• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.217-222
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• 1995

1994년 11월에 나타난 고리 1호기 증기발생기의 전열관 누설에 대한 원인 조사결과, 손상원인은 2차측 응력부식균열(ODSCC)로 밝혀졌으므로, 이에 따른 단기적인 손상완화대책으로 (1) TiO$_2$와 보론산을 첨가한 틈새 세정, (2) TiO$_2$를 첨가한 하이드라진 담금, (3) $Na^{+}$/Cl$^{-}$ 몰비 조절, (4) 용존산소 제거, (5) T$_{HOT}$ 감소 등을 선정하였다. 이와 같은 완화 대책을 적용한 경우의 ODSCC 손상진전율을 확률론적으로 분석한 결과, 증기발생기교체(1998년 예정) 이전까지 전열관 누설에 의한 운전정지 가능성은 매우 낮게 나타났다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.747-752
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• 1997

고리 3,4호기 및 영광 1,2호기 PSA Ⅰ단계 수행 결과 ATWT에 대한 노심 손상 확률은 다른 사건에 비해 상대적으로 적어 소홀히 취급될 수 있으나 전체적인 노심 손상 확률 저감을 위해 본 연구에서는 ATWT 사건 중 터빈 정지시 원자로 정지불능을 선정하여 HRA를 수행하였다. HRA 수행의 첫째 과정은 위에서 선정한 사건에 대해 시나리오를 가정하고 이를 4개 그룹의 주제어실 운전원들에게 적용하여 모의 제어반을 이용한 훈련을 실시하였으며 운전원 조치 과정중의 행동관찰, 훈련결과, 개별 면담 등을 통해 국내 운전원 특성에 맞는 HRA의 기초자료를 얻었다. 두 번째 과정은 위의 결과 및 절차서에 근거하여 PSF 고려 유무에 따라 실패 확률의 정량적 평가와 불확실성 분석을 수행하여 ATWT에 대한 HRA 수행 자료로 활용 가능하도록 하였으며, 끝으로 ATWT 영향 완화를 위한 대안을 제시함으로서 노심 손상 확률을 감소시키기 위한 기초가 되도록 하였다.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.1
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• pp.69-72
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• 2021

한전에서 운영중인 요르단 알카트라나발전소에서 발전기 고정자권선 전계완화 절연물의 손상되었다. Overlap 부위의 정비를 수행한 결과를 분석하였고, 손상원인을 규명하여 불시정지로 인한 손실을 최소화하기 위한 단기대책과 장기적인 대책을 제시하였다.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.831-837
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• 1999

Ochratoxin A (OA), a naturally occurring mycotoxin, has been known to cause renal and hepatic lesion in human and animals. This study was carried out to investigate the modulation effects of antioxidant vitamins on OA-induced lipid peroxidation associated with oxidative damage. Vitamin C (10 mg/kg/day) and vitamin E (63.8 mg/kg/day) were administered by intraperitoneal (i.p.) injection to male ICR mice, and 1 hr later, OA which was dissolved in 0.1 M $NaHCO_3$, treated 4 mg/kg/day by i.p. injection. During 4 days repeated, and then measured superoxide dismutase (SOD) activity, catalase activity and malondialdehyde (MDA) formation in microsomes of liver and kidney. Additionally, the relationship between cell damage and modulation effects of antioxidant vitamins was evaluated by comet assay. Results were as followed; i) SOD, catalase activity and MDA level were significantly increased by OA treated, ii) SOD, catalase activity and MDA formation were significantly decreased by antioxidant vitamins combine treated, iii) blood cell damage associated with lipid peroxidation, induced by OA, also modulated by antioxidant vitamins. These results indicated that antioxidant vitamins might be used for prevention of renal and hepatic damage due to ochratoxicosis.

• Journal of Industrial Convergence
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• v.21 no.2
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• pp.25-32
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• 2023

Constipation is the most common digestive disorder, and it occurs frequently in the early stages and affects the prognosis on rehabilitation stage in the patients with brain injury. The purpose of this study is to evaluate the bowel habits of brain-injured patients undergoing enteral nutrition immediately after admission to rehabilitation and transmission, and to investigate the effects of abdominal massage and lower extremity exercise. The study design is a quasi-experimental study to investigate the effect of a bowel care intervention (abdominal massage and lower extremity exercise) applicable to patients with brain lesions. As a result of the study, the number of bowel movements was significantly higher in the intervention group (p=.030), and the use of suppositories in the control group was statistically significantly higher than that in the intervention group (p=.004). The time of constipation relief was 1.73 days for the experimental group and 4.61 days for the control group, indicating that there was a difference in the time of constipation relief between the two groups (p<.001). Abdominal massage and lower extremity exercise were effective as nursing interventions to relieve constipation and prevent constipation in patients with brain injury from the early stage of rehabilitation.

