Safety evaluation of supercritical CO₂ cooled micro modular reactor

Oh, Bong Seong,Ahn, Yoon Han,Yu, Hwanyeal,Moon, Jangsik,Kim, Seong Gu,Cho, Seong Kuk,Kim, Yonghee,Jeong, Yong Hoon,Lee, Jeong Ik Elsevier 2017 Annals of nuclear energy Vol.110 No.-

<P><B>Abstract</B></P> <P>To meet the energy requirement for a remote and isolated region, a concept of supercritical CO<SUB>2</SUB> (S-CO<SUB>2</SUB>) cooled micro modular reactor (MMR) has been developed, which is easy to transport by fully modularizing the nuclear power system. From the previous work, only the on-design performances of MMR were presented. However, since the nuclear system needs to meet high safety standard, the design can be finalized only after the evaluation of the nuclear system response under multiple transient conditions. Such transient conditions may include part load operation and postulated accidents. The system response can be evaluated only with a high fidelity computer simulation, since it is almost impossible to construct a nuclear facility to test at such conditions. The simulation is performed to guarantee its autonomous operability and safety. Unfortunately, a system analysis computer code available for the S-CO<SUB>2</SUB> cycle analysis is yet to be developed for the MMR safety evaluation. Description of aS-CO<SUB>2</SUB> system analysis code platform is first presented in this paper. After that, the developed code is validated with experimental data. The steady state of MMR is first modeled with the code, which is followed by simulations of part load operation and postulated accidents of MMR. All simulation results show that the current design of MMR has the ability to maintain its safety and structural integrity even under extreme conditions to protect the public from radiation hazard at all times.</P>

SLAM 기술을 활용한 가상 환경 복원 및 드론 레이싱 시뮬레이션 제작

박용희(Yonghee Park),유승현(Seunghyun Yu),이재광(Jaegwang Lee),정종현(Jonghyeon Jeong),조준형(Junhyeong Jo),김소연(Soyeon Kim),오혜준(Hyejun Oh),문형필(Hyungpil Moon) 한국로봇학회(논문지) 2021 로봇학회 논문지 Vol.16 No.3

연구로 고정 볼트 설계 인자 분석

류용희(Yonghee Ryu),오진호(Jinho Oh),곽진성(Jinsung Kwak) 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.5

Development and validation of multiphysics PWR core simulator KANT

Taesuk Oh,Yunseok Jeong,Husam Khalefih,Yonghee Kim Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

KANT (KAIST Advanced Nuclear Tachygraphy) is a PWR core simulator recently developed at Korea Advance Institute of Science and Technology, which solves three-dimensional steady-state and transient multigroup neutron diffusion equations under Cartesian geometries alongside the incorporation of thermal-hydraulics feedback effect for multi-physics calculation. It utilizes the standard Nodal Expansion Method (NEM) accelerated with various Coarse Mesh Finite Difference (CMFD) methods for neutronics calculation. For thermal-hydraulics (TH) calculation, a single-phase flow model and a one-dimensional cylindrical fuel rod heat conduction model are employed. The time-dependent neutronics and TH calculations are numerically solved through an implicit Euler scheme, where a detailed coupling strategy is presented in this paper alongside a description of nodal equivalence, macroscopic depletion, and pin power reconstruction. For validation of the steady, transient, and depletion calculation with pin power reconstruction capacity of KANT, solutions for various benchmark problems are presented. The IAEA 3-D PWR and 4-group KOEBERG problems were considered for the steady-state reactor benchmark problem. For transient calculations, LMW (Lagenbuch, Maurer and Werner) LWR and NEACRP 3-D PWR benchmarks were solved, where the latter problem includes thermal-hydraulics feedback. For macroscopic depletion with pin power reconstruction, a small PWR problem modified with KAIST benchmark model was solved. For validation of the multi-physics analysis capability of KANT concerning large-sized PWRs, the BEAVRS Cycle1 benchmark has been considered. It was found that KANT solutions are accurate and consistent compared to other published works.

