• 한국기계기술학회지
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• 제13권4호
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• pp.131-136
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• 2011

In commercial vehicle, sub-frame which equipped in main frame supporting dump deck and oil tanker. This is the main structure for all equipment which including joint function. Sub-frame is made by welding process, this susceptible to deform and crack by its longitudinal size. Also various kind of sub-frame make it difficult to standardization in manufacturing process and exclusive jig is not adapted yet. Frame size is over 6~8m and weight is more than 300kg this make re-work more difficult. If manufacturing company made precise sub-frame, this is not only convenient for customers but also save the company money by reducing the working time. In this study manufacture the sub-frame be suitable for its main function and develop exclusive welding jig for obtain checking fixture function as well.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권3호
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• pp.507-528
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• 2014

In the ship and offshore structure design, age-related problems such as corrosion damage, local denting, and fatigue damage are important factors to be considered in building a reliable structure as they have a significant influence on the residual structural capacity. In shipping, corrosion addition methods are widely adopted in structural design to prevent structural capacity degradation. The present study focuses on the historical trend of corrosion addition rules for ship structural design and investigates their effects on the ultimate strength performance such as hull girder and stiffened panel of double hull oil tankers. Three types of rules based on corrosion addition models, namely historic corrosion rules (pre-CSR), Common Structural Rules (CSR), and harmonised Common Structural Rules (CSR-H) are considered and compared with two other corrosion models namely UGS model, suggested by the Union of Greek Shipowners (UGS), and Time-Dependent Corrosion Wastage Model (TDCWM). To identify the general trend in the effects of corrosion damage on the ultimate longitudinal strength performance, the corrosion addition rules are applied to four representative sizes of double hull oil tankers namely Panamax, Aframax, Suezmax, and VLCC. The results are helpful in understanding the trend of corrosion additions for tanker structures.

• Journal of Advanced Marine Engineering and Technology
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• 제20권3호
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• pp.19-28
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• 1996

In Asia countries the productions of ship building and marine engines have been increasing, specially Japanese marine industries have worked hard after 1960s and Korean ones after 1980s. Recently the other countries, as Taiwan and China, have been working so that these hour Asian countries are occuping the high level of shared ratio of productions for gross tonnages and horse powers, which are 74 and 64[%] of the world ones ($8.6\times10$+6[GT], $8.6\times10$+6[PS]) in 1994. Korean industries had the highest shared ratio of production of tanker vessel and 2 stroke diesel engine as 45[%]($2.2\times10$+6[GT]) and 37[%]($1.0\times10$+6[PS]) which were more than those of Japan as 34 and 16[%] in 1989 respectively. Some marine databases and their network links among Asian countries are proposed due to the posibility of collection and analyses with their own specifications by the marine industries and operators as well as Japanese ship reliability investigation works(SRIW) like SRIC in Japan. During 1966 and 1996 16 times of SRIW in Japan have been carried out by ship reliability investigation group(SRIG) in Japan. There have been collected and evaluated a great number of field data of failures and maintenances($700\times10$+3[occ], $1.6\times10$+6[MH}) during running hours($13.4\times10$+6[Hrs]), from which many kinds of evaluation indices could be gotten as the three indices of occurring rate$\lambda$(52.2[occ/1000Hrs]), average man-hour mh(2.29[MH/occ]) and manning index MI(119[MH/1000Hrs]). An estimation example having the three indices$\lambda$, mh and MI were shown by the SRIC 1990 Data Base in Japan for the two kinds of fuel oil suppling subsystems which are dual fuel oil one(DFOS) and mono fuel oil one(MFOS). Three indices MI, and mh for DFOS and MFOS results in 7.16 and 5.20[MH/1000Hrs], 2.63 and 2.06[occ/1000 Hrs]. Therefore the more simple subsystem MFOS can save approximately 30[%] of maintenance load. Finlly an utilization methods are shown for the SRIC in Japan by means of computer system and worlwide internet links.

