1,354,309 research outputs found
A Network Coverage Algorithm for Message Broadcast in Vehicular Networks
No full textn the recent years, ICT use in vehicular technology has expanded very fast. Inter-vehicle communication (IVC) is seen as the natural next step in this evolution whose availability will give rise to the next generation of smart vehicles. As this technology is deployed, a wide range of services varying from safety to entertainment will become factually accessible to passengers. Many of these envisaged services require a one-to-many communication model which demand for intelligent solutions able to propagate the message in areas of the network where it has not been heard before. To this end, we propose an enhancement of an existent optimal message propagation scheme proposed in the context of one dimensional vehicular networks, namely Fast-Broadcast. Our proposal generalizes the former with the objective of guiding message dissemination to an entire area of interest in generic road topologies. Our proposed scheme exploits bloom filter properties to further advance message propagation into the network. We contrast our approach with the original, lightweight state-of-the-art proposal, showing that it fulfills its design objectives
AirCache: A Crowd-Based Solution for Geoanchored Floating Data
No full textThe Internet edge has evolved from a simple consumer of information and data to eager producer feeding sensed data at a societal scale. The crowdsensing paradigm is a representative example which has the potential to revolutionize the way we acquire and consume data. Indeed, especially in the era of smartphones, the geographical and temporal scopus of data is often local. For instance, users' queries are more and more frequently about a nearby object, event, person, location, and so forth. These queries could certainly be processed and answered locally, without the need for contacting a remote server through the Internet. In this scenario, the data is alimented (sensed) by the users and, as a consequence, data lifetime is limited by human organizational factors (e.g., mobility). From this basis, data survivability in the Area of Interest (AoI) is crucial and, if not guaranteed, could undermine system deployment. Addressing this scenario, we discuss and contribute with a novel protocol named AirCache, whose aim is to guarantee data availability in the AoI while at the same time reducing the data access costs at the network edges. We assess our proposal through a simulation analysis showing that our approach effectively fulfills its design objectives
On Using Cashtags to Predict Companies Stock Trends
No full textDifferent theories state that future market values strongly depend on psychological and financial factors: when investors feel positive moods they invest and the value of the stock market increases; conversely, when they feel negative moods they do not invest and the value of the stock market decreases. Today, researchers are trying to exploit the data publicly available in social media and, in particular, different researches showed a connection between Twitter messages and the stock market index. In this paper, we do not focus on a generic stock market index, nor we focus on the sole sentiment analysis. Instead, our goal is to investigate whether tweet messages can be used to predict the future trend (e.g., positive, negative or neutral) of the stocks of specific companies listed in the Dow Jones stock market. In particular, we focus on companies belonging to three different economic sectors (technology, service and health-care) and we consider the trend of 5 different metrics for each stock (e.g., highest, lowest, opening price, etc.) and the trend of 13 different variables of the tweets (e.g., volume, sentiment, tweets with links, etc.). Through an evaluation that employed more than 800,000 tweets, we show that some of the proposed ad-hoc prediction methods well predict (i.e., up to 82% of success) the next day trend of the stock values of specific companies
Intersection Collision: Causes and Avoidance Techniques
No full textA substantial portion of vehicular accidents occur at road intersections [1, 2]. Intersection control devices, stop signs and traffic signals, are used to increase safety and prevent intersection collisions. Nevertheless, these costly and prone to failure devices can contribute to collisions. The evolution of sensing technology and processing capabilities allows addressing the Intersection Collision Avoidance problem; yet, this technology is limited by its line-of-sight requirement. Location-aware technology (on-board digital map, GPS) helps to alleviate the line-of-sight-problem, but leads to increasing market costs of vehicles, thus rendering this technology inaccessible to the masses. Infrastructure-only approaches may represent an immediate solution to the problem; unfortunately, they are also limited by the inherent ineffectiveness of visual warnings. Wireless technology could provide the missing link and give rise to a collaborative solution for the Intersection Collision problem, factually increasing safety and preventing deaths. This chapter gives an analysis of crash dynamics in road intersections and provides a survey of existing Intersection Collision Avoidance mechanism
Social-Aware Delay Tolerant Networking for Mobile-to-Mobile File Sharing
No full textPeer-to-peer (P2P) overlay networks and mobile ad hoc networks share many key characteristics such as self-organization and decentralization; they also face the crucial challenge of providing connectivity in a decentralized, dynamic environment. However, when considering ad hoc networks composed of mobile devices such as smartphones, we cannot rely on the continuous end-to-end path between peers as for classic Internet P2P applications; rather, we have to deal with low node density that creates mobile-disconnected networks. Porting the P2P paradigm into mobile networks to create a mobile-to-mobile file sharing application will create a modern type of delay/disruption tolerant network. In this context, we discuss our new approach for P2P file sharing that considers networks composed of mobile smartphones. As an innovative feature, we leverage on peer mobility to reach data in other disconnected networks by implementing a delay/disruption tolerant network-like store-delegate-and-forward communication model, where a peer can delegate unaccomplished file download tasks to other peers. In order to increase the chances of eventually receiving the requested file while reducing the number of transmitted messages and data, social awareness is exploited by nodes to delegate unaccomplished tasks only to peers that are expected to be encountered again in the future. Copyright © 2011 John Wiley & Sons, Ltd. Peer-to-Peer (P2P) overlay networks and mobile ad hoc networks share many key characteristics such as self-organization and decentralization, both facing the crucial challenge of providing connectivity in a decentralized, dynamic environment. In this context, we discuss our new approach for P2P file-sharing that considers networks composed by mobile smartphones. We leverage on peer mobility to reach data in other disconnected networks by implementing a DTN-like store-delegateand-forward communication model, where a peer can delegate unaccomplished file download tasks to other peers
A mobile sensing and visualization platform for environmental data
No full textThe ubiquity of mobile technology has opened the door to the new era of mobile sensing. Through this new paradigm, physical phenomena can be observed in a distributed way, crowd-sourcing the data measurement tasks to smartphones and/or other popular smart wearables. Mobile sensing and wireless communications can hence be employed to gather data and generate new information and services, benefiting our society. As a proof-of-concept, we have developed a mobile sensing platform able to pervasively collect environmental data. To improve the quality of collected data we have also created an application for pedestrian navigation that works both on smartphones (also using Augmented Reality) and on smartwatches, thus ensuring an appropriate exposition of the mobile device (and its sensors) when collecting data. Furthermore, our navigation app is able to provide users with personalized pedestrian routes that take into account environmental parameters and not only the route length. Finally, we have also devised a web service able to provide graphical visualization and historical evolution of sensed data
Vegas over Access Point: Making Room for Thin Client Game Systems in a Wireless Home
No full textCloud-based entertainment is gaining momentum. With the cost of commodity hardware lowering by the day and the consumer market penetration of in-house digital entertainment systems, a new generation of interactive services has come into being. This new technological wave has launched new content producers and providers that are rapidly adapting to match the consumer demand. In this context, thin client or cloud-based gaming is attracting much attention, shifting the computational burden to the cloud while the consumer enjoys a fat video feed accessed through its thin client via the shared wireless gateway. However, this model of interaction raises new challenges that demand for specific networking solutions aimed at addressing the heterogeneous flow coexistence problem at the home wireless gateway. We propose a solution to this problem by devising a Transmission Control Protocol Vegas-like congestion control algorithm deployed on top of the home gateway. Our solution works out of the box with the standard protocols at the server, router, and client levels, thereby making deployment straightforward. Experimental assessment with real traffic traces shows that our solution addresses the problem effectively
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