• 제목/요약/키워드: influence of isolation method

검색결과 34건 처리시간 0.022초

Dynamic assessment of the seismic isolation influence for various aircraft impact loads on the CPR1000 containment

  • Mei, Runyu;Li, Jianbo;Lin, Gao;Zhu, Xiuyun
    • Nuclear Engineering and Technology
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    • 제50권8호
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    • pp.1387-1401
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    • 2018
  • An aircraft impact (AI) on a nuclear power plant (NPP) is considered to be a beyond-design-basis event that draws considerable attention in the nuclear field. As some NPPs have already adopted the seismic isolation technology, and there are relevant standards to guide the application of this technology in future NPPs, a new challenge is that nuclear power engineers have to determine a reasonable method for performing AI analysis of base-isolated NPPs. Hence, dynamic influences of the seismic isolation on the vibration and structural damage characteristics of the base-isolated CPR1000 containment are studied under various aircraft loads. Unlike the seismic case, the impact energy of AI is directly impacting on the superstructure. Under the coupled influence of the seismic isolation and the various AI load, the flexible isolation layer weakens the constraint function of the foundation on the superstructure, the results show that the seismic isolation bearings will produce a large horizontal deformation if the AI load is large enough, the acceleration response at the base-mat will also be significantly affected by the different horizontal stiffness of the isolation bearing. These concerns require consideration during the design of the seismic isolation system.

벽체 우회전달음 영향요소에 관한 연구 (A Study on the factor of flanking transmission in the Wall)

  • 정진연;이성호;김경우
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 추계학술대회논문집
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    • pp.380-383
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    • 2006
  • This study examines the influence factor of flanking transmission in the wall. Generally, there is the difference of airborne sound isolation between laboratory and field test. The purpose of this study is examing the cause of droping sound insulation performance in the field and searching the method of improving sound insulation performance. First, we measured the sound isolation in the wall at the lab. Then, we measured it in the field and compared them. At the base of these datum, we measured the flanking transmission and solid transmission. For the flanking transmission am the wall, we used intensive method. So, we found the influence of solid transmission.

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벽체 우회전달음 영향요소에 관한 연구 (A Study on the Factor of Flanking Noise in the Wall)

  • 정진연;정갑철
    • 한국소음진동공학회논문집
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    • 제17권2호
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    • pp.143-148
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    • 2007
  • This study examines the influence factor of flanking noise in the wall. Generally, there is the difference of airborne sound isolation between laboratory and field test. The purpose of this study is examing the cause of droping sound insulation performance in the field and searching the method of improving sound insulation performance. First, we measured the sound isolation in the wall at the lab. Then, we measured it in the field and compared them. At the base of these datum, we measured the flanking noise and solid transmission. For the flanking noise in the wall, we used intensive method. So, we found the influence of solid transmission.

관성센서의 이중 고장을 고려한 고장 검출 및 분리 (FDI considering Two Faults of Inertial Sensors)

  • 김광훈;박찬국;이장규
    • 제어로봇시스템학회논문지
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    • 제10권1호
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    • pp.1-9
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    • 2004
  • Inertial navigation system with hardware redundancy must use FDI(Fault Detection and Isolation) method to remove the influence of faulty sensors. Until now, several FDI methods such as PSA(Parity Space Approach), GLT(Generalized Likelihood ratio Test) and OPT(Optimal Parity vector Test) method are generally used. However, because these FDI methods only consider the situation that the system has one faulty sensor, these methods cannot be directly adapted for the system with two faulty sensors. To solve this problem, in this paper, PSA method is analyzed and based on this result, new FDI method called EPSA is proposed to consider a detection and an isolation of two faulty sensors in inertial navigation system.