어머니 행복감, 교사-유아 친밀관계, 유아 자아존중감이 유아의 자기조절력에 미치는 영향

이용희(Lee, YongHee),오선진(Oh, SunJin) 한국열린유아교육학회 2018 열린유아교육연구 Vol.23 No.3

본 연구의 목적은 자기조절력 형성이 이루어지는 시기의 유아를 대상으로 어머니의 행복감과 교사-유아 친밀관계 및 유아의 자아존중감이 자기조절력에 미치는 영향을 알아봄으로써 유아의 자기조절력에 긍정적인 영향을 주는 변인을 알아보고 자기조절력 발달에 필요한 내적․외적 환경을 제공하는데 있다. 유아교육기관에 재원 중인 만 4세와 만 5세 담임교사와 어머니를 대상으로 선정하였고, 어머니용과 교사용의 설문지를 각 350부를 배부하였다. 교사와 유아의 비율은 교사 1인이 무작위로 10명의 유아를 선정하였다. 어머니는 어머니의 행복감과 주유아의 자기조절력에 대한 설문에 응답하였으며 유아의 담임교사는 교사-유아 친밀관계와 유아의 자아존중감에 대한 설문에 응답하였다. 회수된 318쌍의 설문지 중 중복 응답을 하거나 누락된 문항이 있는 18쌍을 제외한 총 300명의 유아와 어머니, 30명의 교사를 본 연구 대상으로 하였다. 연구결과 어머니 행복감과 유아 자아존중감이 높을수록 유아 자기조절력은 높아지는 것으로 나타나 어머니 행복감과 유아 자아존중감이 유아 자기조절력에 긍정적인 영향을 미치는 주요 예측 변인임을 알 수 있다. The purpose of this study is to examine the effects of mother’s happiness, teacher-child intimate relationship, and children’s self-esteem on children’s self-regulation. For the purpose of this study, 300 mothers of children between the age of 4 and 5 registered at early childhood educational institution and 30 teachers of these children were selected for analysis. Questionnaires about mother’s happiness and children’s self-regulation were assessed by mothers who participated in this study and teacher-child intimate relationship and children’s self-esteem were measured by children’s teachers. Main results are following. There was statistically positive relationship between total scores of children’s self-regulation, mother’s happiness, teacher-child intimate relationship, and children’s self-esteem. According to the results of hierarchical multiple regression analysis, mother’s happiness and children’s self-esteem had a significant positive effect on children’s self-regulation ability, but teacher-child intimate relationship did not have any significant effect on children’s self-regulation ability. Based on these major results of this study, mother’s happiness and children’s self-esteem would be the vital factor having positive effect on children’s self-regulation ability.

사운드 기반 진동 시스템을 위한 진동 패턴 에디터와 컨트롤러

오성진 (Sungjin Oh),조동현(Donghyun Cho),유용희(Yonghee You),성미영 (Mee Young Sung),전경구(Kyungkoo Jun) 한국HCI학회 2008 한국HCI학회 학술대회 Vol.2008 No.2

본 논문에서는 사운드 기반 진동 시스템을 위한 진동 패턴 에디터와 진동 패드를 제어하기 위한 컨트롤러를 개발한다. 사운드 기반 진동 시스템은 PC의 사운드 출력단자로부터 나오는 신호를 실시간으로 분석하여 다양한 진동 효과를 발생시키는 시스템이다. 이것은 사운드 분석을 위한 DSP 시스템, 사용자의 팔 등에 부착하여 진동을 전달하는 진동 패드, 그리고 이를 제어하는 컨트롤러로 구성된다. 진동 패턴 에디터에서는 패턴을 결정하는 요소를 진동소자 위치, 진동 시작시간, 지속시간, 세기의 네 가지로 정의하고, 이러한 패턴을 쉽고 빠르게 생성할 수 있는 GUI기반 사용자 인터페이스를 제공한다. 이렇게 정의된 패턴은 저장이 가능하여 재사용성이 높다. 또한 진동 패턴 데이터를 해석하여 진동 패드를 제어하는 컨트롤러 구조를 제안한다. 이 경우 진동 패턴에 따라 컨트롤러의 펌웨어를 수정해야 하는 불편함을 없앨 수 있다. In this paper, we develop a vibration pattern editor and a vibration pad controller for a sound-driven vibration system, which can generate diverse vibration effects in realtime by analyzing signals from the sound output of PC. It consists of a DSP system to analyze the sound, a wrist-wearable vibration pad, and its controller. For the vibration pattern editor, we define four elements to describe the pattern; the locations of vibrating elements, start time, duration, and vibration intensity. The editor provides a GUI through which users can create such patterns fast and easily, and store them for reuse. We also propose a pattern-interpreting controller. It is able to interpret patterns created by the editor and control the pad accordingly. It can avoid the need to change the controller firmware whenever desired patterns change.

