1,720,956 research outputs found
Kryogene Si- und SiGeSn-Schottky-Barriere-Feldeffekttransistoren
No full textDie Kryoelektronik gewinnt zunehmend an Bedeutung für Anwendungen wie Ausleseschaltungen in der Quanteninformatik sowie für die Datenverarbeitung bei tiefen Temperaturen, bei denen konventionelle dotierte CMOS-Technologien grundlegenden Einschränkungen unterliegen. Insbesondere Dotierstoff-Freeze-out, Bandflankenverbreiterung sowie ein ungünstiges Schwellenspannungsverhalten führen bei kryogenen Temperaturen zu einer deutlichen Verschlechterung der Bauelementeigenschaften. In dieser Arbeit werden Schottky-Barrieren-Feldeffekttransistoren (SBFETs) experimentell untersucht, wobei der Schwerpunkt auf ihrem Verhalten bei kryogenen Temperaturen liegt. Der Hauptfokus liegt auf siliziumbasierten rekonfigurierbaren Feldeffekttransistoren (RFETs), die durch eine elektrostatische Kontrolle der Metall-Halbleiter-Übergänge sowohl einen n- als auch einen p-Betrieb ermöglichen. Deren elektrische Eigenschaften werden im Temperaturbereich zwischen Raumtemperatur und 4.5 K hinsichtlich des Subthreshold-Swings, der Schwellenspannung, der Transkonduktanz sowie der Ein- und Ausschaltströme analysiert. Ergänzend dazu wird ein vergleichbarer SiGeSn-basierter p-SBFET mit einer Kanalzusammensetzung von 33% Silizium, 66% Germanium und 0.5% Zinn sowie Al2O3 als Gate-Dielektrikum untersucht, um den Einfluss eines alternativen Kanalmaterials und der Gate-Stack-Struktur auf das kryogene Bauelementverhalten zu bewerten. Für die Si-RFETs wird ein stabiler Betrieb sowohl im n- als auch im p-Modus über den gesamten untersuchten Temperaturbereich nachgewiesen. Beim Abkühlen zeigt sich für beide Betriebsarten eine deutliche Verbesserung des Subthreshold-Swings, wobei bei 4.5 K Werte von 24 mV/dec für den n-Betrieb und 27 mV/dec für den p-Betrieb extrahiert wurden. Die Analyse des stromabhängigen Subthreshold-Verhaltens offenbart unterschiedliche Transportregime, bei denen die thermionische Emission den Subthreshold-Bereich dominiert, während Tunnelprozesse im Einschaltzustand bei kryogenen Temperaturen mehr an Bedeutung gewinnen. Trotz des günstigen Subthreshold-Verhaltens verschiebt sich die Schwellenspannung der Si-RFETs mit abnehmender Temperatur in eine ungünstige Richtung, wodurch sich der Einschaltpunkt vom gewünschten Arbeitspunkt entfernt. Der SiGeSn-basierte SBFET zeigt bei kryogenen Temperaturen eine vergleichbare Verbesserung der Subthreshold-Eigenschaften, einschließlich einer starken Unterdrückung des Ausschaltstroms sowie eines steilen Subthreshold-Swings von etwa 23vmV/dec bei 5 K. Im Gegensatz zu den Si-RFETs verbessert sich die Schwellenspannung des SiGeSn-Bauelements beim Abkühlen, wobei, abhängig von der angelegten Drain-Source-Spannung, Reduktionen von bis zu 25% bzw. 50% beobachtet wurden. Diese Ergebnisse verdeutlichen, dass das kryogene Schwellenspannungsverhalten maßgeblich durch das verwendete Kanalmaterial und die Gate-Stack-Struktur beeinflusst wird und keine Eigenschaft von Schottky-Barrieren-Bauelementen darstellt. Zusammenfassend zeigt diese Arbeit, dass Schottky-Barrieren-basierte Transistoren ein robustes Betriebsverhalten bei kryogenen Temperaturen mit deutlich verbesserten Subthreshold-Eigenschaften aufweisen. Gleichzeitig wird deutlich, dass ein günstiges Schwellenspannungsverhalten weiterhin eine zentrale Herausforderung für Sibasierte RFETs darstellt, was zukünftige Arbeiten zur gezielten elektrostatischen Optimierung sowie zur Untersuchung alternativer Kanalmaterialien für energieeffiziente kryogene Elektronik motiviert.Cryogenic electronics is gaining increasing relevance for applications such as readout and control circuits for quantum qubits and low-temperature data processing, where conventional doped CMOS technologies suffer from fundamental limitations. In particular, dopant freeze-out, band-tail effects and an unfavourable threshold-voltage increase significantly degrade the device performance at cryogenic temperatures. In this thesis, Schottky-barrier field-effect transistors (SBFET) are experimentally investigated with a particular focus on their behaviour at cryogenic temperatures. The primary focus lies on Si-based reconfigurable field-effect transistors (RFETs), which enable both n-type and p-type operation by an electrostatic control of metal-semiconductor junctions. Their electrical characteristics are analyzed between the room temperature and 4.5 K with respect to subthreshold swing, threshold voltage, transconductance and on- and off-state currents. In addition, a similar SiGeSn-based p-SBFET with a channel composition of 33% silicon, 66% germanium, and 0.5% tin and Al2O3 as the gate dielectric is being investigated to evaluate the influence of an advanced channel material and gate stack structure on the behavior of cryogenic devices. For the Si RFETs, stable operation is demonstrated for both n-mode and p-mode over the entire investigated temperature range. Upon cooling, a pronounced improvement of the subthreshold swing is observed for both operation modes, reaching values of 24 mV/dec for n-type and 27 mV/dec for p-type operation at 4.5 K. An analysis of the current-dependent subthreshold behaviour reveals distinct transport regimes, with thermionic emission dominating the subthreshold region and tunneling processes becoming increasingly relevant in the on-state at cryogenic temperatures. Despite the favourable subthreshold swing, the threshold voltage of the Si RFETs shifts undesirable with decreasing temperature, moving the on-state away from the desired operating point. The SiGeSn SBFET exhibits a similar improvement of the subthreshold characteristics at cryogenic temperatures, including a strong suppression of the off-state current and steep subthreshold swings of approximately 23 mV/dec at 5 K. In contrast to the Si RFETs, the threshold voltage of the SiGeSn device improves upon cooling, with reductions of up to 25% and 50% depending on the applied drain bias. These results indicate that the cryogenic threshold-voltage is strongly influenced by the channel material system and the gate-stack structure rather than being a property of Schottky-barrier devices. Overall, this thesis demonstrates that Schottky-barrier based transistors provide robust cryogenic operation with strongly improved subthreshold behaviour. At the same time, the results highlight that achieving favourable subthreshold behaviour remains a key challenge for Si-based RFETs, motivating the future work on electrostatic optimization and alternative channel materials for low-power cryogenic electronic systems
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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