8 research outputs found
A ‘match–no match‘ numerical and graphical kernel density approach to interpreting lead isotope signatures of ancient artefacts
No full textsponsorship: The authors gratefully acknowledge the financial support of the KU Leuven Research Council (Bijzonder Onderzoeksfonds project number C14/19/060). The paper greatly benefited from a Visiting Fellowship by Patrick Degryse at All Souls College, Oxford. (KU Leuven Research Council|C14/19/060, All Souls College, Oxford)status: Publishe
Dataset of lead isotope ratios of copper ores.
No full textThis dataset was compiled from the literature. All samples analyzed prior to 1980 are excluded, due to poorer precision before that date. The ores have been placed in groups corresponding to countries or important regions. In most papers the ratios 208Pb/206Pb, 207Pb/206Pb and 206Pb/204Pb were given. The ratios 208Pb/204Pb and 207Pb/204Pb shown have been calculated from the other values. All samples which were published with only two isotope ratios are excluded
Dataset of lead isotope ratios of lead ores.
No full textThis database was compiled from the literature.
All samples analysed prior to 1980 are excluded, due to poorer precision before that date.
The ores have been placed in groups corresponding to countries or important regions.
In most papers the ratios 208Pb/206Pb, 207Pb/206Pb and 206Pb/204Pb were given. The ratios 208Pb/204Pb and 207Pb/204Pb shown have been calculated from the other values.
All samples which were published with only two isotope ratios are excluded
Towards Flow Propagation Modeling with System Dynamics? Application on the Ring of Brussels
No full textEngineering and Policy AnalysisPolicy AnalysisTechnology, Policy and Managemen
Provenancing ancient materials with lead isotopes:overlap uncovered
No full textLead isotope analysis has been used to provenance metals such as lead, silver and bronze for many decades. Different approaches to interpret lead isotope ratios were proposed, and various limitations of the method have been discussed and addressed. Overlap in composition between different possible ore sources is always mentioned as a major limitation in lead isotope studies. However, it has never been comprehensively studied using a multivariate statistical approach. In this paper, the kernel density estimation (KDE) approach previously proposed by the authors is applied to calculate overlap between possible ore source regions. Firstly, the copper and lead ores of the same regions are compared, to assess if they are consistent and thus can be combined to increase sample size for provenance studies. Secondly, the pair-wise overlap between all the mining regions is calculated to determine if the distinction can actually be made between those ore fields. The use of one-dimensional KDE’s is very effective for calculation and assessment of the overlap between ore sources. This study argues that merging the lead and copper ore data might increase the reliability of a region’s KDE’s in most cases, but the overlap should be assessed beforehand. Furthermore, the study provides useful tools to verify for every pair of possible ore sources if it is theoretically possible to discriminate between them, and to what extent.</p
Transformative copper metallurgy in Chalcolithic Cyprus: a reappraisal
No full textsponsorship: We wish to thank the Royal Commission for AlUla for its support. We extend special thanks to the Governor, His Highness Prince Badr bin Abdullah bin Mohammad bin Farhan Al Saud; CEO, Amr AlMadani; and the Director of Archaeology and Cultural Heritage Research, Rebecca Foote. We would like to acknowledge the assistance of Laura Strolin, Jamie Quartermaine, Wael Abu-Azizeh and Huw Groucutt. Finally, we thank David Kennedy, who first introduced us to mustatils and whose exemplary work is the reason this project exists. (Royal Commission for AlUla)status: Publishe
ИЗМЕРЕНИЕ ФИНАНСОВОГО ЗАРАЖЕНИЯ НА ПРИМЕРЕ МОДЕЛИРОВАНИЯ РИСКА БАНКОВСКОГО ДЕФОЛТА
No full textThe paper focuses on the methods used for measuring financial contagion through simulation of the bank default risk viewed as a trigger event. Systemic risk and financial contagion as well as the mechanism which enables system risk implementation are considered taking into account such aspects of financial contagion as the existence of overlapping channels of risk transfer, interbank and independent bank levels, and feedback loops impact. The methodology for analyzing financial contagion outcomes is based on the approach allowing for the latent factor. The author examines the methodology while applied for simulating bank default risk. Basic approaches to measure financial contagion in time and structural perspectives have been suggested. An important aspect of the financial effect of contagion is the fact that it occurs in the dynamics which implies a more significant impact than might initially be expected. A weak banking system may have a negative impact on the state as the subsidization of one bank may increase the risk to the whole banking system, which; in turn; will reduce the effectiveness of subsidies for chosen bank, etc. The lasting effect generates a reverse effect loop of financial contagion. The final part of the article shows the similar channels which eventually may provoke financial contagion in Russia.В статье рассматриваются методы измерения эффекта финансового заражения на примере моделирования риска банковского дефолта как события триггера. Системный риск и финансовое заражение, механизм реализации системного риска описаны с учетом таких особенностей эффекта финансового заражения, как существование накладывающихся каналов передачи риска, межбанковского и суверенно-банковского уровней, а также действия петель обратного влияния. Методология анализа эффекта финансового заражения, основанная на подходе анализа с учетом латентного фактора, разобрана на примере моделирования риска банковского дефолта. Предложены базовые подходы к измерению финансового заражения с временно́й и структурной перспективой анализа. Важный аспект эффекта финансового заражения - то, что оно происходит в динамике, из чего следуют более значимые последствия, чем могли бы изначально ожидаться. Слабая банковская система может негативно влиять на государство так, как субсидирование одного банка может повысить риск в остальной банковской системе, что снизит эффективность субсидирования выбранного банка и т.д. Такой продолжительный эффект порождает петлю обратного влияния эффекта финансового заражения. В заключительной части статьи приведены аналогии существования каналов финансового заражении в России
