Search Results (12)

Imitative coinage is understood to be any currency issued outside of the official known coin series. This currency could have been issued by individuals or state agents, and its main function was not profit, but rather it responded to currency shortages and acted as a currency of necessity. It must be distinguished from the currency itself, which had a lucrative intent on the part of the issuers. Coin imitation was a phenomenon that occurred during various chronological periods throughout the Roman Imperial era, essentially linked to historical events that caused a monetary shortage. This refers to a phenomenon where coinage not issued by the official authority was introduced into circulation and utilized in commercial exchanges of various kinds, a fact that can be demonstrated archaeologically. Imitative coinage can be detected through detailed numismatic studies, revealing variability in stylistic elements, as well as physical characteristics (such as weight or diameter) when compared to the official issue. Coin imitation should not be confused with monetary counterfeiting, as its intention was not to profit the unofficial issuer, but rather to facilitate daily commercial exchanges. Even so, the characteristics of both can be similar in some cases, which can make it difficult to assign them to one type or the other. The imitative pieces, primarily in bronze types though not limited to them, played a highly significant role in maintaining Roman economic systems during periods of decline in official currency. Full article

Our article presents a holistic analysis aimed at discerning patterns from ancient–modern comparative contexts of malaria. The article’s interdisciplinary and consilient methodology is drawn from a range of disciplines: the humanities and social sciences, medical knowledge (particularly epidemiology and pathology), molecular phylogenetics, demography, archaeology, paleopathology, numismatics, complex systems theory, etc. The article begins with a detailed exploration of a 463 BCE epidemic event that likely marked the, ultimately transformative, debut of P. falciparum evolutionary lineage malaria for ancient Roman civilization. It is important to note that the concept of evolutionary lineage is defined herein as a sequence of organisms, descended from a common ancestor and culminating, for the present at least, in the form existing currently. An interdisciplinary retrospective diagnosis methodology is utilized to establish, with what we believe to be a high degree of probability, a conclusion that effectively marks the beginning point for the ancient side of our comparative example. The deep interdisciplinary/historical methods used to elucidate the ancient side of the disease equation both lead to a clear conclusion and suggest potential modern analogies or even “prophecies.” These are used to highlight the threats emanating from the current spread of zoonotic P. knowlesi malaria in Southeast Asia. The article also utilizes six broader holistic and interdisciplinary factors in its contextual and comparative analysis: (A) political, military and security contexts; (B) the effects of cultural perceptions; (C) the role of climate and climate change; (D) additional anthropogenic environmental factors; (E) perceptions, practices and capabilities of prevailing medical systems and (F) holistic underlying states of the health of affected populations. Full article

Non-destructive, specular laser reflectometry, an industrially used and easily accessible method, is adapted in numismatic research to the inspection of coins of the Gallic Roman Empire with the objective of the allocation of mints and/or the identification of different minting techniques. For this purpose, the laser-reflectometric fingerprints of three series of coins each consisting of five antoniniani (or radiates) of the Gallic Roman Empire originating from two mints—Trier and Cologne—are systematically determined, analyzed and correlated with the corresponding XRF element analysis. The results show that the use of an inexpensive red-emitting laser system (wavelength 632.8 nm) with a beam diameter $d<0.5$ mm and a sample mount that can be adapted to the individual shape and thickness of the coins leads to signal intensities that can be systematically recorded over a large angular range with a very good signal-to-noise ratio (SNR $>10$). While the signals cannot be used to assign individual coins to mints, we discuss the possibility of a statistical analysis. Although each coin set consists of only five samples and thus requires further study, the results here suggest that the sets can be distinguished from each other, that there is a correlation to the silver concentration and that it is possible to estimate the refractive index n. Full article

The numismatic collection in the Auckland War Memorial Museum Tāmaki Paenga Hira, Auckland, New Zealand, is an extensive although little-known collection. As part of a wider rehousing project for the coins, a trial was conducted to rehouse the Greek and Roman coins to establish the best storage and analysis practices. Records were also created or updated during this process to make them visible online and enable their use in future research. Best practice standards include handling and measurement practice, retaining all existing information about the collection, and, where possible, reuniting coins with their acquisition information. The project’s end goal is to create populated records in the museum database (Vernon) for the entire numismatic collection, either through updating existing records, creating records using available acquisition information, or creating records with temporary numbers where that information has been lost. This report gives a brief history of the collection and the rehousing process and suggests future research avenues. Full article

