1,720,982 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
Interaction between the heart and a rotary blood pump : noninvasive monitoring and investigations in an isolated heart setup
No full textIn modernen implantierbaren Rotationsblutpumpen (RBP) zur Herzunterstützung sind keine Sensoren implementiert, um die kardiovaskuläre Funktion zu bestimmen. Gründe hierfür sind, dass derartige Sensoren eine erhöhte Komplexität sowie ein periodisches Kalibrieren des Systems erfordern und außerdem das Risiko eines Sensorfehlers besteht. Unsere Arbeitsgruppe hat daher Methoden entwickelt, um die Interaktion zwischen Herz und Pumpe anhand verfügbarer Pumpensignale zu überwachen. In dieser Dissertation werden drei Publikationen präsentiert, die nicht-invasive diagnostische Methoden und einen Versuchsaufbau mit einem isolierten Großtierherz und einer implantierten RBP beschreiben.
In der ersten Studie wurden die Anforderungen an ein, anhand von Pumpensignalen abgeschätztes, Pumpenflusssignal bestimmt, um diese Algorithmen in modernen RBP anwenden zu können. In Folge entwickelten wir eine Methode zur Abschätzung des Pumpenflusses basierend auf dem mathematischen Modell eines bürstenlosen Gleichstrommotors für eine RBP.
Für die statische und dynamische Identifikation der Modellparameter wurden hydraulische Kreisläufe eingesetzt. Im Vergleich zu der momentan klinisch eingesetzten Flussschätzung konnte die Frequenz-Bandbreite um das 3-fache auf bis zu 15 Hz gesteigert werden. Diese erhöhte Bandbreite ermöglicht es Informationen über den kardiovaskulären Status alleine aus dem Flusssignal abzuleiten. (Paper I) Ein weiteres Ziel dieser Dissertation war die Entwicklung einer Methode zur Detektion der möglichen Öffnung der Aortenklappe (AK) bei Patienten mit RBP anhand von Pumpensignalen. Die Methodik wurde mit Hilfe von Pumpensignalen aus numerischen Modellen und retrospektiv ausgewerteten Tierversuchen evaluiert. Um zwischen dem Status einer sich öffnenden und einer geschlossenen AK zu unterscheiden, wurde die Form des systolischen Anteils des Pumpenflusssignals analysiert und quantifiziert. Dadurch konnten korrekte Klassifizierungsraten von 99% im numerischen Modell bzw. 93% im Tiermodell erreicht werden. Die Information über den Status der AK birgt nicht nur Hinweise bezüglich des Zustandes des kardiovaskulären Systems sondern könnte in Zukunft auch eine automatische Adaption der Pumpendrehzahl für eine regelmäßige Öffnung der AK ermöglichen. (Paper II) Im dritten Teil der Arbeit wurde ein Versuchsaufbau entwickelt, um die Interaktion zwischen Herz und RBP in einem isolierten Schweineherz detailliert untersuchen zu können. Mit acht Herzen wurde die Hämodynamik unter definierten Bedingungen analysiert. In allen Versuchen konnten hämodynamische Zustände, ähnlich denen bei Patienten mit RBP, reproduziert werden. Dieser Versuchsaufbau vereint die Vorteile eines künstlichen Kreislaufes mit einem realistischen physikalischen Interface zwischen Herz und Pumpe Daher bietet diese Methode die Möglichkeit diagnostische und regelungstechnische Verfahren zu entwickeln, zu verbessern und zu validieren. (Paper III)In state-of-the-art implantable rotary blood pumps (RBPs) for circulatory support no sensors are implemented to gain information about the cardiovascular function because of risk of sensor failure, increased device complexity and the need for periodic recalibration. Therefore, our group has developed several algorithms to assess the heart-pump interaction by analyzing the available pump signals. In this thesis three publications are presented: Two papers address the noninvasive diagnostic methods and show their application to currently used RBPs.
The third paper describes an isolated porcine heart setup with an implanted RBP, which allows the investigation of the interaction between the heart and the RBP in detail. A first aim was to investigate the prerequisites for a flow estimator in order to apply the developed algorithms for assessing the heart-pump interaction to clinically used RBPs. This flow estimator was based on the mathematical model of the brushless DC motor of a centrifugal RBP.
Advanced hydraulic mock circuits were employed for experimental static and dynamic identification of the model parameters. With the developed estimator the frequency bandwidth could be increased 3-fold up to 15 Hz compared to a currently implemented pump flow estimator. Using this new estimator relevant information about the cardiovascular condition and the heart-pump interaction can be derived from pump signals only in clinically used RBPs. (Paper I) A second objective was to complement the existing algorithms with a method based on pump signals only to determine whether the aortic valve (AV) opens during RBP support. To establish and evaluate an algorithm, data from a numerical model of the assisted cardiovascular system as well as signals from retrospectively analyzed animal experiments with an implanted RBP were used. In particular, the shape of the systolic portion of the pump flow signal was quantified to discriminate between an open and closed AV. We achieved a correct classification rate of 99% and 93% of all heart beats in data derived from the numerical model and animal experiments, respectively. Using this method it becomes possible to monitor the interaction of the heart with the RBP and it even might allow automated pump speed adjustment for frequent AV opening. (Paper II) In the third paper, for a detailed experimental investigation of the heart-pump interface, an isolated porcine heart setup with an implanted RBP was introduced. In eight hearts the hemodynamics in the unassisted and assisted isolated porcine heart were analyzed under defined hemodynamic conditions. Since in this setup similar hemodynamics as observed clinically could be reproduced, the technique represents an excellent experimental tool to advance and validate both diagnostic and control methods for RBPs. It complements the experimental features offered by using mock circuits with a realistic physical interface between the heart and a RBP. (Paper III)submitted by Marcus GraneggerAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SpracheWien, Med. Univ., Diss., 2013OeBB(VLID)171449
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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