• 한국방사선학회논문지
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• 제15권4호
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• pp.415-427
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• 2021

한국원자력의학원에서는 50 MeV 사이클로트론의 빔 라인을 이용하여 연구자들에게 다양한 빔 조사 서비스를 수행하고 있다. 특히 중성자 빔 서비스는 양성자와 베릴륨의 핵반응을 이용하기 때문에 높은 전류를 사용하므로 조사 시료의 방사화 가능성이 높아진다. 본 연구에서는 연구자들이 선호하는 35 MeV 20 ㎂ 중성자 빔 서비스에 의해 발생 가능한 방사화에 대해 MCNP 6.2와 FISPACT-II 4.0을 이용해 평가했다. 평가결과 철, 구리, 텅스텐 시료는 1시간 이상 조사하는 경우 장반감기 핵종이 생성되는 방사화가 발생하여 자체처분농도를 초과했다. 매일 2시간 사용 조건에서 건축물에 대한 방사화는 발생하지 않았고 조사실 내부 공기의 방사화로 인한 종사자의 내부피폭은 매우 미비했고, 이 공기를 배기하는 경우 배출기준도 만족했다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.61.5-61
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• 2002

1. Introduction 2. Development of the Proposed Identification Method 2.1 MlMO Hammerstein nonlinear process 2.2 Process activation 2.3 Identification of the linear dynamic subsystem 2.4 Identification of the nonlinear static function 3. Simulation Study 4. Conclusion. Acknowledgment. References

• 대한환경공학회지
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• 제30권11호
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• pp.1123-1131
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• 2008

본 연구는 대기 중 PM2.5의 미량금속 중 As을 중성자방사화분석법을 이용하여 분석할 때 발생되는 측정불확도를 ISO GUM 방법과 MCS 방법을 모두 적용하여 비교, 평가하였다. 불확도의 요인은 ISO GUM을 엄격하게 준용하여 파악하였으며 특정일에 채취된 PM2.5 내 As 농도에 대해 두 방법의 계산 결과가 4% 미만으로 크게 다르지 않는 것으로 나타났다. 연구기간 중 채취된 총 60개의 PM2.5 시료에 대해 As 농도의 확장불확도를 역시 MCS 방법을 이용하여 산출하였는데, 연구지역에서의 As의 개별 농도값에 대한 95% 신뢰구간의 확장불확도는 대부분 10%의 범위에서 존재하는 것으로 나타났다. 확장불확도에 대한 표준불확도 요인의 기여율은 계측통계오차(62.3%), 검출효율(18.5%), 시료 채취 시 유량(12.3%), flux 변동(2.3%), 특정감마선 방출률(1.8%) 등의 순으로 크게 나타났다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1199-1204
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• 2003

The 3D simulations of the shielding concrete and the Rotary Specimen Rack(RSR) in the Korea Research Reactor-1&2(KRR-1&2) were carried out in present work. Four main dismantling processes, which are the removal of the RSR, reactor core region, beam tube, and thermal column and activated concrete, were selected for the graphic simulation by the consideration of the activation, worker training, work difficulty and so on. On the basis of these, we constructed their 3D CAD models and then drawn and reviewed their dismantling processes. In this study, the 3D simulation results of the shielding concrete and the RSR among main components are also presented and discussed.

• 한국지능시스템학회논문지
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• 제16권5호
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• pp.627-634
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• 2006

CMOS 인버터 특성곡선의 기울기를 조절하는 방법과 y축으로 이동할 수 있는 방법을 제안하였다. 기울기의 변경과 y축으로 이동은 트랜지스터의 문턱 값을 조절하는 방법을 사용하였다. 그리고 특성곡선의 중심에서는 두 트랜지스터 모두 포화영역에 머물러 있음에 착안하여, 단극성 뉴런의 특성곡선을 만드는 방법을 제안하였다. 제안된 방법은 회로레벨의 시뮬레이션을 통해 검증하였으며, 회로레벨의 시뮬레이션은 OrCAD사의 PSpice(Professional Simulation Program with Integrated Circuit Emphasis)를 사용하였다.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4231-4235
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• 2022

Considering the importance of deuterium in nuclear science including medical and industrial researches such as (BNCT) and nuclear reactors respectively, it is important to study various possible ways in addition to common methods for measuring its concentration. This study is an effort to measure deuterium concentration using PGNAA. The main idea is to calculate the area under 2.23 MeV gamma-rays photo peak resulting from neutron collision with Hydrogen atoms which are in mix with deuterium in samples. The study carried out by both simulation and experiment. Monte Carlo MCNPX2.6 code has been used for simulation and based on its acceptable results an experimental setup has been arranged. The coordination of results was in the range of R = 0.99 and R = 0.98 in simulation and experiment respectively. The accuracy of the study has been investigated by measuring the concentration of an unknown sample by both PGNAA and Fourier transform infrared spectroscopy (FT-IR) methods in which there were acceptable correlation between these two methods.

