1,720,998 research outputs found
Effect of multiple, intercalated sediments on seismic data
No full textSubsurface imaging using conventional seismic reflection techniques is challenging in areas where high-velocity rocks such as basalts are underlain by low-velocity rocks. The seismic image quality worsens in the presence of intercalated sediments within the basaltic rocks. This article presents an example showing possible complications expected in regions characterized by basalt flows. It further attempts to examine the applicability of using locally converted seismic waves to image the basalt layer as well as structures underneath them
Seismic imaging of glaciomarine sediments of Antarctica: optimizing the acquistion parameters
No full text412-418This paper presents some of the significant points on the designing and acquisition parameters for multi-channel seismic reflection survey in the Antarctic waters with an emphasis of imaging Glaciomarine sediments. Due to their importance in unravelling the paleoclimatic clues, we stress on the practical aspects of seismic data acquisition focussed on targeting glaciomarine sediments on the Antarctic margin. We carried out extensive forward modelling exercise assuming sub-surface model parameters from the published literature pertaining to the Eastern Antarctic Margin (EAM). The reason for choosing this area is that the Prydz Bay sector of EAM has been known to have undergone huge glacial sediment accumulation in the past due to its contiguity with the Amery Ice Shelf. In this article we suggest the best suited acquisition parameters for collecting high quality multi-channel seismic data in order to image the Glaciomarine sediments in this region
Feasibility of using magnetotelluric for sub-basalt imaging at Kachchh, India
No full textAbstract: The magnetotelluric (MT) method has been among the favorite supporting tools for seismic imaging of sub-salt and sub-basalt targets. In this paper we present an examplefrom Kachchh, India (where basaltic rocks overlie Mesozoic sedimentary rocks) and discuss the feasibility of using MT as an exploration tool in a geological setting such as this. Our results highlight the difference in magnetotelluric response caused by the thin intrabasalt layering. The key issue addressed in this paper is what MT can and cannot provide in such geological settings. First, we compute apparent resistivity and phase response curves using representative resistivity-depth models and borehole data from the study area. Later, we compare these results to assess the plausibility of using MT to image the subvolcanic sediments at Kachchh. Finally we substantiate our discussion through one-dimensional inversion of the field observed MT data from this region that exhibits poor sensitivity of MT for thin basalt layers
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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