161 research outputs found

    Exploiting visual saliency for assessing the impact of car commercials upon viewers

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    Content based video indexing and retrieval (CBVIR) is a lively area of research which focuses on automating the indexing, retrieval and management of videos. This area has a wide spectrum of promising applications where assessing the impact of audiovisual productions emerges as a particularly interesting and motivating one. In this paper we present a computational model capable to predict the impact (i.e. positive or negative) upon viewers of car advertisements videos by using a set of visual saliency descriptors. Visual saliency provides information about parts of the image perceived as most important, which are instinctively targeted by humans when looking at a picture or watching a video. For this reason we propose to exploit visual information, introducing it as a new feature which reflects high-level semantics objectively, to improve the video impact categorization results. The suggested salience descriptors are inspired by the mechanisms that underlie the attentional abilities of the human visual system and organized into seven distinct families according to different measurements over the identified salient areas in the video frames, namely population, size, location, geometry, orientation, movement and photographic composition. Proposed approach starts by computing saliency maps for all the video frames, where two different visual saliency detection frameworks have been considered and evaluated: the popular graph based visual saliency (GBVS) algorithm, and a state-of-the-art DNN-based approach.This work has been partially supported by the National Grants RTC-2016-5305-7 and TEC2014-53390-P of the Spanish Ministry of Economy and Competitiveness.Publicad

    Study of the Electrical Behavior in Intermediate Band-Si Junctions

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    In this study we analyze the electrical behavior of a junction formed by an ultraheavily Ti implanted Si layer processed by a Pulsed Laser Melting (PLM) and the non implanted Si substrate. This electrical behavior exhibits an electrical decoupling effect in this bilayer that we have associated to an Intermediate Band (IB) formation in the Ti supersaturated Si layer. Time-of-flight secondary ion mass spectrometry (ToFSIMS) measurements show a Ti depth profile with concentrations well above the theoretical limit required to the IB formation. Sheet resistance and Hall mobility measurements in the van der Pauw configuration of these bilayers exhibit a clear dependence with the different measurement currents introduced (1menor queA-1mA). We find that the electrical transport properties measured present an electrical decoupling effect in the bilayer as function of the temperature. The dependence of this effect with the injected current could be explained in terms of an additional current flow in the junction from the substrate to the IB layer and in terms of the voltage dependence in the junction with the measurement current

    Electrical decoupling effect on intermediate band Ti-implanted silicon layers

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    We investigated the electrical transport properties of ultraheavily Ti-implanted silicon layers subsequently pulsed laser melted (PLM). After PLM, the samples exhibit anomalous electrical behaviour in sheet resistance and Hall mobility measurements, which is associated with the formation of an intermediate band (IB) in the implanted layer. An analytical model that assumes IB formation and a current limitation effect between the implanted layer and the substrate was developed to analyse this anomalous behaviour. This model also describes the behaviour of the function V/Delta V and the electrical function F that can be extracted from the electrical measurements in the bilayer. After chemical etching of the implanted layer, the anomalous electrical behaviour observed in sheet resistance and Hall mobility measurements vanishes, recovering the unimplanted Si behaviour, in agreement with the analytical model. The behaviour of V/Delta V and the electrical function F can also be successfully described in terms of the analytical model in the bilayer structure with the implanted layer entirely stripped

    Oxidative Stress, Telomere Shortening, and Apoptosis Associated to Sarcopenia and Frailty in Patients with Multimorbidity

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    The presence of oxidative stress, telomere shortening, and apoptosis in polypathological patients (PP) with sarcopenia and frailty remains unknown. Methods: Multicentric prospective observational study in order to assess oxidative stress markers (catalase, glutathione reductase (GR), total antioxidant capacity to reactive oxygen species (TAC-ROS), and superoxide dismutase (SOD)), absolute telomere length (aTL), and apoptosis (DNA fragmentation) in peripheral blood samples of a hospital-based population of PP. Associations of these biomarkers to sarcopenia, frailty, functional status, and 12-month mortality were analyzed. Results: Of the 444 recruited patients, 97 (21.8%), 278 (62.6%), and 80 (18%) were sarcopenic, frail, or both, respectively. Oxidative stress markers (lower TAC-ROS and higher SOD) were significantly enhanced and aTL significantly shortened in patients with sarcopenia, frailty or both syndromes. No evidence of apoptosis was detected in blood leukocytes of any of the patients. Both oxidative stress markers (GR, p = 0.04) and telomere shortening (p = 0.001) were associated to death risk and to less survival days. Conclusions: Oxidative stress markers and telomere length were enhanced and shortened, respectively, in blood samples of polypathological patients with sarcopenia and/or frailty. Both were associated to decreased survival. They could be useful in the clinical practice to assess vulnerable populations with multimorbidity and of potential interest as therapeutic targets

