• International Journal of Naval Architecture and Ocean Engineering
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• 제8권4호
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• pp.375-385
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• 2016

Given the rapid progress made in understanding the dynamics of an offshore floating body in an ocean environment, the present study aimed to simulate ocean waves in a small-sized wave flume and to observe the motion of a cylindrical floating body placed in an offshore environment. To generate regular ocean waves in a wave flume, we combined a wave generator and a wave absorber. In addition, to precisely visualise the oscillation of the body, a set of light-emitting diode illuminators and a high-speed charge-coupled device camera were installed in the flume. This study also focuses on the spectral analysis of the movement of the floating body. The wave generator and absorbers worked well to simulate stable regular waves. In addition, the simulated waves agreed well with the plane waves predicted by shallow-water theory. As the period of the oncoming waves changed, the movement of the floating body was substantially different when tethered to a tension-leg mooring cable. In particular, when connected to the tension-leg mooring cable, the natural frequency of the floating body appeared suddenly at 0.391 Hz as the wave period increased.

• International Journal of Ocean System Engineering
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• 제2권4호
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• pp.214-222
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• 2012

The shipbuilding process is changing due to changes in the development environment and technological requirements for military ships. This would also hold true for a submarine, because its shipbuilding process includes complicated design and construction conditions. System improvement efforts for the design and construction of military ships have continued with the goal of overcoming these conditions. At present, the Korea Navy is developing a 3,000 ton-class Korean type submarine, and its design is progressing by the introduction of a full 3D-ship CAD system. Although the 3D modeling system was introduced for effective design realization through the introduction of collaborative design and active utilization of M&S (modeling and simulation), the introduction effects are not yet generally obvious, according to the characteristics of ship design. The present paper discusses the collaborative environment for developing a submarine to enhance this. This paper proposes the architecture and data structure of a system for realizing collaborative design and discusses a case system developed on the basis of this.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.205-213
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• 2022

A new free-living marine nematode, Chaetonema longicorpus sp. nov., was discovered in a subtidal benthic habitat around the Uljin nuclear power plant in the East Sea. Chaetonema longicorpus sp. nov. differs from other Chaetonema species in its very long body length, relatively long cephalic setae, long and narrow buccal cavity, bottle-shaped amphideal fovea, short spicules, only one pre-cloacal seta instead of a pre-cloacal supplement, and conspicuous ventral swelling at the middle of the tail. Herein, we provide a taxonomic description and illustrations of this new species using differential interference contrast microscopy. Furthermore, an illustrated pictorial key to all valid species, including the new species and comparative tables on the biogeographical and morphological characteristics of the genus Chaetonema, are provided.

• 해양환경안전학회지
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• 제16권4호
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• pp.387-391
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• 2010

유엔해양법협약과 의제21의 17장에서 해양의 통합관리를 권고한 이후 미국, 캐나다, 호주 등 선진 해양국가들은 해양법 제정과 해양정책의 수립을 통해 통합적인 해양관리를 지향하고 있다. 그러나 이들 국가는 연방정부의 체제로서 해양관련 조직의 통합과 정책의 통합에 있어 일정한 한계를 보이고 있다. 즉, 이들 국가에서는 해양관련 주관부서가 없으며, 지방정부 관할해역을 연방정부의 해양정책에 포함하지 못하고, 민간부문 관련 산업의 육성을 직접적으로 언급하지 않고 있다. 이들 연방국가의 해양정책은 범부처 및 산업계를 포함한 위원회 등을 설립하여 관련 부처 및 지방정부의 다양한 이해관계를 조정하고 있다.

• 한국제4기학회지
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• 제21권2호
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• pp.74-76
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• 2007

The modern foraminiferal distribution patterns and species diversity in surrounding seas of Korea are controlled by winter monsoon and characteristics of water masses. Abrupt climate change, Younger Dryas cold episode" is identified in Korea. The Younger Dryas is characterized by local extinctions of foraminifera. Several record-breaking climate phenomena observed in Korea, especially September, 2007.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2006년도 추계학술발표회
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• pp.163-168
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• 2006