• 한국체육학회지인문사회과학편
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• v.58 no.2
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• pp.405-416
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• 2019

This study aimed to identify the efficiency of short track-related sports injury prevention program consisted of muscle strength and neuromuscular training on non-contact injury incidence and characteristics in knee and ankle joints and low back for elite short track speed skaters. Twenty-five short track athletes who belonged to G-City Team were participated in this study from Nov. 2017 to Jul. 2018. Information on their sports injuries occurred were collected and injury prevention program was applied in their warm-up every training sessions and competition. Also their symptom-level of knee and ankle joint and low back were measured by using OSTRC overuse injury questionnaire and Cumberland ankle instability(CAIT). The injury incidence rate after application of prevention program was 2.79 injuries/1,000 hour exposures(HEs), which was lower than before (3.04 injuries/1,000HEs). The OSTRC score (30.89±28.34 and 23.84±23.61, respectively) in knee and low back after application of prevention program were lower than before (58.47±26.77 and 52.36±21.55, respectively), and the CAIT score (13.47±6.07) in ankle joint after application of program was higher than before (16.26±7.28), which means that their symptom-level was alleviated with sports injury prevention program. In conclusion, the sports injury prevention program designed for short track's motion and characteristic can have positive influences on the occurrence of non-contact injury for short track speed skaters.

• Journal of agriculture & life science
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• v.50 no.3
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• pp.129-139
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• 2016

Curcumin plays a protective role in brain injury through its anti-oxidant and anti-inflammatory activities. Moreover, peroxiredoxin-5 exerts a protective effect against oxidative stress. The aim of this study was to investigate whether curcumin modulated the peroxiredoxin-5 expression in focal cerebral ischemic animal model. Middle cerebral artery occlusion(MCAO) was performed to induce cerebral ischemic injury in rats. Adult male rats were injected intraperitoneally with vehicle or curcumin(50mg/kg B.W.) 1 h after MCAO and cerebral cortex tissues were collected 24 h after MCAO. Photographs of hematoxylin and eosin staining showed that MCAO induced necrotic changes with scalloped shrunken form and apoptotic changes with nuclear chromatin condensations. However, curcumin treatment attenuated MCAO-induced histopathological changes. Moreover, this study clearly showed that peroxiredoxin-5 expression was decreased in MCAO operated animal with vehicle using a proteomics approach. However, this decrease in peroxiredoxin-5 expression was attenuated by curcumin treatment. Reverse-transcription PCR and Western blot analyses confirmed that curcumin treatment alleviated the MCAO injury-induced decrease in peroxiredoxin-5 expression(p<0.05). These results demonstrated that curcumin regulates peroxiredoxin-5 expression in MCAO animal model. In conclusion, our findings suggest that curcumin exerts a neuroprotective effect in cerebral ischemia by attenuating the MCAO-induced decrease in peroxiredoxin-5 expression.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.28 no.4
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• pp.41-50
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• 2015

Objectives : 선태는 아토피 피부염에서 소양증 완화를 위해 사용되고 있다. 본 연구에서는 면역계 및 신경계 손상을 일으킨 rat model에서 선태 추출물이 소양증 완화에 효과가 있는지 알아보고자 한다.Methods : 출생 48시간 이내의 rat을 대상으로, capsaicin(50 mg/kg)을 피하 투여하였다. 임의로 선정된 12마리의 실험군에 3주 동안 선태 추출물(0.5g/kg)을 매일 경구 투여하였다. 이후 scratching behavior 와 dermatitis score를 측정하였다.Results : 선태 투여군과 대조군에서 scratching number 와 dermatitis score의 차이가 없었다.Conclusions : 위의 결과로부터 capsaicin으로 유발한 아토피 피부염 rat model에서 선태의 소양증 완화 효과가 없다는 것을 알 수 있었다. 아토피 피부염의 효과적인 치료를 위해 면역계 뿐만 아니라 신경계 손상 회복시키는 약물을 찾기 위한 더 많은 연구가 필요할 것으로 생각된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.7
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• pp.555-563
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• 2012

In earth orbit, a great number of orbital debris move around in extremely high velocity, and they become serious threats to satellites. In this study, smoothed particle hydrodynamics(SPH) is used to analyze the damage of a low earth orbit satellite due to the hypervelocity impact with orbital debris. The damage of honeycomb sandwich panel(HC/SP) used for walls of a satellite is analyzed with respect to impact velocities. For the additional analysis to examine the safety of interior components of the satellite, an attached electronic box and an offset electronic box are considered. As a result of the analysis considering the orbital debris having a probability of collision more than 2% at altitude of 685km, it is shown that the HC/SP can be perforated but only small craters are formed on both the attached electronic box and the offset electronic box.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.4
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• pp.233-242
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• 2023

The unscented Kalman filter (UKF), which is widely used to estimate the states of nonlinear dynamic systems, can be improved to realize robust system identification by using multiple sigma-point sets. When using Kalman filter methods for system identification, artificial noises must be appropriately selected to achieve optimal estimation performance. Additionally, an appropriate scaling factor for the sigma-points must be selected to capture the nonlinearity of the state-space model. This study entailed the use of Bouc-Wen hysteresis model to examine the nonlinear behavior of a single-degree-of-freedom oscillator. On the basis of the effects of the selected artificial noises and scaling factor, a new UKF method using multiple sigma-point sets was devised for improved robustness of the estimation over various signal-to-noise-ratio values. The results demonstrate that the proposed method can accurately track nonlinear system states even when the measurement noise levels are high, while being robust to the selection of artificial noise levels.