1,723,281 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
Magnetic fields or overstable convective modes in HR 7495
No full textContext. More than 200 A- and F-type stars observed with Kepler exhibit a distinctive hump and spike feature in their Fourier spectra. The hump is commonly interpreted as unresolved Rossby modes, while the spike has been linked to rotational modulation. This feature has led these stars to be referred to as ‘hump and spike’ stars. However, two competing interpretations exist for the spike.
Aims. This study aims to determine whether the observed spike in these stars is caused by magnetic phenomena, such as spots on the stellar surface, or by overstable convective (OsC) modes resonantly exciting low-frequency g modes within the star’s envelope.
Methods. We analysed photometric data from Kepler and TESS covering 4.5 years and four seasons, respectively, for HR 7495, which is the brightest hump and spike star with a visual magnitude of 5.06. Additionally, we incorporated radial velocity measurements and spectropolarimetric data from three different epochs in order to investigate magnetic fields and surface features. Furthermore, we analysed model-based artificial light and radial velocity curves to examine the influence of OsC modes on the phase-folded light curves.
Results. Our analysis of the phase-folded light curves indicates that the spike characteristics of HR 7495 align more closely with surface rotational modulation by stellar spots than with OsC modes. No significant magnetic fields were detected, which constrains the possible amplitude and geometry of the field. This is consistent with the hypothesis of a subsurface convective layer operating a dynamo, resulting in low-amplitude magnetic fields with potentially complex geometries. The variability patterns suggest multiple evolving spots. Comparing the observed light and radial velocity data with modelled OsC modes revealed a phase offset of 0.5, thus strongly disfavouring pulsations as the cause of the spike.
Conclusions. While the evolutionary stage of HR 7495 does not entirely preclude the possibility of OsC modes, the observational data overwhelmingly support the stellar spots hypothesis. Our analysis, combined with previous literature, suggests that if not all A- and F-type, at least the hump and spike stars harbour an undetected weak magnetic field that is likely driven by a dynamo mechanism
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
Optimización de planes de mantenimiento bajo metodología PMO para incrementar la disponibilidad y confiabilidad de la flota de palas 7495 de operación Toromocho
No full textEn organizaciones mineras de metales, el área de mantenimiento representa un porcentaje alto de los costos operativos (31%), en consecuencia, cualquier optimización en la gestión de mantenimiento de flota de equipos pesados es una optimización del uso de recursos para la organización.
El objetivo de esta tesis: “Optimización de planes de mantenimiento bajo metodología PMO para incrementar la disponibilidad y confiabilidad de la flota de palas 7495 de Operación Toromocho”, es elaborar planes de mantenimiento basado en la metodología Optimización de Planes de Mantenimiento (PMO) que permita incrementar la disponibilidad y confiabilidad de la flota de palas 7495.
La presente tesis aborda el contexto ocurrido en la flota de palas 7495 los cuales están operando en la operación Toromocho. Este sitio se ubica a 4,500 m s.n.m. distrito de Morococha, provincia de Yauli, Junín. El contexto operativo de la operación Toromocho es complejo para los equipos de carguío, palas 7495, por lo que se presenta problemas con la confiabilidad de las palas 7495, afectando directamente la producción de cobre.
En la presente tesis se modificaron los planes de mantenimiento y se cargó en el sistema de gestión de mantenimiento “SAP”. Se programaron y ejecutaron las actividades del nuevo plan de mantenimiento y se obtuvo como resultado el incremento de la confiabilidad. El Tiempo Medio entre Fallas del 2018 fue de 20,09 h y se incrementó el 2019 a 21,75 h con lo cual se redujo las paradas correctivas de las palas por falla, se tuvo mayor tiempo operativo en términos de utilización, mayor tonelaje movido, mayor mineral procesado y mayor producción de cobre finoIn metal mining organizations, the maintenance area represents a high percentage of operating costs (31%), consequently, any optimization in the management of heavy equipment fleet maintenance is an optimization of the use of resources for the organization.
The objective of this thesis: "Optimization of maintenance plans under the PMO methodology to increase the availability and reliability of the fleet of 7495 shovels of Operation Toromocho", is to develop maintenance plans based on the Maintenance Plan Optimization (PMO) methodology that allows to increase the availability and reliability of the 7495 shovel fleet.
This thesis addresses the context that occurred in the fleet of 7495 shovels which are operating in the Toromocho operation. This site is located at 4,500 m a.s.l. Morococha district, Yauli province, Junín. The operating context of the Toromocho operation is complex for the loading equipment, shovels 7495, for which there are problems with the reliability of the 7495 shovels, directly affecting copper production.
In this thesis, the maintenance plans were modified and loaded into the maintenance management system "SAP". The activities of the new maintenance plan were programmed and executed and the result was increased reliability. The Average Time Between Failures in 2018 was 20,09 h and increased in 2019 to 21,75 h, which reduced the corrective stops of the blades due to failure, there was a longer operating time in terms of use, greater tonnage moved, higher processed ore and higher production of fine copper.Tesi
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
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