• 열처리공학회지
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• 제8권4호
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• pp.245-254
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• 1995

The purpose of this study was to examine the effects of low melting point phase(LMPP) on mechanical properties in the Al-Cu-Li-X(In, Be) alloys. This study was performed by the differential scanning calorimetry(DSC), the transmission electron microscope(TEM), hardness test, tensile test and notch tensile test. The shape of LMPP in the specimens homogenized at $570^{\circ}C$ was film type due to remelting at grain boundary during homogenization. Low melting point phases had no effects on mechanical properties in the aging treated materials, because the density of LMPPs was low. Mechanical properties of the aging treated materials were affected by the density of matrix precipitation phases and grain sizes. For the In or In, Be added Al-Cu-Li alloys, the optimum solution treatment temperature was $550^{\circ}C$. The strength of Al-Cu-Li-In-Be $T_6$ treated alloy was higher than that of 2090-$T_8$ alloy.

• 한국주거학회논문집
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• 제25권1호
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• pp.33-40
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• 2014

As China has the largest number of elderly people in the world, the issue of the aged people has been a serious matter of concern in Chinese government and society and many studies have been done so far. However, the studies about the dwellings of the aged people that support their basic life are still insufficient. For this reason this study intends to identify the differences in elderly people's preferences according to their situations in aged life. This study surveyed 152 elderly residents aged 50 and over including early aged people in Beijing China about their residential preferences (types of residence, location of residence, size of residence, types of ownership) according to the four types of their situations in aged life, healthy couple, sick couple, healthy single and sick single. The survey conducted from 2013 April 10th to 15th. The results were as follows: Firstly, as the elderly situation became worse, preference for the independent residence decreased very rapidly while the preference for the elderly welfare facilities dramatically increased from the 0 point of the healthy couple and the preference for the elderly welfare facilities marked the highest point in case of the worst situation of sick single. Secondly, among the four different situations preferences for the urban residence were the highest and as the aged people's situation becomes worse, their preferences for urban life increased. Thirdly, healthy couple preferred a large size residence but as their elderly situation becomes worse, their preferences for the large size decreased and their preferences for small size increased dramatically, and in case of elderly singles, preferences for small size residence exceeded their preferences for large size residence. Fourthly, as elderly situation became worse preference for owning residence decreased and preference for rental residence increased and in case of the worst situation of sick single, preference for rental residence was higher than their preferences for their own residence. With this view of point, the residential preference of elderly people changes along with their aging situations. Thus, the government should consider the variable aging market, and develop a variety of aging residence which, can satisfy the different groups of elderly.

• Journal of Photoscience
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• 제9권2호
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• pp.150-153
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• 2002

Solar UV light is a well-known carcinogen. UVA radiation is probably carcinogenic to humans. In addition, recent investigations point to the importance of UVA irradiation in the photoaging. We investigated the mechanism of sequence- specific DNA damage using $\^$32/P-Iabeled DNA fragments in relation to carcinogenesis and aging. Furthermore, we investigated whether UVA accelerates the telomere shortening in human WI-38 fibroblasts. The exposure of double- stranded DNA fragments to 365 nm light in the presence of endogenous sensitizers produced sequence-specific cleavage at the 5' site of 5'-GG-3' and 5'-GGG-3' sequences. In addition, HPLC analysis revealed that sensitizers plus 365 nm light increased the 8-oxodG content of double-stranded DNA. We discuss the mechanisms of guanine-specific DNA damagecaused by excited photosensitizers in relation to carcinogenesis and aging.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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• pp.132-136
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• 2002

In this paper, aging characteristics of outdoor silicone rubber insulator resulting from the acid rain have been investigated with regards to nitrate ion $({NO_{3}}^{-1})$. For this purpose, silicone rubber was aged by immersing into the nitric solutions with different level pH during 1500 hours and various tests (tracking, $tan{\delta}$, breakdown voltage, SEM, EDS, contact angle) were performed. It was observed that the degradation was increased to pH 2.5 slightly and at pH 1.5 highly. And thus, it could be expected that there is certain critical point between pH 1.5 and 2.5, which leads to throught degradation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
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• pp.28-33
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• 2001

In this paper, aging characteristics of outdoor silicone rubber insulator resulting from the acid rain have been investigated with regards to nitrate ion ($NO^{-1}_{3}$ ). For this purpose, silicone rubber was aged by immersing into the nitric solutions with different level pH during 1500 hours and various tests (tracking, tan $\delta$, breakdown voltage, SEM, EDS, contact angle) were performed. It was observed that the degradation was increased to pH 2.5 slightly and at pH 1.5 highly. And thus, it could be expected that there is certain critical point between pH 1.5 and 2.5, which leads to throught degradation.

