• 제목/요약/키워드: aging

검색결과 9,993건 처리시간 0.038초

Incorporating Station Related Aging Failures in Bulk System Reliability Analysis

  • Billinton Roy;Yang Hua
    • KIEE International Transactions on Power Engineering
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    • 제5A권4호
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    • pp.322-330
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    • 2005
  • This paper proposes methods to incorporate station related aging failures in composite system reliability assessment. Aging failures of station components, such as circuit breakers and bus bars, are a major concern in composite power system planning and operation as an increasing number of station components approach the wear-out phase. This paper presents probabilistic models for circuit breakers involving aging failures and relevant evaluation techniques to examine the effects of station related aging outages. The technique developed to incorporate station related aging failures are illustrated by application to a small composite test system. The paper illustrates the effects of circuit breaker aging outages on bulk system reliability evaluation and examines the relative effects of variations in component age. System sensitivity analysis is illustrated by varying selected component parameters. The results show the implications of including component aging failure considerations in the overall analysis of a composite system.

대학생의 노화 지식, 노인에 대한 태도 및 노인 부양 의식 (A study on Aging Knowledge, Attitudes and Awareness about Supporting the Aged in Undergraduate Students)

  • 양야기
    • 한국간호교육학회지
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    • 제19권4호
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    • pp.498-507
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    • 2013
  • Purpose: This study was conducted to investigate the relationship of aging knowledge, attitudes and awareness about supporting the aged in undergraduate students. Method: The participants were 385 undergraduate students in H University in G city. Data were collected from March 1 to April 30, 2012, and analyzed using SPSS/WIN 18.0. Results: The mean of the aging knowledge score was 51.40, the mean of aging attitudes score was 3.06, and the mean of awareness about supporting the aged score was 4.11. Awareness about supporting the aged showed a positive correlation with aging knowledge (r=.299, p<.001). Awareness about supporting the aged showed a positive correlation with aging attitudes (r=.244, p<.001). Conclusion: The findings of this study indicate a need to develop programs for undergraduate students to increase correct aging knowledge, to encourage appropriate aging attitudes and awareness about supporting the aged. In addition, the need for further studies to examine effects of programs are needed.

PZT 압전세라믹스 공진자의 공진주파수의 경시변화 (Aging of Resonant Frequency of PZT Piezoelectric Ceramic Resonantors)

  • 이개명;강찬호;김병효;황충구;고승우
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
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    • pp.109-114
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    • 2002
  • Aging stabilities of the operating frequency of piezoelectric devices such as filter, oscillator and discriminator are very important. In this study it was studied aging stabilities of the length-extensional vibration mode of Pb(Zr$\_$y/Ti$\_$1-y/)O$_3$+x[wt%]Cr$_2$O$_3$ ceramics. PZT ceramics in Morphotropic phase boundary have higher aging rates of k$\_$31/ and resonant frequency than those in tetragonal phase or rhombohedral phase. Thermal aging moves the composition with maximum aging rate to Zr-rich side in Cr not added PZT system. Aging rate of resonant frequency of the ceramics with x=0.1, y=0.53 and x=0.3, y=0.53 increased by thermal aging.

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22.9 kV CV 전력케이블의 14주기 고온 열화에 대한 Lightning-Impulse 특성 (Lightning Impulse Characteristics for 22.9 kV CV Power Cable Before and After Cyclic Aging for 14days)

  • 김위영;윤대혁;박태곤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1549-1551
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    • 2001
  • Cyclic aging for 14 days is performed to remove a large amount of the volatiles found in freshly manufactured cable. In this paper, we examined lightning impulse characteristics of 22.9 kV CV power cable before and after cyclic aging for 14days. As the result, the breakdown voltage after aging under normal temperature was lower than that before aging, and the breakdown voltage after aging under hot temperature was lower than that before aging. We found that the dispersion of lightning impulse breakdown voltage before 14 cyclic aging test were reduced rather than those after 14 cyclic aging test.

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고령사회 대응 연구개발 지원방안 연구 (A Study on R&D program for the aging society)

  • 유재성
    • 대한안전경영과학회지
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    • 제18권3호
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    • pp.109-116
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    • 2016
  • The purpose of this study is to explore the research and development(R&D) programs for effectively response of population aging. We analyzed of aging-related R&D support status by National Science and Technology Information Services(NTIS) and reviewed of foreign aging-related R&D programs. It was found that the overall lack of support systems, the R&D support status for Korea's aging society is very low performance and the difference appears in the annual support status, etc. It is very important to enhance the effectiveness of R&D programs in order to effectively prepare for aging society. I suggested support measures of the R&D for aging society by survey research. The result of this study will help in planning of the R&D for aging society and contribute to increasing of welfare for the aged.

