• 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 Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.111-118
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• 2006

The Emergency Diesel Generator(EDG) is a very important piece of equipment for the safety of a Nuclear Power Plant(NPP). In this study, the operating vibration or three kinds or EDG system was measured. The target EDG systems art Yonggwang 5 unit, Ulchin 2 unit and Ulchin 3 unit. The Yonggwang 5 and Ulchin 3 unit EDG system is the same type but the foundation systems are different. One is an anchor bolt type and the other is a spring and viscous-damper type. The purpose of this measurement is for a verification of the vibration isolation effect according to the foundation system. As a result. it can he said that the spring and viscous damper system of the EDG performed well for the vibration isolation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.217-222
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• 2007

An Emergency Diesel Generator (EDG) is one of the safety related equipments of a Nuclear Power Plant. The seismic capacity of an EDG in nuclear power plants influences the seismic safety of the plants significantly. A recent study showed that the increase of the seismic capacity of the EDG could reduce the core damage frequency (CDF) remarkably. It is known that the major failure mode of the EDG is a concrete coning failure due to a pulling out of the anchor bolts. The use of base isolators instead of anchor bolts can increase the seismic capacity of the EDG without any major problems. This study introduces a seismic risk analysis method and presents sample results about the seismically isolated and conventional EDG system.

• Journal of Korean Society for Quality Management
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• v.26 no.4
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• pp.265-276
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• 1998

A commercial nuclear power station contains at least two emergency diesel generators(EDG) to control the risk of severe core damage during station blackout accidnets. Therefore, thereliability of the EDG's to start and load-run on demand must be maintained at a sufficiently high level. Until now, a simple assessment of start and load-run success rates was used to calculate the EDG reliability. However, this method has been found to contain many defects. Recently, the work of Martz et al.(1996) proposed the use of the Bayes estimator to find EDG reliability. Shim(1996) proposed a confidence interval for the Bayes estimator, compare the above two methods. In this paper, we introduce the notion of "Composite Reliablility" to estimate the reliability of nuclear-power plant EDG, and using practical examples, illustrate which method is more a, pp.opriate in our situation.situation.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.776-782
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• 2012

Marbling (intramuscular fat) is the most economically important meat quality trait in Hanwoo (Korean cattle). The endothelial differentiation G-protein coupled receptor 1 (EDG1) gene, involved in blood vessel formation, is located within the genomic region of a quantitative trait locus (QTL) for marbling on bovine chromosome 3. Thus, the EDG1 gene can be considered as a positional and functional candidate gene for meat quality in beef cattle. This study aimed to identify single nucleotide polymorphisms (SNPs) in the EDG1 gene and to evaluate their associations with carcass traits in Hanwoo population. We have sequenced a fragment of 5'-UTR of the EDG1 gene and identified one SNP. Genotyping of the g.166A>G SNP marker was carried out using PCR-RFLP analysis in 309 Hanwoo steers in order to evaluate their association with carcass traits. The g.166A>G SNP marker showed a significant effect on the marbling score. Animals with the GG genotype had higher marbling score compared with AA and AG genotypes (p<0.05). This SNP marker also showed a significant additive effects for the marbling score (p<0.05). These results suggest that the EDG1 gene can be used as a molecular marker for DNA marker-assisted selection in order to increase the levels of the marbling score in Hanwoo.

• Korean Journal of Agricultural Science
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• v.39 no.3
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• pp.349-355
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• 2012

Thyroglobulin (TG) gene was known to be regulated fat cell growth and differentiation and the endothelial differentiation sphingolipid G-protein-coupled receptor 1 (EDG1) gene involves blood vessel formation and known to be affecting carcass traits in beef cattle. The aim of this study was to identify the single nucleotide polymorphisms (SNPs) in both TG and EDG1 genes and to analyze the association with carcass traits in Korean cattle (Hanwoo). The T354C SNP in TG gene located at the 3' flanking region and c.-312A>G SNP located at 3'-UTR of EDG1 gene were used for genotyping the animals using PCR-RFLP method. Three genotypes were identified in T354C SNP in TG gene and only two AA and AG genotypes were observed for the c.-312A>G SNP in EDG1 gene. The results indicated that T354C SNP in TG gene was not significantly associated with carcass traits. However, the c.-312A>G SNP in EDG1 gene had significant effects on backfat thickness (BF) and yield index (YI). These results may provide valuable information for further candidate gene studies affecting carcass traits in Korean cattle and may use as marker assisted selection for improving the quality of meat in Hanwoo.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.6
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• pp.69-78
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• 2007

