• Journal of Welding and Joining
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• 제27권2호
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• pp.32-37
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• 2009

In shipyard, plate forming is widely used to form the ship hull plate in various shapes. Line heating method by using a flame torch is one of the major shipbuilding processes carried out by skilled workers. Since the forming characteristics depend upon their experiences in manual forming, there are much variations between products and difficulties in communication between engineers and workers. Hence, it needs to develop an automatic forming system which can not only reduce the working time and rework costs but also improve the working environment and hull forming productivity. One of the final goals of plate forming automation is to form a target shape from the initial plate automatically. For automated plate forming, it is required to determine where and how to heat on the plate. To realize this procedure, the inverse problem should be first solved and the effect of curvature shape formed at the heating path should be investigated. In this study, the inverse problem was solved by geometrical approach using the relationship between bending angle and radius of curvature of the curved shape. In addition, experiments of two-dimensional plate forming were performed with the distance-based method considering the curved bending with curvature. The result of the formed shape agreed considerably well with the target shape.

• 한국산학기술학회논문지
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• 제13권1호
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• pp.1-7
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• 2012

선박설계에 있어서 설계효율 향상 및 설계품질 확보를 위해서는 설계 자동화 시스템의 구축이 필수적이다. 이를 위해서는 조선전용 3차원 CAD 시스템의 개발과 함께 여러 설계 공정에서 발생되는 설계정보를 충돌 없이 자연스럽게 반영해 줄 수 있는 설계 정보 관리 소프트웨어들이 개발되어야 한다. 설계 정보 관리가 요구되는 대표적인 예로서 선체 의장품 시공에 필요한 의장 홀의 설계 과정을 들 수 있다. 설계 기간 중 빈번하게 발생하는 의장 부서로부터의 홀 시공 요구에 대하여 구조 설계 부서는 구조 안정성과 적합성을 고려하여 검토하고 반영 여부를 의장 부서로 통보하게 되며, 결정 시까지 부서간의 업무 협의, 토론, 관련 도면 작성 등 많은 설계자원이 투입된다. 본 논문에서는 이러한 의장 홀 설계 과정을 자동화하기 위한 홀 플랜 시스템의 기본 개념 소개와 함께 프로세스 자동화 방안을 제시한다.

• 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.

• 대한조선학회논문집
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• 제30권3호
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• pp.90-99
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• 1993

선체 구조해석에서 유한요소의 활용에 따라 3차원적인 모델이 필요하게 되었으나 선체구조는 매우 복잡하고 주문생산에 따른 선체규격의 상이함에 의해 유한요소 모델링에 어려움이 많다고 할 수 있다. 유한요소 소프트웨어에서 제공하는 pre-processor나 geometric modeler를 활용하여 모델링을 짧은 시간내 편리하게 하기 위해서는 DB에 저장된 설계 데이타로 부터 요소형성에 긴요한 데이타들을 추출하여 사용할 필요가 있게 된다. 본문에는 engineering database의 부분적인 구현 예로서, 설계-해석 자동화의 한 분야인 유한요소 모델링에 필요한 내용들이 설계 데이터로 부터 추출되어 관계형 데이타 테이블로 정형화되는 과정이 개념적으로 나타나 있다.

• 한국항행학회논문지
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• 제28권2호
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• pp.210-215
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• 2024

선박의 자동화 수준이 높아지고 자율운항선박의 개발에 따라 선박의 IPMS (integrated platform management system)는 다양한 운영체제로 통제되는 개별 장비들을 통합하고 다량의 데이터를 실시간으로 처리해야 한다. 이러한 상황에서 데이터 처리를 위해 DDS (data distribution service) 미들웨어 기반 선박 IPMS 시뮬레이터를 개발하고 성능을 평가하였다. 이종 운영체제로 동작하고 있는 신호입출력장치와 IPMS 서버에서 초당 1,000개의 토픽을 비동기로 발간하고 구독한 시뮬레이션을 수행하였으며, 초기 4초 동안 일부 토픽의 누락을 제외하고는 오류 없이 데이터를 수신하였다. 개발된 시뮬레이터는 실제 선박에서 DDS를 이용하여 다른 제어체계를 통합할 수 있음을 보여준다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권5호
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• pp.2103-2123
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• 2018

