• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.263-265
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• 2012

잠수함이 가장 취약한 시기는 잠수함이 스노클이나 잠망경 운용을 위하여 잠망경 심도로 항해할 경우이며, 이때에는 비음향 탐지센서인 레이더와 광학, 사람에 의한 시각에 탐지될 확률이 매우 높다. 따라서 본 논문에서는 이러한 상황에서 탐지되는 취약성을 극복하고자 잠수함 마스트 및 잠망경 부분에 비음향 스텔스를 적용하고자 한다. 먼저 비음향 탐지센서에 대해서 조사하고, 그에 따른 스텔스 기법을 분야별 분석하여 최적화한 결과 다층형 구조로 선체표면부터 RAM layer, IR layer, Camouflage layer 구조로 각각 RAM layer는 자성재료인 페라이트계열로 3~5mm, IR layer는 Ceramic 또는 Nickel 계열로 1~2mm, Camouflage layer는 군청색 계열 페인팅을 제시하였다.

• Defense and Technology
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• no.10 s.128
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• pp.34-41
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• 1989

프랑스가 제안하는 효율적인 기술이전계획은 점진적인 과정이다. 시작단계에서는 프랑스에서 제공하는 잠수함의 정비유지에만 제한 적용되며, 정비 엔지니어와 기술자들이 계획된 방법으로 잠수함의 개념과 기술에 관한 지식을 획득할수 있을 것이다. 목표는 현지 조선소가 잠수함의 창정비(overhaul)를 능숙히 수행할 수 있도록 하는 것이다. 또한 기술이전은 자국내 잠수함 건조의 경우 3단계에 걸쳐 수행된다(p.39 참조)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.6
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• pp.1330-1334
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• 2012

The submarines reach their weakest point when they sail on the surface to operate snorkel and periscope. At this period, however, there lies a high possibility that the submarines are detected by non-acoustic sensors such as radars, IR signatures, and human observations. In this paper, the non-acoustic stealth was adopted on the mast and periscope of submarines so as to overcome their vulnerability of being easily detected in this given situation. First of all, the non-acoustic detection sensors were investigated and the stealth methods were analyzed. And multi-layered structures consisting of RAM layer, IR layer, and Camouflage layer were proposed on the surface of the submarine. As a results, multi-layered structure was suggested with 3~5 mm of a magnetic material such as ferrite for RAM layer, 1~2 mm of ceramic or nickel for IR layer, and sea-blue paint for Camouflage layer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.716-718
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• 2011

첨단 과학기술의 발달에 따라 미래 해전의 양상은 비대칭적인 전략과 수단이 보편화되는 양상으로 전개될 것으로 전망되며, 비대칭전력의 핵심인 잠수함의 중요성이 대두 될 것으로 판단된다. 따라서 본 논문에서는 중요성이 대두되는 잠수함 측면에서 잠수함을 탐지하는 대잠전 탐지체계를 분석한 결과 소나체계인 음향탐지체계와 전자파, 자기, 광학장비 등으로 탐지하는 비음향탐지체계로 구분되며 각각의 탐지체계로부터 탐지를 거부하고 생존력을 증대시키기 위해 필요한 잠수함의 스텔스 발전 방향을 제시하였다.

• Journal of Preventive Medicine and Public Health
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• v.31 no.1 s.60
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• pp.139-156
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• 1998

Diving related disease including decompression sickness is an important occupational health problem and diving fishermen remain a fairly hazardous occupation in Korea. To prevent diving related disease, we investigate diving patterns, incidence of diving related diseases, and contributing factors of 433 diving fishermen of three coast interviewing and mailing questionnaire in 1996. Mean age of divers was 39.7 years, ranged from 24 to 58 years, 92.8% of these were male, and 58.4% of divers were high school graduates. Mean duration of work as a diver was 12.9 years, ranged from 2 to 40 years. It was found that 70.4% of divers were using hookah system, 22.2% of helmet, and only 2.5% SCUBA. About half of them have learned diving skills from other divers. The peak season of diving was from April to June and mean working days were 20.3 days per month during the peak season. On the average, the divers dived 5-6 times, ranged from 1 to 10 times a day with 51.1 minutes of diving time, ranged from 20 to 120 minutes, at 30 m or 40 m in depth, and 35.5 minute of interval on surface. Most divers ascended slowly making decompression stop, yet the decompression profile used was not based on any scientific knowledge except for their own experiences. It appeared that each diving system had slightly different diving patterns. There were 282(65.0%) divers that suffered from DCS in 1995 and 31.2% of divers were given recompression therapy at a medical facility since they worked as diving fishermen. Skin and musculoskeletal complaints were common symptoms of DCS and 39% of divers experienced a voiding difficulty. In univariate analysis, females have an increased frequency of DCS(93% vs 66% for males). Old age, long duration of work, helmet diving, diving time, diving depth, repetitive diving, and blow up were all contributing factors to DCS. It was found that most diving patterns exceed no decompression limit and did not use the standard decompression table. This suggests that most of divers are at high risk of developing diving related disease with prolonged dives and lengthy repetitive diving in deep depth. Considering the diving patterns and economic aspect of professional diving, the incidence of DCS among diving fishermen in Korea will not decrease in the near future. These findings suggest that periodical health surveillance for divers, and education of health and safety are important for reducing the risk of diving related disease in the population of diving fishermen.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.9
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• pp.837-845
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• 2013

