1,720,964 research outputs found
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
Investigation of photoinduced dynamics in clusters and pulse length determination at the FEL using THz light field streaking
No full textFreie-Elektronen-Laser (FEL) stellen femtosekundenlange, hochintensive und kohärente Lichtpulse im XUV- und Röntgenbereich zur Verfügung. Sie ermöglichen dadurch einen Zugang zu einem zuvor unerschlossenen Parameterbereich innerhalb der Röntgenphysik und erlauben es, die Struktur und Dynamik von Materie auf natürlichen Zeit- und Längenskalen zu untersuchen. Nanometergroße Teilchen, wie Edelgascluster, werden während der Belichtung mit hochintensiven FEL-Pulsen in ein hochangeregtes Plasma umgewandelt. Im Folge von weiteren sekundären Prozessen kann das Nanoplasma weiter erhitzt werden. Anschließend zerfallen die Nanoteilchen in die einzelnen geladenen Fragmente.
Die Zeitskala für komplexe Elektronen- und Ionendynamik erstreckt sich von wenigen Femto- bis hin zu mehreren Hundert von Pikosekunden. Die Prozesse in Nanoteilchen, die nach der FEL-Anregung stattfinden, sind für konventionelle Pump-Probe Experimente zugänglich. Der experimentelle Zugang zu den Prozessen, die auf der Zeitskala des FEL-Pulses stattfinden, ist dagegen äußerst schwer zu realisieren. Die Technik des Lichtfeld-Streakings ist sensitiv auf den Zeitpunkt der Elektronenemission. Sie ist eine in der Attosekunden- Physik etablierte Technik und eignet sich sowohl zur Charakterisierung von ultrakurzen XUV-Pulsen als auch zur Untersuchung der komplexen Elektronendynamik in Atomen, Molekülen und Nanoteilchen.
Im Rahmen der hier vorgestellten Arbeit wird die Elektronenemission von Edelgasclustern mittels Lichtfeld-Streaking mit dem Ziel untersucht, die komplexe Elektronendynamik in Clustern direkt in der Zeitdomäne zugänglich zu machen. In einer der Untersuchungen wurde beobachtet, dass die Ionisation von Clustern erheblich schneller abläuft als von Atomen. In einer weiteren Untersuchung wurde eine neue, vorher nicht beobachtete Linie im Photoelektronenspektrum von heterogenen Xe/Ar-Mischclustern identifiziert. Die Linie wurde korrelierten Elektronenprozessen in den schon expandierten Clustern zugeordnet. Darüber hinaus wird in der vorgelegten Arbeit die Anwendbarkeit des Lichtfeld-Streakings zur Bestimmung der Längen von FEL-Pulsen mit komplexer Pulsstruktur untersucht. Hierfür wurde eine Auswahl an Methoden getroffen, die es ermöglichen, anhand von wenigen simultan gemessenen Spektren, eine zuverlässige Aussage über die Länge der FEL-Pulse zu treffen. Die Zuverlässigkeit der drei in der Arbeit vorgestellten Methoden, wurde an simulierten Streaking-Spektren und an experimentell gewonnenen Streaking-Spektren charakterisiert. Es wurde die Genauigkeit der jeweiligen Methoden zur Bestimmung der Pulslängen im Einzelschuss sowie im Mittel analysiert.
Die Ergebnisse dieser Arbeit tragen dazu bei, die Technik des Lichtfeld-Streakings zur zeitaufgelösten Untersuchung hoch angeregter Proben mit komplexer Dynamik zu etablieren und die Entwicklung effizienterer Pulsdiagnostik im XUV- und Röntgenbereich voranzutreiben.Free-electron lasers (FELs) provide femtosecond long and coherent light pulses of high intensity in the XUV and X-ray regime. They thereby provide access to a previously unexplored parameter range within X-ray physics and enable studies of the structure and dynamics of matter on natural time and length scales. Nanometer-sized particles, such as rare gas clusters, are transformed into a highly excited plasma upon exposure to high-intensity FEL pulses. As a result of secondary processes, the nanoplasma might be further heated. Subsequently, the nanoparticles decay into charged fragments. The time scale for complex electron and ion dynamics stretches from a few femtoseconds to several hundreds of picoseconds.
The processes in nanoparticles that take place after FEL excitation are accessible for conventional pump-probe experiments. Experimental access to the processes that take place on the time scale of the FEL pulse, however, is extremely difficult to realize. The technique of light- field streaking is sensitive to the instance of the electron emission. This technique is well established in attosecond physics and is suitable both for the characterization of ultrashort XUV pulses and for the investigation of the complex electron dynamics in atoms, molecules and nanoparticles. In the context of this thesis, the electron emission of rare gas clusters is investigated by means of light fi eld streaking with the aim to provide a measurement of the complex electron dynamics in clusters in the time domain. In one of the investigations it was observed that the ionization of clusters proceeds considerably faster than the ionization of atoms.
In another investigation a new, previously unobserved line in the photoelectron spectrum of heterogeneous Xe/Ar mixed clusters was identi ed. The line was assigned to correlated electronic processes in the already expanded clusters. Furthermore, the presented thesis investigates the feasibility of light field streaking to retrieve the lengths of FEL pulses with complex pulse structure. For this purpose, a selection of methods was made which allow a reliable estimation of the length of the FEL pulses to be made on the basis of a limited number of simultaneously measured spectra. The reliability of the three presented methods was characterized by simulated streaking spectra as well as by experimentally obtained streaking spectra. The accuracy of the respective methods for the estimation of the pulse lengths was analyzed in single shot mode as well as on average.
The results of this work contribute to the development of the technique of light field streaking for time-resolved investigations of highly excited samples with complex dynamics and to the development of efficient single-shot pulse diagnostics in the XUV and X-ray regime
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
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
- …
