• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1327-1330
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• 2004

An underwater robotic system has been developed and applied to visual inspection of reactor vessel internals. The Korea Electric Power Robot for Visual Test (KeproVt) consists of an underwater robot, a vision processor-based measuring unit, a master control station and a servo control station. The robot guided by the control station with the measuring unit can be controlled to have any motion at any position in the reactor vessel with $\pm$1 cm positioning and $\pm$2 degrees heading accuracies with enough precision to inspect reactor internals. A simple and fast installation process is emphasized in the developed system. The developed robotic system was successfully deployed at the Younggwang Nuclear Unit 1 for the visual inspection of reactor internals.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.60-63
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• 2004

An innovative in-core neutron flux mapping system has been developed and applied successfully for service in a commercial pressurized water reactor. With the benefit of double indexing path selector (Dip $s^{ⓡ}$) mechanism, the reliability of the detector drive system has been improved five times higher than that of conventional systems, and the problems caused by the serious friction generated between the detector cable and guide tubing has been solved completely because the Dip $s^{ⓡ}$ architecture allows the detector guide tubings to have larger curvature and shorter length in nature. The simple and fast maintenance is particularly emphasized in the detector drive system to secure minimum radiation exposure to the maintenance personnel by optimizing the number of components and providing easy access to the components. The programmable logic controller based digital controller with Window $s^{ⓡ}$ based operator s console provides fully automated and user friendly operation and maintenance support means.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.6
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• pp.637-644
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• 2005

This paper describes the numerical simulation of the interaction between longitudinal vortices ("common flow up") and a 3-D turbulent boundary layer over a flat plate To analyze the common flow up Produced from vortex generators. the flow field behind the vortex generators Is modeled by the information that is available from studies on a half-delta winglet. Also. the Reynolds-averaged Navier-Stokes equation for three-dimensional turbulent flows. together with a two-layer turbulence model to resolve the near-wall flow, is solved by the method of AF-ADI. The computational results predict that the boundary layer is thinned in the regions where the secondary flow is directed toward the wall and thickened where it is directed away from the wall Also. the numerical results. such as Reynolds stresses. turbulent kinetic energy and skin friction characteristics generated from the vortex generators . are reasonably close to the experimental data.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.341-346
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• 2000

A numerical simulation has been carried out for the engine cooling system. It is the important element to analysis of heat transfer process in cooling system for an automotive engine. Thus, the purpose of this simulator is to present useful information at the early stages of the design of the cooling system by enabling the development engineer to predict performance trends. This program has useful window interface for analysis of the cooling system and it is convenient for user to control data with relational database. The system was simulated and compared with experimental data. As a result, the inlet, outlet temperature of the radiator by the simulator agrees well with it. It is concluded that this simulation program is available in developing the cooling system for a new car.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.578-587
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• 2009

In this paper, the characteristics of incompressible flow in a tube type marine fuel oil filter have been investigated. Fluent program has been used to obtain the solutions for the problems of three-dimensional, turbulent fuel oil flow in a filtering system. The inlet flow field is assumed to be uniform. The velocity and pressure distributions were obtained using Darcy's law. The increase of inlet velocity for cleaning fuel oil may cause some problems like vibration of the filter element. It was also required to consider the distribution of cleaning velocity because the worst distribution of cleaning velocity may cause the local insufficient cleaning effect and furthermore the effective filtration area can be reduced. The simulated results show that the computer code can be successfully applied for simulation of the complex base oil flow through the porous media. This paper could be applied to the design of auto-backwashing filtering system as design factor.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.6
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• pp.802-813
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• 2000

This paper represents numerical computations of the interaction between the longitudinal vortex and a flat plate 3-D turbulent boundary layer. In the present study, the main interest is in the behavior of longitudinal vortices introduced in turbulent boundary layers. The flow field behind vortex generator is modeled by the information that is available from studies on the delta winglet. Also, the Reynolds-averaged Navier-Stoke equations for three-dimensional turbulent flows, together with a two-layer turbulence model to resolve the near-wall flow, is solved by the method of pseudo compressibility. The present results show that the boundary layer is thinned in the regions where the secondary flow is directed toward the wall and thickened where it is directed away from the wall, and have a good agreement with the experimental data.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.12
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• pp.1595-1607
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• 1997

The natural convection of a horizontal layer heated from below in a three-dimensional rectangular enclosure was dealt with both numerically and experimentally. The aspect ratios are 1:2:3.5 and Boussinesq fluid is water with the Prandtl number of 5.0. This experimental study showed how to measure the variation of temperature field in a 3-D rectangular enclosure with small aspect ratios by using TLC(Thermochromic Liquid Crystal) and color capturing technique. The experimental temperature field had periodic characteristics of 75 sec at Ra=2.37*10$^{5}$ . But the numerical convection flow had periodic characteristics of 79 sec at the same Rayleigh number. In three dimensional computation it was found that the convection roll structure bifurcated from four rolls to two rolls as the Rayleigh number is increased.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.353-358
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• 2000

This paper presents the experimental investigation about miniature heat pipe for notebook PC. The focus of analysis is the operating temperature not to exceed $65^{\circ}C$ maximum allowable CPU surface temperature. Copper is used to heat pipe material and brass is wick material, and working fluid is selected to water. This cooling system is heat spreader method using a aluminum plate, since this method is most commonly used. According to the present study, heat for 3mm heat pipe, 8W, and for 4mm heat pipe, 10W, is found to power dissipation limit respectively, Soon after this investigation, sufficient long term life test should be followed.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.416-417
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• 2016

축구 경기에서 패스는 경기력에 있어서 중요한 요소를 차지하고 있다. 특히, 공격지역에서 패스와 경기의 승리가 밀접한 관련이 있을 것이라고 예상된다. 이를 좀 더 객관적으로 분석하기 위해서 2014년 K리그 클래식 전 경기 268경기에 관해서 팀별 패스 관련 데이터를 이용하여 연관성을 분석해보았다. 전체 패스, 공격 1/3 지역 패스, PA지역 패스 횟 수와 슈팅 및 골의 횟 수를 상관 분석 및 다중 회귀분석을 통해 그 연관성을 분석해 본 결과 골 수와 패스 횟 수 사이의 큰 관계는 없는 것으로 나타났다.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.121-128
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• 1996

농업 기상 자료의 수집 및 식물병 예찰 절차를 통합한 시스템을 -32비트 개인용 컴퓨터 운영 체계인 OS/2에서 개발하였다. 통합 시스템은 무인기상관측기(AWS)로부터 자료 수집을 하는 절차, 준실시간 기상자료로부터 병예찰을 하는 절차, 기상 정보와 병예찰 정보를 글과 그림으로 출력하는 절차의 세 부분으로 나뉘어 있다. 통합 시스템은 여러 지역의 실시간 기상 자료를 수집하며 기상 자료를 이용하여 각 지역의 병예찰 정보를 즉시 생성한다. 본 연구에서는 기상 자료를 이용한 병예찰 모형의 예로서 도열병 예찰 시뮬레이션 모형을 사용하였다. 또한 식물병 예찰을 위하여 무인기상관측기가 갖추어져야 하는 최소한의 요구 사항을 검토하였다. 본 시스템은 각종 식물병 예찰 모형의 개발과 관련하여 각 모형의 구동을 위하여 쓰여질 수 있을 것이다. 현재 각 농촌진흥원과 지도소에는 많은 수의 무인기상관측기가 설치되어 있으므로 이를 이용하여 본 시스템을 실용화 할 수 있을 것이다.