• 건설안전기술
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• 통권55호
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• pp.10-17
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• 2012

Aging society may approached to our society during snatch very, and enter in super aging society for more span. Investment that we which live 21th century are many in people's quality of life elevation meantime did not consist, but stand in visual point that must improve many portions forward. For front, repletions for many equipments that consider aged on our society must consist, and much researches may have to be gone for this. According to traffic accident result, percentage of older pedestrian deaths was 46.5% as much in Korea. In particular, the crossing accidents by 59% or more of the older pedestrian traffic safety measures that target is an urgent situation. Therefore, in this study was to identify the domestic status and problem on no-sidewalk region for older pedestrians. In addition, side walk the installation and maintenance plan presented to prepare for aging society.

• Structural Engineering and Mechanics
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• 제17권1호
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• pp.29-50
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• 2004

A total life model was developed to assess the service life of aging aircraft. The primary focus of this paper is the development of crack growth life projection using the response surface method. Crack growth life projection is a necessary component of the total life model. The study showed that the number of load cycles N needed for a crack to propagate to a specified size can be linearly related to the geometric parameter, material, and stress level of the component considered when all the variables are transformed to logarithmic values. By the Central Limit theorem, the ln N was approximated by Gaussian distribution. This Gaussian model compared well with the histograms of the number of load cycles generated from simulated crack growth curves. The outcome of this study will aid engineers in designing their crack growth experiments to develop the stochastic crack growth models for service life assessments.

• 전기학회논문지
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• 제60권2호
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• pp.338-343
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• 2011

In this paper, the FT-IR, conductivity and flow electrification phenomena of Vegetable oils were discussed. Vegetable oil has high flash point and eco-friendly properties compared to conventional mineral oil. Accelerated aging transformer oil samples produced in the oven at 140[$^{\circ}C$] for 500 hours, 1000 hours, 1500 hours, 2000 hours. Serial device to measure the flow electrification phenomena was designed and fabricated. Pico ammeter and the Labview data measurements were utilized. The effects of Temperature and antistatic agent on fluid flow electrification were investigated. Both Mineral and vegetable oil showed similar trends for temperature change. The polarity reversal occurred in mineral oil with antistatic agent above 10 ~ 30[ppm] and in vegetable oil with antistatic agent above 5[ppm].

• 한국수소및신에너지학회논문집
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• 제30권2호
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• pp.103-110
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• 2019

Cu-Zn-Al catalysts were prepared via co-precipitation method for low-temperature water-gas shift (LT-WGS) reaction under practical reaction condition. Aging time was systematically changed to find optimum point for LT-WGS under practical condition. The Cu-Zn-Al catalyst aged for 72 hours showed the highest CO conversion within low-temperature range as well as very stable catalytic activity for 200 hours despite the practical reaction condition.

• 디자인학연구
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• 제16권4호
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• pp.91-100
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• 2003

우리나라는 인구 고령화가 매우 빠르게 진행된다는 점에서 "고령화"는 우리의 현실이 되었고 고령화의 진전은 사회 전반에 걸쳐 광범위한 변화를 초래하였다. 그러나 이미 고령 사회에 진입한 선진국들은 고령화에 대한 대처가 활발히 진행되고 있으나 우리나라의 경우는 그렇지 않은 실정이다. 따라서 고령화에 대한 대비책 연구가 요구되며, 특히 고령 사회를 눈앞에 둔 시점에서 노인이 일상생활에서 겪는 불편과 곤란 등의 장애 해소에 종합적 대책이 신속하게 요구된다. 본 연구는 고령 사회를 대비한 디자인 기초 방향에 대한 내용을 문헌 연구하였다. 고령화에 대응하는 디자인 방향 모색은 시각 전환이 요구되며 이를 해결하기 위한 하나의 디자인 방법론이 유니버설 디자인이다. 고령화 대비를 위해 유니버설 디자인 구현은 종합적이고도 다각적 접근과 디자인 전략이 함께 구축되어야 한다. 다 함께 어울려 살 수 있는 사회를 만들기 위해 모두가 유니버설 디자인 마인드를 가진 건강한 고령사회를 기대 해본다.