• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.28-35
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• 2005

It is now well recognized that the ultimate limit state approach is a much better basis for design and strength assessment of ships and offshore structures since it is difficult to determine the realistic margin of safety using the traditional allowable working stress approach on the basis of linear elastic method solutions together with buckling strengthchecks adjusted by a simple plasticity correction. This paper outlines ALPS theory for ultimate limit state assessment of ship structures. ALPS is a computer software which stands for nonlinear Analysis of Large Plated Structures. Application examples of ALPS program to ultimate limit state assessment of plates, stiffened panels and ship hull girders are presented. A benchmark study is made by a comparison with the ALPS solutions with other methods including class rule formulae, nonlinear finite element methods and experimental results. Future trends on ultimate limit state assessment of ship structures are addresse[1]

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.283-287
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• 2004

Arc welding is sometimes used to repair damaged cast iron parts in diesel engine for driving a ship. In this case cola arc welding. is good for. saving the time and results in good repairing. But if some difference in hardness on welding zones made with AWS E Ni-CI and NiFe-CI. happen, repaired parts would be cracked in a short. In order to overcome this default, the study is performed on varying preheating temperature of welding parts, selecting welding rod and welding work way. The result will be used on ship's repair working shop.

• 한국해양공학회지
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• 제20권2호
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• pp.41-45
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• 2006

Arc welding is sometimes used to repair damaged cast iron parts in diesel engine for driving n ship. In this case cold arc welding is good for saving the time and results in good repairing. But if some difference in hardness on welding zones made with AWS E Ni-CI and NiFe-CI happen, repaired parts would be cracked in a short. In order to overcome this default, the study is performed on varying preheating temperature of welding parts, selecting welding rod and welding work way. The result will be used on ship's working shop.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2008년도 춘계학술발표회
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• pp.101-104
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• 2008

1978년도부터 2007년도까지 30년간 해양경찰청 소속 해양환경감시원이 선박에 직전 승선하여 해양오염방지설비의 정상가동 여부 및 각종 오염물질 기록부의 비치 기록 관리여부와 폐유 및 폐기물 처리 실적을 확인하고 선외 배출여부 등을 점검하여 오던 해양환경관리법 제 115조에 좌한 사후적 해양오염 점검 성격의 선박출입검사 제도를 선박이 스스로 해양오염을 관리 점검하고 선박 종사자의 불편과 경제적 활동에 대한 부담을 덜어 주기 위해 해양오염을 사전에 예방할 수 있는 선박자율점검 제도에 대하여 제시하였다.

• 한국정보통신학회논문지
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• 제19권8호
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• pp.1831-1838
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• 2015

본 논문은 전력선 기반 무배선통신시스템을 이용하여 선박에 통신네트워크를 구축하는 방안을 제시한다. 이를 위하여 전력선과 데이터통신 기기의 연결을 위한 유도성 결합장치와 복합통신장치를 개발한다. 실제 운항되는 선박을 대상으로 시험한 결과, 구현된 무배선통신시스템은 최장 200 m 거리에서 25.8 Mbps 이상의 전송속도를 제공하고, 통신 성공률은 100%인 것으로 측정되었다. 따라서 제시된 시스템은 전송채널의 추가 설치 없이도 선박에 통신네트워크를 구축할 수 있는 유용한 대안인 것으로 판단된다. 또한 설치가 용이하고 데이터통신을 위한 다양한 인터페이스를 지원하므로 미래 디지털 선박에 실시간 모니터링 시스템을 도입하는 경우 매우 효과적일 것으로 기대된다.

