Video streaming with quality adaption using collaborative active grid networks

Due to the services and demands of the end users, Distributed Computing (Grid Technology, Web Services, and Peer-to-Peer) has been developedrapidJy in thelastyears. Theconvergence of these architectures has been possible using mechanisms such as Collaborative work and Resources Sharing. Grid computing is a platform to enable flexible, secure, controlled, scalable, ubiquitous and heterogeneous services. On the other hand, Video Streaming applications demand a greater deployment over connected Internet users. The present work uses the Acti ve Grid technology as a fundamental platform to give a solution of multimediacontentrecovery. This solution takes into account the following key concepts: collaborative work, multi-source recovery and adapti ve quality. A new archi tecture is designed to deliver video content over a Grid Network. The acti ve and passi ve roles of the nodes are important to guarantee a high quality and efficiency for the video streaming system. The acti ve sender nodes are the content suppliers, while the passive sender nodes wiU perform the backup functions, based on global resource control policies. The aim of the backup node is minirnize the time to restore the systemin caseoffailures. In this way, all participant peers work in a collaborati ve manner following a mul ti -source recovery scheme. Furthermore, Video La yered Encoding is used to manage the video data in a high scalable way, di viding the video in multiple layers. This video codification scheme enables thequality adaptation according to the availability of system resources. In addition, a buffer by sender peer and by layer is needed for an effecti ve control ofthe video retrieve. The QoS will fit considering the state of each buffer and the measurement tools provide by the Acti ve Grid on the network nodes. Ke ywords: Peer -to-Peer Grid Architecture, Services for Active Grids, Streaming Media, Layered Coding, Quality Adaptation, CoUaborative Work.Peer Reviewe

Modelado semántico y ubicuo del comercio electrónico mediante Web Services

La demanda de interoperabilidad semántica y ubicuidad tecnológica en aplicaciones de comercio electrónico tiene un crecimiento exponencial. Añadir propiedades inteligentes a la Web actual, ya es una realidad a través del desarrollo e implementación de Web Services basados en estándares de fácil gestión y cada vez más estables, cumpliendo con los requerimientos básicos de Calidad de Servicio (QoS). Este trabajo presenta un análisis de la tecnología de los Web Services con el principal objetivo de aportar valor añadido a aplicaciones de Comercio Electrónico; así como, exponer una visión general del estado actual de los Web Services y sus contribuciones a las necesidades de las empresas en general.Peer Reviewe

Video streaming with quality adaption using collaborative active grid networks

Due to the services and demands of the end users, Distributed Computing (Grid Technology, Web Services, and Peer-to-Peer) has been developedrapidJy in thelastyears. Theconvergence of these architectures has been possible using mechanisms such as Collaborative work and Resources Sharing. Grid computing is a platform to enable flexible, secure, controlled, scalable, ubiquitous and heterogeneous services. On the other hand, Video Streaming applications demand a greater deployment over connected Internet users. The present work uses the Acti ve Grid technology as a fundamental platform to give a solution of multimediacontentrecovery. This solution takes into account the following key concepts: collaborative work, multi-source recovery and adapti ve quality. A new archi tecture is designed to deliver video content over a Grid Network. The acti ve and passi ve roles of the nodes are important to guarantee a high quality and efficiency for the video streaming system. The acti ve sender nodes are the content suppliers, while the passive sender nodes wiU perform the backup functions, based on global resource control policies. The aim of the backup node is minirnize the time to restore the systemin caseoffailures. In this way, all participant peers work in a collaborati ve manner following a mul ti -source recovery scheme. Furthermore, Video La yered Encoding is used to manage the video data in a high scalable way, di viding the video in multiple layers. This video codification scheme enables thequality adaptation according to the availability of system resources. In addition, a buffer by sender peer and by layer is needed for an effecti ve control ofthe video retrieve. The QoS will fit considering the state of each buffer and the measurement tools provide by the Acti ve Grid on the network nodes. Ke ywords: Peer -to-Peer Grid Architecture, Services for Active Grids, Streaming Media, Layered Coding, Quality Adaptation, CoUaborative Work.Peer Reviewe

Investigando narrativas de docentes en formación sobre política lingüística e identidad durante su práctica

