• Journal of Welding and Joining
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• 제14권6호
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• pp.119-130
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• 1996

용접은 조선공업의 핵심기술의 하나로서 용접작업의 장치화와 자동화를 통한 생산성 향상은 선박의 건조비 절감에 기여하는 바가 크다. 용접의 품질과 생산성은 엔지니어링 부서로부터 제공되는 관련정보의 질과 적합성에 많이 의존한다. 본고는 선박의 설계에서 생산에 이르기까지의 정보를 통합한 조선 CIMS구축에 활용될 수 있는 선박 용접 정보 시스템에 관하여 연구하였다. 이를 위하여 기존 용접정보의 생성과정과 내용을 체계적으로 분석하고 객체지향기법을 적용하여 복잡 다양한 선박의 용접 정보를 모델링 하였다. 또 이들 객체지향 모델을 지원하면서 방대한 양의 선박 용접정보를 신속하고 정확하게 처리하는 데이터베이스를 구축하였다. 개발시스템은 산적화물선을 대상으로 하였으며 사건구동 방식의 프로그래밍 기법을 적용하고 그래픽 사용자 환경을 구현하여 사용자의 편의성을 제고하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2023년도 춘계학술대회
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• pp.160-161
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• 2023

현재 선박의 항해계획은 항해사의 지식과 경험적인 방법에 의존하고 있다. 그러나 최근에는 선박 자율운항기술이 발전됨에 따라, 항해계획의 자동화 기술도 여러 가지 방법으로 연구되고 있다. 본 연구에서는 강화학습 기법 중 하나인 Q-러닝을 기반으로 선박 최적 항해 경로를 생성하고자 한다. 강화학습은 다양한 상황에 대한 경험을 학습하고, 이를 기반으로 최적의 결정을 내리는 방식으로 적용된다.

• 해양환경안전학회지
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• 제30권3호
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• pp.263-274
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• 2024

The digitization of ship environments has increased the risk of cyberattacks on ships. The smartization and automation of ships are also likely to result in cyber threats. The International Maritime Organization (IMO) has discussed the establishment of regulations at the autonomous level and has revised existing agreements by dividing autonomous ships into four stages, where stages 1 and 2 are for sailors who are boarding ships while stages 3 and 4 are for those not boarding ships. In this study, the level of a smart ship was classified into LEVELs (LVs) 1 to 3 based on the autonomous levels specified by the IMO. Furthermore, a risk assessment for smart ships at various LVs in different risk scenarios was conducted The cyber threats and vulnerabilities of smart ships were analyzed by dividing them into administrative, physical, and technical security; and mitigation measures for each security area were derived. A total of 22 cyber threats were identified for the cyber asset (target system). We inferred that the higher the level of a smart ship, the greater the hyper connectivity and the remote access to operational technology systems; consequently, the greater the attack surface. Therefore, it is necessary to apply mitigation measures using technical security controls in environments with high-level smart ships.

• International Journal of Control, Automation, and Systems
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• 제3권3호
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• pp.486-492
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• 2005

A practical recursive WLS (weighted least squares) algorithm is proposed to estimate relative range using LOS (line-of-sight) information for ASM (anti-ship missile) application. Apart from the previous approaches based on the EKF (extended Kalman filter), to ensure good convergence properties in long range engagement situations, the proposed scheme utilizes LOS rate measurements instead of conventionally used LOS angle measurements. The estimation error property for the proposed filter is investigated and a simple error compensator is devised to enhance its estimation error performances. Simulation results indicate that the proposed filter produces very accurate range estimates with extremely small computations.

• 한국지능시스템학회논문지
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• 제15권4호
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• pp.418-424
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• 2005

선박의 안전 운항과 운항 경비의 절감을 위해 선박의 운항 자동화 및 지능화 기술이 요구된다. 선박의 자동화를 위해서는 GPS와 전자해도에 기반한 항해시스템의 항로 계획이 선행되어야 한다. 본 논문에서는 항해시스템의 자동화된 항로 계획을 위해 장애물의 접점 산출 기법과 이를 이용한 트리 생성 기법, 그리고 생성된 트리 구조를 기반으로 한 항로 산출 기법을 제안한다. 제안한 항로 산출 기법의 효율성 검증을 위해 최적화 관점에서 대표적 항로 계획 기법인 A*기법과 비교$\cdot$분석한다.

