• Analytical Science and Technology
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• v.10 no.4
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• pp.300-306
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• 1997

The effective resolution of the direct current potential drop (DCPD) method for crack length determination is strongly affected by a number of factors including wire locations and calibration method. In the present study, the effects of wire locations, thermal EMF and reference probe locations on the accuracy of calibration methods, including Hicks-Pickard equation and Johnson's equation, were examined with the CT specimens which were nine times larger than the standard specimen. In light of experimental results, it was found that Hicks-Pickard equation can accurately represent the a/W-V/Vo relationship when current input wire is located at the load line. It was also found that the accuracy of DCPD method can be greatly improved with the thermal EMF calibration and the use of Vo value at a/W = 0.241. The use of reference potential was found to be impractical when current input wire is located at the load line.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.359-364
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• 2017

This study examined business acts related to leisure boats, so as to investigate the differences of regulations and things to be supplemented, as well as to suggest improvement measures. In order to achieve this purpose, the authors analyzed the respective legislations. The Acts on businesses using leisure boats(or power-driven water leisure crafts) are the Marine Transportation Act, Excursion Ship and Ferry Business Act, Water-Related Leisure Activities Safety Act, and Act on the Development, Management, etc. of Marinas. These Acts have differences in regulations, in terms of gross tonnage, the age of vessels, crewman, and the liquor traffic. These differences can cause problems such as adjusting the gross tonnage of the vessel by modifying the structures of the facilities, assigning old vessels, sailing without crewmen required for safety, and going against fairness in the liquor traffic in similar businesses. Such differences appeared to be caused by the lack of understanding of leisure boats and the series of new legislation which have been added one by one. It is required to raise the understanding on the characteristics of leisure boats and reflect them in the legislation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.928-936
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• 2022

According to the current status of marine accidents in Korea, the number of accidents is steadily increasing by an approximate average of 8.5% per year, and marine accidents are steadily increasing for ships and structures such as floating barges, tugboats, ferries and floating platforms except for fishing ships. In this study, domestic floating structures were classified according to the type of floating structure, and the regulation system and the scope of the application of floating marine structures were schematically illustrated according to related domestic laws such as the Ship Safety Act, Ship Act and Fishing Management and Promotion Act. In addition, considering the state of the marine environment, it was intended to discover structurally delicate parts and risk factors early in blinded safety spots in applying domestic regulations, and to derive effective improvement measures for the discovered risk factors.