1,354,798 research outputs found
Wijs omgaan met wantrouwen
No full text‘Fake news’, ‘virus- en 5G-wappies’: complotdenken kan gemakkelijk worden gediskwalificeerd. Maar wantrouwen van informatiebronnen is op zich niet gek. Wetenschappers en politiemensen doen dat ook. Cruciaal voor politiemensen is om wijs met wantrouwen om te gaan: het eigen wantrouwen en dat van een ander, burger of collega. Deze column gaat in op valkuilen en ontwikkelmogelijkheden voor de Nederlandse politie
Hybrid and Organic Functional Materials: A First-Principles Study
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159050.pdf (Publisher’s version ) (Open Access)RU Radboud Universiteit, 18 oktober 2016Promotor : Groot, R.A. de Co-promotor : Wijs, G.A. deVI, 157 p
Treatise on magnetocaloric MnFe(Si,P) compounds : a first-principles study
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160398.pdf (Publisher’s version ) (Open Access)RU Radboud Universiteit, 10 oktober 2016Promotor : Groot, R.A. de Co-promotor : Wijs, G.A. deIX, 113 p
Complex hydrides for hydrogen storage : a first-principles study
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106979.pdf (Publisher’s version ) (Open Access)Radboud Universiteit Nijmegen, 18 juni 2013Promotor : Groot, R.A. de Co-promotores : Wijs, G.A. de, Brocks, G.107 p
An expanded de Wijs model for multifractal analysis of mineral production data
No full textHydrothermal ore deposits form by enriching elements and minerals from background values to very high concentrations in small volumes of the crust. The de Wijs model provides a simple and widely used mathematical description of this process; however, it does not account for the increase in density which generally attends the formation of high specific gravity minerals in many mineral deposits. We present an expanded version of the de Wijs model to investigate the distribution of ore tonnage as well as grade. The expanded model generates a log–normal relationship between ore tonnage and grade. Continuous
multifractal analysis of results from the new model using
the method of moments technique predicts that ore grades
are multifractal (as in the original de Wijs model) but that
ore tonnage values are not multifractal. Production data
from vein-hosted gold deposits in the Archaean Zimbabwe
craton display the log–normal relationship between ore
tonnage and grade, the multifractal nature of ore grade, and
the nonmultifractal nature of ore tonnage, which are
generated in the expanded de Wijs model
First-order intrinsic autoregressions and the de Wijs process
No full textWe discuss intrinsic autoregressions for a first-order neighbourhood on a two-dimensional rectangular lattice and give an exact formula for the variogram that extends known results to the asymmetric case. We obtain a corresponding asymptotic expansion that is more accurate and more general than previous ones and use this to derive the de Wijs variogram under appropriate averaging, a result that can be interpreted as a two-dimensional spatial analogue of Brownian motion obtained as the limit of a random walk in one dimension. This provides a bridge between geostatistics, where the de Wijs process was once the most popular formulation, and Markov random fields, and also explains why statistical analysis using intrinsic autoregressions is usually robust to changes of scale. We briefly describe corresponding calculations in the frequency domain, including limiting results for higher-order autoregressions. The paper closes with some practical considerations, including applications to irregularly-spaced data. Copyright 2005, Oxford University Press.
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
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