Seasonal Inventory Management Model for Raw Materials in Steel Industry

We developed a seasonal inventory management model for raw materials, such as iron ore and coal, for multiple suppliers and multiple mills. The Nippon Steel Corporation imports more than 100 million tons of raw material annually by vessels from Australia, Brazil, Canada, and other countries. Once these raw materials arrive in Japan, they are transported to domestic mills and stored in yards before being treated in a blast furnace. A critical problem currently facing the industry is the limited capacity of the yards, which leads to high demurrage costs while ships wait for space to open up in the yards before they can unload. To reduce the demurrage costs, the inventory levels of the raw materials must be kept as low as possible. However, inventory levels that are too low may lead to inventory shortage resulting from seasonal supply disruptions (e.g., a cyclone in Australia) that delay the supply of raw materials. Because both excess and depleted inventory levels lead to increased costs, optimal inventory levels must be determined. To solve this problem, we developed an inventory management model that considers variations on the supply side, differences that should be observable upon looking at the ship operations. The concept is to model the probability distribution of ship arrival intervals by brand groups and mills. We divided ship operations into two stages: arrival at all mills (in Japan) and arrival at individual mills. We modeled the former as a nonhomogeneous Poisson process and the latter as a nonhomogeneous Gamma process. Our proposed model enables inventory levels to be reduced by 14% in summer and 6% in winter.

Yeo Woon Taek v. New Nippon Steel Corporation

On October 30, 2018, the South Korean Supreme Court, in an 11–2 decision, upheld the judgment of the lower court, which ordered New Nippon Steel Corporation, a Japanese company, to provide KRW 100 million (approximately USD 84,000) in compensation to each of the four plaintiffs, who were forced to work at Japanese steel mills during World War II. In an earlier 2012 decision, the Supreme Court remanded the case after holding that the claims were not precluded by the Agreement on the Settlement of Problems Concerning Property and Claims and the Economic Cooperation Between the Republic of Korea and Japan (Claims Agreement). The Supreme Court held that the Claims Agreement was not a result of negotiation about compensation for Japanese colonization, but rather was a political agreement the purpose of which was to resolve the financial and civil debt/credit relationship between Korea and Japan. On the final appeal, the Supreme Court concluded that plaintiffs’ claims were directly related to the illegality of Japan's colonial rule over the Korean Peninsula and that the rights of the victims of forced labor to make a compensation claim did not fall within the scope of the Claims Agreement.

The Views of Korean International Law Scholars Regarding the 2012 Supreme Court Decisions on Compensation for Forced Labor

Among the victims of the Japanese occupation of Korea were those who were forced to work for Japanese corporations against their will by the Japanese government. After unsuccessfully seeking recourse in Japanese courts, some forced labor victims filed suit in Korean courts, seeking compensation from the Mitsubishi Heavy Industries Corporation and the New Nippon Steel Corporation. In two groundbreaking decisions, the Supreme Court of Korea ruled in favor of the plaintiffs on May 24, 2012. This note offers non-Korean readers a survey of the views of Korean international law scholars on the issues and implications of the Court’s rulings.

The Latest Trends in Refractories Technology for Iron and Steel Production at Nippon Steel Corporation

In this report, the trends in refractories technologies for iron and steel production at Nippon Steel Corporation in the last few decades are outlined. Amid dramatic changes in crude steel production accompanying increased ratios in higher quality of steel and sophisticated refining methods, in in our refractory ceramics R&D Div., actual machines have been realized by practicing developed outcomes with technologies for every production process relating to: refractory material quality, furnace building or execution, reparation, diagnosis, demolition, and recycling. Thus, continuing reduction in the unit consumption of refractories has been steadily performed. Additionally, technical issues are reduced to further enhance and maintain our international competitiveness in refractories technologies.

Precise Determination of Thermal Expansion Coefficients Observed in 4H-SiC Single Crystals

The coefficient of thermal expansion (CTE) of SiC single crystals is important, in particular, for both designing device assembly and controlling stress distributions in heteroepitaxial thin film structures grown onto SiC substrates. We have performed very precise measurements of the CTEs for SiC single crystals comprising of single 4H polytype PVT-grown in NIPPON Steel Corporation for a temperature range from 123 K to 473 K using a laser interferometry method. This method allows us to directly measure the temperature dependent variation in thermal expansion of the crystal volume with much higher accuracy, and enables us to straightforwardly obtain practical information of CTE data. Furthermore in order to discuss the CTE behavior for a wider temperature range the CTEs at higher temperatures up to 1573 K have been also measured using dilatometer method. The CTE obtained for a nitrogen-doped 4H-SiC single crystal increases continuously from 0.8 ppm/K to 3.1 ppm/K for temperatures of 273 K and 423 K respectively, and further increases to 5.4 ppm/K at 1273 K. We conclude from our data that the CTE variations are likely to be almost independent of the crystal axis directions of SiC from 123 K up to 1573 K.