1,720,973 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
Diagnostic des défaillances dans les systèmes industriels
No full text80 p. : ill. ; 30 cmLe présent travail a pour but de monter l'utilisation des réseaux de neurones artificiels de type PMC dans le domaine de la surveillance des systèmes industriels complexes au temps réel. cette étude est décomposée en deux parties principales : dans la première partie nous avons proposé des configurations neuronales optimales pour la détection et la localisation des défaillances FDI dans les turbine à vapeur.les entrées du réseau sont les valeurs numériques obtenues à partir des capteurs de surveillance placés dans les différents points de la turbine à vapeurs, les sorties du réseau représentent le mode de fonctionnement et les points défaillants de la turbine dans le cas d'une anomalie. dans la deuxième partie, nous avons proposé une approche simple, pour les développement d'un système de diagnostic, basée sur la combinaison entre les méthodes déterministes des arbres de défaillances et la méthode des réseau de neurones artificiels. Dans ce cas, le réseau de neurone possède deux types de données fixe obtenues à partir des arbres de défaillances et des données variables obtenues à partir des capteurs de surveillance pour sélectionner, à la sortie du réseau, la cause probable d'une défaillanc
Contribution to the dependability of hybrid solar / gas tower power plants
No full text127 p. : ill. ; 30 cmThe present work addresses two main complementary parts: the first part deals with the modeling and simulation of hybrid solar-gas tower power plant (HSTPP) performances and the second one treats the solar tower power plant (STPP) reliability analysis. An overview of HSTPP technology, current status and a presentation of the major components including the heliostat field, the solar receiver and the power conversion system are first highlighted. Then, modeling and simulation of the HSTPP performances is developed. In this study the HSTPP is divided into two main parts, the first one is the solar part or the solar tower power plant (STPP) and the second is the gas part or gas turbine power plant (GTPP). The STPP performances analysis iswell detailed in this thesis since the STPP is the most important part of HSTPP. To this end, two different methods namelythe artificial neural network (ANN) method and the analytical method using energy analysis are presented and analyzedfor the STPP performance analysis. The simulation of the performances of this STPP using these two methods has led to a very good convergence and accuracy of these results. Besides, GTPP and HSTPP performancesare evaluated and simulated in this thesis. For the STPP reliability analysis, the study focuses on specific methods such as the First Order Reliability Method (FORM). Detailed analysis concerning FORM is developed in this thesis. The same hypothetical STPP example, used for the performance analysis, is proposed also to evaluate this method. The results show that FORM is suitable to assess the reliability of STPP systems and it converges quickly. It can also adjust the first design parameters to a new safe desig
Contribution to the dependability of hybrid solar / gas tower power plants
No full text127 p. : ill. ; 30 cmThe present work addresses two main complementary parts: the first part deals with the modeling and simulation of hybrid solar-gas tower power plant (HSTPP) performances and the second one treats the solar tower power plant (STPP) reliability analysis. An overview of HSTPP technology, current status and a presentation of the major components including the heliostat field, the solar receiver and the power conversion system are first highlighted. Then, modeling and simulation of the HSTPP performances is developed. In this study the HSTPP is divided into two main parts, the first one is the solar part or the solar tower power plant (STPP) and the second is the gas part or gas turbine power plant (GTPP). The STPP performances analysis iswell detailed in this thesis since the STPP is the most important part of HSTPP. To this end, two different methods namelythe artificial neural network (ANN) method and the analytical method using energy analysis are presented and analyzedfor the STPP performance analysis. The simulation of the performances of this STPP using these two methods has led to a very good convergence and accuracy of these results. Besides, GTPP and HSTPP performancesare evaluated and simulated in this thesis. For the STPP reliability analysis, the study focuses on specific methods such as the First Order Reliability Method (FORM). Detailed analysis concerning FORM is developed in this thesis. The same hypothetical STPP example, used for the performance analysis, is proposed also to evaluate this method. The results show that FORM is suitable to assess the reliability of STPP systems and it converges quickly. It can also adjust the first design parameters to a new safe desig
Diagnostic des défaillances dans les systèmes industriels
No full text80 p. : ill. ; 30 cmLe présent travail a pour but de monter l'utilisation des réseaux de neurones artificiels de type PMC dans le domaine de la surveillance des systèmes industriels complexes au temps réel. cette étude est décomposée en deux parties principales : dans la première partie nous avons proposé des configurations neuronales optimales pour la détection et la localisation des défaillances FDI dans les turbine à vapeur.les entrées du réseau sont les valeurs numériques obtenues à partir des capteurs de surveillance placés dans les différents points de la turbine à vapeurs, les sorties du réseau représentent le mode de fonctionnement et les points défaillants de la turbine dans le cas d'une anomalie. dans la deuxième partie, nous avons proposé une approche simple, pour les développement d'un système de diagnostic, basée sur la combinaison entre les méthodes déterministes des arbres de défaillances et la méthode des réseau de neurones artificiels. Dans ce cas, le réseau de neurone possède deux types de données fixe obtenues à partir des arbres de défaillances et des données variables obtenues à partir des capteurs de surveillance pour sélectionner, à la sortie du réseau, la cause probable d'une défaillanc
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