• 한국해안해양공학회지
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• 제19권4호
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• pp.320-328
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• 2007

해양콘크리트구조물의 내구성은 일반적으로 해수의 침식 작용과 콘크리트 내부로 침투하는 염분의 확산에 따른 부식에 의해 크게 피해를 입으며, 이러한 내구성 저하는 해양콘크리트구조물의 과다한 유지 관리비를 초래하게 된다. 따라서 해양구조물의 내구성 증진을 위하여 고내구성 재료의 사용이 검토되고 있다. 본 연구에서는, 광물질 혼화재(실리카흄, 플라이애쉬, 고로슬래그미분말)와 표면처리 철근(스테인리스 봉강, 에폭시 코팅) 그리고 부식억제제를 사용한 해양콘크리트의 부식저항 특성을 전기화학적기법을 이용하여 비교 검토하였다. 또한 고내구성 재료사용에 따른 내구성 증진효과를 정량적으로 제안하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제17권4호
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• pp.63-72
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• 1993

This paper deals with the determination of the main design parameters on the efficient .betha. type stirling engine for marine use having the rhombic drive mechanism. This studies are performed as following. (1) The characteristics of $\beta$ type stirling engine, (2) The kinds of driving mechanism, (3) The structure of rhombic drive mechanism, (4) The reasons of making choice of the rhombic drive mechanism in $\beta$ type stirling engines, (5) Ultimately the purpose of this paper is to determine the main design parameters of $\beta$ type stirling engines for marine use having the rhombic drive mechanism. Finally, We can adapt the result of this paper in designing of $\beta$ type stirling engine driven by the rhombic drive mechanism.

• 해양환경안전학회지
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• 제7권3호
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• pp.107-116
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• 2001

The relatively rapid rising trends of crime rates in marine situations leads to social concerns in Korea. This study reviews some theoretical backgrounds of the economics of crime and apply econometric models to Korean marine crimes. We find that there is a positive relationship between marine crime rates and unemployment rates in Korea and the degree of the relationship is higher in the 1990s' in comparison with the results of 1970s' and 1980s'. This findings are compatible with the previous theoretical researches in advanced countries. These findings show that recently the structure of our economy and the economic behaviors of economic agents in Korea have been similar to those of the advanced economies. Therefore this study shows that there exists the additional social costs of economic depression by causing the social crimes and the necessity of public policies to reduce unemployment rates would be higher.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
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• pp.214-214
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• 2011

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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• pp.107-107
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• 2011

• Journal of Advanced Marine Engineering and Technology
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• 제19권4호
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• pp.7-16
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• 1995

This article describes the working prnciple, structure and main characteristics of vacuum coolers for vegetables, and gives concrete examples of vacuum coolers that srebeing put to practical use. In particular, newly-developed cavuum coolers with cold storage, utilizing night-time electricity, are focused upon. Processing plants for vegetables, cold-storage rooms and vacuum cooling devices were investigated as possible application of vacuum cooling technology.

• Journal of Welding and Joining
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• 제6권3호
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• pp.43-55
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• 1988

An experimental study was carried out to identify the fatigue fractue behavior of weld zone in generally rolled steel for marine structure. The bending an shear loads were applied simultaneously on the specimens to simulate real load condition for marine structure. The effect of the stress intensity factor under mode I with II loading condition on the initiation and the propagation of a crack were investigated, with particular emphaiss on mode II. When the $K_{II}$ stress intensiy factor in mode II was applied under mode I load condition, the growth behavior of a crack seems to be affected mainly by the anisotropic characteristic of materials. Especially, when the crack was located in and near the weld zone and parallel to th weld line, the propagation behaviour was turned out to be quite different from that of the base metal along the direction transverse to the weld line. In general, the propagation veiocity of the cracks in and near the weld zone was found to be slower that the velocity in base metal.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권4호
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• pp.439-449
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• 2018

In this paper, multi-objective optimization of a multi-bubble pressure cabin in the underwater glider with Blended-Wing-Body (BWB) is carried out using Kriging and the Non-dominated Sorting Genetic Algorithm (NSGA-II). Two objective functions are considered: buoyancy-weight ratio and internal volume. Multi-bubble pressure cabin has a strong compressive capacity, and makes full use of the fuselage space. Parametric modeling of the multi-bubble pressure cabin structure is automatic generated using UG secondary development. Finite Element Analysis (FEA) is employed to study the structural performance using the commercial software ANSYS. The weight of the primary structure is determined from the volume of the Finite Element Structure (FES). The stress limit is taken into account as the constraint condition. Finally, Technique for Ordering Preferences by Similarity to Ideal Solution (TOPSIS) method is used to find some trade-off optimum design points from all non-dominated optimum design points represented by the Pareto fronts. The best solution is compared with the initial design results to prove the efficiency and applicability of this optimization method.

• ALGAE
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• 제18권4호
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• pp.311-320
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• 2003

The community structure of benthic marine algae was investigated at Taean Thermal Power Plant and other places around Taean Peninsula, the west coast of Korea. Total of 100 species including 3 Cyanophyta, 14 Chlorophyta, 18 Phaeophyta, and 65 Rhodophyta were identified. The number of species was highest with 78 species at the Power Plant intake, followed by 61 at the discharge, 56 at Bunjeondo, and 50 at Maoe. It was noteworthy that a subtropical species Caulerpa okamurae was collected at the intake in autumn and it was the first observation in the west coast of Korea. The pattern of vertical algal distribution showed Gloiopeltis furcata occurred in the upper intertidal zone, Sargassum thunbergii and Corallina spp. in the middle and lower zone and Enteromorpha spp. in the lower middle zone. These were all dominant species except for Enteromopha spp., which was subdominant species. Other subdominant species were Chondrus ocellatus and Neorhodomela aculeata. The average diversity indices were between 0.70 and 1.20 at each area based on their dry weight. The similarity index was 0.79 between the algal flora of this study and that of 1987, indicating that the condition of the benthic environment remained unchanged since then. This area maintained its environmental quality, so the algal community remained same with similar structure. This study area seemed a suitable place for long term monitoring of the benthic environment where industrial facilities such as a power plant might affect the benthic algal community.

• Ocean and Polar Research
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• 제23권2호
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• pp.63-75
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• 2001

Species composition and community structure of the fouling found on the hulls of 28 ships traveling through 6 main shipping routes (SR)in the Far East Sea Basin were analyzed using statistical methods. Samples obtained during 1976-1990 expeditions of the Institute of Marine Biology were used for the analyses. These samples were taken from the ships anchored in the harbor by SCUBA diving and in dry-docks of the Vladivostok ship-repairing yard. Similar composition of the fouling communities occurred on the ships travelling the same SR. In five cases, fouling was dominated by different Cirripedia communities. And, in one case, a community of the mussel Mytilus trossulus was found. In most cases the results of the factor analyses showed extremely low level of the relationships among different animals and algal species in fouling communities. Each ocean-going ship had an original structure of the fouling. Spatially disconnected animal associations of tropical and boreal origin may simultaneously coexist at the same ship. This paper testified to the originality of the zone of anthropogenic substrata as a benthos concentrator in the pelagic regions of the world ocean. The fouling from different zones showed that each zone possesses peculiar features and regularities of the composition and relationships between organisms dwelling here.