LRB와 슬라이딩베어링을 혼용한 면진시스템을 적용한 아파트 건물의 지진 응답 (Seismic Response of Apartment Building with Base Isolation System Consisting of Sliding-type Bearing and Lend Rubber Bearing)

  • 천영수;윤영호;황기태;장극관
    • 콘크리트학회논문집
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    • 제19권4호
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    • pp.507-514
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    • 2007
  • 이 논문은 기존 내진설계와 비교하여 면진설계의 효용성과 경제적 효과에 대한 연구 결과를 정리한 것이며, 면진설계에 있어서는 납봉삽입적층고무베어링 (LRB)만을 사용한 경우와 비교하여 슬라이딩베어링과 LRB를 혼용한 면진시스템의 내진 거동을 함께 제시하였다. 연구 결과, 면진은 구조물에 대하여 지진동으로 인한 효과를 감소시키는데 매우 효과적이며, 층 가속도의 감소로 사용성을 증가시킬 수 있음이 입증되었다. 또한 층 가속도와 밑면 전단력의 감소라는 관점에서 슬라이딩베어링과 LRB를 혼용한 면진시스템이 LRB만을 사용한 경우보다 더 효과적임을 증명하였다. 하지만 경제적 효과 면에서는 증가된 성능에 비례하여 지불해야만 하는 비용도 커진다는 사실에 특별히 주의할 필요가 있는 것으로 나타났다.

Evaluation and Characterization of Milk-derived Microvescicle Isolated from Bovine Colostrum

  • Maburutse, Brighton E.;Park, Mi-Ri;Oh, Sangnam;Kim, Younghoon
    • 한국축산식품학회지
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    • 제37권5호
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    • pp.654-662
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    • 2017
  • Extracellular microvesicles are membranous nano-sized cellular organelles secreted by a variety of cells under normal and pathological conditions and heterogeneous in size ranging from 30 nm to $1{\mu}m$. They carry functional microRNAs that can influence immunity and development. For a particular application of microvesicles, choice of isolation method is particularly important; however, their isolation methods from colostrum in particular have not been described clearly. In this work, differential ultracentrifugation as a conventional method, ultracentrifugation with some modification such as additional precipitations, ultrafiltration, sucrose gradient separation and ExoQuick$^{TM}$ as a commercial reagent were compared. The goal was to compare mainly microvesicular total microRNA yield, distribution and purity among the methods then select the best isolation method for bovine colostrum microvesicles based largely on microRNA yield with the view of applying the vesicles in work where vesicular microRNA cargo is the target bioactive component. Highest yields for vesicular microRNA were obtained using conventional methods and among them, subsequent ultracentrifugation with 100,000 g and 135,000 g conventional method 2 was selected as it had the highest RNA to protein ratio indicating that it pelleted the least protein in relation to RNA an important factor for in vivo applications to assess microvesicle functionalities without risk of contaminating non-vesicular biomaterial. Microvesicles isolated using conventional method 2 were successfully internalized by cells in vitro showing their potential to deliver their cargo into cells in vitro and in vivo in case of functional studies.

살구의 휘발성 성분 조성에 대한 분리방법의 영향 (Influence of Isolation Method on the Composition of Apricot (Prunus armeniaca var. ansu Max.) Flavor)

  • 김영회;곽재진;권영주;양광규
    • 한국식품과학회지
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    • 제22권5호
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    • pp.543-548
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    • 1990
  • 살구의 휘발성 향기성분 조성에 대한 분리 방법의 영향을 조사코저 살구 과육(pH 3.1)을 simultaneous distillation-extraction(SDE)법, headspace trapping법 또는 이를 pH 7.0으로 중화시킨 후 SDE법에 의해 얻어진 정유성분의 조성을 분석 비교하였다. GC-MS 및 GC에 의한 표준품과 머무름 시간의 비교에 의해 확인된 80종의 성분들 중 pH3.1에서 SDE법에 의해 얻어진 정유성분중에는 다른 두 가지 방법에 의해 얻어진 정유성분에서는 검출되지 않거나 또는 미량으로 검출된 n-hexanal, trans-2-hexenal, cis-3-hexen-1-ol, linalool oxide, linalool, ${\alpha}-terpineol$, nerol, geraniol, benzyl alcohol, ${\beta}-phenylethyl alcohol$ 및 naphthalene 유도체들이 많이 검출되었으며 이러한 결과는 살구에서 비휘발성인 glycoside 형태로 존재하는 위와 같은 성분들이 산성조건하에서 수증기 증류시 glycoside 결합이 가수분해되어 휘발성 성분으로 유리되는데 기인하는 것으로 판단되었다.

