구조물 및 기기의 한계성능 평가를 위한 고진동수 지진특성을 반영한 응답스펙트럼 형상

임승현,최인길 한국지진공학회 2020 한국지진공학회논문집 Vol.24 No.1

In 2016, an earthquake occurred at Gyeongju, Korea. At the Wolsong site, the observed peak ground acceleration was lower than the operating basis earthquake (OBE) level of Wolsong nuclear power plant. However, the measured spectral acceleration value exceeded the spectral acceleration of the operating-basis earthquake (OBE) level in some sections of the response spectrum, resulting in a manual shutdown of the nuclear power plant. Analysis of the response spectra shape of the Gyeongju earthquake motion showed that the high-frequency components are stronger than the response spectra shape used in nuclear power plant design. Therefore, the seismic performance evaluation of structures and equipment of nuclear power plants should be made to reflect the characteristics of site-specific earthquakes. In general, the floor response spectrum shape at the installation site or the generalized response spectrum shape is used for the seismic performance evaluation of structures and equipment. In this study, a generalized response spectrum shape is proposed for seismic performance evaluation of structures and equipment for nuclear power plants. The proposed response spectrum shape reflects the characteristics of earthquake motion in Korea through earthquake hazard analysis, and it can be applied to structures and equipment at various locations.

심장판막증이 동반된 관상동정맥루 -수술치험 1례-

임승현 대한흉부심장혈관외과학회 1994 Journal of Chest Surgery (J Chest Surg) Vol.27 No.7

Congenital coronary arteriovenous fistula is a rare cardiac defect that causes coronary arterial flow to drain into the right cardiac chambers, the pulmonary artery, the coronary sinus, or the left cardiac chambers. The most frequently involved vessel is the right coronary artery. We experienced a case that had a coronary arteriovenous fistula associated with valvular heart disease. With the cardiopulmonary bypass done under hypothermia, mitral valve replacement was accomplished and the fistulas of both proximal and distal portions of the right coronary artery were closed with 3-0 prolene. Postoperative course was uneventful.

다중기기 손상 상관성에 의한 지진리스크 영향 분석

임승현,최인길,Eem, Seung-Hyun,Choi, In-Kil 한국지진공학회 2019 한국지진공학회논문집 Vol.23 No.2

The seismic safety of nuclear power plants has always been emphasized by the effects of accidents. In general, the seismic safety evaluation of nuclear power plants carries out a seismic probabilistic safety assessment. The current probabilistic safety assessment assumes that damage to the structure, system, and components (SSCs) occurs independently to each other or perfect dependently to each other. In case of earthquake events, the failure event occurs with the correlation due to the correlation between the seismic response of the SSCs and the seismic performance of the SSCs. In this study, the EEMS (External Event Mensuration System) code is developed which can perform the seismic probabilistic safety assessment considering correlation. The developed code is verified by comparing with the multiplier n, which is for calculating the joint probability of failure, which is proposed by Mankamo. It is analyzed the changes in seismic fragility curves and seismic risks with correlation. As a result, it was confirmed that the seismic fragility curves and seismic risk change according to the failure correlation coefficient. This means that it is important to select an appropriate failure correlation coefficient in order to perform a seismic probabilistic safety assessment. And also, it was confirmed that carrying out the seismic probabilistic safety assessment in consideration of the seismic correlation provides more realistic results, rather than providing conservative or non-conservative results comparing with that damage to the SSCs occurs independently.

스포츠센터 이용자의 선택속성이 공동체의식과 사회적상호작용에 미치는 영향

임승현,남경완 학습자중심교과교육학회 2023 학습자중심교과교육연구 Vol.23 No.15

Objectives The purposes of this study were to influences of choice characteristics of sport center users on community spirit and social interactions. Methods The study was conducted with collection and analysis of the data on the subjects consisting of 299 users of three sports centers in D Metropolitan City in order to identify the influences of choice characteristics of sport center users on community spirit and social interactions. Collected data were processed with frequency analysis and factor analysis, reliability analysis, correlation analysis, and regression analysis with use of Windows SPSS 29.0 program, and the conclusion was obtained as shown below. Results First, choice characteristics showed positive correlation to all sub-factors of community spirit and social support in social interactions but showed negative correlation to stigmatization in social interactions. Second, factors of facilities and programs in choice characteristics of sport center users showed positive influences on sub-factors of community spirit such as intimacy and belonging, harmony and unity, expression of intention of voluntary participation, identification and sharing of merits and demerits, and autonomy and public consciousness and accessibility factor showed positive influences to intention of voluntary participation and authoritative collectivism. Third, program and accessibility factors in choice characteristics of sport center users showed positive influences on social support and stigmatization factors in social interactions and cost factors showed positive influences on social support in social interactions but negative influences on stigmatization factors. Conclusions In conclusion, the influences of choice characteristics of sports center users affect community spirit and social interaction.

