Three-dimensional flow patterns at a river difluence on the alluvial system of the Paraná River, Argentina

Water Qualit

Distance metric learning : a two-phase approach

Distance metric learning has been successfully incorporated in many machine learning applications. The main challenge arises from the positive semidefiniteness constraint on the Mahalanobis matrix, which results in a high computational cost. In this paper, we develop a novel approach to reduce this computational burden. We first map each training example into a new space by an orthonormal transformation. Then, in the transformed space, we simply learn a diagonal matrix. This two-phase approach is thus much easier and less costly than learning a full Mahalanobis matrix in one phase as is commonly done

El amparo de garantías constitucionales. Análisis y presupuestos para su modificación.

El ser humano; desde tiempos pretéritos se ha propuesto vivir dentro de un Estado Constitucional de Derecho. Históricamente, las Constituciones plasman los Derechos Fundamentales más aceptados por la Sociedad. Asimismo, se establecen las figuras jurídicas de garantías de los derechos directamente instituidos en la Constitución. La figura de “Amparo de Garantías Constitucionales” es una figura jurídica esencial de protección de los Derechos Fundamentales. Es sabido que las Sociedades cambian en el transcurso del tiempo, por lo que el Derecho Constitucional debe adaptarse a las aspiraciones y las necesidades de los seres humanos. En Panamá, apremia la necesidad de modificar la Constitución en lo referente a la figura de “Amparo”. Claro está que la Ciencia del Derecho no pertenece a las Ciencias Matemáticas, por lo que la protección de los Derechos Fundamentales de las personas no depende solamente de un cambio constitucional efectivo. Además, se necesita un desarrollo legal eficaz y acciones Políticas encaminadas a garantizar la dignidad plena del pueblo. Esta investigación propone la plasmación constitucional de la figura de Acción de Protección de Derechos Fundamentales, basada en la Teoría de los Derechos Fundamentales que plantea una concepción tridimensional del Derecho; es decir, un Derecho a Defensa, un Derecho a Protección y un Derecho a Procedimiento. Es posible que los Derechos Fundamentales colisionen dentro de un caso concreto, por lo que aceptamos la regla de ponderación para resolver el problema. Lo anterior posibilita una adecuada protección de los Derechos Fundamentales frente a posibles vulneraciones por cualquier persona y la salvaguarda de la Constitución Política de la República de Panamá

Biosensors in Rehabilitation and Assistance Robotics

Robotic developments in the field of rehabilitation and assistance have seen a significant increase in the last few years [...

Human Pose Detection for Robotic-Assisted and Rehabilitation Environments

Assistance and rehabilitation robotic platforms must have precise sensory systems for human–robot interaction. Therefore, human pose estimation is a current topic of research, especially for the safety of human–robot collaboration and the evaluation of human biomarkers. Within this field of research, the evaluation of the low-cost marker-less human pose estimators of OpenPose and Detectron 2 has received much attention for their diversity of applications, such as surveillance, sports, videogames, and assessment in human motor rehabilitation. This work aimed to evaluate and compare the angles in the elbow and shoulder joints estimated by OpenPose and Detectron 2 during four typical upper-limb rehabilitation exercises: elbow side flexion, elbow flexion, shoulder extension, and shoulder abduction. A setup of two Kinect 2 RGBD cameras was used to obtain the ground truth of the joint and skeleton estimations during the different exercises. Finally, we provided a numerical comparison (RMSE and MAE) among the angle measurements obtained with OpenPose, Detectron 2, and the ground truth. The results showed how OpenPose outperforms Detectron 2 in these types of applications.Óscar G. Hernández holds a grant from the Spanish Fundación Carolina, the University of Alicante, and the National Autonomous University of Honduras

One-dimensional moir\'e superlattices and flat bands in collapsed chiral carbon nanotubes

We demonstrate that one-dimensional moir\'e patterns, analogous to those found in twisted bilayer graphene, can arise in collapsed chiral carbon nanotubes. Resorting to a combination of approaches, namely, molecular dynamics to obtain the relaxed geometries and tight-binding calculations validated against ab initio modeling, we find that magic angle physics occur in collapsed carbon nanotubes. Velocity reduction, flat bands and localization in AA regions with diminishing moir\'e angle are revealed, showing a magic angle close to 1$^{\rm o}$. From the spatial extension of the AA regions and the width of the flat bands, we estimate that many-body interactions in these systems are stronger than in twisted bilayer graphene. Chiral collapsed carbon nanotubes stand out as promising candidates to explore many-body effects and superconductivity in low dimensions, emerging as the one-dimensional analogues of twisted bilayer graphene

