• Ocean and Polar Research
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• 제25권1호
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• pp.21-30
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• 2003

Seasonal fluctuations of physico-chemical and biological aspects of the environment were studied in Vladivostok harbour (Golden Horn Bay, the East Sea/Sea of Japan). The benthic community structure was described with a focus on size-spectra (bacteria, meio- and macrofauna) related with the chemical environment and chemical fluxes in sediment and to reveal their possible ecological role in the process of bioremediation of the environment. Samples from two sites with different concentrations of heavy metals (Fe, Zn, Cu, Pb, Mn, Cr, Ni Cd, Co) and petroleum hydrocarbon were assessed by a number of methods. These included plate counts of culturable bacteria, observation through a scanning electron (SEM) and transmission electron microscope (TEM). These approaches were complemented with microscopic assessments of the diversity of the benthic community. The specific communities had a limited number of species, tolerant to abnormally high levels of toxic compounds. The dominant species were presented by several sho.1-lived small polychaetes (Capitella capitata) and nematodes (Oncholaimium ramosum). The highest population density was recorded in microbenthos, in various diatoms, various physiological groups of bacteria which participate in biomineralization: marine heterotrophic bacteria, which oxidized oil, black oil in addition to groups resistant to heavy metals. They have the entire set of mechanisms for neutralizing the negative effect of those compounds, forming the detrital food web and biogeochemical circulation of material in sediments, which results in the biological self-recycling of sea basins. Macro- and meiobenthic organisms were more sensitive to a greater extent of $H_2S$ and petroleum hydrocarbons than to metal content, but the within-site rankings were the same as those achieved for microbiological analyses.

• Strategy21
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• 통권45호
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• pp.60-90
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• 2019

공해의 이용은 '항해의 자유'와 '기국주의'라는 관습법으로 형성되어온 원칙이 유엔해양법협약에서 명문화되어 공해 이용에 관한 두 개의 큰 축을 이루고 있다. 연안국의 해양에 대한 통제권이 확대되고 새로운 안보위협에 대처하기 위한 레짐이 생성되면서 공해의 자유에 관한 두 가지 기제를 축소하려는 유인과 시도가 있었다. '항해의 자유'와 '기국주의'는 인류가 바다에 진출한 이래 수 천 년에 걸쳐 형성된 관습법이고 오늘날 인류 공동의 유산인 바다를 평화롭고 질서 있게 이용하기 위한 법, 제도적 근간이 되고 있다. 따라서 공해상 타국 선박에 법 집행의 절차적 편리성과 집행국의 이익을 위해 이러한 원칙으로부터 예외를 만들거나 후퇴하기 시작하면 해양이용의 기본 틀 자체가 위협받을 수 있고 결국에는 해양질서는 강대국의 힘의 논리와 이익에 좌우 될 수 있다. 이러한 이유로 대북해상 제재와 같은 새로운 해양법 집행 레짐이나 조치는 무해통항제도, 공해이용의 자유와 같은 원칙을 존중하고 국제법의 틀 안에서 이루어져야 한다.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.604-610
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• 2007

A psychrotrophic strain 7195 showing extracellular lipolytic activity towards tributyrin was isolated from deep-sea sediment of Prydz Bay and identified as a Psychrobacter species. By screening a genomic DNA library of Psychrobacter sp. 7195, an open reading frame of 954 bp coding for a lipase gene, lipA1, was identified, cloned, and sequenced. The deduced LipA1 consisted of 317 amino acids with a molecular mass of 35,210 kDa. It had one consensus motif, G-N-S-M-G (GXSXG), containing the putative active-site serine, which was conserved in other cold-adapted lipolytic enzymes. The recombinant LipA1 was purified by column chromatography with DEAE Sepharose CL-4B, and Sephadex G-75, and preparative polyacrylamide gel electrophoresis, in sequence. The purified enzyme showed highest activity at $30^{\circ}C$, and was unstable at temperatures higher than $30^{\circ}C$, indicating that it was a typical cold-adapted enzyme. The optimal pH for activity was 9.0, and the enzyme was stable between pH 7.0-10.0 after 24h incubation at $4^{\circ}C$. The addition of $Ca^{2+}\;and\;Mg^{2+}$ enhanced the enzyme activity of LipA1, whereas the $Cd^{2+},\;Zn^{2+},\;CO^{2+},\;Fe^{3+},\;Hg^{2+},\;Fe^{2+},\;Rb^{2+}$, and EDTA strongly inhibited the activity. The LipA1 was activated by various detergents, such as Triton X-100, Tween 80, Tween 40, Span 60, Span 40, CHAPS, and SDS, and showed better resistance towards them. Substrate specificity analysis showed that there was a preference for trimyristin and p-nitrophenyl myristate $(C_{14}\;acyl\; groups)$.

