1,720,992 research outputs found
Supporting Privacy Preservation by Distributed and Federated Learning on the Edge
No full textThe H2020 TEACHING project puts forward a human-centered vision for adapting and optimising autonomous applications, leveraging users’ physiological, emotional and cognitive states. Such a goal can be achieved by building a distributed, embedded and federated learning system complemented by methods and tools to enforce its dependability, security, and privacy preservation
Adaptive bandwidth partitioning among TCP elephant connections over multiple rain-faded satellite channels
No full textThe assignment of a common bandwidth resource to TCP connections over a satellite channel is considered in the paper. The connections are grouped according to their source-destination pairs, corresponding to up- and down-link channels traversed, and each group may experience different fading conditions. By exploiting the tradeoff between bandwidth and channel redundancy (as determined by bit and coding rates) in the maximization of TCP goodput, an overall optimization problem is constructed, which can be solved by numerical techniques. Different relations between goodput maximization and fairness of the allocation are investigated. The allocation strategies are tested and compared in a real dynamic fading environment. © Springer-Verlag Berlin Heidelberg 2005
On Cloud-Based Multisource Reliable Multicast Transport in Broadband Multimedia Satellite Networks
Get PDFOn elastic traffic via contention resolution diversity slotted aloha satellite access
No full textSummary This paper presents a performance study relative to the coupling of the Transmission Control Protocol (TCP) with the Contention Resolution Diversity slotted aloha (CRDSA) protocol, in the case of greedy TCP connections (also called elephants) on Digital Video Broadcasting-Return Channel via a geostationary satellite. CRDSA, which takes advantage of interference cancellation algorithms for collision/contention resolution, has already exhibited interesting performance when the power levels of all received bursts are perfectly balanced. In this paper, we extend the study to a more realistic case, where a certain spreading of the bursts' power levels is taken into account. The consequent capture effect even facilitates the collision resolution mechanism and yields an improvement in the overall TCP performance with respect to the balanced case. Furthermore, in certain conditions, the adoption of packet level forward error correction allows achieving even higher peaks of throughput than the expected ones
Advances on Elastic Traffic via M2M Satellite User Terminals
No full textOwing to the variety of traffic profiles that Machine to Machine and Internet of Things applications may generate, this work studies the applicability of the Contention Resolution Diversity Slotted ALOHA (CRDSA) random access scheme, as in the DVB-RCS2 standard, when clusters of sensor nodes exchange data via satellite toward a sink via short-lived TCP/IP connections. In this scenario, uncorrelated sensor sources generate measurements, which are multiplexed by a satellite terminal, before being encapsulated and delivered through TCP/IP flows. This work aims at investigating the scalability in terms of number of concurrent satellite terminals, which can successfully transfer their own data with a small delivery delay in order to avoid congestion phenomena at MAC layers, which may induce collision storms. This work assesses the best practice for M2M elastic traffic wia random access satellite, investigating on crosslayer interactions between access layer and transport/application layers
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
- …