대용량 RO 해수 담수화 플랜트 전처리 기술 고찰

오호영(Hoyoung Oh),안용희(Yonghee Ahn),정몽규(Mongkyu Chung),소용신(Yongshin So) 한국유체기계학회 2013 한국유체기계학회 학술대회 논문집 Vol.2013 No.11

X-ray 영상개선을 위한 Pyramid Method의 CUDA 구현에 관한 연구

오일환(Ilhwan, Oh),김관우(Kwanwoo Kim),김순석(Soonseok. Kim),김동호(Dongho Kim),이강우(Kangwoo Lee),김영모(Youngmo Kim),이용희(Yonghee Lee) 한국통신학회 2014 한국통신학회 학술대회논문집 Vol.2014 No.1

Effect of Lactobacillus Fermentation on the Anti-Inflammatory Potential of Turmeric

( Cheng Chung Yong ),( Yonghee Yoon ),( Hee Sub Yoo ),( Sejong Oh ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.10

Curcumin, the major bioactive constituent of turmeric, has been reported to have a wide range of pharmacological benefits; however, the low solubility in water has restricted its systemic bioavailability and therapeutic potential. Therefore, in the current study, we aimed to investigate the effect of turmeric fermentation on its curcumin content and anti-inflammatory activity by using several lactic acid bacteria. Fermentation with Lactobacillus fermentum significantly increased the curcumin content by 9.76% while showing no cytotoxicity in RAW 246.7 cells, as compared to the unfermented turmeric, regardless of the concentration of L. fermentum-fermented turmeric. The L. fermentum-fermented turmeric also promoted cell survival; a significantly higher number of viable cells in lipopolysaccharide (LPS)-induced RAW 264.7 cells were observed as compared to those treated with unfermented turmeric. It also displayed promising DPPH scavenging (7.88 ± 3.36%) and anti-inflammatory activities by significantly reducing the nitrite level and suppressing the expression of the pro-apoptotic tumor necrosis factor-alpha and Toll-like receptor-4 in LPS-induced RAW 264.7 cells. Western blot analysis further revealed that the anti-inflammatory activity of the fermented turmeric was exerted through suppression of the c-Jun N-terminal kinase signal pathway, but not in unfermented turmeric. Taken together, the results suggested that fermentation with lactic acid bacteria increases the curcumin content of turmeric without increasing its cytotoxicity, while strengthening the specific pharmacological activity, thus, highlighting its potential application as a functional food ingredient.

Bacillus subtilis FWC1, B. amyloliquefaciens NAAS1 및 Pichia farinosa NAAS2의 산업적 생산을 위한 배양 조건

유희섭 ( Heeseop Yoo ),윤용희 ( Yonghee Yoon ),오세종 ( Sejong Oh ) 한국낙농식품응용생물학회 2021 Journal of Dairy Science and Biotechnology (JMSB) Vol.39 No.3

This study analyzed and compared growth characteristics under large-scale fermentation at 35℃ of three microorganisms with the ability to reduce odor-producing substances in livestock. The three microorganisms (Bacillus subtilis FWC1, Bacillus amyloliquefaciens NAAS1, and Pichia farinosa NAAS2) evaluated in this study have been proven effective in reducing odor-inducing substances. Bacillus subtilis FWC1 exhibited the highest viable cell count when using 2% maltodextrin as carbon source, 0.05% soy-peptone as nitrogen source, and 0.3% yeast extract. The optimum media composition for B. amyloliquefaciens NAAS1 was 1.2% modified-starch with 0.8% yeast extract. The spore formation rate in the mass production of the Bacillus strains was over 90%, indicating that optimal growth medium compositions have been identified. In the case of P. farinosa NAAS2, our optimized growth medium [2% (w/v) glucose and 1% (w/v) yeast extract] improved biomass production.