1,720,962 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
A Comparison of Parallel and Sequential Niching Methods
No full textNiching methods extend genetic algorithms to domains that require the location of multiple solutions. This study examines and compares four niching methods --- sharing, crowding, sequential niching, and parallel hillclimbing. It focuses on the differences between parallel and sequential niching. The niching methods undergo rigorous testing on optimization and classification problems of increasing difficulty. A niching-based technique is introduced that extends genetic algorithms to classification problems. 1 INTRODUCTION Niching methods (Mahfoud, 1995) promote the formation and maintenance of stable subpopulations in genetic algorithms (GAs), allowing GAs to extend their problem-solving power to complex domains. This study examines four niching methods and compares their performances on problems in both classification and multimodal function optimization. The problems cover a wide range of difficulty levels. Classification problems are solved via a new niching-based technique. Paral..
Crossover Interactions among Niches
No full textThis paper explores the distribution of population elements among niches arising under deterministic crowding. Crossover interactions among niches are observed, isolated, and explained. Ideal behavior is compared with actual behavior on a variety of multimodal optimization problems, including a multimodal deceptive problem. I. Introduction Niching methods in genetic algorithms (GAs) strive to locate and maintain stable subpopulations or niches, within a single population. While sharing techniques [1, 2] have proven effective, crowding methods [3, 4] are also promising. Previously, little was known about the expected behavior of crowding methods. In this study, crowding turns out to behave far differently than sharing. Intrinsic properties of crowding are uncovered via controlled experimentation and intuitive modelling. Specifically, we concentrate upon the distributions arising from the combination of crossover and replacement selection in deterministic crowding. This combination ..
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