국내 지진동 특성에 대한 기기 용접 정착부의 비탄성에너지 흡수계수를 고려한 지진취약도 평가

임승현,김건규,최인길,곽신영 한국지진공학회 2023 한국지진공학회논문집 Vol.27 No.1

In Korea, most nuclear power plants were designed based on the design response spectrum of Regulatory Guide 1.60 of the NRC. However, in the case of earthquakes occurring in the country, the characteristics of seismic motions in Korea and the design response spectrum differed. The seismic motion in Korea had a higher spectral acceleration in the high-frequency range compared to the design response spectrum. The seismic capacity may be reduced when evaluating the seismic performance of the equipment with high-frequency earthquakes compared with what is evaluated by the design response spectrum for the equipment with a high natural frequency. Therefore, EPRI proposed the inelastic energy absorption factor for the equipment anchorage. In this study, the seismic performance of welding anchorage was evaluated by considering domestic seismic characteristics and EPRI's inelastic energy absorption factor. In order to reflect the characteristics of domestic earthquakes, the uniform hazard response spectrum (UHRS) of Uljin was used. Moreover, the seismic performance of the equipment was evaluated with a design response spectrum of R.G.1.60 and a uniform hazard response spectrum (UHRS) as seismic inputs. As a result, it was confirmed that the seismic performance of the weld anchorage could be increased when the inelastic energy absorption factor is used. Also, a comparative analysis was performed on the seismic capacity of the anchorage of equipment by the welding and the extended bolt.

Opendata 기반 포항 및 경주지진에 의한 건물손상 평가

임승현,양범주,전해민 한국지진공학회 2018 한국지진공학회논문집 Vol.22 No.3

Severe earthquakes can cause damage to society both socially and economically. An appropriate initial response can alleviate damage from severe earthquakes. In order to formulate an appropriate initial response, it is necessary to identify damage situations in societies; however, it is difficult to grasp this information immediately after an earthquake event. In this study, an earthquake damage assessment methodology for buildings is proposed for estimating damage situations immediately after severe earthquakes. A response spectrum database is constructed to provide response spectra at arbitrary locations from earthquake measurements immediately after the event. The fragility curves are used to estimate the damage of the buildings. Earthquake damage assessment is performed from the response spectrum database at the building scale to provide enhanced damage condition information. Earthquake damage assessment for Gyeongju city and Pohang city were conducted using the proposed methodology, when an earthquake occurred on September 12, 2016, and November 15, 2017. Results confirm that the proposed earthquake damage assessment effectively represented the earthquake damage situation in the city to decide on an appropriate initial response by providing detailed information at the building scale.

포항지진에 대한 원자력발전소 구조물 및 기기의 지진응답 분석

임승현,최인길 한국지진공학회 2018 한국지진공학회논문집 Vol.22 No.3

The probabilistic seismic safety assessment is one of the methodology to evaluate the seismic safety of the nuclear power plants. The site characteristics of the nuclear power plant should be reflected when evaluating the seismic safety of the nuclear power plant. The Korea seismic characteristics are strong in high frequency region and may be different from NRC Regulatory Guide 1.60, which is the design spectrum of nuclear power plants. In this study, seismic response of a nuclear power plant structure by Pohang earthquake (2017.11.15. (KST)) is investigated. The Pohang earthquake measured at the Cheongsong seismic observation station (CHS) is scaled to the peak ground acceleration (PGA) of 0.2 g and the seismic acceleration time history curve corresponding to the design spectrum is created. A nuclear power plant of the containment building and the auxiliary buildings are modeled using OPENSEES to analyze the seismic response of the Pohang earthquake. The seismic behavior of the nuclear power plant due to the Pohang earthquake is investigated. And the seismic performances of the equipment of a nuclear power plant are evaluated by the HCLPF. As a result, the seismic safety evaluation of nuclear power plants should be evaluated based on site-specific characteristics of nuclear power plants.

