Search results for "WIDE"
showing 10 items of 1235 documents
Teaching in times of COVID-19: determinants of teachers' educational technology use
2021
We conduct a large and nationwide survey among German teachers to investigate the determinants of teachers' adaption to an increased use of educational technology during the COVID-19 school closure...
Renewable electricity producing technologies and metal depletion: A sensitivity analysis using the EROI
2015
International audience; More and more attention is being paid to renewable technologies because they are seen as a great opportunity to disengage our society from its dependence on fossil fuels. Such flow-based energy resources that rely on solarenergy are supposed to lead us toward a sustainable energy future. However, because of their high capitalintensity, renewable technologies require large amounts of matter, including both common and rare metals.These metals require energy for their production, and more specifically for their extraction. The energy costassociated with metal extraction is linked to mineral ore grade, meaning that as depletion progresses, energycost increases. In additi…
Implantación de recursos didácticos digitales en asignaturas de Organización de Empresas
2013
El objetivo de este artículo es presentar el protocolo de implantación de diversas herramientas didácticas, así como el nivel de satisfacción de los estudiantes que las utilizan. Los resultados muestran, primero, que no es posible crear un único protocolo aplicable a todos los recursos, debido a las diferencias en los objetivos didácticos existentes. Segundo, la valoración que los estudiantes hacen de la utilización de los recursos es muy positiva, aunque existen algunas diferencias entre las distintas herramientas. Estos resultados permiten mejorar los recursos y adecuarlos al perfil de los estudiantes para que éstos puedan sacar el mayor provecho posible.
Open Access E-Journals : past, present, and future
2015
Comienza este artículo trazando el origen y desarrollo de las revistas electrónicas en acceso abierto, cómo surgieron, se fueron definiendo y a qué necesidades respondieron. Se explica cómo se produjo la transición del mundo impreso al electrónico en el diseño y concepción de las revistas; y se señala exactamente cuando se produjo el despegue de este tipo de publicaciones. Para describir la situación actual de las revistas se recurre a los datos proporcionados por el directorio de publicaciones electrónicas Ulrichs y al directorio de revistas en acceso abierto DOAJ. Se calcula el número de revistas circulantes y se ofrece un retrato del perfil editorial de las revistas a día de hoy. Se desc…
Residual strain effects on the two-dimensional electron gas concentration of AlGaN/GaN heterostructures
2001
Ga-face AlGaN/GaN heterostructures with different sheet carrier concentrations have been studied by photoluminescence and Raman spectroscopy. Compared to bulk GaN, an energy shift of the excitonic emission lines towards higher energies was observed, indicating the presence of residual compressive strain in the GaN layer. This strain was confirmed by the shift of the E2 Raman line, from which biaxial compressive stresses ranging between 0.34 and 1.7 GPa were deduced. The spontaneous and piezoelectric polarizations for each layer of the heterostructures have been also calculated. The analysis of these quantities clarified the influence of the residual stress on the sheet electron concentratio…
APIS to extract information in social channels in educational context
2018
In this days the world is involved in the research and development of new resources, and methods that allow the use of new technologies fulfilling a goal that is the learning of education through the Web, thus using resources such as different APIs for different purposes. Taking into account the functionalities provided by the APIs, the objective was to obtain information about the different educational resources in the social channels of the Universidad Tecnica Particular de Loja (UTPL). The study of pervious APIs is a part of the project Use of Cloud Computing tools, Bodies of Knowledge and affective computing in the process of developing technological skills focused on problem solving of…
A Data-Driven Approach to Dynamically Learn Focused Lexicons for Recognizing Emotions in Social Network Streams
2016
Opinion Mining aims at identifying and classifying subjective information in a collection of documents. A variety of approach exists in literature, ranging from Supervised Learning to Unsupervised Learning. Currently, one of the biggest opinion resource of opinionated texts existing on the Web is represented by Social Networks. Networks are not only a vast collection of documents but they also represent a dynamic evolving resource as the users keep posting their own opinions. We based our work relying on this idea of dynamicity, building an evolving model that updates itself in real time as users submit their posts. This is done through a set of supervised techniques based on a Lexi- con of…
Design of Wideband MIMO Car-to-Car Channel Models Based on the Geometrical Street Scattering Model
2012
Published version of an article in the journal: Modelling and Simulation in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2012/264213 Open access We propose a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. The proposed channel model assumes an infinite number of scatterers, which are uniformly distributed in two rectangular areas located on both sides of the street. Analytical solutions a…
A Novel Wideband MIMO Car-to-Car Channel Model Based on a Geometrical Semi-Circular Tunnel Scattering Model
2016
In this paper, we present a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on a geometrical semi-circular tunnel (SCT) scattering model. From the geometrical SCT scattering model, a reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. In the proposed reference channel model, it is assumed that an infinite number of scatterers are randomly distributed on the tunnel wall. Starting from the geometrical scattering model, the time-variant transfer function (TVTF) is derived, and its correlation properties in time, frequency, and space are studied. Expressions ar…
From technology engineering to social engineering
2007
Virtual worlds have a long history, and it also includes various technologies. Yet research interest towards them has diverged over the years. It seems that nowadays they are on focus again with the evolution of socially oriented and community-supporting virtual worlds. Instead of technical factors, human factors and the motivation behind the use are highlighted. In this paper, we will briefly review the research efforts made in the 90's, and derive a set of themes that were of interest back then. Next, we will expand the set by arguing for newer themes, identified in the latest information systems literature. These two sets of themes form a basis of a research agenda for studying virtual w…