1,720,992 research outputs found
Distinct Distances in Three and Higher Dimensions
No full textImproving an old result of Clarkson et al., we show that the number of distinct distances determined by a set P of n points in three-dimensional space is 77=141 " ) = ), for any " > 0. Moreover, there always exists a point p 2 P from which there are at least these many distinct distances to the remaining elements of P . The same result holds for points on the three-dimensional sphere. As a consequence, we obtain analogous results in higher dimensions. Categories and Subject Descriptors F.2.2 [Theory of Computation]: Nonnumerical Algorithms and Problems|geometrical problems and computations Work on this paper by the rst three authors has been supported by a grant from the U.S.-Israeli Binational Science Foundation. Work by Boris Aronov has also been supported by NSF Grants CCR-99-72568 and ITR CCR-00-81964. Work by Janos Pach and Micha Sharir has also been supported by NSF Grants CCR-9732101 and CCR-00-98246. Work by Janos Pach has also been supported by a PSC-CUNY Award, and work by Micha Sharir by a grant from the Israel Science Fund (for a Center of Excellence in Geometric Computing) and by the Hermann Minkowski{ MINERVA Center for Geometry at Tel Aviv University. Work by Gabor Tardos has been supported by Hungarian Science Foundation grants OTKA T029255, OTKA T030059, and AKP 2000-78 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
Drawing Trees, Outerplanar Graphs, Series-Parallel Graphs, and Planar Graphs in Small Area
No full textThe Crossing-Angle Resolution in Graph Drawing
No full textThe crossing angle resolution of a drawing of a graph measures the smallest angle formed by any pair of crossing edges. In this paper we survey some of the most recent results and discuss the current
research agenda on drawings of graphs with good crossing angle resolution
A Note on the Self-similarity of Some Orthogonal Drawings
No full textLarge graphs are difficult to browse and to visually explore. This note adds up evidence that some graph drawing techniques, which produce readable layouts when applied to medium-size graphs, yield self-similar patterns when launched on huge graphs. To prove this, we consider the problem of assessing the self-similarity of graph drawings, and measure the box-counting dimension of the output of three algorithms, each using a different approach for producing orthogonal grid drawings with a reduced number of bends.
Work partially supported by European Commission – Fet Open project COSIN – COevolution and Self-organisation In dynamical Networks – IST-2001-33555, by European Commission – Fet Open project DELIS – Dynamically Evolving Large Scale Information Systems – Contract no 001907, by ldquoProgetto ALINWEB: Algoritmica per Internet e per il Webrdquo, MIUR Programmi di Ricerca Scientifica di Rilevante Interesse Nazionale, and by ldquoThe Multichannel Adaptive Information Systems (MAIS) Projectrdquo, MIUR Fondo per gli Investimenti della Ricerca di Base
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