1,720,953 research outputs found
Analysis of GOCE gradiometric observations for regional gravity field improvement and geophysical applications
No full textGravity data have been used numerous times in the past in studies with geophysical purposes, taking into account the fact that they can provide considerably remarkable results with homogeneity at a global scale. The present study focuses on the evaluation of GOCE satellite data use in geophysical studies concerning the wider Hellenic and Eastern Mediterranean Sea regions. To this goal GOCE SGG data of the latest available EGG_NOM_2 and SST_PSO_2 processing lines were initially obtained. These data were processed through a series of well known methodologies, including among others filtering to retain the useful signal inside the gradiometer’s MBW, resulting to the computation of disturbing gravity gradients in the LNOF later projected to a mean orbit sphere. In order to validate the accuracy of the results, disturbing gravity gradients were computed based on the EGG_TRF_2 products as well as based on a combined global geopotential model (TIM R6 & EGM2008). The disturbing gravity gradients were then cut in a region encompassing the area of study and put on a grid of a 1 arcmin step. Specifically, for the Tzz and the (-Txx -Tyy) gradients 2D Wavelet Multi-Resolution Analysis (WL-MRA) was applied in order to remove undesired noise appearing as tracks in the final signal. Complete Bouguer anomalies were computed from them, following their downward continuation to the Earth’s surface as well as the application of the appropriate topography based corrections according to the GEBCO_2023 model. The next part of the study included the estimation of Moho depth values through two classic inverse problems: the Parker-Oldenburg one and the inverse problem of isostasy of Vening Meinesz-Moritz (VMM). A significant amount of scenarios were undertaken by making different assumptions concerning the initial Moho depth and density contrast values. The estimated Moho depth models were then compared with Moho depth models in the area of study available from the literature, as well as with seismic station values. The majority of the checks and comparisons provided satisfactory results concerning the accuracy of the estimated models, as discussed in detail in the following sections of the study.Δεδομένα βαρύτητας έχουν χρησιμοποιηθεί εκτενέστατα στο παρελθόν σε εφαρμογές γεωφυσικού ενδιαφέροντος δεδομένης της δυνατότητάς τους να προσφέρουν ιδιαίτερα χρήσιμα αποτελέσματα με ομοιογένεια σε παγκόσμια κλίμακα. Αντικείμενο της παρούσας διατριβής αποτελούσε η αξιοποίηση δεδομένων της δορυφορικής αποστολής GOCE σε γεωφυσικές εφαρμογές στον ευρύτερο Ελληνικό χώρο και την περιοχή της Ανατολικής Μεσογείου. Για τον σκοπό αυτό χρησιμοποιήθηκαν δεδομένα δορυφορικής βαθμιδομετρίας GOCE των προϊόντων EGG_NOM_2 και SST_PSO_2 της πιο πρόσφατα διαθέσιμης γραμμής επεξεργασίας της αποστολής. Τα αρχικά αυτά δεδομένα υπέστησαν επεξεργασία μέσω μιας σειράς γνωστών μεθοδολογιών, που περιελάμβαναν ανάμεσα σε άλλα και φιλτράρισμα για διατήρηση του χρήσιμου σήματος εντός του MBW του βαθμιδομέτρου, με τελικό αποτέλεσμα τον υπολογισμό διαταρακτικών βαθμίδων δυναμικού στο πλαίσιο αναφοράς LNOF και έπειτα προβεβλημένων σε μία μέση τροχιακή σφαίρα. Ο έλεγχος της εγκυρότητας των υπολογισμών έγινε μέσω της σύγκρισης τους με διαταρακτικές βαθμίδες βαρύτητας βασισμένες στο προϊόν EGG_TRF_2, αλλά και με βαθμίδες διαταρακτικού δυναμικού ενός συνδυαστικού παγκόσμιου γεωδυναμικού μοντέλου (TIM R6 & EGM2008). Στη συνέχεια τα δεδομένα απομονώθηκαν για την περιοχή μελέτης και τοποθετήθηκαν σε κάναβο με βήμα 1 arcmin. Ειδικά για τις συνιστώσες Tzz και (-Txx -Tyy) εφαρμόστηκε δισδιάστατος μετασχηματισμός με wavelet για την απομάκρυνση του ανεπιθύμητου θορύβου που εμφανιζόταν με τη μορφή τροχιών στο τελικό σήμα τους. Πλήρεις ανωμαλίες Bouguer υπολογίστηκαν από αυτές, μετά την προς τα κάτω επέκταση των βαθμίδων μέσω της μεθόδου MC SA που ακολούθησε και την εφαρμογή της κατάλληλης τοπογραφικής αναγωγής σύμφωνα με το μοντέλο GEBCO_2023. Επόμενο βήμα στην εργασία αποτέλεσε ο υπολογισμός μοντέλων βαθών Moho μέσω δύο κλασικών προβλημάτων αντιστροφής: της μεθόδου Parker-Oldenburg και του αντιστρόφου προβλήματος ισοστασίας των Vening Meinesz-Moritz (VMM). Σειρά πειραμάτων πραγματοποιήθηκαν που έκαναν χρήση διαφορετικών αρχικών μέσων τιμών βάθους και τιμών αντίθεσης πυκνότητας. Τα υπολογισθέντα μοντέλα Moho συγκρίθηκαν τόσο με διαθέσιμα μοντέλα Moho από τη βιβλιογραφία όσο και με τιμές από σεισμικούς σταθμούς στην περιοχή μελέτης. Το σύνολο των ελέγχων και συγκρίσεων έδωσε ικανοποιητικά αποτελέσματα αναφορικά με την ακρίβεια των υπολογισθέντων μοντέλων, όπως σχολιάζεται αναλυτικά στις επόμενες ενότητες της διατριβής
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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