How Environmental Agents Influence the Aging Process

  • Karol, Meryl H.
    • Biomolecules & Therapeutics
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    • 제17권2호
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    • pp.113-124
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    • 2009
  • Aging is a multifaceted biological process that affects all organs and organ systems of the body. This review provides an up-to-date analysis of this highly exciting, rapidly changing field of science. The aging process is largely under genetic control but is highly responsive to diverse environmental influences. The genes that control aging are those that are involved with cell maintenance, cell damage and repair. The environmental factors that accelerate aging are those that influence either damage of cellular macromolecules, or interfere with their repair. Prominent among these are chronic inflammation, chronic infection, some metallic chemicals, ultraviolet light, and others that heighten oxidative stress. Other environment factors slow the aging process. Included among these agents are resveratrol and vitamin D. In addition, dietary restriction and exercise have been found to extend human lifespan. The various mechanisms whereby all these agents exert their influence on aging include epigenetic modification, chromatin maintenance, protection of telomeres, and anti-oxidant defense, among others. The complex process of aging remains under continued, intense investigation.

Thermal aging effect on fracture toughness of GTAW/SMAW of 316L stainless steel: experiments and applicability of existing CASS models

  • Youn, Gyo-Geun;Kim, Yun-Jae;Miura, Yasufumi
    • Nuclear Engineering and Technology
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    • 제53권4호
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    • pp.1357-1368
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    • 2021
  • This paper presents thermal aging effect on fracture toughness properties of GTAW (gas tungsten arc welding) and SMAW (shielded metal arc welding) of 316L stainless steels, and investigates the applicability of the existing three thermal aging models for CASS (cast stainless steels). Thermal aging was carried out at 350 ℃ for up to 15,000h and at 400 ℃ up to 8,000h. After aging, tensile and fracture toughness tests using 0.5T C(T) specimens were carried out at room temperature and at 288 ℃. Comparing with the predictions using three (ANL, French and H3T) thermal aging models for CASS show that the predictions can be very non-conservative at operating temperature, and thus that the existing thermal aging models for CASS cannot be applied to the welded stainless steels.

Recent Progress in Regulation of Aging by Insulin/IGF-1 Signaling in Caenorhabditis elegans

  • Lee, Hanseul;Lee, Seung-Jae V.
    • Molecules and Cells
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    • 제45권11호
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    • pp.763-770
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    • 2022
  • Caenorhabditis elegans has been used as a major model organism to identify genetic factors that regulate organismal aging and longevity. Insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) regulates aging in many species, ranging from nematodes to humans. C. elegans is a nonpathogenic genetic nematode model, which has been extensively utilized to identify molecular and cellular components that function in organismal aging and longevity. Here, we review the recent progress in the role of IIS in aging and longevity, which involves direct regulation of protein and RNA homeostasis, stress resistance, metabolism and the activities of the endocrine system. We also discuss recently identified genetic factors that interact with canonical IIS components to regulate aging and health span in C. elegans. We expect this review to provide valuable insights into understanding animal aging, which could eventually help develop anti-aging drugs for humans.

Changes in free amino acid content and hardness of beef while dry-aging with Mucor flavus

  • Hanagasaki, Takashi;Asato, Naokazu
    • Journal of Animal Science and Technology
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    • 제60권7호
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    • pp.19.1-19.10
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    • 2018
  • Background: A mold strain thought to be suitable for dry-aging process was isolated. The information about the scientific aspects of molds related to dry-aging beef is scarce. We, therefore, conducted aging trials to determine the characteristics of the isolated mold strain associated with dry-aging process. Specifically, during the dry-aging of beef with the mold strain, the changes in the free amino acid content, hardness, productive loss, drip and cooking loss were analyzed. These characteristics were compared with those obtained while dry-aging in the absence of a mold. Results: The isolated mold strain was identified as Mucor flavus. The free amino acid content in the mold-aging beef decreased or remained constant during the aging process. However, that in the trimming sections of the beef dramatically increased in the presence of mold. In addition, hardness of mold-aging beef gradually decreased during the aging process and finally decreased significantly. Conclusion: Amino acids such as GABA (gamma-aminobutyric acid), proline, and aspartic acid were produced by our mold strain, M. flavus during its growth on beef meat, and the mold conferred savory odors to the dry-aged beef.

The Dilemmas of Aging and Down-aging : The Fashion Attitude of Senior Street Look

  • Ro, Juhyun;Park, Juhee
    • International Journal of Costume and Fashion
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    • 제17권1호
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    • pp.59-72
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    • 2017
  • This study aimed to analyze the dilemmas of aging and down-aging by the senior street look, and to examine the styling, psychology, and attitudes of the elderly through socio-cultural discussions. It was conducted through a multidisciplinary literature review and empirical analysis of seniors featured in fashion photos collected from SNS. With respect to seniors' fashion attitudes, firstly, they make personal/social records of dress as a means of recording aging and to reminiscence. Secondly, they attempt to down-age kidult play using mature humor. Thirdly, they try to express a perfect, moderate, and mature beauty to positively adapt themselves to aging. Fourthly, they adopt a regional and ethnic look to escape from the dilemmas accompanying aging and down-aging. This may be regarded as an attitude for repositioning themselves and planning a new life by escaping from a long-standing frame. Finally, they show a desire to stop and enjoy the moment of aging. While recording their cherished everyday lives, they enjoy the present rather than becoming concerned about the past or the future and use styling as a cure for their lives.