체육전공 대학생의 사회적지지와 가족건강성이 결혼관에 미치는 영향

임승현,김명미,박상섭 충북대학교 국가미래기술경영연구소 2022 기술경영 Vol.7 No.3

본 연구는 체육전공 대학생의 사회적 지지와 가족건강성이 결혼관에 미치는 영향 규명하기 위해서 D광역시 2개, K시 2개 지역에 소재한 대학 체육전공 재학생 남녀 457명을 대상으로 실시하였다. 수집된 자료는 SPSS Ver. 24.0 프로그램을 이용하여 빈도분석, 상관분석, 다중회귀분석을 실시하여 연구결과를 도출하였다. 도출된 연구결과는 사회적 지지와 가족건강성은 정적 상관관계가 있는 것으로 나타났으며, 사회적 지지와 가족건강성, 결혼관의 하위요인들은 부적 상관관계가 있는 것으로 나타났다. 또한 가족 유연성 요인은 결혼관에 부정적인 영향을 미치는 것으로 나타났으며, 경제적 안정요인은 가족문화 및 사회참여 요인에 긍정적인 영향을 미치는 것으로 나타났다. MZ세대 대학생들은 혼자이거나 혼자 술 마시기 등 혼자 살기에 충분한 환경에서 혼자 행복하게 살 수 있다고 생각하고 있어 결혼에 대한 생각과 가치관의 변화가 필요하다.

저전력 전자공명 수소 플라즈마를 이용한 저온 건식 접촉 구멍 세정화

임승현,박진원,여환국,윤의준,이상인 대한전자공학회 1998 대한전자공학회 학술대회 Vol.1998 No.1

도시재생 주민공모사업의 효과 및 영향요인 분석 - 천안 남산지구를 대상으로

임승현,이경환 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.1

본 연구는 천안시 남산지구를 대상으로 도시재생 주민공모사업의 효과 및 영향요인을 실증적으로 분석하고 이를토대로 향후 주민공모사업 활성화를 위한 정책적 함의를 도출하는데 목적이 있다. 이를 위해 남산지구 주민공모사업 참여자들을 대상으로 한 설문조사를 통해 연구를 진행하였으며, 구체적으로는 구조방정식 모형을 활용하였다. 주요 연구결과를 요약하면 다음과 같다. 첫째, 주민공모사업에 대한 평가결과 주민공모사업에 대한 만족도는 4.31점으로 비교적 높게 나타났다. 둘째, 연령대가 높고 학생일수록 주민공모사업에 대한 만족도가 높으며, 주체 간 협력, 프로그램 과정이주민공모사업 만족도에 영향을 미치는 것으로 나타났다. 셋째, 주민공모사업을 통해 지역주민, 학생들의 도시재생사업에대한 이해수준이 향상되었으며, 주체 간 협력, 프로그램 과정에 대한 만족도, 공공기관 지원이 도시재생사업의 이해에긍정적인 영향을 미치는 것으로 나타났다. 또한 주민공모사업 참여정도, 도시재생사업의 이해, 주민공모사업 만족도가재생사업 참여의지에 영향을 미치는 것으로 나타났다. 넷째, 주민공모사업 참여정도, 주민공모사업 만족도가 장소애착과공동체 의식에 영향을 미치며, 주민공모사업에 대한 평가는 도시재생사업에 대한 이해를 매개로 재생사업 참여의지에영향을 미치는 것으로 나타났다. 따라서 주민공모사업은 도시재생사업과 연계하여 도시재생사업 이해 증진, 지역 인적자원 발굴을 위해 활용될 필요가 있으며, 다년도 사업 기획 및 연속적 지원이 확대되어야 한다.