Object Recognition in Noisy RGB-D Data

The object recognition task on 3D scenes is a growing research field that faces some problems relative to the use of 3D point clouds. In this work, we focus on dealing with noisy clouds through the use of the Growing Neural Gas (GNG) network filtering algorithm. Another challenge is the selection of the right keypoints detection method, that allows to identify a model into a scene cloud. The GNG method is able to represent the input data with a desired resolution while preserving the topology of the input space. Experiments show how the introduction of the GNG method yields better recognitions results than others filtering algorithms when noise is present.The object recognition task on 3D scenes is a growing research field that faces some problems relative to the use of 3D point clouds. In this work, we focus on dealing with noisy clouds through the use of the Growing Neural Gas (GNG) network filtering algorithm. Another challenge is the selection of the right keypoints detection method, that allows to identify a model into a scene cloud. The GNG method is able to represent the input data with a desired resolution while preserving the topology of the input space. Experiments show how the introduction of the GNG method yields better recognitions results than others filtering algorithms when noise is present

Universality of moir\'e physics in collapsed chiral carbon nanotubes

We report the existence of moir\'e patterns and magic angle physics in all families of chiral collapsed carbon nanotubes. A detailed study of the electronic structure of all types of chiral nanotubes, previously collapsed via molecular dynamics, has been performed. We find that each family possesses a unique geometry and moir\'e disposition, as well as a characteristic number of flat bands. Remarkably, all kinds of nanotubes behave the same with respect to magic angle tuning, showing a monotonic behavior that gives rise to magic angles in full agreement with those of twisted bilayer graphene. Therefore, magic angle behavior is universally found in chiral collapsed nanotubes with a small chiral angle, giving rise to moir\'e patterns. Our approach comprises first-principles and semi-empirical calculations of the band structure, density of states and spatial distribution of the localized states signaled by flat bands

Teinture dans des bains de reutilitsation directe: des microfibres de polyester avec des colorants dispersés

Las presiones medioambientales sobre la industria textil y el consumo de agua y energía de dicho sector, llevan a la adopción de medidas que influyen directamente sobre los procesos industriales de tintura. Disminuir el impacto medioambiental optimizando procesos para conseguir mejorar el nivel de agotamiento y/o reutilizar los baños finales, con o sin tratamiento intermedio, son algunas de las medidas que se vienen aplicando. En este trabajo se estudiará el caso de reutilizaciones directas de baños de tintura con CI Azul Disperso 56 y microfibras de poliéster, con el objeto de evaluar su comportamiento en cinéticas no isotérmicas en el caso de 25 reutilizaciones a partir del baño original. A partir de los resultados obtenidos puede observarse una tendencia del % de agotamiento con el número de reutilizaciones. Disminuye hasta la 5º reutilización, manteniéndose aproximadamente constante des de la 6ª hasta la número 25.Environmental pressures on textile industry and the consumption of water and energy in the above mentioned sector, lead to the adoption of measures that directly influence to the industrial processes. In order to reduce the environmental impact, optimizing process to improve exhaustion level and/or the reuse of final baths, with or without intermediate treatment, are some of the measures that have been applied. In this work, the case of direct reuses of residual baths with Disperse Blue 56 and poliéster microfibres will be studied. The main objective is to evaluate their behaviour in non-isothermal kinetics in the specific case of 25 reuses from the same original bath. From the results obtained a tendence in the exhaustion percentage can be observed respect the number of reuses. It diminishes until the 5th, maintaining its values from the 6th until the 25th reuse.Les pressions environnementales sur l'industrie textile et la consommation d'eau et l'énergie du dit secteur, portent à l'adoption de mesures qui influent directement sur les processus industriels de teinture. Diminuer l'impact environnemental en optimisant des processus pour réussir à améliorer le niveau d'épuisement et/ou réutiliser les bains finaux, avec ou sans un traitement intermédiaire, sont certains des mesures qui sont appliquées. À ce travail on étudiera le cas de réutilisations directes de bains de teinture avec CI Bleu Dispersé 56 et des microfibres de polyester, afin d'évaluer sa conduite dans cinétiques non isothermes dans le cas de 25 réutilisations à partir du bain original. À partir des résultats obtenus on peut observer une tendance du % d'épuisement avec le nombre de réutilisations. On diminue jusqu'à la 5º réutilisation, en se maintenant à peu près constant depuis la 6 ª jusqu'au nombre 25