492,625 research outputs found

    Device-Centric Cooperation in Mobile Networks

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    The increasing popularity of applications such as video streaming in today's mobile devices introduces higher demand for throughput, and puts a strain especially on cellular links. Cooperation among mobile devices by exploiting both cellular and local area connections is a promising approach to meet the increasing demand. In this paper, we consider that a group of cooperative mobile devices, exploiting both cellular and local area links and within proximity of each other, are interested in the same video content. Traditional network control algorithms introduce high overhead and delay in this setup as the network control and cooperation decisions are made in a source-centric manner. Instead, we develop a device-centric stochastic cooperation scheme. Our device-centric scheme; DcC allows mobile devices to make control decisions such as flow control, scheduling, and cooperation without loss of optimality. Thanks to being device-centric, DcC reduces; (i) overhead; i.e., the number of control packets that should be transmitted over cellular links, so cellular links are used more efficiently, and (ii) the amount of delay that each packet experiences, which improves quality of service. The simulation results demonstrate the benefits of DcC

    Control mechanisms for mobile devices

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    In this paper we consider control mechanisms for mobile devices in a stochastic environment. In particular, we consider a device in n-dimensional space subject to Brownian perturbations where a control mechanism moves the device towards its target location at a speed which is a function of its displacement. For this scenario, we construct stochastic differential equations for the mobility process and solve for the steady state probability density function of displacement. From this we are able to give general solutions to key metrics such as displacement outage (the long term probability of exceeding a given distance from the target), connectivity probability (derived from the SNR distribution in a Rayleigh channel with pathloss), the mean time at which the device first exceeds a given distance from the target, and the mean kinetic energy required by the control mechanism. We evaluate these metrics for important special cases of the control mechanism and also study the optimization problem of minimizing kinetic energy over the parameters of the control function

    Remote Control and Monitoring of Smart Home Facilities via Smartphone with Wi-Fly

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    Due to the widespread ownership of smartphone devices, the application of mobile technologies to enhance the monitoring and control of smart home facilities has attracted much academic attention. This study indicates that tools already in the possession of the end user can be a significant part of the specific context-aware system in the smart home. The behaviour of the system in the context of existing systems will reflect the intention of the client. This model system offers a diverse architectural concept for Wireless Sensor Actuator Mobile Computing in a Smart Home (WiSAMCinSH) and consists of sensors and actuators in various communication channels, with different capacities, paradigms, costs and degree of communication reliability. This paper focuses on the utilization of end users’ smartphone applications to control home devices, and to enable monitoring of the context-aware environment in the smart home to fulfil the needs of the ageing population. It investigates the application of an iPhone to supervise smart home monitoring and control electrical devices, and through this approach, after initial setup of the mobile application, a user can control devices in the smart home from different locations and over various distances

    Development of PAN (personal area network) for Mobile Robot Using Bluetooth Transceiver

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    In recent years, wireless applications using radio frequency (RF) have been rapidly evolving in personal computing and communications devices. Bluetooth technology was created to replace the cables used on mobile devices. Bluetooth is an open specification and encompasses a simple low-cost, low power solution for integration into devices. This research work aim was to provide a PAN (personal area network) for computer based mobile robot that supports real-time control of four mobile robots from a host mobile robot. With ad hoc topology, mobile robots may request and establish a connection when it is within the range or terminated the connection when it leaves the area. A system that contains both hardware and software is designed to enable the robots to participate in multi-agent robotics system (MARS). Computer based mobile robot provide operating system that enabled development of wireless connection via IP address

    Motivation and mobile devices: exploring the role of appropriation and coping strategies

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    There has been interest recently in how mobile devices may be motivating forces in the right contexts: for example, one of the themes for the IADIS International Conference on Mobile Learning in 2007 was ‘Affective Factors in Learning with Mobile Devices’ (http://www.mlearningconf. org). The authors have previously proposed six aspects of learning with mobile devices in informal contexts that might be motivating: control over learners’ goals, ownership, fun, communication, learning-in-context and continuity between contexts. How do these motivational features relate to theoretical accounts of what motivates people to use mobile devices and learn in technology- rich contexts? In this exploratory paper we consider two different candidates for such theoretical approaches. One is technology appropriation—the process by which technology or particular technological artefacts are adopted and shaped in use. Two different approaches to technology appropriation are discussed in order to explore the relationship between the different aspects of appropriation and motivation; that of Carroll et al. and that of Waycott. Both appropriation frameworks have been developed in the context of using mobile devices, but neither has a specific focus on learning. By contrast, the second theoretical approach is JĂ€rvelĂ€ et al.’s model of coping strategies, which is specifically concerned with learning with technologies, although not with mobile technologies in particular. The paper draws on case-study data in order to illustrate and discuss the extent to which these two approaches are helpful in informing our understanding of the motivating features of using mobile devices for informal learning

    Evaluating Mobile Device Cleaning Policies in the NHS

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    Introduction The use of mobile devices within healthcare settings by staff, patients and visitors is widespread and growing. DoH guidance states that patients should be allowed the widest possible use of mobile phones. For staff mobile devices have become an essential aspect of their day-to-day professional and personal lives. There is, however, clear evidence that phones/tablets can be contaminated with pathogens, which may survive for prolonged periods before being transferred onto hands or other surfaces.   Methods A FoI request for “all current policies or guidelines that make reference to the use and management of mobile phones and tablet devices in the healthcare environment, by staff, service users, and visitors – this applies to both personal and institutionally-owned devices”, was sent to NHS institutions across England, Scotland and Wales with a response rate of 96% (n=252).   Results 22% of organisations had no policy in place, with ≈11% stating that this would be considered policy reviews. Organisations that acknowledged the issue responded that staff were informed of disinfection procedures: e.g. ‘the normal cleaning schedule’ or the use of universal sanitizing/detergent wipes. Many organisations referred to their Cleaning and Decontamination policy, however none of these explicitly mentioned mobile devices. Instead, the general advice for electrical devices was to follow manufacturer’s instructions, as using any other process might invalidate warranties. Where specific cleaning policies were in place they advocated the use of ‘general purpose/universal detergent wipes’ without any technical justification. Multiple organisations suggested that existing hand decontamination procedures were sufficient to address this issue.   Discussion There is no consistency in infection control advice regarding the potential risks posed by the use of mobile devices. Regular cleaning may be a solution, but there is little evidence evaluating the available methods. The literature in this field calls for clear evidence-based guidelines for cleaning and disinfecting mobile devices
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