• 한국항해항만학회지
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• 제40권6호
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• pp.391-400
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• 2016

최근 우리나라 연근해에서 발생한 몇 건의 대형 해양사고에서, 신속하고 체계적인 초기대응이 사고 전개양상과 사고결과에 얼마나 큰 영향을 미치는지를 확인하였다. 또한, 이를 통해 다양한 해양사고 상황에 대한 정확한 정보와 전개될 수 있는 시나리오, 적용 가능한 사고대응 방법들에 대한 정보를 신속하게 확보하는 것이 해양사고 초기대응을 위하여 무엇보다 중요함을 알 수 있었다. 이러한 현실적인 문제를 해결하기 위한 일환으로, 본 연구에서는, '위험도기반 초기대응 지원 시스템'의 개념을 제시하고, 해양사고 이후 전개 가능한 모든 시나리오와 적용 가능한 사고대응 방법들을 식별하기 위하여 사건전개 시나리오 식별 브레인스토밍 기법을 제안하였으며, 식별된 사고대응 방법들의 적용으로 인한 피해저감 효과 등을 정량화하기 위하여 사건수목분석 (Event Tree Analysis: ETA) 기법을 활용한 사건전개수목을 제안하였다. 그리고 각각의 사고대응 방법에 대한 상세분석을 위해서는 PERT/CPM의 사용을 제안하였다. 또한, 상기 제시한 위험도기반 초기대응 지원시스템의 구성 체계를 설명하기 위하여, 유조선 좌초사고에 대한 사고대응 작업을 예로 간략한 위험도분석 작업을 수행하였다.

• 한국항해항만학회지
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• 제35권10호
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• pp.823-827
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• 2011

2016년 7월부터 강제 적용 예정인 목표기반 선박건조 기준(GBS)의 설계단계의 기능요건 중 잔류강도 평가 부분은 현재의 유조선설계, 건조 규칙인 공통구조규칙에는 아직 포함되어 있지 않은 실정이다. 기능요건에 포함된 잔류강도 부분은 충돌이나 좌초와 같은 해상사고시 발생가능한 선체손상을 고려하여 강도측면의 제한조건을 규정함으로써 사고시에도 일정부분 선박의 안전을 확보하려는 것이다. GBS에서 주로 다루고 있는 위험도에 근거하여 잔류강도를 평가하기 위해서는 다양한 손상에 대한 광범위한 평가 작업이 필요하다. 이때, 매번 비선형 유한요소해석을 수행하기보다 선체구조를 보강판 요소의 집합으로 보는 간이화된 강도 해석법의 하나인 Smith법이 유용할 것이다. 본 연구에서는 좌초사고로 인해 선저가 손상된 경우를 대상으로 Smith법을 적용하여 최종강도 평가를 수행하였으며, 3개의 화물창 구역을 모델링하여 수행한 비선형 구조해석 결과와의 비교를 통해 Smith법을 적용한 결과의 정도를 확인하였다.

• 해양환경안전학회지
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• 제19권2호
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• pp.129-137
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• 2013

해양기름오염방지를 위한 정량적 기초자료를 얻기 위하여 최근 20년간(1993년-2012년) 국내 및 세계의 해양에서 발생한 기름유출사고에 관한 통계자료를 수집하고 분석하였다. 최근 20년간 국내 연안에서 발생한 기름오염사고건수는 총계 6,608건으로 평균 약 330건/년이었고 기름유출량은 총계 57,328 kL로 평균 약 2,866 kL/년이었다. 국내에서 유조선의 대량기름유출사고로 인하여 연간유출량이 1993년에 15,388 kL, 1995년에 15,773 kL, 1997년에 3,428 kL, 2007년에 13,008 kL로 크게 증가하였다. 최근 20년간(1993년-2012년) 세계의 사고건수는, 기름유출량이 8 kL(7톤) 이상인 경우, 총계 420건으로 평균 21건/년이었고, 세계의 기름유출량은 총계 약 800,000 kL(704,000톤)로 평균 약 40,000 kL(35,200톤)/년이었다. 특히 2012년에는 800 kL(700톤)을 초과하는 기름유출사고가 발생하지 않았다. 그러나 기름유출량이 8 kL(7톤) 이상인 사고에서 유조선의 대량기름유출사고로 인하여 세계의 연간기름유출량은 1993년에 약 159,000 kL(140,000톤), 1994년에 약 147,600 kL(130,000톤), 1996년에 약 90,900 kL(80,000톤), 1997년에 약 81,800 kL(72,000톤), 2002년에 약 76,100 kL(67,000톤)로 크게 증가하였다. 국내와 세계를 비교하면, 국내적으로나 세계적으로 공히 20년간 연간사고건수와 연간기름유출량과의 상관관계는 명확하지 않았으며 사고건수와 유출량이 모두 연도별로 변동 폭이 크지만 해가 거듭될수록 감소하는 경향을 보였다. 2008년부터 세계의 사고건수와 유출량은 모두 크게 감소하였고, 특히 2012년에는 800 kL(700톤) 이상의 기름유출사고는 발생하지 않았다.