• 수산해양기술연구
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• 제48권1호
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• pp.91-98
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• 2012

This study is aimed to utilize a basic data for setting up an allowable air noise with IMO standard in accommodation and working areas of 24m longer fishing vessels. The air noise in accommodation and working areas of 300 tons class squid-jigger were evaluated and the levels were compared to the allowable levels of IMO. The results indicated that the maximum range of noise levels was estimated to be between 54.8dB (A) and 83.2dB, and the correlation between the distance from the main engine to measuring point and the maximum noise level of each point was shown to be y=-13.8log (r)+92.91 ($r^2=0.821$). In addition, except the case of making an accommodation area near to the engine room in 24m longer jigging vessels, it was evaluated that the accommodation noise regulation of 1,600 tons international voyage vessels with 60dB (A) or an improved noise level with 65dB (A) could be properly applied.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.260-265
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• 2004

The materials of ship screw propeller are commonly the manganese bronze. The seawater corrosion and cavitation of the screw propeller reduce tire propulsive performance of ship. In screw manufactory, tire corrosion rust of tire screw propeller is removed by a hand grinding. The grinding work makes the dust of the heavy metals from the manganese bronze. The dust makes indoor working environment poor. A friendly-environmental and automatic corrosion removing apparatus was developed for the improvement of screw processing and working environment. The corrosion rust of a screw propeller was remarkably removed by using apparatus. And the screw surface roughness was improved by a blasting effect of the apparatus performance test. Anode polarization curves on jour processing conditions, that is to say, grinding, blasting, wire-brushing, fine sand papering, were confirmed by a potentiostat. Especially, two kinds of medias, alumina and emery, were used in the blasting processing. Then, investigated tire cavitation erosion of specimen. This result proved that tire blasting work has considerably improved the corrosion resistance of a screw propeller.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 춘계학술대회 및 창립 30주년 심포지엄(논문집)
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• pp.185-190
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• 2006

항주파에 의해 해안침식, 호안 결괴, 하역곤란 및 어선 등을 포함한 소형선박의 동요가 발생하며, 심지어 최근에는 수상오토바이, 모터보트 및 여객선의 고속주행은 해수욕장의 수영객 및 낚시꾼 등 어로작업중인 어민에게 위협이 되고 있다. 특히, 천해역에서 발생한 항주파는 심해역에서 발생한 항주파보다 연안시설 또는 작업인원의 안전에 더 큰 영향을 미칠 수 있으며, 파고는 천해역에서 발생하여 극천해역으로 진행하는 경우, 천해역 파고의 1.8배정도로 커진다. 또한 극천해역에 약간의 흐름이 존재하여도 파는 진행하지 못한다.

• 대한조선학회논문집
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• 제59권5호
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• pp.314-322
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• 2022

During the shipbuilding process, many blocks are moved between shipyard workshops by block carrying vehicles called a transporter. Because block logistics management is one of the essential factors in enhancing productivity, it is necessary to manage block information with the transporter that moves it. Currently, because a large amount of data per day are collected from sensors attached to blocks and transporters via IoT infrastructure installed in shipyards, automated methods are needed to analyze them. Therefore, in this study, we developed an algorithm that can automatically match the transporter and the working block based on the GPS sensor data. By comparing the distance between the transporter and the blocks calculated from the Haversine formula, the block is found which is moved by the transporter. In this process, since the time of the measured data of moving objects is different, the time standard for calculating the distance must be determined. The developed algorithm was verified using actual data provided by the shipyard, and the correct result was confirmed with the distance based on the moving time of the transporter.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권5호
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• pp.423-433
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• 2016

In this paper, we consider the cybersecurity issue of ship information system (SIS) from a new perspective which is called opacity. For a SIS, its confidential information (named as "secret") may be leaked through the working behaviors of each Distributed Control Unit (DCU) from an outside observer called an "intruder" which is able to determine ship's mission state by detecting the source of each data flow from the corresponding DCUs in SIS. Therefore we proposed a dual layer mechanism to enforce opacity by activating non-essential DCU during secret mission. This mechanism is calculated by two types of insertion functions: Safety-assured insertion function ($f_{IS}$) and Admissibility-assured insertion function ($f_{IA}$). Due to different objectives, $f_{IS}$ is designed to confuse intruder by constructing a non-secret behaviors from a unsafe one, and the division of $f_{IA}$ is to polish the modified output behaviors back to normal. We define the property of "$I_2$-Enforceability" that dual layer insertion functions has the ability to enforce opacity. By a given mission map of SIS and the marked secret missions, we propose an algorithm to select $f_{IS}$ and compute its matchable $f_{IA}$ and then the DCUs which should be activated to release non-essential data flow in each step is calculable.