• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2002년도 춘계학술대회논문집
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• pp.39-51
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• 2002

Online exchange is a cost-effective approach to trade goods and information among multiple sellers and buyers. Shipping industry includes lots of global entities such as shippers, liners, ship owners and shipping agents. Marine insurance companies and ship repairers and many other groups are also supporting the industry. However, international shipping exchanges are located on few cities in the world. Its our motivation that a shipping market can be online so that market participants do the dealing while sitting where they are with more efficient manner, preferable price and larger pool of candidates of trading partners. This paper presents Korean governmental project of building a cyber shipping exchange. The exchange covers ship sale and purchase, charter, insurance, freight futures, repairs, supplying of ships oil and database service. The workflows of each business were analyzed and designed to fit for online environment. The project includes design of trading mechanism, online documents, data flow, data storage and security. Online match making and trading mechanisms such as auction, reverse auction, bid are used. The whole trading process involves multiple organizations and business processes. So, this Paper focuses on how each organization would play their roles so that users can complete transactions with integrated and transparent view. The online exchange selves also as maritime portal site that links to other sites for cooperation vertically or horizontally, and serves database and information in global perspective. This paper also issues and discusses the justification of an online shipping exchange

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 추계학술대회
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• pp.205-207
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• 2015

LNG/LPG는 폭발가능성이 크기 때문에 매우 위험한 물질이다. LNG/LPG는 gas상태의 연료를 극 초저온에 고 압력 상태로 고농축한 액체 연료이다. 온도나 압력에 따라 물질의 상태가 변하기 때문에 폭발이나 화재가 일어날 수 있다. 하지만 무조건 사고가 일어나는 것은 아니며 현재까지도 화재나 폭발이 일어난 경우가 드물다. LNG/LPG선박은 충돌이나 파손 등 사고위기가 클수록 위험하다. 사고위기가 일어나는 요소로는 복잡한 항로, 많은 선박 수, 해마다 증가하는 LNG/LPG의 수요량 등이 있다. 본 연구에서는 LNG/LPG관련 해양사고 시나리오를 만들기 위해 사고 연계 고리(Accident chain)를 만들어 분석하였다. 해양사고의 연계 고리를 만들기 위해서는 story가 필요하다는 것을 알게 되었고, Risk를 통해 Peril과 Hazard를 분석 할 수 있었다. LNG/LPG의 위험성은 고압에 기인하는 위험, 화재위험, 동상위험, 화학반응의 위험, 질식 위험 등으로 분류 할 수 있었다. 아직까지는 LNG/LPG선박의 화재 및 폭발사고는 거의 일어나지 않았으나 매년 그 수요량이 증가하고 있고, 매우 위험한 물질임을 본 연구를 통해 알 수 있었다.

• 대한조선학회논문집
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• 제45권6호
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• pp.646-655
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• 2008

A main issue about production management of shipyards is to efficiently manage the work in process and logistics. However, so far the management of a transporter for moving building blocks has not been efficiently performed. To solve the issues, optimal block transporting scheduling system is developed for minimizing of the travel distance without overload of a transporter. To implement the developed system, a hybrid optimization algorithm for an optimal block transportation scheduling is proposed by combining the genetic algorithm and the ant algorithm. Finally, to evaluate the applicability of the developed system, it is applied to a block transportation scheduling problem of shipyards. The result shows that the developed system can generate the optimal block transportation scheduling of a transporter which minimizes the travel distance without overload of the transporter.

• 대한조선학회논문집
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• 제45권6호
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• pp.590-600
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• 2008

This paper concerns the development of a designer friendly hull form parameterization and its coupling with advanced global optimization algorithms. As optimization algorithms, we choose the Partial Swarm Optimization(PSO) recently introduced to solve global optimization problems. Most general-purpose optimization softwares used in industrial applications use gradient-based algorithms, mainly due to their convergence properties and computational efficiency when a relatively few number of variables are considered. However, local optimizers have difficulties with local minima and non-connected feasible regions. Because of the increase of computer power and of the development of efficient Global Optimization (GO) methods, in recent years nongradient-based algorithms have attracted much attention. Furthermore, GO methods provide several advantages over local approaches. In the paper, the derivative-based SQP and the GO approach PSO are compared with their relative performances in solving some typical ship design optimization problem focusing on their effectiveness and efficiency.

• Journal of Microbiology
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• 제39권2호
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• pp.133-138
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• 2001

We investigated the antagonism of indigenous bacteria isolated from stressed mussels and their extracellular metabolites on the adult zebra mussel, Dreissena polymorpha. Selective bacterial isolates including Aeromonas media, A. salmonicida, A. veronii, and Shewanella putrefaciens, showed strong lethality against adult mussels and 100% mortality was observed within 5 days of incubation. Bacterial metabolites, fractionated and concentrated from stationary-phase culture supernatants of these bacterial isolates, displayed varying degrees of antagonistic effects on zebra mussels. Among the three size fractions examined, <5, 5-10, and >10 kDa, the mast lethal fraction seems to be >10 kDa for three of the four isolates tested. Further chemical analyses of these size fractions revealed that the predominant constituents were polysaccharides and proteins. No 2-keto-3-deoxyoctanoic acid (2-KDO), deoxyribonucleic acids (DNA) or uranic acid were detectable. Extraction of supernatants of two antagonistic isolates with polar solvent suggested that polar molecules are present in the active fraction. Our data suggest that extracellular metabolites produced by antagonistic bacteria are also involved in disease development in zebra mussels and elucidation of the mechanisms involved may offer a novel strategy for control of biofouling invertebrates.