동해의 해양 심층수 자원 기반 환경 연구의 일부로 청결기술을 적용하여 해수 중의 용존성 미량금속 (Cd, Co. Cu, Ni. Ph. Zn) 농도 분포와 변화를 조사하였다. 강원과 경북 지역에 총 6개 정점을 선정하고, 각 지역마다 최대 채수 수심 각각 200-300m 와 500m 까지 시료를 채취하였다. 본 연구의 미량금속을 위한 연안해수 표준물질 (CASS-4) 의 분석 결과 각 원소 평균 회수율은 Co의 89.4% 에서 Cd 의 99.8%의 범위였다. 용존 미량원소의 분포는 해역 및 시기적인 변화가 다양하게 나타났다 Cd, Ni, Zn의 경우는 영양염 의존형으로 표층에서 낮고 저층으로 갈수록 증가하는 경향이 뚜렷하였다. 그러나 Co, Cu, Ph 은 수직적으로 불규칙적인 분포를 나타내었다. 본 연구의 통해 심층수 원수의 중금속 농도는 해역별 수질 기준과 먹는 물 기준을 만족하였다.

• 한국해양환경ㆍ에너지학회지
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• 제7권1호
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• pp.30-34
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• 2004

동해 해양심층수의 자원적 안정성을 평가하기 위하여 2001년 3월부터 2002년 2월까지 조사한 해양조사 및 수질분석이 수행되었다. 해양심층수 시범개발해역 및 강원북부 주변해역에 대한 해양자원적 수질특성의 시공간적 변동이 분석 및 비교되었다. 특히, 자원성이 인증된 해양심층수의 안정적 공급을 위해 필요한 취수 수심의 결정을 위해 월별 수온 및 염분의 연직분포에 대한 조사해석 및 수질분석 이 이루어져 고찰되었다.

• 한국해양공학회지
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• 제15권3호
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• pp.20-27
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• 2001

After using the filtering method, wave parameters are calculated by the spectral analysis and wave by wave analysis. Extreme environments and higher wave characteristics int he Chujeon Sea are analyzed using the observed wave data. Higher wave has been intensely emphasized as an important environmental force parameter in several recent research works. The aims of this study are to summarize the distribution of extreme environment for wind waves, and to find occurrence probability of higher wave in Chujeon Sea. Ocean wave statistics varying with sea state are found to respond linearly to the spectral peakedness parameter Qp, mean run-length and Ursell number. Although the spreading of the field results is large, it may be concluded that the tendency of wave group formation depends on the spectral peakedness parameter Qp. Extreme wave is estimated to apply various model distribution functions by using the monthly maximum significant wave parameters which can be used to the design and analysis of coastal structures.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권3호
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• pp.1-13
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• 2024

This study investigated the hydrogeochemical and microbiological characteristics of freshwater on Ulleung Island, a volcanic island in the Ulleung Basin on the East Coast of Korea. The shallow groundwater (CSW, NRGW) and the surface water (SISW) samples are classified as Na-HCO₃ type, reflecting an alkaline rock type and an oxidizing environment due to the influence of a highly permeable pyroclastic rock layer. In contrast, the deep groundwater sample (DMW) is classified as Ca-HCO₃ type, suggesting the influence of deep-sourced carbon dioxide and reducing conditions. Microbial communities in the water samples are generally dominated by Proteobacteria, with the relative abundance of major genera varying depending on water quality and environmental conditions. Network analysis reveals the ecological characteristics of microbial communities adapted to specific environments. The presence of pathogenic genera in the shallow groundwater suggests potential groundwater contamination, necessitating appropriate management to ensure its use as drinking water or domestic water. The findings of this study provide valuable insights into the ecological characteristics of Ulleung Island's groundwater resources and can inform future groundwater management strategies.

• 해양환경안전학회지
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• 제20권3호
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• pp.270-276
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• 2014

Seasonal characteristics of water and sediment qualities and potential effects of the freshwater discharge from a small tide embankment interior in a coastal area in Goheung county were investigated from May to September in 2012. Chemical oxygen demand values (COD) were mostly higher than 2 mg/L in summer ebb tide, which exceed the standard value of water quality criteria II of acceptable level for aquaculture activities. Nitrogen and phosphorus were found as the limiting nutrients for algae growth in summer and fall and in spring, respectively. Nitrogen was the limiting nutrient for diatom growth in the whole studied period. The sudden high values of COD, ammonia, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) were found in water sample collected from station 5 which located in front of the tide embankment sluice gate during spring ebb tide. The freshwater discharge form the tide embankment interior maybe affected the survey areas during a short time interval. Mean values of eutrophication index of the surveyed coastal region in spring, summer and fall were all bigger than 1. Water quality was mostly considered at level II which acceptable for aquaculture activities. Sediment quality in this study was generally in the range of standard for fisheries environment.