• 제목/요약/키워드: ageing characteristics

검색결과 163건 처리시간 0.022초

철근 부식을 고려한 교량의 지진취약도 평가 (Seismic Fragility Evaluation of Bridges Considering Rebar Corrosion)

  • 신수봉;꽁씨나;문지호;송종걸
    • 한국전산구조공학회논문집
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    • 제34권4호
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    • pp.231-241
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    • 2021
  • 교량의 노후화는 다양한 원인에 기인하겠지만 겨울철에 제설용으로 살포하는 염화칼슘이 교량부재에 침투하여 부식을 유발하는 것이 대표적인 교량 노후화 원인중 하나라고 할 수 있다. 본 연구의 목적은 교량의 부식에 의한 노후화 정도를 정량화하고 이를 교량의 해석모델에 적용하여 노후화 정도에 따른 지진취약도 해석을 수행하고 노후화 정도와 지진취약도 곡선의 관계를 평가하는 것이다. 노후화 정도를 고려한 지진취약도 해석에 각 손상상태별로 한계값을 적절히 정의하는 것이 중요하다. 본 연구에서는 손상정도에 따른 변위 연성도 능력의 저하 특성에 관한 기존 연구결과를 활용하여 손상상태를 정의하였다. 세 가지 교량받침과 두 가지 교각 높이에 따른 예제 교량들의 지진취약도 해석으로부터 노후화 정도가 증가할수록 지진취약도가 증가하는 경향이 나타냄을 알 수 있다. 이러한 노후화 정도에 따른 지진취약도의 차이는 손상상태가 경미, 보통, 심각, 붕괴의 상태로 갈수록 증가하는 경향을 나타낸다.

아일랜드 '주택을 위한 유니버설디자인 가이드라인'의 사용자 혜택 특성 연구 (User Benefit Characteristics of Universal Design Guidelines for Homes in Ireland)

  • 이연숙;안소미;현지원;박재현
    • 한국실내디자인학회논문집
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    • 제26권2호
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    • pp.72-82
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    • 2017
  • Current world population is rapidly ageing and the disabled population is expected to age seriously as well. The concern about the elderly and the disabled is increased largely not just the field of social welfare and service but the housing planning where the physical environment of everyday life is. Recently in Ireland, 'Universal Design Guideline for Homes' is established and proposed in public. It is considered as initial and special national policy for the socially venerable. The purpose of this research is to analyze the User Benefit Characteristics(UBC) of 'Universal Design Guideline for Homes in Ireland' and clearly organize the characteristics for comprehensive communication. The research subjects are 444 guidelines of 'Universal Design Guideline for Homes in Ireland.' The research is conducted by contents analysis technique, and each guideline is analyzed by the 4 main concepts of UBC- 'Behavioral Facilitation(BF)', 'Physiological Maintenance(PhM)', 'Perceptual Maintenance(PM)', 'Social Facilitation(SF).' As results, the User Benefit Characteristic of 'Universal Design Guideline for Homes in Ireland' is ordered by PhM>PM>BF>SF. The design guidelines are supposed to support ageing in place and sustainable living in the existing houses even though people are ageing or being disabled. 'Universal Design Guideline for Homes in Ireland' supports safe behavior and comfort cognition especially in indoor and surrounding outdoor environment. This research is significant for sharing the knowledge and comprehension of decreasing environmental stress of the elderly in specific, and could be utilized for developing new elderly housing in future.

열처리 인공촉진열화가 배접지의 광학적 및 기계적 특성에 미치는 영향 (Optical & Mechanical Characteristics of Lining Papers by the Artificial Heat Ageing Treatment)

  • 정선화;최경화;박지희;강영석;윤경동
    • 보존과학연구
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    • 통권30호
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    • pp.93-102
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    • 2009
  • This study was carried out to investigate the effect of artificial accelerated ageing treatment on the permanence of lining papers produced from Korea and Japan. As time gone by, organic cultural properties are affected by chemical and physical deterioration because of various factors including the conditions of preservation environment and their material properties. In the public historical storage or owned as private collections, are vulnerable to sever amages caused by poor preservation environment as well as by other natural factors. In this study, the deterioration behaviors of lining paper in optical & mechanical properties were discussed. Overall, lining papers produced from Korea showed lower reduction in mechanical strength properties compared to the lining papers produced from Japan.

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Comparative Study of DC Breakdown and Space Charge Characteristics of Insulation Paper Impregnated with Natural Ester and Mineral Oil

  • Hao, Jian;Zou, Run-Hao;Liao, Rui-Jin;Yang, Li-Jun;Liao, Qiang;Zhu, Meng-Zhao
    • Journal of Electrical Engineering and Technology
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    • 제13권4호
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    • pp.1682-1691
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    • 2018
  • Natural ester is a suitable substitute for mineral oil and has been widely used in AC transformer in many countries. In order to further application of natural ester in direct current (DC) equipment, it is needed to investigate its long term insulation property under DC condition. In this paper, a thermal ageing experiment was conducted for both mineral oil-paper and natural ester-paper insulation. The DC breakdown and space charge characteristics of insulation paper impregnated with natural ester and mineral oil was compared. Results show that the resistivity of the paper immersed in natural ester and mineral oil both increase as the ageing goes on. While insulation paper impregnated with natural ester has higher resistivity and DC breakdown voltage than the paper impregnated with mineral oil. The DC breakdown voltage for the oil impregnated insulation paper being DC pre-stressing is higher than that without pre-stressing. The average DC breakdown field strength difference between the test with pre-stressing and without pre-stressing clearly shows that there is an apparent enhancement effect for the homo-charge injection on the DC breakdown.

