Diverging fluctuations of the Lyapunov exponents

D. P. acknowledges support by MINECO (Spain) under a Ramón y Cajal fellowship. We acknowledge support by MINECO (Spain) under Project No. FIS2014-59462-P.Peer reviewedPublisher PD

Spatial Adaptive Speckle Filtering Driven by Temporal Polarimetric Statistics and Its Application to PSI

Persistent scatterer (PS) interferometry (PSI) techniques are designed to measure ground deformations using satellite synthetic aperture radar (SAR) data. They rely on the identification of pixels not severely affected by spatial or temporal decorrelation, which, in general, correspond to pointlike PSs commonly found in urban areas. However, in urban areas, we can find not only PSs but also distributed scatterers (DSs) whose phase information may be exploited for PSI applications. Estimation of DS parameters requires speckle filtering to be applied to the complex SAR data, but conventional speckle filtering approaches tend to mask PS information due to spatial averaging. In the context of single-polarization PSI, adaptive speckle filtering strategies based on the exploitation of amplitude temporal statistics have been proposed, which seek to avoid spatial filtering on nonhomogeneous areas. Given the growing interest on polarimetric PSI techniques, i.e., those using polarimetric diversity to increase performance over conventional single-polarization PSI, in this paper, we propose an adaptive spatial filter driven by polarimetric temporal statistics, rather than single-polarization amplitudes. The proposed approach is able to filter DS while preserving PS information. In addition, a new methodology for the joint processing of PS and DS in the context of PSI is introduced. The technique has been tested for two different urban data sets: 41 dual-polarization TerraSAR-X images of Murcia (Spain) and 31 full-polarization Radarsat-2 images of Barcelona (Spain). Results show an important improvement in terms of number of pixels with valid deformation information, hence denser area coverage.This work was supported in part by the Spanish Ministerio de Economía y Competitividad and in part by the European Union FEDER funds under Project TEC2011-28201-C02-02

Scaling Vision-based End-to-End Driving with Multi-View Attention Learning

On end-to-end driving, human driving demonstrations are used to train perception-based driving models by imitation learning. This process is supervised on vehicle signals (e.g., steering angle, acceleration) but does not require extra costly supervision (human labeling of sensor data). As a representative of such vision-based end-to-end driving models, CILRS is commonly used as a baseline to compare with new driving models. So far, some latest models achieve better performance than CILRS by using expensive sensor suites and/or by using large amounts of human-labeled data for training. Given the difference in performance, one may think that it is not worth pursuing vision-based pure end-to-end driving. However, we argue that this approach still has great value and potential considering cost and maintenance. In this paper, we present CIL++, which improves on CILRS by both processing higher-resolution images using a human-inspired HFOV as an inductive bias and incorporating a proper attention mechanism. CIL++ achieves competitive performance compared to models which are more costly to develop. We propose to replace CILRS with CIL++ as a strong vision-based pure end-to-end driving baseline supervised by only vehicle signals and trained by conditional imitation learning.Comment: This paper has been accepted to the 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2023

Soil-Structure Interaction for Integrated Design of Weakened and Damped Structures

Previous research has shown the effectiveness of the integrated design of weakening and damping techniques (WeD) for the seismic retrofitting of structures. Indeed, WeD techniques are able to reduce inter-story drifts and total accelerations, the two major performance measures to evaluate the seismic behavior of structures. Past research has been applied to fixed-based structures considering relatively stiff soil conditions. It has been suspected, though, that using such techniques in soft soil sites while considering soil structure interaction, may diminish some of the advantages observed in past research. This paper examines the effect of site conditions and soil-structure interaction on the seismic performance of Weakening and Damping techniques. An established rheological soil-shallow foundation-structure model with equivalent linear soil behavior and nonlinear behavior of the superstructure has been used. A large number of models incorporating wide range of soil, foundation and structural parameters were generated using robust Monte-Carlo simulation. The various structural models, along with the various site conditions, have been used for the comparative study. The design methodologies previously developed by the authors have been applied to each model considering different site conditions leading to the optimal weakening and damping. The results of the comparative study are used to quantify the effects of site conditions and foundation °exibility on the performance of the retrofitted structures

