1,720,991 research outputs found
T1-D: Ad hoc-casting & scheduling protocols: DSMA: an access method for MIMO ah hoc networks based on distributed scheduling
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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
A detailed analytical and simulation study of geographic random forwarding
No full textIn this paper, we extend previous work on geographic random forwarding (GeRaF) by considering a more efficient paradigm whereby on/off cycles are exploited and every node can participate to packet relaying, as long as it wakes up during any handshake procedure. The protocol is fully distributed, as routing decisions are made hop by hop based on geographic metrics and using a joint channel access/routing procedure, like in the first version of GeRaF. In addition, a previously defined analytical model for GeRaF is used to analyze the protocol, after extending it to cover the new channel access and relay selection procedure. The model is employed to find optimal choices for the parameters of the protocol, before comparing analytical results with ns2 simulations. Results confirm that the geographic paradigm remains a very good solution for energy-constrained, density-constrained, and latency-constrained networks, and that small yet very effective protocol optimizations can achieve remarkable performance improvements. Copyright (c) 2011 John Wiley & Sons, Ltd
A detailed simulation study of geographic random forwarding (GERAF) in wireless sensor networks
No full textThis paper provides a thorough performance evaluation of the GeRaF protocol in a multi-hop wireless sensor network scenario. The contributions of the paper are twofold. First we provide an in-depth discussion on the impact of the different protocol parameters and of network features on the protocol performance. Based on the results of the first part of our investigation we design variants of the basic GeRaF protocol which are able to significantly decrease the packet latency and to increase the packet delivery ratio. The study presented in this paper is the first attempt to thoroughly characterize the performance of GeRaF and is a necessary step toward understanding the real protocol behavior before implementing it on real devices
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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