A Scalable Solution For Interactive Video Streaming

This dissertation presents an overall solution for interactive Near Video On Demand (NVOD) systems, where limited server and network resources prevent the system from servicing all customers’ requests. The interactive nature of recent workloads complicates matters further. Interactive requests require additional resources to be handled. This dissertation analyzes the system performance under a realistic workload using different stream merging techniques and scheduling policies. It considers a wide range of system parameters and studies their impact on the waiting and blocking metrics. In order to improve waiting customers experience, we propose a new scheduling policy for waiting customers that is fairer and delivers a descent performance. Blocking is a major issue in interactive NVOD systems and we propose a few techniques to minimize it. In particular, we study the maximum Interactive Stream (I-Stream) length (Threshold) that should be allowed in order to prevent a few requests from using the expensive I-Streams for a prolonged period of time, which starves other requests from a chance of using this valuable resource. Using a reasonable I-Stream threshold proves very effective in improving blocking metrics. Moreover, we introduce an I-Stream provisioning policy to dynamically shift resources based on the system requirements at the time. The proposed policy proves to be highly effective in improving the overall system performance. To account for both average waiting time and average blocking time, we introduce a new metric (Aggregate Delay) . We study the client-side cache management policy. We utilize the customer’s cache to service most interactive requests, which reduces the load on the server. We propose three purging algorithms to clear data when the cache gets full. Purge Oldest removes the oldest data in the cache, whereas Purge Furthest clears the furthest data from the client’s playback point. In contrast, Adaptive Purge tries to avoid purging any data that includes the customer’s playback point or the playback point of any stream that is being listened to by the client. Additionally, we study the impact of the purge block, which is the least amount of data to be cleared, on the system performance. Finally, we study the effect of bookmarking on the system performance. A video segment that is searched and watched repeatedly is called a hotspot and is pointed to by a bookmark. We introduce three enhancements to effectively support bookmarking. Specifically, we propose a new purging algorithm to avoid purging hotspot data if it is already cached. On top of that, we fetch hotspot data for customers not listening to any stream. Furthermore, we reserve multicast channels to fetch hotspot data

AXMEDIS 2007 Conference Proceedings

The AXMEDIS International Conference series has been established since 2005 and is focused on the research, developments and applications in the cross-media domain, exploring innovative technologies to meet the challenges of the sector. AXMEDIS2007 deals with all subjects and topics related to cross-media and digital-media content production, processing, management, standards, representation, sharing, interoperability, protection and rights management. It addresses the latest developments and future trends of the technologies and their applications, their impact and exploitation within academic, business and industrial communities

Educational use cases from a shared exploration of e-books and iPads

E-books and e-book readers are becoming increasingly widely available, particularly for the general reader, and there have been many studies on their adoption. However, less is known about their use for educational and academic purposes. We report here on work carried out on e-books and e-book applications using iPads by academic and teaching staff. After considering pedagogical issues and reporting survey results, we identify a spiral of six key use case areas for e-books. This spiral of use cases moves from basic e-book use, through situational reading, e-books and learning, using multiple learning resources, collaborative/group learning, to e-book production. We discuss each of these use case areas and provide guidelines that will be of interest to practitioners and researchers alike

Deliverable D9.3 Final Project Report

This document comprises the final report of LinkedTV. It includes a publishable summary, a plan for use and dissemination of foreground and a report covering the wider societal implications of the project in the form of a questionnaire

Artistic research into distraction, agency, and the internet

This practical study is concerned with flows of attention and distraction that are associated with experiences of the internet. Taking the term ‘internet’ to stand for a range of networked social, media-consumption, and data practices carried out on devices such as smartphones, this study sets out to explore how distraction might arise, how it might be conceptualised, and the potential consequences for agency of the conditions of its emergence. The study is led by the production and analysis of artworks, using practical approaches that engage critically with aspects of the experience of the internet. This thesis begins by exploring conceptions of the ‘attention economy’ articulated by Goldhaber (1997), Beller (2006), and Citton (2017), developing an understanding that counters mainstream deterministic positions regarding the impact of digital technologies on the capacity for focused attention. Distraction is considered as an experience that may be sought out by individuals but can be captured and extended by third parties such as social media platforms. The importance of the data generated by habitual or compulsive engagement with internet-enabled devices and services (Zuboff, 2015) is considered against a backdrop of quantification and managerialism that extends beyond experiences of the internet. The study reviews existing artworks made in response to these concerns, focusing on expressions of the ‘attention economy’ prevalent in ‘postinternet’ art. Works by Vierkant (2010), Roth (2015) and others that interrogate infrastructure, data-gathering, or networked methods of distribution are identified as relevant, and a position is developed from which the consequences of metricised display platforms for an artistic ‘attention economy’ can be explored. Prototype artworks made during the study are appraised using an artistic research methodology that foregrounds the role of the researcher as both producer and reader of the artwork. Works that actively create distraction, that gather and visualise data, and that emphasise calm self-interrogation, are discussed and evaluated. The practical aspects of the research contribute to knowledge by extending understanding of the spatial, infrastructural, and algorithmic dimensions of the relationship between distraction and agency

Semantic Annotation of Digital Objects by Multiagent Computing: Applications in Digital Heritage

Heritage organisations around the world are participating in broad scale digitisation projects, where traditional forms of heritage materials are being transcribed into digital representations in order to assist with their long-term preservation, facilitate cataloguing, and increase their accessibility to researchers and the general public. These digital formats open up a new world of opportunities for applying computational information retrieval techniques to heritage collections, making it easier than ever before to explore and document these materials. One of the key benefits of being able to easily share digital heritage collections is the strengthening and support of community memory, where members of a community contribute their perceptions and recollections of historical and cultural events so that this knowledge is not forgotten and lost over time. With the ever-growing popularity of digitally-native media and the high level of computer literacy in modern society, this is set to become a critical area for preservation in the immediate future