실내골프연습장 고객의 라이프스타일 분석

임승현,남경완 한국스포츠리서치 2007 한국 스포츠 리서치 Vol.18 No.6

지반-구조물 상호작용 효과를 고려한 지진격리시스템이 적용된 원전 격납건물의 지진 취약도 평가

임승현,정형조,김민규,최인길 한국지진공학회 2013 한국지진공학회논문집 Vol.17 No.2

Several researches have been studied to enhance the seismic performance of nuclear power plants (NPPs) by application of seismic isolation. If a seismic base isolation system is applied to NPPs, seismic performance of nuclear power plants should be reevaluated considering the soil-structure interaction effect. The seismic fragility analysis method has been used as a quantitative seismic safety evaluation method for the NPP structures and equipment. In this study, the seismic performance of an isolated NPP is evaluated by seismic fragility curves considering the soil-structure interaction effect. The designed seismic isolation is introduced to a containment building of Shin-Kori NPP which is KSNP (Korean Standard Nuclear Power Plant), to improve its seismic performance. The seismic analysis is performed considering the soil-structure interaction effect by using the linearized model of seismic isolation with SASSI (System for Analysis of Soil-Structure Interaction) program. Finally, the seismic fragility is evaluated based on soil-isolation-structure interaction analysis results.

웹을 이용한 원격 시스템 GUI 개발

임승현,전재욱 成均館大學校 科學技術硏究所 1999 論文集 Vol.50 No.1

In this paper we propose a GUI for teleoperation system using Web. The proposed GUI is based on recent Web technologies such as browsers, Java language and socket communication. It allows users to connect to our object system through a Web server, using their personal computer.

가스절연개폐장치의 스페이서 내장형 전자식 변압기의 설계 및 제작

임승현,김남훈,김동언,김선규,길경석 한국전기전자재료학회 2022 전기전자재료학회논문지 Vol.35 No.4

Bulky iron-core potential transformers (PT) are installed in a tank of gas insulated switchgears (GIS) for a system voltage measurement in power substations. In this paper, we studied an electronic voltage transformer (EVT) embedded in a spacer for miniaturization, eco-friendliness, and performance improvement of GIS. The prototype EVT consists of a capacitive probe (CP) that can be embedded in a spacer and a voltage Follower with a high input and a low output impedance. The CP was fabricated in the form of a Flexible-PCB to acquire the insulation performance and to withstand vibration and shock during operation. Voltage ratio of the prototype EVT is about 42,270, and the frequency bandwidth of –3 dB ranges from 0.33 Hz to 3.9 MHz. The voltage ratio error evaluated at about 6%, 12% and 18% of the rated voltage of 170 kV was 0.32%, and the phase error was 12.9 minutes. These results were within the accuracy for the class 0.5 specified in IEC 60044-7 and satisfy even in ranges from 80% to 120% of the rated voltage. If the prototype EVT replaces the conventional iron-core potential transformer, it is expected that the height of the GIS could be reduced by 11% and the amount of SF6 will be reduced by at least 10%.

63Sn-37Pb 솔더 스트립에서의 Electromigration 거동

임승현,최재훈,오태성,Lim Seung-Hyun,Choi Jae-Hoon,Oh Tae-Sung 한국마이크로전자및패키징학회 2004 마이크로전자 및 패키징학회지 Vol.11 No.2

63Sn-37Pb 공정솔더의 electromigration 현상을 용이하게 관찰하기 위해 63Sn-37Pb 공정솔 더를 증착하여 스트립 형태의 시편을 제작 후 electromigration 테스트를 실시하였다. $80{\sim}150^{\circ}C$의 온도 및 $1{\times}10^4{\sim}1{\times}10^5\;A/cm^2$의 전류밀도에서 electromigration 테스트시 스트립 형상의 63Sn-37Pb 솔더 합금에서 hillock과 void의 발생이 관찰되었으며, 온도와 전류밀도가 높아질수록 void의 형성이 빨라져서 평균파괴시간이 단축되었다. 평균파괴시간을 이용하여 Black의 식으로부터 구한 63Sn-37Pb 솔더 스트립의 electromigration에 대한 활성화 에너지는 $0.16{\sim}0.5\;eV$이었다. To facilitate the observation of the electromigration of 63Sn-37Pb eutectic solder, strip-type samples were fabricated by solder evaporation. The electromigration test for the 63Sn-37Pb solder strip was conducted at temperatures of $80{\sim}150^{\circ}C$ and the current densities of $1{\times}10^4{\sim}1{\times}10^5\;A/cm^2$. With increasing temperature and the current density, mean-time-to-failure(MTTF) decreased due to the formation of hillock and void in the solder strip. The activation energy for the electromigration in the 63Sn-37Pb solder strip was analyzed as $0.16{\sim}0.5\;eV$ using Black's equation.

