71,198 research outputs found

    Parallel Multi-Hypothesis Algorithm for Criticality Estimation in Traffic and Collision Avoidance

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    Due to the current developments towards autonomous driving and vehicle active safety, there is an increasing necessity for algorithms that are able to perform complex criticality predictions in real-time. Being able to process multi-object traffic scenarios aids the implementation of a variety of automotive applications such as driver assistance systems for collision prevention and mitigation as well as fall-back systems for autonomous vehicles. We present a fully model-based algorithm with a parallelizable architecture. The proposed algorithm can evaluate the criticality of complex, multi-modal (vehicles and pedestrians) traffic scenarios by simulating millions of trajectory combinations and detecting collisions between objects. The algorithm is able to estimate upcoming criticality at very early stages, demonstrating its potential for vehicle safety-systems and autonomous driving applications. An implementation on an embedded system in a test vehicle proves in a prototypical manner the compatibility of the algorithm with the hardware possibilities of modern cars. For a complex traffic scenario with 11 dynamic objects, more than 86 million pose combinations are evaluated in 21 ms on the GPU of a Drive PX~2

    Investigating design issues of context-aware mobile guides for people with visual impairments

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    While mobile wayfinding systems for visually impaired people offer huge potential, most insufficiently address the differences between visual impairments and contextual environments, and offer very little context-awareness - usability issues of which are vital in supporting independent mobility. Participants experiencing a loss of central vision, loss of peripheral vision, and total vision loss made up three groups. Our multidisciplinary model of context was used to design a user study, which involved asking participants to walk to pre-determined outdoor and indoor landmarks. Significant differences were found between groups relating to information requirements, and the environmental cues encoded and used to orientate and navigate. The study also found differences between indoor and outdoor contexts. It was concluded that what is meaningful to one form of visual impairment is incidental to another. These issues need to be captured and accounted for if wayfinding systems are to be usable

    CGAMES'2009

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    Pricing and Resource Allocation via Game Theory for a Small-Cell Video Caching System

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    Evidence indicates that downloading on-demand videos accounts for a dramatic increase in data traffic over cellular networks. Caching popular videos in the storage of small-cell base stations (SBS), namely, small-cell caching, is an efficient technology for reducing the transmission latency whilst mitigating the redundant transmissions of popular videos over back-haul channels. In this paper, we consider a commercialized small-cell caching system consisting of a network service provider (NSP), several video retailers (VR), and mobile users (MU). The NSP leases its SBSs to the VRs for the purpose of making profits, and the VRs, after storing popular videos in the rented SBSs, can provide faster local video transmissions to the MUs, thereby gaining more profits. We conceive this system within the framework of Stackelberg game by treating the SBSs as a specific type of resources. We first model the MUs and SBSs as two independent Poisson point processes, and develop, via stochastic geometry theory, the probability of the specific event that an MU obtains the video of its choice directly from the memory of an SBS. Then, based on the probability derived, we formulate a Stackelberg game to jointly maximize the average profit of both the NSP and the VRs. Also, we investigate the Stackelberg equilibrium by solving a non-convex optimization problem. With the aid of this game theoretic framework, we shed light on the relationship between four important factors: the optimal pricing of leasing an SBS, the SBSs allocation among the VRs, the storage size of the SBSs, and the popularity distribution of the VRs. Monte-Carlo simulations show that our stochastic geometry-based analytical results closely match the empirical ones. Numerical results are also provided for quantifying the proposed game-theoretic framework by showing its efficiency on pricing and resource allocation.Comment: Accepted to appear in IEEE Journal on Selected Areas in Communications, special issue on Video Distribution over Future Interne

    Towards a multidisciplinary user-centric design framework for context-aware applications

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    The primary aim of this article is to review and merge theories of context within linguistics, computer science, and psychology, to propose a multidisciplinary model of context that would facilitate application developers in developing richer descriptions or scenarios of how a context-aware device may be used in various dynamic mobile settings. More specifically, the aim is to:1. Investigate different viewpoints of context within linguistics, computer science, and psychology, to develop summary condensed models for each discipline. 2. Investigate the impact of contrasting viewpoints on the usability of context-aware applications. 3. Investigate the extent to which single-discipline models can be merged and the benefits and insightfulness of a merged model for designing mobile computers. 4. Investigate the extent to which a proposed multidisciplinary modelcan be applied to specific applications of context-aware computing
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