Liquid stream processing on the web: a JavaScript framework

The Web is rapidly becoming a mature platform to host distributed applications. Pervasive computing application running on the Web are now common in the era of the Web of Things, which has made it increasingly simple to integrate sensors and microcontrollers in our everyday life. Such devices are of great in- terest to Makers with basic Web development skills. With them, Makers are able to build small smart stream processing applications with sensors and actuators without spending a fortune and without knowing much about the technologies they use. Thanks to ongoing Web technology trends enabling real-time peer-to- peer communication between Web-enabled devices, Web browsers and server- side JavaScript runtimes, developers are able to implement pervasive Web ap- plications using a single programming language. These can take advantage of direct and continuous communication channels going beyond what was possible in the early stages of the Web to push data in real-time. Despite these recent advances, building stream processing applications on the Web of Things remains a challenging task. On the one hand, Web-enabled devices of different nature still have to communicate with different protocols. On the other hand, dealing with a dynamic, heterogeneous, and volatile environment like the Web requires developers to face issues like disconnections, unpredictable workload fluctuations, and device overload. To help developers deal with such issues, in this dissertation we present the Web Liquid Streams (WLS) framework, a novel streaming framework for JavaScript. Developers implement streaming operators written in JavaScript and may interactively and dynamically define a streaming topology. The framework takes care of deploying the user-defined operators on the available devices and connecting them using the appropriate data channel, removing the burden of dealing with different deployment environments from the developers. Changes in the semantic of the application and in its execution environment may be ap- plied at runtime without stopping the stream flow. Like a liquid adapts its shape to the one of its container, the Web Liquid Streams framework makes streaming topologies flow across multiple heterogeneous devices, enabling dynamic operator migration without disrupting the data flow. By constantly monitoring the execution of the topology with a hierarchical controller infrastructure, WLS takes care of parallelising the operator execution across multiple devices in case of bottlenecks and of recovering the execution of the streaming topology in case one or more devices disconnect, by restarting lost operators on other available devices

MediaSync: Handbook on Multimedia Synchronization

This book provides an approachable overview of the most recent advances in the fascinating field of media synchronization (mediasync), gathering contributions from the most representative and influential experts. Understanding the challenges of this field in the current multi-sensory, multi-device, and multi-protocol world is not an easy task. The book revisits the foundations of mediasync, including theoretical frameworks and models, highlights ongoing research efforts, like hybrid broadband broadcast (HBB) delivery and users' perception modeling (i.e., Quality of Experience or QoE), and paves the way for the future (e.g., towards the deployment of multi-sensory and ultra-realistic experiences). Although many advances around mediasync have been devised and deployed, this area of research is getting renewed attention to overcome remaining challenges in the next-generation (heterogeneous and ubiquitous) media ecosystem. Given the significant advances in this research area, its current relevance and the multiple disciplines it involves, the availability of a reference book on mediasync becomes necessary. This book fills the gap in this context. In particular, it addresses key aspects and reviews the most relevant contributions within the mediasync research space, from different perspectives. Mediasync: Handbook on Multimedia Synchronization is the perfect companion for scholars and practitioners that want to acquire strong knowledge about this research area, and also approach the challenges behind ensuring the best mediated experiences, by providing the adequate synchronization between the media elements that constitute these experiences

The production of digital public spaces

Digital media are noticeably changing the qualities of urban public spaces, which can no longer be considered a purely physical construct. Yet, the extent to which contemporary digital media can be used to promote other forms of spatial agency remains a critical issue. Whereas the impact of technology from a macro perspective offers a globalizing and homogenizing image, its role in the production of space at a local scale is less clear (Kirsch 1995). The aim of this study is to argue for digital public spaces as a concrete programme to support the articulation of a third notion of public space that emerges at the interface of physical–digital hybrid spaces (Stikker 2013). The project for digital public spaces is posed as one that pursues enabling citizens’ rights to participation and appropriation (Purcell 2002) of physical–digital hybrid spaces. It is argued that while physical and digital spaces do not stand in opposition, their operational models do not fit seamlessly either. Therefore, the research is particularly concerned with how to design for the conditions that allow a dialogical relation between physical and digital features of space, and enable citizens to actively participate in the production of physical–digital hybrid spaces, and for which a dialectical mode of analysis is required. Following a cumulative narrative, the study explores different characterizations of digital public spaces, which have been articulated through design-led action research projects conducted in collaboration with academia, creative industries, citizens and public authorities. The study accomplishes a novel application of the unitary theory of space proposed by the Marxist French philosopher and sociologist, Henri Lefebvre (1992), which is revisited to develop a novel framework to reveal the social production of physical–digital hybrid spaces. The framework is developed through practice, and extensively applied throughout the thesis illustrating three distinctive dominating perspectives of physical–digital hybrid spaces: substitution, co-evolution and recombination (Graham 1998). The framework has proved to be a flexible and insightful method of analysis that: enables approaching the social production of physical and digital spaces individually and in relation to one another; to understand how different spatial configurations allow for participation and appropriation; and in turn, to re-contextualize the right to the city (Lefebvre 1996) in digital public spaces

