1,721,000 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
Iterative selection of countermeasures for intelligent threat agents
No full textWe describe a model-based approach to select cost-effective countermeasures for an information and communication technology infrastructure under attack by intelligent agents. Each agent tries to reach some predefined goals through a sequence of attacks. The proposed approach builds the models of the infrastructure and of the agents, and then it applies a Monte Carlo method that runs multiple, independent simulations of the agent attacks. These simulations produce a statistical sample that is used to assess the risk. The selection of countermeasures works in an iterative way where each iteration selects some countermeasures and applies the Monte Carlo method to evaluate any residual risk. In this way, it takes into account that an intelligent agent may select distinct attacks to replace those affected by the countermeasures. To improve cost effectiveness, the selection focuses on useful attacks to reach a goal. The Haruspex suite is an integrated set of tool to support this approach. Some of its tools build the models of the agents and the one of the system. Another tool uses these models to apply the Monte Carlo method and simulate the agent attacks. This tool is iteratively invoked by the one that select countermeasures. We describe the adoption of the suite to assess and manage the risk of three industrial control system
Potential for dietary uptake of estrogens via macroinvertebrates in River Po fish
No full textSeveral substances, both man-made and of natural origin, are known to potentially affect the endocrine system of fish. They generally enter the aquatic environment through the discharges of domestic and industrial origin, and particularly estrogens, perhaps the most investigated of the endocrine disrupters, are suspected to cause altered gonadal development in wild fish populations. After the observation of intersexual cyprinids in the River Po, many studies have been undertaken, particularly along its middle section where a polluted tributary, the River Lambro, is suspected to be an effective source of EDs to the major Italian watercourse. An objective of these studies was to investigate whether fish diet may be a significant route of uptake of estrogens. To this aim, several multiplate samplers were placed upstream and downstream from the confluence of the River Lambro, and after one month of exposure, macroinvertebrates were collected and identified to order or family. Gammaridae, Ephemeroptera and Trichoptera were analysed for target estrogenic compounds (E1, E2, E3, EE2, OP, NP, BPA) in High Performance Liquid Chromatography/Multiple Reaction Monitor (HPLC/MRM). The concentrations of EDs determined in the three groups of macroinvertebrates were consistently higher downstream from the confluence of the River Lambro. In the most polluted downstream stretch, t-OP was found at 100 ng/g, whereas both NP and BPA reached levels of 600 ng/g. Surprisingly, also estriol was bioaccumulated up to 800 ng/g. Marked differences in the levels of contaminations were evident among the three groups of invertebrates also suggesting that diet may differently contribute to estrogens uptake
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
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