• 한국정보통신학회논문지
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• 제3권1호
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• pp.141-153
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• 1999

본 논문은 INMARSAT-C를 통하여 육상의 인터넷 메일이나 웹 사용자와 선박간 편리한 메시지 송수신 서비스를 제공하는 인터넷 기반의 메시지 전송 에이전트의 설계 및 구현에 대해서 논한다. 이를 위하여 육상과 선박간 통신을 위한 전체적인 시스템 구성, 에이전트의 구성 모듈, 송ㆍ수신 데이터의 관리를 위한 데이터베이스를 설계, 구현한다. 본 논문의 타당성 검토를 위하여 메시지 파싱(parsing), 데이터베이스, 메시지 포맷, X.25 인터페이스 등의 모듈을 구현하여 시험하고, 그 결과를 토대로 선박 내 데이터베이스 접근과 더불어 선박 자동화 시스템의 가능성을 논한다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2012년도 춘계학술대회
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• pp.110-112
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• 2012

Education and training of technical staff for the new generation technological equipment has a vital importance for developing countries in order to maintain sustainable development and keep up with new generation technologies. Mechatronics the synergistic combination of mechanical, electronic and software engineering from an engineering perspective to serve the purposes of controlling advanced hybrid systems is a product of new generation technology which can be given as a sample to this phenomenon. Recent marine engines are combination of heavy industry with high technology. Nowadays, ships are built in full automation and equipped with computer controlled mechatronics systems. However, finding qualified officer and engineers who can operate, maintain, control and repair when it is required such full automatic systems with knowledge of a new generation system became a serious issue. Due to importance of this fact STCW Manila amendment has new training and certification requirements for electro-technical officers. In this paper, Mechatronics applications on ship are introduced, importance of it highlighted and a new syllabus is proposed for the training of marine engineers to be nurtured with mechatronics knowledge as it is required.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.719-723
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• 1997

The welding automation in ship manufacturing process,especially in the sub-assembly line is considered to be a difficult job because the welding part is too huge, various, unstructured for a welding robot to weld fully automatically. The weld orocess at the sub-assembly line for ship manufacturing is to joint the various stiffener on the base panel. In order to realize automatic robot weld in sub-assembly line, robot have to equip with the sensing system to recognize the position of the parts. In this research,we developed a vision system to detect the position of base panle for sub-assembly line is shipbuilding process. The vision system is composed of one CCD camera attached on the base of robot, 2-500W halogen lamps for active illumination. In the image processing algorithm,the base panel is represented by two set of lines located at its two corner through hough transform. However, the various noise line caused by highlight,scratches and stiffener,roller in conveyor, and so on is contained in the captured image, this nosie can be eliminated by region segmentation and threshold in hough transform domain. The matching process to recognize the position of weld panel is executed by finding patterns in the Hough transformed domain. The sets of experiments performed in the sub-assembly line show the effectiveness of the proposed algorithm.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권1호
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• pp.162-174
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• 2014

Most shipbuilding scheduling research so far has focused on the load level on the dock plan. This is because the dock is the least extendable resource in shipyards, and its overloading is difficult to resolve. However, once dock scheduling is completed, making a plan that makes the best use of the rest of the resources in the shipyard to minimize any additional cost is also important. Block assignment planning is one of the midterm planning tasks; it assigns a block to the facility (factory/shop or surface plate) that will actually manufacture the block according to the block characteristics and current situation of the facility. It is one of the most heavily loaded midterm planning tasks and is carried out manually by experienced workers. In this study, a method of representing the block assignment rules using a diagram was suggested through analysis of the existing manual process. A block allocation program was developed which automated the block assignment process according to the rules represented by the diagram. The planning scenario was validated through a case study that compared the manual assignment and two automated block assignment results.

• Journal of Power Electronics
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• 제13권1호
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• pp.70-76
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• 2013

For high power high step-down dc-dc conversion applications, conventional three-level dc-dc converters are subject to extreme duty cycles or increased volume and cost due to the use of transformers. In this paper, a transformerless three-level dc-dc buck converter with a high step-down conversion ratio is proposed. The converter comprises two asymmetrical half bridges, which are of the neutral point clamped structures. Therefore, the output pulse voltage of the converter can be obtained in terms of the voltage difference between the two half bridges. In order to realize harmonious switching of the converter, a modulation strategy with capacitor voltages self balance is presented. According to the deduced output dc voltage function, transformerless operation without extreme duty cycles can be implemented. Experimental results from a 1kW prototype verify the validity of the proposed converter. It is suitable for ship electric power distribution systems.