Search results for "TELECOMUNICACIONES"
showing 10 items of 51 documents
Analysis of Multipactor Effect in a Partially Dielectric-Loaded Rectangular Waveguide
2019
This paper 1 presents a study of the multipactor 2 effect in a partially dielectric-loaded rectangular waveguide. 3 To obtain the simulations presented in this paper, a detailed 4 analysis of the dynamics of the electron inside this waveguide 5 has been performed, taking into account the radio frequency 6 electromagnetic fields propagating in the waveguide and the dc 7 electric field that appears because of the charging of the dielectric 8 layer. This electrostatic field is obtained by computing the electric 9 potential produced by an arbitrary charge distribution on the 10 dielectric layer in a dielectric-loaded waveguide. The electron 11 trajectory is then found by numerically solving the…
Sombras en Lisboa
2000
La convergencia de las telecomunicaciones, los medios de comunicación y las tecnologías de la información
2020
Europa vive en un punto de inflexión histórico sin parangón. El surgimiento, en el siglo XXI, de lo que se conoce como la Cuarta Revolución Industrial no oculta el hecho de que no solo las telecomunicaciones, sino también los medios de comunicación y las tecnologías de la información se enfrentan a nuevos desafíos en un escenario global. El traje original, especialmente diseñado para los medios de comunicación y las telecomunicaciones, se está volviendo pequeño como resultado de un fenómeno que ha marcado un momento decisivo entre los dos sectores, internet. En consecuencia, en el presente estudio se intenta representar los retos a los que se enfrenta el legislador ante el surgimiento de la…
Assessing the Impact of Temporary Retail Price Discounts Intervals Using SVM Semiparametric Regression
2009
Although the marketing literature has found that temporary retail price discounts cause a significant sales increase, little is known about the specific characteristics of deals that influence the magnitude of the sales spike. In this paper, we analyse the impact of the length of temporary retail price discounts periods on the sales increase using scanner-store daily-sales data for two frequently purchased product categories: ground coffee (a storable category) and yogurt (a perishable category).Wedevelop a robust semiparametric regression model based on support vector statistical theory with several previously proposed predictors along with a daily time description. This model also makes i…
Non-convex distributed power allocation games in cognitive radio networks
2013
In this thesis, we explore interweave communication systems in cognitive radio networks where the overall objective is to maximize the sum-rate of each cognitive radio user by optimizing jointly both the detection operation based on sensing and the power allocation across channels, taking into account the influence of the sensing accuracy and the interference limitation to the primary users. The optimization problem is addressed in single and multiuser cognitive radio networks for both single-input single-output and multi-input multi-output channels. Firstly, we study the resource allocation optimization problem for single-input single-output single user cognitive radio networks, wherein th…
Neutrino interaction classification with a convolutional neural network in the DUNE far detector
2020
The Deep Underground Neutrino Experiment is a next-generation neutrino oscillation experiment that aims to measure CP-violation in the neutrino sector as part of a wider physics program. A deep learning approach based on a convolutional neural network has been developed to provide highly efficient and pure selections of electron neutrino and muon neutrino charged-current interactions. The electron neutrino (antineutrino) selection efficiency peaks at 90% (94%) and exceeds 85% (90%) for reconstructed neutrino energies between 2–5 GeV. The muon neutrino (antineutrino) event selection is found to have a maximum efficiency of 96% (97%) and exceeds 90% (95%) efficiency for reconstructed neutrino…
Using Daily Store-level Data to Understand Price Promotion Effects in a Semiparametric Regression Model
2009
Though it has been widely reported in the marketing literature that temporary price discounts generate substantial short-term sales increase, the shape of the deal effect curve constitutes a key research topic, for which there are still limited empirical results. To address this issue, a semiparametric regression approach is used to model the complex nature of this phenomenon. Our model is developed at the brand level using daily store-level scanner-data, which allows the study of several nonreported promotional effects, such as the influence of the day of the week both in promotional and nonpromotional periods. The results show that the weekend is the most effective in increasing promotion…
Conversión de formatos de proyección y codificación basada en campo de visión para streaming adaptativo de videos 360º utilizando DASH
2019
En este trabajo final de grado se ha extendido una plataforma extremo-a-extremo para la preparación, distribución y reproducción de vídeos 360º con tal de poder adoptar proyecciones CMP homogéneas, existentes hasta la fecha, además de otras configuraciones más avanzadas que permiten concentrar la resolución en áreas concretas del video 360º. In this final degree project, an end-to-end platform has been extended for the preparation, distribution and playback of 360º videos in order to be able to adopt homogeneous CMP projections, existing to date, in addition to other more advanced configurations that allow concentrating the resolution in specific areas of the 360º video.
Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles
2009
[EN] A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green's function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed…