• 전력전자학회논문지
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• 제12권1호
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• pp.37-49
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• 2007

계통연계형 PV 시스템의 중요한 보호기능인 단독운전 검출기능은 시스템의 안전성 및 전기적 안정성 측면에서 매우 중요하다. 단독운전 검출기법으로는 크게 수동적 방식과 능동적 방식으로 분류되는 다양한 기법들이 있다. 본 연구에서는 IEEE 929-2000에서 제시하는 단독운전 시험조건 하에서 현재 널리 사용되는 능동적 방식 중 무효전력 변동 방식(RPV method)과 능동적 주파수 변동 방식(AFD method)을 채용한 시스템의 연계점에서 주파수 변동 특성을 해석하였다. 그리고 해석결과를 바탕으로 RPV 방식 및 AFD 방식의 설계법을 제시하였다. EMTP를 이용한 시스템 시뮬레이션을 통하여 제안된 해석 및 설계법의 타당성 및 유효성을 검증하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.135-140
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• 1992

This paper presents the configuration, HILS procedure and performance simulation results of the RPV autopilot including a strapdown AHRS. Real time hardware-in-the-loop simulation was performed by using a 3 axis flight motion simulator alonged assumed flight trajectory of the RPV. Being compared with the result of the 6 DOF simulation, the HILS results showed that the performance of the autopilot was satisfactory.

• Nuclear Engineering and Technology
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• 제34권6호
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• pp.574-585
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• 2002

The microstructural characteristics and its related mechanical properties of RPV cladding have been investigated using small punch (SP) tests. SA508 Cl.3 RPV steel plates were overlay cladded with the type ER309L welding consumables by submerged arc welding process. Although the RPV clad material had a small portion of 5 ferrite phase, it still showed the ductile to brittle transition behavior The transition temperature was determined by the SP test and it depended on the content of $\sigma$ phase, specimen size, and determination methods. The fracture appearance of SP specimen was changed from circumferential to radial cracking as test temperature became low, and below the transition temperature region, ER309L cladding usually fractured along the 6 ferrite by the low temperature failure of ferrite phase.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 추계학술대회 논문집
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• pp.64-67
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• 2008

To detect islanding mode when the grid is being tripped is a major safety issue in the Utility Interactive Distributed Generation (UIDG) system. In this paper, analytical design method is suggested for AFD & RPV method under IEEE929-2000 recommended islanding test condition. We have discussed that there is a same point. we injected reactive component of the current by AFD & RPV methods, but the current reference generated is other waveform. Possible if amount of reactive components in this methods are same each method, there is happened same rates frequency variation. To verify the validity of the analytical comparison, this paper presents simulation and experimental results from single phase, 3[kW] inverter for the transformerless UIDG system.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2610-2615
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• 2021

The prediction of irradiation-induced transition temperature shift for RPV steels is an important method for long term operation of nuclear power plant. Based on the irradiation embrittlement data, an irradiation-induced transition temperature shift prediction model is developed with machine learning method XGBoost. Then the residual, standard deviation and predicted value vs. measured value analysis are conducted to analyze the accuracy of this model. At last, Cu content threshold and saturation values analysis, temperature dependence, Ni/Cu dependence and flux effect are given to verify the reliability. Those results show that the prediction model developed with XGBoost has high accuracy for predicting the irradiation embrittlement trend of RPV steel. The prediction results are consistent with the current understanding of RPV embrittlement mechanism.

• Journal of Plant Biology
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• 제6권2호
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• pp.9-21
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• 1963

A mosaic diseased radish collected from the suburb of Seoul, in November, 1961 was used for studing the host range, physical properteis, purificaitiion, insect transmission, and electron microscopy. A Japanese strain of radish mosaic(RPV) was also used with Korean strain of radish mosaic (KRMV) for a comparative study. The two viruses, KRMA and RPV, were identified by the difference in host range, insect transmission and electron microscopy. The KRMA was severely infective on tobacco and Nicotiana glutinosa, while on Gomphrena globsa was immune to the virus. RPV produces necrotic local lesions on Gomphrena globosa but did not infect tobacco and N. glutinosa. Among varieties of radish, Seoul, Akamaroo, Akanagea, Koong-Joong showed more severe symptoms than Simoo, Minong, Paek-soo, which appeared to be fainly resistant. In a number of tests, it was found that the virus KRMA retained its infectivity until to a dilution of 1:2,000, heating at $58^{\circ}$ for 10 minutes, adn aging in vitro for 7 days at room temperature. The RPV was not inactivated until it was diluted to 1:2,000, heated to $56^{\circ}$, and aged for 6 days. The KRMV was readily transmitted by the aphid(Myzus persicae Sulz). The virus RPV was not transmitted by the aphid in a number of tests. Partialy purified viruses using ammonium acetate buffer, salting-out by ammonium sulfate and centrifugation of high and low speed were highly infective. Electron micrographs showed that the KRMV paticles are of spherical particles whereas the RPV particles are rod-shaped.

