1,721,023 research outputs found
3D modelling of electrical anisotropy from electromagnetic array data: hypothesis testing for different upper mantle conduction mechanisms
No full textUpper mantle electrical conductivities provide, besides seismic velocities or thermal diffusivities, another source of information on upper mantle structure and composition. We present the results of a long-period magnetotelluric dataset, consisting of 64 sites covering an area of 300 kin x 400 km in central Germany, mapping electrical conductivities at the base of the lithosphere. To seperate the effect of crustal and upper mantle structures, we interprete the obtained dataset by 31) conductivity modelling. We observe high conductivities and anisotropies at asthenospheric upper mantle depth, with main bulk conductivities of similar to 1-2 S/m in west-east and similar to 4 x 10(-3) S/m in north-south direction, differing by about two orders of magnitude. In comparing with results from laboratory measurements on electrical conductivites for various conduction mechanisms we are able to confine the conduction mechanisms possibly dominating at these depths. With melt volume fractions of 1% only partial melt can be excluded as origin of the high upper mantle conductivities. Instead conductivity enhancement due to hydrogen diffusion along the olivine [100]-axis is favoured as the dominant conduction mechanism at the base of the lithosphere. (c) 2004 Elsevier B.V. All rights reserved
Self-designing networks and structural influences on safety: Developing a theory on the relation between organizational design and safety in temporary organizations that operate in a dynamic environment
Full text linkContains fulltext :
178382.pdf (Publisher’s version ) (Open Access)Delft University of Technology, 01 juni 2017Promotores : Ale, B.J.M., Kramer, E.H.213 p
Safety management within Task Force Uruzgan: A report of working with Unmanned Aerial Vehicles
No full textIn this paper we present a conceptualization of safety management that is based on the cybernetic concepts of “controllability” and “control capacity”. In particular, we explore what this conceptualization means for safety management of the Dutch Army’s UAV unit that was part of Task Force Uruzgan (TFU) in the years 2006–2007 and 2008–2009. In this research we applied a qualitative research strategy. We conducted 20 interviews, 13 with employees of the UAV unit and 7 with key TFU-partners with whom the unit had to cooperate. We analyzed the interviews by means of the concepts developed in the theoretical framework. By going back and forth between theory and practice, we show that it was rather problematic for the unit to develop controllability and operate safely. We conclude with a reflection on a safety management strategy for this particular unit and the relevance of our conceptualization for other organizations.Values and TechnologyTechnology, Policy and Managemen
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
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
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
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