1,720,971 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
Suppression des courants harmoniques à base des filtres actifs triphasés à quatre fils
Get PDFLa pollution harmonique est l’un des principaux problèmes qui détériore la qualité de
l’énergie électrique dans les systèmes de distribution électrique. Les e ets nocifs les
plus évidents des harmoniques sont : Les dysfonctionnements de certains équipements électriques
dus à la présence de la pollution harmonique, l’endommagement des disjoncteurs
ou des condensateurs a ectés par un fort courant harmonique amplifié par la résonance et
l’échau ement des câbles, condensateurs et transformateurs. En comparaison avec la solution
classique contre les perturbations harmoniques, à savoir les filtres de puissance passifs,
le filtre actif de puissance parallèle (FAPP) est une solution qui présente de meilleures performances.
Ce travail de thèse porte sur l’étude et l’analyse du filtre actif parallèle triphasé a structure
de tension à quatre bras (FAP4B), qui assure la compensation de la puissance réactive,
ainsi que la suppression des harmoniques dans les systèmes électriques triphasés à quatre
fils. Afin d’e ectuer le conditionnement susmentionné, ce e thèse propose dans le cas des
tensions du réseau équilibrées et sinusoïdales, un algorithme basé sur la théorie de la puissance
réactive instantanée (PQ) avec un filtre SOGI (Second Order Generalized Integrator)
à la place du filtre passe bas classique LPF (Low pass filter) pour calculer les courants de
référence de compensation afin de contourner l’inconvénient du LPF classique relatif à l’introduction
d’un retard et l’incapacité d’extraire parfaitement les composantes fondamentales
des courants de la charge à la pulsation w = 2 f (problème de déphasage) ce qui ralentit la
réponse dynamique. Dans le cas des tensions du réseau perturbées, ce e thèse propose un
algorithme basé sur la trame de référence synchrone pour la boucle à verrouillage de phase
basée sur le mixage de l’intégrateur généralisé de deuxième et de troisième ordre (Synchronous
Reference Frame-Mixed Second and Third-Order Generalized Integrator-based Phase
Locked Loop SRF-MSTOGI-PLL) pour calculer les courants de référence de compensation et
de contourner les problème de la théorie PQ sous les conditions des tensions du réseau non
idéales. Le modèle mathématique du système de courant du FAP4B, qui se réfère aux courants de compensation, est obtenu dans la trame de référence abc puis, dans la trame de référence
stationnaire dq0, par conséquent, le contrôle du courant du FAP4B est implémenté dans les
axes dq0. Le modèle qui représente le système de la tension, qui est liée à la tension du bus
continu DC du FAP4B, est également modélisée mathématiquement, à partir de ce modèle,
il est possible de concevoir des gains du contrôleur proportionnel intégrale (PI) utilisé pour la
commande de la tension du bus continu du FAP4B, dans ce contexte, ce e thèse présente un
contrôleur robuste basé sur la fonction de Lyapunov pour la régulation de la tension continu
qui ne nécessite pas un modèle mathématique linéaire précis contrairement au contrôleur
PI et perme ant une bonne réponse dynamique avec et sans variation de la charge. Ce e
méthodologie de projet permet d’obtenir des meilleures performances du contrôle du FAP4B.
Afin de valider les analyses théoriques, ainsi que d’évaluer les performances du FAP4B, des
simulations informatiques sont réalisés avec Matlab/Simulink.La contaminación armónica es uno de los principales problemas que deterioran la calidad de la energía eléctrica en los sistemas de distribución eléctrica. Los efectos nocivos
más evidentes de los armónicos son : Mal funcionamiento de ciertos equipos eléctricos debido a la presencia de contaminación armónica, daños en los disyuntores o condensadores
afectados por una fuerte corriente armónica amplificada por resonancia y calentamiento de
cables, condensadores y transformadores. En comparación con la solución clásica contra las
perturbaciones armónicas, es decir, los filtros de potencia pasivos, el filtro de potencia activo
paralelo (FAPP) es una solución con mejores prestaciones.
Este trabajo de tesis se centra en el estudio y análisis del filtro activo paralelo trifásico con
estructura de tensión de cuatro brazos (FAP4B), que proporciona compensación de potencia
reactiva y supresión de armónicos en sistemas eléctricos trifásicos a cuatro hilos. Para llevar
a cabo el acondicionamiento mencionado, esta tesis propone en el caso de las tensiones de
la red equilibradas y sinusoidales, un algoritmo basado en la teoría PQ con un filtro SOGI (
Second Order Generalized Integrator) en lugar del filtro de paso baja clásico LPF, para calcular
las corrientes de referencia de compensación, con el fin de eludir el inconveniente del LPF
clásico relativo a la introducción de un retraso y la incapacidad de extraer perfectamente los
componentes fundamentales de las corrientes de la carga a la pulsación ω = 2πf (problema
de desplazamiento de fase), que ralentiza la respuesta dinámica. En el caso de tensiones de red
perturbadas, esta tesis propone un algoritmo SRF-MSTOGI-PLL de lazo de seguimento de fase
basado en un integrador generalizado de segundo y tercer orden para calcular las corrientes
de referencia de compensación, y evitar los problemas de la teoría PQ en condiciones de
tensiones de red no ideales. El modelo matemático del sistema de corriente FAP4B, que se
refiere a las corrientes de compensación, se obtiene en la referencia abcy luego en la referencia
estacionario αβ0, por lo tanto, el control de corriente FAP4B se implementa en los ejes αβ0.
También se modela matemáticamente el modelo que representa el sistema de tensión, que
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está relacionado con la tensión del bus continuo del FAP4B. A partir de este modelo es posible
diseñar las ganancias del controlador proporcional-integral (PI) utilizado para controlar la
tensión del bus continuo del FAP4B. En este contexto, esta tesis presenta un controlador
robusto basado en la función de Lyapunov para la regulación de la tensión continuo que
no requiere un modelo matemático lineal preciso a diferencia del controlador PI y permite
una buena respuesta dinámica con y sin variación de carga. Esta metodología de proyecto
permite obtener un mejor rendimiento de control del FAP4B. Para validar los análisis teóricos,
así como para evaluar el rendimiento del FAP4B, se realizan simulaciones por ordenador con
Matlab/SimulinkTesis Univ. Granada
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
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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