1,721,016 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
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
Δοκίμια στην οικονομετρία κατά Bayes
No full textThis thesis consists of three main essays in Bayesian Econometrics. The first essay is about Bayesian Model Averaging with non conjugate priors with an application to growth regressions. Bayesian Model Averaging is a novel technique for model selection and model averaging with a lot of virtues in terms of predictiveness. Despite the vastness of the literature, most papers deal with the natural conjugate case for the parameters of the regressors, mainly because one can get analytical expression for the posterior moments and the marginal likelihood. In this essay I extend the existing literature taking into account non conjugate priors, by considering two limiting cases of a (non conjugate) multivariate student-t distribution. For the estimation of the posterior probabilities, moments, marginal likelihood and predictive density, I proceed to Laplace Method, as it is proposed by Tierney and Kadane (1986) and Tierney, Kass and Kadane (1989) and a multivariate version of Theorem 3, of the latter paper, is derived. The approximations are nicely, incorporated to the MC(3) algorithm. An application to growth regressions shows that the departure from the natural conjugate setting results to some striking differences regarding the model selection procedure. The predictive results are strong and support the choice of the non conjugate setting. The second essay deals with the issue of objective Bayesian analysis in dynamic panel models with arbitrary cross sectional and intertemporal dependence. The objectiveness of the analysis refers to the estimation of Jeffreys prior of the model parameters. I extend the work of Phillips (1991) in a dynamic panel setting and I show, as Phillips did in a time series context, that flat priors are not suitable in dynamic models to express ignorance. The arbitrariness of the structure of stochastic term deals with the fact that no functional assumptions are made for the error process. I allow for general covariance matrices Ω and Σ, denoting the correlation among the time periods and cross sectional units respectively. I estimate the marginal posterior distribution of the autoregressive parameter for several models and I proceed to a comparison with the flat prior case. My results are similar to those of Phillips (1991). In the the third essay, I propose a Bayesian most stringent test for serial correlation. I compare a number of tests for autocorrelation that exist in the literature with the Bayesian one, in terms of power and stringency for several sample sizes and number of regressors. I show that the minimization of the Bayesian Shortcoming with respect to the prior parameter(s) is equivalent to the maximization of Power with respect to the same parameter(s) and that under particular parametric settings, the resulting test is the Most Stringent. My findings show that for certain beta priors the Bayesian test attains very good overall performance in the alternative hypothesis parameter space. I also estimate the envelope power and under these certain prior distributions the proposed test is the most stringent.