• Journal of Advanced Marine Engineering and Technology
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• 제40권3호
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• pp.191-197
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• 2016

선박이 고출력화, 대형화 됨에 따라 추진축의 강성은 증가한 반면에 선체는 고장력 후판을 사용하므로 이전의 선체보다 훨씬 더 쉽게 변형되는 실정이다. 흘수변화에 따른 선체변형은 축계를 구성하는 각각의 베어링 옵셋 및 반력에 연쇄적인 영향을 미치게 된다. 이는 기존의 선박보다 더욱 정교한 축계정렬이 요구됨을 의미한다. 본 연구에서는 최근 친환경 고효율 선박으로 등장한 5만 DWT급 석유화학제품운반선을 대상으로 선박의 흘수 변화에 따른 선미부 구조해석을 실시하고 구조해석으로부터 얻어진 축계의 상대변위를 이용하여 축계정렬 해석을 수행하였다. 구조해석은 선박의 통상 운항조건에서 최대 흘수 변화를 고려한 2개 조건에서 수행하였다. 이를 바탕으로 선체변형에 따른 베어링 옵셋 변화가 축계정렬에 미치는 영향을 검토하였다.

• 대한조선학회논문집
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• 제53권4호
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• pp.336-342
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• 2016

H-CSR(Harmonized Common Structural Rules) integrating CSR-BC(Common Structural Rules for Bulk Carriers) and CSR-OT(Common Structural Rules for Double Hull Oil Tankers) came into effect in July of 2015, so that bulk carrier and double hull oil tanker should comply with this rules. So far, several studies for trend analysis of requirements of structure scantling based on H-CSR have been carried out briskly. However, those studies are rare to apply H-CSR in actual structural design of ships, especially bulk carriers. In this study, an automated system for compartment arrangement is used to search the design case that minimizes still water bending moment(S.W.B.M) in 38k bulk carrier designed by Far East Ship Design & Engineering Co. Ltd. Also, various structural design cases are considered by changing arrangement of structural members to reduce ship weight. The SeaTrust-Hullscan software developed by Korean Register is used to perform structural design of ships based on mother ship and proper design cases are selected by user. The DSA(Direct Strength Analysis) is performed to evaluate structural safety for the yielding and buckling analysis by using MSC Nastran software. The effect of weight reduction is verified by comparison of ship weight between mother ship and the selected design cases.

• 대한조선학회논문집
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• 제50권3호
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• pp.145-152
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• 2013

Recently, with oil price jumping and environmental issues, Green ship is paid deep attention to by ship owner, operator, builder, class and government. Fuel efficiency and reduction of $CO_2$ emissions are expected to have a strong influence on the design and operation of merchant ships. Many ship owners and operators are seeking the more economic method by the best operating route and the application of reliable and effective energy saving devices. With the Energy Efficiency Design Index (EEDI) in 2013 attention will more than ever be focused at achieving maximum fuel economy in the hydrodynamic design of hull forms, their appendages and propellers. IMO requirements for $CO_2$ emission for ships will now be implemented for vessels ordered from 1st January 2013. So far, a lot of new idea and patents have been proposed, tested, claimed and applied for various kinds of ship type. This paper shows numerical and experimental work related to a study on a energy saving devices particularly for fuller ship such as merchant vessel of Tanker and Bulker. From the bare hull wake measurements, typical upper/lower asymmetry of hull wake at the propeller disk was found. The pre-swirl duct have been designed and reviewed to recover the loss of propeller running in that condition. The general function of the pre-swirl duct was set to work against this asymmetry of wake and generate pre-swirled flow into the propeller against the propeller rotating direction.

• Structural Engineering and Mechanics
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• 제52권3호
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• pp.613-632
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• 2014

In the early design stage of ships, the two most important structural analyses are performed to identify the structural capacity and safety. The first step is called global strength analysis (longitudinal strength analysis or hull girder strength analysis) and the second step is local buckling analysis (stiffened panel strength analysis). This paper deals with the ultimate strength performance of Arctic Sea Route-going commercial ships considering the effect of low temperature. In this study, two types of structural analyses are performed in Arctic sea conditions. Three types of ship namely oil tanker, bulk carrier and container ship with four different sizes (in total 12 vessels) are tested in four low temperatures (-20, -40, -60 and $-800^{\circ}C$), which are based on the Arctic environment and room temperature ($20^{\circ}C$). The ultimate strength performance is analysed with ALPS/HULL progressive hull collapse analysis code for ship hulls, then ALPS/ULSAP supersize finite element method for stiffened panels. The obtained results are summarised in terms of temperature, vessel type, vessel size, loading type and other effects. The important insights and outcomes are documented.