구조물 및 기기의 내진성능 평가를 위한 고주파수 지진에 의한 원자력발전소의 지진응답 증폭계수

임승현,최인길,전법규,곽신영,Eem, Seung-Hyun,Choi, In-Kil,Jeon, Bub-Gyu,Kwag, Shinyoung 한국지진공학회 2020 한국지진공학회논문집 Vol.24 No.3

Analysis of the 2016 Gyeongju earthquake and the 2017 Pohang earthquake showed the characteristics of a typical high-frequency earthquake with many high-frequency components, short time strong motion duration, and large peak ground acceleration relative to the magnitude of the earthquake. Domestic nuclear power plants were designed and evaluated based on NRC's Regulatory Guide 1.60 design response spectrum, which had a great deal of energy in the low-frequency range. Therefore, nuclear power plants should carry out seismic verification and seismic performance evaluation of systems, structures, and components by reflecting the domestic characteristics of earthquakes. In this study, high-frequency amplification factors that can be used for seismic verification and seismic performance evaluation of nuclear power plant systems, structures, and equipment were analyzed. In order to analyze the high-frequency amplification factor, five sets of seismic time history were generated, which were matched with the uniform hazard response spectrum to reflect the characteristics of domestic earthquake motion. The nuclear power plant was subjected to seismic analysis for the construction of the Korean standard nuclear power plant, OPR1000, which is a reactor building, an auxiliary building assembly, a component cooling water heat exchanger building, and an essential service water building. Based on the results of the seismic analysis, a high-frequency amplification factor was derived upon the calculation of the floor response spectrum of the important locations of nuclear power plants. The high-frequency amplification factor can be effectively used for the seismic verification and seismic performance evaluation of electric equipment which are sensitive to high-frequency earthquakes.

수치해석에 의한 환수 헤더의 혼합 후 냉수 온도 균일성 개선

임승현,김영일 대한설비공학회 2023 설비공학 논문집 Vol.35 No.7

For a precision electronic component manufacturing factory, stable operation of production equipment is essential for high-quality products. In particular, reliable water supply is crucial as the production equipment is sensitive to changes in the supplied cold water temperatures. The type and scale of product manufacturing, as well as the market conditions, lead to changes in the specifications, arrangement and quantities of production equipment. Additionally, adjustments and modifications have been made to the cold water supply system. In general, chilled water system use headers when there are multiple loads. However, the return temperature of the production equipment is often supplied at a temperature different from the original design, which can cause problems with the operation and final product quality. CFD was performed to identify the cause of these problems and to propose design criteria for cold water return headers that improves temperature uniformity. A correlation equation was proposed to propose an appropriate header length that satisfies the temperature uniformity of the return header with respect to the flow rate ratio.

초등학교 6학년 학생들의 도형의 높이 개념 이해에 대한 연구

임승현,박영희 한국초등수학교육학회 2011 한국초등수학교육학회지 Vol.15 No.1

본 연구에서 초등학교 6학년 학생들이 도형의 높이 개념을 이해하는 데 어떠한 특징을 보이는지 알아보기 위하여 초등학교 6학년 학생들이 평면도형(삼각형, 평행사변형, 사다리꼴), 입체도형(원뿔, 원기둥, 각기둥, 각뿔)의 높이 개념 이해에서 어떠한 특징을 보이는지를 알아보았다. 그 결과로 학생들은 평면도형의 높이 측정에서 밑변이 수형하지 않은 도형에서 어려움을 나타냈고, 일상의 높이 경험과 연관되는 오류를 보이고, 높이 개념을 언어적으로 표현하는 데에 어려움을 느끼고 있음을 알 수 있었다. The purpose of the present research is to suggest implications on guidance of height concept understanding of figures by investigating concept understanding how sixth grade's elementary school students understand a height concept of figures. In order to achieve this research purpose, a height concept understanding test of figures was carried out with the target of 54 sixth grade students who already learned a height concept of plane figures and three-dimensional solid figures, and thus this research analyzed characteristics and errors appeared there. When analyzing its characteristics and errors, interviews with students were carried out for in-depth analysis. And as a result, the following implications could be obtained. First, students felt more difficulty in measuring height in a figure that its lower base is not horizontal in questions measuring height of a plane figure. Second, there were cases that students associate a height concept of figures with experience of height experienced in daily life. Third, students were feeling difficulty in linguistically expressing a concept called height that oneself has. Expressing a concept linguistically plays an important role in understanding a concept clearly. Accordingly, activities for raising this mathematical communication ability are required. Fourth, the present research can suggest implications in designing classes that students can clearly understand the height concept of figures.