima
2022
Institut de Ciències del Mar
2014-2022
Consejo Superior de Investigaciones Científicas
2006-2016
Marine Technology Unit
2005-2012
IFP Énergies nouvelles
2012
Geociencias Barcelona
2012
National Research Council
2005-2009
Orange (France)
1993-1995
Institut de Recherche en Informatique et Systèmes Aléatoires
1995
The S-transform is becoming popular for time-frequency analysis and data-adaptive filtering thanks to its simplicity. While this transform works well in the continuous domain, discrete version may fail achieve accurate results. This paper compares contrasts with better known wavelet transform, defines a relation between both. connection allows understanding of S-transform, makes it possible employ reconstruction formula as new inverse propose several methods solve some main limitations such...
The aim of this paper is to present a study on the potential and limits -transform its inverses. S-transform an extension short-time Fourier transform with characteristics wavelet transform. It mostly used for time-frequency analyses. Two different inverse S-transforms have been presented in literature. We explain why most recent one approximation but very good one. level calculated paper. then discuss relative merits both A careful enables us show that, although inverses are nearly exact...
Marine processes are observed with sensors from both the ground and space over large spatio-temporal scales. Citizen-based contributions can fill observational gaps increase environmental stewardship amongst public. For this purpose, tools methods for citizen science need to (1) complement existing datasets; (2) be affordable, while appealing different user developer groups. In article, developed in 7th Framework Programme of European Union (EU FP 7) funded project Citclops (citizens’...
The poster presents the Ocean Cities Network (OC-NET) program and its main event, Month, an annual celebration launched in 2021 that takes place various cities across OC-NET network around world engages thousands of people each year. This event promotes connection respect between coastal ocean. encourages residents these to recognize crucial role ocean plays their lives, fostering a regenerative relationship ranges from local activities global collaboration networks. Month serves as platform...
The TT-transform stands for time-time transform and has been derived as an inverse Fourier of the time-frequency <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> -transform. Up to date, only diagonal used signal characterization. We show here alternative simplified derivation which enables a better understanding this transform. In particular, we demonstrate that elements represent simple frequency filtered version original and, thus, little...
A critical parameter to assess the environmental status of water bodies is transparency water, as it strongly affected by different quality related components (such presence phytoplankton, organic matter and sediment concentrations). One diffuse attenuation coefficient. However, number subsurface irradiance measurements obtained with conventional instrumentation relatively low, due instrument costs logistic requirements provide regular autonomous observations. In recent years, citizen...
This paper presents a modification of the adaptive cross approximation (ACA) algorithm for accelerated solution Method Moments linear system electrically large radiation and scattering problems. As with ACA, subblocks impedance matrix that represent interaction between well separated subdomains are substituted by "compressed" approximations allowing reduced storage iterative solution. The modified approximates original products sparse matrices, constructed aid ACA sub-sampling basis...
One of the most critical decisions in design a local-slant-stack transform (LSST) is selection its aperture, or more precisely, appropriate number traces and their weighting coefficients for each slant stack. The challenge to achieve good compromise between slowness spatial resolution. Conventionally, window size chosen intuitive manner by visual inspection some limited tests. We analyzed LSST establish rigorous criteria optimum resolution transformed domain given data set. For this purpose,...
We address the problem of separation convolutive mixtures in case where non-Gaussian source signals are not necessarily filtered versions i.i.d. sequences. In this context, we study behavior schemes based on maximization a fourth-order cumulant contrast function, which known to be consistent if first non-iterative approach sketched recently by Comon and Moreau (see IEEE SP Letters, vol.3, no.7, p.209-21, 1996) Pesquet vol.4, no.6, p.182-83, 1996), explain why it seems questionable non case....
We consider the problem of blind separation causal minimum phase convolutive mixtures two sources. study in detail so-called decorrelation approach. It consists finding a filter which, driven by observations, produces decorrelated outputs. is well established that this approach allows one to separate sources if mixing non-static FIR filter. show result no longer true IIR case. establish there exists infinitely many filters producing outputs and provide parameterisation these filters. This...
Shelf waters near large cities, such as Barcelona, are affected not only by meteorological episodes but also anthropogenic influence. Scientists usually use data from on-site coastal platforms to analyze and understand these complex water ecosystems because remote sensing satellites have low spatiotemporal resolution do provide reliable so close the coast. However, with conventional oceanographic instrumentation expensive install maintain. This study presents scientific adaptation initial...
In this paper, we address the problem of separation convolutive mixtures in case where non-Gaussian source signals are not necessarily filtered versions i.i.d. sequences. context, show that contrast functions, used linear process case, still allow to separate sources by a deflation approach. Some particular properties higher order cumulants based functions also given.
The low cost moored system KdUINO allows to measure parameters related water transparency, specifically the diffuse attenuation coefficient parameter. In this contribution, its measurements are compared with other high precision scientific commercial instrument in order estimate sensor measurement error.
The S-transform provides a framework for data-adaptive filters which take advantage of time-frequency localized spectra. These basically consist in data transformation to the domain, weighting spectra, and back transformation. We illustrate that inverse manipulated spectra not necessarily transforms signals as expected from imposed weighting. time localization is directly translated spurious noise can be generated. discuss this problem suggest new may come helpful many applications more localization.