• Journal of Plant Biology
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• 제6권2호
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• pp.7-7
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• 1963

A mosaic diseased radish collected from the suburb of Seoul, in November, 1961 was used for studing the host range, physical properteis, purificaitiion, insect transmission, and electron microscopy. A Japanese strain of radish mosaic(RPV) was also used with Korean strain of radish mosaic (KRMV) for a comparative study. The two viruses, KRMA and RPV, were identified by the difference in host range, insect transmission and electron microscopy. The KRMA was severely infective on tobacco and Nicotiana glutinosa, while on Gomphrena globsa was immune to the virus. RPV produces necrotic local lesions on Gomphrena globosa but did not infect tobacco and N. glutinosa. Among varieties of radish, Seoul, Akamaroo, Akanagea, Koong-Joong showed more severe symptoms than Simoo, Minong, Paek-soo, which appeared to be fainly resistant. In a number of tests, it was found that the virus KRMA retained its infectivity until to a dilution of 1:2,000, heating at $58^{\circ}$ for 10 minutes, adn aging in vitro for 7 days at room temperature. The RPV was not inactivated until it was diluted to 1:2,000, heated to $56^{\circ}$, and aged for 6 days. The KRMV was readily transmitted by the aphid(Myzus persicae Sulz). The virus RPV was not transmitted by the aphid in a number of tests. Partialy purified viruses using ammonium acetate buffer, salting-out by ammonium sulfate and centrifugation of high and low speed were highly infective. Electron micrographs showed that the KRMV paticles are of spherical particles whereas the RPV particles are rod-shaped.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.3112-3121
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• 2021

One of the major factors affecting the life span of a Reactor Pressure Vessel (RPV) is the Pressurised Thermal Shock (PTS). PTS is a thermo-mechanical load on the RPV wall due to steep temperature gradients and structural load created by internal pressure of the fluid within the RPV. Safe operating life of a nuclear power plant is ensured by carrying out fracture analysis of the RPV against thermal shock. Carrying out fracture tests on RPV/large scale components is not always feasible. Hence, studies on laboratory level specimens are necessary to validate and supplement the prototype results. This paper aims to study the fracture behaviour of standard Compact Tension [C(T)] specimens, made of RPV steel 20MnMoNi55, subjected to thermal shock through experimental and numerical investigations. Fracture tests have been carried out on the C(T) specimens subjected to thermal transient load and tensile load to quantify the effect of thermal shock. Crack resistance curves are obtained from the fracture tests as per ASTM E1820 and compared with those obtained numerically using XFEM and a good agreement was found. A quantitative study on the crack tip plastic zone, computed using cohesive segment approach, from the numerical analyses justified the experimental crack initiation toughness.

• 한국식품저장유통학회지
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• 제30권3호
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• pp.514-525
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• 2023

본 연구는 매실식초 및 홍삼농축액 혼합 음료의 증진된 피로회복 효과를 확인하고자 유기산 함량과 고강도 운동 쥐모델에서 항피로 관련 인자를 측정하였다. 홍삼농축액 및 매실식초 혼합 음료 내 유기산 함량은 acetic acid가 1,654.17 ppm으로 가장 높은 함량을 보였고, malic acid와 citric acid가 각각 617.28, 600.12 ppm으로 확인되었다. 항피로 관련 인자 중 지구력을 측정한 결과, 홍삼매실식초 혼합음료(RPV)를 섭취한 군에서 138.83 min으로 가장 높은 지구력을 보였으며, 혈중 무기인산과 암모니아 및 젖산 함량은 0.67 mM, 24.28 mmol/L 및 1.75 mM으로 유의적으로 가장 낮은 수치를 보였다. 또한, 간 및 근육 내 글리코겐 함량에서 RPV는 각각 288.4, 22.84 ㎍/g으로 가장 높은 함량을 나타냈다. RPV의 혈청 및 근육조직 내 creatine kinase 함량은 465.42와 33.05 U/L로 유의적으로 가장 낮은 값으로 확인되었으며, 근육 내 lactate dehydrogenase 함량은 RPV에서 가장 높은 값인 140.13 U/L로 나타났다. 본 연구결과를 통해 풍부한 유기산을 가진 매실식초 및 홍삼농축액 혼합 음료의 섭취는 매실식초 또는 홍삼농축액의 단일 섭취에 비해 증진된 항피로 효과를 나타낸다는 것을 확인하였으며, 이는 피로회복 기능성식품 소재로 이용할 수 있을 것으로 기대한다.

• 방사성폐기물학회지
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• 제2권1호
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• pp.69-75
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• 2004

고리 1호기 원자로압력용기의 중성자속과 방사화생성물 재고량을 계산하기 위하여 DORT 코드와 ORIGEN2 코드를 사용하였다. DORT 코드를 이용해 중성자속을 계산하기 위하여 노심을 중앙부터 원자로압력용기까지 방위각 방향으로 94 mesh로 분할하였다. 원자로압력용기 영역의 중성자속을 이용하여 주요 핵종의 단면적을 재계산하였다. 원자로압력용기의 경우, $^{55}$Fe, $^{60}$Co, $^{59}$ Ni 및 $^{63}$ Ni의 핵종이 총 방사능의 약 95%를 차지하였으며, 해체 후 50년 이상 냉각후의 총 방사능은 정지시점과 비교하여 약 0.2% 이하로 감소하는 것으로 평가되었다. 총 중량이 210 ton인 원자로압력용기의 총 방사능은 5.25${\times}$$10^{6}$GBq이었다. ORIGEN2 계산 결과를 검증하기 위하여 고리 1호기 원자로압력용기의 계산값과 실측값에 대한 비교 검증을 수행하였으며, 그 결과는 서로 일치함을 확인할 수 있었다.