• 대한안전경영과학회지
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• 제16권4호
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• pp.133-145
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• 2014

Aging of the fire organizations, typical disaster response agencies also will be in serious problems with aging society. It is expected that the ratio of more than fifties will reach 31~40% after 10~15 years in Seoul fire organization. This Aging of firefighters can bring about a serious problem in disaster and safety management, since firefighters require robust fitness and healthy bodies in disaster situations. In this study, after the analysis of aging status and trend of firefighters in Seoul, I have an empirical analysis about the impact this aging has on organization effectiveness and QA. As a result, the increase of the elderly reduced organization effectiveness and QA. In addition, in the group consisting of less than 50, it is expected to increase the organization's effectiveness and QA activities through field activity to improve the professional skills with age, but could not be confirmed. In the group consisting of more than fifties, it was found that aging had a significant negative impact on organizational effectiveness and QA activities as factors, including physical deterioration by aging.

• 한국전기전자재료학회논문지
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• 제24권10호
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• pp.803-806
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• 2011

1 mol% $Li_2O$ excess $0.9(Na_{0.52}K_{0.48})NbO_3-0.1LiTaO_3$ lead-free piezoelectric multilayer ceramic actuators were investigated to determine their aging properties. To reduce the thermal aging behavior, we applied a rectified unipolar electric field of 5 kV/mm to the specimen to accelerate the electric aging behavior. By employing a rectified unipolar electric field for the piezoelectric actuators, we could remove undesirable heating from the relaxation current in the motion of the ferroelectric domain. To accelerate the aging test, the applied electric fields had a frequency of 900 Hz. To have enough time for charging and discharging, we employed an accurate time constant to design the equivalent circuit model for the aging tester. To extract exact aging behavior, we measured the pseudo-piezoelectric coefficient before and after the aging process. We also measured the electro-mechanical coupling coefficient, the frequency-dependent dielectric permittivity, and the impedance to compare with fresh and aged specimen.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.522-525
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• 1999

The electrical characteristics of 3 year field-aged polymer insulators which dismounted from five regions were investigated. There was a little difference in PD inception voltage depending on the manufacturers and the regions. The results between PD and SD showed a close relation. There were no significant changes in electrical properties. So, it can be considered that the field-aged insulators are sound for the present.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.782-785
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• 2007

We studied the effect of current-aging on field emission from carbon nanotubes field emitter arrays (CNT-FEAs) selectively patterned by the resist-assistan tpatterning(RAP) process. After sustaining the electric field when starting emission current density $(J_s)$ is $0.1\;mA/cm^2$ during 40 hrs, it was observed that the field emission property and uniformity were remarkably improved due to the elimination of oxygen atom and thus the reconstruction of carbon bonding at the tip of CNTs during field emission.

• 한국지반공학회논문집
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• 제20권6호
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• pp.137-150
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• 2004

모래의 aging 현상은 점성토에 비하여 무시할 정도로 매우 작아서 최근까지 연구되지 않았다. 그러나 퇴적이나 교란 후 시간경과에 따라 관입저항치의 증가가 관찰되면서 현장시험을 중심으로 모래의 aging 효과에 대하여 활발한 조사가 이루어졌고, 최근에는 현장시험뿐만 아니라 실내시험에서도 여러 연구자들에 의해 모래의 aging 효과가 규명 되어지고 있다. 본 연구에서는 모래의 비배수 정적전단거동에 대한 aging 효과를 살펴보기 위해 낙동강 모래를 이용하여 상대밀도 $(D_r)$, 압밀응력비$(K_c)$ 그리고 압밀시간을 달리하여 비배수 정적삼축압축시험을 실시하였다. 그 결과 응력-변형률의 탄성구간내 탄성계수가 압밀시간 경과에 따라 증가하는 것으로 나타났으며, 또한 상전이점 강도$(S_{PT})$와 한계응력비점 강도$(S_{CSR})$도 압밀시간 경과에 따라 증가하였다. 그러나 간극수압비$(u/{p_c}')$는 압밀시간에 비례하게 감소하는 등 모래의 정적전단에서 나타나는 aging 효과를 관찰할 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1512-1519
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• 2013

