1,720,963 research outputs found
Electric network and Hirota type -simplex maps
Get PDFBazhanov--Stroganov (4-simplex) maps are set-theoretical solutions to the
4-simplex equation, namely the fourth member of the family of -simplex
equations, which are fundamental equations of mathematical physics. In this
paper, we develop a method for constructing Bazhanov--Stroganov maps as
extensions of tetrahedron maps which are set-theoretical solutions to the
Zamolodchikov tetrahedron (3-simplex) equation. We employ this method to
construct birarional Bazhanov--Stroganov maps which boil down to the famous
electric network and Hirota tetrahedron maps at a certain limit.Comment: 12 pages, 1 figur
Birational solutions to the set-theoretical 4-simplex equation
Get PDFThe 4-simplex equation is a higher-dimensional analogue of Zamolodchikov's
tetrahedron equation and the Yang--Baxter equation which are two of the most
fundamental equations of mathematical physics. In this paper, we introduce a
method for constructing 4-simplex maps, namely solutions to the set-theoretical
4-simplex equation, using Lax matrix refactorisation problems. Employing this
method, we construct 4-simplex maps which at a certain limit give tetrahedron
maps classified by Kashaev, Korepanov and Sergeev. Moreover, we construct a
Kadomtsev--Petviashvili type of 4-simplex map. Finally, we introduce a method
for constructing 4-simplex maps which can be restricted on level sets to
parametric 4-simplex maps using Darboux transformations of integrable PDEs. We
construct a nonlinear Schr\"odinger type parametric 4-simplex map which is the
first parametric 4-simplex map in the literature.Comment: Revised version, published in Physica
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
Anticommutative extension of the Adler map
Get PDFWe construct a noncommutative (Grassmann) extension of the well-known Adler Yang–Baxter map. It satisfies the Yang–Baxter equation, it is reversible and birational. Our extension preserves all the properties of the original map except the involutivity
Darboux transformations, finite reduction groups and related Yang-Baxter maps
No full textIn this paper we construct Yang-Baxter (YB) maps using Darboux matrices which are invariant under the action of finite reduction groups. We present 6-dimensional YB maps corresponding to Darboux transformations for the Nonlinear Schr\"odinger (NLS) equation and the derivative Nonlinear Schr\"odinger (DNLS) equation. These YB maps can be restricted to dimensional YB maps on invariant leaves. The former are completely integrable and they also have applications to a recent theory of maps preserving functions with symmetries \cite{Allan-Pavlos}. We give a dimensional YB-map corresponding to the Darboux transformation for a deformation of the DNLS equation. We also consider vector generalisations of the YB maps corresponding to the NLS and DNLS equation
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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