ABSTRACT: This narrative inquiry aims to unveil the incorporation of policy agency within the construction of teacher identity of pre-service teachers in their academic practicums. Drawing on a critical-sociocultural approach to narrative inquiry, language policy, and teacher identity, the narratives of five students of an English teaching program in Medellín, Colombia, were examined. Their reflections and decision making on foreign language policies regulating their pedagogical practices at various schools show their social and critical awareness. Teaching represents a high moral load for them as they embrace a humanistic perspective. However, their narratives also pose challenges to language teaching programs in helping pre-service teachers to build micropolitical agency supported on solid theoretical knowledge to participate in policymaking. On the one hand, their narrations of the policy appropriation process they undertook show their frustration and disappointment in trying to participate when policy structures and other policy arbiters were close to them. On the other hand, when policy structures and arbiters openly allowed their policy participation, their actions and reflections focused on methodological concerns but rarely addressed social or critical awareness regarding curriculum design and development. Therefore, supporting pre-service teachers in strengthening their identities with solid theoretical constructs should be a priority because they will build micropolitical agency to overcome political tensions and negotiate their policy participation.RESUMEN: Esta investigación narrativa tiene como objetivo develar la incorporación de la agencia política dentro de la construcción de identidad docente de los docentes en formación en sus prácticas académicas. Partiendo de un enfoque crítico-sociocultural de investigación narrativa, política lingüística e identidad del maestro, se analizaron las narraciones de cinco estudiantes de una licenciatura en lenguas extranjeras con énfasis en inglés en Medellín. Sus reflexiones y decisiones sobre las políticas de lenguas extranjeras que regulan sus prácticas pedagógicas en varias escuelas muestran su conciencia social y crítica. La enseñanza representa una gran carga moral para ellos, pues adoptan una perspectiva humanista. Sin embargo, sus narrativas también plantean desafíos a los programas de enseñanza de idiomas al ayudar a los docentes en formación a construir una agencia micropolítica apoyada en conocimientos teóricos sólidos para participar en la creación de políticas. Por un lado, sus narraciones sobre el proceso de apropiación de políticas muestran su frustración y desilusión al intentar participar cuando las estructuras de políticas y otros árbitros de políticas se les cerraban. Por otro lado, cuando las estructuras políticas y los árbitros permitian abiertamente su participación política, sus acciones y reflexiones se centran en preocupaciones metodológicas, pero rara vez abordan la conciencia social o crítica con respecto al diseño y desarrollo del currículo. Por lo tanto, apoyar a los docentes en formación en el fortalecimiento de sus identidades con construcciones teóricas sólidas debería ser una prioridad porque construirán una agencia micropolítica para superar las tensiones políticas y negociar su participación política

La evasiva omnipresencia del inglés en la educación terciaria : el caso de Colombia

ABSTRACT: This article aims at describing how the educational actors of a private university make sense of language policies.The research was guided under a qualitative approach taking the historic-hermeneutic perspective as a paradigm. The data collected consists of news and information about the National Foreign Language Policy, the text corpus supporting the institutional policy, and semi-structured interviews. The results show how participants, albeit the pervasiveness of language policies in all the national educational system, conceive English far off from being necessary for professional life as the government intends. The study concluded that is imperative to take stances in the analysis and the enactment of language policies in order to obtain better results.RESUMEN: Este artículo tiene como objetivo describir cómo los actores educativos de una universidad apropian las políticas lingüísticas. La investigación se guió bajo un enfoque cualitativo tomando la perspectiva histórico-hermenéutica como paradigma. Los datos recopilados consisten en noticias e información sobre las políticas lingüísticas nacionales, el corpus de texto que respalda la política institucional y entrevistas semiestructuradas. Los resultados muestran cómo los participantes, a pesar de la omnipresencia de las políticas lingüísticas en todo el sistema educativo nacional, conciben el inglés lejos de ser necesario para la vida profesional como pretende el gobierno. El estudio concluyó que es imperativo adoptar posturas críticas en el análisis y la apropiación de políticas lingüísticas para obtener mejores resultados

Inherent Uncertainty in the Determination of Multiple Event Cross Sections in Radiation Tests

In radiation tests on SRAMs or FPGAs, two or more independent bitflips can be misled with a multiple event if they accidentally occur in neighbor cells. In the past, different tests such as the ``birthday statistics'' have been proposed to estimate the accuracy of the experimental results. In this paper, simple formulae are proposed to determine the expected number of false 2-bit and 3-bit MCUs from the number of bitflips, memory size and the method used to search multiple events. These expressions are validated using Monte Carlo simulations and experimental data. Also, a technique is proposed to refine experimental data and thus partially removing possible false events. Finally, it is demonstrated that there is a physical limit to determine the cross section of memories with arbitrary accuracy from a single experiment

Laser tests on a power operational amplifier

Laser tests on a power operational amplifier were performed to investigate its sensitivity to single event transients. These tests apparently point out to this device being quite insensitive to single event transients so it would become a good candidate to develop power systems to be used in radiation environments

