• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2_spc
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• pp.275-289
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• 2020

In 2017, multimodal transportation tests for evaluating road, sea, and rail transport were performed by research institutes in the US, Spain, and the Republic of Korea. In this study, acceleration and strain data determined through road and sea tests were analyzed. It was investigated whether the load generated for each transport mode was amplified or attenuated according to the load transfer path. From the results, it was confirmed that the load transfer characteristics differed according to the transportation mode and loading path. The effects of strain determined through each test on the structural integrity of the spent nuclear fuel were also investigated. It was found that the magnitude of the measured strain had a negligible effect on the structural integrity of the spent nuclear fuel, considering its fatigue strength. The results for the acceleration and strain data analyses obtained in this study will be useful for scheduled domestic transportation tests under normal transport conditions.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.129-142
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• 2005

A semi-monocoque truncated cone structure, which is a main structure for the payload adapter of KSLV-I, was designed. Static test was performed to confirm the reliability of the cone structure under the design loads. Strains and displacements are measured during four load cases; the compressive axial, pure bending, pure shear, and combined loading conditions. The results showed that the cone structure satisfies the design requirements. An equivalent axial load was applied to the cone structure so that the global buckling of the cone structure occurred. The measured buckling load was compared with the predicted one by finite element method. The results show a good agreement.

• Proceedings of the Korean Reliability Society Conference
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• 2000.04a
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• pp.115-121
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• 2000

영광1,2,3,4호기 비상디젤발전기(EDG)의 신뢰도 수준을 파악하기 위하여 시험관리대장과 운전불능관리대장, 그리고 발전과장일지를 조사하여 신뢰도 및 이용불능도를 분석하였다. 신뢰도는 EDG의 유효시험 데이터를 이용하여 계산하는 유효 신뢰도와 무효시험까지 포함하여 계산하는 전체 신뢰도로 구분하였으며, 이용불능도는 EDG를 정비모드로 전환시키고 작업함으로서 이용불능을 유발하였던 정비 이용불능도, 그리고 유효시험 실패로 인하여 정비모드를 유발하는 경우에 잠재적 고장 시간까지 포함한 종합 이용불능도로 구분하였다. 분석 결과로서 영광1호기 EDG의 유효 신뢰도는 0.995, 2호기는 1.0으로 매우 높은 수준을 유지하고 있었으며, 이용불능도의 역인 이용가능도는 1호기 A계열 EDG는 0.978, B계열은 0.979, 2호기 A는 0.991, B는 0.976으로 높은 수준이었다. 3,4호기 EDG의 유효 신뢰도는 1,2호기와 마찬가지로 높은 수준이었으나, 전체 신뢰도는 텐덤형 디젤엔진이 갖는 근본적 부하불균형 문제 때문에 낮은 수준이었다. 따라서, 영광3,4호기 EDG의 신뢰도를 높이기 위해 많은 노력을 기울였으며, 이를 통해 EDG 신뢰도 개선에 도움이 된 것으로 분석되었다.

• Proceedings of the Acoustical Society of Korea Conference
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• 1996.06a
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• pp.64-68
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• 1996

수중음파전달 모델은 benchmark 시험을 통해 정확도, 적용범위, 계산시간 등의 성능을 평가받는다. 본 논문에서는 analytic 모델, 정상 모드 모델(normal mode model), 포물선 방정식 모델(parabolic equation model), 가우시안 빔 모델(Gaussian beam model), 스펙트럼 모델(spectral model) 등 거리의존 모델에 대해 benchmark 시험을 수행하였으며, benchmark 시험은 다음과 같은 세 가지 거리의존 해양환경으로 나누어 실시했다 : 1) 해수면과 해저면이 Dirichlet 경계조건인 이상 쐐기 문제(ideal wedge problem), 2) 해수면은 앞서 말한 Dirichlet 경계조건이나 해저면은 전달 손실이 있는 손실 통과 해저면 쐐기 문제(penetrable lossy bottom wedge problem), 3) 해수면은 앞서 말한 Dirichlet 경계조건이고 해저면은 Neumann 경계조건으로 서로 평행이면 음파전달 속도가 거리방향 의존인 경우, 경우 1은 anaytic 모델을 사용하고 경우 2는 정상 모드 모델, 포물선 방정식 모델, 스펙트럼 모델을 사용하였으며, 경우 3에 대해서는 가우시안 빔 모델과 포물선 방정식 모델을 사용하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.7
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• pp.875-880
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• 2007

