• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 추계학술발표회
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• pp.29-29
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• 2017

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 추계학술발표대회 요약집
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• pp.446.2-446.2
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• 2003

• Nuclear Engineering and Technology
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• 제44권6호
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• pp.683-688
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• 2012

The structural integrity of mechanical components during several transients should be assured in the design stage. This requires a fatigue analysis including thermal and stress analyses. As an example, this study performs a fatigue analysis of the reactor pressure vessel of SMART during arbitrary transients. Using heat transfer coefficients determined based on the operating environments, a transient thermal analysis is performed and the results are applied to a finite element model along with the pressure to calculate the stresses. The total stress intensity range and cumulative fatigue usage factor are investigated to determine the adequacy of the design.

• 한국유체기계학회 논문집
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• 제17권6호
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• pp.77-83
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• 2014

The vessel of integral reactor contains its major primary components such as the fuel and core, pumps, steam generators, and a pressurizer, so its size is proportional to the required space for the installation of each component. The steam generators take up the largest volume of internal space of reactor vessel and their volumes is substantial for the overall size of reactor vessel. Reduction of installation space for steam generators can lead to much smaller reactor vessel with resultant decrease of overall cost for the components and related facilities. A printed circuit heat exchanger is one of the compact types of heat exchangers available as an alternative to conventional shell and tube heat exchangers. Its name is derived from the procedure used to manufacture the flat metal plates that form the core of the heat exchanger, which is done by chemical milling. These plates are then stacked and diffusion bonded, converting the plates into a solid metal block containing precisely engineered fluid flow passages. The overall heat transfer area and pressure drops are evaluated for the steam generator based on the concept of the printed circuit heat exchanger in this study. As the printed circuit heat exchanger is known to have much larger heat transfer area density per unit volume, we can expect significantly reduced steam generator compared to former shell and tube type of steam generator. For the introduction of new steam generator, two design requirements are considered: flow area ratio between primary and secondary flow paths, and secondary side parallel channel flow oscillation. The results show that the overall volume of the steam generator can be significantly reduced with printed circuit type of steam generator.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.554-564
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• 2022

The natural circulation phenomena occurring in fully integrated nuclear reactors are associated with a unique formation mechanism. The phenomenon results from a structural feature of these reactors involving upward flow from the core, located in the central-bottom region of a single vessel, and downward flow to the steam generator in the annulus region. In this study, to understand the natural circulation in a single vessel involving a multi-layered flow path, single-phase and two-phase natural circulation tests were performed using the SMART-ITL facility, and validation analysis of the TASS/SMR-S code was performed by comparing the corresponding test results. Three single-phase natural circulation tests were sequentially conducted at 15%, 10%, and 5% of full-scaled core-power without RCP operation, following which a two-phase natural circulation test was successively conducted with an artificial discharge of coolant inventory. The simulation capability of the TASS/SMR-S code with respect to the natural circulation phenomena was validated against the test results, and somewhat conservative but reasonably comparative results in terms of overall thermalhydraulic behavior were shown.

• IEIE Transactions on Smart Processing and Computing
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• 제6권2호
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• pp.76-84
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• 2017

This paper presents an efficient method for generating spatiotemporal images in order to detect leukocyte motion in microvessels. Leveraging the constraint that leukocytes move along the contour line of the blood vessel wall, our proposed method efficiently generates spatiotemporal images for leukocyte motion detection. To that end, translational motion caused by in vivo movement is first removed by a template matching method. Second, the blood vessel region is detected by an automatic threshold selection method in order to binarize temporal variance images. Then, the contour of the blood vessel wall is expressed via B-spline function. Finally, using the detected blood vessel wall's contour as an initial curve, the plasma layer for the most accurate position is determined in order to find the spatial axis via snake, and the spatiotemporal images are generated. Experimental results show that the spatiotemporal images are generated effectively through comparison of each step with three images.

