• 제목/요약/키워드: Sea State

검색결과 826건 처리시간 0.027초

On the possibility of freak wave forecasting

  • Janssen, Peter A.E.M.;Mori, Nobuhito;Onorato, Miguel
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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    • pp.121-126
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    • 2006
  • Modern Ocean wave forecasting systems predict the mean sea state, as characterized by the wave spectrum, in a box of size ${\Delta}x{\Delta}y$ surrounding a grid point at location x. It is shown that this approach also allows the determination of deviations from the mean sea state, i.e. the probability distribution function of the surface elevation. Hence, ocean wave forecasting may provide valuable information on extreme sea states.

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독일의 해상유류오염 예방 및 방제체계 고찰 (Study on the Prevention and Combat System of Oil Pollution in Germany)

  • 신옥주
    • 환경정책연구
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    • 제8권1호
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    • pp.97-127
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    • 2009
  • 독일에 있어서 북해와 동해는 여러 측면에서 매우 중요한 의미를 가지고 있다. 북해의 연안국에게 북해변의 경제적 의미가 매우 크다. 이곳에는 수많은 항만들 외에 많은 공업시설이 있으며, 이곳은 또한 농업 발달지역이기도 하다. 바닷물과 강물이 섞인 곳(Brackwassermeer)인 동해의 특징은 북해와는 협수로 연결이 되어서 북해와의 물의 순환이 원활하지 못한 지정학적 위치 때문에 북해처럼 빠른 속도로 유해물질이 처리될 수 없다는 점이다. 크고 작은 선박사고 및 각종 오염 원으로부터 보호하기 위해 동해는 특히 HELKOM협약을 통하여, 그리고 북해는 OSPAR협약을 통하여 노력을 기울이고 있다. 또한 선박사고 시 예인선에 관하여 NethGer-Plan과 DenGer-Plan을 통하여 네덜란드와 독일, 덴마크와 독일간에 협조가 이루어지고 있다. 1995년에 브레멘 부근에서 발생한 팔라스(Pallas)호 사건 이후 독일에서는 미래의 해양안전을 위해서 사용가능한 자원에 대한 연안 각 주간의 협조가 개선되어야 할 필요성이 증대되었다. 그 결과 2003년 1월 1일에 연방과 연안 주정부들은 공동으로 하바리 코만도(Havarie-Kommanando 선박사고 대책부대)를 조직하였다. 하바리 코만도는 중대한 선박 사고 발생 시 대국민작업 및 선박 사고 관련 조직의 동원을 통합적으로 지휘하는 업무를 담당하는 것을 골자로 각 업무별 담당기관의 조정을 위한 연방-주 공동 기관이다. 또한 해상에서의 비상사태 시 연방과 주의 참여기관, 각 해운회사, 헬리콥터 회사인 Hiking-Helicopters-Service 등과의 협동이 잘 이루어지고 있으며, 동해 최대 여객선사인 독일-덴마크 선박회사인 Scandlines, ARGE Kuestenschutz와도 공조가 잘 되고 있다.

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구형용기의 하부면 냉각에 의한 해수 동결거동의 기초적 연구 (A Fundamental Study on Sea Water Freezing Behavior in a Rectangular Vessel Cooled from Below)

  • 김명준;길병래;김명환
    • Journal of Advanced Marine Engineering and Technology
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    • 제21권5호
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    • pp.564-570
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    • 1997
  • The most important factor for the desalination system is the fresh water production cost dependent upon the possible energy source which should be obtained easily and with low price. Recently in Korea the demand of LNG, as a cheap and clean energy which does not cause an environmental problem, has sharply been increased. In general, LNG is storaged in a tank as a liquid state below -162 'C. When it is serviced, however, the LNG absorbs energy from a heating source and transforms to the gaseous state with high pressure. During this process a huge amount of cold energy accumulated in LNG is wasted. This waste cold energy can be utilized for producing fresh water from sea water using a sea water freezing desalination system. In order to develop a sea water freezing desalination system and to establish its design technique, a qualitative and quantitative data regarding the freezing behavior of sea water is needed in advance. The goal of this study, therefore, are to reveal the freezing mechanism of sea water, to measure the freezing rate, and to investigate the freezing heat-transfer characteristics. The experimental results help to provide a general understanding of the sea water freezing behavior in a Rectangular vessel cooled from below.

