1,720,965 research outputs found
Joint interpretation of seismic refraction tomography and electrical resistivity tomography by cluster analysis to detect buried cavities
Full text linkIn the last few years, the geophysical methods of seismic refraction tomography (SRT) and electrical resistivity tomography (ERT) are among themost used geophysical techniques for the reconstruction of subsoil geometries, for the investigation of underground cavities and also for the archaeological prospecting. However, the main disadvantage of each geophysical method is the difficulty of final interpretation of the data. In order to eliminate artifacts
and generally improve the reliability and accuracy of geophysical interpretation, it is useful to perform a joint approach of different geophysical methods, also introducing the a priori information. In this work, it is shown the integrated study of seismic refraction tomography and electrical resistivity tomography techniques, the two geophysical methods are tested on both synthetic and real data and the integration of data is useful in detecting buried cavities and also evaluate their geometric characteristics. Likelihood parameters has been defined and tested, in order to help recognizing voids from other lithological structures. Finally, a statistical approach based on cluster analysis of the P-wave velocity, the density of the seismic rays and the electrical
resistivity of the synthetic and experimental models was used. Multi-space cluster distribution maps were built, allowing to better define and interpret the anomalies of the subsoil
Individuazione di cavità attraverso tomografie elettriche e sismiche
No full textLe tecniche geofisiche sono i metodi più efficienti per ottenere informazioni sulle strutture presenti nel sottosuolo. Ad oggi,
la tomografia di resistività elettrica (ERT) è il metodo più utilizzato per il rilevamento di vuoti sotterranei, tuttavia, la combinazione
con dati derivanti da diversi metodi geofisici è l’approccio più adatto per la determinazione delle cavità. Negli ultimi
anni, la ERT è stata sempre più spesso congiunta alla tomografia sismica a rifrazione (SRT) al fine di ottenere interpretazioni
più robuste anche utilizzando un approccio di tipo statistico. La cluster analysis eseguita su unità statistiche definite
da valori di resistività elettrica, velocità delle onde P e densità sismica, ha permesso di ottenere interpretazioni ottimali
delle strutture del sottosuolo. In base al numero di cluster, le mappe di distribuzione sono state costruite in uno spazio
multiparametrico, consentendo di definire determinati limiti di variabilità per i parametri selezionati.Geophysical techniques are the most efficient methods for obtaining information on the structures present in the subsoil.
Today electrical resistivity tomography (ERT) is the most used method for the detection of underground voids, however, the
combination of experimental data from different geophysical methods is the most suitable approach for the determination of
cavities. In recent years, the ERT has been joined more and more often to the technique of seismic refraction tomography
(SRT) in order to obtain more robust interpretations also using a clustering approach. The cluster analysis performed on
static units defined by electrical resistivity values, P wave velocities, and seismic density on coincident sections, allowed
to interpret the subsoil structures. Based on the number of clusters, cluster distribution maps have been constructed in the
multi-parameter space, allowing to define certain variability limits for the selected parameters
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
Geophysical surveys to reconstruct the geological model of the urban area of Palermo, Italy.
Full text linkVariations 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
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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