1,720,961 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
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
Resolución de un sistema óptico a partir de la función de distribución de Wigner discreta con luz coherente
Get PDFUna característica deseable en los sistemas ópticos formadores de imágenes (SO), es que tenga
una resolución espacial suficientemente alta, para resolver en la imagen detectada detalles del
objeto. Hoy día la detección de la imagen se realiza con un CCD con lo cual un ruido aditivo se
le suma a la imagen, consecuentemente los detalles de esta imagen se pierden.
Si el objeto tiene simetría circular binario y con ruido, entonces su imagen es asimétrica. Por
consiguiente el espectro de la imagen es complejo y del modulo del espectro no se puede deducir
si este tiene ceros a lo largo de su variable frecuencial.
Cuando tenemos un objeto binario resolverlo queda limitado por el ruido y en el caso de
utilizar un microscopio es por su abertura numérica consecuentemente, el objetivo de esta
tesis, es presentar resultados experimentales cuando el objeto es binario y aproximadamente
circular de dimensiones del orden de la longitud de onda, este objeto lo iluminamos con dos
diferentes tipos iluminación altamente conocidas; luz coherente (Laser) y comparar resultados
con luz incoherente (luz blanca).
Para observar si existen ceros, en este trabajo se propone trabajar con la función de
distribución de Wigner (FDWD) en el origen domino espacial. Esto se debe a que la FDWD es
la autocorrelación del espectro de la imagen detectada y debe ser real, lo cual implica que los
ceros de ésta en principio se pueden localizar por medio de una tabla numérica o una gráfica.
En este trabajo las imágenes se detectan con un CCD cuyo pixel pitch es suficientemente
pequeño para asegurar que la frecuencia de corte de éste es mayor a la frecuencia de corte del
sistema óptico.
Al promedio de imágenes detectadas se le aplica la función de distribución de Wigner
discreta1 [DWDF ] para conocer si el objeto está resuelto por el sistema [parte óptica más
detector (CCD)]. Si la DWDF es únicamente positiva en dos veces el ancho de banda de la
función de transferencia coherente [FTC] decimos que el objeto no está resuelto; de otra forma,
el objeto se resuelve. Asumimos que la imagen detectada tiene errores sistemáticos y no
sistemáticos
Definición de objetos cuasi-puntuales para un sistema óptico en luz coherente, a partir de la función de distribución de Wigner
Get PDFEl siguiente trabajo se encuentra organizado en 8 capítulos; en el próximo capítulo se presentan brevemente los fundamentos de la teoría de imágenes a partir de la aplicación de la teoría de sistemas lineales en iluminación coherente. En el tercer capítulo se presentan la definición de imágenes de objetos circulares formadas por un microscopio y se definen las consideraciones de una fuente cuasi puntual. En el capitulo cuatro, se detalla la forma en que se obtiene la imagen estimada. En el capitulo cinco se presentan algunas propiedades de la teoría de Wigner y describimos detalladamente el trabajo experimental que se realizo con objeto de verificar la propuesta de positividad de la WDF. En el capitulo siete se presentan los resultados experimentales. Por último, las conclusiones y comentarios finales de la tesi
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