• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.5
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• pp.961-972
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• 2024

As IT and OT systems become integrated into ship operations, the security of propulsion, control, communication, and navigation systems has become increasingly critical. In response, the International Association of Classification Societies (IACS) will enforce cybersecurity requirements starting from July 2024. IACS No. 171 (Recommendations on Incorporating Cyber Risk Management into Safety Management Systems) presents quantitative assessment methods; however, there is room for improvement. This study aims to address these issues by applying the TARA framework, outlined in ISO/SAE 21434 for connected vehicles, to identify attack surfaces and conduct risk assessments of the Ballast Water Treatment System(BWTS), which is crucial for navigational safety. Moreover, the study conducts a comparative analysis of the quantitative risk assessments of IACS No. 171 and the TARA framework, proposing the need for and considerations of a new risk assessment framework, VeTARA, specifically tailored for ships. This research is expected to contribute to the enhancement of cyber risk management in maritime operations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1086-1091
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• 2022

The International Maritime Organization is establishing international agreements on maritime safety and security to prepare for the introduction of autonomous ships. In Korea, the industry is focusing on autonomous navigation system technology development, and to reduce accidents involving coastal ships, research on autonomous ship technology application plans for coastal ships is in progress. Interest in autonomously operated ships is increasing worldwide, and maritime demonstrations for verification of developed technologies are being pursued. In this study, a basic investigation was conducted on the design of a demonstration ship and an onshore platform (remote support center) using digital twin technology for application to coastal ships. To apply digital twin technology, an 8-m small battery-powered electric propulsion ship was selected as the target. The basic design of the twin-integrated platform was developed. The ship navigation and operation data were stored on a server system, and remote-control commands of the electric propulsion ship was achieved through communication between the ship and the onshore platform. Ship performance management, operation and operation optimization, and predictive control are possible using this digital twin technology. This safe and economical digital twin technology is applicable to ships responding to crisis scenarios.

• New & Renewable Energy
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• v.18 no.2
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• pp.73-81
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• 2022

This study was aimed at designing a condenser, as a component of the organic Rankine cycle system for ships. The condenser was manufactured through press molding to achieve a bent shape to enhance the heat transfer performance, considering the shape of the heat transfer plate used in a brazing plate heat exchanger. The heat transfer plate was made of copper-nickel alloy. The required heat transfer rate for the condenser was 110 kW, and the maximum number of layers was set as 25, considering the characteristics of high-temperature brazing. Computational fluid dynamics techniques were used to perform the thermal fluid analysis, based on the ANSYS CFX (v.18.1) commercial program. The heat transfer rate of the condenser was 4.96 kW for one layer (width and length of 0.224 and 0.7 m, respectively) of the heat transfer exchanger. The fin efficiency pertaining to the heat transfer plate was approximately 20%. The heat flow analysis for one layer of the heat exchanger plate indicated that the condenser with 25 layers of heat transfer plates could achieve a heat transfer rate of 110 kW.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.3
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• pp.451-458
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• 2022

In Korea, five major ports have been designated as sulfur oxide emission control areas to reduce air pollutant emissions, in accordance with Article 10 of the "Special Act on Port Air Quality" and Article 32 of the "Ship Pollution Prevention Regulations". As regulations against vessel-originated air pollutants (such as PM, CO2, NOx, and SOx) have been strengthened, the Ministry of Oceans and Fisheries(MOF) enacted rules that newly built public ships should adopt eco-friendly propulsion systems. However, particularly in diesel-electric hybrid propulsion systems,the demand for precise control schemes continues to grow as the fuel saving rate significantly varies depending on the control strategy applied. The conventional Power Take In-Power Take Off(PTI - PTO) mode control adopts a rule-based strategy, but this strategy is applied only in the low-load range and PTI mode; thus, an additional method is required to determine the optimal fuel consumption point. The proposed control method is designed to optimize fuel consumption by applying the equivalent consumption minimization strategy(ECMS) to the PTI - PTO mode by considering the characteristics of the specific fuel oil consumption(SFOC) of the engine in a diesel-electric hybrid propulsion system. To apply this method, a specific fishing vessel model operating on the Korean coast was selected to simulate the load operation environment of the ship. In this study, a 10.2% reduction was achieved in the MATLAB/SimDrive and SimElectric simulation by comparing the fuel consumption and CO2 emissions of the ship to which the conventional rule-based strategy was applied and that to which the ECMS was applied.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.365-370
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• 2004

At the present, e-commerce takes the place of existing transaction form in structure in the world trade by advancement of Information Technology and diffusion of Internet. There is no exceptions of this tendency even in industry of maritime and logistics. So, global shipping lines and logistics companies try to construct the e-Business network system for increasing their competitiveness in an are of cyber. However, in Korea, most of companies prefer "final handshake" as the traditional way of transaction to "e-commerce", because they bear a distrust in mind about the outflow of transaction information and security of settlement. So, number of companies using e-commerce is very small, and this situation causes the limited factor for activating the transaction structure of it. The rate of using e-commerce in logistics industry is lower than other industries, even more higher effectiveness is expected when they use it. Especially, it is very necessary not only e-commerce but also e-Logistics which can serve information of freight cost on cargo flow, operation cost and schedule, and tracing information of cargo. Increasing the necessity of e-Logistics, this study research the rate rf using e-Logistics focused on maritime and logistics companies, and analyze the transaction form among members of these industries for improving them. In detail, this paper examine the drivers for activating e-Logistics, and present the effective factors for a successful development of these industries.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.211-212
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• 2022

