3,305 research outputs found

    Detección de M señales gaussianas utilizando el desarrollo modificado de un proceso estocástico

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    Utilizando el desarrollo modificado de un proceso estocástico se propone una nueva metodología, alternativa a la basada en el desarrollo de Karhunen-Loeve, para el problema de detección de M señales Gaussianas en ruido Gaussiano blanco. Las soluciones proporcionadas no presentan el problema del cálculo de los autovalores y autofunciones asociados a la función de covarianza involucrada y son fácilmente implementables desde el punto de vista práctico

    Applying A Methodology For Educating Students With Special Needs: A Case Study

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    The introduction of innovative educational technologies opens up new ways of interacting with students. We propose to exploit this potential to help in the education of children with special needs. We analyze the state of the art of tools supporting the teaching process, focusing on the omissions of existing research. We propose a new framework to help throughout the whole teaching process and describe its application to Proyecto Aprender (Learn Project), an educational resource targeting children with learning difficulties. Finally, we outline some conclusions and current/future research lines

    Identificar cobertura vegetal de suelo clasificando pixeles en imágenes hiperepectrales con SVM (maquinas de soporte vectorial)

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    Se realizó un experimento para clasificar 4 clases de cobertura vegetal de suelo usando imágenes hiperespectrales, con 63 bandas. Se trabajó con un pixel representado por vector de 63 características (uno por banda). Se probaron nueve filtros y el análisis sin filtro. Para la clasificación se usó una máquina de soporte vectorial (SVM), con un kernel perceptor multicapa (MLP). Se obtienen precisiones aceptables, mejorando muchas encontradas en la literatura [1] [2]. Con este trabajo se demuestra que es mejor usar imágenes hiperespectrales que las comúnmente usadas. Los resultados sugieren que es necesario emplear otras técnicas o pre-proceso para mejorar las clasificaciones en este tipo de imágenes

    Nonlinear model predictive control for thermal management in plug-in hybrid electric vehicles

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    © 2016 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.A nonlinear model predictive control (NMPC) for the thermal management (TM) of Plug-in Hybrid Electric Vehicles (PHEVs) is presented. TM in PHEVs is crucial to ensure good components performance and durability in all possible climate scenarios. A drawback of accurate TM solutions is the higher electrical consumption due to the increasing number of low voltage (LV) actuators used in the cooling circuits. Hence, more complex control strategies are needed for minimizing components thermal stress and at the same time electrical consumption. In this context, NMPC arises as a powerful method for achieving multiple objectives in Multiple input- Multiple output systems. This paper proposes an NMPC for the TM of the High Voltage (HV) battery and the power electronics (PE) cooling circuit in a PHEV. It distinguishes itself from the previously NMPC reported methods in the automotive sector by the complexity of its controlled plant which is highly nonlinear and controlled by numerous variables. The implemented model of the plant, which is based on experimental data and multi- domain physical equations, has been validated using six different driving cycles logged in a real vehicle, obtaining a maximum error, in comparison with the real temperatures, of 2C. For one of the six cycles, an NMPC software-in-the loop (SIL) is presented, where the models inside the controller and for the controlled plant are the same. This simulation is compared to the finite-state machine-based strategy performed in the real vehicle. The results show that NMPC keeps the battery at healthier temperatures and in addition reduces the cooling electrical consumption by more than 5%. In terms of the objective function, an accumulated and weighted sum of the two goals, this improvement amounts 30%. Finally, the online SIL presented in this paper, suggests that the used optimizer is fast enough for a future implementation in the vehicle.Accepted versio

    Influence of the hydrodynamic size and ζ potential of manganese ferrite nanozymes as peroxidase‒mimicking catalysts at ph 4 in different buffers

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    Peroxidase-mimicking activity of manganese ferrite nanoparticles was studied, based on the oxidation of TMB (3,3’,5,5’-tetramethylbenzidine) by H2O2 at pH 4 using acetate and citrate buffers. The aim of this study was to examine this reaction not only by enzymology (Michaelis-Menten kinetics model) but also by surface science methods of heterogeneous catalysis. Nanoparticles were characterized by different techniques to determine their phase composition, surface area, surface composition, surface charge, pH at the point of zero charge, magnetization, mean size, and morphology. Results show that the nanozymes are coated with buffer anions that form a shell around them. In addition, the hydrodynamic size and ζ potential of the nanoparticles under reaction conditions play an important role in the proposed Fenton-type oxidation mechanism. A greater amount of Mn ions than Fe ions leaches from the nanozymes during TMB oxidation, likely because Fe is better protected than Mn by the buffer coating the outer surface of the nanoparticles. This shortcoming must be addressed when applying these nanomaterials.Operative Program, and Junta de Andalucía FEDER 2014-2020 (Projects FEDER-UJA-138062

    Acute p-synephrine ingestion increases whole-body fat oxidation during 1-h of cycling at Fatmax.

