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    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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 Shintani-type formula for Gross--Stark units over function fields

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    Let F be a totally real number field of degree n, and let H be a finite abelian extension of F. Let p denote a prime ideal of F that splits completely in H. Following Brumer and Stark, Tate conjectured the existence of a p-unit u in H whose p-adic absolute values are related in a precise way to the partial zeta-functions of the extension H/F. Gross later refined this conjecture by proposing a formula for the p-adic norm of the element u. Recently, using methods of Shintani, the first author refined the conjecture further by proposing an exact formula for u in the p-adic completion of H. In this article we state and prove a function field analogue of this Shintani-type formula. The role of the totally real field F is played by the function field of a curve over a finite field in which n places have been removed. These places represent the “real places” of F. Our method of proof follows that of Hayes, who proved Gross’s conjecture for function fields using the theory of Drinfeld modules and their associated exponential functions

    Brumer-Stark Units and Explicit Class Field Theory

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    Let FF be a totally real field of degree nn and pp an odd prime. We prove the pp-part of the integral Gross--Stark conjecture for the Brumer--Stark pp-units living in CM abelian extensions of FF. In previous work, the first author showed that such a result implies an exact pp-adic analytic formula for these Brumer--Stark units up to a bounded root of unity error, including a ``real multiplication'' analogue of Shimura's celebrated reciprocity law from the theory of Complex Multiplication. In this paper we show that the Brumer--Stark units, along with n1n-1 other easily described elements (these are simply square roots of certain elements of FF) generate the maximal abelian extension of FF. We therefore obtain an unconditional construction of the maximal abelian extension of any totally real field, albeit one that involves pp-adic integration for infinitely many primes pp. Our method of proof of the integral Gross--Stark conjecture is a generalization of our previous work on the Brumer--Stark conjecture. We apply Ribet's method in the context of group ring valued Hilbert modular forms. A key new construction here is the definition of a Galois module \nabla_{\!\sL} that incorporates an integral version of the Greenberg--Stevens \sL-invariant into the theory of Ritter--Weiss modules. This allows for the reinterpretation of Gross's conjecture as the vanishing of the Fitting ideal of \nabla_{\!\sL}. This vanishing is obtained by constructing a quotient of \nabla_{\!\sL} whose Fitting ideal vanishes using the Galois representations associated to cuspidal Hilbert modular forms..Comment: 70 pages (to appear in Duke Math. J.
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