1,720,961 research outputs found
SHAPER: a self-healing algorithm producing multi-hop bluetooth scatternets
No full textThis paper deals with scatternet formation in Bluetooth.
A scatternet is an ad hoc network of Bluetooth devices.
Some works in the literature rely on the single-hop hypothesis,
i.e., all devices are in radio visibility of each other. Other works
refer to the more likely circumstance that devices are scattered
in an area where some of them can not directly communicate.
A challenging issue in this latter scenario (often referred to as
multi-hop) is the design of a formation algorithm that: i) operates
in a distributed way; ii) dynamically adapts the topology to the
mobility of devices; iii) forms a scatternet with given topological
properties. In this paper a distributed algorithm for scatternet
formation that gives rise to a tree-like structure is introduced.
The algorithm is shown to present three key properties that make
it innovative with respect to the literature in the field: i) it is fully
distributed and asynchronous; ii) it can be applied in a multi-hop
environment; iii) it operates in order to dynamically adapt the
topology to nodes’ mobility and failures. The key steps and rules
of the algorithm are described and performance results obtained
by simulation are discussed
A MAC protocol for Delay-Bounded applications in Wireless Sensor Networks
No full textThe problem of scheduling packet transmissions
for data gathering in wireless sensor networks is
studied in this paper. A scenario is considered where
different sources contemporarily sense an event and signal
the acquired information to a sink. Energy-latency tradeoffs
for data gathering in sensor networks are explored
by means of Integer Linear Programming Formulations.
The objective of the optimization problems defined is to
find minimum latency and minimum energy optimal data
delivery trees, which are defined as aggregates of flows
from multiple sources to a single receiver.
A new distributed MAC protocol explicitly designed for
Delay-Bounded Applications in Wireless Sensor Networks
(DB-MAC) is also introduced. The primary objective of
DB-MAC is to minimize the latency for delay bounded applications.
Energy consumption is also reduced by means of
a path aggregation mechanism that improves path sharing.
Simulation results show that DB-MAC reduces the latency
up to 70% with respect to a CSMA/CA MAC protocol, with
up to 60% less transmissions. The performance of DBMAC
is shown to be closer than CSMA/CA to the optimal values
of latency and energy consumption
Optimized Scatternet Topologies for Personal Area Networking in Dynamic Environments
No full textIn a scenario where different radio technologies
cooperate to provide access to the Internet and advanced wireless
services to mobile and nomadic users, Bluetooth is considered an
enabling technology for the Personal Area Networking segment.
To this aim, Bluetooth devices should be able to set-up a wireless
multi-hop network with given topological characteristics and with
limited formation delay. In this work SHAPER, a distributed
algorithm for tree scatternet formation, is enhanced to work
in a dynamic environment where devices enter and leave the
Personal Area Network and require a fast interconnection with
an optimized topology. We define a procedure (called SHAPEROPT)
that produces a meshed topology applying a Distributed
Scatternet Optimization Algorithm (DSOA) on the network built
by SHAPER. Nodes are shown to be able to easily join or
leave the scatternet at any time, without compromising the long
term connectivity. Benefits brought by DSOA are shown by
performance analysis, while the delay for network set-up and
reconfiguration in dynamic environments is shown to be within
acceptable bounds
Citation, Intertextuality and Memory in the Middle Ages and Renaissance, edited by Y. Plumley, G. Di Bacco and S. Jossa, Volume One: Text, Music and Image from Machaut to Ariosto, Exeter, University of Exeter Press, 2011 [recensione / review]
No full textRecensione di: Citation, Intertextuality and Memory in the Middle Ages and Renaissance, edited by Y. Plumley, G. Di Bacco and S. Jossa, Volume One: Text, Music and Image from Machaut to Ariosto, Exeter, University of Exeter Press, 2011.Review of: Citation, Intertextuality and Memory in the Middle Ages and Renaissance, edited by Y. Plumley, G. Di Bacco and S. Jossa, Volume One: Text, Music and Image from Machaut to Ariosto, Exeter, University of Exeter Press, 2011
'Auctores' and 'auctoritas' in the preface to Angelo Poliziano's 'Miscellaneorum centuria prima'
No full textStudio sul concetto di auctoritas quale emerge dalla raffinata ed eruditissima riflessione filologica esperita da Angelo Poliziano nella prefazione della prima centuria dei Miscellanea
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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