31 research outputs found

    Smart traffic management protocol based on VANET architecture

    Get PDF
    Nowadays one of the hottest theme in wireless environments research is the application of the newest technologies to road safety problems and traffic management exploiting the (VANET) architecture. In this work, a novel protocol that aims to achieve a better traffic management is proposed. The overal system is able to reduce traffic level inside the city exploiting inter-communication among vehicles and support infrastructures also known as (V2V) and (V2I) communications. We design a network protocol called (STMP) that takes advantages of IEEE 802.11p standard. On each road several sensors system are placed and they are responsible of monitoring. Gathered data are spread in the network exploiting ad-hoc protocol messages. The increasing knowledge about environment conditions make possible to take preventive actions. Moreover, having a realtime monitoring of the lanes it is possible to reveal roads and city blocks congestions in a shorter time. An external entity to the (VANET) is responsible to manage traffic and rearrange traffic along the lanes of the city avoiding huge traffic levels

    Vehicular networking enhancement and multi-channel routing optimization, based on multi-objective metric and minimum spanning tree

    Get PDF
    Vehicular Ad hoc NETworks (VANETs) represent a particular mobile technology that permits the communication among vehicles, offering security and comfort. Nowadays, distributed mobile wireless computing is becoming a very important communications paradigm, due to its flexibility to adapt to different mobile applications. VANETs are a practical example of data exchanging among real mobile nodes. To enable communications within an ad-hoc network, characterized by continuous node movements, routing protocols are needed to react to frequent changes in network topology. In this paper, the attention is focused mainly on the network layer of VANETs, proposing a novel approach to reduce the interference level during mobile transmission, based on the multi-channel nature of IEEE 802.11p (1609.4) standard. In this work a new routing protocol based on Distance Vector algorithm is presented to reduce the delay end to end and to increase packet delivery ratio (PDR) and throughput in VANETs. A new metric is also proposed, based on the maximization of the average Signal-to-Interference Ratio (SIR) level and the link duration probability between two VANET nodes. In order to relieve the effects of the co-channel interference perceived by mobile nodes, transmission channels are switched on a basis of a periodical SIR evaluation. A Network Simulator has been used for implementing and testing the proposed idea

    Routing Optimization in Vehicular Networks: A New Approach Based on Multiobjective Metrics and Minimum Spanning Tree

    Get PDF
    Recently, distributed mobile wireless computing is becoming a very important communications paradigm, due to its flexibility to adapt to different mobile applications. As many other distributed networks, routing operations assume a crucial importance in system optimization, especially when considering dense urban areas, where interference effects cannot be neglected. In this paper a new routing protocol for VANETs and a new scheme of multichannel management are proposed. In particular, an interference-aware routing scheme, for multiradio vehicular networks, wherein each node is equipped with a multichannel radio interface is investigated. NS-2 has been used to validate the proposed Multiobjective routing protocol (MO-RP) protocol in terms of packet delivery ratio, throughput, end-to-end delay, and overhead

    The interaction of Thrombospondins with extracellular matrix proteins

    Get PDF
    The thrombospondins (TSPs) are a family of five matricellular proteins that appear to function as adapter molecules to guide extracellular matrix synthesis and tissue remodeling in a variety of normal and disease settings. Various TSPs have been shown to bind to fibronectin, laminin, matrilins, collagens and other extracellular matrix (ECM) proteins. The importance of TSP-1 in this context is underscored by the fact that it is rapidly deposited at the sites of tissue damage by platelets. An association of TSPs with collagens has been known for over 25 years. The observation that the disruption of the TSP-2 gene in mice leads to collagen fibril abnormalities provided important in vivo evidence that these interactions are physiologically important. Recent biochemical studies have shown that TSP-5 promotes collagen fibril assembly and structural studies suggest that TSPs may interact with collagens through a highly conserved potential metal ion dependent adhesion site (MIDAS). These interactions are critical for normal tissue homeostasis, tumor progression and the etiology of skeletal dysplasias

    <<A>> proposal of efficient routing techniques and intelligent vehicular traffic management in the smart cities context, through distributed wireless networks

    No full text
    Scuola di Dottorato "Archimede"in Scienze, Comunicazione e Tecnologie, indirizzo:Scienze e Tecnologie dei Sistemi Complessi, Ciclo XXVIII, a.a.2015-2016In this thesis, the design of e cient techniques for routing protocol suitable to Vehicular Ad-hoc NETworks (VANETs) has been pro- posed. In particular, the aims of the proposed protocols are to reduce interference issues, due to the data transmissions in wireless environ- ment. The proposed protocols use time series prediction models and also multi-objective metric, based on the evaluation of co-channel in- terference levels, end-to-end delay, and link duration probability along the di erent links from sources towards destinations. These param- eters are modelled through an optimization problem. The key fac- tors are to exploit the advantages available to the Standard 802.11p, based on a dynamic allocation mechanism of the DSRC spectrum, aimed at the reduction of the co-channel interference and the maxi- mization of the link duration probability (two key issues in vehicular environments). Another topic discussed in this thesis is related to the smart vehicular tra c management through VANETs infrastructure and communications(V2I and V2V). A distributed algorithm with the aim to build less congested path for the vehicles in a urban scenario has been developed. It is also considered the problem regarding to enhance air quality around the cities reducing the vehicles CO2 emis- sions. There are di erent causes related to the CO2 emissions such as the average travelled time spent by vehicles inside the city and their average speed. Hence, with a better tra c management the average time spent by the vehicles in the city will be considerably reduced as well as CO2 emissions. These results are demonstrated in a discrete event simulator by using also real tra c dataUniversità della Calabri

    CTA – the World’s largest ground-based gamma-ray observatory

    Get PDF
    International audienc

    Cherenkov Telescope Array Contributions to the 35th International Cosmic Ray Conference (ICRC2017)

    Full text link
    List of contributions from the Cherenkov Telescope Array Consortium presented at the 35th International Cosmic Ray Conference, July 12-20 2017, Busan, Korea.Comment: Index of Cherenkov Telescope Array conference proceedings at the ICRC2017, Busan, Kore

    Prototype Open Event Reconstruction Pipeline for the Cherenkov Telescope Array

    No full text
    The Cherenkov Telescope Array (CTA) is the next-generation gamma-ray observatory currently under construction. It will improve over the current generation of imaging atmospheric Cherenkov telescopes (IACTs) by a factor of five to ten in sensitivity and it will be able to observe the whole sky from a combination of two sites: a northern site in La Palma, Spain, and a southern one in Paranal, Chile. CTA will also be the first open gamma-ray observatory. Accordingly, the data analysis pipeline is developed as open-source software. The event reconstruction pipeline accepts raw data of the telescopes and processes it to produce suitable input for the higher-level science tools. Its primary tasks include reconstructing the physical properties of each recorded shower and providing the corresponding instrument response functions. ctapipe is a framework providing algorithms and tools to facilitate raw data calibration, image extraction, image parameterization and event reconstruction. Its main focus is currently the analysis of simulated data but it has also been successfully applied for the analysis of data obtained with the first CTA prototype telescopes, such as the Large-Sized Telescope 1 (LST-1). pyirf is a library to calculate IACT instrument response functions, needed to obtain physics results like spectra and light curves, from the reconstructed event lists. Building on these two, protopipe is a prototype for the event reconstruction pipeline for CTA. Recent developments in these software packages will be presented
    corecore