1,720,958 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
Approche modale de la dynamique des peignes de fréquences et applications
No full textThe main focus of this manuscript is the investigation of the dynamics of optical frequency combs. Based on a spectral modal decomposition of the electric field, a full characterization of the laser dynamics is achieved by measuring the fluctuations on the four main laser parameters: the intensity, the carrier-envelope offset (CEO), the central frequency and the repetition rate. Two different experimental schemes are investigated and compared in terms of sensitivity. The intensity related dynamics is also studied. Based on a simple model, we demonstrate that the main source of noise is the pump laser via its intensity fluctuations. This noise induces phase noise, and especially CEO noise, via the fluctuations of the center of the spectrum. The coupling parameter between both quantities is the residual group velocity dispersion of the laser which has been evaluated experimentally. In a second time a machine learning protocol, called reservoir computing, is investigated. Such protocol is used as a tool for studying the laser dynamics. In addition, the optical frequency comb, studied in the first parts, is used as a hardware for the implementation of a photonic reservoir computing. The long term objective of the experiment is to go toward quantum reservoir computing. Consequently, a source of quantum states is developed. Based on a PPKTP waveguide, multimode squeezed states are produced at the scale of the laser pulses. Such states can be implemented in the reservoir computing protocol to test the capacity of such configuration compared to the classical approach.L'objectif principal de ce manuscrit est l'étude de la dynamique des peignes de fréquence optiques. Sur la base d'une décomposition modale spectrale du champ électrique, une caractérisation complète de la dynamique du laser est réalisée en mesurant les fluctuations des quatre principaux paramètres du laser : l'intensité, le décalage porteuse-enveloppe (CEO), la fréquence centrale et le taux de répétition. Deux schémas expérimentaux sont étudiés et comparés en termes de sensibilité. La dynamique liée à l'intensité est également étudiée. Sur la base d'un modèle simple, nous démontrons que la principale source de bruit est le laser de pompe via ses fluctuations d'intensité. Ce bruit induit un bruit de phase, et surtout un bruit CEO, via les fluctuations du centre du spectre. Le paramètre de couplage entre ces deux quantités est la dispersion de la vitesse de groupe résiduelle du laser qui a été évaluée expérimentalement. Dans un deuxième temps, un protocole d'apprentissage automatique, appelé "reservoir computing", est étudié. Ce protocole est utilisé comme outil pour étudier la dynamique du laser. En outre, le peigne de fréquence optique, étudié dans les premières parties, est utilisé comme support pour la mise en œuvre d'un réservoir photonique. L'objectif à long terme de l'expérience est d'aller vers un réservoir quantique. Par conséquent, une source d'états quantiques est développée. Sur la base d'un guide d'ondes PPKTP, des états comprimés multimodes sont produits à l'échelle des impulsions du laser. Ces états peuvent être utilisés dans le protocole de réservoir computing afin de tester la capacité d'une telle configuration par rapport à l'approche classique
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
Modal approach to the dynamics of optical frequency combs and applications
No full textL'objectif principal de ce manuscrit est l'étude de la dynamique des peignes de fréquence optiques. Sur la base d'une décomposition modale spectrale du champ électrique, une caractérisation complète de la dynamique du laser est réalisée en mesurant les fluctuations des quatre principaux paramètres du laser : l'intensité, le décalage porteuse-enveloppe (CEO), la fréquence centrale et le taux de répétition. Deux schémas expérimentaux sont étudiés et comparés en termes de sensibilité. La dynamique liée à l'intensité est également étudiée. Sur la base d'un modèle simple, nous démontrons que la principale source de bruit est le laser de pompe via ses fluctuations d'intensité. Ce bruit induit un bruit de phase, et surtout un bruit CEO, via les fluctuations du centre du spectre. Le paramètre de couplage entre ces deux quantités est la dispersion de la vitesse de groupe résiduelle du laser qui a été évaluée expérimentalement. Dans un deuxième temps, un protocole d'apprentissage automatique, appelé "reservoir computing", est étudié. Ce protocole est utilisé comme outil pour étudier la dynamique du laser. En outre, le peigne de fréquence optique, étudié dans les premières parties, est utilisé comme support pour la mise en œuvre d'un réservoir photonique. L'objectif à long terme de l'expérience est d'aller vers un réservoir quantique. Par conséquent, une source d'états quantiques est développée. Sur la base d'un guide d'ondes PPKTP, des états comprimés multimodes sont produits à l'échelle des impulsions du laser. Ces états peuvent être utilisés dans le protocole de réservoir computing afin de tester la capacité d'une telle configuration par rapport à l'approche classique.The main focus of this manuscript is the investigation of the dynamics of optical frequency combs. Based on a spectral modal decomposition of the electric field, a full characterization of the laser dynamics is achieved by measuring the fluctuations on the four main laser parameters: the intensity, the carrier-envelope offset (CEO), the central frequency and the repetition rate. Two different experimental schemes are investigated and compared in terms of sensitivity. The intensity related dynamics is also studied. Based on a simple model, we demonstrate that the main source of noise is the pump laser via its intensity fluctuations. This noise induces phase noise, and especially CEO noise, via the fluctuations of the center of the spectrum. The coupling parameter between both quantities is the residual group velocity dispersion of the laser which has been evaluated experimentally. In a second time a machine learning protocol, called reservoir computing, is investigated. Such protocol is used as a tool for studying the laser dynamics. In addition, the optical frequency comb, studied in the first parts, is used as a hardware for the implementation of a photonic reservoir computing. The long term objective of the experiment is to go toward quantum reservoir computing. Consequently, a source of quantum states is developed. Based on a PPKTP waveguide, multimode squeezed states are produced at the scale of the laser pulses. Such states can be implemented in the reservoir computing protocol to test the capacity of such configuration compared to the classical approach
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
- …