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    Purpose p-Synephrine, the principal alkaloid of bitter orange (Citrus aurantium), is widely used in dietary supplements for weight loss due to its purported effect of increasing fat oxidation. However, there is a paucity of scientific information about its effectiveness in enhancing fat oxidation during exercise. The aim of this investigation was to determine the effect of an acute dose of p-synephrine on substrate oxidation during prolonged and constant intensity exercise. Methods In a double-blind and randomized experiment, 14 healthy subjects performed two acute experimental trials after ingesting either p-synephrine (3 mg kg−1) or a placebo (cellulose). Energy expenditure and fat oxidation rates were continuously measured by indirect calorimetry during 1 h of continuous cycling at Fatmax, the intensity that induces maximal fat oxidation rate. Results In comparison to the placebo, energy expenditure during 1 h of cycling remained unchanged with p-synephrine (698 ± 129 vs. 686 ± 123 kcal, P = 0.08). However, p-synephrine increased whole-body fat oxidation (33.6 ± 10.4 vs. 37.3 ± 9.8 g, P < 0.01) while also reducing carbohydrate oxidation (99.5 ± 30.4 vs. 85.0 ± 28.4 g, P < 0.01). However, the magnitude of the shift on substrate oxidation induced by p-synephrine was small. Conclusion Acute ingestion of p-synephrine augments fat oxidation during prolonged and constant-intensity exercise.pre-print193 K

    Effect of caffeine on muscle oxygen saturation during short‑term all‑out exercise: a double‑blind randomized crossover study.

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    Purpose The ergogenic effect of oral caffeine administration on short-term all-out exercise performance is well established. However, the potential mechanisms associated with caffeine’s ergogenicity in this type of exercise are poorly understood. The aim of this study was to investigate whether caffeine intake modifies muscle oxygen saturation during the 15-s Wingate Anaerobic Test. Methods Fifteen moderately trained individuals (body mass = 67.4 ± 12.3 kg; height 171.3 ± 6.9 cm; age 31 ± 6 years) took part in two identical experimental trials after the ingestion of (a) 3 mg/kg of caffeine or (b) 3 mg/kg of cellulose (placebo). After 60 min for substances absorption, participants performed a 15-s Wingate test on a cycle ergometer against a load representing 7.5% of participant’s body mass. Muscle oxygen saturation was continuously measured during exercise with near-infrared spectroscopy and blood lactate concentration was measured 1 min after exercise. Results In comparison to the placebo, the oral administration of caffeine increased peak power by 2.9 ± 4.5% (from 9.65 ± 1.38 to. 9.92 ± 1.40 W/kg, P = 0.038; effect size (ES), 95% confidence intervals = 0.28, 0.05–0.51), mean power by 3.5 ± 6.2% (from 8.30 ± 1.08 to 8.57 ± 1.12 W/kg, P = 0.044; ES = 0.36, 0.01–0.71) and blood lactate concentration by 20.9 ± 24.7% (from 12.4 ± 2.6 to 14.8 ± 4.0 mmol/L, P = 0.005; ES = 0.59, 0.16–1.02). However, caffeine did not modify the curve of muscle oxygen desaturation during exercise (lowest value was 23.1 ± 14.1 and 23.4 ± 14.1%, P = 0.940). Conclusion Caffeine’s ergogenic effect during short-term all-out exercise seems to be associated with an increased glycolytic metabolism with no influence of enhanced muscle oxygen saturation.post-print839 K

    The European Union can afford greater ambition in the conservation of its threatened plants

