Securing Passive Objects in Mobile Ad-Hoc Peer-to-Peer Networks

Security and privacy in mobile ad-hoc peer-to-peer environments are hard to attain, especially when working with passive objects (without own processing power, e.g. RFID tags). This paper introduces a method for integrating such objects into a peer-to-peer environment without infrastructure components while providing a high level of privacy and security for peers interacting with objects. The integration is done by associating public keys to passive objects, which can be used by peers to validate proxies (peers additionally acting on behalf of objects). To overcome the problem of limited storage capacity on small embedded objects, ECC keys are used.     

Embedded interactive systems: back to the real world

The maturing of reliable wireless communication technologies for local and personal area networks, the broad availability of miniaturized sensor and actuator hardware technologies, and the tremendous growth of global networks like the Internet over the past years have accelerated the emergence of “networked embedded systems”. So called “smart appliances”, i.e. ad-hoc networked, mobile, autonomous, special purpose computing appliances have appeared, usually interacting with their environment implicitly via a variety of sensors on the input side, and actuators on the output side. With the embedding of invisible technology into everyday things and architectural spaces, things and spaces also become the interface to “hidden” or “invisible” computational services. Embedded interactive systems allow to mediate between the physical and digital (or virtual) world via natural interaction — away from the desktop displays and keyboards. The embedding of sophisticated sensor, actuator and wireless communication technologies, together with novel interface concepts for situated interaction (tangible interfaces, attentive interfaces) give rise for bringing the interaction with computers “back to the real world”.     

Traffic flow harmonization in expressway merging

Steering a vehicle is a task increasingly challenging the driver in terms of mental resources. Reasons for this include the increasing volume of road traffic and a rising quantity of road signs, traffic lights, and other distractions at the roadside (such as billboards), to name a few. The application of Advanced Driver Assistance Systems, in particular if taking advantage of Ambient Intelligence (AmI) technology, can help to increase the perceptivity of a driver, leading as a direct consequence to more relaxed mental stress of the same. One situation where we see potential in the application of such a system are merging areas on the expressway where two or more varying traffic streams converge into a single one. In order to reduce cognitive liabilities (in this work expressed as panic or anger), drivers are exposed to while merging, we have developed two behavioral rules. The first (“increased range of perception”) enables drivers to change early upstream into a spare lane, allowing the merging traffic to join into mainline traffic at reduced conflicts, the second (“inter-car distance management” in the broader area of merging) provide drivers with recommendations of when and how to change lanes at the best. From a technical point of view, the “VibraSeat” a in-house developed car seat with integrated tactile actuators, is used for delivering information about perception range and inter-car distances to the driver in a way that does not stress his/her mental capabilities. To figure out possible improvements in its application in real traffic and at a meaningful scale, cellular automaton–based simulation of a specific section of Madrid expressway M30 was performed. Results from the data-driven simulation experiments on the true to scale model indicate that AmI technology has the potential to increase road throughput or average driving speed and furthermore to decrease the panic of drivers while merging into an upper (the main) lane.     

Wearable Displays for Everyone!

Spectacles is a hardware/software platform developed from off-the-shelf components and ready for market. It includes local computation and communication facilities, an integrated power supply, and modular system building blocks such as sensors, voice-to-text and text-to-speech components, localization and positioning units, and microdisplay units. Its see-through display components are integrated into eyeglass frames.     

Adaptive time warp simulation of timed Petri nets

Time warp (TW), although generally accepted as a potentially effective parallel and distributed simulation mechanism for timed Petri nets, can reveal deficiencies in certain model domains. Particularly, the unlimited optimism underlying TW can lead to excessive aggressiveness in memory consumption due to saving state histories, and waste of CPU cycles due to over-optimistically progressing simulations that eventually have to be “rolled back”. Furthermore, in TW simulations executing in distributed memory environments, the communication overhead induced by the roll-back mechanism can cause pathological overall simulation performance. In this work, an adaptive optimism control mechanism for TW is developed to overcome these shortcomings. By monitoring and statistically analyzing the arrival processes of synchronization messages, TW simulation progress is probabilistically throttled based on the forecasted time stamp of forthcoming messages. Two classes of arrival process characterizations are studied, reflecting that a natural trade-off exists among the computational and space complexity, and the respective prediction accuracy: While forecasts based on metrics of central tendency are computationally cheap but yield inadequate predictions for correlated arrivals (thus negatively affecting performance), time series based forecast methods give higher prediction accuracy, but at higher computational cost     

A framework for utilizing qualitative spatial relations between networked embedded systems

With more and more everyday artifacts being equipped with networked embedded systems technology, their spatial situation or context–such as where they are located or whether two of them are near or far apart from each other–is becoming increasingly relevant. The emerging availability of sensor technologies for measuring properties of the physical space enables them to become aware of their spatial context and adapt to changes accordingly, which in turn contributes to the implementation of systems that operate autonomously in the background and interact with humans in a more unobtrusive way. In this article, we specifically address the use of spatial relations between technology-rich artifacts as well as their changes over time. A key aspect is the abstraction of spatial contexts in order to separate details which are not relevant for a certain application, and thereby save computational resources or provide spatial information in a way that is closer to human concepts of space. In this regard, our focus is on qualitatively represented spatial relations, which are used as the basic building blocks for the development of spatially aware applications. A novel software framework is presented for this purpose and evaluated with respect to its performance as well as its adequacy for building real-world applications.     

Augmented reality navigation systems

The augmented reality (AR) research community has been developing a manifold of ideas and concepts to improve the depiction of virtual objects in a real scene. In contrast, current AR applications require the use of unwieldy equipment which discourages their use. In order to essentially ease the perception of digital information and to naturally interact with the pervasive computing landscape, the required AR equipment has to be seamlessly integrated into the user’s natural environment. Considering this basic principle, this paper proposes the car as an AR apparatus and presents an innovative visualization paradigm for navigation systems that is anticipated to enhance user interaction.