Search results for "TELECOMUNICACIONES"
showing 10 items of 51 documents
Engineering multi-agent systems: State of affairs and the road ahead
2019
International audience; The continuous integration of software-intensive systems together with the ever-increasing computing power offer a breeding ground for intelligent agents and multi-agent systems (MAS) more than ever before. Over the past two decades, a wide variety of languages, models, techniques and methodologies have been proposed to engineer agents and MAS. Despite this substantial body of knowledge and expertise, the systematic engineering of large-scale and open MAS still poses many challenges. Researchers and engineers still face fundamental questions regarding theories, architectures, languages, processes, and platforms for designing, implementing, running, maintaining, and e…
Analyses of Dual Polarization WDM and SCM Radio over Fiber and Radio over FSO for C-RAN Architecture
2016
En este trabajo se simulan y verifican experimentalmente los esquemas de transmisión para una Arquitectura de Red de Acceso Radio Centralizada (C-RAN) basados en la combinación de dos tecnologías: Radio sobre Fibra (RoF) y Radio sobre FSO (RoFSO). Las configuraciones propuestas se optimizan para la evolución a largo plazo (LTE) con un ancho de banda de 20 MHz utilizando una modulación de amplitud en cuadratura de 64-QAM en términos de magnitud de vector de error (EVM). En primer lugar, se comparan las mediciones de la multiplexación por división de polarización mediante la combinación de RoF y RoFSO (PDM-RoF/FSO) con los modelos de simulación. Esto se amplía con la combinación de PDM-Multip…
Detection of Signals in MC–CDMA Using a Novel Iterative Block Decision Feedback Equalizer
2022
This paper presents a technique to mitigate multiple access interference (MAI) in multicarrier code division multiple access (MC-CDMA) wireless communications systems. Although under normal circumstances the MC-CDMA system can achieve high spectral efficiency and resistance towards inter symbol interference (ISI) however when exposed to substantial nonlinear distortion the issue of MAI manifests. Such distortion results when the power amplifiers are driven into saturation or when the transmit signal experiences extreme adverse channel conditions. The proposed technique uses a modified iterative block decision feedback equalizer (IB-DFE) that uses a minimal mean square error (MMSE) receiver …
Multimedia Retrieval by Means of Merge of Results from Textual and Content Based Retrieval Subsystems
2010
The main goal of this paper it is to present our experiments in ImageCLEF 2009 Campaign (photo retrieval task). In 2008 we proved empirically that the Text-based Image Retrieval (TBIR) methods defeats the Content-based Image Retrieval CBIR "quality" of results, so this time we developed several experiments in which the CBIR helps the TBIR. The TBIR System [6] main improvement is the named-entity sub-module. In case of the CBIR system [3] the number of low-level features has been increased from the 68 component used at ImageCLEF 2008 up to 114 components, and only the Mahalanobis distance has been used. We propose an ad-hoc management of the topics delivered, and the generation of XML struct…
Some Results Using Different Approaches to Merge Visual and Text-Based Features in CLEF’08 Photo Collection
2009
This paper describes the participation of the MIRACLE team at the ImageCLEF Photographic Retrieval task of CLEF 2008. We succeeded in submitting 41 runs. Obtained results from text-based retrieval are better than content-based as previous experiments in the MIRACLE team campaigns [5, 6] using different software. Our main aim was to experiment with several merging approaches to fuse text-based retrieval and content-based retrieval results, and it happened that we improve the text-based baseline when applying one of the three merging algorithms, although visual results are lower than textual ones.
Aprendizaje basado en proyectos en los laboratorios de comunicaciones digitales
2019
[EN] Digital Communications and Signal Processing for Communications have been traditionally taught from a theoretical point of view. The complexity and cost of radio-frequency systems hampers the realization of practical experiences in the laboratories of Communications. However, current Academic Accreditation includes the dimension of “what students are expected to be able to do”. The decrease of the gap between standard simulated laboratory sessions and more practical and realistic approaches is therefore required. In this paper, we introduce an active learning methodology we have followed in order to introduce practical aspects related to Digital Communications and Signal Processing for…
Desarrollo y análisis de sensores inalámbricos y sistemas asociados de IoT
2023
En los últimos años, la tecnología del Internet de las cosas (IoT) se ha vuelto cada vez más importante. Al ofrecer un medio para conectar dispositivos y establecer conexiones en tiempo real, el IoT ha facilitado el monitoreo y la gestión de entidades tangibles, como electrodomésticos, vehículos y edificios. Típicamente, un sistema IoT incorpora numerosos dispositivos que se comunican entre sí a través de gateways y servidores en la nube que alojan aplicaciones web y móviles. Los usuarios finales pueden interactuar sin problemas con sus dispositivos IoT, lo que les otorga una mayor accesibilidad y conveniencia. Dado su capacidad para proporcionar control y automatización en tiempo real, el …
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…
Evaluating temporary retail price discounts using semiparametric regression
2009
PurposeTo analyze the impact of temporary retail price discount on a consumer goods product category using semiparametric regression and considering different promotional price discount characteristics as well as brand characteristics.Design/methodology/approachA semiparametric regression model using Support Vector Machines, which aim to evaluate retailers' decisions about temporary price discounts, has been developed. The model is derived from the analysis of historical sales data, which provide precise evaluation of previous temporary price discounts periods. The model is also consistent with ample empirical evidence showing that historical retail sales data can be used to evaluate the im…
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…