• 한국전산구조공학회논문집
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• 제25권1호
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• pp.27-36
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• 2012

모바일하버는 선박의 대형화로 인하여 항만에 접안 및 정박이 불가능하거나 선박의 접안 대기시간이 길어지는 경우 등 항만의 문제점들을 해결하기 위해 제시된 새로운 개념의 시스템이다. 이 새로운 시스템은 해상에 있는 선박에 다가간 후, 모바일하버에 설치된 크레인을 이용하여 선박에 컨테이너를 직접 상, 하역작업을 하도록 고안되었다. 모바일하버용 크레인은 컨테이너를 이송하는 장치로써 그 중요성이 매우 크다. 본 연구에서는 모바일하버용 크레인의 형태들을 제시하고 각 형태에 따른 구조최적설계를 실시하였다. 불안정한 해상으로부터 발생되는 횡동요 및 종동요와 바람에 의한 풍하중을 최적설계의 하중조건으로 하였다. 또 한국선급 및 각각의 규정들을 최적설계의 제한조건으로 하여 규정을 만족하면서 경량화된 크레인 구조를 최적화하였다.

• 대한조선학회논문집
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• 제50권4호
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• pp.217-223
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• 2013

This paper presents the wet damping estimation of the segmented hull model using the random decrement technique together with the continuous wavelet transform. The tested 16 sea states are grouped together based on the speed of the ship in order to figure out the possible influence of the ship speed on the damping ratio. The measured time histories of vertical bending moment for each tested sea state were processed with random decrement technique to derive the free decay signal, from which the damping ratios are estimated. Also, the autocorrelation functions of the filtered signal were calculated and comparison was made with the free decay signal obtained from the random decrement technique. Then the wet damping ratios for each sea state group, as well as precise wet natural frequencies, are estimated by using continuous wavelet transform. It turned out that the wet natural frequencies derived from the measured signal did not show any significant discrepancy compared with those obtained by wet hammering test, whereas the damping ratio did. It was considered that the discrepancy of the damping ratio between in calm and moving water may be attributed to the viscous effects caused by dramatically different flow pattern and relative velocity between the vibrating structure and surrounding fluid particles.

• 한국해양공학회지
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• 제33권3호
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• pp.214-221
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• 2019

A series of model tests was performed to evaluate the survivability of an articulated tower-type buoy structure under harsh environmental conditions. The buoy structure consisted of three long pipes, a buoyancy module, and top equipment. The scale model was made of acrylic pipe and plastic with a scale ratio of 1/22. The experiments were carried out at the ocean engineering basin of KRISO. The performance of the buoy structure was investigated under waves only and under combined environmental conditions from sea state (SS) 5 to 7. A nonlinear time-domain numerical simulation was conducted using the mooring analysis program OrcaFlex. The survivability of the buoy was analyzed based on three factors: the pitch motion, submergence of the top structure, and anchor reaction force. The model test results were directly compared to the results of numerical simulations. The effects of the sea state and combined environment on the performance of the buoy structure were investigated.

• 대한조선학회논문집
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• 제61권5호
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• pp.297-311
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• 2024

In this study, a combined seakeeping performance evaluation method has been developed for the design purpose of the light aircraft carrier CVX of Korean Navy. A frequency domain analysis method was developed for evaluation of safe operating envelope up to sea state 6, while a time domain analysis method was developed for survival condition of sea state 7 and higher. The frequency-domain solver AdFLOW-Navy was developed by adding empirical formula of roll damping and fin-stabilizer to the existing AdFLOW by KRISO, which was based on the three-dimensional higher order boundary element method (HOBEM). For the estimation of the roll damping coefficient, a two-dimensional cross-section was automatically extracted from the three-dimensional panel, and the roll damping coefficient was analyzed for the two-dimensional cross-section. As for the time domain analysis method, KIMAPS-Navy was developed by improving and expanding the KIMAPS series developed by KRISO which is based on the impulse response function by utilizing the hydrodynamic coefficients obtained from the AdFLOW-Navy. In addition, a weakly nonlinear analysis approach was applied to analyze highly nonlinear motion under heavy sea states. Finally numeraical analysis results were compared with model tests, which showed practical usefulness of the present combined seakeeping analysis approach.

