The Price of Fog: a Data-Driven Study on Caching Architectures in Vehicular Networks

Vehicular users are expected to consume large amounts of data, for both entertainment and navigation purposes. This will put a strain on cellular networks, which will be able to cope with such a load only if proper caching is in place, this in turn begs the question of which caching architecture is the best-suited to deal with vehicular content consumption. In this paper, we leverage a large-scale, crowd-collected trace to (i) characterize the vehicular traffic demand, in terms of overall magnitude and content breakup, (ii) assess how different caching approaches perform against such a real-world load, (iii) study the effect of recommendation systems and local contents. We define a price-of-fog metric, expressing the additional caching capacity to deploy when moving from traditional, centralized caching architectures to a "fog computing" approach, where caches are closer to the network edge. We find that for location-specific contents, such as the ones that vehicular users are most likely to request, such a price almost disappears. Vehicular networks thus make a strong case for the adoption of mobile-edge caching, as we are able to reap the benefit thereof -- including a reduction in the distance traveled by data, within the core network -- with little or no of the associated disadvantages.Comment: ACM IoV-VoI 2016 MobiHoc Workshop, The 17th ACM International Symposium on Mobile Ad Hoc Networking and Computing: MobiHoc 2016-IoV-VoI Workshop, Paderborn, German

CUI@CSCW: Collaborating through Conversational User Interfaces

This virtual workshop seeks to bring together the burgeoning communities centred on the design, development, application and study of so-called Conversational User Interfaces (CUIs). CUIs are used in myriad contexts, from online support chatbots through to entertainment devices in the home. In this workshop, we will examine the challenges involved in transforming CUIs into everyday computing devices capable of supporting collaborative activities across space and time. Additionally, this workshop seeks to establish a cohesive CUI community and research agenda within CSCW. We will examine the roles in which CSCW research can contribute insights into understanding how CUIs are or can be used in a variety of settings, from public to private, and how they can be brought into a potentially unlimited number of tasks. This proposed workshop will bring together researchers from academia and practitioners from industry to survey the state-of-the-art in terms of CUI design, use, and understanding, and will map new areas for work including addressing the technical, social, and ethical challenges that lay ahead. By bringing together existing researchers and new ideas in this space, we intend to foster a strong community and enable potential future collaborations

Strategies and challenges to facilitate situated learning in virtual worlds post-Second Life

Virtual worlds can establish a stimulating environment to support a situated learning approach in which students simulate a task within a safe environment. While in previous years Second Life played a major role in providing such a virtual environment, there are now more and more alternative—often OpenSim-based—solutions deployed within the educational community. By drawing parallels to social networks, we discuss two aspects: how to link individually hosted virtual worlds together in order to implement context for immersion and how to identify and avoid “fake” avatars so people behind these avatars can be held accountable for their actions

Integrating perceptual, device and location characteristics for wireless multimedia transmission

In this paper,we describe an investigation exploring user experiences of accessing streamed multimedia content, when that content is tailored according to perceptual, device and location characteristics. To this end, we have created pre-defined transmission profiles and stream perceptually tailored multimedia content to three different locations, each characterised by different infotainment requirements. In the light of our results, we propose that multimedia transmission to mobile and wireless devices should be made based on pre-defined profiles, which contains a combination of static (perceptual, device type, CPU speed, and display specifications) and dynamic information (streamed content type location of the device/user, context of the device/user). The evaluation of such a system showed that the users and service providers can gain from such an approach considerably, as user perceptions of quality were not detrimentally affected by QoS degradations. Consequently, service providers can utilise this information to effectively manage local network traffic and bandwidth

Aspects of opening play

In this paper, we study opening play in games. We show experiments using minimax and a semi-random player. In the experiment, we let each semi-random player use an opening-book, created by different player. Results show evidence for the following statements. The game length increases. Expert player against an intermediate player should not use an opening book in a tournament match. Some opening books are good for novices and some opening books are bad for novices. The game outcome will approach the outcome of the game when the opening book was created, and if a grandmaster creates the opening book then the outcome will be the same as the grandmaster’s