1,721,027 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
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
Thermal characterization of matter using the 3w method
No full textCette thèse de doctorat porte sur le développement d'un banc de mesure pour la caractérisation thermique de la matière. Les techniques et instruments employés pour la mesure des propriétés thermo-physiques sont nombreux, évoluent constamment et font toujours l'objet de nombreuses recherches. Ils sont néanmoins bien souvent adaptés préférentiellement à un état de la matière et à la mesure spécifique d'un paramètre thermique.Le banc développé repose sur la méthode dite 3-omega, qui consiste à observer la réponse thermique fréquentielle d'un matériau soumis à un flux de chaleur harmonique. Cette technique met à profit l'effet thermo-résistif qui accomplit la transduction du domaine thermique vers le domaine électrique. Elle permet alors de mesurer simplement les variations de température en fonction de la fréquence d'excitation donnant ainsi accès aux propriétés thermo-physiques du milieu étudié.Nous montrons que la méthode 3-omega permet effectivement d'une part de mesurer efficacement la conductivité thermique, mais également d'estimer la capacité thermique isobare. De plus, alors qu'elle a été initialement introduite pour la caractérisation des solides, nous élargissons son champ d'application via un dispositif expérimental adapté et un nouveau type de capteur, pour l'étendre aux autres états de la matière, à savoir les liquides et aux gaz. Le capteur proposé est fabriqué à l'aide des techniques de la micro-électronique et basé sur la technologie du silicium, ce qui permet de réduire ses dimensions et offre des perspectives intéressantes en termes de miniaturisation et d'intégration.This PhD thesis is devoted to the development of a measurement bench for thermal characterization.Nowadays, sensing techniques and instruments dedicated to this propose are numerous and evolve constantly : they still are an important research area. However, each instrument deals preferentially with one state of matter and measure mostly a unique thermal parameter. This measurement bench uses the so-called 3-omega technique, which consists in the measurement the thermal frequency response of a medium subject to an harmonic thermal heat flux. It is based on the thermo-resistive effect that links the thermal domain to the electrical domain. It therefore gives an easy way to measure the thermal variations in function of the frequency and allows the determination of the thermal properties.Initially introduced for solids, we show that this tool can indeed measure the thermal conductivity but also gives access to thermal capacity. Moreover, we expand its field of applications to other states of matter : liquids and gases.The sensor is fabricated using the microelectronics techniques and uses the silicon technology. That allows to reduce its dimensions and offers interesting prospects in terms of miniaturization and integration
Study and development of microtechnologies on paper based substrat applied to the structuration of porous AL2O3 for humidity sensor +
No full textL'objectif premier de ce projet est la mise au point de procédés de fabrication microélectroniques/microtechnologiques compatibles avec l'utilisation d'un support papier. Pour cela, des techniques comme l'évaporation thermique sous vide, la photolithographie, l'électrodéposition et l'anodisation d'aluminium ont été développées et adaptées à ce support. Des bancs de caractérisations structurels, électriques et flexibles ont été aussi mis en œuvre pour étudier la fiabilité des couches déposées sur un tel substrat. En application, un capteur d'humidité à base d'oxyde d'aluminium flexible a été fabriqué et les tests en humidité ont montré d'excellents résultats permettant de valider le travail effectué.The primary objective of this project is the implementation of microelectronics/microtechnology processes compatible with the use of paper-based substrate. For this purpose, techniques such as thermal vacuum evaporation, photolithography, electroplating and anodizing aluminum have been developed and adapted to this substrate. Structural, electrical and flexible characterizations benches have also been implemented to study the reliability of the layers deposited on such substrate. A moisture sensor based on flexible aluminum oxide was made and humidity tests have shown excellent results which validate the work
Study and realization of thermal sensing gyroscopes
No full textCe travail de thèse porte sur l’étude et la réalisation de micro-capteurs dédiés à la mesure de vitesse angulaire par des principes basés sur des échanges thermiques. Deux types de gyromètres ont été développés dont la principale différence est liée au principe qui permet la mise en mouvement du gaz : convection forcée pour l’un et expansion thermique pour l’autre. Le principe est basé sur la modification par la force de Coriolis des échanges thermiques dans un fluide chauffé localement lorsque le dispositif est soumis à une vitesse de rotation. L’utilisation d’un fluide comme masse sismique est en rupture avec les concepts de gyromètres dits traditionnels. Cet avantage a pour conséquence la possibilité d’une utilisation dans des conditions environnementales sévères telles que de fortes accélérations (> 10 000 g) et de fortes vibrations. Les objectifs de ce travail consistent à étudier, à développer et à caractériser ces deux types de gyromètres. Pour cela, des études numériques ont été menées afin de mieux appréhender les phénomènes physiques et thermiques mis en jeu dans la cavité. On a pu aussi étudier l’effet des paramètres thermo-physiques du fluide, des différentes dimensions géométriques et de la vitesse d’écoulement du gaz sur la sensibilité et l’étendue de mesure. Par ailleurs, des prototypes des deux types de gyromètres ont été réalisés puis caractérisés. Les résultats sont très encourageants et les principes validés, mais leur confrontation avec ceux de la simulation montre que des améliorations sont à apporter sur le modèle numérique.This PhD thesis deals with both study and fabrication of micro-sensors dedicated to the measurement of angular velocity, these devices are based on heat exchanges. Two types of gyroscopes have been developed, one using a jet of gas being deflected by the rotation, the other one using thermal expansion of a gas. Under rotation, heat transfers in a locally heated fluid is modified by the Coriolis force and induces a change in temperature distribution. Using a fluid as seismic mass enhances performances in terms shock (> 10 000g) and vibration resistances compared with standard mechanical gyroscopes.The aim of this work has been to study, develop and characterize these two gyroscopes. For this purpose, numerical studies have been carried out in order to improve our understanding of physical and thermal phenomena involved in the device. Effects of thermo-physical parameters, sensor size and gas flow velocity on both sensitivity and measuring range were analyzed.On the other hand, prototypes of both gyroscopes were manufactured and characterized. The proof of concept has been validated and encouraging results have been found. Comparison of measure and simulation have shown that improvements have to be made on the numerical model
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
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