Exploring Urban Environments Using Virtual and Augmented Reality

In this paper, we propose the use of specific system architecture, based on mobile device, for navigation in urban environments. The aim of this work is to assess how virtual and augmented reality interface paradigms can provide enhanced location based services using real-time techniques in the context of these two different technologies. The virtual reality interface is based on faithful graphical representation of the localities of interest, coupled with sensory information on the location and orientation of the user, while the augmented reality interface uses computer vision techniques to capture patterns from the real environment and overlay additional way-finding information, aligned with real imagery, in real-time. The knowledge obtained from the evaluation of the virtual reality navigational experience has been used to inform the design of the augmented reality interface. Initial results of the user testing of the experimental augmented reality system for navigation are presented.

The MIRELA framework: modeling and analyzing mixed reality applications using timed automata

Mixed Reality (MR) aims to link virtual entities with the real world and has many applications such as military and medical domains [JBL+00, NFB07]. In many MR systems and more precisely in augmented scenes, one needs the application to render the virtual part accurately at the right time. To achieve this, such systems acquire data related to the real world from a set of sensors before rendering virtual entities. A suitable system architecture should minimize the delays to keep the overall system delay (also called end-to-end latency) within the requirements for real-time performance. In this context, we propose a compositional modeling framework for MR software architectures in order to specify, simulate and validate formally the time constraints of such systems. Our approach is first based on a functional decomposition of such systems into generic components. The obtained elements as well as their typical interactions give rise to generic representations in terms of timed automata. A whole system is then obtained as a composition of such defined components. To write specifications, a textual language named MIRELA (MIxed REality LAnguage) is proposed along with the corresponding compilation tools. The generated output contains timed automata in UPPAAL format for simulation and verification of time constraints. These automata may also be used to generate source code skeletons for an implementation on a MR platform. The approach is illustrated first on a small example. A realistic case study is also developed. It is modeled by several timed automata synchronizing through channels and including a large number of time constraints. Both systems have been simulated in UPPAAL and checked against the required behavioral properties.

Facebook’s Real Name Policy: Bye-Bye, Max Mustermann?

Facebook requires all members to use their real names and email addresses when joining the social network. Not only does the policy seem to be difficult to enforce (as the prevalence of accounts with people’s pets or fake names suggests), but it may also interfere with European (and, in particular, German) data protection laws. A German Data Protection Commissioner recently took action and ordered that Facebook permit pseudonymous accounts as its current anti-pseudonymous policy violates § 13 VI of the German Telemedia Act. This provision requires telemedia providers to allow for an anonymous or pseudonymous use of services insofar as this is reasonable and technically feasible. Irrespective of whether the pseudonymous use of Facebook is reasonable, the case can be narrowed down to one single question: Does German data protection law apply to Facebook? In that respect, this paper analyses the current Facebook dispute, in particular in relation to who controls the processing of personal data of Facebook users in Germany. It also briefly discusses whether a real name policy really presents a fix for anti-normative and anti-social behaviour on the Internet.