1,721,012 research outputs found
Packet management techniques for measurement based end-to-end admission control in IP networks
No full textEnd-to-end Measurement Based connection Admission Control (EMBAC) mechanisms have been proposed to support real-time flows quality of service requirements over a Differentiated Services Internet architecture. The EMBAC basic idea is to decentralize the admission control decision, by requiring each individual user to probe the network path during flow setup, and by basing the accept/reject decision on the probing traffic statistics measured at the destination. In conformance with the differentiated services framework, routers are oblivious to individual flows and only need to serve data packets with a higher priority than probing traffic. In this paper, we build upon the observation that some form of congestion control of the probing packets queue at each router is a key factor to provide performance effective EMBAC operation. The original contribution of the paper is twofold. First, we provide a thorough investigation, by means of both approximate analytical modeling and extensive simulation, of an EMBAC scheme (denoted in the following EMBAC-PD), in which probing queues congestion control is enforced by means of a probing packet expiration deadline at each router. Second, by means of extensive performance evaluation, we show that EMBAC-PD can provide strict QoS guarantees even in the presence of very light probing overhead (few probing packets per flow setup). Most interesting, EMBAC-PD does not necessarily require long probing phases to accurately estimate the network load subject to statistical fluctuations, but can provide effective operation even in the presence of extremely short probing phase duration (e.g., few hundreds of ms, acceptable for practical applications)
First Annual International Conference on Mobile and Ubiquitous Systems: Networking and Services (MobiQuitous`04)
No full textReal time voice service over IP networks by means of an en-to-end measurement-based call admission control
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Analysis and algorithms: An optimization framework for joint sensor deployment, link scheduling and routing in underwater sensor networks
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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
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
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