Search results for "Telecomunicaciones"
showing 10 items of 51 documents
ZnMgO-based UV photodiodes: a comparison of films grown by spray pyrolysis and MBE
2016
Detecting the UV part of the spectrum is fundamental for a wide range of applications where ZnMgO has the potential to play a central role. The shortest achievable wavelength is a function of the Mg content in the films, which in turn is dependent on the growth technique. Moreover, increasing Mg contents lead to an electrical compensation of the films, which directly affects the responsivity of the photodetectors. In addition, the metal-semiconductor interface and the presence of grain boundaries have a direct impact on the responsivity through different gain mechanisms. In this work, we review the development of ZnMgO UV Schottky photodiodes using molecular beam epitaxy and spray pyrolysis…
Optical properties and microstructure of 2.02-3.30 eV ZnCdO nanowires: effect of thermal annealing
2013
International audience; ZnCdO nanowires with up to 45% Cd are demonstrated showing room temperature photoluminescence (PL) down to 2.02 eV and a radiative efficiency similar to that of ZnO nanowires. Analysis of the microstructure in individual nanowires confirms the presence of a single wurtzite phase even at the highest Cd contents, with a homogeneous distribution of Cd both in the longitudinal and transverse directions. Thermal annealing at 550 C yields an overall improvement of the PL, which is blue-shifted as a result of the homogeneous decrease of Cd throughout the nanowire, but the single wurtzite structure is fully maintained.
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.
Web Support for weight-loss interventions: PREDIRCAM2 clinical trial baseline characteristics and preliminary results
2018
An ongoing clinical trial is testing the efficacy of web telematic support in a structured program for obesity treatment and diabetes prevention. Participants were recruited from two tertiary-care hospitals and randomized to receive either a telematic intervention (TI) supported by PREDIRCAM2 web platform or a non-telematic intervention (NTI). All receive 1-year follow-up. Both interventions consist of tailored dietary and exercise prescriptions, based on a Mediterranean dietary pattern and general WHO exercise recommendations for adults. At 6 months, both groups have received 7 contacts, 3 exclusively telematic for the TI group. This is a preliminary result intention-to-treat analysis. One…
Incorporando dispositivos de radio definida por software en la materia de Comunicaciones Digitales: del grupo piloto a la gran clase
2020
La innovación educativa es un proceso que se extiende más allá de un curso académico. En su desarrollo se distinguen las etapas de planificación, implementación, evaluación y realimentación, para identificar aspectos susceptibles de mejora. En esta contribución presentamos el trabajo desarrollado en los dos últimos cursos en la asignatura Teoría de la Comunicación (materia de Comunicaciones Digitales), Grado en Ingeniería Telemática, de la Universitat de València. Concretamente, se incorporan dispositivos de radio definida por software en los laboratorios como herramienta para conseguir unas prácticas más realistas. El artículo describe el proceso de adaptación de una sesión de laboratorio, qu…
Sparse Deconvolution Using Support Vector Machines
2008
Sparse deconvolution is a classical subject in digital signal processing, having many practical applications. Support vector machine (SVM) algorithms show a series of characteristics, such as sparse solutions and implicit regularization, which make them attractive for solving sparse deconvolution problems. Here, a sparse deconvolution algorithm based on the SVM framework for signal processing is presented and analyzed, including comparative evaluations of its performance from the points of view of estimation and detection capabilities, and of robustness with respect to non-Gaussian additive noise. Publicado
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…
Upport vector machines for nonlinear kernel ARMA system identification.
2006
Nonlinear system identification based on support vector machines (SVM) has been usually addressed by means of the standard SVM regression (SVR), which can be seen as an implicit nonlinear autoregressive and moving average (ARMA) model in some reproducing kernel Hilbert space (RKHS). The proposal of this letter is twofold. First, the explicit consideration of an ARMA model in an RKHS (SVM-ARMA 2k) is proposed. We show that stating the ARMA equations in an RKHS leads to solving the regularized normal equations in that RKHS, in terms of the autocorrelation and cross correlation of the (nonlinearly) transformed input and output discrete time processes. Second, a general class of SVM-based syste…
Kernel-Based Framework for Multitemporal and Multisource Remote Sensing Data Classification and Change Detection
2008
The multitemporal classification of remote sensing images is a challenging problem, in which the efficient combination of different sources of information (e.g., temporal, contextual, or multisensor) can improve the results. In this paper, we present a general framework based on kernel methods for the integration of heterogeneous sources of information. Using the theoretical principles in this framework, three main contributions are presented. First, a novel family of kernel-based methods for multitemporal classification of remote sensing images is presented. The second contribution is the development of nonlinear kernel classifiers for the well-known difference and ratioing change detectio…
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…