• 대한조선학회논문집
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• 제60권1호
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• pp.48-56
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• 2023

This paper implements many-to-many communication between users and develops a multi-functional smart helmet for worker protection and environmental safety in the shipbuilding and shipping industry. First, the communication situation is recorded in the field to perform signal processing for noise that interferes with communication. Then, it deals with the contents of developing smart helmets, data acquisition, algorithms, and simulations. The simulation results analyzed by applying the adaptive algorithm are shown, and their usefulness is confirmed. In conclusion, looking at the optimization process for the convergence factor of the Least Mean Square and Filtered-x Least Mean Square Adaptation Algorithm was possible. It is thought that it has laid the foundation for implementing many-to-many communication, the function of smart helmets that reduces or removes various noises at the shipyard in the future.

• Ocean Systems Engineering
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• 제13권1호
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• pp.79-95
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• 2023

An onshore dismantling yard is an important part in the supply chain of the offshore oil and gas decommissioning industry. However, despite having more than 500 offshore structures to be decommissioned in the Southeast Asia region, there are a very limited number of well-equipped dismantling yards to fully execute the onshore dismantling. Recent investigations discovered that shipbuilding and offshore structure fabrication yards are still potential options for upgrades to include dismantling. Despite the huge potential opportunities from upgrading to dismantling, research studies on this area are relatively scarce, and most past studies mainly focused on the North Sea region. To date, the potential opportunities of Southeast Asia and Malaysia yards to develop onshore dismantling capability are still unclear. The aim of this study is to identify the criteria to develop a technical preparedness checklist to evaluate an onshore dismantling yard; consequently, this will assist with assessing and bridging the gaps and identify the opportunity of developing an onshore dismantling yard in Southeast Asia region. Requirements for onshore dismantling and related rules and regulations have been investigated and summarized in the form of checklist. Findings from this study can help local oil and gas operators to pursue more local solutions and resilient supply chain performance.

• 무역학회지
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• 제45권4호
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• pp.65-81
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• 2020

Under New Climate Regime, countries are trying to enhance environmental regulations to meet international standards. This study is designed to examine the relationship between the relative level of environmental regulation of the importing countries and the export performance at the industrial level. Panel data from 2009 to 2018 was established for 12 top export industries and empirical analysis was conducted. For the analysis method, panel OLS, Hausman-Taylor, and panel GLS were used based on the results of the Hausman verification. The dependent variable is the export performance of each industry. As the independent variables, the relative level of environmental regulation, GDP per capita of the importing country, exchange rate, FTA agreement, and physical distance from the importing country were used. Results show that the relative level of environmental regulation has a negative effect on export performance of semiconductors, displays, special machines, general machines, electric appliances, and home appliances. On the other hand, there are no relationship between the relative level of environmental regulation of the importing country and export performance of automobile, petroleum refining, petrochemical, shipbuilding, and communication equipment industries.

• 한국기계가공학회지
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• 제19권9호
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• pp.100-106
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• 2020

This study analyzes the residual stress of AISI 1536V for an engine shaft of the shipbuilding industry and AISI A387 for a reactor shell of the chemical refining industry by the hole drilling method with a strain gauge rosette, which transforms fine mechanical changes into electrical signals. Tensile residual stress is generated in the forging and heat treatment process because specimens are affected by thermal stress and metal transformation stress. In the heat treatment process, the residual stress of AISI A387 is almost 170% the yield strength at 402 MPa. Since during the machining process, variable physical loads are applied to the material, compressive residual stress is generated. Under the same condition, the mechanical properties greatly affect the residual stress during the machining process. After the stress-relieving heat treatment process, the residual stress of AISI A387 is reduced below the yield strength at 182 MPa. Therefore, it is necessary to control the temperature, avoid rapid heat change, and select machining conditions depending on the mechanical properties of materials during manufacturing processes. In addition, to sufficiently reduce the residual stress, it is necessary to study the optimum condition of the stress-relieving heat treatment process for each material.

• 한국해양공학회지
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• 제25권6호
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• pp.66-71
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• 2011

Recently, the production of shipbuilding and offshore plant industries, with a trend toward large structures, has led to an increased use of high strength ultra-thick plates. The use of ultra-thick plates increases the welding tasks, and the welding process generates distortion and residual stress in the weldment because of the rapid heating and cooling. Welding distortion and residual stress in the welded structure resulte in many troubles such as deformation and life deterioration. In particular, the welding residual stress has an important effect on welding deformation, fatigue, buckling strength, brittleness, etc. The purpose of this study was to evaluate the residual stress at a multi-pass weldment using an experimental method for EH36 high-tension steel. In this experimental method, AIS3000 was used to measure the residual stress of a welded part, HAZ, and base metal; EPMA and XRD were used to study the material properties.