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한국 청소년 비행의 성차 분석 (Gender Difference in Delinquent Behavior among Korean Adolescents)

  • 김현실
    • 대한간호학회지
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    • 제32권4호
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    • pp.492-505
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    • 2002
  • This paper examined gender differences in a rate, type, relevant variables of delinquent behavior, and a gender differences regarding the relative influence of family, personality, academic achievement, sexual abuse and alcohol .drug abuse on delinquent behavior among Korean adolescents. Method: Data were collected by self-report questionnaires. Subjects consisted of 2,100 adolescents (male 1,396, female 704) in Korea, using proportional stratified random sampling method. Statistical methods were Chi-square, t-test and path analysis. Result: Male adolescents had higher rate of delinquent behavior, and more all types of delinquent behavior (antisocial, aggressive, and psychopathic) than female. Male adolescents showed more dysfunctional family dynamic environments, higher antisocial personality and sociability than female adolescents. Female adolescents had higher depressive tendencies than male. The most powerful contributing variables on male delinquent behavior were age, antisocial personality, parent-child relationship, isolation feelings, and sexual abuse in this order named. Drug abuse, isolation feelings, antisocial personality and parent-child relationship tended to be contributing variables for female delinquent behaviors in this order named. Conclusion: This investigation will provides a foundation for theory that addresses the complexities of both gender-specific and gender influences on delinquent behavior and development of preventive strategies for female delinquency.

Cable anomaly detection driven by spatiotemporal correlation dissimilarity measurements of bridge grouped cable forces

  • Dong-Hui, Yang;Hai-Lun, Gu;Ting-Hua, Yi;Zhan-Jun, Wu
    • Smart Structures and Systems
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    • 제30권6호
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    • pp.661-671
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    • 2022
  • Stayed cables are the key components for transmitting loads in cable-stayed bridges. Therefore, it is very important to evaluate the cable force condition to ensure bridge safety. An online condition assessment and anomaly localization method is proposed for cables based on the spatiotemporal correlation of grouped cable forces. First, an anomaly sensitive feature index is obtained based on the distribution characteristics of grouped cable forces. Second, an adaptive anomaly detection method based on the k-nearest neighbor rule is used to perform dissimilarity measurements on the extracted feature index, and such a method can effectively remove the interference of environment factors and vehicle loads on online condition assessment of the grouped cable forces. Furthermore, an online anomaly isolation and localization method for stay cables is established, and the complete decomposition contributions method is used to decompose the feature matrix of the grouped cable forces and build an anomaly isolation index. Finally, case studies were carried out to validate the proposed method using an in-service cable-stayed bridge equipped with a structural health monitoring system. The results show that the proposed approach is sensitive to the abnormal distribution of grouped cable forces and is robust to the influence of interference factors. In addition, the proposed approach can also localize the cables with abnormal cable forces online, which can be successfully applied to the field monitoring of cables for cable-stayed bridges.

Influence of the deteriorated anti-seismic devices on seismic performance and device behavior of continuous girder bridges

  • Shangtao Hu;Renkang Hu;Menggang Yang;Dongliang Meng
    • Earthquakes and Structures
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    • 제24권5호
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    • pp.333-343
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    • 2023
  • Various seismic isolation and reduction devices have been applied to suppress the longitudinal vibration of continuous girder bridges. As representative devices, lead rubber bearing (LRB) and fluid viscous damper (FVD) might suffer from deterioration during the long-term service. This study aims to evaluate the impact of device deterioration on the seismic responses of continuous girder bridges and investigate the seismic behavior of deteriorated LRBs and FVDs. Seismic performance of a simplified bridge model was investigated, and the influence of device deterioration was evaluated by the coefficient of variation method. The contribution of LRB and FVD was assessed by the Sobol global sensitivity analysis method. Finally, the seismic behaviors of deteriorated LRBs and FVDs were discussed. The result shows that (i) the girder-pier relative displacement is the most sensitive to the changes in the deterioration level, (ii) the deterioration of FVD has a greater effect on the structural responses than that of LRB, (iii) FVD plays a major role in energy dissipation with a low degradation level while LRB is more essential in dissipating energy when suffering from high degradation level, (iv) the deteriorated devices are more likely to reach the ultimate state and thus be damaged.