An airlift pump can be used to pump liquids and sediments within itself, which cannot easily be pumped up by a conventional method, by using the airlift effect. This characteristic of the airlift pump can be exploited in a DCFC (Direct Carbon Fuel Cell) so that molten fuel with high temperature may be carried or transported. The basic characteristics of airlift are investigated. A simple system is constructed, where the reservoir is filled with water, a tube is inserted, and air is supplied from the bottom of the tube. Then, water is lifted and its flow rate is measured. Bubble patterns in the tube are observed in a range of air flow rates with the parameters of the tube diameter and submergence ratio, leading to four distinct regimes. The pumping performance is predicted, and the correlation between the supplied gas flow rate and the induced flow rate of water is found.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.131-136
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• 1998

2개의 simulated된 잠수 실험 즉, 심도 19 ATA와 24 ATA의 고압 Heliox 환경하에서, 4명의 다이 버를 대상으로 하여연 188일간 매일 23:00부터 익일7:00시 사이에 각 다이버에대해서 표준적인 polysomnography를 기록했다. 2개의 잠수조건 하에서 양 실험 모두 해저에서 체재하는 동안 의 밤과 감압하는 동안의 밤 동안에는 총수면시간 (Total Sleep Time)의 단축, 수면효율(Sleep Efficiency)의 감소, 입면잠시(Sleep Latency)의 연장, 중도각성회수 (Number of Awakeningss) 와 감소를 보였지만, 어느쪽도 뚜려한 변화가 있었다라고는 할 수 없었다. 24 ATA 잠수조건에서 의 해저에서 체재하는 동안의 밤과 감압하는 동안의 밤 동안에서는 19 ATA 잠수조건에 비해서 4 단계수면(stage 4 sleep )만 유의한 감소를 보였다. 2개의잠수조건 모두 잠수기간 중에 있어서 는 각성하기 쉬운 상황이었으며, 기본적인 수면패턴에 있어서는 큰 변화는 보이지 않았다.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1203-1211
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• 2009

The dynamics of underwater vehicles can be greatly influenced by the dynamics of the vehicle thrusters. The control of the state of the hovering or very slow motion of the underwater vehicle is most important for automatic docking or control of the manipulator of the vehicle. The dynamics of the thruster based on the electric motor is nonlinear and has uncertain parameters. Since the dynamics of the vehicle coupled with the dynamics of the thruster is nonlinear and has uncertain parameters, a robust control is very effective for a desired motion tracking of the uncertain and nonlinear vehicle. In this paper a study was performed on the robust control scheme of the very slow motion or hovering motion of the underwater vehicle actuated by the electric motor. Also, a concurrent control on the state of the vehicle with nonlinearity and uncertain parameters was performed. A sliding mode control algorithm out of robust controllers was designed and applied, which compensates the nonlinear forces and uncertain parameters of the vehicle and actuator. Through a computer simulation, the proposed control scheme was compared with a linear PD controller and its superior performance was validated.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1946-1947
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• 2011

본 논문은 파라미터의 불확실성을 포함한 비선형 무인 잠수정(autonomous underwater vehicles: AUVs)의 속도 제어를 위한 강인 퍼지 제어기를 제안한다. 효율적이고 안정적인 접근을 위해 불확실성을 포함한 비선형 무인 잠수정의 속도 시스템은 타카기-수게노(Takagi-Sugeno: T-S) 퍼지 모델로 표현된다. 리아푸노프(Lyapunov) 안정도 이론을 이용하여, 무인 잠수정의 제어 성능을 보장하는 선형 행렬 부등식(linear matrix inequality: LMI) 형태의 제어기 설계 조건을 유도한다. 제안된 강인 속도 제어기 성능의 유효성을 검증하기 위해 모의실험을 수행한다.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.3
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• pp.107-116
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• 2001

Any small leakages in the submarines could lead to the serious consecutive damages since it operates under high water pressure. Such leakages including damages of pipe and hull itself eventually could incur humane casualties and loss of expensive properties as well as the loss of combat capabilities. In this paper, knowledge based decision system is developed. The domain knowledge is acquired from document of submarine design, design expertise and interview with operator. Damages of hull itself and pipes are treated and decision is recommended whether to stay in the sea or to be blowing, for instance.