• 한국항만경제학회지
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• 제29권4호
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• pp.97-117
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• 2013

한국은 세계 제 1위의 조선산업 국가이면서도 국내 선박금융의 공급은 한계를 보여 왔다. 이 때문에 선박금융 확대 요구가 증대되었으며, 이에 대처하기 위해 정치권을 중심으로 선박금융지원정책에 대한 논의가 활발히 진행되어 왔다. 한편 부산시는 정부로부터 지정받은 금융중심지의 특화금융 분야 중 하나로 선박금융을 꼽고, 선박금융활성화에 많은 관심과 노력을 기울이고 있다. 본 연구는 이러한 점을 감안하여 선박금융지원정책에 대한 부산시의 선호도를 조사함에 목적이 있다. 연구를 위해 AHP(Analytic Hierarchy Process)방식이 활용되었고, 인터뷰와 설문조사에는 부산시의 해운정책담당 공무원, 금융기관 종사자, 경제연구소 직원 등이 참여하였다. 정책대안으로는 (1) 선박금융공사 설립 (2) 해운보증기금 설치 (3) Tonnage Bank 설립 (4) 기존 국책금융기관의 선박금융업무 통폐합 (5) 기존 기관의 관련부서 부산으로의 이전 등이 제시되었다. 분석결과 부산시는 이 중 선박금융공사 설립을 가장 선호하는 안으로 꼽고 있는데 이는 정부나 선박금융시장에서의 선호도와는 차이가 큰 결과이다.

• 해양환경안전학회지
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• 제21권6호
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• pp.712-720
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• 2015

무역장벽의 일종인 카보타지는 자국내 내항해운업을 보호하여 왔다. 자국에서 건조한 선박으로 자국 선원이 승선하여 자국의 화물을 운송한다는 카보타지를 운영한 미국은 조선산업과 해운 연관산업이 유지되어 왔다. 그리고 대부분의 국가는 경제적 이유와 유사시 대처라는 이유 때문에 자국적 선박을 통해 저탄소 운송인 내항해운을 담당하는 카보타지를 운영하고 있다. 카보타지를 유지하기 위해서는 선원의 안정적인 공급이 필요하다. 선원의 안정적인 공급은 선원양성 교육기관의 안정적인 운영에 달려있기 때문에 법률적인 검토가 필요하다. 본 연구에서는 내항해운의 안정적 선원공급을 통한 카보타지 확립에 관련하여 우리나라 내항해운의 문제점과 선원 실태를 분석하였다. 분석결과 미국과 같은 선원양성에 관련한 법률을 제정하거나 정비할 필요가 있음을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제40권9호
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• pp.774-779
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• 2016

본 연구에서는 선박의 곡 외판 구조에 TMCP 강재의 사용 범위 확대 가능성을 연구하고자 노말라이징강 및 TMCP 강 DH32 재질 강재에 선상가열 후 기계적 물성 시험을 실시하여 DNV 선급 및 IACS 규정의 품질 요구 기준에 적합한지 연구하였다. TMCP강재 인장시험에서 요구기준 YS = 315 MPa 대비 385 Mpa로서 약 18% 높게 나타났고, TS = 440 ~ 570 MPa 기준 대비 525 MPa로 요구 기준에 적합하였다. 샤르피 V-노치 $-20^{\circ}C$ 충격시험에서도 요구 기준에 적합하였으며 경도시험에서 평균 T : 216, L : 275로서 규정인 Hv10 = 130 ~320 범위에 만족 하였다.

• 수산해양교육연구
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• 제24권1호
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• pp.34-43
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• 2012

In order to establish order in fishing industry by cracking down on illegal fishing vessels effectively, it is an essential requirement to identify marking such as the name of fishing vessel and a port of register more easily. Accordingly, it is quite natural that markings on fishing vessels should be marked clearly in an appropriate size on an appropriate site in order for them to be distinguished on the air such as from planes as well as on the sea. Actually, when examining marks such as the name of a vessel which are operating in the country, marks of most fishing vessels are too small as they cannot be distinguished with the naked eye even very closely. There is no coastal fishing vessel which marks the name of fishing vessel on the upper part in order to distinguish it from planes. Fishing vessel law generally which regulates the basic laws about shipbuilding regulates marks on fishing vessel, and fisheries law only regulates sign boards of fishing vessels. Problems and improvement of the marking system on fishing vessels suggested by this paper are as follows. First, in order to contribute to establish order in fishing industry, it would be desirable to tighten standards in fisheries law besides the fishing vessel law. Second, it is difficult to distinguish marks such as the name of a vessel as relevant laws allow fishers to make such marks too small. It is necessary to set the standard for marks larger than those regulated by the international treaty. Third, the relevant laws do not regulate a letter form of marks. Therefore, it becomes a factor to make small marks hard to be distinguished more. It is necessary to decide a clear letter form. Fourth, there is insufficient detailed international standards about the marking system. It is necessary to regulate a detailed standard.

• 수산해양기술연구
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• 제55권2호
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• pp.162-171
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• 2019

This study is aimed to develop an improved shellfish dredge vessel considering the increase of the fishing safety and welfare of fishermen in Jeonnam province. We visited five fishing village societies in Korea, and conducted field surveys and survey questions to investigate the current status. In order to solve the problems presented by the investigation, a general arrangement of the improvement vessel was written and adopted after meeting between the fishermen and research team, and calculated the initial stability in five loading conditions by using the Napa program. As a result of field surveys and survey questions, the existing vessel have buoyant materials under the bow and the warp pass through the wheel-house. In addition, most fishing equipment and nets are concentrated on a narrow stern, making it difficult to work efficiently. According to the survey, fishermen also responded that operation of casting and hauling is very inconvenient. The fishing equipment of the improvement vessel was rearranged, the size of the wheel-house and the crew room was increased, and we secured a basic welfare space. As a result of the initial stability test, the stability criteria of the fishing vessel were satisfied in all loading condition.