EPDM 및 실리콘 재질의 폴리머현수애자의 특성 비교 (The Comparison of EPDM and Silicone in Housing Materials of Polymeric Suspension Insulators)

  • 이병성;이재봉;송일근;한상옥
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마연구회
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    • pp.6-10
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    • 2003
  • In our country, the housing materials of polymeric outdoor insulators have mainly been used EPDM or silicone rubber. EPDM housing materials had been widely used in the field for the first time. The reason why silicone has the high cost of production. But recently, most of the manufacturers that newly developed polymeric insulators make its choice of silicone housing. EPDM showed a good resistance to tracking. We compared the various characteristics for EPDM and silicone insulators that have similar type and design. Silicone insulators have more performance in flashover voltage test and leakage current measurement because of a good water repellent than EPDM ones. Also, the property of EPDM compared with silicone insulators greatly decreased after aging test in combined acceleration ageing facilities for 1000 hours.

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흡수열화에 따른 Epoxy/$SiO_2$ 복합체의 전기적 특성 및 수명예측 (Electrical Properties and Lifetime Prediction of Epoxy/$SiO_2$Composites with Water Absorption Ageing)

  • 김탁용;이덕진;홍진웅
    • 한국전기전자재료학회논문지
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    • 제13권9호
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    • pp.758-763
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    • 2000
  • Dielectric strength of insulators made of epoxy composites rapidly decreases due to ageing to interfaces between the matric resin and filler particles. The adhesion variation of interfaces caused by moisture absorption also alters electrical properties that are the basic characteristics of insulators, particularly, in outdoor use. In this paper, electrical properties of epox/SiO$_2$composites were investigated at boiling absorption condition to observe the influences of moisture. In order to analyze the basic physical properties of samples, scanning electron microscopy and DC, AC and impulse voltage dielectric strength were measured. Also, the breakdown time of samples was measured under AC 6[kV] applied voltage, and the variation of lifetime was verified by using Weibull distribution function.

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Application of particle filtering for prognostics with measurement uncertainty in nuclear power plants

  • Kim, Gibeom;Kim, Hyeonmin;Zio, Enrico;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • 제50권8호
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    • pp.1314-1323
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    • 2018
  • For nuclear power plants (NPPs) to have long lifetimes, ageing is a major issue. Currently, ageing management for NPP systems is based on correlations built from generic experimental data. However, each system has its own characteristics, operational history, and environment. To account for this, it is possible to resort to prognostics that predicts the future state and time to failure (TTF) of the target system by updating the generic correlation with specific information of the target system. In this paper, we present an application of particle filtering for the prediction of degradation in steam generator tubes. With a case study, we also show how the prediction results vary depending on the uncertainty of the measurement data.

가스분사법으로 제조된 Mg-6 wt.% Al-1 wt.% Zn 합금의 시효특성 (The Aging Characteristics of Mg-6 wt.% Al-1 wt.% Zn Alloy Prepared by Gas Atomization)

  • 이두형;김보식;장시영
    • 한국분말재료학회지
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    • 제16권4호
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    • pp.275-279
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    • 2009
  • The aging characteristics of gas atomized Mg-6 wt.% Al-1 wt.% Zn alloy were investigated and compared to those of cast Mg-6 wt.% Al alloy. The gas atomized Mg-6 wt.% Al-1wt.% Zn alloy powders had spherical morphology between 1 and 100 $\mu m$ in diameter. After compaction under the pressure of 700 MPa at $320^{\circ}C$ for 10 min, the Mg-6 wt.% Al-1 wt.% Zn alloy showed a grain size of approximately 40 $\mu m$ which is smaller than that of the cast Mg-6 wt.% Al alloy, and a relative compact density of approximately 93%. After ageing, the Mg-6 wt.% Al-1 wt.% Zn alloy showed much faster peak hardness than cast Mg-6 wt.% Al alloy. The Mg-6 wt.% Al-1 wt.% Zn alloy showed the new fine precipitations with ageing time, while the cast Mg-6 wt.% Al alloy was almost similar morphology.

국내 노인생애체험전시관 공간구성에 관한 분석 연구 (Study on Space Composition Analysis of the Local Old Age Experience Hall)

  • 조정미;김문덕
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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    • pp.173-178
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    • 2006
  • An increase in the proportion of Korean population in older age is much faster than the rest of the world. Along with rise of nuclear family due to rapid industrialization, informatization and materialization, ageing, on current situation in Korea that a reality of being diminished consciousness involving the sense of filial piety, and of respect or honor for the elders, does mean that such topics in ageing have become sociocultural issues that a nation should get more deeply involved in caring later life of the elderly population in an official and obligatory manner. Under this circumstance, an exhibition space in the hall intended for experiencing the later life of the elderly will surely play the role of locomotive in the respect of education to understand aging adults, and to promote development of health and welfare industry, especially for older population, also in creating and developing a positive and desirable culture and environment. To implement design project concerned with the space for the elderly population in a more careful and effective manner, the features of the Old Age Experience Hall that will satisfy the requirements thereof and the space compositions as well as characteristics of three exhibition halls having already been operated were analyzed examining closely the current facing issues in this aging society and also investigating the aging process related to physical functions of older adults. Based on those analyses, this study was aimed to prepare an efficient and systematic theoretical foundation for planning space composition of the Old Age Experience Hall further having extracted basic directions for design from, which should be meticulously considered and reflected so as to make the Old Age Experience Hall function properly.

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