• 한국의류학회지
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• 제42권6호
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• pp.977-987
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• 2018

This study tests the effect of recommended product presentation on consumers' usage intentions of a website, mediated by mental simulation. Mental simulation refers to perceptual experience, a more automatic form of mental imagery, initiated by exposure to the representations of objects. This study expects that when compliments of clothes (coordination items) are vertically presented online, consumers are likely to feel as if they wear the outfits due to the activation of mental simulation. The survey was conducted on 147 women in an age group between 20 and 40 years in a panel of an online survey firm. Data are analyzed using exploratory factor analysis and bootstrapping analysis by SPSS 20.0. The results show that when compliments (vs. substitutes) of clothes are presented, participants perceive a greater mental simulation. When compliments of clothes are vertically presented (vs. horizontally presented), mental simulation is also highly driven. In addition, mental simulation mediates the effects of online product presentation on consumers' usage intentions of a website. The findings of this study contribute to marketing strategies of online retailers in terms of how product recommendation can be offered to consumers with more psychological benefits.

• Biomolecules & Therapeutics
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• 제24권2호
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• pp.191-198
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• 2016

The vitamin D receptor (VDR) is a member of the nuclear receptor (NR) superfamily. The VDR binds to active vitamin $D_3$ metabolites, which stimulates downstream transduction signaling involved in various physiological activities such as calcium homeostasis, bone mineralization, and cell differentiation. Quercetin is a widely distributed flavonoid in nature that is known to enhance transactivation of VDR target genes. However, the detailed molecular mechanism underlying VDR activation by quercetin is not well understood. We first demonstrated the interaction between quercetin and the VDR at the molecular level by using fluorescence quenching and saturation transfer difference (STD) NMR experiments. The dissociation constant ($K_d$) of quercetin and the VDR was $21.15{\pm}4.31{\mu}M$, and the mapping of quercetin subsites for VDR binding was performed using STD-NMR. The binding mode of quercetin was investigated by a docking study combined with molecular dynamics (MD) simulation. Quercetin might serve as a scaffold for the development of VDR modulators with selective biological activities.

• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1748-1751
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• 2017

Reduced activation ferritic/martensitic (RAFM) steels are widely applied as structural materials in the nuclear industry. To investigate hydrogen's effect on RAFM steels' elastic properties and the mechanism of that effect, a procedure of first principles simulation combined with experiment was designed. Density functional theory models were established to simulate RAFM steels' elastic status before and after hydrogen's insertion. Also, experiment was designed to measure the Young's modulus of RAFM steel samples with and without hydrogen charging. Both simulation and experiment showed that the solubility of hydrogen in RAFM steels would decrease the Young's modulus. The effect of hydrogen on RAFM steels' Young's modulus was more significant in water-quenched steels than it was in tempering steels. This indicated that defects inside martensite, considered to be hydrogen traps, could decrease the cohesive energy of the matrix and lead to a decrease of the Young's modulus after hydrogen insertion.

• 한국정보시스템학회지:정보시스템연구
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• 제28권1호
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• pp.115-132
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• 2019

Purpose The purpose of this study is to explain the agrophotovolatic system built by the Korea South-East Power Company and to propose methods to activate the agrophotovolatic system for the development of the renewable energy industry. Design/methodology/approach We conducted a three-step simulation in order to design a photovoltaic module, and we built the agrophotovolatic system based on the results of the simulation. Then, we analyzed the monthly generation of power and the rice harvests produced on farmland using the photovoltaic module. Based on the results of the analysis, we proposed institutional improvements to increase the use of the agrophotovolatic system, and we proposed new business models to increase the participation of farmers and business persons. Findings When we compared the agrophotovolastic system with the general photovoltaic system, we found that the agrophotovoltaic system had higher utilization rates and power generation. An analysis of rice produced on farmland using the photovoltaic module showed that more than 80% of the rice produced on general farmland was harvested. We suggested activation plans that involved the revision of the farmland law and the introduction of renewable energy certificate (REC). We also proposed a land lease model and a farmer participation model as two new business models, and we conducted economic evaluations and sensitivity analyses for both models.