우리나라 [체육] 명칭에 관한 고찰

임승현,남경완,배준원,박미향 한국스포츠리서치 2006 한국 스포츠 리서치 Vol.17 No.6

토양의 온도와 수분이 크리핑 벤트그래스 (Agrostis palustris Huds) 생육에 미치는 영향

임승현,정준기,김기동,주영규 한국잔디학회 2009 Weed & Turfgrass Science Vol.23 No.2

The high temperature and water content in soil profile probably affect the physiological disorder especially on cool-season turfgrasses in warm and humid weather of Korean summer. The purpose of this research was to analyze the effect of soil temperature and water content on the growth and stress response of creeping bentgrass(Agrostis palustris Huds.) under a humid and warm temperature. USGA(United State of Golf Association) green profile in laboratory test, Daily temperature changes were tested under a dried sand, 70% water content of field capacity, and saturated condition at 34℃ of the USGA green in lab. In this test, the dried sand reached to 80oC, however, the surface temperature decrease of 10oC on the saturated condition. In the thermal properties test in field, thermal conductivity, thermal diffusivity, and soil temperature were increased followed by irrigation practise. In the water-deficient condition, the highest soil temperature was reached temporally right after irrigation, however, the excessive soil water content higher than field water holding capacity showed the highest soil temperature after a while. This result indicated that a heat damage to root system was caused from the thermal conductivity of a high surface soil temperature. The excessive irrigation when a high turf surface temperature should occur a negative result on tufgrass growth, moreover, it would be fatal to root growth of creeping bentgrass, especially when associated with a poor draining system on USGA sand green. Overall, this study shows that high soil temperature with water-excessive condition negatively affects on cool-season grass during the summer season, suggesting that excessive irrigation, over 70% field capacity of soil condition, does not help to reduce soil temperature for summer season in Korea. In the study that cool-season grass were treated with different water content of soil, The soil had higher temperature and more water holding capacity when treatment rate of soil conditioner was increased. The best growth at the normal water condition and the worst state of growth at thee water-excessive condition were observed. 여름철 고온 다습한 우리나라 기온에서 토 양 온도와 수분은 잔디의 생리학적 변화를 초 래하며, 특히 한지형 잔디생육은 우리나라 여 름철 기후의 특이성에 많은 영향을 받는다. 본 실험은 크리핑 벤트그래스(Agrostispalustris Huds.)를 이용하여 고온의 조건에서 각기 다 른 토양 수분함량 조건에서의 한지형 잔디생 육을 관찰하였다. 구체적인 실험 방법으로는 수분함량과 온도에 따른 bentgrass의 생육 및 생리적 스트레스 반응을 평가하였다. 모의 USGA(United State of Golf Association) 그린 조건에서의 토양 온도 및 열 특성 실험 결과 수분이 거의 없는 건조 상태에서의 토양 온도는 34℃로 발열 했을 때 토양 표면 온도 가 80℃까지 올라가는 것을 알 수 있었다. 반면, 과수분 조건에서 34℃ 발열을 했을 때에 는 건조 조건에 비해 상대적으로 10℃가 낮은 것을 알 수 있었다. 실험 포장에서의 온도와 수분에 따른 열 특성 변화는 관수시기와 무관 하게 처리구 모두에서 관수 후에 열전도도 (thermal conductivity), 열 확산성(thermal diffusivity), 및 토양 온도가 증가하였다. 이는 수분이 공기에 비해 상대적으로 높은 열전도 도를 갖기 때문으로 사료된다. 또한, 본 실험 에서 관수 초기에는 과수분 조건에 비해 수분 결핍 조건에서 토양 온도의 증가를 보였으며, 시간이 지남에 따라 과수분 조건에서 더 높은 토양 온도의 증가를 확인하였다. 즉, 토양 온 도는 과수분 조건에서 열전도에 의해 높아져 잔디의 생육에 영향을 미친다. 이는 잔디 표면 부 온도가 높은 시각대의 과도한 관수는 여름 철 잔디의 생육에 부정적 영향을 미치며, 소나 기 등에 의한 일시 침수 시 지반배수의 불량 은 잔디 생육에 치명적인 요인이 될 수 있다 는 것을 의미한다.