IKASNABAR 2014 International Conference. Microcontents, miniMOOCs and mLearning

[ES]Ikasnabar es una conferencia para hablar de tendencias en educación, sobre las nuevas tecnologías en el ámbito educativo y conocer personas que están generando buenas ideas y prácticas en su quehacer diario. Este libro intenta recoger todo ello con las contribuciones de autores noveles y de renombre que buscan la excelencia en los procesos de enseñanza-aprendizaje. Tres tendencias importantes de aprendizaje se están expandiendo. Microcontenidos, aprendizaje móvil y MOOCs son la cara de una misma moneda: microaprendizaje con contenido rico, abierto y desmenuzado. A medida que el consumo de Internet desde dispositivos móviles aumenta, el aprendizaje móvil con tecnologías como HTML5, software para MOOC, plataformas de contenidos de vídeo, etc., están siendo algunas de las claves de la nueva revolución en el ámbito educativo. El microcontenido hace referencia a los pequeños trozos de información digital en un estado permanente de flujo y circulación. Es a menudo un único tema, limitado en longitud, que se consume rápidamente y con frecuencia limitado por el software o por el dispositivo. Se trata de la puesta en común de recursos. Se basa en la interacción humano-a-humano con los medios de comunicación de Internet. El otro tema central de esta conferencia es el de los MOOC realizados por los profesores que quieren tomar ventaja en el comienzo de esta nueva era de la educación abierta con calidad. MOOCs son, básicamente, cursos abiertos y es necesario recordar los puntos esenciales de este tipo de instrucción. Los miniMOOCs son alternativas con menos horas en el proceso de aprendizaje. Hoy en día, un buen MOOC podrá ser la mejor tarjeta de presentación para profesores, expertos y estudiantes. Vivimos en tiempos de cambio con ámbitos en los que se mezcla el aprendizaje formal e informal, y las universidades y colegios deberíamos estar atentos a esto.

Improving Content Delivery Efficiency through Multi-Layer Mobile Edge Adaptation

This paper presents a novel architecture for optimizing the HTTP-based multimedia delivery in multi-user mobile networks. This proposal combines the usual client-driven dynamic adaptation scheme DASH-3GPP with network-assisted adaptation capabilities, in order to maximize the overall Quality of Experience. The foundation of this combined adaptation scheme is based on two state of the art technologies. On one hand, adaptive HTTP streaming with multi-layer encoding allows efficient media delivery and improves the experienced media quality in highly dynamic channels. Additionally, it enables the possibility to implement network-level adaptations for better coping with multi-user scenarios. On the other hand, mobile edge computing facilitates the deployment of mobile services close to the user. This approach brings new possibilities in modern and future mobile networks, such as close to zero delays and awareness of the radio status. The proposal in this paper introduces a novel element, denoted as Mobile Edge-DASH Adaptation Function, which combines all these advantages to support efficient media delivery in mobile multi-user scenarios. Furthermore, we evaluate the performance enhancements of this content- and user context-aware scheme through simulations of a mobile multimedia scenario.

Radio-aware service-level scheduling to minimize downlink traffic delay through Mobile Edge Computing

One of the most challenging problems in mobile broadband networks is how to assign the available radio resources among the different mobile users. Traditionally, research proposals are either speci c to some type of traffic or deal with computationally intensive algorithms aimed at optimizing the delivery of general purpose traffic. Consequently, commercial networks do not incorporate these mechanisms due to the limited hardware resources at the mobile edge. Emerging 5G architectures introduce cloud computing principles to add flexible computational resources to Radio Access Networks. This paper makes use of the Mobile Edge Computing concepts to introduce a new element, denoted as Mobile Edge Scheduler, aimed at minimizing the mean delay of general traffic flows in the LTE downlink. This element runs close to the eNodeB element and implements a novel flow-aware and channel-aware scheduling policy in order to accommodate the transmissions to the available channel quality of end users.

Solutions for New Terrestrial Broadcasting Systems Offering Simultaneously Stationary and Mobile Services

221 p.

Structural Synthesis of 3-DoF Spatial Fully Parallel Manipulators

In this paper, the architectures of three degrees of freedom (3-DoF) spatial, fully parallel manipulators (PMs), whose limbs are structurally identical, are obtained systematically. To do this, the methodology followed makes use of the concepts of the displacement group theory of rigid body motion. This theory works with so-called 'motion generators'. That is, every limb is a kinematic chain that produces a certain type of displacement in the mobile platform or end-effector. The laws of group algebra will determine the actual motion pattern of the end-effector. The structural synthesis is a combinatorial process of different kinematic chains' topologies employed in order to get all of the 3-DoF motion pattern possibilities in the end-effector of the fully parallel manipulator.

