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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
PREPARATION ET MANIPULATION DES ATOMES ET DES MOLECULES DE CESIUM
No full textAt the time of my arrival in Laboratoire Aimé Cotton (LAC) in November 2006, the activity of the experimental group of cold molecules in LAC was, on one hand on the formation and manipulation of cold molecules in a Magneto-Optical Trap (MOT), and on the other, in the realization of a dipole trap for cesium atoms. The preparation of a dipole trap of Cs atoms aimed both in the preparation of Bose-Einstein Condensation (BEC) of atomic Cs, and in the study of preparation and manipulation of Cs dimers in ultra-low temperatures. My enrollment in the activity of the experimental group of cold molecules in LAC was both in the preparation of the dipole trap, and in the study of cold molecule's creation and manipulation. In the first part of my thesis, I describe the studies conducted in the period November 2006 to October 2008. In this period, I focused my efforts on the study of different techniques for the loading of a dipole trap with Cs atoms, using a pre-existing set-up. The target was the creation of a cold and dense trapped atomic sample, in which the evaporation technique could be applied, to further cool the sample down to the critical temperature for the creation of a Cs BEC. At the beginning of the experiment, a Cs BEC had been reported only once [Web03], after years of unsuccessful efforts by many groups [Sod98, Boir98, Thom04]. Despite the difficulty of the subject, the interest in preparing samples of ultra-cold Cs atoms remained high, especially due to experiments related to ultra-cold molecules, as the creation of a molecular BEC [Herb03], or the formation of Cs trimers and the observation of Efimov states [Lee07, Knoo08]. The strategy upon which the dipole trap experiment was based, is theoretically studied in a previous publication of the group [Comp06], which considers rapid evaporation of a dense atomic sample in a crossed, deep dipole trap. This dense dipole trap, is provided by superimposing the dipole laser to a much larger trapped atomic sample, the so-called atomic reservoir. Collisions in this atomic reservoir can thermalize the sample and lead to the transfer of atoms in the dipole trap. Since this process can last for relatively large time intervals, it can result to higher loading efficiencies with comparison to alternative, instantaneous loading methods. This approach is very different to the one used in the only successful BEC experiment at that time [Web03], in which a shallow, very cold, but not so dense dipole trap, is prepared with the use of Raman Sideband Cooling. In the theoretical proposal reported in [Comp06], a magnetic trap was considered for the realization of the atomic reservoir, while the initial experimental study of this approach is the subject of a previous thesis in our group [Stern08]. However, the general ideas considered in this approach, allowed for the substitution of this magnetic reservoir, by several atomic traps. Thus, the experimental studies discussed in the first part of my thesis, are the continuation of the work made during the thesis of G. Stern [Stern08], with whom I collaborated in the beginning of my thesis. In particular, I studied the loading a dipole trap from a magnetic trap reservoir, and compared it to the loading obtained when the magnetic reservoir is replaced by a Dark-SPOT and a Compressed MOT (C-MOT). Furthermore, all these reservoir-loading methods are compared to a simpler, instantaneous-loading method which involves optical molasses. By June 2008, it was made clear that our experimental approach to the dipole trap loading, could not lead to the preparation of a sufficiently cold and dense atomic sample, in which evaporating cooling could be applied for the preparation of cesium atoms in ultra-low temperatures. In the same time, the approach considered in the first successful realization of a Cs BEC [Web03] gained ground, since the experiments reported in [Hung08] showed that it could provide with a Cs BEC with a fast and relatively simple experimental sequence. Thus, we also attempted the preparation of an ultra-cold Cs sample with the use of a shallow, not very dense, but very cold dipole trap provided by Raman Sideband Cooling. Unfortunately, a series of experimental problems related to the old vacuum system used in our experiment, prevented us from creating an ultra-cold atomic cesium sample with such an approach, despite the encouraging preliminary results. On the same period, the studies of the manipulation of cold molecules created in a MOT, conducted by members of the experimental group of cold molecules in LAC, advanced considerably, leading to the demonstration of the vibrational cooling technique reported in [Vit08]. The operating principle of the vibrational cooling technique is similar to the one of optical pumping in atoms [Kast66]. In this process, molecules that initially lie in different vibrational levels, are simultaneously excited by shaped broadband light and are accumulated to a single vibrational level via spontaneous emission. The accumulation to a single vibrational level, is accomplished by choosing to remove from the shaped pulse, all frequencies resonant to transitions from this level and thus turn it to a dark state. The technique enjoys simplicity and generality, and its demonstration opened the way for many interesting extensions, some of which are the subject of the second part of my thesis. More particularly, my activity in the cold molecule experiment which is discussed in the second part of my thesis, considered several extensions and generalizations of the vibrational cooling technique. The first extension to be considered, was the transfer of the molecular population to any pre-selected vibrational level, via optical pumping induced by