1,720,957 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
FDTD simulation of the propagation of electromagnetic waves in an inhomogeneous magnetized cold plasma
No full textLAUREA MAGISTRALEL'obiettivo di questo lavoro è la descrizione del comportamento di un plasma non omogeneo magnetizzato in seguito all'interazione con un'onda elettromagnetica. A questo scopo si è utilizzato un codice Full-wave, il metodo FDTD. Anche chiamato metodo di Yee, è un metodo di modellizzazione numerica basato sulle equazioni differenziali; è stato utilizzato in un'ampia gamma di problemi di elettromagnetismo, dall'analisi al design di problemi di propagazione elettromagnetica e altre applicazioni ingegneristiche. Solo più recentemente questo metodo è stato applicato per descrivere la propagazione di onde in mezzi dispersivi e anisotropi, inclusi i materiali magneto attivi.
L'interesse in questo ambito è dovuto alla varietà di materiali anisotropi, utilizzati soprattutto nell'ottica dei segnali.
Anche il mezzo protagonista di questa tesi, il plasma, mostra il suo comportamento anisotropo quando si trova in presenza di un campo magnetico esterno.
Nella prima parte di questa tesi è stato sviluppato il caso più semplice, sia per la configurazione 1D che per quella 2D. Inizialmente è stato modellizzato un mezzo meno complesso di un plasma, ovvero un dielettrico arbitrario, ed è stata descritta la propagazione di un'onda elettromagnetica attraverso di esso. In seguito alla valutazione della potenza trasmessa e riflessa per alcuni casi test, e il calcolo dei coefficienti di riflessione e trasmissione, il problema investigato è stato generalizzato al caso di una configurazione contenente un plasma freddo.
Il codice full-wave è stato inizialmente applicato ad una situazione specifica, in cui vi fosse un plasma freddo non collisionale e non magnetizzato e una sorgente che avesse un'incidenza ortogonale rispetto alla superficie. Progressivamente le varie ipotesi semplificative sono state rimosse per arrivare alla situazione generale di plasma freddo collisionale e magnetizzato, e onda con incidenza non normale.The main purpose of this work is the description of inhomogeneous magnetized cold plasma's behaviour during the interaction with an electromagnetic wave and through a Full-wave code based on the FDTD approach. Also called Yee's method, it belongs to the class of grid-based differential numerical modeling methods and it gives direct solutions of Maxwell's equations. It has been used in a great variety of electromagnetic problems involving the analysis and design of electromagnetic propagation and other engineering applications. Only more recently it has been used to model wave propagation in dispersive and anisotropic media including magnetoactive plasmas.
This interest is due to the great number of anisotropic material, mainly used in optical signal processing.
Also the medium used in this work, the plasma, exhibits an anisotropic behavior when an external magnetic field is applied.
In the first part of the thesis a simpler situation has been developed, either for 1D or 2D cases; rather than starting directly from a plasma medium, an arbitrary dielectric has been modeled and the wave propagation through it has been studied. After the computation of reflection and transmission coefficients, and the evaluation of transmitted and reflected power for some test cases, the same simulations have been generalized to a configuration where the dielectric has been substituted by a cold plasma.
The full-wave code has been applied first to the case of a collisionless unmagnetized cold plasma and a normally incident wave, then removing the simplifying hypotheses one at a time, the most general case has been simulated: collisional magnetoactive plasma and oblique incidence of the source wave
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
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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