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Each year, National Coin Week, the third week in April, brings together coin enthusiasts in honor of one of the world's oldest and most popular pastimes. Numismatics, the study and collecting of coins, draws a large following with a variety of interests. Some have specific interests, such as primitive monies, error coins, counterfeits, or commemoratives. Others study coins for the insight they offer into art, royalty, military history, or politics and economics. Regardless of the reason, coin collectors have an important role. As precious metals disappear from coins, and coin usage decreases, the history represented by coins may become the province of the collector.

The purpose of this paper is to form copper coin-embedded printed circuit board (PCB) for high heat dissipation.

Manufacturing optimization of copper coin-embedded PCB involved in the design and treatment of copper coin, resin flush removal and flatness control. Thermal simulation was used to investigate the effect of copper coin on heat dissipation of PCB products. Lead-free reflow soldering and thrust tests were used to characterize the reliable performance of copper coin-embedded PCB.

The copper coin-embedded PCB had good agreement with resin flush removal and flatness control. Thermal simulation results indicated that copper coin could significantly enhance the heat-dissipation rate by means of a direct contact with the high-power integrated circuit chip. The copper coin-embedded PCB exhibited a reliable structure capable of withstanding high-temperature reflow soldering and high thrust testing.

The use of a copper coin-embedded PCB could lead to higher heat dissipation for the stable performance of high-power electronic components. The copper coin-embedded method could have important potential for improving the design for heat dissipation in the PCB industry.

The defective coin problem involves the identification of a defective coin, if any, and ascertaining the nature of the defect (heavier/lighter) from a set of coins containing at the most one defective coin, using an equal‐arm‐pan‐balance. An algorithmic analysis of the problem is considered. The solution strategy to minimise the number of weighings required to detect the defective coin is based on a problem reduction approach involving successive decomposition of the problem into subproblems until it is trivially solved. The algorithm is capable of generating all possible optimal solutions.

The purpose of this paper is to investigate the microstructures, slag inclusions, morphology and composition of ancient Chinese iron coins exhumed from Emei Mountain and Baoji after 818‐966 years of being imbedded underground.

Metallography, scanning electron microscopy, energy dispersive spectrometry, X‐ray photoelectron spectrometry and Fourier transform infrared spectroscopy were employed.

The results showed that archaeological coins exhibited characteristics of a typical hypoeutectic white cast iron, with slag inclusions of FeS strips and phosphate. Porous or hexagonal platey corrosion products were discovered on the archaeological iron coin, which were mainly identified as Fe₂O₃, FeOOH, Fe_x(OH)_1−xCO₃ and Fe_x(OH)_1−xSO₄. The possible corrosion mechanisms for the iron coins were discussed based on the corrosion products.

This study revealed the characterization of corrosion products on archaeological iron coins and may provide guidance for the preservation of archaeological iron.

This paper aims to explain the architecture and design choices of the exchange. Lykke is a FinTech company based in Zurich that has launched the global marketplace for all asset classes and instruments digitized on the blockchain. The authors discuss how the exchange will evolve over time. They explore the macroeconomic benefits of the new blockchain technology. The Lykke exchange is compatible with any type of public blockchain.

The authors present the architecture of an exchange for colored coins. By colored coins, they mean issuer-backed securities on the Bitcoin blockchain. Orders are collected and matched by a semi-trusted exchange. Matched orders are settled on the Bitcoin blockchain, where each successful trade between parties appears as a set atomic-colored coins swap transactions. Unfilled and expired orders are discarded. The exchange does not take possession of the traded coins, but needs to be trusted to match trades correctly.

Lykke has launched the exchange initially for the main currencies, cryptocurrencies and Lykke coin (entitlement to the shares of Lykke company). Perspective asset classes include futures and options on digital assets, crowd-funded loans for retail and private equity financing for small and medium-sized enterprises, contracts for difference, zero coupon bonds and other fixed income and natural capital bonds.

Lykke exchange and all its tools and services are open source; the transparency of technology is ideal for research. The paper provides a high-level overview of the exchange and concludes with a research agenda.

Numismatics, the systematic study and collecting of coins and related items such as tokens, medals, and paper money, has been a recognized scholarly discipline since the Middle Ages. Archaeologists, historians, economists, artists, and engravers have found numismatics a valuable adjunct to their respective fields of study. Coins are the official product of an issuing authority, and as such they can provide an important primary historical source of documentation concerning monetary values, patterns of economic exchange, trade routes, colonization, migration, military campaigns, linguistic and epigraphic data, mythology, religion, art, historical portraits, and views of buildings, monuments, and statues that have long since been destroyed. For the researcher in American history, numismatics can provide insights into historical economic trends.