more sophisticated, shaped femptosecond pulses, and is also discussed in [Sof09]. Another extension, considered the realization of vibrational cooling and molecular population transfer with the use of a broadband, non-coherent, diode light source, instead of a femptosecond laser and is reported in [Sof09b]. Another extension was considered to be the vibrational cooling of Cs molecules in their ground triplet electronic state, in addition to the ground singlet state, that was so far manipulated. Despite the optimistic initial predictions, the experimental study did not led to considerable results. However, this 'failed' experimental study, provides with an opportunity to revisit the various key elements of the vibrational cooling technique, and to consider the possible reasons that can lead to its failure. Such a discussion is particularly useful for the following study of the extension of the vibrational cooling technique to heteronuclear molecules through the example of NaCs. Finally, the generalization of the vibrational cooling technique to include rotation, which is theoretically considered in various publications of the group in which I participated [Vit09, Sof09, Sof09c], is discussed. In addition to these theoretical considerations, I discuss the preliminary experiments considered for rotational cooling, which involve the preparation of rotationally resolved depletion spectroscopy, and which are also discussed in [Fio09].Au début de mon travail de thèse dans l'équipe Atomes et Molécules Froides du Laboratoire Aimé Cotton, l'intérêt du groupe était, d'un côté, la préparation et la manipulation des molécules de Césium créées via photoassociation, et de l'autre, à la préparation d'un échantillon de Césium à basse température et de grande densité dans un piége dipolaire. Initialement, j'ai participé aux études de realization du piége dipolaire atomique, et ensuite aux études de préparation et de manipulation des molécules. Dans la période entre Novembre 2006 jusqu'a Octobre 2008 j'ai développé une série de techniques différentes pour le chargement d'un piége dipolaire à partir d'un réservoir atomique, réalisé soit par un piége magnétique, soit par un piége du type 'Dark-SPOT', soit par C-MOT (piége magnéto-optique comprimé) et un mêlasse optique. Au commencement du mon travail, un BEC de Césium a été rapporté un seule fois [Web03], après des années des efforts de plusieurs équipes [Sod98, Boir98, Thom04]. De plus, l'intérêt sur l'atome de Césium a augmenté à cause des expériences liées à la formation de trimères de Césium et des résonances du type 'Efimof' [Lee07, Knoo08]. La stratégie sur laquelle notre approche pour le chargement du piége dipolaire était basée, est discutée dans une publication rédigée avant mon intégration au sein d'équipe Atomes et Molécules Froides du Laboratoire Aimé Cotton [Comp06]. Il s'agit d'un chargement à partir d'un réservoir obtenu par un piége magnétique. L'objectif de cette proposition était la préparation d'un échantillon ultra froid avec un dispositif expérimental beaucoup plus simple que celui de la référence [Web03]. De plus, la proposition [Comp06] prédit la préparation d'un condensat de Césium en un temps beaucoup plus court que les temps de préparation rapportée dans la référence [Web03]. L'étude de la réalisation expérimentale de cette proposition théorique a déjà commencé, dans le cadre de la thèse de G.Stern [Stern08]. J'ai continué cette étude et j'ai réalisé plusieurs études avec différents types de réservoir (Dark-SPOT, C-MOT) et aussi de un type de chargement différent qui est basé sur le refroidissement par bandes latérales (Raman-Sideband Cooling). Toutes les piéges préparés par ces méthodes, avait une densité inférieure a celle nécessaire pour la réalisation d'un processus de refroidissement évaporatif, qui est nécessaire pour la réalisation d'un condensat. Les problèmes techniques que nous avons rencontrés vers Mai 2008 (destruction de vide), nous ont conduit d'arrêter les études de refroidissement des atomes, et de s'orienter vers les études de manipulation des molécules de Césium. Pendant cette période, l'équipe avait beaucoup progressé dans manipulation des molécules de Césium, et plus spécifiquement sur la réalisation du refroidissement du degré de liberté qui correspond à la vibration des molécules. La nouvelle technique que l'équipe avait introduit et qui est rapporté à la référence [Vit08], permet le refroidissement de la vibration des molécules de Césium par un laser femtoseconde faconné, avec un processus de pompage optique [Kast66]. Mon objectif dans la thématique de la manipulation des molécules froides, était d'étudier la généralisation de cette technique. Par example le transfert de la population moléculaire dans un seul état vibrationnel pré – sélectionné a été observé. Ce résultat est discuté dans la référence [Sof09]. Une autre généralisation est la réalisation du refroidissement vibrationnel et du transfert de la population moléculaire avec une source de lumière non cohérente, résultat qui est discuté dans la référence [Sof09b]. Une autre généralisation importante est le refroidissement de la rotation moléculaire. Cette étude théorique est discutée dans les articles de l'équipe auxquels j'ai participé [Vit09, Sof09, Sof09c], et les études expérimentales préliminaires dans la référence [Fio09]. Finalement, la généralisation de la technique pour le refroidissement vibrationnel des molécules heteronucleaires est discuté dans le dernière chapitre de ma thèse. Le document de ma thèse est donc divisé en deux parties, dans chacune d'elles je discute en détails ma contribution scientifique dans l'équipe Atomes et Molécules Froides du Laboratoire Aimé Cotton
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
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
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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