1,720,965 research outputs found
Deep sea archaeological survey in the Black Sea – robotic documentation of 2,500 years of human seafaring
No full textBetween 2015 and 2017 the Black Sea Maritime Archaeology Project (Black Sea MAP) discovered and recorded 65 shipwreck sites dating from the 4th Century BC to the 19th Century AD in the Bulgarian Exclusive Economical Zone (EEZ). Using state-of-the-art remotely operated vehicles to survey the seabed, the team captured more than 250,000 high-definition (HD) photographs; hundreds of hours of ultra high-definition (UHD) video together with acoustic bathymetric, laser, side-scan sonar and seismic data. The wrecks were located in depths from 40 to 2,200 metres – those shipwrecks in the deeper range presented extraordinary archaeological preservation due to the Black Sea’s anoxic conditions. This paper will introduce the range of deep-sea optic and acoustic survey techniques to accurately record and create 3D and pseudo 4D models of the shipwrecks. It will focus on a Early 4th Century BC shipwreck demonstrating the project’s survey strategy as well as adaptations developed in response to operational conditions; the implementation of deep sea robotics to generate georeferenced high-resolution photogrammetric models and the benefits this has as an on-site, as well as a post-cruise, interpretative tool. It demonstrates that in-theatre acquisition and processing of high-quality datasets is a working reality and has fundamental implications for management as well as the advantages that this brings to the archaeological research process: Firstly, in the creation of spatio-temporal models, i.e., 4D representations of a site pre and post archaeological excavation and secondly, in monitoring such wreck sites, and provides a viable non-intervention tool for the assessment of sites as part of a long-term management strategy. It also shows the value of well-funded collaboration between academia and industry and that deep water archaeology can and must be totally in accordance to the 2011 United Nations Educational, Scientific and Cultural Organization (UNESCO) convention
Maritime lives in Iron Age Britain
No full textIron Age coastal communities in England have been poorly understood since the beginning of our discipline. This is mainly as result of the lack of evidence for everyday maritime activities and also the focus of research on explaining an agro-pastoral way of living. Evidence of fishing, boats, harbour structures and ports are very rare archaeologically, and thinking about people living by the sea in this period has been widely overlooked as most of the interest has been the nature of the connections and trade-networks (mainly by Cunliffe 2008). In contrast, evidence for non maritime activities, such as farming and cattle rearing is so rich that looking to the coast only happens in special situations.Using the Isles of Scilly as a case study, this research challenges the established views that societies on the coasts of south-west of England were mainly cattle herders and farmers. Through palaeolandscape reconstruction, site analysis and material culture study, this research argues that settlement on the coastline is as important as that found inland. It shows that Iron Age maritime aspects of culture were deeply embedded within cultural traditions and that the maritime way of living had little to do with extraordinary or unusual situations.This research shows that preconceived ideas of what a maritime site should look like, as is the case of harbour structures and important ports, divert the attention from the subtleties of recognising maritime culture’s signature. It is through the study of archaeological context and environmental evidence that these are likely to become more obvious. Therefore, throughout this document the analysis of maritime landscape, settlement pattern and material culture generates new perspectives on how to approach the study of maritime societies in archaeology.<br/
4D Modelling of Low Visibility Underwater Archaeological Excavations Using Multi-Source Photogrammetry in the Bulgarian Black Sea
No full textThis paper introduces the applicability of underwater
photogrammetric survey within challenging conditions as the main
tool to enhance and enrich the process of documenting archaeological
excavation through the creation of 4D models. Photogrammetry was
being attempted on underwater archaeological sites at least as early
as the 1970s’ and today the production of traditional 3D models is
becoming a common practice within the discipline. Photogrammetry
underwater is more often implemented to record exposed underwater
archaeological remains and less so as a dynamic interpretative tool. Therefore, it tends to be applied in bright environments and
when underwater visibility is > 1m, reducing its implementation
on most submerged archaeological sites in more turbid conditions.
