390 research outputs found

    Three applications for mobile epidemic algorithms

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    This paper presents a framework for the pervasive sharing of data using wireless networks. 'FarCry' uses the mobility of users to carry files between separated networks. Through a mix of ad-hoc and infrastructure-based wireless networking, files are transferred between users without their direct involvement. As users move to different locations, files are then transmitted on to other users, spreading and sharing information. We examine three applications of this framework. Each of these exploits the physically proximate nature of social gatherings. As people group together in, for example, business meetings and cafés, this can be taken as an indication of similar interests, e.g. in the same presentation or in a type of music. MediaNet affords sharing of media files between strangers or friends, MeetingNet shares business documents in meetings, and NewsNet shares RSS feeds between mobile users. NewsNet also develops the use of pre-emptive caching: collecting information from others not for oneself, but for the predicted later sharing with others. We offer observations on developing this system for a mobile, multi-user, multi-device environment

    Supporting ethnographic studies of ubiquitous computing in the wild

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    Ethnography has become a staple feature of IT research over the last twenty years, shaping our understanding of the social character of computing systems and informing their design in a wide variety of settings. The emergence of ubiquitous computing raises new challenges for ethnography however, distributing interaction across a burgeoning array of small, mobile devices and online environments which exploit invisible sensing systems. Understanding interaction requires ethnographers to reconcile interactions that are, for example, distributed across devices on the street with online interactions in order to assemble coherent understandings of the social character and purchase of ubiquitous computing systems. We draw upon four recent studies to show how ethnographers are replaying system recordings of interaction alongside existing resources such as video recordings to do this and identify key challenges that need to be met to support ethnographic study of ubiquitous computing in the wild

    Abstract machines: overlaying virtual worlds on physical rides

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    Overlaying virtual worlds onto existing physical rides and altering the sensations of motion can deliver new experiences of thrill, but designing how motion is mapped between physical ride and virtual world is challenging. In this paper, we present the notion of an abstract machine, a new form of intermediate design knowledge that communicates motion mappings at the level of metaphor, mechanism and implementation. Following a performance-led, in-the-wild approach we report lessons from creating and touring VR Playground, a ride that overlays four distinct abstract machines and virtual worlds on a playground swing. We compare the artist's rationale with riders' reported experiences and analysis of their physical behaviours to reveal the distinct thrills of each abstract machine. Finally, we discuss how to make and use abstract machines in terms of heuristics for designing motion mappings, principles for virtual world design and communicating experiences to riders

    Picking pockets on the lawn: the development of tactics and strategies in a mobile game

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    This paper presents Treasure, an outdoor mobile multiplayer game inspired by Weiser’s notion of seams, gaps and breaks in different media. Playing Treasure involves movement in and out of a wi-fi network, using PDAs to pick up virtual ’coins’ that may be scattered outside network coverage. Coins have to be uploaded to a server to gain game points, and players can collaborate with teammates to double the points given for an upload. Players can also steal coins from opponents. As they move around, players’ PDAs sample network signal strength and update coverage maps. Reporting on a study of players taking part in multiple games, we discuss how their tactics and strategies developed as their experience grew with successive games. We suggest that meaningful play arises in just this way, and that repeated play is vital when evaluating such games

    Archives of thrill: the V-Armchair experience

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    Technology for older people is typically concerned either with health care or accessibility of existing systems. In this paper we take a more ‘entertainment-oriented’ approach to developing experiences aimed at older users. We describe here the design, development and a user study of the V-Armchair, a virtual reality and motion platform based roller coaster experience. The V-Armchair constitutes a blueprint for the digital archiving of physical ride experiences through the simultaneous capture of 360 video, sound and motion. It gives access to thrill experiences to those who may not be able to go on real thrill rides, such as older riders, and it can be considered as a class of technology that could help to support ‘active aging’ as defined by the World Health Organisation. We discuss strategies for capturing and then ‘toning down’ motion experiences to make them accessible for older users. We present a study which explores the user experience of the V-Armchair with an older group (median age 63) using a DK2 headset, and a younger group (median age 25) using a CV1 headset, via thematic analysis of semi-structured interviews and a modified version of the Game Experience Questionnaire, and discuss emergent themes such as the role of the presenter, reminiscence, presence and immersion