Polarimetric Approaches for Persistent Scatterers Interferometry

In previous works, a general framework to exploit polarimetric diversity to optimize the results of persistent scatterers interferometry (PSI) was presented, but tested only with dual-pol data. In this paper, the performance of these algorithms is assessed using fully polarimetric data, acquired by the Radarsat-2 satellite over the urban area of Barcelona, Spain. In addition, two new highly efficient polarimetric optimization methods, mean intensity polarimetric optimization and joint diagonalization-based polarimetric optimization, are introduced and evaluated. Given the variety of dual-pol configurations provided by current polarimetric satellites, such as TerraSAR-X and Radarsat-2, and the upcoming launch of Sentinel-1, ALOS-2, and Radarsat Constellation Mission, a study has been also carried out to determine the best performing dual-pol configurations for polarimetric PSI. Subsidence maps of the area of study are computed for single-pol, dual-pol, and full-pol data, which show the increase in pixel density with valid deformation results as more polarimetric information is made available. In particular, for full-pol data we get an increase of up to 2.5 times more pixels for coherence-based PSI techniques (degraded resolution), and over four times more for amplitude-based approaches (full resolution), in comparison with single-pol data. Both higher density and quality of pixels yield better results in terms of coverage and accuracy.This work was supported in part by the Spanish Ministerio de Economía y Competitividad and European Union FEDER funds under Project TEC2011-28201-C02-02

Chronic disease relapses: A cross-sectional study of the associated factors and socioeconomic inequalities during the COVID- 19 pandemic in Peru

Objectives To investigate the prevalence, associated factors and socioeconomic inequalities in chronic disease relapses (CDR) during 2020 in Peru. Methods A secondary analysis was made of the National Household Survey on Living Conditions and Poverty (ENAHO) 2020. Participants older than 18 years who suffered from a chronic disease and with information about the occurrence of a CDR in the last 4 weeks prior to the survey were included. Adjusted prevalence ratios (aPRs) were estimated to determine the associated factors. Socioeconomic inequality in CDR was estimated using concentration curves (CC) and the Erreygers concentration index (ECI). Results Data from 38,662 participants were analyzed; the prevalence of CDR in the last 4 weeks prior to the survey was 16.5% (95% CI: 15.8-17.2). Being female (aPR 1.29; 95% CI: 1.21- 1.37), with regards to being male; being 30-39 (aPR 1.22; 95% CI: 1.05-1.42), 40-49 (aPR 1.29; 95% CI: 1.12-1.48), 50-59 (aPR 1.60; 95% CI: 1.41-1.82), and 60 years or older (aPR 1.80; 95% CI: 1.58-2.04), compared to 18-29; reaching up to primary (aPR 1.18; 95% CI: 1.07-1.31), or secondary education (aPR 1.13; 95% CI: 1.02-1.24), in contrast to tertiary education; presenting some physical, psychological or cognitive limitation (aPR 1.33; 95% CI: 1.21-1.46), with respect to experiencing no limitations; and being affiliated to a health insurance (aPR 1.18; CI 95%: 1.09-1.29), opposed to not having health insurance; were associated with a higher probability of CDR. Residing in the natural region of the coastal area (aPR 0.83; 95% CI: 0.74-0.92) was associated with a lower probability of relapse compared to residing in the jungle area. In people with limitations and residents of the jungle areas, the prevalence of CDR was concentrated in those with higher per capita spending. Conclusions Approximately 1 in 6 Peruvians with chronic diseases had a relapse within the last 4 weeks prior to the survey of 2020 and certain geographic and sociodemographic factors were found to be associated with CDR. It was also found that a higher concentration of CDR was observed in the population with the highest per capita spending with some limitations, as well as in residents of the jungle, implying the need for appropriate policy interventions that address CDR with a special focus on these populations.Revisión por pare

Eigendegradation algorithm applied to visco-plastic weak layers

In geotechnical engineering, very often, the soil behavior varies with time. This is of particular interest in many cases such as embankments in soft clays, shear band progression in slopes or where the speed of the application of the load affects the bearing capacity of the material. In this paper, we study the extension of non-local failures using algorithms such as eigenerosion and eigensoftening, in order to evaluate the failure of weak layers. In particular, the time dependence of the progression of shear bands is analyzed through the integration of a Perzyna-type visco-plastic model with a degradation algorithm within the Optimal Transportation Meshfree (OTM) framework. The validation of the proposed algorithm is carried out through three different practical cases, showing very good agreement in all of them

Effect of five enological practices and of the general phenolic composition on fermentation-related aroma compounds in Mencia young red wines

The effects of five technological procedures and of the contents of total anthocyanins and condensed tan- nins on 19 fermentation-related aroma compounds of young red Mencia wines were studied. Multifactor ANOVA revealed that levels of those volatiles changed significantly over the length of storage in bottles and, to a lesser extent, due to other technological factors considered; total anthocyanins and condensed tannins also changed significantly as a result of the five practices assayed. Five aroma compounds pos- sessed an odour activity value >1 in all wines, and another four in some wines. Linear correlation among volatile compounds and general phenolic composition revealed that total anthocyanins were highly related to 14 different aroma compounds. Multifactor ANOVA, considering the content of total anthocy- anins as a sixth random factor, revealed that this parameter affected significantly the contents of ethyl lactate, ethyl isovalerate, 1-pentanol and ethyl octanoate. Thus, the aroma of young red Mencia wines may be affected by levels of total anthocyanin