Ships built today are larger in scale and feature more complex structures. The ever-evolving systems used on board a ship require vast amounts of data processing. In the future, with the advent of smart ships, unmanned ships and other next-generation ships, the volumes of data to be processed will continue to increase. Yet, to date, ship data has been processed using wired networks. Placed at fixed locations, the nodes on wired networks often fail to process data from mobile devices. Despite many attempts made to use Wi-Fi on ships just as on land to create wireless networks, Wi-Fi has hardly been available due to the complex metal structures of ships. Therefore, Wi-Fi on ships has been patchy as the ship-wide total Wi-Fi coverage has not properly implemented. A new ship-wide wireless network environment is part of the technology conducive to the shipbuilding industry. The wireless network environment should not only serve the purpose of communication but also be able to manage and control multiple features in real-time: fault diagnostics, tracking, accident prevention and safety management. To better understand the characteristics of wireless frequencies for ships, this paper tests the widely used TETRA, UHF and Wi-Fi and sheds light on the features, advantages and disadvantages of each technology in ship settings. The proposed deployment of a Super Wi-Fi network leveraging the legacy UHF system of TMS generates a ship-wide wireless network environment. The experimental findings corroborate the feasibility of the proposed ship-wide Super Wi-Fi network environment.

• 한국해양공학회지
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• 제17권1호
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• pp.72-79
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• 2003

This paper deals with the development of an interface program for automatic plate forming, which can exchange information between the heating line information generation program and the automatic heating apparatus. In this paper, the performance of the developed interface program has been verified from the view point of numerical position control. By applying the interface program to the operation of the automatic heating apparatus, an experiment of line heating has been conducted for several steel plate models. Based on the experimental results, a simplified relation to estimate angular distortion has keen derived as a natural characteristic of the present automatic heating apparatus. As a result of the present study, the prototype of the automatic plate forming system has been constructed, and its application to the real surface models found in the ship will be presented in the near future.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.90-96
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• 2021

The logistics market is continuously growing due to the development of technology and the growth of the online market. In addition, the social atmosphere that emphasizes non-face-to-face due to the pandemic situation is accelerating the growth of logistics. Delivery of goods ordered online requires delivery process through courier worker. In order for the courier worker to ship the product, the work of loading the product on the truck must be preceded. The accident caused by such delivery and loading work is increasing and it is emerging as a social problem. This study proposes a robot-based automated loading system to efficiently handle the increasing volume of courier service and to construct a more efficient and safe working environment by replacing the physical labor that was overloaded to courier workers. The proposed system replaces the loading of the courier worker and proposes the optimal loading function through the automation system.

• 한국산학기술학회논문지
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• 제12권2호
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• pp.852-857
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• 2011

조선업종은 숙련공의 감소와 노동력 부족을 해결하기 위해 자동화와 기계화가 필요하다. 특히 조선용 핸드레일 제조공정은 표준화된 타 분야와 달리 자동화가 낙후되어 있다. 본 연구에서는 조선용 핸드레일 제작에 사용할 수 있는 철의장 가공자동화시스템을 설계하고 개발하였다. 시스템의 기구부는 절단공정의 효율성, 생산성, 안정성 등을 고려하여 설계하였고, CATIA 와 ANSYS를 사용하여 구조물의 안정성을 확인하였다. 시스템 제어부는 개방성과 확장성을 제공하는 PCNC 콘트롤러를 사용하였고, 터치스크린 방식의 화면 조작을 통해 시스템의 제어 및 모니터링을 할 수 있도록 구축하였다. 개발된 철의장 가공자동화시스템은 수차의 구동테스트 및 가공테스트를 통해 성능의 우수성을 입증하여 실용단계에 있다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.116-128
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• 2020

In the shipbuilding industry, three-dimensional (3D) templates play a key role in the completeness evaluation of shell plates with a large curvature in the shell-plate fabrication process. Currently, the information of 3D templates from a ship computer-aided design system is limited; thus, manufacturers depend on their experience to produce the templates manually. This results in the inaccuracy of templates in addition to increased production time. Therefore, if the pieces of the 3D templates can be produced automatically with accurate information, the lead time of the fabrication process can be reduced. In this study, we define a new type of template piece and develop methods for extending a boundary template and converting manufacturing information into numerical control machine input. In addition, based on the results of the study, we propose a production automation system for 3D template pieces. This system is expected to reduce the lead time of the fabrication process.