1,720,960 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Théorie du strain hardening dans les polymères vitreux
No full textThe stress-strain curve of a glassy polymer can be divided into 4 different regimes. First the linear elastic regime, where stress linearly increases with strain; then yield at strain values of a few percents, characterised by a maximum in the stress-strain curve of order tens of MPa; the strain softening regime follows, defined by a decrease of stress of a few tens of MPa before reaching a plateau. Finally, some polymers exhibit the strain hardening regime, where stress increases again with strain at high strain values. This mechanical behaviour of glassy polymers is still not described within a unified theory nowadays, in particular the strain hardening regime whose origin is the subject of intense research. From an industrial point of view, strain hardening is of crucial importance because it provides materials with high mechanical properties, especially a high resistance against crack propagation. The PFVD model, developed by Long and co-workers, aims at describing the physical phenomena (at a mesoscopic scale xi = 3-5 nm) at the origin of mechanical and physical properties of apolar amorphous glassy polymers close to Tg. This model has demonstrated its relevance by its ability to reproduce several important properties of glassy polymers such as Tg shifts in thin polymer films, the asymmetry between ageing and rejuvenation, an accurate stress-induced acceleration of the dynamics and plastic properties up to the onset of strain hardening. The PhD work presented in the current manuscript consists in extending the development of the PFVD model in order to better describe the strain hardening mechanism and to validate the model's ability to reproduce additional striking features of glassy polymers. The fundamental idea of the model is that there is a distribution of relaxation times within the polymer at the scale xi : very fast regions coexist and interact with very long ones. In the model, deviatoric stress decreases the free energy barriers for alpha-relaxation at the scale xi : the system, initially composed of very long relaxation times compared to the mechanical timescale, can flow when it is being deformed. Deformation of a polymer generates monomer bonds orientation. The assumption of our model is that this orientation leads to an increase of free energy barriers for alpha-relaxation at the scale xi, which induces strain hardening. An order parameter of tensorial nature has been introduced and quantifies the average orientation of monomer bonds at that scale. The dynamical evolution of that order parameter has been derived. The influence of orientation on local dynamics occurs via a scalar invariant built from the orientational order parameter. The extensions brought to the PFVD model in the framework of this PhD thesis allow to obtain stress-strain curves which are consistent with experimental ones. The dependence of the hardening modulus on temperature and strain rate, the evolution of the relaxation times distribution and the average monomers orientation are also consistent with experimental data. The Bauschinger effect is also reproduced : the mechanical behaviour during successive uniaxial mechanical tests is consistent with that observed experimentally. When heated up, a prestrained polymeric material releases stored elastic energy as heat. When the material has been prestrained up to the strain hardening regime, experimental DSC ramps show the presence of an exothermic peak above Tg which increases with prestrain. The model is able to reproduce qualitatively this phenomenon.Lorsqu'il est déformé, un polymère vitreux présente un comportement mécanique caractéristique qu'il est possible de diviser en 4 régimes différents sur sa courbe contrainte-déformation. Il y a tout d'abord le régime élastique linéaire, où la contrainte augmente linéairement avec la déformation; puis le yield à une déformation de quelques pourcents, caractérisé par un maximum dans la courbe contrainte-déformation de l'ordre de 100 MPa; vient ensuite le strain softening, au cours duquel la contrainte diminue de quelques dizaines de MPa avant d'atteindre un plateau. Enfin, certains polymères présentent de nouveau une augmentation de la contrainte : ce régime est appelé strain hardening. Ce comportement mécanique des polymères vitreux n'est aujourd'hui toujours pas décrit par une théorie physique unifiée, en particulier le régime de strain hardening dont l'origine fait encore l'objet de nombreuses controverses. Or, d'un point de vue industriel, le strain hardening est d'une importance capitale car il permet d'obtenir des matériaux à hautes performances mécaniques, telles que notamment une grande résistance à l'impact et une contrainte à la rupture élevée. Le modèle PFVD, développé par Didier Long et co-auteurs, se propose de décrire les phénomènes physiques (à une échelle mésoscopique xi = 3-5 nm) à l’origine des propriétés mécaniques des polymères amorphes apolaires proche de Tg. Ce modèle a prouvé sa pertinence puisqu'il parvient à expliquer de nombreuses propriétés des polymères vitreux : l'assymétrie entre vieillissement et rajeunissement, le décalage de Tg dans les films minces et la plasticité des polymères vitreux jusqu'au début du strain hardening notamment. Le travail de thèse présenté ici à consisté à poursuivre le développement de ce modèle de façon à décrire plus finement le mécanisme de strain hardening et de façon à valider la pertinence du modèle par sa capacité à unifier différents phénomènes physiques. L'idée fondamentale du modèle est qu'il existe une distribution de temps de relaxation au sein du matériau : à l'échelle xi, des zones très rapides et des zones très lentes coexistent et interagissent entre elles. Dans le modèle, la contrainte déviatorique abaisse les barrières d'énergie à franchir pour la relaxation alpha à l'échelle xi : le système, initialement constitué de temps de relaxation très longs par rapport au temps caractéristique d'un test mécanique, peut s'écouler plastiquement lorsqu'il est déformé. La déformation d'un polymère s'accompagne d'une orientation des liaisons monomériques. L'hypothèse de notre modèle est que cette orientation engendre une augmentation des barrières d'énergie pour la relaxation alpha à l'échelle xi, ce qui induit le strain hardening. Un paramètre d'ordre tensoriel a été introduit et quantifie l'orientation moyenne des liaisons monomériques. L'évolution dynamique de ce paramètre d'ordre a été déterminée et son influence sur la dynamique locale se fait via un invariant scalaire. Les extensions apportées au modèle PFVD permettent l'obtention de courbes contrainte-déformation conformes à celles expérimentales au cours de tests mécaniques simples. La dépendance du module de strain hardening à la température et à la vitesse de déformation, l'évolution de la distribution des temps de relaxation et l'orientation moyenne des liaisons monomériques sont comparables aux données expérimentales existantes. L'effet Bauschinger est également reproduit : le comportement mécanique lors de tests unidirectionnels successifs est conforme à celui observé expérimentalement. Lors d'une réchauffe, un matériau pré-déformé plastiquement peut libérer l'énergie qu'il a stockée sous forme de chaleur. Lorsque la pré-déformation se situe dans le domaine du strain hardening, des expériences de DSC dans la littérature montrent la présence d'un pic exothermique après Tg qui est d'autant plus marqué que la pré-déformation est grande. Le modèle permet de retrouver qualitativement ce phénomène
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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