Defining a strategy to perform life-tests with analog devices

Unlike for memory elements inside integrated circuits, scarce life tests have been performed to study single event transients in discrete analog devices. The reason is that life tests require a large amount of samples to be stored for having enough data allowing statistical conclusions and, usually, single event transients are captured by means of oscilloscopes. In this paper, we propose a strategy to carry out life tests in analog voltage comparators by means of digital programmable device that can detect anomalous pulses in the voltage comparator. Besides, the idea on which this kind of tests relies can be extended to be used with other families of analog devices, such as operational amplifiers, voltage references, etc

Principales fallas activas de las Cuencas de Granada y Guadix-Baza (Cordillera Bética)

The Granada and Guadix-Baza Basins, the largest Neogene-Quaternary intramontane basins of the Betic Cordillera (southern Spain), undergo active deformation with an associated moderate level of seismic activity. This deformation is controlled by a NNWSSE compressive regime and an approximate orthogonal tensional regime. The compression produced N70ºE to E-W folds of several scales, the Sierra Nevada antiform being the largest one. The tension is accommodated mainly by NW-SE active normal faults, the most notable being the Baza Fault, in the Guadix-Baza Basin, and the Granada, Sierra Elvira-Dílar and Padul-Dúrcal Faults, in the Granada Basin. In addition, other active faults with different orientations also exist, such as the Alfahuara-Botardo and the Galera faults in the Guadix-Baza Basin, and the Huenes, Obéilar-Pinos Puente and N of Sierra Tejeda Faults in the Granada Basin. Moreover, in several sectors, the presence of orthogonal normal fault sets suggests alternating trends or even radial extension. Slip rates of these active faults, based on geologic markers, vary between 0.06 and 0.5 mm/year. Estimates for the maximum expected magnitude of earthquakes caused by these faults vary between MW 6.0 and 7.0. The N of Sierra Tejeda and the Baza Faults, the largest faults in the Granada and Guadix-Baza Basins, respectively, have the greatest seismic potential. They could cause events up to a magnitude of MW 6.5-7.0, although their reference earthquakes, computed for a return period of 475 years, are on the order of MW 5.0-5.5.Las Cuencas de Granada y Guadix-Baza, las mayores cuencas intramontañosas del Neógeno y Cuaternario de la Cordillera Bética (sur de España), experimentan una deformación activa y tienen asociada una actividad sísmica moderada. La deformación está controlada por una compresión NNO-SSE y una tensión aproximadamente perpendicular. La compresión ha formado pliegues de dirección N70ºE a E-O de muy diferentes tamaños, siendo el antiforme de Sierra Nevada el mayor. La tensión se acomoda sobre todo por fallas normales NO-SE, siendo las más notables de ellas la falla de Baza, en la cuenca de Guadix-Baza, y las de Granada, Sierra Elvira-Dílar y Padul-Dúrcal, en la cuenca de Granada. Además, existen otras fallas activas con diferentes orientaciones, tales como la de Alfahuara-Botardo y la de Galera en la cuenca de Guadix-Baza y las de Huenes, Obéilar-Pinos Puente y norte de Sierra Tejeda en la cuenca de Granada. Además, en varios sectores, la presencia de juegos de fallas ortogonales sugiere cambios en el elipsoide de esfuerzos e incluso una extensión radial. Las tasas de desplazamiento de estas fallas activas, calculadas a partir de marcadores geológicos, varían entre 0,06 y 0,5 mm/año. La estimación del potencial sísmico indica que la máxima magnitud esperable de los terremotos producidos por estas fallas varía entre MW 6,0 y 7,0. La falla del N de Sierra Tejeda y la de Baza, las mayores respectivamente en las Cuencas de Granada y Guadix-Baza, tienen el mayor potencial sísmico. Podrían causar eventos con magnitudes del orden de MW 6,5-7,0, aunque sus terremotos de referencia para un periodo de retorno de 475 años son del orden de MW 5,0-5,5.This work has been financed through projects TOPO-IBERIA CONSOLIDER-INGENIO (CSD2006-00041), CGL2010-21048, CGL-2011-29920, CGL2011-30153-C02-02, P09-RNM-5388 and the Junta de Andalucía groups RNM 370, RNM148 and RNM325

Single Event Upsets under 14-MeV Neutrons in a 28-nm SRAM-based FPGA in Static Mode

A sensitivity characterization of a Xilinx Artix-7 FPGA against 14.2 MeV neutrons is presented. The content of the internal SRAMs and flip-flops were downloaded in a PC and compared with a golden version of it. Flipped cells were identified and classified as cells of the configuration RAM, BRAM, or flip-flops. SBUs and MCUs with multiplicities ranging from 2 to 8 were identified using a statistical method. Possible shapes of multiple events are also investigated, showing a trend to follow wordlines. Finally, MUSCA SEP3 was used to make assesment for actual environments and an improvement of SEU injection test is proposed