1,721,299 research outputs found
On collineation groups generated by Bol reflections
No full textIn this paper we take up an approach by A. Barlotti and K. Strambach and investigate the connection between geometric transformation groups (generated by Bol reflections) and algebraic invariants in the case of Bol 3-nets
(Anti-)hypercomplex structures and 3-webs on a manifold
No full textPreprint n. 38/03 Dip. Mat. Univ. di Roma "La Sapienza"
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
Lower bounds on the minimum distance in Hermitian one-point differential codes
No full textIn \cite{KoNa} the authors computed the Weierstrass gap sequence of the Hermitian function field \mathbb{F}_{q^2}(\HC) at any place of degree , and obtained an explicit formula of the Matthews-Michel lower bound on the minimum distance in the associated differential Hermitian code where the divisor is, as usual, the sum of all but one
-degree -rational places of \mathbb{F}_{q^2}(\HC) and is a positive integer. For plenty of values of depending on , this provided improvements on the designed minimum distance of . Further improvements from were obtained in \cite{KoNa} relying on algebraic geometry. Here slightly weaker improvements are obtained from with the usual function-field method depending on linear series, Riemann-Roch theorem and Weierstrass semigroups. We also survey the known results on this subject
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
Hermitian codes from higher degree places
No full textMatthews and Michel \cite{Michel} investigated the minimum distances of certain algebraic-geometry codes arising from a higher degree place . In terms of the Weierstrass gap sequence at , they proved a bound that gives an improvement on the designed minimum distance. In this paper, we consider those of such codes which are constructed from the Hermitian function field \mathbb F_{q^2}(\HC). We determine the Weierstrass gap sequence where is a degree place of \mathbb F_{q^2}(\HC), and compute the Matthews and Michel bound with the corresponding improvement. We show more improvements using a different approach based on geometry. We also compare our results with the true values of the minimum distances of Hermitian -point codes, as well as with estimates due to Xing and Chen \cite{XC}
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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