A Study of Accessibility Requirements for Media Players on the Web

Proceedings of: The 6th International Conference on Universal Access in Human–Computer Interaction (UAHCI 2011), held as part of The 14th International Conference on Human–Computer Interaction (HCI International 2011), Orlando (FL, USA), July 9-14, 2011Multimedia content covers the Web, and we should provide access to all people. For this reason, we must consider including accessibility requirements in a synchronized manner with the alternative resources such as caption and audio description among others. In addition, it is very important to take into account accessibility requirements in the player to avoid barriers and to ensure access to this multimedia content as well as their resources. This paper presents an overall study on standards and players with accessibility requirements. Moreover, solutions to improve the accessibility features in the YouTube player are presented. Based on this study, we have distinguished a set of guidelines to take into account for including accessibility requirements in players. Furthermore, we suggest an agile evaluation process which indicates the order of accessibility guidelines to check. Finally, the proposed evaluation method is put into practice with a case study: accessibility features are evaluated in three widely used players.This research work is supported by the Research Network MAVIR (S2009/TIC-1542 (see www.mavir.net/)), and GEMMA (TSI-020302-2010-141) and SAGAS (TSI-020100-2010-184) research project

A framework for abstraction and virtualization of sensors in mobile context-aware computing

110 p.[EN] The latest mobile devices available nowadays are leading to the development of a new generation of mobile applications that are able to react to context. Context- awareness requires data from the environment, usually collected by means of sensors embedded in mobile devices or connected to them through wireless networks. Developers of mobile applications are faced with several challenges when it comes to the creation of context-aware applications. Sensor and device heterogeneity stand out among these challenges. In order to assist designers, we propose a layered conceptual framework for sensor abstraction and virtualization, called Igerri. Its main objective is to facilitate the development of context-aware applications independently of the specific sensors available in the user environment. To avoid the need to directly manage physical sensors, a layered structure of virtual and abstract sensors is conceived. Two software components, based on the proposed framework, have been designed in order to test Igerris robustness. The first one processes the information from the successive sensor layers and generates high-level context information. The second is responsible for managing network aspects and real time settings. This implementation has been tested using a representative context-aware application in different scenarios. The results obtained show that the implementation, and therefore the conceptual framework, is suitable for dealing with context information and hiding sensor programming.[EU] Gaur egungo gailu mugikor puntakoenek inguruneari erantzuteko gai diren aplikazio mugikorren garapenean oinarritzen dira. Testuingurua nabaritzeko ingurunearen informazioa behar da, zeina gailu mugikorretan txertatutako sentsoreen edo haririk gabeko sareen bitartez biltzen den. Aplikazio mugikorren garatzaileek erronka askori aurre egin behar izaten diete testuingurua kontuan hartzen duten aplikazioak garatzerakoan. Erronka na- gusien artean, sentsoreen eta gailuen heterogeneotasuna izaten dira. Garatzaileei laguntzeko asmoz, Igerri izeneko sentsoreen abstrakzio eta birtualizaziorako marko kontzeptual bat proposatzen dugu. Bere helburu nagusia, testuinguruaren aplikazio hautemangarrien garapena erraztea da, erabiltzailearen ingurunean dauden sentsore espezifikoak edozein direla ere. Sentsore fisikoak zuzenean ma- nipulatu behar izatea saihesteko, sentsore birtual eta abstraktuen egitura bat asmatu da. Igerri-ren sendotasuna egiaztatzeko, proposatutako markoan oinarritutako bi software osagai diseinatu dira. Lehenak, sentsore geruzen informazio geruzak prozesatu eta maila altuko testuinguru informazioa ematen du. Bigarrenak, sare aukerak kudeatu eta sentsoreen konfigurazioa denbora errealean burutzen ditu. Inplementazio hau testuingurua hautemateko gai eta adierazgarria den aplikazio batekin egoera desberdinetan frogatu da. Lortutako emaitzek erakusten dute inplementazioa, eta ondorioz marko kontzeptuala ere, aproposa dela testuinguruaren informazioa erabiltzeko eta sentsoreen programazioa ezkutatzeko.[ES] Los dispositivos móviles disponibles en la actualidad facilitan el desarrollo de una nueva generación de aplicaciones móviles que son capaces de reaccionar al contexto. La computación sensible al contexto requiere datos del entorno que normalmente se obtienen por medio de sensores embebidos en dispositivos móviles o conectados a ellos a través de redes inalámbricas. Los desarrolladores de aplicaciones móviles se enfrentan a varios retos para crear aplicaciones sensibles al contexto. Entre estos retos destaca la necesidad de tratar la heterogeneidad de los sensores y de los dispositivos móviles. Con el fin de ayudar a los desarrolladores, esta tesis propone un marco conceptual para la abstracción multinivel y la virtualización de sensores, llamado Igerri. Su principal objetivo es facilitar el desarrollo de aplicaciones sensibles al contexto independientemente de los sensores específicos que se encuentren en el entorno. Para evitar la necesidad de manipular directamente los sensores físicos, se ha concebido una estructura multinivel de sensores virtuales y abstractos. Se han diseñado dos componentes software basados en el marco propuesto para comprobar la robustez de Igerri. El primero procesa la información de la estructura multinivel de sensores y genera información de contexto de alto nivel. El segundo es responsable de administrar, en tiempo real, las opciones de red y la configuración de los sensores. Esta implementación ha sido probada en diferentes escenarios usando una aplicación representativa y sensible al contexto. Los resultados obtenidos muestran que la implementación, y por tanto el marco conceptual que le da soporte, es adecuada para tratar la información de contexto y ocultar los problemas de programación de los sensores.Borja Gamecho held a PhD scholarship from the Research Staff Training Programme of the Basque Government from 2011 to 2014. This work also has been supported by the Department of Education, Universities and Research of the Basque Government under Grant IT395-10, by the Ministry of Economy and Competitiveness of the Spanish Government and by the European Regional Development Fund (project TIN2014-52665-C2-1)