1,720,977 research outputs found
Frugal Methods for the Independent Set and Graph Coloring Problems.
No full textWe consider two classical hard graph problems: finding the maximum independent set of vertices, and coloring the vertices with fewest colors possible. We are interested in frugal algorithms for these problems, ones that use limited amount of computing capabilities. Such algorithms yield approximate, rather than exact, solutions, and are valued according to their performance guarantee, which is the maximum factor that approximate solutions can differ from optimal ones. We are primarily interested in two classes of frugal algorithms: polynomial-time, and on-line algorithms. We present several polynomial-time algorithms for obtaining large approximations in graphs containing large independent sets, and use them to improve the best performance guarantees known for both problems. We show how nearly all effective algorithms for these problems fall into yet another category of frugal algorithms, based on removing subgraphs, and obtain tight lower bounds on their performance. For on-line graph coloring, we give strong lower bounds for both deterministic and randomized algorithms, that hold even if the models are weakened in several ways, and improve the best performance guarantee known for randomized on-line coloring. Finally, we prove simple tight bounds on two interpretations of the on-line independent set problem and some of its variations.Technical report DCS-TR-28
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
A Local Broadcast Layer for the SINR Network Model
No full textWe present the first algorithm that implements an abstract MAC (absMAC) layer in the Signal-to-Interference-plus-Noise-Ratio (SINR) wireless network model. We first prove that efficient SINR implementations are not possible for the standard absMAC specification. We modify that specification to an "approximate" version that better suits the SINR model. We give an efficient algorithm to implement the modified specification, and use it to derive efficient algorithms for higher-level problems of global broadcast and consensus.
In particular, we show that the absMAC progress property has no efficient implementation in terms of the SINR strong connectivity graph G[subscript 1-ε], which contains edges between nodes of distance at most (1-ε) times the transmission range, where ε>0 is a small constant that can be chosen by the user. This progress property bounds the time until a node is guaranteed to receive some message when at least one of its neighbors is transmitting. To overcome this limitation, we introduce the slightly weaker notion of approximate progress into the absMAC specification. We provide a fast implementation of the modified specification, based on decomposing the algorithm of [10] into local and global parts. We analyze our algorithm in terms of local parameters such as node degrees, rather than global parameters such as the overall number of nodes. A key contribution is our demonstration that such a local analysis is possible even in the presence of global interference.
Our absMAC algorithm leads to several new, efficient algorithms for solving higher-level problems in the SINR model. Namely, by combining our algorithm with high-level algorithms from [26], we obtain an improved (compared to [10]) algorithm for global single-message broadcast in the SINR model, and the first efficient algorithm for multi-message broadcast in that model. We also derive the first efficient algorithm for network-wide consensus, using a result of [32]. This work demonstrates that one can develop efficient algorithms for solving high-level problems in the SINR model, using graph-based algorithms over a local broadcast abstraction layer that hides the technicalities of the SINR platform such as global interference. Our algorithms do not require bounds on the network size, nor the ability to measure signal strength, nor carrier sensing, nor synchronous wakeup.United States. Air Force Office of Scientific Research (Contract FA9550-13-1-0042)National Science Foundation (U.S.) (Award 0939370-CCF)National Science Foundation (U.S.) (Award CCF-1217506)National Science Foundation (U.S.) (Award CCF-AF-0937274
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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