• Ocean Systems Engineering
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• 제2권3호
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• pp.217-228
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• 2012

As the size of container ships continues to increase, not many existing harbors can host the super-container ship due to its increased draft and the corresponding dredging requires huge budget. In addition, the minimization of waiting and loading/offloading time is the most important factor in harbor competitiveness. In this regard, mobile-harbor concept has been developed in Korea to achieve much improved harbor capacity and efficiency. In developing the concept, one of the most important elements is the operability of crane between two or more floating bodies in side-by-side arrangement. The container ship is to be stationed through a hawser connection to an outside-harbor fixed-pile station with the depth allowing its large draft. The mobile harbors with smart cranes are berthed to the sides of its hull for loading/offloading containers and transportation. For successful operation, the relative motions between the two or more floating bodies with hawser/fender connections have to be within allowable range. Therefore, the reliable prediction of the relative motions of the multiple floating bodies with realistic mooring system is essential to find the best hull particulars, hawser/mooring/fender arrangement, and crane/docking-station design. Time-domain multi-hull-mooring coupled dynamic analysis program is used to assess the hydrodynamic interactions among the multiple floating bodies and the global performance of the system. Both collinear and non-collinear wind-wave-current environments are applied to the system. It is found that the non-collinear case can equally be functional in dynamics view compared to the collinear case but undesirable phenomena associated with vessel responses and hawser tensions can also happen at certain conditions, so more care needs to be taken.

• Mycobiology
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• 제50권4호
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• pp.254-257
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• 2022

Wolfiporia cocos is a wood-decay brown rot fungus belonging to the family Polyporaceae. While the fungus grows, the sclerotium body of the strain, dubbed Bokryeong in Korean, is formed around the roots of conifer trees. The dried sclerotium has been widely used as a key component of many medicinal recipes in East Asia. Wolfiporia cocos strain KMCC03342 is the reference strain registered and maintained by the Korea Seed and Variety Service for commercial uses. Here, we present the first draft genome sequence of W. cocos KMCC03342 using a hybrid assembly technique combining both short- and long-read sequences. The genome has a total length of 55.5 Mb comprised of 343 contigs with N50 of 332 kb and 95.8% BUSCO completeness. The GC ratio was 52.2%. We predicted 14,296 protein-coding gene models based on ab initio gene prediction and evidence-based annotation procedure using RNAseq data. The annotated genome was predicted to have 19 terpene biosynthesis gene clusters, which was the same number as the previously sequenced W. cocos strain MD-104 genome but higher than Chinese W. cocos strains. The genome sequence and the predicted gene clusters allow us to study biosynthetic pathways for the active ingredients of W. cocos.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제20권9호
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• pp.513-518
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• 2014

NGS 기술의 발달로 시퀀싱 비용이 급격히 하락됨에 따라 대규모 크기의 유전체 염기 서열해독을 소규모의 실험실에서 수행할 수 있게 되었다. 디노버 어셈블리는 표준 유전체가 없는 새로운 종을 시퀀싱하는 경우 리드들의 염기 서열 정보를 이용하여 재구성함으로써 원래의 전체 시퀀스를 복원하는 것이다. 최근 이와 관련된 많은 연구 결과가 보고되고 있으나, 충분한 분석 노하우와 명확한 가이드라인 등이 공개되어 있지 않기 때문에 이들 연구에서 제시하는 동일한 어셈블리 수행 과정 및 분석 툴들을 사용하더라도 만족할만한 수준의 어셈블리 결과를 얻지 못하는 경우가 발생한다. 본 연구에서는 이러한 문제점을 해결하기 위하여 NGS 기술과 디노버 어셈블리 기술을 이용하여 아직 밝혀지지 않은 생물체의 전체 DNA의 염기 서열을 밝히기 위한 일련의 과정들을 단계별로 소개하고, 각 단계에서 필요로 하는 공개용 분석 툴의 장단점을 분석하여 제시한다. 이러한 과정별 단계를 구체적으로 설명하기 위하여 본 연구에서는 350Mbp 크기의 개 회충 게놈을 응용 사례로 사용한다. 또한 디노버 어셈블리 과정을 통해 새롭게 어셈블리된 시퀀스와 다른 유사 종과의 상동성 분석을 수행하여 어셈블리된 시퀀스에서의 유전자 영역 추출과 추출된 유전자의 기능을 예측한다.

• 환경영향평가
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• 제20권3호
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• pp.397-409
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• 2011

This study was carried out for improving the effectiveness of water resources development project through local resident opinions in the environmental impact assessment(EIA). The EIA reports of seven dams were examined. Four dams -Youngju Dam, Seongduck Dam, Buhang Dam and Hantangang Dam- which included many local opinions including 470 opinions of 341 local residents were selected to be analyzed. Local residents submitted their opinions in the six fields which are meteorological phenomena, water quality, land use, fauna and flora, noise and vibration, and residence, and the major opinions of those opinions came from the atmosphere environment field which is 32% of total opinions and social and economic field which is 38% of total opinions, respectively. In submerged area, opinions of the measure for migration and compensation were 91% and in non-submerged area, opinions of the measure for meteorological phenomena was 86%. Those percentages were maximum in each area. Opinions concerned meteorological phenomena were 86% and 53% in Youngju Dam and Seongduck Dam where area is surrounded by existing dam, but there was only 9% and 0% of opinions in Buhang Dam and Hantangang Dam where area is without existing dam nearby. The reformation methods which reflected the resident's opinions were suggested on EIA in dam development projects. First of all, reliability and objectivity of the field of meteorological phenoma should be enhanced by scientific prediction of the phenomenon days. Secondly, techniques reducing uncertainty of various water quality prediction models ought to be developed and effectiveness of the reduction strategies in environmental impact should be quantified. Finally, the draft of EIA report should involve the detailed plans of migration and compensation's procedures, criteria and measures to support.

