• 해양환경안전학회지
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• 제28권4호
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• pp.657-666
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• 2022

국제해사기구(IMO)는 국제해운 분야의 온실가스(Green House Gas, GHG) 감축을 위하여 각국의 기술 개발 및 에너지 효율성 제고에 관한 정책 시행을 적극적으로 권장하고 있다. 이러한 IMO의 환경규제와 관련된 정책들은 해운 분야 전반에 큰 영향을 미치고 있으며, 선주들에게도 막대한 부담으로 작용하고 있다. 선박에서 발생하는 GHG 배출을 억제하기 위한 가장 합리적인 방안은 탄소제로배출(Zero Emission) 선박의 개발로 귀결된다. 즉 친환경 연료로 추진하는 연료전지선박(Fuel Cell Ship, FCS)의 개발이 IMO의 규제를 벗어날 수 있는 대안인 것이다. 아시아, 북미, 유럽 등의 각국에서는 독자적으로 PEMFC를 개발 및 생산하여 국제공인등록 기관으로부터 형식승인인증을 획득함으로써 국제표준화의 선점을 추구하고 있다. 현재 다양한 연료전지(Fuel Cell, FC) 중에서 선박용으로 권장하는 것은 크게 고분자전해질 연료전지(PEMFC), 용융 탄산염 연료전지(MCFC) 및 고체산화물형 연료전지(SOFC) 등의 세종류가 있다. 본 연구에서는 글로벌 FC 시장에서 지속적인 성장이 예상되는 PEMFC를 대상으로 하여 국내외 개발 동향, 제조업체별 규격, 성능 및 선박에 적용한 실증적 사례를 분석하였다. 그리고 PEMFC를 선박에 적용할 경우, 고려해야 할 사항과 개발 방향에 관하여 제안하고자 하였다.

• 해양환경안전학회지
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• 제29권6호
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• pp.681-687
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• 2023

최적 운항자세 선정 기술이란 주어진 운항 배수량과 운항 선속에서 최소의 저항을 가지는 즉, 최적의 연료 소비 효율을 가지는 초기 선수흘수와 선미흘수를 제시하는 것이다. 본 논문의 주 목적은 대상선박의 유효동력 데이터를 기반으로 주어진 운항조건에서 최대의 에너지효율을 가지는 최적의 운항자세를 선정하는 프로그램 개발하는 것이다. 본 프로그램은 인공지능 기법에 의한 파이썬 기반 GUI(Graphical User Interface)로 작성되어 선주가 쉽게 사용할 수 있도록 하였다. 그 과정에 있어 대상 선박 소개, 전산유체역학(CFD)을 통한 유효동력 데이터 수집, 심층학습을 사용한 유효동력 모델 학습 방법 그리고 심층신경망(DNN) 모델을 응용한 최적 운항자세 제시 프로그램을 구체적으로 설명하였다. 선박은 운항 별로 화물을 싣고 내리게 되고, 이에 화물 적재량이 변화되고 배수량이 변경된다. 선주는 배수량 별 예상 선속에 따라 최소저항을 가지는 즉, 최대의 에너지효율을 가지는 최적의 운항자세를 알고자 한다. 개발된 GUI는 해당선박의 태블릿 PC와 앱에 설치하여 최적 운항자세 선정에 활용 가능하다.

• Journal of Welding and Joining
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• 제34권1호
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• pp.47-53
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• 2016

WPS/PQR is the essential documents for shipbuilding welding. WPS is the document containing the information related to welding procedure and PQR is the record of approval for welding procedure. Both documents should be approved by the ship owners and the classification societies. It is very important to manage these documents because the welding procedure using these documents could not be carried out before they are approved. Database is an useful tool to manage these documents. It can manage a number of documents and show the processing status of WPS/PQR documents. In this study, all documents related to WPS/PQR documents were investigated and analyzed in the viewpoint of DB. An appropriate DB system was designed for WPS/PQR and the related documents on the basis of CBD methodology. The DB system could make WPS/PQR documents easily and shortly. The grasp of the processing status of WPS/ PQR could help the good management of fabrication schedule in shipbuilding.

• Ocean Systems Engineering
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• 제1권1호
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• pp.31-57
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• 2011

Impact pressure due to sloshing is of great concern for the ship owners, designers and builders of the LNG carriers regarding the safety of LNG containment system and hull structure. Sloshing of LNG in partially filled tank has been an active area of research with numerous experimental and numerical investigations over the past decade. In order to accurately predict the sloshing impact load, a new numerical method was developed for accurate resolution of violent sloshing flow inside a three-dimensional LNG tank including wave breaking, jet formation, gas entrapping and liquid-gas interaction. The sloshing flow inside a membrane-type LNG tank is simulated numerically using the Finite-Analytic Navier-Stokes (FANS) method. The governing equations for two-phase air and water flows are formulated in curvilinear coordinate system and discretized using the finite-analytic method on a non-staggered grid. Simulations were performed for LNG tank in transverse and longitudinal motions including horizontal, vertical, and rotational motions. The predicted impact pressures were compared with the corresponding experimental data. The validation results clearly illustrate the capability of the present two-phase FANS method for accurate prediction of impact pressure in sloshing LNG tank including violent free surface motion, three-dimensional instability and air trapping effects.

