1,720,958 research outputs found
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
IMPROVING SEMI-JOIN PROGRAMS FOR DISTRIBUTED QUERY PROCESSING.
No full textThe problem of optimal query processing in distributed database systems was shown to be NP-hard. This means that heuristic algorithms are necessary to solve the query processing problem. Algorithms are described to improve the solutions generated by heuristics. Four properties are identified which optimal semi-join programs for processing tree queries have to satisfy. A semi-join program is represented by an execution graph which specifies the order and the identities of the semi-joins to be executed. Given a semi-join program, we can therefore apply these properties to check its optimality. If it does not satisfy these optimality properties, the associated improvement algorithms can be applied to improve this program. No assumptions have been made about the relation size and the selectivity of the semi-joins.link_to_subscribed_fulltex
OPTIMAL ALGORITHM FOR PROCESSING DISTRIBUTED STAR QUERIES.
No full textThe problem of optimal query processing in distributed database systems was shown to be NP-hard. However, for a special type of query called star queries, a polynomial optimal algorithm using semijoin tactics has been developed. An execution graph is introduced to represent the semijoin programs associated with the distributed processing of the queries. Optimality properties of semijoin programs for star queries are then identified and used to derive the optimal semijoin program. It is shown that the optimal semijoin program can be found from serial semijoin strategies, defined as serial semijoin programs that include each semijoin associated with the query exactly once. By making certain assumptions on the file sizes and the semijoin selectivities, the optimal semijoin program can be obtained from these strategies in polynomial time.link_to_subscribed_fulltex
DERIVING OPTIMAL SEMI-JOIN PROGRAMS FOR DISTRIBUTED QUERY PROCESSING.
No full textlink_to_subscribed_fulltex
IMPROVEMENT ALGORITHMS FOR SEMIJOIN QUERY PROCESSING PROGRAMS IN DISTRIBUTED DATABASE SYSTEMS.
No full textThe problem of optimal query processing in distributed database system has been shown to be NP-hard. This means that heuristic algorithms are necessary to solve the query processing problem. Algorithms to improve the solutions generated by heuristics are described. Four properties have been identified that optimal semijoin programs for processing tree queries have to satisfy. A semijoin program is represented by an execution graph which specifies the order and the identities of the semijoins to be executed. Given a semijoin program, one can therefore apply these properties to check its optimality. If it does not satisfy these optimality properties, the associated improvement algorithms can be applied to improve this program. No assumptions have been made about the relation size and the selectivity of the semijoins.link_to_subscribed_fulltex
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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