1,721,077 research outputs found
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
Study and optimization of femtosecond fiber laser etching technique dedicated to industrial and medical applications
No full textL’avènement des technologies lasers femtoseconde utilisant une fibre optique comme milieu amplificateur incite les industriels à se renseigner sur cette technologie. Dans ce contexte, et dans le cadre du projet Futures et Ruptures, cette thèse se propose de caractériser une nouvelle source femtoseconde, le Tangerine d’Amplitude Systèmes. Utilisant les capacités de ce laser, et avec la collaboration d’IREPA LASER, nous feront une étude comparative avec les lasers femtoseconde déjà existant en s’appuyant sur l’état de l’art, l’optique non-linéaire et quelques simulations d’ablation. L’amélioration des procédés d’usinage pour des applications industrielles nous permettra de modifier et compléter nos connaissances dans l’usinage de différents matériaux tout en montrant les qualités de cette nouvelle technologie. Enfin, une application de miniaturisation de dispositifs électronique pour le domaine du biomédical nous permettra d’utiliser toutes les connaissances acquises et de mener à bien ce projet.Surgical procedures are moving increasingly toward minimally invasive techniques because these techniques offer great comfort to the patient, a short recovery time and are reasonably-priced. As part of this thesis, it is proposed to study the integration of micrometer-sized sensors directly into needles for example. The PhD student will study the process of laser-matter interaction for new nano and femtosecond sources which should be optimized in order to develop a machining technique of surgical instruments in order to incorporate the sensors. The aim of the thesis is the demonstration of the feasibility of developing the technique of laser etching for the integration of sensors into millimeter-sized needles as well as tests in real conditions. Multiple lasers will be used; The Tangerine laser from ‘Amplitude Systèmes’ with the well know Ti:Sa laser. His work there will be to upgrade the laser up to its best capacity both in terms of fluence or accuracy and in terms of software and its ease of use. The ablation of the silicon from the rear of the electronic chip to the edge of the photodetector in order to carry the light and energy supply all 3D Hall effects micro-magnetors will be the main purpose of the PhD student. He will highlight differences between two femtosecond laser as thermally affected area or ablation rate and will choose which one is able to achieve our goal
Ultrafast laser beam tailoring for efficient surface and bulk processing
No full textInternational audienceUltrafast laser beam tailoring for efficient surface and bulk processin
Ultrafast Laser Processing using Optimized Spatial Beam Control
No full textWriting the so-called ’HDR’ manuscript (standing for the french ’Habilitation à Diriger la Recherche’) is a somewhat frightening exercise. It is naturally difficult to look back and try to summarize years of research and collaborations. More delicate is to present the advances in the frame of the most recent scientific and technological results while trying to correctly describe the state of the art. Anticipating the next developments of a fast-evolving field of research such as ultrafast laser machining is not an easier task either. However, this step appears to be indispensable in a researcher’s career when the time comes to choose the next research efforts to be conducted. I would like here to use once and only once the famous sentence that this manuscript is written "to the best of my knowledge", hoping this will excuse any short-comings and mistakes in describing the state of the art of ultrafast laser micro machining and how my work stands in this international context. Let me clarify straight away the unclear expression "my work". Behind this, one has to realize that this involve far more than what my brain alone could have ever produce, even under the most efficient drugs. Indeed, a very large group of people including patient and passionate PhD supervisors and co-supervisors, friendly and hard-working colleagues, long-suffering PhD students and postdocs altogether with an enthusiastic and caring community has to be recognized here. I also want to add on the list the many people from other scientific and research communities. It is puzzling how multi disciplinary approaches can bring together the right people at the right moment, creating the appropriate frame for breakthroughs and innovative work. I will try to give some examples of this fact that I had the chance to notice during my career. Ultrafast laser pulses have also this unique property to trigger a deep curiosity in anyone who comes to deal with them. Sometimes appearing as a magical solution’ but still being in competition with much more experienced and mastered processes, this short wavepackets of light have not ceased to surprise the world and find more and more applications, not to mention here the 2018’s Nobel Prize recognizing as a major breakthrough the possibility to amplify these pulses. I hope that this manuscript, with the efforts made to render the reading accessible and the concepts easily understandable, can trigger such interest to the largest possible audience
Ultrafast laser spatial beam shaping using an optically addressed liquid crystal optical valve
No full textInternational audienc
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
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