Recent years have seen significant development of better digital
photographic sensors and the improvement of optical technology,
ideal for darker environments. Such developments, in tandem with
powerful processing computing systems, have allowed underwater
photogrammetry to be used by this research as a standard recording
and interpretative tool. Using multi-source photogrammetry (5,
GoPro5 Hero Black cameras) this paper presents the accumulation of
daily (4D) underwater surveys carried out in the Early Bronze Age
(3,300 BC) to Late Ottoman (17th Century AD) archaeological site of
Ropotamo in the Bulgarian Black Sea under challenging conditions
(< 0.5m visibility). It proves that underwater photogrammetry can
and should be used as one of the main recording methods even in low
light and poor underwater conditions as a way to better understand
the complexity of the underwater archaeological record
Морски археологически проект Черно море
No full textIn 2017 the deep water research was carried out with the state of the art vessel “Havila Subsea”. By 6 m vibrocorer were taken 16 cores and by 18 m piston corer were taken another four. In total in 2016 and 2017 a coring program at 92 locations was accomplished resulting in 394 m of core samples (fig. 1). In 2017 23 shipwrecks were studied by ROVs to a maximal depth of 2111 m (fig. 2). Among the most important discoveries is the Ancient Greek shipwreck dated to the late 5th c. BC (fig. 3), the three Roman wrecks dated to 1st–4th c. and the Early Byzantine one dated to the 5th–6th c. During 2015–2017 MAP Black Sea project discovered and studied 61 shipwrecks presenting examples of vessels from all historical ages: form the time of the Early Classical Greek period up to the 19th c. Most of them have a very high degree of conservation of wooden hulls, making the Black Sea one of the most promising areas for researches on the history of ship building and seafaring of the Old worl
Explainable Deep Learning to Classify Royal Navy Ships
No full textWe research how deep learning convolutional neural networks can be used to automatically classify the unique data set of black-and-white naval ships images from the Wright and Logan photographic collection held by the National Museum of the Royal Navy. We contrast various types of deep learning methods: pretrained models such as ConvNeXt, ResNet and EfficientNet, and ConvMixer. We also thoroughly investigate the impact of data preprocessing and externally obtained images on model performance. Finally, we research how the models estimated can be made transparent using visually appealing interpretability techniques such as Grad-CAM. We find that ConvNeXt has the best performance for our data set achieving an accuracy of 79.62% for 0-notch classification and an impressive 94.86% for 1-notch classification. The results indicate the importance of appropriate image preprocessing. Image segmentation combined with soft augmentation significantly contributes to model performance. We consider this research to be original in several aspects. Notably, it distinguishes itself through the uniqueness of the acquired dataset. Additionally, its distinctiveness extends to the analytical modeling pipeline, which encompasses a comprehensive range of modeling steps, including data preprocessing (incorporating external data, image segmentation, and image augmentation) and the use of deep learning techniques such as ConvNeXt, ResNet, EfficientNet, and ConvMixer. Furthermore, the research employs explanatory tools like Grad-CAM to enhance model interpretability and usability. We believe the proposed methodology offers lots of potential for documenting historic image collections.</p
Deep Sea Archaeological Survey in the Black Sea – Robotic documentation of 2,500 years of human Seafaring
No full textBetween 2015 and 2017 the Black Sea Maritime Archaeology Project (Black Sea MAP) discovered and recorded 65 shipwreck sites dating from the 5th/4th Century BC to the 19th Century AD in the Bulgarian EEZ. Using state-of-the-art remotely operated vehicles to survey the seabed, the team captured more than 250,000 high-definition (HD) photographs; hundreds of hours of ultra-high (UHD) video together with acoustic bathymetric, laser bathymetric, side-scan sonar and seismic data. The wrecks were located in depths from 40 to 2,200 metres – those shipwrecks in the deeper range presented extraordinary archaeological preservation due to the Black Sea’s anoxic conditions. This paper will introduce the methods used based on a wide range of deep-sea optic and acoustic survey techniques to create 3D and pseudo 4D models of the shipwrecks
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
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