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구형용기의 상부면 냉각에 의한 해수 동결거동의 실험적 연구 (An Experimental Study on Sea Water Freezing behavior in a Rectangular vessel Cooled From Above)

  • 최부홍
    • Journal of Advanced Marine Engineering and Technology
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    • 제22권4호
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    • pp.529-537
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    • 1998
  • Currently as due to the rapid development of industry and increase in population we meet serious problems concerning the shortage and pollution of water. In the country many experts predict a shortage of water approaching 450 million tons by the year 2006. To cope with this serious problem it is necessary to construct desalination plants. In the adoption of a desalination system the most important factor is the cost of fresh water production,. In general LNG is stored in a tank as a liquid state below $-162^{\circ}C$. When it is serviced, however the LNG absorbs energy from a heat source and transforms to a high pressure gaseous state. During this process a huge amount of cold energy accumulated in cooling LNG is wasted. This wasted cold energy can be utilized to produce fresh water by using a sea water freezing desalination system. In order to develop a sea water freezing desalination system and to establish its design technique qualitative and quantitative data regarding the freezing behavior of sea water is required in advance, The goals of this study are to reveal the freezing behavior of sea water is required in advance. The goals of this study are to reveal the freezing mechanisms of sea water to measure the freezing rate and to investigate the freezing heat-transfer characteristics,. The experimental results will provide a general understanding of sea water freezing behavior in a rectangular vessel cooled from above.

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IDENTIFICATION OF THERMODYNAMIC PARAMETERS OF ARCTIC SEA ICE AND NUMERICAL SIMULATION

  • Xiw, Chao;Feng, Enmin;Li, Zhijun;Peng, Lu
    • Journal of applied mathematics & informatics
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    • 제26권3_4호
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    • pp.519-530
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    • 2008
  • This paper studies the multi-domain coupled system of one dimensional Arctic temperature field and establishes identification model about the thermodynamic parameters of sea ice (heat storage capacity, density and conductivity) by the so-called output least-square estimate according to the temperature data acquired by a monitor buoy installed in the Arctic ocean. By the optimal control theory, the existence and dependability of weak solution and the identifiability of identification model have been given. Moreover, necessary optimality condition is proposed. Furthermore, the optimal algorithm for the identification model is constructed. By using the optimal thermodynamic parameters of Arctic sea ice, the numerical simulation is implemented, and the numerical results of temperature distribution of Arctic sea ice are demonstrated.

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A Note on the Outflow Boundary Conditions in Modeling the East Sea Circulation

  • Seung, Young-Ho;Cho, Kyoung-Ho
    • Journal of the korean society of oceanography
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    • 제33권4호
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    • pp.212-218
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    • 1998
  • Three different outflow boundary conditions are considered in modeling the East Sea circulation. The first one is that of the conventional constant volume transport (CT). The second one is the Orlanski radiation boundary condition (OR). The third one is that of the constant sea level just outside the outflow boundary (SL). In the third condition, the outflow current is set to be driven by the sea level differences across the outflow open-boundary lines, based on the recent knowledge that the Tsushima Current is driven by the sea level differences across the inflow and outflow boundaries. In case of OR it takes too much time to reach the steady state, resulting in a large increase of Tsushima Current Water in the basin and low level of kinetic energy. Both CT and SL reach the steady state in a relatively short time. However, SL is more recommendable, because it is based on physical background and generates less numerical noises than CT.

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강원도 대포항에서 구입한 연어(Oncorhynchus keta)와 송어(Oncorhynchus masou)의 Anisakid 유충감염상 및 기생윤충류에 관한 조사 (A Study About Infection State of Anisakid Larvae and Parasitic Helminths in Salmon(Oncorhynchus keta) and Sea-trout(Oncorhynchus masou) which Caught from Taep'o Port, Kang-won-do)

