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Restricted matching in graphs of small genus
No full textAbstractA graph G with at least 2n+2 vertices is said to be n-extendable if every set of n disjoint edges in G extends to (i.e., is a subset of) a perfect matching. More generally, a graph is said to have property E(m,n) if, for every matching M of size m and every matching N of size n in G such that M∩N=0̸, there is a perfect matching F in G such that M⊆F, but F∩N=0̸. G is said to have property E(0,0) if it has a perfect matching. The study of the properties E(m,n) is referred to as the study of restricted matching extension.In [M. Porteous, R. Aldred, Matching extensions with prescribed and forbidden edges, Australas. J. Combin. 13 (1996) 163–174; M. Porteous, Generalizing matching extensions, M.A. Thesis, University of Otago, 1995; A. McGregor-Macdonald, The E(m,n) property, M.Sc. Thesis, University of Otago, 2000], Porteous and Aldred, Porteous and McGregor-Macdonald, respectively, studied the possible implications among the properties E(m,n) for various values of m and n. In an earlier paper [R.E.L. Aldred, Michael D. Plummer, On restricted matching extension in planar graphs, in: 17th British Combinatorial Conference (Canterbury 1999), Discrete Math. 231 (2001) 73–79], the present authors completely determined which of the various properties E(m,n) always hold, sometimes hold and never hold for graphs embedded in the plane. In the present paper, we do the same for embeddings in the projective plane, the torus and the Klein bottle
Corrigendum to "Graphs and digraphs with all 2--factors isomorphic" [J. of Comb. Th. Ser. B 92, (2) (2004) 395--404]
No full textWe point out several errors in our article [M. Abreu, R.E.L. Aldred, M. Funk, B. Jackson, D. Labbate, J. Sheehan, Graphs and digraphs with all 2-factor isomorphic, J. Combin. Theory Ser. B 92 (2004) 395–404] which were caused by our misquoting of a theorem of C. Thomassen. We also describe how the correct statement of Thomassen’s theorem, together with another of his theorems, can be used to obtain weaker results than those incorrectly stated in our original article
On the restricted matching extension of graphs on the torus and the Klein bottle
No full textAbstractAldred and Plummer proved that every 6-connected even graph minimally embedded on the torus or the Klein bottle is E(1,n)(n≤3) and E(0,n)(n≤5) [R.E.L. Aldred, M.D. Plummer, Restricted matching in graphs of small genus, Discrete Math. 308 (2008) 5907–5921]. In this paper, we can remove the upper bounds on n by showing that every even 6-regular graph G embedded on the torus or the Klein bottle has property E(1,n−1) and E(0,n) for arbitrary n≤|V(G)|2−1
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
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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