1,720,996 research outputs found
On K-moduli of quartic threefolds
Get PDFThe family of smooth Fano 3-folds with Picard rank 1 and anticanonical volume 4 consists of quartic 3-folds and of double covers of the 3-dimensional quadric branched along an octic surface. They can all be parametrised as complete intersections of a quadric and a quartic in the weighted projective space P(1,1,1,1,1,2), denoted by X_{2,4} \subset P(1,1,1,1,1,2); all such smooth complete intersections are K-stable. With the aim of investigating the compactification of the moduli space of quartic 3-folds given by K-stability, we exhibit three phenomena: (i) there exist K-polystable complete intersection Fano 3-folds X_{2,2,4} \subset P(1^5,2^2) which deform to quartic 3-folds and are neither quartic 3-folds nor double covers of quadric 3-folds – in other words, the closure of the locus parametrising complete intersections X_{2,4} \subset P(1^5,2) in the K-moduli contains elements that are not of this type; (ii) any quasi-smooth X_{2,2,4} \subset P(1^5,2^2) is K-polystable; (iii) the closure in the K-moduli space of the locus parametrising complete intersections X_{2,2,4} \subset P(1^5,2^2) which are not complete intersections X_{2,4} \subset P(1^5,2) contains only points which correspond to complete intersections X_{2,2,4} \subset P(1^5,2^2)
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Smooth exceptional del Pezzo surfaces
Get PDFFor a Fano variety V with at most Kawamata log terminal (klt) singularities and a finite group
G acting bi-regularly on V , we say that V is G-exceptional (resp., G-weakly-exceptional) if the
log pair (V,∆)
is klt (resp., log canonical) for all G-invariant effective Q-divisors ∆ numerically
equivalent to the anti-canonical divisor of V. Such G-exceptional klt Fano varieties V are
conjectured to lie in finitely many families by Shokurov ([Sho00, Pro01]). The only cases for
which the conjecture is known to hold true are when the dimension of V is one, two, or V is
isomorphic to n-dimensional projective space for some n. For the latter, it can be shown that
G must be primitive—which implies, in particular, that there exist only finitely many such G
(up to conjugation) by a theorem of Jordan ([Pro00]).
Smooth G-weakly-exceptional Fano varieties play an important role in non-rationality
problems in birational geometry. From the work of Demailly (see [CS08, Appendix A]) it
follows that Tian’s αG-invariant for such varieties is no smaller than one, and by a theorem
of Tian such varieties admit G-invariant Kähler-Einstein metrics. Moreover, for a smooth
G-exceptional Fano variety and given any G-invariant Kähler formin the first Chern class, the
Kähler-Ricci iteration converges exponentially fast to the Kähler form associated to a Kähler-
Einsteinmetric in the C∞(V)-topology. The termexceptional is inherited from singularity
theory, to which this study enjoys strong links.
We classify two-dimensional smooth G-exceptional Fano varieties (del Pezzo surfaces)
and provide a partial list of all G-exceptional and G-weakly-exceptional pairs
(S,G), where S
is a smooth del Pezzo surface and G is a finite group of automorphisms of S. Our classification
confirms many conjectures on two-dimensional smooth exceptional Fano varieties
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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