1,720,960 research outputs found
Critical examination of the life models for electrical insulation under combined stresses in the light of the boundary conditions
No full textThe combined life models for insulating materials and the boundary conditions that must be satisfied for their mathematical correctness are examined. In the case of materials with threshold, these considerations lead to the introduction of a lower limit gradient of electrical aging, Eo, the existence of which is widely acceptable from a physical point of view. In considering models for materials with threshold, the existence of a thermal threshold, which allows a new general definition of such materials to be forward, is pointed out. Models for materials with threshold in which the limit gradient Eo has been introduced are examined and their mathematical correctness verified. The existence of a threshold curve, and thus of infinite electrothermal threshold couples, is emphasized
A General Multi-stress Life Model for Insulating Materials with or without Evidence for Threshholds
No full textIn this paper a general life model, valid for any type of insulating materials, with or without evidence of an electrical threshold at room temperature, is proposed. First of all, the old definition of threshold or no-threshold materials is changed and the behavior of materials is considered, as a threshold or as a no-threshold material, according to the value of applied stresses. The electrical gradient-temperature graph is examined, showing the relationships between electrical and thermal thresholds. The various life models for electrical and thermal stress used by researchers are examined and discussed; the old combined-stress life model for threshold materials is improved by adding to the denominator a cross term which gives rise to a threshold line which is curved instead of straight. Since for no-threshold materials the denominator should be equal to 1, this is raised to an exponent β, a function of the ratios between the applied stresses and thresholds, which becomes 0 when the stresses are higher than the thresholds (no-threshold behavior) and is, instead, > 0 if at least one of the stresses is lower than the corresponding threshold (threshold behavior). In such a way, the improved model assumes general validity. Application of the model is outlined and compared with experimental data obtained for several insulating materials. © 1993 IEE
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
