Regionalization and connectivity in the Gulf of Cádiz and Alborán Sea implication for marine spatial planning and coastal management

This work proposes a regionalization of marine waters south of the Iberian Peninsula based on empirical orthogonal functions and GIS analysis. The regions identified are consistent and correspond to hydrological mesoscale and macroscale structures well characterized from physical and biological viewpoints. Although it is difficult to determine the boundaries of a fluid continuously moving, the procedure used recognizes the most frequent patterns and can be used to reference geographically the most likely position of the limit among the regions. Once established the regions, the connectivity among them is addressed by means of geostrophic currents derived from altimetry data. The main geostrophic circulation pattern depict an elevate connectivity in the area that might facilitate the conservation and recovering of species, but also imply a higher vulnerability to negative externalities and highlight the need of models, marine spatial planning, and coastal management approaches that includes the pelagic ecosystem and connectivity of the seas. Furthermore, the results confirm that the cooperation between public authorities at different levels (local, regional, state) as well as among riparian countries is essential for marine spatial planning and prevention of potential risk derived from upcoming marine activities in the framework of the 2020 agenda and Blue Growth strategy.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Stress vs sputtering effects in the propagation of surface ripples produced by ion-beam sputtering

The proceeding at: 19th International Conference on Ion Beam Modification of Materials (IBMM 2014). Took place at 2014, September, 14-19, in Bruges (Belgium). The event Web Site in https://iks32.fys.kuleuven.be/indico/event/16/Under low energy ion irradiation, periodic features (ripples) can develop on the surfaces of semiconductor materials, with typical sizes in the nanometric range. Recently, a theory of pattern formation has been able to account for the variability with the ion/target combination of the critical angle value separating conditions on ion incidence that induce the presence or the absence of ripples. Such a theory is based in the accumulation of stress in the damaged irradiated layer and its relaxation via surface-confined viscous flow. Here we explore the role of stress, and its competition with purely erosive mechanisms, to deter-mine the sign of the velocity with which the ripple pattern moves across the target plane. Based on this theory, we discuss different situations and make specific testable predictions for the change of sign in that velocity.Our work has been funded through MINECO (Spain) grants FIS2012-38866-C05-01, FIS2012-32349, and FIS2013-47949-C2-2. A.M.-B. acknowledges support from MINECO, through FPI scholarship BES-2010-036179.Publicad

An adaptable approach to learn realistic legged locomotion without examples

© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Learning controllers that reproduce legged locomotion in nature has been a long-time goal in robotics and computer graphics. While yielding promising results, recent approaches are not yet flexible enough to be applicable to legged systems of different morphologies. This is partly because they often rely on precise motion capture references or elaborate learning environments that ensure the naturality of the emergent locomotion gaits but prevent generalization. This work proposes a generic approach for ensuring realism in locomotion by guiding the learning process with the spring-loaded inverted pendulum model as a reference. Leveraging on the exploration capacities of Reinforcement Learning (RL), we learn a control policy that fills in the information gap between the template model and full-body dynamics required to maintain stable and periodic locomotion. The proposed approach can be applied to robots of different sizes and morphologies and adapted to any RL technique and control architecture. We present experimental results showing that even in a model-free setup and with a simple reactive control architecture, the learned policies can generate realistic and energy-efficient locomotion gaits for a bipedal and a quadrupedal robot. And most importantly, this is achieved without using motion capture, strong constraints in the dynamics or kinematics of the robot, nor prescribing limb coordination. We provide supplemental videos for qualitative analysis of the naturality of the learned gaits.Peer ReviewedPostprint (author's final draft

Evaluación de las propiedades físicas y factores de conversión de café variedad Castillo y Colombia (Coffea arabica L.) durante el proceso de beneficio y trilla, a diferentes alturas sobre el nivel del mar en fincas cafeteras el municipio de Colón, departamento de Nariño.