Scientific challenges in the field of MR(magnetorheological) fluids and devices consist in the development of MR devices, the mathematical modeling and simulation of MR devices, and the development of (optimal) control algorithm for MR device systems. To take a maximum advantage of MR fluids in control applications a reliable mathematical model, which predicts their nonlinear characteristics, is needed. A inverse model of the MR device is required to calculate current(or voltage) input of MR damper, which generates required damping force. In this paper, we implemented test a bench for shear mode rotary MR damper and laboratory tests were performed to study the characteristics of the prototype shear-mode rotary MR damper. The direct identification and inverse dynamics modeling for shear mode rotary MR dampers using multi-layer neural networks are studied.

• The Journal of the Acoustical Society of Korea
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• v.37 no.4
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• pp.233-241
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• 2018

In this paper, we develop a durability test method that can verify the noise caused by the repeated load on the door trim grip handle. The test method was developed in consideration of the load mode and durability test cycle applied to the grip handle. In order to verify the validity of the method, we demonstrated the door trim grip handle noise that occurred in the field claim with the product in the early stage of mass production through the developed test method. Finally, It is used to detect and improve the noise of subsequent development products through the currently developed test method.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1994-1996
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• 2004

본 논문에서는 배전반 또는 분전반에서 널리 이용되고 있는 1000 V 이하의 배선용 차단기, 즉 MCCB(Molded Case Circuit Breakers)의 신뢰성을 평가하기 위한 시험계획 및 시험방법을 검토하기 위한 전단계에서 반드시 필요한 고장모드영향분석(FMEA)의 결과를 서술하고, 또한 고장모드별로 대응되는 스트레스를 이용한 신뢰성평가 방안에 대해서 제시한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.7
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• pp.1156-1165
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• 1997

Complex modal testing is employed for the in-situ parameter identification of a four-axis active magnetic bearing system while the system is in operation. In the test, magnetic bearings are used as exciters as well as actuators for feedback control. The experimental results show that the directional frequency response function, which is properly defined in the complex domain, is a powerful tool for identification of bearing as well as modal parameters. It is also shown that the position and current stiffnesses can be accurately estimated using the relations between the measured forces, displacements, and currents.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.432-435
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• 2010

네트워크 기기분야에서는 정보통신기기 및 고속 멀티미디어 데이터 수요의 증가에 따라 네트워크 기기의 전력소비가 꾸준히 증가하고 있다. 특히 홈 네트워크 기기들은 전원이 연결되어 있는 상태로 동작하여 데이터 통신이 발생하지 않는 상황에서도 일정한 전력소모가 발생하므로 이에 대한 대처기술이 마련되어야 한다. 본 논문에서 대기전력 지원 홈게이트웨이 시스템 구현을 위하여 하드웨어를 설계하고 저전력 대기모드 지원 네트워크 프로토콜 인터페이스 개발하였으며 홈게이트웨이 시뮬레이터 S/W를 개발하여 홈게이트웨이의 기능을 시험테스트 하였다. 시뮬레이터 시험결과 각 네트워크 포트에서 발생된 트래픽에 따라 홈게이트웨이의 전원 모드가 변경됨을 확인할 수 있었으며 대기모드 시 소모 전력이 1W 미안으로 측정되었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.56-65
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• 2019

Recently, automobiles have been developed for safety and environmental reasons. Particularly, awareness of automobile safety is changing significantly. As a result, safety systems developed by ADAS have emerged. However, the period of mass production through ADAS development and test evaluation is long. Therefore, in this paper, we develop a brake dynamometer to shorten the time required for ADAS development and test evaluation. In addition, the developed brake dynamometer satisfies the international standard JIS D-0210, and the user can evaluate the braking force by selecting test conditions and test method for each mode of ADAS. We use the ACC, LKAS, and AEB scenarios proposed in previous studies to verify the reliability of the developed brake dynamometer. The developed brake dynamometer was verified by comparing the test values and the calculated values using theoretical formulas of the proposed ADAS mode based on previous studies. In addition, it is expected that the performance evaluation of brake parts for each ADAS mode will be possible in an environment where the vehicle test of ADAS is not possible in the future.