1,720,957 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
A palynologycal study of a core in san juan de saco, Atlantic department.
No full textEl área de estudio se encuentra ubicada en la cuenca Sinú San Jacinto al Noroeste de Colombia, en las inmediaciones del corregimiento de Saco, Departamento de Atlántico. El objetivo del estudio consistió en evaluar el potencial palinológico y determinar la edad relativa para la Formación Tubará, a partir del análisis palinológico del núcleo recuperado del pozo San Juan de Saco EST-1. Asimismo, se realizó el análisis de máxima verosimilitud para comparar los resultados obtenidos en el análisis palinológico con el fin de soportar las interpretaciones realizadas. El análisis palinológico permitió identificar un total 51 morfotipos, de los cuales 28 pertenecen a polen y 23 a esporas, con los cuales se realizó una carta de distribución con los taxa identificados.En las muestras analizadas se identificaron los taxa: Cyatheacidites annnulatus, Stephanocolpites evansii a una profundidad de 247,41 m. La ocurrencia de estos taxa sugiere la Zona T-17 Cyatheacidites annulatus propuesta por Jaramillo et al., (2011), a la cual le confiere una edad relativa del Mioceno Tardío a Plioceno Temprano (7.1 - 4.8 Ma). Igualmente, se identificaron los taxa: Multimarginites vanderhamenii y Multiareolites formosus, los cuales se observaron a 58,75 m de profundidad. La ocurrencia de estos taxa sugiere la Zona T-18 Bombacacidites Baculatus que posee una edad relativa de Plioceno - Pleistoceno (4.8 0 Ma) según Jaramillo et al. (2011) complementando con datos de Muller et al (1987). Siendo así, se definió un intervalo único para la sección analizada, que abarca las zonas T-17 y T-18. Puesto que existe incertidumbre en cuanto al límite de éstas, debido al bajo recobro que exhibieron algunas muestras. Tras el análisis de máxima verosimilitud, se observó que las muestras exhiben valores de probabilidad intermedios. Sin embargo, estos resultados indican que las muestras se encuentran en intervalos de edad recientes, soportando los resultados obtenidos.PregradoGeólogoThe study area is located in the Sinú - San Jacinto basin In Northwestern Colombia, in the immediate vicinity of Saco District, Atlántico Department. The objective of this study consisted in the evalution of the palynological potential and determination of the relative age for the Tubara Formation, based on the palynological analysis of the recovered core from the San Juan de Saco EST-performed to compare the results obtained on the palynological analysis in order to support the interpretations that were made. The palynological Analysis allowed to identify 51 morphotypes, which 28 of them belong to pollen and 23 spores, which were used to develop a distribution letter with the identified taxa. In the analyzed samples the Cyatheacidites annnulatus, Stephanocolpites evansii were identified at a depth of 247,41 m. The occurrence of this taxa Suggest that the T- 17 Cyatheacidites annulatus zone proposed by Jaramillo et al (2011), which is conferred a relative age of a Late Miocene to an Early Pliocene. Likewise, the Multiareolites formosus and Multimarginites vanderhamenii were identified, which were observed at 58,75 m of depth. The occurrence these taxas suggest that the T-18 Bombacacidites baculatus zone possess a relative age of Pliocene - Pleistocene according Jaramillo et al (2011) complimenting with the Muller et al (1987) data. Thus, a unique interval was defined for the analyzed section covering the T- 17 and T-18 zones, since uncertainty exists along their limits, this is because the low recovery exhibited by some of the samples. After the maximum likelihood analysis, it was observed that the samples exhibited intermediate probability values. However, these results indicate that the samples can be found in current ages, supporting the obtained results
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
Palynology of the middle to upper Eocene Esmeraldas formation in the Nuevo Mundo Syncline area, Middle Magdalena Valley Basin, Colombia
Get PDFThe palynology of the Eocene Esmeraldas Formation in the Middle Magdalena Valley Basin, Colombia was analyzed in order to constrain the age of the unit. This formation is a very important oil reservoir in the Middle Magdalena Valley Basin, which is a product of a fragmentation of a Cenozoic foreland basin by the Northern Andes. It created structural complexities and syntectonic deposition. The lateral continuity of the formation, as well as its correlations with lithostratigraphic units is adjacent basins, are not clearly understood. The Los Corros Fossil Horizon, a mollusk horizon in the upper part of the Esmeraldas Formation, is used to differentiate the formation. This horizon is not laterally continuous all over the basin and its age is still debatable. Data from eighty-two (82) samples from an outcrop section in the Nuevo Mundo Syncline area and from seven previously studied wells have been integrated with a palynological zonation of northern South America in order to date the Esmeraldas Formation. The age ranges from the Early-Middle Eocene to Late Eocene. The Esmeraldas Formation is correlative with the upper Picacho Formation and the lower part of the Concentracion Formation in the Eastern Cordillera, and the upper Mirador Formation and the base of the Carbonera Formation in the Llanos Foothills. The Los Corros Fossil Horizon is Late Eocene and is time-correlative with a marine transgression in the central Llanos Foothills. A non-metric multidimensional scaling analysis using both the Sorensen and the Morisita-Horn Indices suggests that the floras from the Middle Magdalena Valley were different to the Llano Foothills area during the Middle to Late Eocene. This is apparently due to different environments of deposition. The results of this study will contribute to a better understanding of the overall evolution of the Middle Magdalena Valley Basin --Abstract, page iii
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
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