• 한국항해항만학회지
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• 제41권5호
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• pp.251-258
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• 2017

Shortage of trained seafarers is an issue, which many ship-owners are facing and, according to recent studies, the shortfall of both officers and rating will worsen in the next few years. The key role of seafarers is of fundamental importance in international trade, as they are the ones responsible for safely manning and operating ships. In developing countries, they also perform a strategic aspect in terms of contribution to GDP, mainly by earning foreign currency and increasing national consumption of goods and services. Myanmar is still considered a developing country with an economy, which has only recently started growing steady. It is also one of the major seafarers supplying nations and the contribution, which seafarers have on the national GDP may be particularly significant in comparison to other countries. This study aims at investigating seafarers' impact towards the Myanmar national economy. The paper describes the status of Myanmar seafarers, and the seafarers' current and forecasted impact towards the Myanmar economy through a regression model. The study concludes with recommendations to make Myanmar seafarers more competitive internationally and increase their economic contribution nationally.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권4호
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• pp.491-498
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• 2018

The cost evaluation for voyage route planning in an ice-covered sea is one of the major topics among ship owners. Information of the ice properties, such as ice type, concentration of ice, ice thickness, strength of ice, and speed-power relation under ice conditions are important for determining the optimal route in ice and low operational cost perspective. To determine achievable speed at any designated pack ice condition, a model test of resistance, self-propulsion, and overload test in ice and ice-free water were carried out in a KRISO ice tank and towing tank. The available net thrust for ice and an estimation of the ice resistance under any pack ice condition were also performed by I-RES. The in-house code called 'I-RES', which is an ice resistance estimation tool that applies an empirical formula, was modified for the pack ice module in this study. Careful observations of underwater videos of the ice model test made it possible to understand the physical phenomena of underneath of the hull bottom surface and determine the coverage of buoyancy. The clearing resistance of ice can be calculated by subtracting the buoyance and open water resistance form the pre-sawn ice resistance. The model test results in pack ice were compared with the calculation results to obtain a correlation factor among the pack ice resistance, ice concentration, and ship speed. The resulting correlation factors were applied to the calculation results to determine the pack ice resistance under any pack ice condition. The pack ice resistance under the arbitrary pack ice condition could be estimated because software I-RES could control all the ice properties. The available net thrust in ice, which is the over thrust that overcomes the pack ice resistance, will change the speed of a ship according to the bollard pull test results and thruster characteristics (engine & propulsion combination). The attainable speed at a certain ice concentration of pack ice was determined using the interpolation method. This paper reports a procedure to determine the attainable speed in pack ice and the sample calculation using the Araon vessel was performed to confirm the entire process. A more detailed description of the determination of the attainable speed is described. The attainable speed in 1.0 m, 90% pack ice and 540 kPa strength was 13.3 knots.

• 무역상무연구
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• 제12권
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• pp.377-401
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• 1999

This study is focused on the privity of the contract of carriage of goods by sea, so to speak, privity between B/L holder and carrier by transfer of bill of lading, privity by attornment to delivery order and conflict between bills of lading and charterparty terms. Under a CIF contract, possession of the bill of lading is equivalent to possession of the goods, and delivery of the bill of lading to the buyer or to a third party may be effective to pass the property in the goods to such person. The bill of lading is a document of title enabling the holder to obtain credit from banks before the arrival of the goods, for the transfer of the bill of lading can operate as a pledge of the goods themselves. In addition, it is by virtue of the bill of lading that the buyer or his assignee can obtain redress against the carrier for any breach of its terms and of the contract of carriage that it evidences. In other words the bill of lading creates a privity between its holder and the carrier as if the contract was made between them. The use of delivery orders in overseas sales is commen where bulk cargoes are split into more parcels than there are bills of lading, and this practice gives rise to considerable difficulties. For example, where the holder of a bill of lading transferred one of the delivery orders to the buyer who presented it to the carrier and paid the freight of the goods to which the order related, it was held that there was a contract between the buyer and the carrier under which the carrier could be made liable in repect of damage to the goods. The contract was on the same terms as that evidenced by, or contained in, the bill of lading, which was expressly incorporated by reference in the delivery order. If the transferee of the delivery order presents it and claims the goods, he may also be taken to have offered to enter into an implied contract incorporating some of the terms of the contract of carriage ; and he will, on the carrier's acceptance of that offer, not only acquire rights, but also incur liabilities under that contract. Where the terms of the charterparties conflict with those of the bills of lading, it is interpreted as below. First, goods may be shipped in a ship chartered by the shipper directly from the shipowner. In that case any bill of lading issued by the shipowner operates, as between shipowner and charterer, as a mere receipt. But if the bill of lading has been indorsed to a third party, between that third party and carrier, the bill of lading will normally be the contract of carriage. Secondly, goods may be shipped by a seller on a ship chartered by the buyer for taking delivery of the goods under the contract of sale. If the seller takes a bill of lading in his own name and to his own order, the terms of that bill of lading would govern the contractual relations between seller and carrier. Thirdly, a ship may be chartered by her owner to a charterer and then subchartered by the chaterer to a shipper, to whom a bill of lading may later be issued by the shipowner. In such a case, the bill of lading is regarded as evidencing a contract of carriage between the shipowner and cargo-owners.

