• 한국전자파학회논문지
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• 제8권1호
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• pp.83-93
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• 1997

본 논문은 고전압 실험실에서 시변성 전자계의 측정 및 평가에 관한 것으로 전자적 외란은 주로 전력장비의 지락고장 및 개폐조작에 의해 기인되며, 전자회로와 제어장비틀은 전자방해작용에 매우 민감하다. 주어진 전자환 경에 대한 전자방해작용의 레벨을 평가하는 것은 필수적이다. 전계는 40 Hz-2oo MHz 범위의 대역폭을 갖는 전계센서로 관측되었으며, 시변성 자계는 출력이 입사신호에 직접적으로 비례하는 루프형 센서로 측정되었다. 또한 진동성 과도전류와 차단파 임펄스전압에 의해 유도된 전자방해작용의 레벨파 전자 차폐의 외함설계에 관한 정보를 주는 사변성 전자계의 주파수 성분을 고속프리에변환으로 분석하였다.

• Journal of Radiation Protection and Research
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• 제10권2호
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• pp.148-154
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• 1985

KSC-1 핵연료 수송용기에 대한 방사선차폐해석을 QAD-CG, ANISN-KA, DOT 3.5등의 전산코드와 DLC-23/CASK의 핵단면적 자료를 사용하여 수행하였다. 운반물인 사용후 핵연료집합체로 부터 방출되는 중성자 및 감마선의 방사선원항은 ORIGEN-79 전산코드를 이용하여 평가하였다. 방사선차폐해석 결과, 1개의 가압경수로 사용후 핵연료집합체를 운반할 수 있는 KSC-1 핵연료수송용기는 정상적인 수송조건에서 뿐만 아니라 가상적인 사고수송조건하에서도 관련 법령에서 정하는 기준을 만족하고 있어 방사선차폐해석의 관점에서 볼 때, 그 안전성이 입증된다.

• Nuclear Engineering and Technology
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• 제25권1호
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• pp.80-90
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• 1993

원자력발전소에는 방사선 차폐체를 통한 수 많은 관통부들이 존재하며. 이를 통한 방사선 스트리밍의 해석은 발전소 작업자들의 방호를 위한 차폐 설계에 있어 중요한 고려사항 중 하나이다. 본 연구에서는 관통부 중 주종을 이루는 콘크리트 벽체 내 원통형 직관통부로 단방향. 단일 에너지의 감마선 면선원에 의한 방사선 스트리밍 해석을 위하여 몬테칼로방법에 따른 전산 프로그램을 개발하였으며, 이를 사용하여 여러 경우의 감마선원 에너지와 입사각. 관통부의 반경과 길이에 대하여 관통부 출구에서의 평균 선량을 계산하여 그 결과를 라이브러리화 하였다 또한. 이를 이용하여 등방향 점선원에 대하여 적절히 근사할 수 있음을 보임으로서 임의의 감마선원 분포에 대하여 짧은 전산시 간으로 정확한 결과를 구할 수 있는 방법을 제공하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.208-211
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• 2005

This paper presents an ultra-low partial discharge(PD) measurement system that has been accepted as a non-destructive method to estimate electrical insulation of low-voltage electric devices. The PD measurement system is composed of a coupling network, a low noise amplifier, and associated electronics. A shielding box is used to make a better condition against electromagnetic interference. A low cut-off frequency of the coupling network was 1MHz(-3 dB). Calibration tests on laboratory set-up have shown that the PD measurement system has a stable sensitivity of 11.4mV/pC. In an application experiment on a low-voltage induction motor(5HP), we could detect 0.77pC level of partial discharge pulse at the applied voltage of AC 664 V$_{peak}$.

• 조명전기설비학회논문지
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• 제12권4호
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• pp.146-154
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• 1998

교류 전원선로에서 발생하는 수 kHz에서 수십 MHz에 이르는 광대역의 주파수특성올 가진 전원노이즈는 전기, 전자장비의 정상적인 동작에 많은 장해요소가 되고 있으며 이들 전도노이즈를 억제하기 위한 부품으로 현재 써어지 억제부품과 필터가 적용되고 있다. 그러나 기존의 대책부품은 전력공급선과 노이즈 피해회로를 전기적으로 완전히 절연시킬 수 없기 때문에 전도 노이즈 중에서 가장 크게 발생하는 공통모드 노이즈 억제성능이 제한 되고 있다. 본 논문에서는 절연변압기의 절연 특성에 정전 차폐를 추가함으로써 전도노이즈 및 써어지 억제기능이 우수한 NCf의 설계방법올 제시하였으며, 설계 제작된 1[kVA] NCT 시작품의 모의 등가회로에 대한 써어지 해석결과와 실험 측정 결과를 상호 비교하여 제안된 모델의 특성을 비교 평가하였다.