This paper aims to elaborate on the optimization of two particular cryptocurrency portfolios in a mean-variance framework. In general, cryptocurrencies can be classified to as coins and tokens where the first can be thought of as a medium of exchange and the latter accounts for security or utility tokens depending upon its design.

Against this backdrop, this empirical study distinguishes, in particular, between pure coin and token portfolios. Both portfolios are optimized by maximizing the Sharpe ratio and, subsequently, compared with alternative portfolio strategies.

The empirical findings demonstrate that the maximum utility portfolio of coins, with a risk aversion of λ = 10, outweighs alternative frameworks. The portfolios optimized by maximizing the Sharpe ratio for both coins and tokens indicate a rather poor performance. Testing the maximized utility for different levels of risk aversion confirms the findings of this empirical study and confers them more robustness.

Further investigation is strongly recommended as tokens represent a new phenomenon in the cryptocurrency universe, for which only a limited amount of data are available, which restricts the sampling. Furthermore, future study is to include more sophisticated optimization models using different constraints in portfolio creation.

In light of the persistently substantial volatility in cryptocurrency markets, the empirical findings assert that portfolio managers are advised to construct a global minimum variance portfolio. In the absence of sophisticated optimization models, private investors can invest according to the market values of cryptocurrencies. Despite minor differences in the risk and reward ratios of the portfolios tested, tokens tend to be more speculative, especially, if the Tether token is excluded, which may require enhanced supervision and investor protection by regulating authorities.

As the current literature investigates on diversification effects of blended cryptocurrency portfolios rather than making an explicit distinction, this paper reflects one of the first to explore the investability and role of diversifying coins and tokens using a classic Markowitz approach.

Since the democratic transition in 1986, the Philippines has made considerable progress in re-establishing the legal/constitutional basis of civilian supremacy. Legislative control over the military's budget and appointment as well as the use of paramilitary units were re-instituted. Congress also assigned civilian court jurisdiction over human rights cases involving state security forces. An independent human rights commission was given power to investigate allegations of abuses. Constitutional limits were written into the President's ability to mobilize and deploy the military during emergency situations. Notwithstanding, the present structure of the Philippine security forces remains problematic. Of the three services, the army is primarily focused on counterinsurgency (COIN) operations, with the police and paramilitary providing support. The army relies on large formations for its COIN operations and less on Special Forces, which owing to historical interventionist and coup-plotting proclivities, has been numerically emasculated.

Using a case study method, the chapter probes how local civilian authorities in Leon, Iloilo (a town in central Philippines) are able to monitor, supervise or control security sector activities within their area of jurisdiction. A considerable gap exists between each force's understanding of its functions and what they actually do in relation to other state security forces. The army performs mostly non-combat tasks in line with COIN as well as non-traditional tasks. The police are involved mostly in law enforcement and provide augmentation force to army-led COIN operations, but greatly handicapped in detection and investigation matters. The paramilitary is utilized primarily for COIN as territorial defense forces but not for other emergency tasks as envisioned in the law. A tighter relationship exists on the ground between the army unit and the paramilitary, whereas a gap is evident between the army and the police regarding the geographic scope of response to rebel threat. The local government played no significant role in the peace initiative brokered in the 1990s nor has the town peace and order council been the framework of choice in seeking more constructive engagements between the civilian authorities and security forces.

This paper aims to investigate feedback trading and autocorrelation behavior in the cryptocurrency market.

It uses the GJR-GARCH model to investigate feedback trading in the cryptocurrency market.

The findings show a negative relationship between trading volume and autocorrelation in the cryptocurrency market. The GJR-GARCH model shows that only the USD Coin and Binance USD show an asymmetric effect or leverage effect. Interestingly, other cryptocurrencies such as Ethereum, Binance Coin, Ripple, Solana, Cardano and Bitcoin Cash show the opposite behavior of the leverage effect. The findings of the GJR-GARCH model also show positive feedback trading for USD Coin, Binance USD, Ripple, Solana and Bitcoin Cash and negative feedback trading for Ethereum and Cardano only.

This paper contributes to the literature by extending Sentana and Wadhwani (1992) to explore the presence of feedback trading in the cryptocurrency market using a sample of the most active cryptocurrencies other than Bitcoin, namely, Ethereum, USD coin, Binance Coin, Binance USD, Ripple, Cardano, Solana and Bitcoin Cash.