1,720,962 research outputs found
Conception et développement d'étalons de paramètres S pour la caractérisation des nanodispositifs haute fréquence
No full textThis thesis arises from work undertaking to establish reliable and traceable methods for S-parameter measurements of planar circuits. The LNE, in partnership with IEMN, is committed to continually meeting the growing needs of the RF and microwave industry, with a particular focus on the miniaturization of electronic devices.While reducing component size is essential for technological advancement, it also impacts electrical performance. These performance characteristics are assessed using measurement instruments such as vector network analyzers (VNAs), which typically operate with a nominal impedance of 50 Ω. These instruments are optimized for this impedance and are especially sensitive to variations introduced by the device under test.Miniaturization can significantly alter the impedance range, sometimes resulting in extreme values. Measuring a nanocomponent with a VNA therefore introduces challenges related to impedance matching and measurement sensitivity. For example, a high impedance nanodevice might be interpreted by the instrument as either a short or open circuit, or something close to these conditions, making accurate detection difficult and leading to highly noisy measurements.In response to these challenges, LNE is expanding its research on VNA measurement methodologies. The work aims to cover a wider frequency range, target specific impedance domains, and operate at the nanoscale. The objective is to design and develop traceable coplanar nanostructures for vector calibration, supporting an extended impedance range including extreme, low, and high values and to establish associated calibration methods that ensure the metrological verification of the measurement system.This thesis is devoted entirely to the design of new coplanar nanocomponents in a Ground–Signal–Ground (GSG) configuration for VNA calibration, specifically for on-wafer S-parameter measurements.The work addresses the key challenges and advances in RF and microwave on-wafer measurements, with special emphasis on the precise characterization of nanodevices up to 110 GHz. It covers the overall scientific context, motivations, and objectives, the state of the art in RF metrology including the fundamentals of transmission lines and S-parameters RF measurement systems, calibration and de-embedding methods, and uncertainty assessment according to the GUM. A particular focus is placed on on-wafer measurement techniques, the influence of device miniaturization, and issues related to high-impedance measurements.The thesis details the steps involved in designing and fabricating dedicated calibration kits, including the choice of technology, materials, and dimensions, electromagnetic simulations, and validation of calibration algorithms. It also presents the experimental setup for characterizing devices from DC to 110 GHz, measurement protocols, data correction procedures, reproducibility studies, and uncertainty analysis using the TRL method based on both measured and modeled standards.Furthermore, the work focuses on developing new approaches for high-impedance measurements. These approaches are experimentally validated using different calibration kits based on the multiline-TRL method. The new approaches include the well-known Short-Open-Load-Thru (SOLT) method, as well as derivative methods that integrate offsets into the standards, including Short-Short-Short-Thru (SSST), Open-Open-Open-Thru (OOOT), and Highimpedance-Highimpedance-Highimpedance-Thru (HHHT).The thesis concludes by outlining prospects for extending these methods to new applications. Overall, this research makes both theoretical and experimental contributions aimed at improving the accuracy, repeatability, and applicability of RF and microwave on-wafer measurements, particularly for increasingly miniaturized and high-impedance devices.Cette thèse s’inscrit dans le cadre de travaux visant à établir des méthodes fiables et traçables pour la mesure des paramètres S de circuits planaires. Le Laboratoire National de Métrologie et d’Essai (LNE), en partenariat avec l’Institut d’Électronique, de Microélectronique et de Nanotechnologie (IEMN), répond aux besoins croissants de l’industrie des radiofréquences (RF) et des micro-ondes, avec une attention particulière à la miniaturisation des dispositifs électroniques.La réduction de la taille des composants constitue un facteur clé du progrès technologique, mais influence aussi fortement les performances électriques. Celles-ci sont évaluées grâce à des instruments comme les analyseurs de réseaux vectoriels (VNA), optimisés pour une impédance nominale de 50 Ω, et sensibles aux variations introduites par le composant testé.La miniaturisation peut entraîner des plages d’impédance extrêmes. Mesurer un nanocomposant avec un VNA pose donc des défis majeurs d’adaptation et de sensibilité. Ainsi, un dispositif à haute impédance peut être interprété comme un court-circuit, un circuit ouvert ou une condition similaire, compliquant la détection et générant du bruit de mesure.Pour relever ces défis, le LNE développe de nouvelles méthodologies par VNA, visant à élargir la bande de fréquences, cibler des domaines d’impédance spécifiques et travailler à l’échelle nanométrique. Ce travail conçoit et développe des nanostructures coplanaires traçables pour l’étalonnage vectoriel, capables de couvrir une large gamme d’impédances, y compris extrêmes. Il s’agit aussi de mettre en place des méthodes d’étalonnage assurant la vérification métrologique du système de mesure.La thèse est consacrée à la conception de nanocomposants coplanaires en configuration Ground–Signal–Ground (GSG) pour l’étalonnage des VNAs, spécifiquement pour les mesures de paramètres S sur wafer. Elle traite des principaux défis et avancées dans la mesure RF et micro-ondes sur wafer, avec un accent sur la caractérisation précise des nanodispositifs jusqu’à 110 GHz.Le document présente le contexte scientifique, les motivations et objectifs, l’état de l’art en métrologie RF (lignes de transmission, systèmes de mesure de paramètres S), les méthodes d’étalonnage et de de-embedding, ainsi que l’évaluation des incertitudes selon le GUM. Une attention particulière est portée aux techniques sur wafer, à l’influence de la miniaturisation et aux problématiques liées aux mesures à haute impédance.La thèse détaille la conception et la fabrication de kits d’étalonnage : choix technologiques, matériaux, dimensions, simulations électromagnétiques, et validation des algorithmes. Elle présente aussi le dispositif expérimental utilisé pour caractériser les dispositifs de DC à 110 GHz, les protocoles de mesure, les corrections de données, les études de reproductibilité et l’analyse des incertitudes via la méthode TRL, sur la base de standards mesurés et modélisés.Le travail introduit également de nouvelles approches pour les mesures à haute impédance. Validées expérimentalement avec divers kits basés sur la méthode multiline-TRL, elles incluent la méthode Short-Open-Load-Thru (SOLT) et des variantes intégrant des offsets, telles que Short-Short-Short-Thru (SSST), Open-Open-Open-Thru (OOOT) et Highimpedance-Highimpedance-Highimpedance-Thru (HHHT).La thèse se conclut par des perspectives d’extension de ces méthodes à de nouvelles applications. Globalement, cette recherche apporte des contributions théoriques et expérimentales pour améliorer la précision, la répétabilité et l’applicabilité des mesures RF et micro-ondes sur wafer, notamment pour des dispositifs miniaturisés et à haute impédance
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
- …
