• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.53-59
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• 2018

Water pollution is drastically increasing day by day, because of the enhancement in use of livestock, urban sewage detergents and fertilizers. Moreover increase in concentration of phosphorous and nitrogen contained in sewage, leads to green tide problem in the rivers and causes marine pollution. For this problem to solve, several technologies are being researched and developed. Among them, this experiment is a study on Bench-scale STP based on internationally certified sewage treatment equipment by MEPC. 227(64) of IMO. The purpose of this study is to compare the biological treatment efficiency of phosphorus of Bench-scale STP. The ratio of C : N : P was set to 10 : 5 : 3 and 10 : 3 : 1 as the operating conditions. And the operation cycle was set to anoxic(mixed) 70 min - aeration 50 min (70-50), anoxic(mixed) 90 min - aeration 60 min (90-60). As a result, the phosphorous treatment efficiency was 88% at average, and the treatment efficiency was steady at 90-60 better than 70-50. The efficiency of the bench-scale STP has been verified through this experiment and additional experiments are required to derive the optimal operating conditions.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.207-215
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• 2023

The ship system is complex and advanced, and the operation relationship between each element is very high. So it is necessary to approach it in terms of an overall and integrated system in addition to the traditional sequential approach of finding and removing the direct cause of the accident when analyzing the accident. In this study, it is analyzed the recent fire accidents on ships occurred the Korean terrestrial water using a STAMP methodology that is different from conventional accident analysis techniques. This analysis reviews a range of factors, including safety requirements to prevent fires in ships, inappropriate decisions and actions, situations, equipment defects, and recommendations derived from accident analysis results. Through a comprehensive approach to accident prevention using STAMP, alternative evaluations are presented at the component level within the entire system of ships, and they are systematically used for accident prevention and risk evaluation as well as simple accident analysis.