1,721,183 research outputs found
Investigation of Quasi-Periodic Solutions in Nonlinear Oscillators Featuring Internal Resonance
No full textQuasi-periodic solutions can arise in assemblies of nonlinear oscillators as a consequence of Neimark--Sacker (NS) bifurcations. In this chapter, we investigate analytically and numerically the system of two coupled oscillators in two different settings featuring 1:2 and 1:3 internal resonances, respectively. More specifically, in the former case, the locus of NS points is obtained analytically, and its variation with respect to the system parameters is highlighted. In the latter case, on the contrary, the NS boundary curve is investigated numerically. In both cases, the results allow predicting the appearance of quasi-periodic solutions
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
A rod model with flexible thin-walled cross-section : Application to the folding of tape springs in 3D
No full textCe travail a pour cadre une collaboration entre le LMA et Thales Alenia Space. Nous nous intéressons au comportement des structures flexibles et plus particulièrement des mètres rubans qui ont la particularité de pouvoir, grâce à l’aplatissement de la section, s’enrouler ou développer des pliages localisés. Une première thèse a permis d’une part la mise au point d’un nouveau type de mètre ruban au déroulement maîtrisable thermiquement et d’autre part le développement d’un modèle plan de poutre à section flexible. Dans le travail de thèse présenté ici, nous proposons une version étendue de ce modèle adaptée à la simulation du comportement dynamique tridimensionnel des mètres rubans en grands déplacements et en grandes rotations. Ce modèle est dérivé de la théorie des coques et repose sur l’introduction d’hypothèses cinématiques et sthéniques adaptées. La déformation de la section est caractérisée par celle de sa ligne moyenne qui peut se déformer dans son plan par flexion et torsion mais non par extension, ainsi que hors de son plan par gauchissement de torsion. Les fortes variations de forme de la section dans son plan peuvent alors être décrites par une cinématique de type Elastica, tandis qu’une cinématique de type Vlassov est utilisée pour définir le gauchissement dans le repère local attaché à la section. Le modèle unidimensionnel est obtenu par intégration sur la section des expressions de la théorie des coques, une approche énergétique permet ensuite de formuler le problème associé qui est résolu grâce au logiciel de modélisation par éléments finis COMSOL.This work was carried out within the framework of a collaboration between the LMA and Thales Alenia Space. We focus on the behaviour of flexible structures and more specifically of tape springs, whose particularity lies in their capacity to coil up or to form localized folds through the flattening of their cross-section. A first thesis led to the development of a new type of tape spring whose uncoiling is controlled thermically on one hand and of a planar rod model with a flexible thin-walled cross-section on the other hand. In this thesis, we offer an extended version of this model dedicated to the simulation of three-dimensional dynamic behavior of tape springs in large displacements and large rotations. This model is derived from shell theory and is based on the introduction of adapted kinematic and sthenic hypotheses. The deformation of the cross-section is characterized by that of its average line which can deform in its own plane by flexion and twisting but not by extension, as well as out of its plane through torsional warping. The large changes of the cross-section shape in its plane can then be described by an Elastica kinematics, whereas a Vlassov kinematics is used to define the warping in the local frame attached to the section. The unidimensionnal model is obtained by integration over the cross-section of the expressions of the shell theory, an energetic approach then allows to express the associated problem which is solved thanks to the finite element modeling software COMSOL
- …
