• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.479-482
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• 1999

Cured epoxy resins are extensively used for the electrical insulation in high-voltage equipments. The bisphenol A-based epoxy resins lured with azine show, especially, good thermal properties and mechanical resistances. For the technical and economic reasons, varing amount of inorganic fillers are added to endow the required special properties. In the large generators and motors of power plants, epoxy insulation is disclosed to the harsh conditions like the superheated steam and abrupt temperature variation. Hygrothermal aging at elevated temperatures tends to induce degradation in epoxy resins. To predict the effect of this degradation in DGEBA/MDA/SN/zeolite system, we proceeded the forced moisture absorption experiment using the autoclave. The thermal properties of the untreated and treated specimens were analyzed by DSC and TGA under the nitrogen flowing condition. The moisture absorption results showed a weight increase during hygrothermal aging at 1207. At the initial aging period, the system leaded to more or less postcuring but more prolonged environmental aging leaded the discoloration of specimen and lowering the T$_{g}$./.

• 한국가구학회지
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• 제22권4호
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• pp.287-298
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• 2011

In this study, I wanted to propose the design direction of the furniture and products in bathroom space so that the elderly's life is well supported to meet such aging societies that are getting older. Therefore, I have drawn the elders' needs by investigating their characteristics through literature research and used such needs as a frame of analysis to analyze the bathroom furniture and products made in Korea and foreign countries. The analysis results indicate:First, the elders need entertainment, health care, environment-friendly, convenience, good accessibility, chair-based bath and space separation; second, both Korean-made and foreign-made bathroom products are difficult to be controlled, invisible of font, hard to sustain the elders' bodies, inconvenient to be used and etc; and third, the design to solve such problems should be with intuitive user interface, easy control, better accessibility, the elders' moving patterns and living habits considered, health care, pro-environmental product. This study puts emphasis on the reflection of socio-cultural characteristics in designing bathroom furniture & items for aging society and requires more bathroom products with various designs in the foreseeable future.

• 대한토목학회논문집
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• 제41권5호
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• pp.591-599
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• 2021

현재 국내 철도시설 운영기관은 노후 시설물 판단을 위한 명확한 정의와 시설물 보수/개량 우선순위 산정 방법이 정립되지 않아 성능중심 유지관리계획 수립에 어려움을 겪고 있다. 따라서, 본 연구는 선행연구에서 노후 시설물을 어떻게 정의하였는지 고찰하고, 국내 노후 철도시설물 관리제도와 미국 연방대중교통청(FTA)의 교통시설물 자산관리체계 비교분석을 통해 벤치마킹 포인트를 도출하였다. 노후 시설물 판단은 경과연수와 성능수준을 같이 고려해야 하며, 경과연수와 성능등급 간 관계를 통계적으로 분석하여 보수/개량 우선순위를 산정해야 한다. 또한, FTA와 같은 데이터 기반 철도시설 관리를 위해서는 표준 철도시설물 분류체계를 기반으로 시설물 분류 하위 수준에서 내용연수, 성능평가 결과, 유지관리비용 데이터베이스를 구축하는 것이 필요하다. 향후 데이터가 충분히 축적되면 성능중심 노후 철도시설 관리를 위한 효율적 예산집행계획 수립에 기여할 것으로 기대된다.

• 한국노년학
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• 제37권1호
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• pp.251-270
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• 2017

본 연구의 목적은 베이비부머 대상 연구들에서 성공적 노화 모델을 어떻게 적용하고 있는지 연구경향을 분석하는 것이다. 구체적인 연구방법은 국내 논문의 성공적 노화 개념, 영향요인, 세대 특성 반영여부, 세대 내부 다양성에 대한 내용분석이다. 2000년부터 2016년 현재까지 국내 학술지에 게재된 124편의 논문 분석결과, 지금까지 연구들에서 성공적 노화의 개념은 주로 경제문제 차원이고, 연구모형에서 거시적 사회 환경 영향요인을 거의 고려하지 않으며, 세대 특성이나 세대 내부의 다양성을 구체적으로 반영하는 연구들도 적은 편이다. 앞으로 국내 베이비부머 대상 성공적 노화 개념에 대한 폭넓은 연구가 필요하고, 개념과 영향요인을 명료하게 구분하여야 할 것이다. 경제 가치 위주의 개인 단위 영향요인보다 노화 속 삶 자체 및 거시적 사회환경과 관련된 영향요인을 활용해야 한다. 베이비부머의 고유 특성을 이해하기 위하여 신노년문화적 가치 논의가 이루어져야 할 것이다. 마지막으로 베이비부머 세대 내 연령별, 성별에 따른 다양성에 관한 연구를 진행해야 할 것이다.

• 한국구조물진단유지관리공학회 논문집
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• 제25권6호
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• pp.95-102
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• 2021

유연한 고무재료를 사용하는 탄성받침은 최근 교량의 내진보강용으로 많이 적용되고 있다. 그러나 다양한 요인에 의하여 고무재료의 노화가 진행되고 이로 인해 탄성받침의 전단강성에 변화가 생기고 이는 교량의 내진성능에 영향을 미친다. 천연고무를 대상으로 노화촉진시간과 노출시간을 변수로 하여 노화촉진시험을 수행하여 전단특성의 변화를 분석하였다. 노화가 진행될수록(노화촉진온도 및 노출시간이 증가할수록) 최대전단응력과 전단변형율은 감소한다. 또한 동일한 전단변형률에서 전단강성이 크게 증가한다. 이는 고무재료가 경화됨을 의미하며 탄성받침의 내진성능이 저하되는 것을 암시한다.