• 대한조선학회논문집
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• 제41권6호
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• pp.1-7
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• 2004

Recently, very large container ships are emerging as shipment of containers is expected to rapidly increase near future. A possibility of roll resonant motion in a seaway is expected to noticeably increase for large container ships of which capacity ranges 8,000 to 15,000 TEU due to relatively wide breadth and shallow draft comparing to conventional container ships. In this paper, a design and performance evaluation of a fin stabilizer for a 9,000 TEU container ship is carried out. The weak opposed control concept is adopted for the design. Time domain simulations and model tests are performed for performance evaluation. The design prediction, the model tests and the simulations show generally good agreements.

• 설비공학논문집
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• 제26권3호
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• pp.130-136
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• 2014

The present study is performed to set up the framework of cooling tower performance predictions. The performance of mechanical forced draft cooling tower is directly related to the state of a nuclear power plant system, such as the condenser and evaporator. The main parameters related to the state of systems are as follows : wet bulb temperature, dry bulb temperature and absolute humidity. The performance evaluation of cooling tower must be considered at the power plant design. In this study, the toolkit developed by the American Cooling Tower Industry association (CTI) has been used for the framework construction. In order to validate the framework, it is being applied to the cooling tower constructed for the U.S. Nuclear Power Plant. The test results have shown good agreements with the cold water temperature on the cooling tower performance curves provided by manufacturers.

• 설비공학논문집
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• 제8권3호
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• pp.361-374
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• 1996

In general, a cooling tower has two major noise sources, one is the fan and the other is the falling water. The fan noise is produced by passage of its blades through the air and radiates from the fan stack. Noises from the falling water are caused by splashing and dropping of water cascading over the internal filler of the cooling tower and into the basin and radiate from the louvered face. In this paper, the noise measurements and its frequency analysis are carried out for the locations facing the louvered side and near the fan stack referring the related code and standards in order to study the noise characteristics of the induced-draft cooling tower, especially for the buildings. As a result, it is found that for every doubling of distance from the noise source the noise level decreases by 2~4dBA in the near field with reflect surfaces and decreases by about 6dBA also in the far field without reflect surfaces. As a supplement to the noise measurements, a computer program with simple algorithm is developed in order to estimate the noise level at a distance from the cooling tower, so that the user could apply and modify it for the particular boundary conditions easily.

• 수산해양기술연구
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• 제55권3호
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• pp.273-283
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• 2019

The authors has predicted the maneuvering characteristics of a fishing vessel in deep water using Kijima's empirical formula in a previous study. Since the Kijima's empirical formula was developed by a regression analysis of merchant vessels which have dimensions ($C_b$, L/B, etc.) that are different from those of fishing vessels, it was possible to make a prediction approximately even with inaccurate estimation. In this study, the authors estimated the turning-motion characteristics of a model ship of fisheries training ship in shallow water based on the results of its previous study. The turning-motion characteristics of the model ship in shallow water was found out through quantitative analysis according to the water depth to ship draft ratio (H/d). In conclusion, the turning-motion characteristics of the model ship had significant changes immediately after an H/d 1.5, and this result will be helpful for sailing in shallow water.

• Journal of Advanced Marine Engineering and Technology
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• 제40권7호
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• pp.574-579
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• 2016

기존의 연구에서 저항 성능을 정도 높게 추정하던 격자 시스템은 모형선의 길이 6-8m, 동적 트림 ${\pm}1^{\circ}$ 이하인 일반 대형 상선에 최적화되어 있다. 이러한 격자 시스템을 소형 어선과 같이 프루드 수 0.3~0.8, 동적 트림이 ${\pm}3^{\circ}$ 이상인 대상선에 적용할 경우 수치적 불안정성을 야기한다. 본 연구에서는 이러한 문제를 해결하기 위해 부심으로부터 입구 경계 조건의 길이를 줄이고, 자유수면의 각도에 따라 밀집된 격자 형태를 갖는 격자 시스템을 구성하였다. 상기 격자 시스템을 이용하여 설계 흘수와 밸러스트 흘수에서 다양한 선속에 대해 어선에 작용하는 저항을 수치 해석으로 계산하였으며, ITTC-1978 2차원 해석법을 이용하여 소형 어선의 유효마력을 추정하였다. 준추진효율 계수는 기존의 모형시험 자료를 활용하였으며, 설계 흘수에서 제동마력 추정을 통해 속도 성능을 평가하였다.

• 한국해안해양공학회지
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• 제18권2호
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• pp.97-111
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• 2006

고유함수전개법을 이용하여 다열 커튼월-파일 방파제로부터의 규칙파의 반사율과 투과율을 계산할 수 있는 수학적 모형을 제안하였으며, 파일 부분의 유공율, 커튼월의 흘수 그리고 방파제 열 사이의 간격 등을 다르게 하면서 수리모형실험을 실시하였다. 상대수심이 감소하면서 반사율은 감소하고 투과율은 증가하는 경향을 보이다가, 상대수심이 아주 작아지면 반사율은 다시 증가하고 투과율은 감소하는 경향을 보였다. 다른 실험 변수들은 고정시킨 상태에서, 커튼월의 흘수만 변화시키거나 파일 부분의 유공율만 변화시키는 경우에는 반사율과 투과율의 상대적인 크기는 달라지지만 전반적인 거동은 유사했다. 입사파의 파장과 열 사이의 간격이 일치하는 경우에는 반사율과 투과율이 급격하게 변화하였다. 3열로 구성된 방파제의 경우에도 수학적 모형과 실험 결과가 대체로 잘 일치하였다.