• 해양환경안전학회지
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• 제23권3호
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• pp.273-278
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• 2017

This paper is to study a technique to detect the real-time route aberrance on the passage route using bumper area of the ship domain theory. In order to evaluate the risk of route aberrance, a quarter line was created between the center line and the outer line, and a passage route with the image line outside the outer line was designed. It calculated the real-time route aberrance with the vessel bumper area to measure the risk level on the passage route. The route aberrance using overlap bumper area was simulated through three kinds of scenario vessel at the designed passage route. In this paper, we proposed Ratio to Aberrance Risk as one of the evaluation parameter to detect the route aberrance risk at each sector in the passage route and to give the evaluation criteria of 5 levels for seafarer's navigation safety. The purpose of this work is to provide the information of the route aberrance to seafarer automatically, to make it possible to prevent the human errors of seafarer on the high risk aberrance route. As the real-time risk of route aberrance on the passage route is automatically evaluated, it was well thought that seafarer can have only a little workload in order to know the risk of route aberrance at early-time. Following the further development of this work, the techniques for detecting the real-time route aberrance will be able to use the unmanned vessel.

• 해양환경안전학회지
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• 제14권1호
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• pp.71-76
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• 2008

남해안은 우리나라 전체 항만의 입항척수의 58.1%출 차지하며, 위험화물 운반선의 척수를 기준으로 할 경우 68.9%를 차지하여 통항위험에 노출되어 있다. 따가서 남해안 주요항만에 입출항하는 선박의 교통량과 흐름을 조사하여 교통환경스트레스 모델을 적용하여 해역별 위험도를 평가하고, 위험도와 해양사고 및 입출항 척수와의 관계 분석을 통해 주요항만의 문제점과 해결책을 마련할 기초자료를 제시하고자 한다.

• 한국통신학회논문지
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• 제34권5B호
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• pp.449-454
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• 2009

본 논문에서는 먼저 선박환경에서 USN 구축을 위한 하드웨어와 소프트웨어 플랫폼을 분석하였다. 하드웨어 플랫폼에서는 기존의 CC2420기반의 mote 기술을 분석하였고 소프트웨어 플랫폼에서는 TinyOS 플랫폼을 분석하였다. 다음으로 USN 통신방식의 표준인 IEEE 802.15.4의 물리계층을 분석하고 선박USN 성능분석을 위해 Matlab을 사용하여 ZigBee/IEEE 802.15.4 물리계층에 대해 성능평가를 수행하였다. 결과적으로 이동하는 선박환경에서의 선박USN 구축에 관한 타당성을 성능평가를 통해 검증하였다.

• 한국물환경학회지
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• 제35권2호
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• pp.115-122
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• 2019

The objective of this study was to investigate the sonophysical and sonochemical effects induced by acoustic cavitation in heterogeneous systemin a 28 kHz double-bath reactor using calorimetry, the aluminiumfoil erosion test, and the luminol test. With no glass beads, calorimetric power in the inner vessel increased as much as the outer sonoreactor lost and total calorimetric power was maintained for various liquid height conditions (0.5 ~ 7 cm) in the vessel. Higher calorimetric energy was obtained at higher liquid height conditions. Similar results were obtained when glass beads were placed with various beads heights (0.5 ~ 2.0 cm) and relatively high calorimetric energy was obtained in spite of large attenuation in the glass beads layer. An aluminium foil placed between the bottom of the inner vessel and the glass beads layer was damaged, indicating significant sonophysical effects. Much less damage was detected when the foil was placed above the beads layer due to large attenuation of ultrasound. Sonochemical effects, visualized by sonochemiluminescence (SCL), also decreased significantly when the beads were placed in the vessel. It was established that the optimization of the liquid height above the solid-material layer could enhance the sonophysical and sonochemical effects in the double-bath sonoreactors.

• 해양환경안전학회지
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• 제28권2호
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• pp.290-296
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• 2022

전 세계 해상 선박사고 건수는 감소하고 있지만, 국내 해상 사고 건수는 증가하고 있다. 이러한 이유에서 국내 선박의 해양 사고를 줄이기 위한 한 가지 방법으로 사고 건수가 가장 많은 어선과 낚시어선을 대상으로 하는 어선복원성기준에 관한 연구를 수행한다. 국제해사기구(IMO)와 국내 그리고 일본, 중국, 캐나다 해외 3개국의 어선복원성기준을 각각 조사하고, 상호 비교 분석한 결과외국의 기준들 대비 국내 기준이 가장 완화된 기준임을 알 수 있었다. 비교 분석 결과를 토대로 국내 어선복원성 기준을 보완하기 위한 어선복원성기준 개정(안)을 5가지 평가항목에 대해서 제안했다.

• 한국초전도ㆍ저온공학회논문지
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• 제15권4호
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• pp.53-58
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• 2013

KSTAR in-vessel cryo-pump has been installed in the vacuum vessel top and bottom side with up-down symmetry for the better plasma density control in the D-shape H-mode. The cryogenic helium lines of the in-vessel cryo-pump are located at the vertical positions from the vacuum vessel torus center 2,000 mm. The inductive electrical potential has been optimized to reduce risk of electrical breakdown during plasma disruption. In-vessel cryo-pump consists of three parts of coaxial circular shape components; cryo-panel, thermal shield and particle shield. The cryo-panel is cooled down to below 4.5 K. The cryo-panel and thermal shields were made by Inconel 625 tube for higher mechanical strength. The thermal shields and their cooling tubes were annealed in air environment to improve the thermal radiation emissivity on the surface. Surface of cryo-panel was electro-polished to minimize the thermal radiation heat load. The in-vessel cryo-pump was pre-assembled on a test bed in 180 degree segment base. The leak test was carried out after the thermal shock between room temperature to $LN_2$ one before installing them into vacuum vessel. Two segments were welded together in the vacuum vessel and final leak test was performed after the thermal shock. Commissioning of the in-vessel cryo-pump was carried out using a temporary liquid helium supply system.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.899-908
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• 2021