• Journal of Welding and Joining
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• 제30권4호
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• pp.38-43
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• 2012

Using a fiber laser heat source, an oil pressure sensor was fabricated to measure the pressure in commercial vehicles. A stepping motor was used for the rotational and translational motion in the diaphragms and hardware joining. Laser welding process algorism including shielding gas control and vision system was integrated by using LabVIEW software for the high quality welding and in-line monitoring purpose. For the maximum flexibility in pressure transmission to the pressure sensor, thin sheet metal diaphragm, $25{\sim}50{\mu}m$(SUS-316L), was used and the diaphragms were optimally designed with FEM analysis. The welded samples were cross-sectioned the observation showed that the maximum depth ratio was more than seven times of diaphragms. The maximum welding speed was measured to be as high as 50in/mm by the developed automation mechanism. The fabricated prototypes were tested for the proof pressure, spring constant and sealing. The FEM results of spring constant measurement was as accurate as up to 80% of the design value and the sensor was safely operated up to the nominal pressure of 10bars.

• Journal of Welding and Joining
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• 제28권5호
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• pp.86-92
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• 2010

In GMAW processes, bead geometry is a criterion to estimate welding quality. Bead geometry is affected by welding current, arc voltage, welding speed, shielding gas and so on. Thus the welding condition has to be selected carefully. In this paper, an experimental method for the selection of optimal welding condition was proposed in the root pass welding which was done along the GMA V-grooved butt weld joint. This method uses the response surface analysis in which the width and height of back bead were chosen as the quality variables of the weld. The overall desirability function, which is the combined desirability function for the two quality variables, was used as the objective function for getting the optimal welding condition. Through the experiments, the target values of the back bead width and the height were chosen as 4mm and 1mm respectively for the V-grooved butt weld joint. From a series of welding test, it was revealed that a uniform weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.

• 한국컴퓨터정보학회논문지
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• 제24권8호
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• pp.37-43
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• 2019

The existing smart farm technology has been systematized for the mass production rather than the consumer. There are many problems such as economical aspect to apply to actual rural environment due to aging. The purpose of this study is to apply smart farm technology based on the applicability of population aged in rural areas. Due to the heat wave, the crops in general greenhouse cultivation facilities suffered from damage such as sunlight damage. To minimize such damage, adjust the temperature and humidity environment or install a light-shielding film. However, the workers in the rural areas are aging and the elderly who are farming alone have a lot of difficulties in doing so. In the case of people with weak physical strength, there is a danger that they may lead to safety accidents when carrying heavy loads. In this paper, we propose 'Smart Palm capable of automatic transportation function', applying small smart vehicles that follow workers to existing smart farms to improve and prevent these problems. It is a smart farm that performs the control functions of the existing smart greenhouse environment, installs the rail for each trough, and has a vehicle that follows the worker. The smart app can directly control the greenhouse and the vehicle remotely manually.

• 소성∙가공
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• 제30권1호
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• pp.35-42
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• 2021

Magnesium alloys are used in electronic devices such as laptops due to their lightweight features as well as vibration absorption and electromagnetic shielding properties. However, the precision of electronics is limited by the large number of small and precise ribs, the cost-effective manufacture of which requires appropriate technology. Plate forging is an efficient manufacturing process that can address these challenges. In this study, plate forging of magnesium alloys was investigated specifically for the fabrication of laptop cover. The plate forging process with back-pressure was used for near-net shape formation. Finite element analysis was used to select appropriate variables for back-pressure formation to generate ribs of various sizes and shapes without defects. The reliability of the analysis was verified to manufacture the prototype. The effect of back-pressure can be verified via fabrication of prototypes as well as structure and forming analysis based on finite element method. The process design factor of back-pressure increases formability without defects of under-filling and flow-through. Moreover, the tensile strength was maintained even after high temperature plate forging at 370 ℃, and the elongation was improved.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.1009-1014
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• 2023

Muon tomography is a useful method for monitoring special nuclear materials (SNMs) such as spent nuclear fuel inside dry cask storage. Multiple Coulomb scattering of muons can be used to provide information about the 3-dimensional structure and atomic number(Z) of the inner materials. Tomography using muons is less affected by the shielding material and less harmful to health than other measurement methods. We developed a muon detector for muon tomography, which consists of a plastic scintillator, 64 long wavelength-shifting (WLS) fibers attached to the top of the plastic scintillator, and silicon photomultipliers (SiPMs) connected to both ends of each WLS fiber. The muon detector can acquire X and Y positions simultaneously using a position determination algorithm. The design parameters of the muon detector were optimized using DETECT2000 and Geant4 simulations, and a muon detector prototype was built based on the results. Spatial resolution measurement was performed using simulations and experiments to evaluate the feasibility of the muon detector. The experimental results were in good agreement with the simulation results. The muon detector has been confirmed for use in a muon tomography system.