• 전자공학회논문지SC
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• 제44권3호
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• pp.70-76
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• 2007

해미래는 한국해양연구원 해양시스템안전연구소에서 해양수산부의 지원으로 2001년부터 6년에 걸쳐 순수 국내 기술로 개발한 6, 000m급 과학탐사용 섬해 무인잠수정이다. 해미래는 2006년 4월에 동해 1차 시도에서 1, 065m까지, 10월 동해 2차 시도에서 2, 026m 해저변까지, 11월에 필리핀 앞 태평양에서 5, 775m 해저변까지 시험 탐사를 성공적으로 수행하였다. 이로서 우리나라는 세계에서 4번째로 독자적인 섬해 무인 잠수정 설계 및 개발 기술을 확보하였으며, 앞으로 국가 전략 기술로서의 섬해 연구를 위한 기초를 마련하였다. 본 논문에서는 섬해 무인잠수정의 구성과 기능에 대하여 설명하고 해미래의 개발 및 시험 과정에 대하여 간단히 설명한다. 또한 첫 탐사를 위한 준비 과정과 3차례에 결친 시험 탐사 결과를 요약한다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권2호
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• pp.782-795
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• 2019

Safety is always acritical focus of exploration of ocean resources, and it is well recognized that human factor is one of the major causes of accidents and breakdowns. Our research developed a dynamic human reliability assessment approach, Predicted Mean Vote-Cognitive Reliability and Error Analysis Method (PMV-CREAM), that is applicable to monitoring the cognitive reliability of oceanauts during deep-sea missions. Taking into account the difficult and variable operating environment of manned submersibles, this paper analyzed the cognitive actions of oceanauts during the various procedures required by deep-sea missions, and calculated the PMV index using human factors and dynamic environmental data. The Cognitive Failure Probabilities (CFP) were calculated using the extended CREAM approach. Finally, the CFP were corrected using the PMV index. This PMV-CREAM hybrid model can be utilized to avoid human error in deep-sea research, thereby preventing injury and loss of life during undersea work. This paper verified the method with "Jiaolong" manned submersible 7,000 m dive test. The"Jiaolong" oceanauts CR(Corrected CFP) is dynamic from 3.0615E-3 to 4.2948E-3, the CR caused by the environment is 1.2333E-3. The result shown the PMV-CREAM method could describe the dynamic human reliability of manned submersible caused by thermal environment.

• Geomechanics and Engineering
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• 제14권5호
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• pp.467-477
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• 2018

Estimation of hydraulic parameters is a critical step during design of foundation dewatering works. When many piles are installed in an aquifer, estimation of the hydraulic conductivity should consider the blocking of groundwater seepage by the piles. Based on field observations during a dewatering project in Shanghai, hydraulic conductivities are back-calculated using a numerical model considering the actual position of each pile. However, it is difficult to apply the aforementioned model directly in field due to requirement to input each pile geometry into the model. To develop a simple numerical model and find the optimal hydraulic conductivity, three scenarios are examined, in which the soil mass containing the piles is considered to be a uniform porous media. In these three scenarios, different sub-regions with different hydraulic conductivities, based on either automatic inverted calculation, or on effective medium theory (EMT), are established. The results indicate that the error, in the case which determines the hydraulic conductivity based on EMT, is less than that determined in the automatic inversion case. With the application of EMT, only the hydraulic conductivity of the soil outside the pit should be inverted. The soil inside the pit with its piles is divided into sub-regions with different hydraulic conductivities, and the hydraulic conductivity is calculated according to the volume ratio of the piles. Thus, the use of EMT in numerical modelling makes it easier to consider the effect of piles installed in an aquifer.