Modelling and Simulation of ERTMS for Current and Future Mobile Technologies

Nowadays, train control in-lab simulation tools play a crucial role in reducing extensive and expensive on-site railway testing activities. In this paper, we present our contribution in this arena by detailing the internals of our European Railway Train Management System in-lab demonstrator. This demonstrator is built over a general-purpose simulation framework, Riverbed Modeler, previously Opnet Modeler. Our framework models both ERTMS subsystems, the Automatic Train Protection application layer based on movement authority message exchange and the telecommunication subsystem based on GSM-R communication technology. We provide detailed information on our modelling strategy. We also validate our simulation framework with real trace data. To conclude, under current industry migration scenario from GSM-R legacy obsolescence to IP-based heterogeneous technologies, our simulation framework represents a singular tool to railway operators. As an example, we present the assessment of related performance indicators for a specific railway network using a candidate replacement technology, LTE, versus current legacy technology. To the best of our knowledge, there is no similar initiative able to measure the impact of the telecommunication subsystem in the railway network availability.

Algum lugar, lugar algum

A presente dissertação de mestrado propõe uma reflexão sobre os lugares da arte no contexto de um mundo globalizado em que o deslocamento se coloca como uma questão fundamental em diversas esferas da vida, dos homens, das coisas. Nesse mundo da mobilidade física ou virtual, concreta ou imaterial, objetiva ou simbólica, as obras de arte percorrem caminhos diversos e nos interrogam sobre como suportam, em seus deslocamentos, serem carregadas de um sistema de visibilidade para outro. O artista assume diferentes papéis e se relaciona com as questões da arte a partir de perspectivas móveis. Quando se deslocam artista e obra partem de um lugar conhecido e se movem para desconhecer. Caminham por Algum Lugar para chegar a Lugar Algum. Com o objetivo de especular sobre o que chamei de Algum Lugar, Lugar Algum, construo uma sequência de ações possíveis: caminhar, parar, compartilhar / perceber, imaginar / modificar, inventar, re-significar / afastar, aproximar / entrar, sair. Construir meu trabalho é orientar-me por um conjunto de ações em aberto nem sempre na mesma ordem. Como estratégia, exercito a ação de mover-me por lugares desconhecidos e busco manter sempre aumentado o meu nível de percepção dos lugares por onde passo. Uso meu corpo como um mediador sensível e me permito ser afetada. Procuro, de forma proposital, variar entre o estado de conhecer e de desconhecer. Trabalho a partir do cotidiano para tirar dele o que se mostre saliente e para me dedicar a reinventar lugares com o meu corpo e na minha mente. Ao relacionar a geografia do que está visível com um amplo universo que ainda se encontra num estado de vir a ser, coloco-me diante de uma geografia imaginária, busco uma forma de continuar infinitamente a construir hipóteses sobre Algum Lugar. Através de relações entre o meu processo de trabalho e algumas obras de artistas contemporâneos procuro estabelecer conexões que contribuam para deixar em aberto um campo potencial de investigações sobre os lugares da arte

Studying the influence of substitutional elements on mechanical behavior of Alloy 718

In nickel-based superalloys, substitutional solute species have a strong impact on in service mechanical properties as well as on oxidation and corrosion resistances. In alloy 718, recent studies carried out by tensile tests highlighted the fact that refractory solute species are able to interact strongly with mobile dislocations during plastic deformation, generating dynamic strain ageing, and, in wide ranges of tests temperatures and strain rates, Portevin-Le Chatelier effect. The precise nature of the substitutional element responsible for such a dynamic interaction is still subject to debate. We addressed this question by means of mechanical spectroscopy studies of alloy 718 and various related alloys corresponding to monitored changes in the chemical composition. Only a single internal friction relaxation peak has been observed for all the studied alloys. By analyzing the damping behavior of these alloys at different imposed solicitation frequencies by sweeping a large temperatures range, the activation energies of the relaxation process and the type of mechanism involved have been determined. The process is a "Zener relaxation" in the alloys, i.e. a substitutional atoms dipole reorientation under applied stress. The results tend to prove that Niobium is not involved in the relaxation process whereas Molybdenum content seems to play an important role in the relaxation intensity.