Proton induced X-ray emission (PIXE) is a well-known method for elemental analysis in many different specimens for various applied studies. In this paper, we report an application of PIXE analysis for a series of ancient Chinese coins from the Tang Dynasty to the Ming Dynasty (AD 618-1679). Ninety-six PIXE spectra were obtained from forty-eight samples of the ancient coins with the use of a Ge(...

The coin weighing problem is the following: Given n coins for which m of them are counterfeit with the same weight. The problem is to detect the counterfeit coins with minimal number of weighings. This problem has many applications in compressed sensing, multiple access adder channels, etc. This problem was solved when m is unknown. An old optimal non-adaptive polynomial time algorithm of Linds...

Background: A set of silver coins from the collection of Déri Museum Debrecen (Hungary) was examined by X-ray fluorescent elemental analysis with the aim to assign the coins to different groups with the best possible precision based on the acquired chemical information and to build models, which arrange the coins according to their historical periods. Results: Principal component analysis, line...

Roman coins play an important role to understand the Roman empire because they convey rich information about key historical events of the time. The ancient Roman coins were widely used to announce the achievements of Roman emperors to the public. They also served to spread messages of changing policies or merits through the empire. By engraving portraits on the coins, the Roman emperors also co...

Blet is a puzzle. One starts with an even number of coins, laid out in a circle. At first, the coins are laid out with heads and tails alternating (HTHTHT. . .HT). Each turn, you are allowed to take three consecutive coins that show tails-heads-tails and flip them over, getting heads-tails-heads. This increases the total number of heads by one. You may do the opposite, flipping a heads-tails-he...

The introduction of the euro has revived interest in the risk of nickel allergy due to the handling of coins. In the present work, the transfer of metallic contamination during the manipulation of coins is examined by means of leaching experiments and manipulation tests. It is shown that pre-existing metallic species present on the surface of the coins are the major source of contamination duri...

Fundamental part of a numismatist’s work is the classifi cation of coins according to standard reference books. For this application, image processing techniques like Image Enhancement, Image Segmentation and Optical Character Recognition (OCR) are investigated. The recently started European project COINS combines these two research areas by developing a vision based system for automated coin r...

Many of the pious bequest policies (Vaghf) !supportFootnotes]-->[1] at present time are denominated by old or ancient coins, the present value of which is not well known. Therefore, fixing the annual custodian fee for Vaghf is quite difficult. Moreover, the difficulty of evaluation of the present value of the dowry the husband has to pay to the bride after the marriage (Mahr) !supportFootno...

We discuss the problem of maximizing the number of coins, for which, using just n weighings, one can tell whether all of them are of the same weight or not, under condition that the weights of the coins are generic. The first purpose of the paper is to show the connection between this problem and a problem in lattice geometry. Using this approach, we are able to establish an upper bound on the ...

We develop a model of commodity money and use it to analyze the following two questions motivated by issues in monetary history: What are the conditions under which Gresham's Law holds? And, what are the mechanics of a debasement (lowering the metallic content of coins)? The model contains light and heavy coins, imperfect information, and prices determined via bilateral bargaining. There are eq...