• 한국정보통신학회논문지
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• 제17권11호
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• pp.2708-2716
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• 2013

본 논문에서는 지능형 디지털 선박의 추진 시스템에서 요구되는 임베디드 원격 모니터링 진단 시스템 개발에 관하여 기술하였다. 원격 모니터링 진단 시스템은 크게 선박 통합 관리시스템, 서버, 원격 모니터링을 담당하는 전용 휴대용 단말기와 상용 스마트폰으로 구성되며, 이를 위하여 사용자 중심의 UI 환경을 가진 통신 프로토콜을 설계하였다. 제안된 시스템은 효율적인 이중구조 통신채널로서 원격 모니터링 시스템에서 간편하면서도 효율적인 통신 프로토콜을 제공하며, 오작동하는 무선통신 채널은 즉시 교체된다. 본 시스템에서는 LCD 화면을 위해 효율적인 임베디드 리눅스 UI를 개발하였으며, 개발된 무선 모니터링 시스템을 평가하기 위하여 실제로 디지털 선박에서 성능을 검증하였다.

• International journal of advanced smart convergence
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• 제11권4호
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• pp.88-95
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• 2022

Vacuum simulation is associated with the prediction and calculation of how materials, pumps and systems will perform using mathematical equations. In this investigation, three different high vacuum systems were simulated and estimated with each vacuum characteristics by VacTran simulator. In each of modelled vacuum systems, selection of gas loads into vessel, combination of rough and high vacuum pumps and dimension of conductance elements were proposed as system variables. In pump station model, the pumping speed to pressures by the combination of root pump was analyzed under the variations of vessel volume. In this study, the effects of outgassing dependent on vessel materials was also simulated and aluminum vessel was estimated to optimum materials. It was obtained from the modelling with diffusion pump that the diameter, length of 50×250[mm]roughing line was characterized as optimum variables to reach the ultimate pressure of 10E-7[torr]. Optimum design factors for vacuum characteristics of modelled vacuum system were achieved by VacTran simulator. Feasibility of VacTran as vacuum simulator was verified and applications of VacTran in high tech process expected to be increased.

• 한국전자통신학회논문지
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• 제17권1호
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• pp.167-172
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• 2022

현재 광양항을 비롯한 수출입 항만에서 선박의 관제, 예선, 도선 작업은 선사와 상관없이 입출항 순서 등과 같은 요소에 따라 공동 배선제로 운영되고 있다. 또한, 이것마저도 수작업에 의해서 매우 비효율적으로 이루어 지고 있다. 따라서 선박의 접·이안 등에 대한 업무의 표준화와 디지털화를 통하여 항만 및 선박 운용의 효율성을 높이기 위한 시스템의 개발이 절실히 요청되고 있다. 본 연구에서는 선박의 위치정보, 도예선 스케쥴, 입출항 운영정보, 기상정보 등과 같은 빅데이터에 기반한 스마트 항만 운용시스템을 설계하여 항만 및 선박 운용의 효율성을 높이는 방안을 제시하였다.

• 해양환경안전학회지
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• 제24권5호
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• pp.504-510
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• 2018

해양사고는 주로 충돌과 좌초에 의한 것으로 인적과실이 원인이다. 한국형 e-Navigation 사업은 인적과실에 의한 해양사고 저감 및 초고속 해상무선통신(LTE-Maritime)의 구축 방안을 마련하고 있다. 그에 따른 사고취약선박 모니터링 지원 서비스(SV10)는 육상에서 수집한 선박의 위치정보를 기반으로 선박의 충돌 좌초 위험도를 평가하여 선박이 위험상황을 인식할 수 있도록 정보를 제공하고 해양사고 발생 시 육상에서 조기 대응할 수 있도록 실시간 선박 위치 및 위험상황 정보를 유관기관과 공유하는 서비스이다. 본 연구에서는 중앙해양안전심판원에서 제공된 해양사고 통계연보 및 재결서를 분석하여 SV10 서비스로 저감될 수 있는 해양사고 비율을 확인하였다.