In this study, for the evaluation of seismic safety of the isolated Emergency Diesel Generator (EDG) System more quantitatively, the seismic fragility analysis method were proposed. Using the proposed method, seismic fragility analysis performed and a seismic risk of EDG system was present. The fragility analysis performed not for an existing EDG system but also for an isolated EDG system which increases the seismic capacity. At first, numerical models for existing and isolated EDG system were constructed and seismic response analysis performed according to input seismic waves and peak ground accelerations. An uncertainty factors and failure modes of both fixed and isolated EDG system were assumed for fragility analysis. The HCLPF values were evaluated for the compare the improvement effect using the isolation system. As a result, the isolation system can make better the seismic fragility of EDG system, but the failure of isolation system was govern the behavior of whole system.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.479-486
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• 2006

This paper presents tile results of experimental studies of the isolated Model EDG Systems. For the experimental work, the scaled model of EDG system and the isolation systems were developed. The target EDG model is 16PC2-5V400 which was manufactured by the SEMT Pielstick corporation. The Coil Spring and Viscous Damper Systems were selected for the isolation system. The Coil Spring and Viscous Damper systems can reduce not only seismic forces but also the operating vibration. For the input seismic motions, the scenario earthquake and the artificial earthquakes which were developed as NRC design spectrum and Uniform hazard Spectrum(UHS) were selected. As a result, at least 20% of seismic forces were decreased as the isolation system.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.419-424
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• 2011

Galla Rhois and its components are known to possess anti-infl ammatory properties. In the present study, we prepared equilibrium mixture of ethyl m-digallate and ethyl p-digallate isomers (EDG) from Galla Rhois and examined its effect on nitric oxide (NO) production in murine macrophage cell line. Treatment of RAW264.7 macrophages with EDG signifi cantly inhibited NO production and inducible nitric oxide synthase (iNOS) expression stimulated by LPS, as assessed by Western blot and quantitative RT-PCR analyses. We also demonstrated that EDG treatment led to an increase in heme oxygenase-1 (HO-1) mRNA and protein expression. EDG treatment also enhanced expression level of nuclear factor-erythroid 2-related factor 2 (Nrf2) in nucleus, which is critical for transcriptional induction of HO-1. Treatment with SnPP (tin protoporphyrin IX), a selective HO-1 inhibitor, reversed EDG-mediated inhibition of nitrite production, suggesting that HO-1 plays an important role in the suppression of NO production by EDG. Taken together, these results indicate that EDG isolated from Galla Rhois suppresses LPS-stimulated NO production in RAW 264.7 macrophages via HO-1 induction.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.2
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• pp.79-86
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• 2014

This paper describes an integrity evaluation method for emergency diesel generator(EDG) and rotor part of EDG. EDG is a very important equipment in the nuclear power plant(NPP). EDG supplies electricity to the safety-related equipments for the safety shut down of NPP in an emergency situation of earthquake. The safety of the rotor part of EDG is also important during seismic impact from earthquake. The finite element modelling of the EDG including rotor part was constructed. The modal analysis of EDG was firstly performed. The first natural frequency was calculated and revealed higher than the cutoff frequency of seismic spectrum. Then the stress analysis was done to compare with the allowable stress. The safety of the rotor part was investigated by the finite element analysis of the rotor and journal bearing interaction to find film thickness and critical speed. The seismic load was applied to rotor part in a manner that the load was a weighted static load. Analysis results showed that the maximum stress was within the range of allowable stress and the film thickness is larger than the permissible minimum thickness, and the critical speed was out of the operating speed. Hence, the structural and dynamic integrity of EDG could be confirmed by the numerical analysis method used in this paper. However, dynamic analysis of a rotating rotor and supporting bearing with the seismic impact needs to be investigated in a more rigorous method since the seismic load to the rotating part complicates the behavior of rotating system.