  • 김기홍;주경환;임한종
    • 농촌의학ㆍ지역보건
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    • 제15권2호
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    • pp.89-96
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    • 1990
  • The results of infection state of anisakid larvae and parasitic helminths in salmon and sea-trout which caught from Taep'o port. Kang-won do were as follows. 1) From twelve specimens of sea-trout. 122 individuals of anisakid larvae were found and mean infection number of anisakid larvae per individual sea-trout was 10.17. 2) From total extracted anisakid larvae from sea-trout. 37 larvae(30.3%) were found in the muscle. This percentage was lower than that of salmon. but higher than that of other sea-fishes. 3) The taxonomic list of parasitic helminths which found in salmon and sea-trout was as follows. Class Trematoda Family Hemiuridae l. Brachyphallus crenatus(Rudolphi. 1802) 2. Lecithaster salmonis Yamaguti. 1934 Class Cestoda Family Phllobothriidae 3. Pelichnibothrium speciosum Monticelli, 1889-larval form Family Tentacuariidae 4. Tentacularia sp. - larval form 4) Among those 4 species of helminths. B.crenatus. L.salmonis, P.speciosum were the first recording species in Korea.

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Annual Sea State Occurrences around the Korean Peninsula

  • Kim, Sung-Hoon;K. P. Rhee
    • Journal of Ship and Ocean Technology
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    • 제7권2호
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    • pp.20-28
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    • 2003
  • A table of annual sea state occurrences is prepared based on the significant wave heights and modal periods, two parameters representing a Bretschneider wave spectrum. Measurements of them were done by the Korean Ocean Research and Development Institute (KORDI) at 67points around the Korean peninsula for 22 years. Also the average values of parameters over 4 regions and 4 seasons were derived. Comparative seakeeping calculations using wave parameters prevalent around Korea and those of the North Pacific at sea state numbers 3, 4, and 5 respectively, show some differences in the assessed seakeeping performance.

황해에 있어서의 해양오염방지를 위한 지역적 협력에 관한 연구 (A Study on the Regional Cooperation for the Prevention of Marine Pollution in the Yellow Sea)

  • 이윤철;최성규
    • 한국항해학회지
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    • 제16권2호
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    • pp.41-52
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    • 1992
  • It is, as everyone knows, very important for human beings to protect and conserve marine environment. We has believed the ocean is so wide and deep that it cannot be polluted. But it has begun to doubt the capacity of self-purification of the ocean due to pollution arising from marine casualities. It has proved that semi-enclosed sea is likely to be polluted and cannot be restored easily once pollution occurs. Therefore, first of all it is important to take preventive measures for prevention of marine pollution in the semi-enclosed sea like the Yellow Sea. Many of regional conventions for prevention of marine pollution have come into existence. this dissertation was set out for the fact that the Yellow Sea is semi-enclosed sea which is vulnerable to marine pollution. It is desirable not to deal with marine preservation of the Yellow Sea by a single exclusively but to deal with it by cooperation of all coastal states under the present circumstances. I proposed a program of regional cooperation to protect and conserve the Yellow Sea. This program must be progressed with gradual arrangements. First, they must establist a basic cooperation committee to work basic affairs on the protection of marine environment within the Yellow Sea. The Committee Mainly play parts of study and research concerned with pollution of the Yellow Sea in the non-governmental side and consist of legal and scientific experts. Second, they must establish the control Committee to prevent marine pollution of the Yellow Sea substantially. There is a reason that regional cooperation cannot be directly concluded with the regional tready. Because there is a problem of Recognition of States left. In principle, a subject of tready must be a state in the International Law. But they have not made Recognition of State which is demanded by International Law between North and South Koreas. Therefore, the Control committee must play a substantial part of prevention from pollution instead of the treaty. Finally, we concluded tentatively named $\ulcorner$Convention on Regional Cooperation for Protection of Marine Environment of the Yellow Sea from Pollution$\lrcorner$ if the matter is settled which is related to Recognition of States in the International Law.

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정규화된 수두손실률에 의한 방조제 구간별 차수상태 평가 (The Estimation of Seepage Blocking State with the Normalized Hydraulic Head Loss Rate at Each Seepage Segment in Sea Dike Embankment)

  • 임성훈;허건
    • 한국농공학회논문집
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    • 제56권6호
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    • pp.159-167
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    • 2014
  • In this study the process of normalizing hydraulic head loss rate was developed for the purpose of estimation of seepage blocking state at each seepage segment in sea dike embankment. Pore water pressure sensors were installed with some interval along seepage path, then the hydraulic head loss rate at each segment between pore water pressure sensors was calculated, and then the calculated hydraulic head loss rate was normalized based on seepage path length. The comparison of normalized hydraulic head loss rates showed that the cross section of sea dike embankment was homogeneous approximately and the width of cross section was long enough to blocking tide water.