• 해양환경안전학회지
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• 제24권7호
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• pp.875-888
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• 2018

대한민국 정부는 해양사고 예방 및 해양안전 확보를 위해 지속적으로 법제도를 개선하고 있다. 그럼에도 불구하고 최근 해양사고는 계속적으로 증가하고 있어, 그동안 정부의 해양안전관련 법제도 개선방안 실효성은 미흡했음을 시사하고 있다. 최근 해양사고의 발생현황을 살펴보면, 전체 해양사고 건수 중 총톤수 10톤 미만의 소형어선이 차지하는 비중은 5년('13~'17년)평균의 44.9 %를 차지하고 있다. 이에 따라 본 연구에서는 해양사고 비중이 높은 소형어선의 해양안전 확보방안을 모색하기 위해, 관련 국내외 법제도의 현황과 특징을 조사 및 분석하였다. 그 결과, 국내 소형어선 관련 법제도는 어선과 비어선의 관련법이 통합('97)되고 분법('09)된 이력에 따라 접목교잡(接木交雜)의 현상을 보이고 있으며, 제도의 개선방안은 안전설비의 비치강화라는 단편적인 개선만 이루어 졌다는 문제점이 식별되었다. 또한, 해외 관련 법제도에서는 어선 소유자 및 운항자의 책임강화 및 자율검사제도 도입 등의 특징이 확인되었다. 본 연구에서는 이를 바탕으로 국내 해양안전 확보를 위해 실효성 있는 소형어선 법제도 개선방안을 제시하였다.

• 해양환경안전학회지
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• 제23권4호
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• pp.432-438
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• 2017

본 연구의 주목적은 기존선형을 바탕으로 연료 절감이 가능한 표준화된 개조선형을 개발하는 것이다. 설계 흘수와 설계 선속을 고려하여 대상선박의 선수부 형상을 검토하였다. 실제 운항 상태 별로 대상선박에 대하여 저항성능을 평가하였다. 상용 전산유체역학(CFD) 코드와 수조 모형시험 자료는 유효마력 평가를 위해 사용되었다. 실제 운항 상태를 고려하여 최소저항을 가지는 3가지 개조선형을 제시하였다. 제시된 개조선형은 고객이 선택가능 하다는 점에서 고객 맞춤형 기성품 선형이라고 명하였다. 개조선형 별로 실제 운항 상태에 따라 유효마력을 추정하였다. 가장 낮은 흘수에서 운항할 경우, 기존선형과 비교하여 볼 때 개조3 선형의 저항성능은 저속영역인 16~18노트에서 약 11~16 %로 향상된 결과를 보여 주었다. 중간 흘수인 8.3m에서 운항할 경우, 개조3 선형의 저항성능은 저속영역에서 기존선형보다 약 6~11 %로 향상된 결과를 보여 주었다. 가장 높은 흘수인 9.5m에서 운항할 경우, 모든 선형의 저항성능은 저속영역에서 큰 차이를 보이지 않았다.

• 한국항만경제학회지
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• 제28권4호
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• pp.257-274
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• 2012

글로벌공급사슬간 경쟁이 격화됨에 따라 항만서비스도 항만의 존속과 경쟁력제고를 위한 시장지향적인 가격산정이 크게 필요하다. 협조적 게임이론의 오웬밸류는 선사주체의 시장지향적 항만서비스가격 산정에 활용될 수 있다. 이를 우리나라 광양항의 사례에 적용하여 그 유용성을 확인해보았다. 본 연구결과 부두용 특성함수를 사용하여 선석별 비용배분 문제를 해결하고, Budescu(1993)방법을 통해 안벽사용지수를 구하기 위한 관련요인의 상대적 가중치를 합리적으로 산정하였다. 또한 주요 선사에 대한 사용료 우대방안과 선사간 전략적 제휴에 의한 항만서비스 가격할인방안을 구축하였다. 본 연구를 결과를 활용하여 대형선박을 자주 운항하는 주요 선사에 대한 체계적인 요금할인을 통해 항만서비스요금을 전략적으로 책정 할 수 있을 것이다.