    The Nottingham Multi-Modal Corpus: a demonstration

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    This software demonstration overviews the developments made during the 3-year NCeSS funded Understanding New Forms of the Digital Record for e-Social Science project (DReSS) that was based at the University of Nottingham. The demo highlights the outcomes of a specific ‘driver project’ hosted by DReSS, which sought to combine the knowledge of linguists and the expertise of computer scientists in the construction of the multi-modal (MM hereafter) corpus software: the Digital Replay System (DRS). DRS presents ‘data’ in three different modes, as spoken (audio), video and textual records of real-life interactions, accurately aligning within a functional, searchable corpus setting (known as the Nottingham Multi-Modal Corpus: NMMC herein). The DRS environment therefore allows for the exploration of the lexical, prosodic and gestural features of conversation and how they interact in everyday speech. Further to this, the demonstration introduces a computer vision based gesture recognition system which has been constructed to allow for the detection and preliminary codification of gesture sequences. This gesture tracking system can be imported into DRS to enable an automated approach to the analysis of MM datasets

    Universal neural field computation

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    Turing machines and G\"odel numbers are important pillars of the theory of computation. Thus, any computational architecture needs to show how it could relate to Turing machines and how stable implementations of Turing computation are possible. In this chapter, we implement universal Turing computation in a neural field environment. To this end, we employ the canonical symbologram representation of a Turing machine obtained from a G\"odel encoding of its symbolic repertoire and generalized shifts. The resulting nonlinear dynamical automaton (NDA) is a piecewise affine-linear map acting on the unit square that is partitioned into rectangular domains. Instead of looking at point dynamics in phase space, we then consider functional dynamics of probability distributions functions (p.d.f.s) over phase space. This is generally described by a Frobenius-Perron integral transformation that can be regarded as a neural field equation over the unit square as feature space of a dynamic field theory (DFT). Solving the Frobenius-Perron equation yields that uniform p.d.f.s with rectangular support are mapped onto uniform p.d.f.s with rectangular support, again. We call the resulting representation \emph{dynamic field automaton}.Comment: 21 pages; 6 figures. arXiv admin note: text overlap with arXiv:1204.546

    Constraints on the Ultra High Energy Photon flux using inclined showers from the Haverah Park array

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    We describe a method to analyse inclined air showers produced by ultra high energy cosmic rays using an analytical description of the muon densities. We report the results obtained using data from inclined events (60^{\circ}<\theta<80^{\circ}) recorded by the Haverah Park shower detector for energies above 10^19 eV. Using mass independent knowledge of the UHECR spectrum obtained from vertical air shower measurements and comparing the expected horizontal shower rate to the reported measurements we show that above 10^19 eV less than 48 % of the primary cosmic rays can be photons at the 95 % confidence level and above 4 X 10^19 eV less than 50 % of the cosmic rays can be photonic at the same confidence level. These limits place important constraints on some models of the origin of ultra high-energy cosmic rays.Comment: 45 pages, 25 figure

    Molecular detection of Strongyloides sp. in Australian thoroughbred foals

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    Background Strongyloides westeri is found in the small intestine of young horses, mainly in foals up to about 16 weeks of age. The main source of infection for foals is through transmammary transmission, and foals can develop acute diarrhoea, weakness, dermatitis and respiratory signs. The epidemiology of S. westeri in Australia is largely unknown. Further, molecular techniques have never been employed for detection of S. westeri in horses. This pilot study aimed to assess the utility of a molecular phylogenetic method for the detection of S. westeri in the faeces of foals. Methods Faecal samples were collected from a foal of less than 2 months of age, and eggs of Strongyloides sp. were detected using the modified McMaster technique. DNA was extracted from purified eggs, and a partial fragment of the small subunit of the nuclear ribosomal DNA (18S) was characterised using polymerase chain reaction, DNA sequencing and phylogenetic methods. Results Microscopic examination of faeces revealed small ellipsoidal eggs typical of Strongyloides sp. The 18S sequence generated by PCR in this study revealed 98.4% identity with that of a reference sequence of S. westeri available from GenBank. Phylogenetic analyses revealed a polyphyletic clustering of S. westeri sequences. Conclusion This is the first study reporting the detection of DNA of Strongyloides sp. in faeces of a foal using a molecular phylogenetic approach targeting the variable region of 18S rDNA. It is anticipated that this study will allow future molecular epidemiological studies on S. westeri in horses
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