    Far infrared photoconductivity in a silicon based material: vanadium supersaturated silicon

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    We have analyzed the spectral sub-bandgap photoresponse of silicon (Si) samples implanted with vanadium (V) at different doses and subsequently processed by pulsed-laser melting. Samples with V concentration clearly above the insulator-metal transition limit show an important increase of the photoresponse with respect to a Si reference sample. Their photoresponse extends into the far infrared region and presents a sharp photoconductivity edge that moves towards lower photon energies as the temperature decreases. The increase of the value of the photoresponse is contrary to the classic understanding of recombination centers action and supports the predictions of the insulator-metal transition theory

    El informe de arbitraje según la recomendación de publicación y la productividad de los evaluadores

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    El informe de arbitraje de artículos de investigación es un género en el que se cristaliza una parte del proceso colectivo de construcción del conocimiento. Debido a su carácter confidencial, existen muy pocos trabajos que aborden empíricamente este género. A su vez, esos pocos estudios tienen una serie de limitantes, como la falta de definición de la unidad de análisis y la falta de integración de los datos discursivos con los datos sociales de quienes los producen. En este trabajo, presentamos un modelo que busca superar limitantes. Aplicamos este modelo para describir cómo varía el informe de arbitraje según dos atributos extralingüísticos, la recomendación de publicación (aceptar, condicionar o rechazar) y el número de artículos publicados por los evaluadores. Los resultados muestran que ambos atributos extralingüísticos se asocian a cambios específicos del discurso de este género, siendo la recomendación de publicación más determinante que la productividad de los evaluadores.The referee report of research articles is a discursive genre in which a part of the collective process of building knowledge is crystalized. Given its confidentiality, there is little empirical work on this genre. Among these few contributions, a series of limitations can be identified, such as the lack of definition of the unit of analysis or the lack of integration between discursive and sociometric data. In this article, we present a model that contributes to overcoming these limitations. The model was applied with the purpose of analyzing the variation of referee reports according to two extralinguistic variables, i.e., publication recommendation (accepted, conditioned, rejected) and referee's number of published articles. The results showed that both extralinguistic attributes were associated with specific discourse variations, of which publication recommendation was more decisive than referee's academic productivity

    Implementación de una evaluación por competencias académicas en el pregrado de Economía de la Universidad del Magdalena, Colombia

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    RESUMEN: El objetivo de este artículo es presentar los resultados de una evaluación piloto en el enfoque de competencias académicas en el pregrado de Economía de la Universidad del Magdalena, aplicada para los cursos de Macroeconomía I, Estadística II, Finanzas Públicas y Economía Regional en el segundo semestre de 2018. Se muestra que una evaluación de este tipo arroja una medida sobre lo que un estudiante puede hacer con lo que aprendió. Así mismo, la metodología que permite definir las competencias de cada curso se establece en coherencia con el perfil profesional del pregrado. Este artículo contribuye a la literatura sobre la renovación de los métodos de evaluación en la educación superior en Colombia.ABSTARCT: This paper presents the results of an experimental test on proficiency-based assessment in Economics at University of Magdalena (Colombia), in the second half of 2018. The evaluation was carried out for Macroeconomics I, Statistics II and Public Finance and Regional Economics courses. After defining the competencies foreseen for each course based on the undergraduate student’s profile, the paper shows that this type of tests allows determining what a student can do with what they have learned. This paper contributes to the literature regarding the renewal of evaluation methods in higher education in Colombia

    Cierre Data Center Global Red

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    En la compañía Global Red se identificó la necesidad de cerrar su Data Center chapinero de 12 años de funcionamiento por obsolescencia tecnológica y por la venta del inmueble donde está ubicado, lo cual implica la migración de los clientes existentes a un nuevo centro de datos ubicado en Chicó, apagar toda la infraestructura tecnológica y electromecánica obsoleta, además la adecuación del área donde se encontraban los equipos y la disposición final de los desechos.The Global Red company identified the need to close its 12-year-old Chapinero Data Center due to technological obsolescence and the sale of the property where it is located, which implies the migration of existing clients to a new Data Center located in boy, turn off all the obsolete technological and electromechanical infrastructure, in addition to the adaptation of the area where the equipment was located and the final disposal of the waste

    Intermediate band solar cells. The transition metal supersaturated Silicon approach

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    Within the framework of the third solar cell generation some new ideas to enlarge the spectral response of the solar cells toward the infrared have been proposed. Among them the inclusion of an Intermediate Band (IB) seems to be very promising. This paper will deal with one of the ways to generate the IB namely the deep level center approach. We will discuss not only its existence but also the carriers lifetime recovery which is necessary to obtain the expected increase of the solar cell efficiency
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