• The Korean Journal of Ecology
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• 제5권4호
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• pp.187-203
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• 1982

The results obtained from te field investigations of Chuja Island conducted for 5 days from July 18 to 22, 1980 and from August 12 to 16, 1981 are summarized as follows: Vascular plants of this island disclosed by the present study consisted of 86 families, 210 genera, 228 species, 38 varieties and 4 래금. Nineteen species of evergreen broad-leaved trees were discovered, including Litsea japonica Juss, Camellia japonica L. and Machilus thunbergii Sieb. et Zucc. These indeciduous latifoliate trees were preserved in poor condition. Ten-twenty years old Pinus thunbergii was confirmed to be the predominant species. Seaside plants encountered were 6 species, including Vitex rotundifolia L. Fil. and Asterspathullfoius Max., but they were poorly distributed. Naturalized plants comprised a total of 12 species. This varied number of species is considered attributable to the frequent access of men owing to convenient marine traffic. the destruction of vegetation of this island may be attributed to human interference (loggin for boat construction, building and charcoal materials) ever escalated by high population density. It is worthy of noting that Bochmeria penosa Nakai et Stake which forms a large community in this island can be used as textile resources.

• 한국통신학회논문지
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• 제35권8B호
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• pp.1217-1223
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• 2010

최근 선박의 기술 패러다임이 신개념 디지털 선박으로 이동하면서 IT기술이 결합된 고부가가치 조선산업을 창출할 수 있는 경쟁력 있는 IT조선 융복합 기술개발과 인력양성은 매우 중요하다. 본 논문에서는 IT조선융복합 전문인력을 양성하기 위한 교육 프로그램을 소개한다. 용복합 교과목 구성은 조선산업체를 대상으로 IT조선기술 수요조사를 실시하여 IT분야는 해상무선통신기술분야, 선박용 S/W솔루션기술분야, CAN and SAN 분야로 나누고 조선분야는 조선설계분야, 선박건조분야로 나누어 교과목을 도출하였다. 융복합 교육 프로그램 운영은 모든 부분에서 산업체 전문가를 투입하여 산업체 현장의 실무능력이 향상되고 바로 산업체에 투입할 수 있는 인력양성을 목표로 추진되었다.

• Strategy21
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• 통권44호
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• pp.54-78
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• 2018

The core of the current constitutional amendment pursued by the Abe administration depends on the status of the Japanese Self-Defense Forces, which include the right to engage in war, in the legal and regular military positions. This is an important turning point for the Abe administration, which aims to become a normal country for Japan, and it is a series of steps that followed in the revision of the U.S. and Japan guidelines in 2015 and the overhaul of the security law in 2016. In this paper, we propose building "A navy Attractive to Alliances" as a way to secure Korea's maritime security under the current security environment. The term "attraction" refers to the alliance "first priority" especially in the United States. The way to do this is to transform the paradigm of the ROK-U.S. alliance into a naval hub in the vast seas, which will allow us to strengthen our national defense and even deter threats from neighboring countries. To this end, our navy needs to have a more active approach to U.S. East Asian strategy. If we can convince the United States to be a nation that contributes more to its East Asian strategy, it will only lead to a strengthening of the status of its alliance and expansion of its unilateral support and military capability against Japan, thus minimizing Japan's influence.

• 한국항해항만학회지
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• 제36권7호
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• pp.545-552
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• 2012

Domestic marina facilities today consist mostly of composite-type marinas with particular spatial composition characteristics, due to the regulatory restrictions that keep their development in the public sector and the tepid growth of marine leisure-sports. To develop a marina club design appropriate for domestic conditions, this study establishes space program standards for designing Korean marinas based on a case analysis of existing marina clubs and a survey of floating marina clubs. It is possible for a current composite-type Korean marina club to have a spatial composition of 16~18% for marina-exclusive facility (mFA), 47~49% for commercial facility (cFA), 27~30% for public space (pFA) and 5~8% for management space (emFA). With this composition as a basis, space program estimation of a Korean marina club can be done through the process of estimating in order the marina-exclusive facility area, the floor area by each space and the total floor area, the first floor area, the deck area and the pontoon area. Since the space program established in this study can be utilized as a tool for designing a Korean marina club, it is expected to be helpful in designing marina clubs in the future.

• 한국표면공학회지
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• 제52권6호
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• pp.364-370
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• 2019

Fe-Mn-Si-Ni-Cr-TiC alloys have a shape memory property, recovering initial shape by heating. With an aim to improve a durability and stability of building and infrastructure, this Fe-based shape memory alloy (FSMA) can be employed to reinforce concrete structure with creation of compressive residual stress. In this work, corrosion resistance of FSMA was compared with general rebar and S400 carbon steel to evaluate the stability in concrete environment. Potentiodynamic polarization test in de-ionized water, tap-water and 3.5 wt.% NaCl solution with variations of pH was used to compare the corrosion resistance. FSMA shows better corrosion resistance than rebar and S400 in tested solutions. However, Cl-containing solution is critical to significantly reduce the corrosion resistance of FSMA. Therefore, though FSMA can be a promising candidate to replace the rebar and S400 for the reinforcement of concrete structure, serious cautions are required in marine environments.