1,720,953 research outputs found
Design and Experimental Validation of a PWM-Based Digital Signal Generator Using Harmonic Synthesis
No full textDer zunehmende Einsatz digital gesteuerter leistungselektronischer Systeme hat zu einer wachsenden Nachfrage nach flexibler und präziser Signalerzeugung geführt. Im Vergleich zu herkömmlichen analogen Ansätzen bieten digitale Signalgeneratoren eine verbesserte Reproduzierbarkeit, Programmierbarkeit und Integration in moderne Steuerungsplattformen. Insbesondere die Pulsweitenmodulation (PWM) in Kombination mit der digitalen Wellenformsynthese ermöglicht die Erzeugung einer Vielzahl von Signalformen unter Verwendung von Standard-Mikrocontroller-Hardware.Diese Masterarbeit konzentriert sich auf den Entwurf und die experimentelle Validierung eines PWM-basierten digitalen Signalgenerators unter Verwendung harmonischer Synthese. Das Ziel ist es, sinusförmige und nicht-sinusförmige Referenzwellenformen digital zu erzeugen und sie am Ausgang einer leistungselektronischen Stufe unter Verwendung eines passiven Tiefpassfilters zu rekonstruieren.Die praktische Umsetzung erfolgt auf einem TMS320F28069M-Mikrocontroller in Kombination mit DRV8301-Evaluierungsboards. MATLAB/Simulink wird für den modellbasierten Entwurf und die automatische Codegenerierung verwendet, während LTspice-Simulationen die Analyse und Dimensionierung des passiven Ausgangsfilters unterstützen. Die digitalen Referenzsignale werden mit einem harmonischen Ansatz erzeugt und mit den integrierten PWM-Modulen des Mikrocontrollers in PWM-Signale umgewandelt.Die Leistung des implementierten Systems wird durch Zeitbereichsmessungen von sinusförmigen, rechteckigen und sägezahnförmigen Wellenformen sowie durch eine gemessene Amplitudenfrequenzantwort des Ausgangsfilter bewertet. Die Ergebnisse zeigen eine clÜbersetzt mit DeepL.com (kostenlose Version)The increasing use of digitally controlled power-electronic systems has led to a growing demand for flexible and precise signal generation. Compared to traditional analog approaches, digital signal generators offer improved reproducibility, programmability, and integration with modern control platforms. In particular, pulse-width modulation (PWM) combined with digital waveform synthesis enables the generation of a wide range of signal shapes using standard microcontroller hardware.This master thesis focuses on the design and experimental validation of a PWM-based digital signal generator using harmonic synthesis. The aim is to generate sinusoidal and non-sinusoidal reference waveforms digitally and reconstruct them at the output of a power-electronic stage using a passive low-pass filter.The practical implementation is carried out on a TMS320F28069M microcontroller in combination with DRV8301 evaluation boards. MATLAB/Simulink is used for model-based design and automatic code generation, while LTspice simulations support the analysis and dimensioning of the passive output filter. The digital reference signals are generated using a harmonic-based approach and converted into PWM signals using the microcontroller’s embedded PWM modules.The performance of the implemented system is evaluated through time-domain measurements of sinusoidal, square, and sawtooth waveforms, as well as through a measured magnitude frequency response of the output filter. The results demonstrate a close agreement between simulation and hardware and confirm that the proposed approach is well suited for low-voltage laboratory applications. The thesis is structured to first introduce the theoretical background, followed by simulation-based design, hardware implementation, and experimental validation.Abweichender Titel laut Übersetzung von der:dem Verfasser:inMasterarbeit FH JOANNEUM 202
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
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
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