• 한국해양공학회지
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• 제32권4호
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• pp.287-295
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• 2018

This paper presents the results of an exploration of the ferromanganese crusts of Western Pacific Seamount registered by the Korean government. This area has been surveyed with a deep-sea camera and crust samples have been acquired by deep-sea dredging since 2013. On October 18-19, 2017, a united research team from KIOST and KRISO explored two blocks, OSM11 and OSM07, on the seamount using Hemire ROV. A precise survey was conducted on the ferromanganese crusts and sediments covering the slope/top of OSM11 and the middle flat area of OSM07. Rock samples were collected with precise positioning, and HD videos were recorded for 7 hours. This paper discusses the technical issues of this exploration in terms of (1) how to deal with an emergency situation during an electric power blackout, (2) the improvement of the thruster power by adding cooling plugs to the housings of the thruster amplifiers, (3) the relative motion of the depressor by changing the fixing method of the cable terminator, which affects the service life of the cable, (4) a sampling technique for the steep slope of the seamount, (5) integrated navigation under a USBL blackout, and (6) a 3-dimensional image mosaic for visualizing the distribution state of the crusts.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권6호
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• pp.1044-1055
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• 2015

DPCap analysis can assist in determining the maximum environmental forces the DP system can counteract for a given heading. DPCap analysis results are highly affected by the thrust forces provided by the thrust system which consists of several kinds of thrusters. The thrust forces and moment are determined by the maximum thrust of the thrusters as well as the thruster configuration. In this paper, a novel local optimization of thruster configuration based on a synthesized positioning capability criterion is proposed. The combination of the discrete locations of the thrusters forms the thruster configuration and is the input, and the synthesized positioning capability is the output. The quantified synthesized positioning capability of the corresponding thruster configuration can be generated as the output. The optimal thruster configuration is the one which makes the vessel has the best positioning capability. A software program was developed based on the present study. A local optimization of thruster configuration for a supply vessel was performed to demonstrate the effectiveness and efficiency of the program. Even though the program cannot find the global optimal thruster configuration, its high efficiency makes it essentially practical in an engineering point. It may be used as a marine research tool and give guidance to the designer of the thrust system.

• Ocean and Polar Research
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• 제36권4호
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• pp.367-371
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• 2014

In early 1990s, the Korean government has launched a deep-sea research program to secure the stable long-term supply of strategic metallic minerals including Cr, Cu and Ni. Through the pioneering surveys, Korea registered $150,000km^2$ of Mn-nodule field in the Clarion-Clipperton area, the NE equatorial Pacific to the international sea-bed authority (ISA) in 1994. Following the ISA exploration code, the final exclusive exploration area of $75,000km^2$ was assigned in 2002, based on results of eight-year researches of chemico-physical properties of nodules, bottom profiles and sediment properties. Since that time, environmental studies, mining technical developments including robot miner and lifting system and establishment of smelting systems were accompanied with the detailed geophysical studies to decipher the priori mining area until 2009. Major points of the recent Korea Mn-nodule program are deployed on a commercial scale until 2015. In order to meet the goals, we developed a 1/5 scaled robot miner compared to commercial one in 2012 and performed a mining test at the water depth of 1,370 m in 2013. In addition, detailed 25,000 scaled mining maps in the priori area, which can provide operation roots of the miner, will be prepared and an environmental-friendly mining strategy will be pursued based on the environmental impact test and environmental monitoring.

• Ocean and Polar Research
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• 제27권1호
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• pp.97-108
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• 2005

The International Seabed Authority (ISA) formally came into existence upon the entry into force of the UNCLOS on 16 November 1994. By adopting the Implementing Agreement in 1994, UNCLOS has the universality as a Magna Carta of International Ocean Regime, and the Deep Seabed Mining Regime could be operated as a unique one for the benefit of mankind. During last 10 years, ISA established the institutional framework successfully and made substantial and tangible progress in formulating the rules, regulations and procedures for the prospecting and exploration for polymetally nodules. Furthermore, RPI's obligations had been carried out completely, and the 7 RPI made contract with ISA to become a contractor who has an at least 15 you exclusive right for exploration in their allocated site. However, due to the uncertainty of commercial mining, the number of representatives from developing countries has been getting looser and looser and ISA has a problem of quorum of the Assembly. Land-based producers took a very strong opposite position to the contractors to make their loss in the minimum level. For the next decade, it might be prospected that ISA will focus on monitoring the contractor's activities, making rules, regulations and procedures for exploration on cobalt rich crust, sulphide and methane hydrate and implementing environment studies.

