An energy-efficient distributed dynamic bandwidth allocation algorithm for Passive Optical Access Networks

The rapid deployment of passive optical access networks (PONs) increases the global energy consumption of networking infrastructure. This paper focuses on the minimization of energy consumption in Ethernet PONs (EPONs). We present an energy-efficient, distributed dynamic bandwidth allocation (DBA) algorithm able to power off the transmitter and receiver of an optical network unit (ONU) when there is no upstream or downstream traffic. Our main contribution is combining the advantages of a distributed DBA (namely, a smaller packet delay compared to centralized DBAs, due to less time being needed to allocate the transmission slot) with energy saving features (that come at a price of longer delays due to the longer queue waiting times when transmitters are switched off). The proposed algorithm analyzes the queue size of the ONUs in order to switch them to doze/sleep mode when there is no upstream/downstream traffic in the network, respectively. Our results show that we minimized the ONU energy consumption across a wide range of network loads while keeping delay bounded.Postprint (published version

Ladrillo cerámico con huecos hexagonales

Ladrillo cerámico con huecos hexagonales. La invención consiste en un ladrillo cerámico con huecos hexagonales a lo largo de su dirección longitudinal. Resuelve el problema de la transmisión de ruido aéreo que presentan los ladrillos cerámicos con hueco cuadrado o rectangular. La intensidad del sonido transmitido en sólidos decrece con el aumento de camino recorrido. Por ello, la sustitución de las paredes perpendiculares que definen los huecos cuadrados o rectangulares, por las que definen los huecos hexagonales representa un mayor recorrido y una absorción mayor de ruido. El espesor del ladrillo puede variar según contenga una o más filas de hexágonos compartiendo caras o vértices. No hay limitación en las dimensiones del largo y ancho del mismo. Exteriormente los cantos de las piezas pueden ser machihembrados y las caras planas pueden o no presentar estriado. La colocación de la pieza se realiza con los huecos paralelos a la horizontal. Utilización en construcción de paramentos verticales en edificio

Trace Ethnography Workshop: iConference 2015

This workshop introduces participants to trace ethnography, building a network of scholars interested in the collection and interpretation of trace data and distributed documentary practices. The intended audience is broad, and participants need not have any existing experience working with trace data from either qualitative or quantitative approaches. The workshop provides an interactive introduction to the background, theories, methods, and applications–present and future–of trace ethnography. Participants with more experience in this area will demonstrate how they apply these techniques in their own research, discussing various issues as they arise. The workshop is intended to help researchers identify documentary traces, plan for their collection and analysis, and further formulate trace ethnography as it is currently conceived. In all, this workshop will support the advancement of boundaries, theories, concepts, and applications in trace ethnography, identifying the diversity of approaches that can be assembled around the idea of ‘trace ethnography’ within the iSchool community

New designs of the ceramic bricks of horizontal hexagonal hollow

This article is intended to state that Technical Drawing is a multiple tool of expression and communication essential to develop inquiry processes, the scientifically basis and comprehension of drawings and technological designs that can be manufactured. We demonstrate graphically and analytically that spatial vision and graphic thinking allow us to identify graphically real life problems, develop proposals of solutions to be analysed from different points of view, plan and develop the project, provide information needed to make decisions on objects and technological processes. From the knowledge of Technical Drawing and CAD tools we have developed graphic analyses to improve and optimize our proposed modification of the geometry of the rectangular cells of conventional bricks by hexagonal cells, which is protected by a Spanish patent owned by the Polytechnic University of Madrid. This new internal geometry of the bricks will improve the efficiency and the acoustic damping of walls built with the ceramic bricks of horizontal hollow, maintaining the same size of the conventional bricks, without increasing costs either in the manufacture and the sale. A single brick will achieve the width equivalent to more than FOUR conventional bricks

La información en la TDT interactiva : una oferta incipiente para unas prácticas periodísticas en transformación

This article presents the results of an exploration of the applications of an informative nature which are offered as part of the interactive services of the TDT (terrestrial digital television). It contains data about the weight which said applications have in the television offer, a description of the elements which compose them and a portrait of the productive dynamics that they generate. The work is based on the idea that the adequate and efficient development of TDT in Spain can only be achieved with a commitment to offering the audience quality interactive services and contents whether associated with the different genres of programs or not

A P4-Based PON architecture for 5G

Postprint (author's final draft

La publicidad televisiva ante el reto de la interactividad

Este artículo presenta una propuesta de clasificación de las diferentes formas que adopta la publicidad para incorporar la interactividad a sus estrategias comunicativas. La tipología nace de la observación y análisis de los modelos existentes y se presenta como instrumento que facilite la comprensión del fenómeno de la interactividad aplicada a la publicidad, ya sea en sus manifestaciones actuales como en aquellas que, en un futuro, puedan derivarseThis article presents a proposal for the classification of the different forms used in advertising to include interactivity in communication strategies. This typology is the result of the observation and analysis of existing models and is presented as an instrument that should help develop an understanding of the phenomenon of interactivity when applied to advertising, both in its current forms and in other forms that might be derived from them in the futur