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Analysis of pier contact accident in busan new port of south Korea by System-Theoretic Accident Model and Processes (STAMP)

Kim S. R., Wamugi W. J., Camliyurt G., Kim D. W., Park Y. S.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 2

299--304

EN

Marine accidents are caused by complex and diverse causes. Therefore, it is necessary to analyse accidents from the perspective of the whole system rather than the existing analysis models that focus on cause-effect. The STAMP analysis is a constraint-based model that focuses on improper management or enforcement of safety-related constraints in system operation. Thus, as a case study of the application of the STAMP technique in marine accident analysis, the Milano Bridge pier contact accident that occurred on April 6, 2020 in Busan New Port of South Korea was analysed by the STAMP technique in this study. Through this study, it was proposed to break away from the domestic accident investigation, which focused only on the punishment of the ship operator, and to suggest improvements that enable organizations related to the marine accidents to take initiative to take efforts for safety.

2

Solvent Extraction of Co, Ni and Mn from NCM Sulfate Leaching Solution of Li(NCM)O2 Secondary Battery Scraps

Hong H. S., Kim D. W., Choi H. L., Ryu S.-S.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2B

1011--1014

EN

As a part of the study on recycling Li(NCM)O2 lithium-ion battery scraps, solvent extraction experiments were performed using different extraction agents such as PC88A, Cyanex272 and D2EHPA to separate Co, Ni and Mn from the leaching solution. When the ratio of Mn to Ni was about 0.4 in the leaching solution, the separation factor for Co and Mn was found to be less than 10 so that the separation of Co and Ni was insufficient. When solvent extraction was done using the solution with the lower Mn/Ni ratio of 0.05 where Mn was removed by potassium permanganate and chlorine dioxide, more than 99% of Mn could be extracted through five courses of extraction using 30vol% D2EHPA while the extraction rates of Co and Ni were around 17% and 11%, respectively. In the case that Mn was removed from the solution, the extraction rate of Co was higher than 99% whereas less than 7% Ni was extracted using Cyanex272 suggesting that Co and Ni elements were effectively separated.

3

Noise reduction for digital holograms in a discrete cosine transform (DCT) domain

Choi H. J., Seo Y. H., Kim D. W.

Optica Applicata

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2010

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Vol. 40, nr 4

991--1005

EN

This paper presents a method for reducing noise in a digital hologram, which occurs during acquisition. The algorithm proposed initially transforms a digital hologram into frequency-domain data through a discrete cosine transform (DCT), and separates the object from the background in the transformed image. As a noise reduction method, a histogram modification method is applied to the object, while the background is substituted with zero values. Experimental results showed that the proposed scheme improves the visual image quality very much when reconstructed by both the optical system and the PC simulation.