The concentrated inspection campaign (CIC) is a derivative of the port state control (PSC) supplement, which is a fixed single series of deficiency inspections performed for three consecutive months at the end of each year. This study used grey relational analysis (GRA) and the technique for order preference by similarity to ideal solution (TOPSIS) to analyze the data of 71,376 deficiency records with 496 deficiency codes and 21 ship types in the Paris MoU for the last three years so as to improve the existing focus inspection pattern, which uses only the most accumulated number of deficiency series of the previous year’s PSC inspection. It also combines the three-sigma rule to find the inspection items most likely to be found as deficient by the port state control officer (PFSO) of the member country and creates a new rolling CIC scheme with deficiency inspection data for the last three years, which can filter out the significant deficiency codes with high numbers of deficiency inspections and use them as a modified CIC. It can not only solve the existing CIC’s lack of thoroughness, but also avoid the problems of missing important inspection codes, missing substandard ships, and failing to meet the inspection consensus. The new CIC inspection mechanism created in this paper can indeed identify potential substandard ships more effectively and fill the inspection gap of the existing port state control.

Currently, the field of microgear manufacturing faces various processing challenges, particularly in terms of size reduction; these challenges increase the complexity and costs of manufacturing. In this study, a technique for microgear manufacturing is aimed at reducing subsequent processing steps and enhancing material utilization. This technique involves the use of trough dies with extrusion-cutting processing, which enables workpieces to undergo forming in a negative clearance state, thus reducing subsequent processing time for micro products. We conducted finite element simulations using microgear dies, measuring stress, velocity, and flow during the forming process of four types of dies-flat, internal-trough, external-trough, and double-trough dies. The results indicated that the buffering effect of the troughs reduced the rate of increase in the material’s internal stress. In the cavity, the material experiences a significant increase in hydrostatic pressure, leading to the formation of a “hydrostatic pressure wall”. This pressure barrier imposes substantial constraints on the flow of the material during dynamic processes, making it difficult for the material to move into the remaining areas. This effectively enhances the blockage of material flow, demonstrating the critical role of hydrostatic pressure in controlling material distribution and movement. In addition, combining the characteristics of both into a double-trough die enhances the overall stability of forming velocity, reduces forming load and energy consumption, and maximizes material utilization. Results further revealed that microgears manufactured using double-trough dies exhibited defect-free surfaces, with a dimensional error of less than 5 μm and tolerances ranging from IT5 to IT6. Overall, this study offers new insights into the traditional field of microgear manufacturing, highlighting potential solutions for the challenges encountered in current microstamping processes.

This study investigated the application of a glass die in the forming of microproducts. Lower surface friction and better material flow are achieved in the microforming process when using a glass die than when using a metal die. In contrast to metal dies, glass dies need not repeatedly polished or coated to maintain their smooth surface. Moreover, lubrication is required in the microforming process in the case of a metal die but not glass die. We performed simulated and experimental double-cup extrusion tests on glass dies and found that glass dies affect the direction of material flow. Overall, this study demonstrates that a larger contact area between the billet and the die, a lower friction force, better material flow at specific locations, and a smaller difference between internal and external flows can be achieved when using a glass die in the microforming process than when using a metal die in this process.

This study explores the feasibility of using polyurethane (PU) elastomer as a flexible punch-filling medium in cold forming. Microforming processes encounter challenges such as size effects and friction effects, which can lead to defects including fractures, distortions, and central depressions. The proposed method incorporates a high-hardness PU plate (95A) with excellent elasticity and near-incompressibility to address these issues. By compensating for axial compression through lateral expansion, the PU plate distributes pressure uniformly, reduces central stress, mitigates central acceleration effects, and minimizes defects caused by velocity gradients. Experiments and simulations using aluminum alloy Al 1050-O demonstrate that the PU-assisted extrusion–cutting process improves material flow, redistributes forming pressure, and enhances forming stability compared to conventional methods. This approach shows significant potential for advancing microforming technologies, particularly in industries requiring high-precision components.

The early twenty-first century has witnessed forgeries of antique silver coins (including Japanese coins, Qing Dynasty coins, Yuan-Shikai-era coins, and Republic of China coins). Some forgers wallow in extravagant profits from illegal trading in fake coins with correct weights that combine some silver with cheaper metals. Exceptional forgers can deceive coin collectors by delivering mostly silver pieces of the same weights and sizes as genuine silver coins. Specific gravity is the ratio of masses for equal volumes of different substances; even though numerous forgers understand coin weights and thus deliver fake products with the correct weights, the aforementioned forgery process cannot counterfeit the specific gravity values of silver coins. Hence, the specific gravity values of silver products can be used to distinguish genuine coins from counterfeits. This paper explains a multistep process for distinguishing genuine from counterfeit silver coins. Calculations of specific gravity are combined with a nonlinear constraint method to estimate the ingredients of alleged silver coins. When the ingredients of a coin have been ascertained, whether a coin is genuine or counterfeit can be proven.