We report here the results of a multi-analytical approach to characterize twelve Roman coins dating from the third century B.C. to fifth century A.D. that were found in the surroundings of Rome and for which the year of minting is determined by numismatic analysis. The coins were studied using SEM-EDS, EMPA, XRD, and FTIR techniques, enabling semi-quantitative and quantitative determinations of the chemical and mineralogical composition of the alloys and corrosion products. SEM-EDS analyses highlighted the occurrence of corrosion products on the surfaces and wide chemical variations due to selective enrichment or depletions of the alloying metals. The EMP analyses showed that three of the twelve coins are made of copper (1), one is a copper–tin alloy (2), five are copper–tin–lead alloys with elements in different proportions (3), two are copper–lead alloys (4), and another one is a subaerata coin (5). In addition, the physical parameters of the coins, i.e., density, weight, and diameters, were measured to have an overall characterization. Full article

Ancient numismatics, the study of ancient coins, has in recent years become an attractive domain for the application of computer vision and machine learning. Though rich in research problems, the predominant focus in this area to date has been on the task of attributing a coin from an image, that is of identifying its issue. This may be considered the cardinal problem in the field and it continues to challenge automatic methods. In the present paper, we address a number of limitations of previous work. Firstly, the existing methods approach the problem as a classification task. As such, they are unable to deal with classes with no or few exemplars (which would be most, given over 50,000 issues of Roman Imperial coins alone), and require retraining when exemplars of a new class become available. Hence, rather than seeking to learn a representation that distinguishes a particular class from all the others, herein we seek a representation that is overall best at distinguishing classes from one another, thus relinquishing the demand for exemplars of any specific class. This leads to our adoption of the paradigm of pairwise coin matching by issue, rather than the usual classification paradigm, and the specific solution we propose in the form of a Siamese neural network. Furthermore, while adopting deep learning, motivated by its successes in the field and its unchallenged superiority over classical computer vision approaches, we also seek to leverage the advantages that transformers have over the previously employed convolutional neural networks, and in particular their non-local attention mechanisms, which ought to be particularly useful in ancient coin analysis by associating semantically but not visually related distal elements of a coin’s design. Evaluated on a large data corpus of 14,820 images and 7605 issues, using transfer learning and only a small training set of 542 images of 24 issues, our Double Siamese ViT model is shown to surpass the state of the art by a large margin, achieving an overall accuracy of 81%. Moreover, our further investigation of the results shows that the majority of the method’s errors are unrelated to the intrinsic aspects of the algorithm itself, but are rather a consequence of unclean data, which is a problem that can be easily addressed in practice by simple pre-processing and quality checking. Full article

This study aims to explore the connection between religious and military spheres in Constantinian propaganda. The extensive use of propaganda and the notorious public discourse which involves the dynamics of power during Late Antiquity show how religion and the military played a key role. This principle reaches a singular meaning in the case of emperor Constantine I. To this extent, this paper considers several kinds of sources, which include legal, literary, and numismatic, among others. An analysis of the political uses of imperial constitutions by the emperor (especially CTh 7.20.2) can be of particular interest in order to address the ideas of self-representation and the politics of legitimation. Ultimately, the paper highlights the importance of imperial propaganda in Later Roman society, as well as the transformations in Constantine’s public discourse, where the connection between army and religion shows an evolution from the previous ways of understanding imperial power and where the bond of the ruler with a supreme divinity is a central issue. Full article

This study stems from the need for numismatics to establish whether there may be relationships between a group of 103 bronze coins from the Roman era found in archaeological excavations on the Cesén Mountain (Treviso, Italy) and a group of 117 coins kept at the Museum of Natural History and Archaeology in Montebelluna (Treviso, Italy). The chemists were delivered six coins with neither pre-agreements nor further information on the origin of the coins. Therefore, the request was to hypothetically assign the coins to the two groups on the basis of similarities and differences in their surface composition. Only non-destructive analytical techniques were allowed to be used to characterize the surface of the six coins taken blindly from the two sets. The elemental analysis of each coins’ surface was carried out by µ-XRF. To better observe the morphology of the coins’ surfaces, SEM-EDS was used. Compounds covering the coins coming from both corrosion processes (patinas) and the deposition of soil encrustations were also analyzed by means of the FTIR-ATR technique. The molecular analysis confirmed the presence of silico-aluminate minerals on some coins, unequivocally indicating a provenance from clayey soil. Some soil samples, collected from the archaeological site of interest, were analyzed to verify whether the encrusted layer on coins could contain chemical components compatible with them. This result, together with the chemical and morphological investigations, led us to subdivide the six target coins into two groups. The first group is made up of two coins coming from the set of coins from excavation (found in the subsoil) and from the set from open air finds (coins found in the top layer of the soil). The second group is made up of four coins that are devoid of characteristics corresponding to exposure to soil contact for long periods of time and, moreover, their surface compounds could suggest a different provenance. The analytical results of this study made it possible to correctly assign all six coins to the two groups of finds and support numismatics, which was unconvinced in considering all coins to come from the same finding site only on the basis of archaeological documentations. Full article

