14,609 research outputs found

    Autonomous and context-aware scheduling for public displays using place-based tag clouds

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    Public displays are an increasingly ubiquitous element of our socio-digital landscape with a strong potential to become key building blocks for AmI. For that purpose, they should have the ability to dynamically and autonomously select content from web sources according to the relevance of their content to the Continuous flow of social settings around the display. In this paper, we explore the creation of a public display system that evaluates the relevance of content from web sources and selects the most relevant content according to a dynamic tag cloud that incorporates static place definitions, but is also sensitive to the people around the display. We have developed and evaluate a dynamic content selection system based on those principles.. The results show that place visitors recognize the sensitivity of the system to their demands and that a place tag cloud can provide an important element for the interpretation of place and for the combination of the interests expressed by the place owner and the multiple place visitors.The first author was supported by a Portuguese Foundation for Science and Technology scholarship (SFRH/BD/31292/2006)

    Air quality measured in a classroom served by roof mounted natural ventilation windcatchers

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    This study examines air quality measured in two classrooms in a UK school, which uses two different forms of natural ventilation, over an eight month period. The first classroom is an internal room that contains a top-down natural ventilation system known as a “Windcatcher”. The room also has a separate mechanical extract fan. The second classroom is ventilated using windows and doors that open to the outside. This study focuses on measuring the performance of a Windcatcher and reviews its potential to replace ventilation provided by conventional windows. Potential benefits of Windcatchers include the ability to provide night cooling without posing a security risks, and daytime ventilation without relying upon opening windows. The study will examine Windcatcher performance in terms of air quality delivered in the first room, and then compare results with measurements obtained for a room that uses conventional opening windows. The study will also review the effectiveness of Windcatchers in meeting the regulatory standards for naturally ventilated classrooms, as set out by the UK Government. The air quality measurements reported demonstrate that the classroom utilising a Windcatcher was able to meet the UK Government standards for carbon dioxide and temperature, while the classroom relying solely on windows failed to meet the carbon dioxide requirements. Furthermore, the study demonstrates that Windcatchers provide significant night cooling and increase air exchange rates. Windcatchers do, therefore, have a significant role to play in meeting ventilation requirements in schools

    A CF3I-based SDD Prototype for Spin-independent Dark Matter Searches

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    The application of Superheated Droplet Detectors (SDDs) to dark matter searches has so far been confined to the light nuclei refrigerants C2ClF5 and C4F10 (SIMPLE and PICASSO, respectively), with a principle sensitivity to spin-dependent interactions. Given the competitive results of these devices, as a result of their intrinsic insensitivity to backgrounds, we have developed a prototype trifluoroiodomethane (CF3I)-loaded SDD with increased sensitivity to spin-independent interactions as well. A low (0.102 kgd) exposure test operation of two high concentration, 1 liter devices is described, and the results compared with leading experiments in both spin-dependent and -independent sectors. Although competitive in both sectors when the difference in exposures is accounted for, a problem with fracturing of the detector gel must be addressed before significantly larger exposures can be envisioned.Comment: revised and updated; accepted Astrop. Phy

    A systematic approach to the characterisation of human impact injury scenarios in sport

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    Background: In contact sports (e.g. American football or rugby), injuries resulting from impacts are widespread. There have been several attempts to identify and collate, within a conceptual framework, factors influencing the likelihood of an injury. To effectively define an injury event it is necessary to systematically consider all potential causal factors but none of the previous approaches are complete in this respect. Aims: Firstly, to develop a superior deterministic contextual sequential (DCS) model to promote a complete and logical description of interrelated injury event factors. Secondly, to demonstrate systematic use of the model to construct enhanced perspectives for impact-injury research. Method: Previous models were examined and elements of best practice synthesised into a new DCS framework description categorising the types of causal factors influencing injury. The approach’s internal robustness is demonstrated by consideration of its completeness, lack of redundancy, and logical consistency. Results: The model’s external validity and worth are demonstrated through its use to generate superior descriptive injury models, experimental protocols and intervention opportunities. Comprehensive research perspectives have been developed using a common rugby impact-injury scenario as an example; this includes: a detailed description of the injury event, an experimental protocol for a human-on-surrogate reconstruction, and a series of practical interventions in the sport of rugby aimed at mitigating the risk of injury. Conclusions: Our improved characterisation tool presents a structured approach to identify pertinent factors relating to an injury

    Voice Hacking Proof of Concept: Using Smartphones to Spread Ransomware to Traditional PCs

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    This paper presents a working proof of concept that demonstrates the ability to deploy a sequence of hacks, triggered by speaking a smartphone command, to launch ransomware and other destructive attacks against vulnerable Windows computers on any wireless network the phone connects to after the voice command is issued. Specifically, a spoken, broadcast, or pre-recorded voice command directs vulnerable Android smartphones or tablets to a malicious download page that compromises the Android device and uses it as a proxy to run software designed to scan the Android device’s local area network for Windows computers vulnerable to the EternalBlue exploit, spreading a ransomware-like application to those PCs, and executing it remotely. In addition to describing the proof-of-concept attack in detail, the authors propose several remedies individuals and organizations can use to prevent such attacks

    Two isoperimetric inequalities for the Sobolev constant

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    In this note we prove two isoperimetric inequalities for the sharp constant in the Sobolev embedding and its associated extremal function. The first such inequality is a variation on the classical Schwarz Lemma from complex analysis, similar to recent inequalities of Burckel, Marshall, Minda, Poggi-Corradini, and Ransford, while the second generalises an isoperimetric inequality for the first eigenfunction of the Laplacian due to Payne and Rayner.Comment: 11 page

    Higher Order Chemistry Models in the CFD Simulation of Laser-Ablated Carbon Plumes

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    Production of single-walled carbon nanotubes (SWNT) has taken place for a number of years and by a variety of methods such as laser ablation, chemical vapor deposition, and arc-jet ablation. Yet, little is actually understood about the exact chemical kinetics and processes that occur in SWNT formation. In recent time, NASA Johnson Space Center has devoted a considerable effort to the experimental evaluation of the laser ablation production process for SWNT originally developed at Rice University. To fully understand the nature of the laser ablation process it is necessary to understand the development of the carbon plume dynamics within the laser ablation oven. The present work is a continuation of previous studies into the efforts to model plume dynamics using computational fluid dynamics (CFD). The ultimate goal of the work is to improve understanding of the laser ablation process, and through that improved understanding, refine the laser ablation production of SWNT

    CMR Features in Cardiac Sarcoidosis

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    Sarcoidosis is a multisystemic disorder of unknown aetiology characterised by the formation of noncaseating epithelioid cell granuloma involving various organ systems. Cardiac involvement has an important prognostic factor as it can present with life-threatening arrythmias and sudden death. Here, we present a case of cardiac sarcoidosis in a 46-year-old gentleman who presented with nonspecific signs and symptoms. We also discuss diagnostic difficulties especially when cardiac involvement is the only clinical sign. In this case, cardiac magnetic resonance (CMR) played an important role in the diagnosis and followup of our patient
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