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La villa romana de La Olmeda 50 años después: más allá de las excavaciones arqueológicas clásicas
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ArchEyeAutomatic: UAV-gestützte Dokumentation von Denkmälern in der Archäologie
No full textField archaeology is a science in which the objects of study are often destroyed during excavation. Historical monuments are often threatened by exposure to the elements and other environmental influences. Documentation is therefore indispensable
in the former case and an essential part of the conservation process in the latter.
Documentation methods are moving more and more into the 3D space, so it makes sense to do more remote sensing in the third dimension as well. The present work is a continuation of the author’s project ArchEye, which was one of the first applications of Unmanned Aerial Vehicles (UAVs) for documentation tasks in archaeology and one of the first archaeological uses of hobbyist multi-copter technology when it started in 2009. It demonstrated the wide range of applications for small drones in archaeology. The experience of this project clearly showed that more automation could improve the efficiency of documentation. Consequently, this thesis approaches this task by leaving behind traditional 2D photo stitching and focusing on 3D recording using Structure from Motion (SfM) with the help of UAVs. The experience of the ground-based SfM approach is outlined in the author’s Master’s thesis entitled "From photos to a 3D model: open-source close range photogrammetry for use in archaeology" formed another essential basis for this work.
From the beginning, the aim of this thesis was to achieve a complete method for this approach, because on the one hand a thorough 3D documentation with UAVs and SfM requires specific strategies for the acquisition. On the other hand, the analysis of the resulting 3D data requires tools and knowledge of what can be achieved with them. The limitations of the proposed method are outlined in its specific steps.
Therefore, this thesis presents the technical parts of the data acquisition with UAVs and SfM, but also software and methods for documentation, which are elaborated on several examples. To put the results of the approach into perspective, a comparison with other 3D recording methods is shown and discussed.Die Feldarchäologie ist eine Wissenschaft, bei der die Forschungsobjekte während der Ausgrabungen oft zerstört werden. Historische Denkmäler sind häufig durch Verwitterung und andere Umwelteinflüsse gefährdet. Daher ist die Dokumentation
im ersten Fall unerlässlich und im zweiten Fall ein entscheidender Teil des Konservierungsprozesses. Aktuelle Dokumentationsmethoden nutzen zunehmend die Datenerfassung im 3D-Raum, so dass es sinnvoll ist, auch die Bauwerksdokumentation
auf die dritte Dimension auszuweiten.
Die vorliegende Dissertation setzt das Projekt ArchEye fort, das bei seinem Start im Jahr 2009 eine der ersten Anwendungen von Unmanned Aerial Vehicles (UAVs) für Dokumentationsaufgaben in der Archäologie darstellte und eine der ersten
Anwendungen der Multikoptertechnologie aus dem Hobbybereich war. Es zeigte bereits die vielfältigen Einsatzszenarien kleiner Drohnen in der Archäologie. Die Erfahrungen aus diesem Projekt machten deutlich, dass eine weitere Automatisierung
die Effizienz der Dokumentation steigern könnte. Die vorliegende Arbeit greift dieses Thema auf, indem sie über das traditionelle 2D-Photostitching hinausgeht und sich auf die 3D-Datenerfassung mit Structure from Motion (SfM) durch UAVs konzentriert. Die Erfahrungen mit dem terrestrischen Ansatz aus der Magisterarbeit des Autors mit dem Titel "Vom Foto zum 3D-Modell: Open-Source-Nahbereichsphotogrammetrie im Einsatz für die Archäologie" bilden eine weitere Grundlage dieser Arbeit.
Von Anfang an war es das geplante Ziel dieser Arbeit, eine vollständige Methode für diesen Ansatz zu realisieren, denn zum einen erfordert eine umfassende 3D-Dokumentation mit UAVs und SfM spezifische Aufnahmestrategien. Zum anderen
erfordert die Analyse der resultierenden 3D-Daten Werkzeuge und Kenntnisse darüber, was damit erreicht werden kann. Die Grenzen der vorgeschlagenen Methode werden anhand der einzelnen Schritte aufgezeigt.
In dieser Dissertation werden daher neben den technischen Bereichen der Datenerfassung auch UAVs und SfM, aber auch Software und Methoden zur Dokumentation vorgestellt und an mehreren Beispielen erläutert. Um die Qualität der Ergebnisse dieses Ansatzes zu untersuchen, wird ein Vergleich mit anderen 3D-Aufnahmeverfahren durchgeführt und verifiziert
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
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