1,720,975 research outputs found
A look at interdisciplinarity using bipartite scholar/journal networks
No full textIn this paper, we propose new means to quantify journals' interdisciplinarity by exploiting the bipartite relation between scholars and journals where such scholars do publish. Our proposed approach is entirely data-driven (i.e., unsupervised): we just rely on the spectral properties of the bipartite bibliometric network, without requiring any a-priory classification or labeling of scholars or journals. Our approach is based on two subsequent steps. First, the structure of the bipartite graph is used to co-cluster both journals and scholars in a same low-dimensional space. Then, we measure a journal's interdisciplinarity by computing various diversity metrics (Shannon entropy, Simpson diversity, Rao-Stirling index) over the journal's distance with respect to these clusters. The proposed approach is evaluated over a dataset comprising 1258 journals and 2570 scholars in the information and communication technology field
Scientific community detection via bipartite scholar/journal graph co-clustering
No full textThis paper stems from the observation that researchers in different fields tend to publish in different journals. Such a relationship between researchers and journals is quantitatively exploited to identify scientific community clusters, by casting the community detection problem into a co-clustering problem on bipartite graphs. Such an approach has the potential of leading not only to the fine- grained detection of scholar communities based on the similarity of their research activity, but also to the clustering of scientific journals based on which are the most representative of each community. The proposed methodology is purely data-driven and completely unsupervised, and does not rely on any semantics (e.g. keywords or a-priori subjective categories). Moreover, unlike "flat" data structures (e.g. collaboration graphs or citation graphs) our bipartite graph approach blends in a joint structure both the researcher's attitude and interests (i.e., freedom to select the venue where to publish) as well as the community's recognition (i.e., acceptance of the publication on a target journal); as such may perhaps inspire further scientometric evaluation strategies. Our proposed approach is applied to the Italian research system, for two broad areas (ICT and Microbiology&Genetics), and reveals some questionable aspects and community overlaps in the current Italian scientific sectors classification
Pleistocene sedimentary-tectonic history of the lacustrine deposits of the fucino basin (central apennines, Italy).
No full textAn online approach for joint task assignment and worker evaluation in crowd-sourcing
No full textThe paper tackles the problem of finding the correct solution to a set of binary choice questions or labeling tasks, by adaptively assigning them to workers in a crowdsourcing system. Such problem becomes quite challenging when we do not initially know neither workers' abilities, nor questions' difficulties (besides common a priori statistics), nor (of course) which is the correct answer. Indeed, such problem requires to jointly learn workers' abilities and questions' difficulties, while adaptively assigning questions to the most appropriate workers so as to maximize our chances to find which are the correct answers. To address such problem, we first cast it into a suitably constructed Bayesian framework which permits us to obtain an analytically tractable (closed form) single-question inference step, and then we address the more general framework via the Expectation Propagation algorithm, an approximated message-passing iterative technique. We then exploit the information gathered by the inference framework as adaptive weights for a maximum weight matching task assignment policy, proposing a computationally efficient algorithm which maximizes the entropy reduction for the questions assigned at each step
Tracing NAPL Contamination of Groundwater Using Natural Radon: A Case-Study in Roma (Central Italy)
No full textIn this research, the radioactive noble gas radon was used as a
tracer for Non-Aqueous Phase Liquids (NAPLs) contamination,
since it is much more soluble in these substances than in air or
water. Soil radon remains trapped within the NAPLs, resulting in
a local reduction in the radon concentration within close
proximity to the contaminated area. This technique was applied
to a contaminated site in Roma (Italy). The main residual NAPLs
are total hydrocarbons and methyl-tertiary-butyl ether (MTBE), a
water-soluble additive. The monitoring activities included four
sampling campaigns of groundwater from 18 wells from
February 2020 to February 2021. Concentration maps were
produced using radon data. The results show that the radon
deficit traces the location of NAPLs in the fuelling station very
well, with a residual source zone extending in NNW-SSE
direction. A good correspondence between a low amount of
radon and a higher concentration of NAPLs was found. The
peaks of Volatile Organic Compounds (VOCs) detected between
8–9 and 11–12 m depths indicate the presence of residual blobs
of NAPLs in the vadose zone of the aquifer
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
Radon as a natural tracer for monitoring napl groundwater contamination
No full textIn this research, the radioactive noble gas radon was used as a tracer for Non-Aqueous Phase Liquids (NAPLs) contamination, since it is much more soluble in these substances than in air or water. Soil radon remains trapped within the NAPLs, resulting in a local reduction in the radon concentration within close proximity to the contaminated area. This technique was applied to a contaminated site in Roma (Italy). The main residual NAPLs are total hydrocarbons and methyl-tertiary-butyl ether (MTBE), a water-soluble additive. The monitoring activities included two sampling campaigns of groundwater from 18 wells in February and May 2020. Concentration maps were produced using radon data. The results show that the radon deficit traces the location of NAPLs in the fuelling station very well, with a residual source zone extending in a NNW-SSE direction. A good correspondence between a low amount of radon and a higher concentration of NAPLs was found. A reduction in the average amount of radon in the May 2020 survey indicated a stronger remobilization of NAPLs compared to that of the February 2020 monitoring campaign. The peaks of Volatile Organic Compounds (VOCs) detected between 8–9 and 11–12 m depths indicate the presence of residual blobs of NAPLs in the vadose zone of the aquifer
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