1,720,992 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
An Adaptive Hybrid Maintenance Policy for a Gamma Deteriorating Unit in The Presence of Random Effect
No full textIn this paper, we propose an adaptive hybrid age/condition-based maintenance policy for units whose degradation paths can be modelled via a gamma process with random effect. The maintenance policy consists in measuring the degradation level of the unit at a first (age-based) inspection time, and in using a condition-based rule to decide whether to immediately replace the unit or to postpone its replacement to a future time that is determined, unit by unit, based on the outcome of the inspection. The optimal maintenance policy is defined by minimizing the long-run average cost rate. After each replacement the unit is considered as good as new. The lifetime of the unit is defined by using a failure threshold model. Maintenance costs are computed accounting for preventive replacement
cost, corrective replacement cost, inspection cost, logistic cost, and downtime cost (which depends on the time spent in a failed state)
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
A Prescriptive Maintenance Policy for a Gamma Deteriorating Unit
No full textMost of the recent research in the field of maintenance is focused on using more and more information about the state of the system and its environment for predicting future events and making prescriptions about maintenance and operations. Indeed, these prescriptions take the form of recommendations that do not only describe what, how, and when to conduct the maintenance but also consist in advice on how to adjust the system operating conditions for the desired outcome. By following this general idea, this paper suggests a new maintenance policy for a degrading unit that generalizes a policy recently proposed in the literature by including the possibility of influencing the remaining useful life of the unit by changing its usage rate. In fact, this policy assumes that an inspection is performed at a prefixed time and that, based on the result of the inspection, it is decided whether to immediately replace the unit or to postpone its replacement to a second predetermined time and possibly adjust its working rate, if this latter option is deemed convenient. After each replacement the unit is considered as good as new. The degradation process of the unit is described by using a gamma process based model. The unit is assumed to fail when its degradation level passes an assigned threshold. It is supposed that failures are not self-announcing and that failed units can continue to operate, though with reduced performance and/or additional costs. Maintenance costs are computed considering the cost of a preventive replacements, corrective replacements, inspections costs, logistic costs, downtime costs (which account for time spent in a failed state), and costs that account for the change of the unit working rate. This latter cost also includes the possible penalty determined by failure to comply with contract clauses. The optimal maintenance policy is defined by minimizing the long-run average reward rate
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
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