1,721,490 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Down-sampling of large lidar dataset in the context of off-road objects extraction
Full text linkNowadays, LiDAR (Light Detection and Ranging) is used in many fields, such as transportation. Thanks to the recent technological improvements, the current generation of LiDAR mapping instruments available on the market allows to acquire up to millions of three-dimensional (3D) points per second. On the one hand, such improvements allowed the development of LiDAR-based systems with increased productivity, enabling the quick acquisition of detailed 3D descriptions of the objects of interest. However, on the other hand, the extraction of the information of interest from such huge amount of acquired data can be quite challenging and time demanding. Motivated by such observation, this paper proposes the use of the Optimum Dataset method in order to ease and speed up the information extraction phase by significantly reducing the size of the acquired dataset while preserving (retain) the information of interest. This paper focuses on the data reduction of LiDAR datasets acquired on roads, with the goal of extraction the off-road objects. Mostly motivated by the need of mapping roads and quickly determining car position along a road, the development of efficient methods for the extraction of such kind of information is becoming a hot topic in the research community
Development and application of an efficient chemical reactor network model for oxy-fuel combustion
No full textThe excessive computational cost of computational fluid dynamics (CFD) simulations of complex reactors is still a barrier to investigations using detailed chemical kinetics. Chemical rector network modeling is a promising tool for affordable numerical investigations of novel combustor technologies, such as oxy-fuel combustion, using directly coupled detailed chemical kinetics. In this work, a novel chemical reactor network solver, NetSMOKE, which is part of the OpenSMOKE++ suite, is presented and discussed. The numerical model employed, together with the relative solution method, is explained, also exploiting a combined sequential-modular and equation-oriented approach for solving the global system of equations. The novel solver was employed to build a chemical reactor network that represents the Technische Universität Darmstadt oxy-fuel burner using a reduced number of ideal reactors with directly coupled detailed kinetic models for the first time. On the basis of previously available CFD simulations and measurements, the complex flow is accurately characterized and discretized into macrozones, facilitating the development of a simplified reactor network. Carbon monoxide emissions were analyzed in detail, supported by sensitivity analysis with respect to the reactor temperatures. The sensitivity analysis revealed that the post-flame zone is crucial for the overall CO emission. Therefore, on the basis of the sensitivity analysis, an iterative approach for refining the reactor network model is developed. The increase in the number of ideal reactors in targeted areas of the system allows for significant improvements with respect to CO predictions. The chemical reactor network provides good agreement with the experimental data, requiring only a limited increase in the overall computational cost. The presented tool offers a computationally efficient strategy to investigate and predict the behavior of complex reactors, including the emission of pollutants in combustion devices, allowing for the employment of state-of-the-art, detailed chemical kinetic mechanisms available from the literature
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