지구온난화에 따른 우리나라 주변 환경의 변화와 최근 중국 불법어선의 연근해 어업자원의 고갈 등으로 인해 우리나라 연근해 어족자원을 보호할 필요성이 증대되고 있으며, 지속 가능한 어업을 위해서는 어획물의 종류와 양을 정확히 파악하고 불법 어업에 대한 철저한 감시 및 관리가 필요하다. 시공간적으로 다양하게 변하는 생태 및 어장 환경 정보와 선박에 대한 정보를 통해 해양관측과 위성 원격탐사를 동시에 이용함으로써 근해와 원양 생물자원 실태를 관측하는 것이 가능하다. 본 연구에서는 야간 불빛 위성 Suomi-NPP (Suomi National Polar-orbiting Partnership) 및 후속위성인 NOAA-20의 VIIRS (Visible Infrared Imaging Radiometer Suite) DNB (Day & Night Band) 영상을 이용하여 야간 불빛을 활용하고자 한다. 이 불빛 위성 자료를 이용하여 야간에 조업하는 어선 선단의 공간 분포를 분석할 수 있다. 또한 이 불빛 위성 자료와 AIS 자료를 상호 비교하여, 불빛 위성 자료를 통해 실제 선박의 위치 정보를 검색하는 것이 가능함을 검증하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.160-161
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• 2023

Currently, the ship's passage planning relies on the navigator officer's knowledge and empirical methods. However, as ship autonomous navigation technology has recently developed, automation technology for passage planning has been studied in various ways. In this study, we intend to generate an optimal route for a ship based on Q-learning, one of the reinforcement learning techniques. Reinforcement learning is applied in a way that trains experiences for various situations and makes optimal decisions based on them.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.23-29
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• 2022

To detect harmful chemical substances in seawater, we fabricated a prototype sensor and evaluated its performance. The prototype sensor consisted of a detector, housing, and driving circuit. We built the detector by printing an Indium-Tin-Oxide (ITO) nanoparticle film on a flexible substrate, and it had two detection parts for simultaneous detection of temperature and HNS concentration. The housing connected the detector and the driving circuit and was made of Teflon material to prevent chemical reactions that may affect sensor performance. The driving circuit supplied electric power, and display measured data using a bridge circuit and an Arduino board. We evaluated the sensor performances such as response (ΔR), the limit of detection (LOD), response time, and errors to confirm the specification.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.366-368
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• 2022

지구온난화에 따른 우리나라 주변 환경의 변화와 최근 중국 불법 어선의 연근해 어업 자원의 고갈 등으로 인해 우리나라 연근해 어족자원을 보호할 필요성이 증대되고 있으며, 지속 가능한 어업을 위해서는 어획물의 종류와 양을 정확히 파악하고 불법 어업에 대한 철저한 감시 및 관리가 필요하다. 이러한 시공간적으로 다양하게 변하는 생태 및 어장 환경 정보와 선박에 대한 정보를 통해 해양관측과 위성 원격탐사를 동시에 이용함으로써 근해와 원양 생물자원 실태를 관측하는 것이 가능하다. 본 연구에서는 NOAA-20 위성의 VIIRS (Visible Infrared Imaging Radiometer Suite) DNB (Day & Night Band) 영상을 기반으로 추정한 야간 불빛 자료를 활용하고자 한다. DNB 불빛 영상은 낮은 조도의 불빛을 감지하여 그 정보를 보여 준다. 야간 불빛 자료에 포함된 구름 부분을 마스킹하기 위해 NASA의 신규알고리즘이 적용된JPSS-JRR-CloudMask 기술을 이용하였다. 이번 연구에서는 구름의 영향이 없는 날짜를 선별한 후 AIS 정보에서 어선의 정보를 추출하여 검증 자료로 사용하였다. 실제 선박의 정보를 이용한 위성 불빛 자료의 검증을 통해 위성자료의 신뢰성을 확보하고 향후 불빛과 선단 규모의 상관관계 분석 및 어선의 분포 경향 분석을 통하여 우리나라의 어장환경 분석에 활용 가능할 것으로 기대한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.659-665
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• 2023

The exciter of a ship generator adjusts the magnetic flux through excitation current control to maintain the output terminal voltage constant. The voltage controller inside the exciter typically uses a proportional integral control method. however, the response characteristics determined by the gain and time constant produce unwanted output owing to an inappropriate setting value that can reduce the quality and stability of power within the ship. In this study, a neural network circuit is learned using stable input/output data that can be obtained through the AC4A type exciter model provided by IEEE, and the simulation is performed by replacing the existing proportional integral control type voltage controller with the learned neural network circuit controller. Consequently, overshooting was improved by up to 9.63% compared with that of the previous model, and excellence in stable response characteristics was confirmed.