283 research outputs found

    Early Medieval hillforts and the possibilities of their investigation by geophysical methods

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    This contribution deals with research into early medieval hillforts by means of geophysical methods. Comparison of archaeological sources and results of geophysical measurements was used for the analysis of some previous and more recent results, while future possibilities of research are outlined as well. In geographical terms, the article focuses on the north regions of the Central Danubian Basin, particularly Moravia and western Slovakia. The research is aimed at integral sections of Great Moravia that was forming in this territory in the 9th century, whereas the majority of local hillforts are connected with its existence. Archaeology of the neighbouring regions in the period of the early Middle Ages is in many respects similar to that of the Central Danubian Basin, and the general outcomes can thus be extended to the whole of Central Europe

    Archeologický výzkum raně středověkého sídliště Kostice – Zadní hrúd v letech 2009–2011

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    V článku jsou představeny výsledky archeologického výzkumu lokality Kostice – Zadní hrúd, který proběhl v letech 2009 až 2011. Zkoumaná lokalita, vzdušnou čarou vzdálená 1,5 km od středu blízkého velkomoravského centra na Pohansku, se rozkládá u okraje nivy řeky Dyje na nevýrazné písčité duně. Konkrétní místo terénního odkryvu bylo vybráno pomocí predikčního modelování a na základě důkladné prospekce. Celkově byla odkryta plocha 2405 m2, na níž bylo prozkoumáno 160 zahloubených sídlištních objektů a dva hroby z různých období. Většina nálezů souvisela s raným středověkem, těžiště osídlení spadá do 10. až 12. století. Zdejší sídliště patřilo v 9. stol. k subsistenční základně rozlehlé velkomoravské aglomerace na Pohansku a po jeho zániku se transformovalo v řemeslně-agrární a obchodní centrum druhého řádu, tzv. trhovou ves. Mimořádně významné jsou nálezy mincí, skládacích vážek, kupeckých závaží a pozdně nomádských třmenů.The article presents the results of the archaeological excavation of the Kostice – Zadní hrúd site, conducted in 2009–2011. The investigated site, 1.5 km from the heart of the nearby Great Moravian centre at Pohansko, lies at the edge of the Dyje (Thaya) River floodplain on a nondescript sand dune. A total of 160 sunken features and two graves from various periods were investigated over the excavated area of 2,405 m2. The majority of finds were from the Early Middle Ages, with the peak of settlement falling between the tenth and twelfth centuries. In the ninth century, the local settlement was part of the subsistence base for the vast Great Moravian agglomeration at Pohansko; following the demise of Pohansko, the Kostice – Zadní hrúd settlement was transformed into a craft-agrarian and trade centre of the second level. Finds of coins, balance scales, merchants’ weights and late nomadic stirrups are of extraordinary importance

    High-order Discretization of a Gyrokinetic Vlasov Model in Edge Plasma Geometry

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    We present a high-order spatial discretization of a continuum gyrokinetic Vlasov model in axisymmetric tokamak edge plasma geometries. Such models describe the phase space advection of plasma species distribution functions in the absence of collisions. The gyrokinetic model is posed in a four-dimensional phase space, upon which a grid is imposed when discretized. To mitigate the computational cost associated with high-dimensional grids, we employ a high-order discretization to reduce the grid size needed to achieve a given level of accuracy relative to lower-order methods. Strong anisotropy induced by the magnetic field motivates the use of mapped coordinate grids aligned with magnetic flux surfaces. The natural partitioning of the edge geometry by the separatrix between the closed and open field line regions leads to the consideration of multiple mapped blocks, in what is known as a mapped multiblock (MMB) approach. We describe the specialization of a more general formalism that we have developed for the construction of high-order, finite-volume discretizations on MMB grids, yielding the accurate evaluation of the gyrokinetic Vlasov operator, the metric factors resulting from the MMB coordinate mappings, and the interaction of blocks at adjacent boundaries. Our conservative formulation of the gyrokinetic Vlasov model incorporates the fact that the phase space velocity has zero divergence, which must be preserved discretely to avoid truncation error accumulation. We describe an approach for the discrete evaluation of the gyrokinetic phase space velocity that preserves the divergence-free property to machine precision

