1,720,974 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
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
PHOTODISSOSIATION OF PARA-ARYLMETHYL BENZOPHENONE DERIVATIVES
No full textIN THE PRESENT DISSERTATION THE PHOTODISSOSIATION OF A BENZYLIC C-SI BOND OF BENZOPHENONE DERIVATIVES WAS STUDIED. THE PHOTOCHEMICAL ACTIVATION OF PARA- DIPHENYL-TRIMETHYLSILYLMETHYL BENZOPHENONE UNDERGOES TO C-SI BOND HOMOLYSIS WITH HIGH QUANTUM YIELD (Φ=0,9). USING THE PROPER MODELS-COMPOUNDS THE PARAMETRES THAT APTIMIZE THE PHOTOHOMOLYSIS OF THE BENZYLIC C-SI BOND WAS STUDIED. THE PHOTOCHEMICAL BEHAVIOUR OF THE ABOVE AND OTHER ARYLMETHYLSILYL DERIVATIVESCONFIRM MICHL'S ET AL THEORETICAL ANALYSIS REGARDING THE PHOTODISSOCIATION OF A BENZYLIC BOND. LARGE ELECTRONEGATIVITY DIFFERENCE (BETWEEN C AND SI), WEAK BOND, LARGE LOCAL EXCITATION ENERGY, EFFICIENT INTERSYSTEM CROSSING BOND PERPENDICULAR TO THE PLANE OF THE EXCITED CHROMOPHORE, HIGH ELECTRON DENSITY IN THE POSITION OF ATTACHMENT ARE CONDITIONS WHICH FACILITATE THE DISSOCIATION.ΣΤΗΝ ΠΑΡΟΥΣΑ ΔΙΑΤΡΙΒΗ ΜΕΛΕΤΑΤΑΙ Η ΦΩΤΟΔΙΑΣΠΑΣΗ ΕΝΟΣ ΒΕΝΖΥΛΙΚΟΥ C-SI ΔΕΣΜΟΥ ΠΟΥΒΡΙΣΚΕΤΑΙ ΣΕ PARA- ΘΕΣΗ ΒΕΝΖΟΦΑΙΝΟΝΗΣ. ΧΡΗΣΙΜΟΠΟΙΩΝΤΑΣ ΚΑΤΑΛΛΗΛΕΣ ΕΝΩΣΕΙΣ ΜΟΝΤΕΛΑ ΑΝΑΔΕΙΧΘΗΚΕ Ο ΡΟΛΟΣ ΤΩΝ ΠΑΡΑΜΕΤΡΩΝ ΠΟΥ ΜΕΓΙΣΤΟΠΟΙΟΥΝ ΤΗΝ ΑΠΟΔΟΣΗ ΤΗΣ ΦΩΤΟΔΙΑΣΠΑΣΗΣ ΣΤΗΝ PARA-ΤΡΙΜΕΘΥΛΟΣΙΛΥΛΟΔΙΦΑΙΝΥΛΟΜΕΘΥΛΟ-ΒΕΝΖΟΦΑΙΝΟΝΗ (ΦΟΜΟΛ=0,9): Α)Η ΙΣΧΥΣ ΤΟΥ ΔΕΣΜΟΥ Β)Η ΥΠΑΡΞΗ ΤΟΥ C=O Γ)ΗΗ ΔΙΗΓΕΡΜΕΝΗ ΚΑΤΑΣΤΑΣΗ ΠΟΥ ΜΕΣΟΛΑΒΕΙ Δ)Ο ΡΟΛΟΣ ΤΟΥ ΠΥΡΙΤΙΟΥ Ε)Η ΘΕΣΗ ΤΟΥ ΔΕΣΜΟΥ ΩΣ ΠΡΟΣ ΤΟ ΧΡΩΜΟΦΟΡΟ. ΤΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ΤΕΚΜΗΡΙΩΝΟΥΝ ΤΗ ΘΕΩΡΗΤΙΚΗ ΑΝΑΛΥΣΗ (ΑΠΟ ΤΟΝ MICHL) ΓΙΑ ΤΗ ΦΩΤΟΔΙΑΣΠΑΣΗ ΒΕΝΖΥΛΙΚΩΝ ΔΕΣΜΩΝ. ΣΥΝΟΠΤΙΚΟΣ Η ΦΩΤΟΔΙΑΣΠΑΣΗ ΕΥΝΟΕΙΤΑΙ ΛΟΓΩ: Α)ΤΗΣ ΜΙΚΡΗΣ ΙΣΧΥΟΣ ΤΟΥ C-SI ΔΕΣΜΟΥ Β)ΤΗΣ ΥΨΗΛΗΣ ΦΩΤΟΝΙΑΚΗΣ ΑΠΟΔΟΣΗΣ ΣΤΟ ISC ΤΗΣ ΒΕΝΖΟΦΑΙΝΟΝΗΣ Γ)ΣΤΗΝ ΔΙΑΦΟΡΑ ΗΛΕΚΤΡΑΡΝΗΤΙΚΟΤΗΤΑΣ ΜΕΤΑΞΥ C ΚΑΙ SI Δ)ΣΤΗΝ ΘΕΣΗ ΤΟΥ ΔΕΣΜΟΥ C-SI ΣΤΟ ΧΩΡΟ Ε)ΤΗΣ ΥΨΗΛΗΣ ΗΛΕΚΤΡΟΝΙΑΚΗΣ ΠΥΚΝΟΤΗΤΑΣ ΣΤΗΝ PARA-ΘΕΣΗ ΤΗΣ ΒΕΝΖΟΦΑΙΝΟΝΗΣ. Η ΑΝΑΛΥΣΗ ΤΩΝ ΕΝΔΙΑΜΕΣΩΝ ΚΑΙ ΤΕΛΙΚΩΝ ΠΡΟΙΟΝΤΩΝ ΣΕ ΚΑΘΕ ΦΩΤΟΧΗΜΙΚΟ ΠΕΙΡΑΜΑ ΕΓΙΝΕ ΜΕ ΦΑΣΜΑΤΟΣΚΟΠΙΑ ESR ΠΑΛΜΙΚΗ ΦΩΤΟΛΥΣΗ,, ΑΕΡΙΟ ΧΡΩΜΑΤΟΓΡΑΦΙΑ, NMR, ΦΑΣΜΑΤΟΓΡΑΦΟ ΜΑΖΑΣ
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