19,962 research outputs found

    An Approach to Agent-Based Service Composition and Its Application to Mobile

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    This paper describes an architecture model for multiagent systems that was developed in the European project LEAP (Lightweight Extensible Agent Platform). Its main feature is a set of generic services that are implemented independently of the agents and can be installed into the agents by the application developer in a flexible way. Moreover, two applications using this architecture model are described that were also developed within the LEAP project. The application domain is the support of mobile, virtual teams for the German automobile club ADAC and for British Telecommunications

    Industrial Fieldbus Improvements in Power Distribution and Conducted Noise Immunity With No Extra Costs

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    Industrial distributed control continues the move toward networks at all levels. At lower levels, control networks provide flexibility, reliability, and low cost, although perhaps the simplest but most important advantage is the reduced volume of wiring. Powered fieldbuses offer particular notable benefits in system wiring simplification. Nevertheless, very few papers are dealing with the potentials and limitations in power distribution through the bus cable. Only a few of the existent fieldbus standards consider this possibility but often simply as an option without enough technical specifications. In fact, nobody talks about it, but power distribution through the bus and conducted noise disturbances are strongly related. This paper points out and analyzes these limitations and proposes a new low-cost fieldbus physical layer that enlarges power distribution capability of the bus and improves system robustness. We show an industrial application on water desalination plants and the very good results obtained owing to the fieldbus. Finally, we present electromagnetic compatibility test results that verify improvements against electrical fast transients on the sensor/actuator connection side as disturbances usually encountered in harsh-environment industrial applications

    The crowd as a cameraman : on-stage display of crowdsourced mobile video at large-scale events

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    Recording videos with smartphones at large-scale events such as concerts and festivals is very common nowadays. These videos register the atmosphere of the event as it is experienced by the crowd and offer a perspective that is hard to capture by the professional cameras installed throughout the venue. In this article, we present a framework to collect videos from smartphones in the public and blend these into a mosaic that can be readily mixed with professional camera footage and shown on displays during the event. The video upload is prioritized by matching requests of the event director with video metadata, while taking into account the available wireless network capacity. The proposed framework's main novelty is its scalability, supporting the real-time transmission, processing and display of videos recorded by hundreds of simultaneous users in ultra-dense Wi-Fi environments, as well as its proven integration in commercial production environments. The framework has been extensively validated in a controlled lab setting with up to 1 000 clients as well as in a field trial where 1 183 videos were collected from 135 participants recruited from an audience of 8 050 people. 90 % of those videos were uploaded within 6.8 minutes

    Future wireless applications for a networked city: services for visitors and residents

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    Future wireless networks will offer near-ubiquitous high-bandwidth communications to mobile users. In addition, the accurate position of users will be known, either through network services or via additional sensing devices such as GPS. These characteristics of future mobile environments will enable the development of location-aware and, more generally, context-sensitive applications. In an attempt to explore the system, application, and user issues associated with the development and deployment of such applications, we began to develop the Lancaster GUIDE system in early 1997, finishing the first phase of the project in 1999. In its entirety, GUIDE comprises a citywide wireless network based on 802.11, a context-sensitive tour guide application with, crucially, significant content, and a set of supporting distributed systems services. Uniquely in the field, GUIDE has been evaluated using members of the general public, and we have gained significant experience in the design of usable context-sensitive applications. We focus on the applications and supporting infrastructure that will form part of GUIDE II, the successor to the GUIDE system. These developments are designed to expand GUIDE outside the tour guide domain, and to provide applications and services for residents of the city of Lancaster, offering a vision of the future mobile environments that will emerge once ubiquitous high-bandwidth coverage is available in most cities

    Can smartwatches replace smartphones for posture tracking?

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    This paper introduces a human posture tracking platform to identify the human postures of sitting, standing or lying down, based on a smartwatch. This work develops such a system as a proof-of-concept study to investigate a smartwatch's ability to be used in future remote health monitoring systems and applications. This work validates the smartwatches' ability to track the posture of users accurately in a laboratory setting while reducing the sampling rate to potentially improve battery life, the first steps in verifying that such a system would work in future clinical settings. The algorithm developed classifies the transitions between three posture states of sitting, standing and lying down, by identifying these transition movements, as well as other movements that might be mistaken for these transitions. The system is trained and developed on a Samsung Galaxy Gear smartwatch, and the algorithm was validated through a leave-one-subject-out cross-validation of 20 subjects. The system can identify the appropriate transitions at only 10 Hz with an F-score of 0.930, indicating its ability to effectively replace smart phones, if needed
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