1,721,142 research outputs found
4-blocked Hadamard 3-designs
No full textThe important role of Hadamard designs for applications in several fields has been long established. A considerable problem of finite geometry is to determine the configuration of the minimum number of points that block a design, i.e. the shape of a minimum set of points which have at least one point in common with any block. In this paper we del with Hadamard 3-designs blocked by only four points
Perfect Octagon Quadrangle Systems with upper C(4)-systems and a large spectrum
No full textAn octagon quadrangle is the graph consisting of an 8-cycle (x1,x2,...,x8) with two additional chords: the edges {x1,x4} and {x5,x8}. An octagon quadrangle system of order v and index λ (OQS) is a pair (X,H), where X is a finite set of v vertices and H is a collection of edge disjoint octagon quadrangles (called blocks) which partition the edge set of $\lambda λKv defined on X. An octagon quadrangle system Σ=(X,H) of order v and index λ is said to be upper C4-perfect if the collection of all of the upper 4-cycles contained in the octagon quadrangles form a μ-fold 4-cycle system of order v; it is said to be upper strongly perfect if the collection of all of the upper 4-cycles contained in the octagon quadrangles form a μ-fold 4-cycle system of order v and also the collection of all of the outside 8-cycles contained in the octagon quadrangles form a ρ-fold 8-cycle system of order v. In this paper, the authors determine the spectrum for these systems, in the case that it is the largest possible
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
Perfect octagon quadrangle systems
No full textAn octagon quadrangle is the graph consisting of an 8-cycle (x1,...,x8) with two additional chords: the edges {x1,x4},{x1,x4} and {x5,x8}. An octagon quadrangle system (OQS) of order v and index λ is a pair (X,B), where X is a finite set of v vertices and B is a collection of edge disjoint octagon quadrangles, which partitions the edge set of λK(v) defined on X. An OQS Σ=(X,B) of order v and index λ is strongly perfect if the collection of all the inside 4-cycles contained in the octagon quadrangles form a μ-fold 4-cycle system of order v, and the collection of all the outside 8-cycle quadrangles contained in the octagon quadrangles form a ρ-fold 8-cycle system of order v. More generally, C4-perfect OQSs and C8-perfect OQSs are also defined. In this paper, following the ideas of polygon systems introduced by L. Gionfriddo in her papers [Bull. Inst. Combin. Appl. 48 (2006), 73-81; MR2259705; Discrete Math. 308 (2008), no. 2-3, 231-241; MR2378021 (2008k:05167); Australas. J. Combin. 36 (2006), 167-176; MR2262617 (2007e:05025); Discrete Math. 309 (2009), no. 2, 505-512; MR2478727 (2010f:05122)], we determine completely the spectrum of strongly perfect OQSs, C4-perfect OQSs and C8-perfect OQSs, having the minimum possible value for their indices
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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