1,720,957 research outputs found
Dataset supporting the Southampton PhD Thesis - "Intelligent routing in urban vehicular networks".
No full textThis dataset includes all simulation files and results produced throughout the PhD, along with the Vehicular Simulator MATLAB code and the instructions required to assemble it
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Intelligent routing in urban vehicular networks.
No full textResults demonstrate that I-TAR can achieve up to ~19% higher average packet-delivery-ratio (APDR) compared to the state-of-the-art. Additionally, the hybrid approach improves the APDR and average end-to-end delay (AEED) performances of I-TAR by 4% and about 8%, respectively. Under a more realistic scenario, where node availability is considered, a decline of up to ~51% decline in APDR performance is observed, whereas the proposed HI-TAR can increase the APDR performance by up to 50% compared to both I-TAR and the state-of-the-art. Finally, when multiple source-destination vehicle pairs are considered simultaneously, all the schemes that model and consider node availability, i.e. limited-availability, achieve from 72.2% to 82.3% lower APDR, when compared to those that do not, i.e. assuming full-availability. However, HI-TAR still provides 34.6% better APDR performance than I-TAR, and ~40% more than the state-of-the-art.<br/
Dataset for 'ANTS'21 W5 AIMLECV - Route Lifetime Analysis in Vehicular Networks'
No full textThis is the dataset of the accepted paper (Nov, 2021): T. Ivanescu, H. Yetgin, M. El-Hajjar, G. Merrett, "Route Lifetime Analysis for Vehicular Networks". </span
Multi-source multi-destination hybrid infrastructure-aided traffic aware routing in V2V/I networks
No full textThe concept of the “connected car” offers the potential for safer, more enjoyable and more efficient driving and eventually autonomous driving. However, in urban Vehicular Networks (VNs) , the high mobility of vehicles along roads poses major challenges to the routing protocols needed for a reliable and flexible vehicular communications system. Thus, urban VNs rely on static Road-Side-Units (RSUs) to forward data and to extend coverage across the network. In this paper, we first propose a new Q-learning-based routing algorithm, namely Infrastructure-aided Traffic-Aware Routing (I-TAR), which leverages the static wired RSU infrastructure for packet forwarding. Then, we focus on the multi-source, multi-destination problem and the effect this imposes on node availability, as nodes also participate in other communications paths. This motivates our new hybrid approach, namely Hybrid Infrastructure-aided Traffic Aware Routing (HITAR)that aims to select the best Vehicle-to-Vehicle/Infrastructure (V2V/I) route. Our findings demonstrate that I-TAR can achieve up to 19% higher average packet-delivery-ratio (APDR) compared to the state-of-the-art. Under a more realistic scenario, where node availability is considered, a decline of up to 51% in APDR performance is observed, whereas the proposed HI-TAR in turn can increase the APDR performance by up to 50% compared to both I-TAR and the state-of-the-art. Finally, when multiple source destination vehicle pairs are considered, all the schemes that model and consider node availability, i.e. limited-availability, achieve from 72.2% to 82.3% lower APDR, when compared to those that do not, i.e. assuming full-availability. However, HI-TAR still provides 34.6% better APDR performance than I-TAR, and ∼40% more than the state-of-the-art
Route lifetime analysis for vehicular networks
No full textVehicular communications have a critical role in the future intelligent transportation systems as they promise safer, more efficient and enjoyable driving. Multi-hop communications can be employed through routing protocols in order to achieve increased data transmission and coverage. However, most vehicular applications encounter significant challenges due to the increased mobility of the vehicles. This leads to transient communication links, which may significantly degrade the overall routing performance. Additionally, efficient routing techniques are required in order to achieve a reliable and flexible vehicular communications system. In this paper, we provide a framework for route lifetime analysis based on an exhaustive search routing technique to set an upper bound on the lifetime, which can inform the design of routing techniques. We then highlight the purpose of our framework by comparing the upper bound to a shortest-path forwarding mechanism based on global state routing (GSR), chosen as a routing example. The route lifetime is measured in order to reveal the trade-off between the structure and dimension of the road-network and performance requirements as a fundamental research baseline for investigating and developing sophisticated routing models for vehicular networks. Our results reveal that, on average, the shortest-path route lifetime is sub-optimal 11.56% of the time compared to the upper bound route lifetime. Then, we provide a trade-off between the road-network dimensions and the quality-of-service (QoS) requirements, and finally demonstrate that on average, under channel fading conditions, 7 times higher route lifetime could be achieved in a line-of-sight (LOS) scenario compared to its non-line-of-sight (NLOS) counterpart
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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