1,721,041 research outputs found
An improved procedure for 2D unstructured Delaunay mesh generation
No full textThis paper presents a procedure for the discretization of 2D domains using a Delaunay triangulation. Improvements over existing similar methods are introduced, proposing in particular a multi-constraint insertion algorithm, very effective in the presence of highly irregular domains, and the topological-structure used together with its primitives. The method obtained requires limited input and can be applied to a wide class of-domains. Quadrilateral subdivisions with a control of the aspect ratio of the generated elements can a] so be reached. Further it is suitable for evolutionary problems, Which require continuous updating of the, discretization. Presented applications and comparisons with other discretization methods demonstrate the effectiveness of the procedure
On the location of concentration points for singularly perturbed elliptic equations
No full textBy exploiting a variational identity of Pohozaev-Pucci-Serrin
type for solutions of class C1, we get some necessary conditions for
locating the peak-points of a class of singularly perturbed quasilinear
elliptic problems in divergence form. More precisely, we show that the
points where the concentration occurs, in general, must belong to what
we call the set of weak-concentration points. Finally, in the semilinear
case, we provide a new necessary condition which involves the Clarke
subdifferential of the ground-state function
On the location of spikes for the Schrodinger equation with electromagnetic field
No full textWe consider the standing wave solutions of the three dimensional semilinear Schrodinger
equation with competing potential functions V and K and under the action of an external
electromagnetic field B. We establish some necessary conditions for a sequence of such
solutions to concentrate, in two different senses, around a given point. In the particular
but important case of nonlinearities of power type, the spikes locate at the critical points
of a smooth ground energy map independent of B
La progettazione acustica degli edifici. Pianificazione del territorio, clima acustico e tutela degli spazi abitativi
No full text
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
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