• 지구물리와물리탐사
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• 제27권1호
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• pp.37-50
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• 2024

MT 탐사는 측점 주변의 지형과 바다와 같은 외부적 환경 요인에 의해서도 자료에 영향을 받는데, 특히 섬에서 수행된 MT 탐사 자료에는 지형효과와 해양효과가 복합적으로 작용하게 되며, 올바른 해석을 위해서는 두 효과에 대한 이해가 필요하다. 본 연구에서는 지형과 해양의 영향이 포함된 MT 반응(겉보기비저항, 위상)을 분석하기 위해 깊은 바다에 둘러싸인 원뿔 형태의 소규모 섬 모델을 생성하였다. 지형만을 고려한 지형모델, 지형과 바다를 동시에 고려한 섬 모델에 대하여 2차원 순산모델링과 3차원 순산모델링을 수행하고 MT 반응을 확인하였다. 3차원 섬 모델에 대해 2차원 모델링을 수행하면, 측선의 직교 방향에 대한 지형 변화와 바다를 고려하지 못하는데, 3차원 모델링을 수행함으로써 모든 방향의 지형 변화와 섬을 둘러싼 바다를 고려한 MT 반응을 얻을 수 있었다. 언덕과 같이 주변의 기복이 심한 지형에서는 겉보기비저항 XY 성분과 YX 성분의 벌어짐 현상이 전형적으로 발생하였다. 저비저항 이상체가 해수면 아래 1 km 심도에 존재할 경우, MT 반응에서 지형과 바다로 인한 변동과 구분할 수 있으며, 심도 증가에 따라 이상체의 영향이 감쇠하였다. 다양한 조건에서 모델링을 수행하고 MT 반응을 분석함으로써, 현장 MT 자료에 대한 이해를 높이고 자료 해석에 도움이 될 수 있을 것으로 기대한다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2010년도 학술대회 초록집
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• pp.47-50
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• 2010

• 지구물리와물리탐사
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• 제11권4호
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• pp.286-301
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• 2008

해양과 인접한 지역에서 MT탐사 자료를 해석하는 경우, 해양은 심부 구조의 반응을 왜곡시키는 역할을 한다. 본 연구에서는 해저면 MT탐사에서 해저 지형의 영향을 제거하는 지형보정 기법을 바탕으로, 반복적으로 해양효과를 보정하는 기법을 개발하였다. 제안된 기법은 우선 관측 MT 반응에서 주변 해양의 영향을 보정하고, 그 후 해양이 없는 모델공간에서 역산을 수행한다. 주변 해양과 지하구조와의 상호결합 때문에 이 과정은 반복적으로 수행되며, 보정 결과의 변화가 미미할 때 반복과정이 종료된다. 제안된 기법의 검증을 위해 해양을 포함하는 3차원 순산 모델링을 통하여 합성 자료를 생성하였고, 1차원 및 2차원 구조에서 보정기법을 적용하였다. 대체적으로 제안된 해양효과 보정 기법은 $2{\sim}3$회의 반복단계를 거친 후 해양이 없는 경우의 지하구조를 성공적으로 복원하였다. 실제 MT 자료와 유사한 자료를 획득하기 위해 1차원 구조로 잘 알려져 있는 제주도에 대한 3차원 모델링을 수행하여 유사 현장 자료를 생성하였다. 제주도 모델의 경우, 해양효과는 약 1 Hz 이하에서 나타나기 시작하였으며 측선의 위치 때문에 해안선과 수직한 전기장 성분에서 상대 적으로 왜곡이 심하게 나타났다. 이러한 왜곡은 3회의 해양효과 보정과정을 통해 성공적으로 제거되었으며, 1차원 및 2 차원 역산은 모델링 시 가정한 제주도의 지하구조를 성공적으로 복원하였다.