Thermal cracking assessment for nuclear containment buildings using high-strength concrete

Keun-Hyeok Yang,Jae-Sung Mun,Do-Gyeum Kim,Chun-Ho Chang,Ju-Hyun Mun 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.26 No.5

To shorten the construction times of nuclear facility structures, three high-strength concrete mixtures were developed with specific consideration given to their curing temperatures, their economic efficiency, and the practicality of their quality control. This study was conducted to examine the temperature rise profiles of these three concrete mixtures and the potential for early-age thermal cracking in the primary containment vessel of a nuclear reactor with a wall thickness of 1200 mm. The one-layer placement height of the concrete for the primary containment vessel was increased from the conventional 3 m to 3.5 m. A nonlinear finite element analysis (FEA) was conducted using the thermal properties of concrete determined from the isothermal hydration and adiabatic hydration tests, and tuned through comparisons made with temperature rise profiles obtained for 1200-mm-thick mock-up wall specimens cured at temperatures of 5, 20, and 35°C. The hydration heat performance of the three concrete mixtures and their potential to produce thermal cracking in nuclear facilities indicate that the mixtures have considerable potential for practical application to the primary containment vessel of a nuclear reactor at various curing temperatures, fulfilling the minimum requirements of the ACI 301 and minimizing the likelihood of the occurrence of thermal cracks.

자철석 중량 콘크리트의 응력-변형률 관계

문주현(Mun, Ju-Hyun),문재성(Mun, Jae-Sung),양근혁(Yang, Keun-Hyeok) 대한건축학회 2013 大韓建築學會論文集 : 構造系 Vol.29 No.8

To evaluate the stress-strain relationship of heavyweight concrete (HWC) and formulate a reasonable model, 26 mixes were prepared under various parameters including water-to-binder ratio, replacement level with natural aggregate for magnetite aggregates, and the replacement level of fly ash. Based on the current test results and existing data, modulus of elasticity, and strains at the peak stress and at 50% of peak stress in the descending branch were formulated as a function of compressive strength and unit weight of concrete. The factor to determine the slopes of ascending and descending branches of the stress-strain curve was solved by numerical analysis and formulated through the parametric study. Test results demonstrated that the stress-strain behavior of concrete is significantly affected by its unit weight as well as its compressive strength. ACI 349-06 provision unconservatively predicts the modulus of elasticity of HWC, and CEB-FIP and EC2 provisions overestimate the strain at peak stress. Meanwhile, the proposed models are in good agreement with test results, giving a consistency with the trends observed in tests.

기계적이음의 미끄러짐을 고려한 프리캐스트 콘크리트 보-기둥 접합부 해석적 연구

문장혁(Mun, Jang-Hyeok),김선훈(Kim, Seon-Hoon),장웨이(Zhang Wei),이득행(Lee, Deuckhang) 대한건축학회 2023 대한건축학회 학술발표대회 논문집 Vol.43 No.2

화면 정보 관리 시스템에 관한 연구

문종혁(Jong Hyeok Mun),김석현(Suck Kyeon Kim),전병태(Byung Tae Chun) 대한전자공학회 2016 대한전자공학회 학술대회 Vol.2016 No.6

자율주행 로봇을 이용한 새로운 도서관 배가 시스템

김문혁(Kim Mun-hyeok),여건영(Yeo Gun-yeong),정은호(Jeong Eun-ho),이승환(Lee Seung-hwan) 한국정보기술학회 2019 Proceedings of KIIT Conference Vol.2019 No.6

걸음걸이 정보 분석을 위한 사용자 인터페이스

문종혁(Jong Hyeok Mun),김석현(Suck Kyeon Kim),전병태(Byung Tae Chun) 대한전자공학회 2015 대한전자공학회 학술대회 Vol.2015 No.11

신뢰성있는 딥러닝 기반 분석 모델을 참조하기 위한 딥러닝 기술 언어

문종혁 ( Jong Hyeok Mun ),김도형 ( Do Hyung Kim ),최종선 ( Jong Sun Choi ),최재영 ( Jae Young Choi ) 한국정보처리학회 2021 정보처리학회논문지. 소프트웨어 및 데이터 공학 Vol.10 No.4

최근 딥러닝은 하드웨어 성능이 향상됨에 따라 자연어 처리, 영상 인식 등의 다양한 기술에 접목되어 활용되고 있다. 이러한 기술들을 활용해 지능형 교통 시스템(ITS), 스마트홈, 헬스케어 등의 산업분야에서 데이터를 분석하여 고속도로 속도위반 차량 검출, 에너지 사용량 제어, 응급상황 등과 같은 고품질의 서비스를 제공하며, 고품질의 서비스를 제공하기 위해서는 정확도가 향상된 딥러닝 모델이 적용되어야 한다. 이를 위해 서비스 환경의 데이터를 분석하기 위한 딥러닝 모델을 개발할 때, 개발자는 신뢰성이 검증된 최신의 딥러닝 모델을 적용할 수 있어야 한다. 이는 개발자가 참조하는 딥러닝 모델에 적용된 학습 데이터셋의 정확도를 측정하여 검증할 수 있다. 이러한 검증을 위해서 개발자는 학습 데이터셋, 딥러닝의 계층구조 및 개발 환경 등과 같은 내용을 포함하는 딥러닝 모델을 문서화하여 적용하기 위한 구조적인 정보가 필요하다. 본 논문에서는 신뢰성있는 딥러닝 기반 데이터 분석 모델을 참조하기 위한 딥러닝 기술 언어를 제안한다. 제안하는 기술 언어는 신뢰성 있는 딥러닝 모델을 개발하는데 필요한 학습데이터셋, 개발 환경 및 설정 등의 정보와 더불어 딥러닝 모델의 계층구조를 표현할 수 있다. 제안하는 딥러닝 기술 언어를 이용하여 개발자는 지능형 교통 시스템에서 참조하는 분석 모델의 정확도를 검증할 수 있다. 실험에서는 제안하는 언어의 유효성을 검증하기 위해, 번호판 인식 모델을 중심으로 딥러닝 기술 문서의 적용과정을 보인다. With the recent advancements of deep learning, companies such as smart home, healthcare, and intelligent transportation systems are utilizing its functionality to provide high-quality services for vehicle detection, emergency situation detection, and controlling energy consumption. To provide reliable services in such sensitive systems, deep learning models are required to have high accuracy. In order to develop a deep learning model for analyzing previously mentioned services, developers should utilize the state of the art deep learning models that have already been verified for higher accuracy. The developers can verify the accuracy of the referenced model by validating the model on the dataset. For this validation, the developer needs structural information to document and apply deep learning models, including metadata such as learning dataset, network architecture, and development environments. In this paper, we propose a description language that represents the network architecture of the deep learning model along with its metadata that are necessary to develop a deep learning model. Through the proposed description language, developers can easily verify the accuracy of the referenced deep learning model. Our experiments demonstrate the application scenario of a deep learning description document that focuses on the license plate recognition for the detection of illegally parked vehicles.

