1,720,997 research outputs found
Cartographic blandscapes and the new noise: finding the good view in a topographical mashup
No full textShould we expect web map service (WMS) applications to present a faithful description of the landscape? The number of providers continues to grow and concerns about their cartographic quality continue to be raised, generating debate on whether such maps are fit for purpose. This paper explores why cartographers consider the design of these maps to fall short. It suggests how judgments and expectations are drawn from cartographic communication theory and state topographic map design. The paper then proceeds to discuss the meaning of cartographic quality in an age of democratized mappin
Geospatial Technologies in Archaeology
No full textThis chapter describes the application of geospatial technologies in archaeology and explains how they present new ways of understanding and visualizing the past. It examines the value of using key technologies of GIS and remote sensing (including Lidar), and appraises the contribution that 3D models make to the interpretation of archaeological sites for researchers and wider audiences. The limitations of geospatial technologies are discussed, which includes a critical assessment of the assumed objectivity of geospatial data and their role in constructing archaeological ideas
Centre manifold reduction of laser equations with transverse effects: an approach based on modal expansion
No full textCentre Manifold theory is a valuable method for analysing and simplifying partial differential equations that appear in the study of transverse effects in nonlinear optics. In this paper we analyse its application to the Maxwell-Bloch equations for lasers with spherical mirrors and finite size pumps. By taking advantage of the expansion in cavity modes, we successfully compare reduced models with the original one for broad ranges of the parameters
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Feasibility of controlling complex dynamics in multi transverse mode lasers
No full textWe show that a Periodic Proportional Feedback (PPF) method can be successfully applied to the multi-transverse mode laser. We have simulated the laser by integrating the Maxwell-Bloch equations with the electric field projected onto the empty cavity Gauss-Laguerre modes. By applying the PPF technique to chaotic dynamics of low dimension density, we can control periodic orbits which differ only slightly from the unstable periodic orbits of the system, via modulation of the cavity losses and pump parameters, both for the cylindrically symmetric laser and for the case where the symmetry is removed. Our results show that although various periodic orbits can be controlled temporally, pattern selection (i.e. spatio-temporal control) needs more elaborate techniques
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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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