Implementation of a User-Centric Context-Aware Playground

Since the introduction of the ubiquitous computing vision by Mark Weiser, we observed quite some research from various R&D projects as well as groups that focused on different aspects in the area of context-awareness. However, there is yet no result which we can easily apply in a real environment. The context-aware service development and deployment process seldom focused on reusability and realistic implementation issues. We believe these issues can be tackled by proposing a complete context-aware system package. In this package both developers and users will be supported. This idea is realised at our department as a context-aware playground. This paper explains the observation on current work and the shortcomings, and proposes how the context-aware playground approach can be a solution

Identity principles in the digital age: a closer view

Identity and its management is now an integral part of web-based services and applications. It is also a live political issue that has captured the interest of organisations, businesses and society generally. As identity management systems assume functionally equivalent roles, their significance for privacy cannot be underestimated. The Centre for Democracy and Technology has recently released a draft version of what it regards as key privacy principles for identity management in the digital age. This paper will provide an overview of the key benchmarks identified by the CDT. The focus of this paper is to explore how best the Data Protection legislation can be said to provide a framework which best maintains a proper balance between 'identity' conscious technology and an individual's expectation of privacy to personal and sensitive data. The central argument will be that increased compliance with the key principles is not only appropriate for a distributed privacy environment but will go some way towards creating a space for various stakeholders to reach consensus applicable to existing and new information communication technologies. The conclusion is that securing compliance with the legislation will prove to be the biggest governance challenge. Standard setting and norms will go some way to ease the need for centralised regulatory oversight

From Buddyspace to CitiTag: Large-scale Symbolic Presence for Community Building and Spontaneous Play

In this paper we discuss the conceptual framework and principles that guide our work in the design of large-scale informal environments for collaborative work, learning and play, aiming to foster social bonds and to provide an exciting testbed for emergent social behaviours. We present three different applications we have developed: Buddyspace, an Instant Messaging environment for community building, BumperCars, an online presence-based multiplayer game and CitiTag, an experimental wireless mixed reality game

In body experiences:Persuasion by doing

In this paper we argue that in the multidisciplinary field related to behavior change support systems using a body-centric approach where participants act rather than discuss and contemplate is a worthwhile technique and should also be investigated more often. Especially now that technology better allows to respond to bodily actions in an appropriate and experiential engaging setting. To this end we will introduce and reflect on two recent case studies we performed: 1) an interactive projection game to trigger better self-management of children with asthma and 2) a Virtual Reality (VR) environment to be integrated in therapy sessions on substance abuse for people with intellectual disabilities (i.e. IQ 50-85 and limited adaptive skills). This resulted in a realistic and controlled environment where individuals with substance use disorder and intellectual disabilities are confronted with substances related to alcohol or cannabis in order to trigger application of strategies for self-control. Both cases included interviews with experts and several user confrontations. These confrontations showed possibilities of including such technologies for persuasive purposes. Furthermore, the responses of the users and experts included where quite positive. This is why we suggest this might be a fruitful direction to look into for other use cases regarding behavior change support systems

Information-centric communication in mobile and wireless networks

Information-centric networking (ICN) is a new communication paradigm that has been proposed to cope with drawbacks of host-based communication protocols, namely scalability and security. In this thesis, we base our work on Named Data Networking (NDN), which is a popular ICN architecture, and investigate NDN in the context of wireless and mobile ad hoc networks. In a first part, we focus on NDN efficiency (and potential improvements) in wireless environments by investigating NDN in wireless one-hop communication, i.e., without any routing protocols. A basic requirement to initiate informationcentric communication is the knowledge of existing and available content names. Therefore, we develop three opportunistic content discovery algorithms and evaluate them in diverse scenarios for different node densities and content distributions. After content names are known, requesters can retrieve content opportunistically from any neighbor node that provides the content. However, in case of short contact times to content sources, content retrieval may be disrupted. Therefore, we develop a requester application that keeps meta information of disrupted content retrievals and enables resume operations when a new content source has been found. Besides message efficiency, we also evaluate power consumption of information-centric broadcast and unicast communication. Based on our findings, we develop two mechanisms to increase efficiency of information-centric wireless one-hop communication. The first approach called Dynamic Unicast (DU) avoids broadcast communication whenever possible since broadcast transmissions result in more duplicate Data transmissions, lower data rates and higher energy consumption on mobile nodes, which are not interested in overheard Data, compared to unicast communication. Hence, DU uses broadcast communication only until a content source has been found and then retrieves content directly via unicast from the same source. The second approach called RC-NDN targets efficiency of wireless broadcast communication by reducing the number of duplicate Data transmissions. In particular, RC-NDN is a Data encoding scheme for content sources that increases diversity in wireless broadcast transmissions such that multiple concurrent requesters can profit from each others’ (overheard) message transmissions. If requesters and content sources are not in one-hop distance to each other, requests need to be forwarded via multi-hop routing. Therefore, in a second part of this thesis, we investigate information-centric wireless multi-hop communication. First, we consider multi-hop broadcast communication in the context of rather static community networks. We introduce the concept of preferred forwarders, which relay Interest messages slightly faster than non-preferred forwarders to reduce redundant duplicate message transmissions. While this approach works well in static networks, the performance may degrade in mobile networks if preferred forwarders may regularly move away. Thus, to enable routing in mobile ad hoc networks, we extend DU for multi-hop communication. Compared to one-hop communication, multi-hop DU requires efficient path update mechanisms (since multi-hop paths may expire quickly) and new forwarding strategies to maintain NDN benefits (request aggregation and caching) such that only a few messages need to be transmitted over the entire end-to-end path even in case of multiple concurrent requesters. To perform quick retransmission in case of collisions or other transmission errors, we implement and evaluate retransmission timers from related work and compare them to CCNTimer, which is a new algorithm that enables shorter content retrieval times in information-centric wireless multi-hop communication. Yet, in case of intermittent connectivity between requesters and content sources, multi-hop routing protocols may not work because they require continuous end-to-end paths. Therefore, we present agent-based content retrieval (ACR) for delay-tolerant networks. In ACR, requester nodes can delegate content retrieval to mobile agent nodes, which move closer to content sources, can retrieve content and return it to requesters. Thus, ACR exploits the mobility of agent nodes to retrieve content from remote locations. To enable delay-tolerant communication via agents, retrieved content needs to be stored persistently such that requesters can verify its authenticity via original publisher signatures. To achieve this, we develop a persistent caching concept that maintains received popular content in repositories and deletes unpopular content if free space is required. Since our persistent caching concept can complement regular short-term caching in the content store, it can also be used for network caching to store popular delay-tolerant content at edge routers (to reduce network traffic and improve network performance) while real-time traffic can still be maintained and served from the content store

Dynamic privacy management in pervasive sensor networks

This paper describes the design and implementation of a dynamic privacy management system aimed at enabling tangible privacy control and feedback in a pervasive sensor network. Our work began with the development of a potentially invasive sensor network (with high resolution video, audio, and motion tracking capabilities) featuring different interactive applications that created incentive for accepting this network as an extension of people’s daily social space. A user study was then conducted to evaluate several privacy management approaches – an active badge system for both online and on-site control, on/off power switches for physically disabling the hardware, and touch screen input control. Results from a user study indicated that an active badge for on-site privacy control is the most preferable method among all provided options. We present a set of results that yield insight into the privacy/benefit tradeoff from various sensing capabilities in pervasive sensor networks and how privacy settings and user behavior relate in these environments.Things That Think Consortiu