784 research outputs found

    Coordinating heterogeneous IoT devices by means of the centralized vision of the SDN controller

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    The IoT (Internet of Things) has become a reality during recent years. The desire of having everything connected to the Internet results in clearly identified benefits that will impact on socio economic development. However, the exponential growth in the number of IoT devices and their heterogeneity open new challenges that must be carefully studied. Coordination among devices to adapt them to their users' context usually requires high volumes of data to be exchanged with the cloud. In order to reduce unnecessary communications and network overhead, this paper proposes a novel network architecture based on the Software-Defined Networking paradigm that allows IoT devices coordinate and adapt them within the scope of a particular context.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Expresión plástica tridimensional: acercamiento a la realidad en educación infantil

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    En teoría, la realidad que nos rodea supone un mundo tridimensional, ese mundo tangible que todos intentamos entender y transmitir a los más pequeños. Este aporte se puede lograr de una forma aislada o de una forma consciente estableciendo redes que nos ayuden a entender no sólo nuestro cuerpo y entorno cercano, sino a aproximarnos hacia la asimilación de la belleza de las formas naturales y artificiales que nos rodea. Sin embargo, en la práctica, estos logros se frustran porque no todos los docentes priorizan el concepto de volumen. Una de las virtudes de enseñar a partir de lo tridimensional es que enseñamos a partir del verdadero acercamiento a la realidad

    Ant colony optimized planning for unmanned surface marine vehicles

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    This paper presents some results achieved from a preliminary study on the use of the Ant Colony Algorithm to plan feasible optimal or suboptimal trajectories for an autonomous ship manoeuvring. The scenario, for this preliminary work, comprises only open sea manoeuvres. The goal involves obtaining the least time consuming ship trajectory between to points, departing from the start point with arbitrary initial speed and attitude values and arriving to the end point with predefined speed and attitude values. The specific dynamic of the ship imposes typical restrictions to its manoeuvrability. In the present case, the non-holonomicity, the rate speed/turn radius, and the imposed forward-only propulsion of the ship make up the main restrictions to the ship movement. For long distances, the problem could be tackled as a classical navigation problem, in which, for the most part of the ship trajectory, techniques such inertial navigation should be enough. The problem arises at short distances when it becomes a manoeuvring problem. In this case to obtain a optimal, --in some cases just a feasible--, trajectory could be a difficult problem.Peer Reviewe

    Obesity as a risk factor in COVID-19: Possible mechanisms and implications

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    Varios artículos recientes sugieren que la obesidad es un factor de riesgo para una enfermedad más grave por coronavirus. En este artículo se resume la evidencia científica disponible sobre el papel de la obesidad en COVID-19, con especial atención en las personas más jóvenes y los mecanismos biológicos propuestos para explicar tanto el mayor riesgo observado como la posible mayor contagiosidad de esta población. Se consideran varias implicaciones de la pandemia sobre las personas con obesidad, en relación con las posibles dificultades en el manejo de los pacientes ingresados, las implicaciones del confinamiento sobre el control y tratamiento de la obesidad, y el estigma que sufren estas personas por su condición, y que puede verse aumentado si se confirma la relación de la obesidad con COVID-19. Comprender el papel de la obesidad en COVID-19 debería ser una prioridad de salud pública, dada la alta prevalencia de esta condición en nuestro país.Recent reports suggest that obesity is a risk factor for more severe coronavirus disease. This article summarizes the available scientific evidence on the role of obesity in COVID-19. We focus on implications for younger patients and the proposed biological mechanisms that could explain both the higher risk observed and the possible higher contagiousness of people with obesity. We consider implications of the pandemic for people with obesity in relation to: difficulties in managing hospitalized patients, implications of confinement for the control and treatment of obesity, and the stigma people with obesity suffer, that could increase should the relationship between obesity and COVID-19 be confirmed. Understanding the role of obesity in COVID-19 should be a public health priority, given the high prevalence of this condition in our country

    Density and Spatial Distribution of Nests of Ectatomma ruidum and Pheidole fallax (Hymenoptera: Formicidae), as Response to the Recovery of Coal Mine Areas

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    In this study, the spatial pattern of two ant species of different feeding habits, Ectatomma ruidum and Pheidole fallax (Hymenoptera: Formicidae) was assessed in rehabilitated areas of “Cerrejón” coal mine (Colombia). We tested whether there is a relationship between spatial distribution pattern, age rehabilitation and temporal changes. Three sites with different ages of rehabilitation (1, 9 and 20 years) and a secondary forest were sampled during dry and rainy seasons. Within four plots (6 x 40m) per site, we located, counted and estimated the minimum distance among nests. Our results indicated that the number of active nests varied according to sites and sampling season, E. ruidum had the highest density at both seasons, 166 nests ha-1 (forest) and 1333 nests ha-1 (9-y site). The nest density for P. fallax ranged between 125 and 625 nests ha-1 in the forest and the 20-y site, respectively, and at 1-year site ants were absent. Our results indicated that the nest distribution strongly depended on the scale of observation. A uniform distribution pattern was also found, mainly at the local scale (plot level), while an aggregated and random distribution was found at the site level. We conclude that ant density responded mostly to seasonal changes (dry versus wet season)