    Magnetic survey in the process of large-scale construction sites

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    Archaeogeophysical prospection is necessary when planning large constructions. Motorized magnetometry systems offer an effective method to identify archaeology prior the construction. A sufficiently large area must be surveyed to estimate the archaeological potential correctly

    Core Ironclad

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    Core Ironclad is a core calculus that models the salient features of Ironclad C++, a library-augmented type-safe subset of C++. We give an overview of the language including its definition and key design points. We then prove type safety for the language and use that result to show that the pointer lifetime invariant, a key property of Ironclad C++, holds within the system

    Investigating the complex story of one ditch — A multidisciplinary study of ditch infill provides insight into the spatial organisation within the oppidum of Bibracte (Burgundy, France)

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    Seemingly empty spaces in various archaeological settings have left many unanswered questions. This paper focuses on the appearance, maintenance and possible function of a large empty area situated at the summit plateau of the Iron Age oppidum Bibracte in France. Multidisciplinary research of the infill of the ditch that delimited this area in the 1st century BC has provided evidence on the primary function and the formation processes of the structure itself, and for the reconstruction of the appearance, maintenance and function of the area it enclosed. The results allow us to gain insight into a variety of topics, including the role of trees, hygiene measures and waste management strategies at this urbanised hilltop centre. This paper demonstrates that multi-proxy analyses provide detailed insight into the function of archaeological features in a local environmental context and the potential of such approaches in archaeology.U domněle prázdných(nezastavěných) míst v archeologickém kontextu je řada nezodpovězených otázek. Článek se zaměřuje na vzhled, způsob udržování a možnou funkci velkého prázdného prostoru v době železné v rámci vrcholového plateau oppida Bibracte ve Francii. Multidisciplinární přístup k výzkumu výplně příkopu, který tento prostor vymezoval v 1. století př. Kr., poskytl doklady o primárním využití a vzniku výplně v příkopu a dále k rekonstrukci vzhledu, managementu a funkce území, které jej obklopovalo. Výsledky nám umožňují vhled do řady témat, včetně role stromů, úrovně hygieny a nakládání s odpadem v urbanizovaném prostředí oppida. Článek prokazuje důležitost multi-proxy přístupu pro řešení funkce archeologických objektů v lokálním environmentálním kontextu a potenciál tohoto přístupu v archeologii

    Node similarity within subgraphs of protein interaction networks

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    We propose a biologically motivated quantity, twinness, to evaluate local similarity between nodes in a network. The twinness of a pair of nodes is the number of connected, labeled subgraphs of size n in which the two nodes possess identical neighbours. The graph animal algorithm is used to estimate twinness for each pair of nodes (for subgraph sizes n=4 to n=12) in four different protein interaction networks (PINs). These include an Escherichia coli PIN and three Saccharomyces cerevisiae PINs -- each obtained using state-of-the-art high throughput methods. In almost all cases, the average twinness of node pairs is vastly higher than expected from a null model obtained by switching links. For all n, we observe a difference in the ratio of type A twins (which are unlinked pairs) to type B twins (which are linked pairs) distinguishing the prokaryote E. coli from the eukaryote S. cerevisiae. Interaction similarity is expected due to gene duplication, and whole genome duplication paralogues in S. cerevisiae have been reported to co-cluster into the same complexes. Indeed, we find that these paralogous proteins are over-represented as twins compared to pairs chosen at random. These results indicate that twinness can detect ancestral relationships from currently available PIN data.Comment: 10 pages, 5 figures. Edited for typos, clarity, figures improved for readabilit

    Geophysical survey at archaeological sites in northeastern Syria

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    From August 25 to September 4, 2008, geophysical surveys were carried out at the Neolithic, Chalcolithic, Bronze and Iron Age tell- and non-tell settlements in the Khabur region in Northeastern Syria (Syrian-Polish-Czech expedition) (Fig. 1). Four sites were prospected: Tell Arbid Abyad, Tell Arbid (West-hill), Khirbet Shane, Khirbet Bezi. The Scintrex Navmag SM-5 – Caesium Magnetometer was used for the measurement of the vertical gradient of the local magnetic field. The measurement resoluti..