It is expected that the global market for vessel repair and remodeling will grow up to the scale of about 25 billion dollars by 2023. Korea's shipbuilding industry is leading the world with its international competitiveness in design and production technology. The actual status of vessel repair industry, however, is poor as there are only two or three companies for vessel repair that can deal with large vessels in the area of Gyeongnam. The reason is that civil complaints are filed severely about environmental problems and environment-related regulations are so strict that it is fairly hard to get governmental approval for the operation of a vessel repair workplace. Domestic vessel repair companies mainly target small- and medium-sized vessels. There are only few workplaces that can carry out regular examination or repair work on large vessels such as LNG vessels, and due to the high price of vessel repair, most of the domestic repair work on large vessels including LNG vessels tends to be snatched by markets in Southeast Asia or China. Despite the tremendous domestic demand of Korea that has established the world's first shipbuilding industry and world's sixth biggest harbor infrastructure, its vessel repair industry can be said to be in very poor condition. In order to vitalize vessel repair industry, this study is aimed to analyze the environmental influence of vessel repair workplaces in Gyeongnam where vessel repair companies are concentrated and suggest standard processes by analyzing vessel repair processes precisely.

• 해양환경안전학회지
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• 제19권2호
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• pp.219-224
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• 2013

해양유류오염사고가 발생한 경우에 필요한 모든 방제자원을 사전에 확보하고 사고에 대응하는 것이 가장 효과적이지만 현실적으로는 한계가 있는 실정이다. 그러므로 대규모 유류오염사고에 대비하여 유류오염으로 피해를 입게 되는 오염지역의 어선을 활용하는 방안이 중요한 대안이 될 수 있다. 미국 등 선진국에서도 지역 어선을 이용한 임시방제정 프로그램이 개발되어 운영되고 있는 사례를 찾아볼 수 있다. 본 연구는 국내 소형어선에 적합한 기름방제용 스위핑 암 시스템을 검토하였다. 모델로 선정된 소형 선박은 연안유자망어선 및 연안복합어선으로 2.5~3.5톤, 길이 8~9 m, 폭 2.5~2.8 m, 마력 200~250 HP, 선질 FRP인 어선이다. 개발된 장치는 모델 선박에 간편하게 장착할 수 있고 이동이 가능한 구조로 설계되었다. 조립 및 분해를 쉽게 하기위해 각 부품의 무게를 10 kg 이하로 구성함으로써 현장 실용성을 높였다.

• 한국통신학회논문지
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• 제35권6B호
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• pp.859-866
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• 2010

예기치 못한 상황에 의한 선박 내 화재나 선체 파손 등 긴급 상황 발생 시에 대형의 해난 사고가 발생할 수 있다. 특히, 해수와 직접적으로 접촉하는 선체는 파도와 조류 등에 의해 다양한 저항과 흔들림 운동의 영향을 받게 되는 데 이를 고려한 선박 USN 미들웨어와 선박 내 상황 인식을 기반으로 한 시스템이 필요할 것이다. 이에 본 논문에서는 해양 디지털 선박의 무선 센서를 이용하여 수집된 위험 상황 정보를 분석하는 시스템을 제안하였으며, 센싱된 데이터를 분석하기 위하여 역전파 신경망을 설계하였다. 위험 상황별로 각 300개의 데이터 집합을 사용하여 역전파 신경망을 실험한 결과 화재 위험 상황에 대해서는 96%의 정확도를 가졌고 선체 위험 상황에 대해서는 약 88.7%의 정확도를 나타냈다. 제안된 시스템은 시스템의 정확도를 개선하기 위하여 전방향 에러 정정 시스템(LDPC)을 구현하였고 진단된 결과는 CDMA 방식으로 전송하여 해양 디지털선박 상황 모니터링 시스템을 구현했다.

• 한국항해항만학회지
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• 제31권2호
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• pp.127-132
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• 2007

The primary purpose of this study is to examine empirically the effect of the organizational characteristics in the vessel with foreign crews on their self-efficacy and organization commitment. Currently, the restrictions on the employment of the foreign crews are being eased in the Korean shipping industry and many problems are occurring consequently. However, specific and empirical studies on the relevancy of organizational characteristics to the crew's self-efficacy and organizational commitment on board the vessels with combined crews have not yet been carried out. To solve these problems, we examined how the organizational characteristics such as communication and leadership trust of different language and culture related to vessels with combined crews influence on the self-efficacy, job satisfaction and organizational commitment of the foreign crews through SEM analysis. According to the results, hypothesis 1, 2 and 3 were all supported with statistical significance. That means that communication and leadership trust of the vessel with foreign crew had positive effects on their self-efficacy and that such self-efficacy also had a positive effect on the organizational commitment and job satisfaction. To conclude, this study suggests that foreign crew's self-efficacy should be firstly enhanced in order to improve organizational commitment on the vessel with combined crews. Furthermore, studies on self-efficacy of foreign crew's organization are urgently needed to enhance the effectiveness of an organization in a vessel with combined crews that has special environment - working environment with depression and uneasiness due to the exposure to the different language and culture, and excessive stress from the social and psychological adaptation. Therefore, an attempt of this study is considered to be timely since there has not been a study on this subject so far and result of this study will contribute a lot to the organization management of a vessel with combined crews.