장애 아동 부모의 사회적지지가 가족기능에 미치는 영향: 장애수용의 매개효과와 경제적 안정감의 조절효과

문종혁(Jong-Hyeok Mun) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.6

본 연구는 아동발달센터에서 치료 및 훈련을 받는 발달장애를 가진 아동의 부모를 대상으로 사회적지지, 장애수용, 경제적 안정감, 가족기능 간의 관계를 규명하는데 그 목적을 두었다. 이를 위하여 S시 소재 아동발달센터를 이용하는 발달장애 아동의 부모 252명을 대상으로 설문조사를 실시하였다. 사회적지지와 가족기능 간의 관계에서 장애수용의 매개효과와 사회적지지, 장애수용과 가족기능 간의 관계에서 경제적 안정감의 조절효과를 검증하기 위하여 매개효과 3단계 검증 절차와 위계적 다중회귀분석을 활용하였다. 본 연구 결과는 다음과 같다. 첫째, 조절변인인 경제적 안정감의 조절효과를 확인한 결과 사회적 지지와 가족기능 및 장애수용과 가족기능간의 관계 모두 경제적 안정감의 조절효과는 없는 것으로 나타났다. 둘째, 사회적 지지와 가족기능간의 관계를 장애수용이 매개하는지 검증한 결과, 사회적 지지와 가족기능의 관계를 장애수용이 부분매개하는 것으로 나타났다. 본 연구는 발달장애를 가진 아동의 가정이 제대로 기능할 수 있도록 돕는 프로그램 개발에 기초자료를 제공하였다는 점에서 의의가 있다. This study seeks to discuss the effects of social support, acceptance of disability, and the sense of economic stability on the part of parents of children with developmental disabilities who are receiving treatment and training at a child development center has on family function. A survey was given to 252 parents of children who were using the child development center in S city. In the relationship between social support and family function, the mediating effects of the disability acceptance and the social support, the disability acceptance and the family function were used to verify the adjustment effect of the economic stability. The results of this study are as follows. First, as a result of checking the moderating effect of economic stabilization, social support, family function, disability acceptance and family function did not show any effect on economic stability. Second, as a result of verifying whether the relationship between social support and family function is mediated by disability acceptance, disability acceptance partially mediated the relationship between social support and family function. This study is significant in that it provided basic data for the development of a program to help children with developmental disabilities function properly.

난류 유동을 갖는 가스 포일 저널 베어링의 성능 예측

문진혁(Jin Hyeok Mun),김태호(Tae Ho Kim) 한국트라이볼로지학회 2019 한국윤활학회지(윤활학회지) Vol.35 No.3

Gas foil bearings (GFBs) enable small- to medium-sized turbomachinery to operate at ultra-high speeds in a compact design by using ambient air or process gas as a lubricant. When using air or process gas, which have lower viscosity than lubricant oil, the turbomachinery has the advantage of reduced power loss from bearing friction drag. However, GFBs may have high Reynolds number, which causes turbulent flows due to process gas with low viscosity and high density. This paper analyzes gas foil journal bearings (GFJBs) with high Reynolds numbers and studies the effects of turbulent flows on the static and dynamic performance of bearings. For comparison purposes, air and R-134a gas lubricants are applied to the GFJBs. For the air lubricant, turbulence is dominant only at rotor speeds higher than 200 krpm. At those speeds, the journal eccentricity decreases, but the film thickness, power loss, and direct stiffness and damping coefficients increase. On the other hand, the R-134a gas lubricant, which that has much higher density than air, causes dominant turbulence at rotor speeds greater than 10 krpm. The turbulent flow model predicts decreased journal eccentricity but increased film thickness and power loss when compared with the lamina flow model predictions. The vertical direct stiffness and damping coefficients are lower at speeds below 100 krpm, but higher beyond that speeds for the turbulent model. The present results indicate that turbulent flow effects should be considered for accurate performance predictions of GFJBs with high Reynolds number.

疏風活血湯 및 疏風活血湯加蜂毒이 瘀血病態에 미치는 影響

梁文赫(Yang Mun-Hyeok),崔昇勳(Choi Seung-Hoon),安圭錫(Ahn Kyoo-Seok) 대한한의학회 1994 대한한의학회지 Vol.15 No.1