    scite: A Smart Citation Index that Displays the Context of Citations and Classifies Their Intent Using Deep Learning

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    Citation indices are tools used by the academic community for research and research evaluation that aggregate scientific literature output and measure impact by collating citation counts. Citation indices help measure the interconnections between scientific papers but fall short because they fail to communicate contextual information about a citation. The use of citations in research evaluation without consideration of context can be problematic because a citation that presents contrasting evidence to a paper is treated the same as a citation that presents supporting evidence. To solve this problem, we have used machine learning, traditional document ingestion methods, and a network of researchers to develop a “smart citation index” called scite, which categorizes citations based on context. Scite shows how a citation was used by displaying the surrounding textual context from the citing paper and a classification from our deep learning model that indicates whether the statement provides supporting or contrasting evidence for a referenced work, or simply mentions it. Scite has been developed by analyzing over 25 million full-text scientific articles and currently has a database of more than 880 million classified citation statements. Here we describe how scite works and how it can be used to further research and research evaluation

    Automatic Recognition, Segmentation, and Sex Assignment of Nocturnal Asthmatic Coughs and Cough Epochs in Smartphone Audio Recordings: Observational Field Study

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    Background: Asthma is one of the most prevalent chronic respiratory diseases. Despite increased investment in treatment, little progress has been made in the early recognition and treatment of asthma exacerbations over the last decade. Nocturnal cough monitoring may provide an opportunity to identify patients at risk for imminent exacerbations. Recently developed approaches enable smartphone-based cough monitoring. These approaches, however, have not undergone longitudinal overnight testing nor have they been specifically evaluated in the context of asthma. Also, the problem of distinguishing partner coughs from patient coughs when two or more people are sleeping in the same room using contact-free audio recordings remains unsolved. Objective: The objective of this study was to evaluate the automatic recognition and segmentation of nocturnal asthmatic coughs and cough epochs in smartphone-based audio recordings that were collected in the field. We also aimed to distinguish partner coughs from patient coughs in contact-free audio recordings by classifying coughs based on sex. Methods: We used a convolutional neural network model that we had developed in previous work for automated cough recognition. We further used techniques (such as ensemble learning, minibatch balancing, and thresholding) to address the imbalance in the data set. We evaluated the classifier in a classification task and a segmentation task. The cough-recognition classifier served as the basis for the cough-segmentation classifier from continuous audio recordings. We compared automated cough and cough-epoch counts to human-annotated cough and cough-epoch counts. We employed Gaussian mixture models to build a classifier for cough and cough-epoch signals based on sex. Results: We recorded audio data from 94 adults with asthma (overall: mean 43 years; SD 16 years; female: 54/94, 57%; male 40/94, 43%). Audio data were recorded by each participant in their everyday environment using a smartphone placed next to their bed; recordings were made over a period of 28 nights. Out of 704,697 sounds, we identified 30,304 sounds as coughs. A total of 26,166 coughs occurred without a 2-second pause between coughs, yielding 8238 cough epochs. The ensemble classifier performed well with a Matthews correlation coefficient of 92% in a pure classification task and achieved comparable cough counts to that of human annotators in the segmentation of coughing. The count difference between automated and human-annotated coughs was a mean –0.1 (95% CI –12.11, 11.91) coughs. The count difference between automated and human-annotated cough epochs was a mean 0.24 (95% CI –3.67, 4.15) cough epochs. The Gaussian mixture model cough epoch–based sex classification performed best yielding an accuracy of 83%. Conclusions: Our study showed longitudinal nocturnal cough and cough-epoch recognition from nightly recorded smartphone-based audio from adults with asthma. The model distinguishes partner cough from patient cough in contact-free recordings by identifying cough and cough-epoch signals that correspond to the sex of the patient. This research represents a step towards enabling passive and scalable cough monitoring for adults with asthma
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