Mashup Ecosystems: Integrating Web Resources on Desktop and Mobile Devices

The Web is increasingly used as an application platform, and recent development of it has introduced software ecosystems where different actors collaborate. This collaboration is international from day one, and it evolves and grows rapidly. In web ecosystems applications are provided as services, and interdependencies between ecosystem parts can vary from very strong and obvious to loose and recondite. Mashups -- web application hybrids that combine resources from different services into an integrated system that has increased value from user perspective -- are exploiting services of the Web and creating ecosystems where end-users, mashup authors, and service providers collaborate. The term "resources" is used here in a broad sense, and it can refer to user's local data, infinite content of the Web, and even executable code. This dissertation presents mashups as a new breed of web applications that are intended for parsing the web content into an easily accessed form on both regular desktop computers as well as on mobile devices. Constantly evolving web technologies and new web services open up unforeseen possibilities for mashup development. However, developing mashups with current methods and tools for existing deployment environments is challenging. First, the Web as an application platform faces numerous shortcomings, second, web application development practices in general are still immature, and third, development of mashups has additional requirements that need to be addressed. In addition, mobility sets even more challenges for mashup authoring. This dissertation describes and addresses numerous issues regarding mashup ecosystems and client-side mashup development. To achieve this, we have implemented technical research artifacts including mashup ecosystems and different kinds of mashup compositions. The artifacts are developed with numerous runtime environments and tools and targeted at different end-user platforms. This has allowed us to evaluate methods, tools, and practises used during the implementation. As result, this dissertation identifies the fundamental challenges of mashup ecosystems and describes how service providers and mashup ecosystem authors can address these challenges in practice. In addition, example implementation of a specialized multimedia mashup ecosystem for mobile devices is described. To address mashup development issues, this dissertation introduces practical guidelines and a reference architecture that can be applied when mashups are created with traditional web development tools. Moreover, environments that can be used on mobile devices to create mashups that have access to both web and local resources are introduced. Finally, a novel approach to web software development -- creating software as a mashup -- is introduced, and a realization of such concept is described

Un enfoque orientado a usuarios finales para el desarrollo de aplicaciones de aumentación web móvil

La información existente en la Web podría utilizarse para resolver una amplia gama de problemas de diferentes dominios, pero dicha información no siempre se encuentra reunida en un mismo contexto y resulta difícil encontrar una manera de relacionarla para satisfacer necesidades que, a veces, son requeridas por una minoría de usuarios. Los sitios Web son diseñados para un único usuario, sino más bien enfocados en un conjunto de ellos con características similares y para llevar a cabo tareas específicas, que pueden diferir de las que un usuario particular necesita. Aquí es donde la Aumentación Web se presenta como un medio para lograr la adaptación de los recursos Web existentes de acuerdo con los requisitos del usuario, tanto en contenido como en comportamiento, estructura y/o forma. Por su parte, la tendencia hacia el uso activo de los dispositivos móviles ha hecho posible que la Web sea concebida no sólo como un espacio de información, sino también como una plataforma omnipresente donde sus usuarios realizan todo tipo de tareas. Sin embargo, pese a su uso, muchas aplicaciones Web aún no tienen una contraparte móvil que haga uso de sus características, e incluso algunas ni siquiera responden a un diseño Web responsive. La información del contexto permite mejorar la experiencia del usuario. Por ejemplo, permite filtrar y solo presentar aquella información que coincide con la posición del usuario, la presión sonora en el ambiente o un rango horario determinado. La Aumentación Web Móvil puede ayudar a agregar incorporar características, y mediante técnicas de Desarrollo por Usuarios Finales es posible convertir a las personas que poseen tal necesidad, en los autores de su propia solución de aumentación. Aunque algunos enfoques existen para aumentar aplicaciones Web, incluso con características móviles, los mismos son dirigidos y limitados a personas con –al menos– conocimiento en programación. También existe un gran número de herramientas de autoría que permiten la creación de aplicaciones móviles desde entornos de escritorio, nativos o móviles, pero ninguna de ellas genera aplicaciones Web puras; ejecutables en un navegador Web móvil convencional y sin depender de algún componente nativo para su ejecución. En esta obra se presenta un nuevo enfoque para permitir que los usuarios finales mejoren sus sitios Web preferidos con características móviles. El proceso de autoría es asistido por formularios, y un paso final que combina live programming y composición mediante widgets visuales. El enfoque fue evaluado mediante el uso de una herramienta de soporte, por 21 usuarios finales, y sus resultados demuestran que el enfoque es viable y prometedor, puesto que los usuarios finales fueron capaces de completar, en promedio, el 84% de los requerimientos del experimento.Tesis digirida por los Dres. Gustavo Rossi y Sergio Firmenich.Facultad de Informátic

Thriving in a colder and more challenging climate

Hawkridge, D., Ng, K., & Verjans, S. (Eds.) (2011). Thriving in a colder and more challenging climate. The 18th annual conference of the Association for Learning Technology (ALT-C 2011). September, 6-8, 2011, University of Leeds, England, UK. URI:http://repository.alt.ac.uk/2159Here are the proceedings of the 2011 ALT Conference ‘‘Thriving in a colder and more challenging climate’’. Proceedings papers report on a piece of research, possibly in its early stages, or they can be ‘‘thoughtpieces’’ which state a point of view or summarise an area of work, perhaps giving new insights. The conference has six themes: . Research and rigour: creating, marshalling and making effective use of evidence . Making things happen: systematic design, planning and implementation . Broad tents and strange bedfellows: collaborating, scavenging and sharing to increase value . At the sharp end: enabling organisations and their managers to solve business, pedagogic and technical challenges . Teachers of the future: understanding and influencing the future role and practices of teachers . Preparing for a thaw: looking ahead to a time beyond the disruptive discontinuities of the next few years. Interestingly, there were very few proposals for the conference as a whole against the sixth theme: and no proceedings papers. Perhaps the thaw is still perceived as being too far away to warrant any preparation yet!Association for learning technolog