Automatic ancient Roman coin analysis only recently emerged as a topic of computer science research. Nevertheless, owing to its ever-increasing popularity, the field is already reaching a certain degree of maturity, as witnessed by a substantial publication output in the last decade. At the same time, it is becoming evident that research progress is being limited by a somewhat veering direction of effort and the lack of a coherent framework which facilitates the acquisition and dissemination of robust, repeatable, and rigorous evidence. Thus, in the present article, we seek to address several associated challenges. To start with, (i) we provide a first overview and discussion of different challenges in the field, some of which have been scarcely investigated to date, and others which have hitherto been unrecognized and unaddressed. Secondly, (ii) we introduce the first data set, carefully curated and collected for the purpose of facilitating methodological evaluation of algorithms and, specifically, the effects of coin preservation grades on the performance of automatic methods. Indeed, until now, only one published work at all recognized the need for this kind of analysis, which, to any numismatist, would be a trivially obvious fact. We also discuss a wide range of considerations which had to be taken into account in collecting this corpus, explain our decisions, and describe its content in detail. Briefly, the data set comprises 100 different coin issues, all with multiple examples in Fine, Very Fine, and Extremely Fine conditions, giving a total of over 650 different specimens. These correspond to 44 issuing authorities and span the time period of approximately 300 years (from 27 BC until 244 AD). In summary, the present article should be an invaluable resource to researchers in the field, and we encourage the community to adopt the collected corpus, freely available for research purposes, as a standard evaluation benchmark. Full article

We propose an image-based class retrieval system for ancient Roman Republican coins that can be instrumental in various archaeological applications such as museums, Numismatics study, and even online auctions websites. For such applications, the aim is not only classification of a given coin, but also the retrieval of its information from standard reference book. Such classification and information retrieval is performed by our proposed system via a user friendly graphical user interface (GUI). The query coin image gets matched with exemplar images of each coin class stored in the database. The retrieved coin classes are then displayed in the GUI along with their descriptions from a reference book. However, it is highly impractical to match a query image with each of the class exemplar images as there are 10 exemplar images for each of the 60 coin classes. Similarly, displaying all the retrieved coin classes and their respective information in the GUI will cause user inconvenience. Consequently, to avoid such brute-force matching, we incrementally vary the number of matches per class to find the least matches attaining the maximum classification accuracy. In a similar manner, we also extend the search space for coin class to find the minimal number of retrieved classes that achieve maximum classification accuracy. On the current dataset, our system successfully attains a classification accuracy of 99% for five matches per class such that the top ten retrieved classes are considered. As a result, the computational complexity is reduced by matching the query image with only half of the exemplar images per class. In addition, displaying the top 10 retrieved classes is far more convenient than displaying all 60 classes. Full article

Ancient numismatics, that is, the study of ancient currencies (predominantly coins), is an interesting domain for the application of computer vision and machine learning, and has been receiving an increasing amount of attention in recent years. Notwithstanding the number of articles published on the topic, the variety of different methodological approaches described, and the mounting realisation that the relevant problems in the field are most challenging indeed, all research to date has entirely ignored one specific, readily accessible modality: colour. Invariably, colour is discarded and images of coins treated as being greyscale. The present article is the first one to question this decision (and indeed, it is a decision). We discuss the reasons behind the said choice, present a case why it ought to be reexamined, and in turn investigate the issue for the first time in the published literature. Specifically, we propose two new colour-based representations specifically designed with the aim of being applied to ancient coin analysis, and argue why it is sensible to employ them in the first stages of the classification process as a means of drastically reducing the initially enormous number of classes involved in type matching ancient coins (tens of thousands, just for Ancient Roman Imperial coins). Furthermore, we introduce a new data set collected with the specific aim of denomination-based categorisation of ancient coins, where we hypothesised colour could be of potential use, and evaluate the proposed representations. Lastly, we report surprisingly successful performances which goes further than confirming our hypothesis—rather, they convincingly demonstrate a much higher relevant information content carried by colour than even we expected. Thus we trust that our findings will be noted by others in the field and that more attention and further research will be devoted to the use of colour in automatic ancient coin analysis. Full article

In recent years, a range of problems under the broad umbrella of computer vision based analysis of ancient coins have been attracting an increasing amount of attention. Notwithstanding this research effort, the results achieved by the state of the art in published literature remain poor and far from sufficiently well performing for any practical purpose. In the present paper we present a series of contributions which we believe will benefit the interested community. We explain that the approach of visual matching of coins, universally adopted in existing published papers on the topic, is not of practical interest because the number of ancient coin types exceeds by far the number of those types which have been imaged, be it in digital form (e.g., online) or otherwise (traditional film, in print, etc.). Rather, we argue that the focus should be on understanding the semantic content of coins. Hence, we describe a novel approach—to first extract semantic concepts from real-world multimodal input and associate them with their corresponding coin images, and then to train a convolutional neural network to learn the appearance of these concepts. On a real-world data set, we demonstrate highly promising results, correctly identifying a range of visual elements on unseen coins with up to 84% accuracy. Full article