1,720,982 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
An hybrid command governor supervisory scheme for flight control systems subject to unpredictable anomalies -Fault Detection, Supervision and Safety for Aircraft and Spacecraft Systems
No full textAn hybrid command governor supervisory scheme for flight control systems subject to unpredictable anomalies
No full textIn this paper, we develop a hybrid supervisory control architecture in a real-time environment for constrained control systems. The strategy is based on Command Governor (CG) ideas and is tailored to jointly take into account time-varying set-points/constraints and unpredictable anomalies in the nominal dynamical plant behaviour. The significance of the method mainly lies in its capability to avoid constraint violation and loss of stability regardless of any configuration change occurrence in the plant/constraint structure by commuting the current CG with a new on-line computed unit. Simulations on an High Altitude Performance Demonstrator (HAPD) unmanned aircraft with redundancy control surfaces show the effectiveness of the proposed strategy. © 2013 IEEE
Mining sponge phenomena in RNA expression data
No full textIn the last few years, the interactions among competing endogenous RNAs (ceRNAs) have been recognized as a key post-transcriptional regulatory mechanism in cell differentiation, tissue development, and disease. Notably, such sponge phenomena substracting active microRNAs from their silencing targets have been recognized as having a potential oncosuppressive, or oncogenic, role in several cancer types. Hence, the ability to predict sponges from the analysis of large expression data sets (e.g. from international cancer projects) has become an important data mining task in bioinformatics. We present a technique designed to mine sponge phenomena whose presence or absence may discriminate between healthy and unhealthy populations of samples in tumoral or normal expression data sets, thus providing lists of candidates potentially relevant in the pathology. With this aim, we search for pairs of elements acting as ceRNA for a given miRNA, namely, we aim at discovering miRNA-RNA pairs involved in phenomena which are clearly present in one population and almost absent in the other one. The results on tumoral expression data, concerning five different cancer types, confirmed the effectiveness of the approach in mining interesting knowledge. Indeed, 32 out of 33 miRNAs and 22 out of 25 protein-coding genes identified as top scoring in our analysis are corroborated by having been similarly associated with cancer processes in independent studies. In fact, the subset of miRNAs selected by the sponge analysis results in a significant enrichment of annotation for the KEGG32 pathway "microRNAs in cancer"when tested with the commonly used bioinformatic resource DAVID. Moreover, often the cancer datasets where our sponge analysis identified a miRNA as top scoring match the one reported already in the pertaining literature
A hybrid real-time supervisory scheme for nonlinear systems
No full textIn this paper we develop a hybrid supervisory control architecture in a real-time environment for constrained nonlinear systems. The strategy is based on Command Governor (CG) ideas that are here specialized in order to take into account both time-varying set-points and constraints. Experimental results on a laboratory four-tank test-bed are presented. © 2011 AACC American Automatic Control Council
A Hybrid Real-Time Command Governor Supervisory Scheme for Constrained Control Systems
No full textIn this paper, we develop a hybrid supervisory control architecture in a real-time environment for constrained control systems. The strategy is based on Command Governor (CG) ideas that are here specialized to consider both time-varying set-points and constraints. The significance of the method mainly lies on its capability to avoid constraints violation and loss of stability regardless of any configuration change occurrence in the plant/constraint structure by replacing the current CG with a new on-line computed unit. A real-time scheme is an extremely appealing choice because of its numerous engineering applications: automobile industry, defense and aerospace, chemical and nuclear plant applications, multimedia/telecommunications, and so on. Experimental results on a laboratory four-tank test-bed and simulations on a Cessna 182 aircraft model show the effectiveness of the proposed strategy
Embedding Norm-Bounded Model Predictive Control, Allocation strategy for the High Altitude Performance, Demonstrator (HAPD) Aircraft
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