1,720,970 research outputs found
Parallel Computational Magneto-Fluid Dynamics
No full textThis report intends to highlight the various parallel tools, the sophisticated numerical backbones they employ, and the results obtained so far. Bimonthly meetings were held to stimulate collaboration and to exchange experiences between the eight groups, which are the MHD group of Prof. Dr. J.P. Goedbloed at the FOM-Institute for Plasma Physics `Rijnhuizen' in Nieuwegein (FOM), the Numerical Analysis group of Prof. Dr. H.A. van der Vorst at the Mathematics Institute of Utrecht University (SWON), the group of Prof. Dr. A.G. Hearn at the Astronomical Institute of Utrecht University (ASTRON), the group of Dr. Ir. H.J.J. te Riele at the CWI in Amsterdam (SWON), the Computational Physics group of Prof. Dr. Ir. W. Lourens at Utrecht University (FOM), the group of Dr. J.P. van Leeuwen at the Institute for Marine and Atmospheric Research Utrecht (MFO), the group of Physical Informatics of Prof. Dr. Ir. H.J. Sips at Delft University of Technology (SION), and the group of Prof. Dr. U. Hansen at the Geodynamics Research Institute of Utrecht University (GOA). We provide an update on our research goals, the present list of participants, and an outlook on short-term continuation in Sec. 1. A description of each subproject follows in Sec. 2-4. The Versatile Advection Code has been extended with a great variety of implicit and semi-implicit time integration schemes and scales nicely in High Performance Fortran (Sec. 2.2.1). The implicit code makes use of a succesful preconditioner for the iterative schemes (Sec. 2.2.5). A data parallel code for simulating magnetized loop dynamics running on all architectures has excellent scaling properties on the Cray T3E and the CM-5 (Sec. 2.2.2). Generalized eigenvalue problems can be solved in parallel (Sec. 2.2.4). The Minimal Residual -- Predicto..
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
Two-dimensional equilibrium in coronal magnetostatic flux tubes: An accurate equilibrium solver.
No full textTo study linearized magnetohydrodynamic (MHD) waves, continuous spectra, and instabilities in coronal magnetic flux tubes that are anchored in dense chromospheric and photospheric regions, a two-dimensional numerical code, called PARIS, has been developed. PARIS solves the pertinent nonlinear Grad-Shafranov type, partial differential equation for the magnetic flux on a flux coordinate grid. Both a straight field line coordinate system and an orthogonal flux coordinate system are exploited. Isoparametric bicubic Hermite finite elements have been adopted to solve the Grad-Shafranov-like equation. These elements allow for a continuous representation of the Bur and the gradient of the flux throughout the tube and can be aligned conveniently along the boundary of the tube. These properties are important to obtain an accurate representation of the solution on flux coordinate grids. An analytical test case is used to show that accurate solutions have been obtained, even for a small number of grid points. The equilibria calculated by PARIS are used to study the continuous spectra of two-dimensional magnetic flux tubes. One illustrative example is given here; extensive results are presented elsewhere (A.J.C. Belien, S. Poedts and J.P. Goedbloed, Astron. Astrophys. 322 (1997) 995). The equilibria obtained by PARIS are also well suited to calculate the stability and the normal mode MHD spectrum. (C) 1997 Elsevier Science B.V
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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