    Subjective quality assessment in stereoscopic video based on analyzing parallax and disparity

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    Disparity may cause visual discomfort. Pairs of video sequences with different levels of parallax, both negative and positive, were presented together to the observers. The observers evaluated the cases in which visual discomfort occurred after visualizing the transition on each pair

    Proposal for Characterization of 3DTV Video Sequences Describing Parallax Information

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    Recommendations such as P.910 suggests parameters TI (temporal information) and SI (spatial information) for characterizing video sequences for quality assessment. In this paper, we suggest two additional parameter based on disparity called SPI (spatial parallax information) and TPI (temporal parallax information) to characterize 3DTV video sequences for this purpose

    Insertion of impairments in test video sequences for quality assessment based on psychovisual characteristics

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    Assessing video quality is a complex task. While most pixel-based metrics do not present enough correlation between objective and subjective results, algorithms need to correspond to human perception when analyzing quality in a video sequence. For analyzing the perceived quality derived from concrete video artifacts in determined region of interest we present a novel methodology for generating test sequences which allow the analysis of impact of each individual distortion. Through results obtained after subjective assessment it is possible to create psychovisual models based on weighting pixels belonging to different regions of interest distributed by color, position, motion or content. Interesting results are obtained in subjective assessment which demonstrates the necessity of new metrics adapted to human visual system

    Gas phase selective hydrogenation of furfural to furfuryl alcohol and 2-methylfuran over Cu-CeO2 coprecipitated catalysts

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    Furfural is an important chemical derived from lignocellulosic biomass, in particular from C5 sugars like xylose, and it is considered as a platform molecule of great potential for the synthesis of a broad spectrum of chemicals. In this sense, furfuryl alcohol and 2-methylfuran are two important chemicals which can be produced through furfural hydrogenation, either in liquid or vapor phase, although the latter is preferred because it can be carried out at atmospheric pressure. Industrially, a copper chromite catalyst is used, although this catalyst can become very toxic due to the presence of chromium. Therefore, much attention is being paid to the development of chromium-free catalysts, more sustainable and environmentally friendly, as those based on Cu or Ni which are active and selective towards the formation of furfuryl alcohol and 2-methylfuran. Furfuryl alcohol is mainly used for the production of thermostatic resins, intermediate in the manufacture of lysine, vitamin C and dispersing agents. Meanwhile, 2-methyl furan is used in the synthesis of pesticides, or in the pharmaceutical and fragrance industries. The aim of this work is the synthesis of a series of copper based catalysts, which have been synthesized by coprecipitation of copper and cerium(IV) and subsequent thermal programmed reduction. This method allows increasing the dispersion of Cu particles, while the use of a support like CeO2 can modify the electronic density of the active phase, which can influence the catalytic activity and resistance to deactivation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Economy and Competitiveness Ministry (Project CTQ2012-38204-C03-02), Junta de Andalucía (Project: RNM-1565) and FEDER funds of the European Unio

    RAPID AND SIMPLE DETERMINATION OF IBUPROFEN AND CAFFEINE IN FIXED-DOSE COMBINATION FORMULATIONS: APPLICATION TO DISSOLUTION STUDIES

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    Objective: To develop a UV-derivative spectrophotometric method with zero-crossing determinations for the simultaneous quantification of ibuprofen (IBU) and caffeine (CAF) in fixed-dose combination formulations (soft gelatin capsules). The proposed method was validated, and it was applied to determine the in vitro dissolution performance of IBU and CAF from a commercial formulation. Methods: The method is based on the use of the second-derivatives of the zero-order spectra and measurement at zero-crossing wavelengths. Linearity, accuracy, precision, stability, and influence of the filter were evaluated. Dissolution profiles of IBU and CAF were obtained with the USP Apparatus 2 at 100 rpm and 900 ml of 0.1 M phosphate buffer pH 7.4 as dissolution medium. Dissolution samples were treated with the proposed UV-derivative method and results were compared with data previously published. Results: The zero-crossing points for the determination of IBU and CAF were found at 235.6 nm and 218.8 nm, respectively. The method was linear in the range of 7.5-15 µg/ml for IBU and 5-25 µg/ml for CAF (R2>0.999, *P<0.05). The precision and accuracy of the method were within acceptable criteria (CV<0.99% and recovery 97.97% for IBU and CV<1.76% and recovery 99.05% for CAF). Fiberglass filters were the best option to filter samples and stability of all drugs was adequate when solutions were stored at 25 °C during 24 h. Dissolution of IBU and CAF at 60 min was 99-100% with dissolution profiles of sigmoidal S-shape. Weibull function and Logistic were the best-fit models that describe the in vitro dissolution performance of both drugs. Conclusion: The proposed UV-derivative method allows the simultaneous determination of IBU and CAF in fixed-dose combination formulations. The method generates reliable information that can be compared with published data. The proposed UV-derivative method is rapid and simple and can be easily adopted for routine analysis of IBU and CAF
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