• Ocean and Polar Research
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• 제44권2호
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• pp.147-160
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• 2022

SRFC (Sub-Regional Fisheries Commission) requested to the ITLOS (International Tribunal for the Law of the Sea) an advisory opinion relating to the IUU (Illegl, Unreported, and Unregulated) fishing (Case No-21 of the ITLOS). Since, in the UNCLOS, there is no article authorizing the jurisdiction of the ITLOS full court's Advisory opinion, so various scholarly opinion wad divided. But ITLOS delivered its Advisory opinion confirming its jurisdictional competence over the Advisory proceedings with its legal opinion about the IUU issues. It opens new possibility of the alternative dispute settlement mechanism of the ITLOS through the advisory procedures. In reality, there has been a view that ICJ (International Court of Justice) could take the part of a kind of dispute settlement through its Advisory procedures. But the advisory procedures of the ITLOS, with no definite clause in UNCLOS about the advisory procedures, which provides more allowances for the function of advisory opinion as the alternative dispute settlement mechanism. ITLOS accepted the requests of the advisory opinion by the State parties through international organization or themselves directly. And the advisory opinion of the ITLOS aims the interpretation and application into the special issues-specially IUU fishing in Case No. 21 of the ITLOS-. Those factors could enable more enhanced role of the ITLOS as an alternative dispute settlement mechanism. But those possibility has contain risk of excessive and unlimited advisory role of the ITLOS. So it is important to focus on the restriction on the role of the State parties in the request of the advisory opinion to the ITLOS. In this regard it is meaningful that the ITLOS has suggested a kind of legal standing in the advisory procedures in that only coastal States could request the Advisory opinion about the IUU in their EEZ. Furthermore the discretionary power of the ITLOS in the Article 138 of the Rules of the Tribunal could curtail the abuse of the Advisory opinion initiated by the States parties of the UNCLOS. Under this framework, Advisory opinion could broaden more alternative option to the disputes between State parties of the UNCLOS in that after being delivered detailed interpretation of the UNCLOS about the specific issues, States parties could devote themselves to searching for flexible solution for the disputes between State parties. It could obtain legal explanation about the dispute under the Article 297 and Article 298 by detouring the jurisdiction limits through advisory procedures.

• 한국지구과학회지
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• 제23권6호
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• pp.474-485
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• 2002

본 연구의 목적은 전라남도 완도군 고금도 지역 지하수의 수리지구화학과 수소-산소동위원소를 파악하여 해수침투경로와 오염여부를 규명하는데 있다. 연구지역 지하수의 물리적인 특성은 중성과 전이환경에 속하며, 해수와 지표수의 영향을 받은 것으로 나타났다. 화학적인 특성에서도 해수의 침투, 육상의 오 ${\cdot}$ 폐수 및 농약이나 폐기물에 의해 오염이 진행되고 있다. 특히 지하수 중 여섯 지역에서 Cl은 먹는 샘물 기준치를 초과하는 것으로 나타났다. 파이퍼도에서 GG-4와 14지역은 해수의 침투로 오염되었으며, 수질유형을 구분하여 보면 GG-3, 7 및 13지역은 Na와 HCO$_{3}$가 지배적이고, GG-14지역은 해수와 같이 Na와 Cl이 지배적으로 나타났다. 수리지구화학적인 모델링 분석결과 해수의 방해석과 백운석 포화지수는 과포화상태이며, GG-3, 14 및 18지역에서 포화영역에 접근하고 있다. 수소-산소동위원소비에서 본 역 지하수의 기원은 순환수이며, GG-1, 5 및 14지역의 높은 산소동위원소는 지표수의 유입과 해수 침투에 의한 것이다. 본 연구결과 GG-14지역의 지하수는 해수의 침투에 의해 오염되어 있으며, GG-3, 7 및 13지역을 제외한 지하수들은 해수의 침투 및 인위적인 오염원에 의해 오염이 진행되고 있다.

• Ocean Systems Engineering
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• 제3권1호
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• pp.71-77
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• 2013

The effective tracking area of ultra short baseline (USBL) systems strongly relates to the safety of autonomous underwater vehicles (AUVs). This problem has not been studied previously. A method for determining the effective tracking area using acoustic theory is proposed. Ray acoustic equations are used to draw rays which ascertain the effective space. The sonar equation is established in order to discover the available range of the USBL system and the background noise level using sonar characteristics. The available range defines a hemisphere like enclosure. The overlap of the effective space with the hemisphere is the effective area for USBL systems tracking AUVs. Lake and sea trials show the proposed method's validity.