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Physically attending an event or visiting a venue might not always be practically feasible (e.g., due to travel overhead). This article presents a system that enables users to remotely navigate in and interact with a real-world site using 360° video as primary content format. To showcase the system, a demonstrator has been built that affords virtual exploration of a Belgian museum. The system blends contributions from multiple research disciplines into a holistic solution. Constituting technological building blocks include 360° video, the Augmented Video Viewing (AVV) methodology that allows for Web-driven annotation of video content, a walk-up-and-use mid-air gesture tracking system to enable natural user interaction with the system, Non-Linear Video (NLV) constructs to unlock semi-free visitation of the physical site, and the MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard for adaptive media delivery purposes. The system’s feature list will be enumerated and a high-level discussion of its technological foundations will be provided. The resulting solution is completely HTML5-compliant and therefore portable to a gamut of devices.

Time series of human performances present fluctuations around a mean value. These fluctuations are typically considered as insignificant, and attributable to random noise. Over recent decades, it became clear that temporal fluctuations possess interesting properties, however, one of which the property of fractal 1/f scaling. 1/f scaling indicates that a measured process extends over a wide range of timescales, suggesting an assembly over multiple scales simultaneously. This paper reviews neurological, physiological, and cognitive studies that corroborate the claim that 1/f scaling is most clearly present in healthy, well-coordinated activities. Prominent hypotheses about the origins of 1/f scaling are confronted with these reviewed studies. It is concluded that 1/f scaling in living systems appears to reflect their genuine complex nature, rather than constituting a coincidental side-effect. The consequences of fractal dynamics extending from the small spatial and temporal scales (e.g., neurons) to the larger scales of human behavior and cognition, are vast, and impact the way in which relevant research questions may be approached. Rather than focusing on specialized isolable subsystems, using additive linear methodologies, nonlinear dynamics, more elegantly so, imply a complex systems methodology, thereby exploiting, rather than rejecting, mathematical concepts that enable describing large sets of natural phenomena.

A multitude of application domains benefit from synchronized multimedia content presentation and playback across spatially scattered client stations. Online remote tutoring, telework and teleconferencing, and the non-co-located synchronous browsing through a digital photo album are merely some examples of potential use cases, which are referred to collectively as real-time distributed groupware. This paper presents five concrete schemes that realize media synchronization over the Web. The proposed techniques have been implemented and experimentally validated as part of the synchronous MediaSharing (sMS) service, a framework which grants geographically dispersed users the ability to share and synchronously consume digital pictures and video clips. All five schemes are completely Web-compliant, achieve relatively loose synchronization accuracy, and can be categorized as being non-distributed in the sense that they require centralized coordination. Besides being technically compared, the synchronization solutions are subjected to a high-level assessment in terms of their infrastructural requirements and the thereby associated necessary operational expenditure.

In this overview paper, we present results that were obtained by combining a specific architectural design for Networked Virtual Environments (NVE's) with a generic optimization infrastructure for content streaming. Although the two are - at first sight - targeting unrelated application areas, it turns out that the application knowledge available in the NVE architecture can effectively be used to instruct the adaptation infrastructure to change the way in which data is delivered to the end-user. The end-effect of these optimizations is a fine-grained ability for the combined architecture to deliver the required NVE content to the end-user while optimizing bandwidth usage. Such optimizations are very useful in mobile setups, as the available bandwidth fluctuates significantly over time. The resulting architecture can be deployed in a very dynamic way, including on cloud platforms. An experiment is presented that shows the viability of the ideas discussed in the paper.

The majority of present-day distributed applications demand a certain level of service from the transportation network and impose a number of performance requirements on it. Failure to meet these requirements will typically degrade the efficiency of the application and, more importantly, will likely have a detrimental impact on the experience of the end-user. Over the years, a number of frameworks has therefore been proposed that enable transportation networks to guarantee a certain Quality of Service (QoS) and the positive implications of these frameworks on application performance have been established. Due to the growing attention to human factors however, the focus is increasingly shifting from pure QoS provision towards user experience optimization. Stated differently, in recent years, the goal of guaranteeing a certain level of network performance is evermore being replaced with the aspiration to ensure a high end-user satisfaction or so-called Quality of Experience (QoE). The current generation of telecommunications networks, and the omnipresent Internet in particular, unfortunately lack elaborate and effective constructs for QoE optimization. Mitigating this deficiency forms the subject of this thesis. The overall contribution of this doctoral dissertation is the Network Intelligence Proxy (NIProxy), a network intermediary which has been developed to enable QoE manipulation and optimization in IPv4-based computer networks. As is hinted at by its name, the NIProxy's methodology involves the introduction of "intelligence" in the networking infrastructure. This is achieved by accumulating contextual knowledge regarding the transportation network itself, the distributed application and the end-user (and his terminal). On a finer-grained level, this PhD research contributes to various domains, the first of which being network traffic engineering and application-layer QoS provision. The NIProxy provides two complementary techniques to improve the (multimedia) traffic handling capabilities of the transportation network in which it is deployed. The first technique, network traffic shaping (NTS), enables the in-network coordination and management of the bandwidth consumption of the network traffic that is induced by distributed applications. The second tool, service provision, allows the NIProxy to act as a substrate for the hosting of services that will be applied to the (multimedia) content that fl ows through the network. Both traffic engineering mechanisms are context-aware and context-adaptive since they have unbridled access to the NIProxy's context repository. A second concrete research contribution is situated in the area of network intermediary design and implementation. The service provision platform is designed with extensibility in mind. Thanks to a pluggable implementation, the set of provided services can at run-time be modified and extended. This extensible design for instance enables the NIProxy to cope with heterogeneous conditions in dynamic networking environments without requiring a reboot. Secondly, instead of implementing the NTS and service provision frameworks as isolated entities, an integrated design is adopted so that both traffic engineering techniques are allowed to interface and collaborate. The outcome is a holistic solution in which the composing components supplement each other's strong points and improve their potential through cooperation. Finally, this PhD dissertation presents significant results in the area of context-aware networking and user experience optimization. The ultimate objective of the NIProxy is not to improve the QoS features of the transportation network, but instead to improve the experience of the users which leverage the network to run distributed applications. The viability and the feasibility of the NIProxy as a QoE manipulation and optimization framework is investigated by analyzing the outcomes of numerous experimental evaluations. These studies confirm that the NIProxy is equipped with an elaborate toolset for user experience optimization which enables it to deliver on its objective in a multitude of distributed scenarios, in dynamic environments, under variable network load and amidst heterogeneous mixes of network traffic types. It is also corroborated experimentally that the NIProxy is amenable to cooperation with other QoS provision or QoE optimization solutions and as such can serve as a building block for the construction of larger frameworks. To conclude, it is worth underscoring what this dissertation is not about. The NIProxy is not concerned with (methods for) QoE measurement or the QoE concept per se. This thesis also does not involve the collection of qualitative feedback by means of user studies. Lastly, the NIProxy is not a ready-made solution for QoE optimization; instead, it is a QoE manipulation framework whose actual behavior needs to be attuned to the current context of use. Simply integrating the NIProxy in a transportation network is hence by no means a guarantee for success.

Meetings often suffer from the inability of participants to be physically present in one room. Moreover, with current networking technologies, meeting environments can be distributed over multiple rooms. The goal of the iConnect project is to provide collaboration services while interconnecting both collocated and remote users. We focus on smooth engagement by allowing participants to share arbitrary data through heterogeneous input devices and displays.