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A general weight function for inclined cracks at sharp V-notches
No full textA general method for evaluating the Stress Intensity Factors of an inclined edge crack originated at the tip of a sharp V-notch in a semiplane is presented. An analytical Weight Function with a matrix structure was derived by extending a method developed for an inclined edge crack in an unnotched semi-plane. The effects of the principal geometrical parameters governing the problem were studied through a parametric finite element analysis, carried out for different reference loading conditions. The Weight Function can be used to produce efficient and accurate evaluations of the stress intensity factors for cracks with inclination angle in the range -72 degrees, +72 degrees emanating from V-notches with opening angle in the range from 18 degrees to 144 degrees. For a crack length up to the 10% of the characteristic notch dimension, the maximum estimated error of the Stress Intensity Factor is lower than 2% (typical errors less than 1%) in the whole ranges of the angular parameters. The capability of the proposed method to analyse cracked notches in finite-size bodies was also considered. The agreement between the results with those obtained by accurate Finite Element solutions suggests that the proposed Weight Function can be used as a general tool for evaluating the Fracture Mechanics parameters of a short crack at any V-notch tip. (c) 2006 Elsevier Ltd. All rights reserved
AUTOIMMUNITY IN MULTIPLE SCLEROSIS: STUDY A WIDE SPECTRUM OF AUTOANTIBODIES
No full textWe have followed up 63 pregnancies in women with autoimmune thrombocytopenic purpura (ATP). Of these, 15 were previously splenectomized. The characteristics of the sample can be summed up as follows: average age 27 years (17-41); platelets at the beginning of pregnancy, mean 129.5 x 10(9)/l (range 16-488); platelets at delivery, mean 133 x 10(9)/l (range 8-477); PA-IgG at delivery, mean 320 ng IgG/10(7) platelets (range 10-1000); SPB-IgG at delivery, mean 262 ng IgG/10(7) platelets (range 10-1000). There were 30 spontaneous deliveries and 33 cesarean sections. Forty-two newborns had a platelet count within the normal range while nine had a platelet count less than or equal to 150 x 10(9)/l, while six had less than or equal to 100 x 10(9)/l and a further six less than or equal to 50 x 10(9)/l. The aim of this study is the evaluation of maternal risk and of possible feto-neonatal thrombocytopenia at birth. In this regard, the following parameters were considered: previous maternal splenectomy; the platelet count at the beginning of pregnancy; the platelet count and the titres of PA-IgG and SPB-IgG at delivery. Preliminary statistical evaluation of these parameters enabled us to identify a risk score. From this it was possible to obtain an optimum management of the final stage of pregnancy regarding the therapeutic approach and the timing of delivery
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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