• 대한본초학회지
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• 제38권4호
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• pp.45-52
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• 2023

Objectives : Fine dust caused by environmental pollution cause oxidative damage and skin aging. In this study, The possibility of using the Codium fragile extract (CFE) as an anti-aging product for skin improvement was evaluated by confirming the protective effect of skin cells from PM10 (particulate matter 10) through inhibition of ROS and MMPs. Methods : In this study, elastase and collagenase inhibitory activities were evaluated. Cell viability was evaluated by treating keratinocytes (HaCaT cell line) with CFE at various concentrations. The cytoprotective effect from PM10 in keratinocyteswas evaluated using the 3-[4,5-dimethylthiazol]-2-yl]-2,5-diphenyl-tetrazoliumbromide (MTT) assay. ROS (reactive oxygen species) was measured in keratinocytes damaged by PM10 using DCF-DA (2′,7′-dichlorofluorescin diacetate) fluorescence staining. As an anti-aging effect of CFE, MMP-1 (matrix metalloproteinase-1) and MMP-1 (matrix metalloproteinase-9) inhibitory activities were evaluated. Results : As a result, CFE decreased the activity of elastase and collagenase. As a result of evaluating the toxicity of CFE, it is non-toxic at a concentration of 10 to 80 ㎍/㎖. Although cell viability of HaCaT cells treated with PM10 decreased, cell viability increased by 38% when treated with CFE 80 ㎍/㎖. Also, ROS decreased by 8.4%, and MMP-1 and MMP-9 decreased at CFE 80 ㎍/㎖. Conclusions : CFE showed excellent cell protection effect, and it is considered that it can be used in anti-aging products for skin improvement by effectively inhibiting ROS and MMPs from keratinocyte damage caused by fine dust.

• Advances in Computational Design
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• 제2권2호
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• pp.147-168
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• 2017

Over the past couple decades, externally bonded fiber reinforced polymer (FRP) composites have emerged as a repair and strengthening material for many concrete infrastructure applications. This paper presents an analytical investigation of the use of carbon FRP (CFRP) for a specific problem that occurs in concrete bridge girders wherein the girder ends are damaged by excessive exposure to deicing salts and numerous freezing/thawing cycles. A 3D finite element (FE) model of a full scale prestressed concrete (PC) I-girder is used to investigate the effect of damage to the cover concrete and stirrups in the end region of the girder. Parametric studies are performed using externally bonded CFRP shear laminates to determine the most effective repair schemes for the damaged end region under a short shear span-to-depth ratio. Experimental results on shear pull off tests of CFRP laminates that have undergone accelerated aging are used to calibrate a bond stress-slip model for the interface between the FRP and concrete substrate and approximate the reduced bond stress-slip properties associated with exposure to the environment that causes this type of end region damage. The results of these analyses indicate that this particular application of this material can be effective in recovering the original strength of PC bridge girders with damaged end regions, even after environmental aging.

• 한국주거학회논문집
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• 제21권2호
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• pp.77-86
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• 2010

Korean population is now aging at an unprecedented rate. Fertility decline together with rapid improvements in life expectancy is the dominant demographic trend. As human life and housing environment are inseparably related to each other, the importance of conditions of housing environment for active aging among seniors has been received considerable attention as vital ones to expand the independency period of seniors. The purpose of this case study is to identify relationships between environmental affordance and perceived holistic health of the active elderly living in a retirement community located in Seoul. With spending time personally in the community to observe their lives, the researcher could be in close rapport with the residents. After the period of getting familiar with each other, in-depth individual interview and focus group interview were conducted and then, qualitative analysis was completed. As a result, general evidences showed that perceived seniors' health on the whole was improved physically, socially, and mentally by moving into the community providing appropriate environment affordance with the older adults. The study presents that retirement relocation into an improper environment may be a negative challenge, however, it may positively influence on the health and well-being of those who live there if the environment properly supports seniors‘ needs physically and socially

• KIEAE Journal
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• 제10권3호
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• pp.111-116
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• 2010

Ecological villages should be designed not only for simply reducing environmental impact such as energy saving and alternative energy use, resource conservation and circulation, harmony with surrounding environment and nature, but also for encouraging social contact and community activities with the residents, especially the aged people. The aim of this paper is to find the ecological and social design elements for the ecological village planning derived through case studies. The case studies are selected from the environmental Co-housings in Western America, surveyed in the years of 2008 and 2009. The results are as follows; 1. The ecological design elements, although there are some differences in size and type, were found to be basically applied in every ecological villages. 2. The community activities are actively conducted with the participation of the residents based on a variety of programs. The two main purposes of the community activities are strengthening the residents' familiarity with each other and the volunteer services to the local community where they belong.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.345-350
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• 2011

Antioxidant agent, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane were prepared and investigated the antioxidant activity on recycled rubber mat manufactured with waste tire powder. Mechanical properties of rubber mat are influenced by many factor such as compounding ingredients and state of cure, process of rubber, and fillers. Our study aim is to investigate influence of antioxidant activities on ozone cracking and the thermal aging time. In this work, the degradation of recycled rubber mat was studied and suggested mechanism to involve two-type of degradation, thermal aging and cracking both of which can be contained antioxidant or non-antioxidant agent.