Η παρούσα διδακτορική διατριβή αποτελείται από τρία κύρια δοκίμια στην Οικονομετρία κατά Bayes. Το πρώτο δοκίμιο αφορά την Μπεϋζιανή μέθοδο των κυρτών συνδυασμών υποδειγμάτων (Bayesian Model Averaging ή BMA) με μη συζυγείς εκ των προτέρων κατανομές με εφαρμογή στις παλινδρομήσεις μεγέθυνσης (growth regressions). H Μπεϋζιανή μέθοδος των κυρτών συνδυασμών υποδειγμάτων είναι μια σχετικά νέα τεχνική για την επιλογή μεταβλητών - υποδείγματος και το κυριότερο πλεονέκτημα της είναι ότι δια μέσου ενός βέλτιστου κυρτού συνδυασμού υποδειγμάτων παρέχει πολύ καλές προβλέψεις. Παρά την τεράστια σε μέγεθος βιβλιογραφία, οι περισσότερες μελέτες κάνουν χρήση της συζυγούς εκ των προτέρων κατανομής για τις παραμέτρους των ερμηνευτικών μεταβλητών, κυρίως επειδή είναι απλοί οι αλγεβρικοί χειρισμοί και προκύπτουν αναλυτικές εκφράσεις τόσο για τις εκ των υστέρων κατανομές των διαφόρων παραμέτρων του υποδείγματος όσο και για την οριακή πιθανοφάνεια των δεδομένων (marginal likelihood of the data). Σε αυτό το δοκίμιο επεκτείνω την υπάρχουσα βιβλιογραφία, λαμβάνοντας υπόψη τις μη συζυγείς εκ των προτέρων κατανομές, εξετάζοντας δύο οριακές περιπτώσεις της πολυμεταβλητής εξαρτημένης student-t κατανομής. Για τoν υπολογισμό των εκ των υστέρων πιθανοτήτων, των ροπών, της οριακή πιθανοφάνειας των δεδομένων καθώς και της προβλεπτικής πυκνότητας (predictive density), εφαρμόζω τη προσεγγιστική μέθοδο Laplace, όπως αυτή προτάθηκε από τους Tierney και Kadane (1986) και Tierney, Kass και Kadane (1989) και επιπλέον αποδεικνύω μια πολυμεταβλητή εκδοχή του θεωρήματος 3, των τελευταίων. Οι προσεγγίσεις των παραπάνω συναρτήσεων ενσωματώνονται εύκολα στον Markov Chain Monte Carlo Model Composition (MC(3)) αλγόριθμο και η εφαρμογή τους στις παλινδρομήσεις μεγέθυνσης των μη συζυγών εκ των προτέρων κατανομών δείχνει ότι η υιοθέτηση τους οδηγεί σε διαφορετικά υποδείγματα και μεταβλητές. Επίσης δείχνω ότι η προβλεπτική ικανότητα της παραπάνω μεθοδολογίας υπερτερεί της ίδιας μεθοδολογίας χρησιμοποιώντας συζυγείς εκ των προτέρων κατανομές. Η δεύτερη εργασία ασχολείται με το ζήτημα της αντικειμενικής Μπεϋζιανής ανάλυσης δυναμικών υποδειγμάτων πάνελ με αυθαίρετης μορφής συνδιακύμανση διαχρονικής και διαστρωματικής εξάρτησης. Η αντικειμενικότητα της ανάλυσης αναφέρεται στον υπολογισμό και χρήση της εκ των προτέρων κατανομής του Jeffreys για τις παραμέτρους του υποδείγματος. Στη παρούσα εργασία επεκτείνω το έργο του Phillips (1991) στα δυναμικά πάνελ και δείχνω, όπως ο Phillips στις χρονολογικές σειρές, ότι οι επίπεδες εκ των προτέρων κατανομές (flat priors) δεν είναι κατάλληλες σε δυναμικά υποδείγματα για να εκφράσουν την άγνοια. Η αυθαιρεσία της δομής του στοχαστικού όρου έγκειται στο γεγονός ότι δεν κάνω κάποια συναρτησιακή υπόθεση για τα σφάλματα, αντιθέτως υποθέτω γενικές μορφές μητρών συνδιακύμανσης Ω και Σ, που δηλώνουν τη συσχέτιση μεταξύ των χρονικών περιόδων και των διαστρωματικών μονάδων, αντίστοιχα. Υπολογίζω την οριακή εκ των υστέρων κατανομή της αυτοπαλίνδρομης παραμέτρου για διάφορα δυναμικά υποδείγματα πάνελ και προβαίνω σε σύγκριση με την περίπτωση της επίπεδης εκ των προτέρων κατανομής. Τα αποτελέσματα μου είναι παρόμοια με εκείνα του Phillips (1991). Στο τρίτο δοκίμιο, προτείνω έναν κατά Bayes πιο αυστηρό έλεγχο για αυτοσυσχέτιση. Συγκρίνω μια σειρά από στατιστικούς ελέγχους για αυτοσυσχέτιση, που υπάρχουν στη βιβλιογραφία με τον προτεινόμενο κατά Bayes έλεγχο, με βάση τη ισχύ του ελέγχου (power of the test) και της αυστηρότητας (stringency) για διάφορα μεγέθη δείγματος και αριθμού ερμηνευτικών μεταβλητών. Δείχνω ότι η ελαχιστοποίηση του ελαττώματος (shortcoming) του κατά Bayes ελέγχου σε σχέση με τις υπερπαραμέτρους είναι ισοδύναμη με την μεγιστοποίηση της ισχύoς του σε σχέση με τις ίδιες υπερπαραμέτρους και επιπλέον υπό συγκεκριμένες παραμετρικές υποθέσεις, ο έλεγχος που προκύπτει είναι ο πιο αυστηρός. Τα αποτελέσματα δείχνουν ότι για ορισμένες τιμές των υπερπαραμέτρων μιας κατανομής Βήτα, ο κατά Bayes έλεγχος επιτυγχάνει πολύ καλή συνολική απόδοση σε όρους ισχύος. Τέλος υπολογίζω τη Περιβάλλουσα Ισχύ του συγκεκριμένου προβλήματος στατιστικού ελέγχου και βρίσκω ότι υπό αυτές τις συγκεκριμένες εκ των προτέρων κατανομές ο έλεγχος κατά Bayes είναι ο πιο αυστηρός
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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