El presente estudio se realizó en fincas cafeteras del Municipio de Colón, Departamento de Nariño, el objetivo fue determinarlas propiedades físicas y factores de conversión del café variedad Castillo y Colombia (Coffea arabica L.), en el proceso de beneficio húmedo y trilla, a diferente altitud m.s.n.m., se utilizó un diseño en bloques en tres niveles de alturas diferentes de 1350 m.s.n.m. a 1600 m.s.n.m., de 1600 m.s.n.m a 1800 m.s.n.m, de 1800 m.s.n.m a 2200 (dos fincas por rango de altura y variedad), con el fin de determinar el efecto de la altura y la variedad, sobre las variables de respuesta: peso, diámetros (polar y ecuatorial), densidad aparente, relaciones de conversión, porcentaje de merma y rendimiento en trilla. Se tomó una muestra de café cereza sin seleccionar; para cada muestra se tomaron sub muestras que se procesaron mediante el sistema de beneficio húmedo y secado solar en parabólico. Se utilizó el análisis de varianza para determinar si existen diferencias estadísticamente significativas entre las diferentes muestras. Respecto a la densidad aparente se obtuvo mayores resultados para café variedad Castillo, 712 kg/m3 para café cereza, 873,9 kg/m3 para el café en baba, 766,6 kg/m3 para el café lavado, 484,6 kg/m3 para el café pergamino seco y 814 kg/m3 para el café almendra, se determinó diferencia estadísticamente significativa respecto al porcentaje de merma, en promedio para el café variedad Castillo de solo 17,46%, a diferencia de la variedad Colombia de 18,156%. Se encontró diferencia estadísticamente significativa entre el peso, diámetro polar y diámetro ecuatorial con respecto a la altura, a medida que aumento la altura disminuye el peso y los diámetros del grano, siendo estos mayores para el café variedad Castillo en todos los estados del café. Al final se obtuvo unos mejores resultados para la variedad Castillo y se determinó que la altura tiene una influencia predominante sobre las propiedades físicas y factores de conversión del café.The objective of this study was to determine the physical properties and conversion factors of the coffee variety Castillo and Colombia (Coffea arabica L.), in the process of humid and threshing benefit, at the coffee farms of the Municipality of Colón, Department of Nariño. Different altitude msnm, a block design was used in three levels of different heights of 1350 msnm At 1600 masl, from 1600 masl to 1800 masl, from 1800 masl to 2200 (two estates per height range and variety), in order to determine the effect of height and variety, on the response variables: weight, diameters (Polar and equatorial), apparent density, conversion ratios, shrinkage percentage and threshing performance. A sample of cherry coffee was taken without selecting; For each sample, sub samples were taken and processed by means of the wet profit and solar parabolic drying system. The analysis of variance was used to determine if there are statistically significant differences between the different samples. Regarding the apparent density, the results were higher for Castillo variety, 712 kg / m3 for cherry coffee, 873.9 kg / m3 for coffee in drool, 766.6 kg / m3 for washed coffee, 484.6 kg / M3 for dry parchment coffee and 814 kg / m3 for almond coffee, a statistically significant difference was determined with respect to the percentage of reduction, in average for the Castillo variety coffee of only 17.46%, unlike the Colombia variety of 18.156%. There was a statistically significant difference between the weight, the polar diameter and the equatorial diameter with respect to the height. As the height increased, the weight and diameter of the grain were reduced, being higher for the Castillo variety coffee in all coffee states. In the end, better results were obtained for the Castillo variety and it was determined that the height has a predominant influence on the physical properties and coffee conversion factors

Morphological symmetries in robot learning

This work studies the impact of morphological symmetries in learning applications in robotics. Morphological symmetries are a predominant feature in both biological and robotic systems, arising from the presence of planes/axis of symmetry in the system's morphology. This results in harmonious duplication and distribution of body parts (e.g., humans' sagittal/left-right symmetry). Morphological symmetries become a significant learning prior as they extend to symmetries in the system's dynamics, optimal control policies, and in all proprioceptive and exteroceptive measurements, related to the system's dynamics evolution \cite{ordonez2023discrete}. Exploiting these symmetries in learning applications offers several advantageous outcomes, such as the use of data augmentation to mitigate the cost and challenges of data collection, or the use of equivariant/invariant function approximation models (e.g., neural networks) to improve sample efficiency and generalization, while reducing the number of trainable parameters. Lastly, we provide a video presentation and an open access repository reproducing our experiments and allowing for rapid prototyping in robot learning applications exploiting morphological symmetries.This work is supported by the Spanish government with the project MoHuCo PID2020-120049RB-I00 and the ERA-Net Chistera project IPALM PCI2019-103386.Peer ReviewedPostprint (published version

Model-free reinforcement learning with a non-linear reconstructor for closed-loop adaptive optics control with a pyramid wavefront sensor

We present a model-free reinforcement learning (RL) predictive model with a supervised learning non-linear reconstructor for adaptive optics (AO) control with a pyramid wavefront sensor (P-WFS). First, we analyse the additional problems of training an RL control method with a P-WFS compared to the Shack-Hartmann WFS. From those observations, we propose our solution: a combination of model-free RL for prediction with a non-linear reconstructor based on neural networks with a U-net architecture. We test the proposed method in simulation of closed-loop AO for an 8m telescope equipped with a 32x32 P-WFS and observe that both the predictive and non-linear reconstruction add additional benefits over an optimised integrator.This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 873120.Peer ReviewedPostprint (author's final draft

Surface CuO, Bi2O3, and CeO2 species supported in TiO2-anatase: Study of Interface Effects in Toluene Photodegradation Quantum Efficiency

The enhancement of active triggered by surface deposition of Cu, Bi, and Ce containing oxidic species onto a high surface area anatase is analyzed through the calculation of the quantum efficiency for toluene photodegradation under UV and Sunlight-type illumination. To this end, series of Cu, Bi, and Ce containing oxides supported on anatase were synthesized having a growing content of the Cu, Bi, and Ce surface species and characterized with X-ray diffraction and photoelectron, UV-visible, and photoluminescence spectroscopies as well as transmission electron microscopy. Utilizing the surface concentration of Cu, Bi, and Ce species as a tool, we analyzed the influence of the system physicochemical properties affecting quantum efficiency in anatase-based materials. First, employing small surface concentrations of the Cu, Bi, and Ce species deposited onto (the unperturbed) anatase, we provided evidence that all steps of the photocatalytic event, including light absorption, charge recombination, as well as surface interaction with the pollutant and chemical output as to activity and selectivity have significance in the quantitative assessment of the enhancement of the efficiency parameter. Second, we analyzed samples rendering maximum quantum efficiency within all these series of materials. The study indicates that maximum enhancement over anatase displays a magnitude strongly dependent on the efficiency level of calculation and would thus require the use of the most accurate one, and that it occurs through a balance between optoelectronic and chemical properties of the composite materials. The (Cu, Bi, Ce) oxide-anatase interface plays a major role modulating the optoelectronic properties of the solids and thus the efficiency observableFinancial support by MINECO (ENE2013-46624-C4-1-R) is gratefully acknowledge