21,954 research outputs found

    Hybrid-Vehfog: A Robust Approach for Reliable Dissemination of Critical Messages in Connected Vehicles

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    Vehicular Ad-hoc Networks (VANET) enable efficient communication between vehicles with the aim of improving road safety. However, the growing number of vehicles in dense regions and obstacle shadowing regions like Manhattan and other downtown areas leads to frequent disconnection problems resulting in disrupted radio wave propagation between vehicles. To address this issue and to transmit critical messages between vehicles and drones deployed from service vehicles to overcome road incidents and obstacles, we proposed a hybrid technique based on fog computing called Hybrid-Vehfog to disseminate messages in obstacle shadowing regions, and multi-hop technique to disseminate messages in non-obstacle shadowing regions. Our proposed algorithm dynamically adapts to changes in an environment and benefits in efficiency with robust drone deployment capability as needed. Performance of Hybrid-Vehfog is carried out in Network Simulator (NS-2) and Simulation of Urban Mobility (SUMO) simulators. The results showed that Hybrid-Vehfog outperformed Cloud-assisted Message Downlink Dissemination Scheme (CMDS), Cross-Layer Broadcast Protocol (CLBP), PEer-to-Peer protocol for Allocated REsource (PrEPARE), Fog-Named Data Networking (NDN) with mobility, and flooding schemes at all vehicle densities and simulation times

    The Use of Social Media by UK Local Resilience Forums

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    The potential uses of social media in the field of emergency preparedness, resilience and response (EPRR) are varied and interesting. The UK government have produced guidance documents for its use in the UK EPRR field but evidence of use is poorly documented and appears sporadic. This paper presents the results of a survey of Local Resilience Forums (LRF) in the UK on their use and engagement with social media. The findings suggest that the level of application of social media strategies as emergency planning or response tools varied significantly between the LRFs. While over 90percent of respondents claimed that their LRF used social media as part of their strategy, most of this use was reactive or passive, rather than proactive and systematic. The various strategies employed seem to be linked most strongly to local expertise and the existence of social media ‘champions’ rather than to the directives and guidance emerging from government

    Requirement analysis for building practical accident warning systems based on vehicular ad-hoc networks

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    An Accident Warning System (AWS) is a safety application that provides collision avoidance notifications for next generation vehicles whilst Vehicular Ad-hoc Networks (VANETs) provide the communication functionality to exchange these notifi- cations. Despite much previous research, there is little agreement on the requirements for accident warning systems. In order to build a practical warning system, it is important to ascertain the system requirements, information to be exchanged, and protocols needed for communication between vehicles. This paper presents a practical model of an accident warning system by stipulating the requirements in a realistic manner and thoroughly reviewing previous proposals with a view to identify gaps in this area

    Toward Reliable Contention-aware Data Dissemination in Multi-hop Cognitive Radio Ad Hoc Networks

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    This paper introduces a new channel selection strategy for reliable contentionaware data dissemination in multi-hop cognitive radio network. The key challenge here is to select channels providing a good tradeoff between connectivity and contention. In other words, channels with good opportunities for communication due to (1) low primary radio nodes (PRs) activities, and (2) limited contention of cognitive ratio nodes (CRs) acceding that channel, have to be selected. Thus, by dynamically exploring residual resources on channels and by monitoring the number of CRs on a particular channel, SURF allows building a connected network with limited contention where reliable communication can take place. Through simulations, we study the performance of SURF when compared with three other related approaches. Simulation results confirm that our approach is effective in selecting the best channels for efficient and reliable multi-hop data dissemination

    How can we use mobile apps for disaster communications in Taiwan: Problems and possible practice

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    The growth rate of global smart phone in 2010 is as high as 78.1%, showing that smart phone gradually becomes the mainstream in the mobile phone market. Smart phone has the function of installing applications, provides users with more diversified mobile value-added services and will change users' communication habits in the future. Mobile communication follows the development trend of 3G and WiMAX, make users can link with mobile software stores through internet, downloading all kinds of applications, which has provided human beings with more diversified information, and gradually changed people's living habits. With the widespread of smart phone in Taiwan and many mobile applications start to go popular in market, people are crazy about downloading mobile applications, and different applications create different types of communications. Within a trend of smart phone and massive mobile apps go popular in Taiwan, what can we do to apply these tools for disaster communications? And compare to other infrastructure-level support, is mobile app a feasible route for disaster communications? What is the possible uses and challenges. --

    PACMAS state of media and communication report 2013

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    The PACMAS State of Media and Communication Report 2013 was undertaken through a partnership between RMIT University (Australia), the University of Goroka (Papua New Guinea) and UNITEC (New Zealand). The research for this report was developed and undertaken between June 2012 and April 2013 across 14 Pacific Island nations: Cook Islands, Federated States of Micronesia, Fiji, Kiribati, Republic of the Marshall Islands, Republic of Nauru, Niue, Republic of Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu. The report provides a regional overview of the PACMAS key components (Media Policy, Media Systems, Media Capacity Building and Media Content) as they emerged through 212 interviews focused upon the six PACMAS strategic areas. It also provides basic background information, an overview of the media and communications landscape and discusses in detail media and communications technicians; emergency broadcast systems, Technical and Vocational Education and Training (TVETs), media associations, climate change and non-communicable diseases (NCDs). For this reason, observations on the four PACMAS components should be understood to represent changes in the media and communication environment based upon an investigation focused on the PACMAS strategic activities. Part 1 & Part II of the report make up a Regional Overview of the State of Media and Communication in the Pacific.  The report also includes 14 separate Country Reports which provide additional information on the media and communications landscape specific to each of the Pacific Island countries included in the PACMAS program.  The country reports were written with the objectives of the PACMAS program in mind, however they may have utility for media, communication and development practitioners across the region

    Six emerging trends in media and communications - occasional paper

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    This paper examines six emerging trends in media and communications, which highlight that consumers are increasingly using personalised access pathways to communications and content services that cut across different networks, devices and services. Introduction The ACMA monitors industry and consumer data to identify changes in the media and communications environment and their impact on regulatory settings. Previous ACMA research, such as Broken concepts1 and the Emerging issues2 series of papers, has identified areas of regulatory strain resulting from changes in this environment. The ACMA’s 2014 data collection program highlighted six further trends that are of particular interest as they indicate challenges to the regulatory frameworks within which the ACMA works. These trends illustrate how developments in communications device technologies and over-the-top (OTT) services and content offer both: new opportunities for businesses and individuals as consumers and citizens potential challenges to confident and optimal use of these new services. The evolving media and communications environment offers new ways to understand and achieve policy objectives, and may expose alternatives to ’black-letter’ regulation. However, changes in media and communications can also strain the effectiveness and efficiency of existing regulatory settings designed in an environment where content and communication services have been delivered by network owners over dedicated networks and devices. The selected trends highlight that consumers are increasingly using personalised access pathways to communications and content services that cut across different networks, devices and services. This paper looks at the implications of these six trends for existing regulatory settings
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