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    The importance of Natura 2000 network for the conservation of natural habitats, wild flora and fauna at European level is undeniable. However, it may not have reached its full potential since the loss of biodiversity continues to increase year on year. Further on, a third of the plant species listed in the Habitats Directive to guide the declaration of European Union Natura 2000 network of protected areas is not threatened and there is broad agreement on the need to review and update the species list. Here, the effectiveness of Natura 2000 in the conservation of Spanish bryophytes and vascular plants included in the Habitats Directive Annex II is analysed and compared with the one offered to the species included in the Spanish Red Lists. Results show a remarkable coverage of Natura 2000 over the distribution areas of threatened species, thus providing an umbrella effect on these taxa. It confirms that the number of plant species in the Habitats Directive could be significantly extended without altering the current configuration of the network. This would allow the incorporation of scientific advances produced since the Habitats Directive was approved almost 30 years ago, and will contribute to the goals of the new European Biodiversity Strategy for 2030, such as to consider impacts caused by alien species, land use or climate changesThe Spanish Ministry of Science, Innovation and Universities supported J.C.M.S. through the Bioregions 2.0 project (CGL2017-86926-P

    Temporal evolution of acid mine drainage (AMD) leachates from the abandoned tharsis mine (Iberian Pyrite Belt, Spain)

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    Acid mine drainage (AMD) due to the mining of sulfide deposits is one of the most important causes of water pollution worldwide. Remediation measures, especially in historical abandoned mines, require a deep knowledge of the geochemical characteristics of AMD effluents and metal fluxes, considering their high spatial and temporal evolution, and the existence of point and diffuse sources with a different response to rainfall events. This study investigates the temporal variations and hydrogeochemical processes affecting the composition of main AMD sources from the Tharsis mines (SW Spain), one of most important historical metal mining districts in the world. To address this, a fortnightly-monthly sampling was performed during two years in the main AMD sources and streams within the mine site covering different hydrological conditions. A seasonal pattern was observed linked to hydrological variations; higher pollutant concentrations were observed during the dry season (maximum values of 4,6 g/L of Al, 11,8 g/L of Fe, and 67 g/L of sulfate) and lower ones were observed during the rainy periods. Stream samples exhibited a negative correlation between electrical conductivity (EC) and flow, while positive values were observed in AMD sources, where groundwater fluxes were predominant. High flow also seems to be the main driver of Pb fluxes from AMD sources, as the concentration of Pb in waters increased notably during these events. The precipitation of secondary Fe minerals may limit the mobility of As and V, being retained in the proximity of mine sites. The concentration of Zn in waters seems to be controlled by the original grade in the metal deposit from which the waste is generated, together with the age of these wastes. The pollutant load delivered by the Tharsis mines to the surrounding water courses is very high; e.g., mean of 733 ton/yr of Al or 2757 ton/yr of Fe, deteriorating the streams and reservoirs downstream.This work was supported by the Spanish Ministry of Economic and Competitiveness through the projects CGL2016-78783-C2-1-R (SCYRE) and by H2020 European Institute of Innovation and Technology (EIT RawMaterials) through the projects Modular recovery process services for hydrometallurgy and water treatment (MORECOVERY). C.R Canovas thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference RYC2019- 027949-I. F. Macias was funded by the R&D FEDER Andalucía 2014–2020 call through the project RENOVAME (FEDER; UHU-1255729). Funding for open access charge: Universidad de Huelva/CBU

    Stimulus Expectancy and Stimulus Response of Caffeine on 4-Km Running Performance: a Randomized, Double-Blind, Placebo-Controlled and Crossover Study

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    International Journal of Exercise Science 15(2): 645-654, 2022. The placebo effect of caffeine has been poorly investigated in endurance exercise. Therefore, the aim of this study was to analyze the placebo effect of caffeine on 4 km running performance in amateur runners. Twenty-two healthy and recreational male runners (25.5 ± 8.4 yrs; 75.0 ± 7.1 kg; 173.7 ± 6.3 cm) underwent a deceptive experimental design consisting of three different sessions: a) control (CON) in which participants did not ingest any substance; b) placebo (PLA) in which participants ingested a capsule filled with maltodextrin but they were informed that they would receive caffeine; c) caffeine (CAF) in which participants were informed that they would receive caffeine and actually received caffeine. After 60 min for substances absorption, participants performed a 4-km test and they completed the distance as fast as possible. The time employed to cover the distance was lower in PLA (17.4 ± 1.5 min) and CAF (17.4 ± 1.4 min) than CON sessions (18.6 ± 2.8 min; P\u3c0.05). There were no differences in the 4-km times between PLA and CAF (P\u3e0.05) and no differences were reported between treatments for RPE (P\u3e0.05). In conclusion, there was a placebo effect of caffeine on a 4-km maximal running trial which entailed that believing to have ingested caffeine improved performance to a similar extent than actually receiving caffeine. Therefore, the expectancy induced by caffeine may be one of the mechanisms behinds the ergogenic effect of this stimulant on endurance exercise
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