Oil-impregnated paper is a major type of insulation used in oil-filled converter transformers for both traditional and new energy systems. This paper presents and analyzes the results of the experiment conducted on the electrical aging of oil-impregnated paper under AC-DC combined voltages using the pulsed electro-acoustic (PEA) technique. The formation and dynamics of space charge affected the performance of insulation material. The electrical aged oil-paper insulation was obtained through electrical aged experiments under the voltages. Based on the PEA technique, measurements were carried out when the oil-paper insulation system was subjected to different stressing and aging times. The space charge dynamics in the bulk of the oil-paper insulation system with different aging times were measured and analyzed. Characteristic parameters such as the total charge injection amount, the total charges of fast moving and slow moving, and the distortion factor of electric field were calculated and discussed. Results show that the longer electrical aging time, the more charges trapped in the bulk of aging sample. It leads to larger distortion factor of electric field in the bulk of aging samples and accelerate degradation of oil-paper insulation under AC-DC combined voltages.

• 한국축산식품학회지
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• 제43권3호
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• pp.412-427
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• 2023

The effects of wet-aging using a commercial refrigerator (CR, 4℃) and a pulsed electric field refrigerator (PEFR, 0℃ and -1℃) on the quality of sous vide pork loin were analyzed. The moisture and fat contents, pH, CIE L^*, CIE b^*, chroma, and shear force of the wet-aged samples were lower than those of the raw meat samples, whereas the water holding capacity (WHC) was higher. The PEFR group showed higher pH, CIE b^*, chroma, and WHC and lower weight loss than the CR samples. Electronic nose analysis indicated that positive flavor compounds were induced whereas negative flavor compounds were inhibited in the PEFR group. Wet-aging increased the sourness, saltiness, and umami of sous vide pork loin; the PEFR 0℃ samples showed the highest umami. Sensory evaluation indicated that wet-aging improved the color of sous vide pork loin. The PEFR 0℃ samples were rated higher than the raw meat and CR samples for all sensory traits. In conclusion, sous vide after wet-aging using a PEFR improved the quality of pork loin.

• 해양환경안전학회지
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• 제25권7호
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• pp.874-880
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• 2019

우리나라는 2000년 고령화 사회에 진입한 이후 2019년 현재 고령사회로 분류되고 있다. 이에 따라 고령선원의 수는 해를 거듭할수록 증가하는 추세이고, 고령선원의 해양사고 건수도 해마다 증가하고 있다. 도로 교통분야에서도 운전자의 고령화가 해운분야와 동일하게 나타나고 있다. 하지만, 도로 교통분야에서는 이러한 문제를 해결하려는 연구와 정책 등이 해운분야에 비해 활발하게 진행되었다. 이에 본 연구에서는 도로 교통분야에서 고령운전자에 의한 교통사고 발생원인을 줄이기 위한 노력 중 교육분야에 한정하여 살펴보고 이를 해기교육에 벤치마킹하였다. 국내·외 도로 교통분야에서는 인적요인 등의 발생원인을 줄이기 위한 방안의 하나로 고령운전자 교통안전교육을 시행하고 있다. 고령화에 따른 교육분야 문제 현황을 분석하고 도로 교통분야의 해결방안과 접목하였으며, 그에 따른 해기교육 개선방안은 다음과 같다. 첫째, 전문적인 면허취득교육을 시행하는 방안이다. 둘째, 고령선원의 면허갱신 시 직무 보수교육을 시행하는 방안이다. 마지막으로 고령선원 연령전환 교육을 시행하는 방안이다. 다만, 본 연구는 선원고령화에 따른 해기교육분야의 개선방안에 한정된 연구인 만큼 향후 다양한 분야에서의 연구가 필요할 것으로 판단된다.

• 한국전기전자재료학회논문지
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• 제20권8호
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• pp.691-696
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• 2007

In this study accelerated aging test equipment was developed to simulate domestic weather condition for accelerated aging test of polymer housed distribution surge arresters. Polymer arresters were aged for 3,000 hours by this test equipment and chemical and electrical characteristics analysis of surge arresters were conducted after aging test. In addition, performance assessment of outdoor installed arresters for 3 years was conducted to compare aging effect between accelerated aging test and natural aging. Through this experiment it is verified that the capability of the proposed aging test for simulating natural aging and the housing material and disconnector of domestic polymer arresters can be deteriorated by the long time field operation.

• 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.