• 대한치과의사협회지
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• 제54권6호
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• pp.468-474
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• 2016

Korean government enacted the 1st Basic Plan for Low Fertility and Population Ageing in 2005 due to the long-lasting ultra-low birth rate. Based on the Act, Korean government set up a step-by-step strategic goal and establish a basic plan, every five years, to achieve the sustainable development of society corresponding to low fertility and aging society. Over the past decade, the 1st Basic Plan for Low Fertility and Population Ageing (2006-2010) and the 2nd Basic Plan for Low Fertility and Population Ageing (2011-2015) was executed. This year, based on the achievements and limitations of the 1st and 2nd Basic Plan, the 3rd Basic Plan for Low Fertility and Population Ageing begins. In this manuscript, I discuss the background of the 3rd Basic Plan and its significance in oral health area.

• 한국축산식품학회지
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• 제35권3호
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• pp.406-412
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• 2015

The combined effects of electron-beam irradiation and ageing of beef were examined. The irradiated samples at dose of 0 or 2 kGy were kept and analyzed for the microbial growth, shear values, meat color, and nucleotide-related flavor compounds at different ageing temperatures (2, 10, or 25℃) for 8 d. The irradiation effect on inactivation of foodborne pathogens was also investigated. The population of Listeria monocytogenes and E. coli O157:H7 inoculated in beef samples decreased in proportion to the irradiation dose, showing D₁₀ values of 0.66 and 0.65 kGy respectively. The irradiated beef eye of round had lower number of total aerobic bacteria (TAB) than nonirradiated one during the storage, but the TAB increased with higher ageing temperature (p<0.05). Especially, TAB increased sharply in non-irradiated samples aged at 25℃ after 4 d (p<0.05). With increasing ageing temperature and ageing time, shear force values decreased (p<0.05). The color a* values of the irradiated beef were lower than those of the non-irradiated throughout the ageing period (p<0.05). As ageing time and temperature increased, the amounts of inosine monophosphate decreased and the hypoxanthine increased (p<0.05). Relatively high ageing temperature could be used at irradiated beef eye of round to shorten the ageing time.

• 대한조선학회논문집
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• 제55권3호
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• pp.205-214
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• 2018

This paper deals with the experimental study on the hygrothermal ageing effect to the strength of Carbon Fiber Reinforced Plastics (CFRP) materials for marine leisure boat manufactured by vacuum assisted resin infusion method. The experiments performed consist of tensile, flexural and shear tests according to American Society for Testing and Materials (ASTM) and Korean Industrial Standards (KS) test methods. Test coupons are varied from uni-directional(UD, $0^{\circ}$, $90^{\circ}$), Bi-Directional (BD), and Double-Bias (DB) carbon fiber fabrics in conjunction with epoxy resin. The results of tensile test show that tensile strength reduces significantly while not the same degree of reduction is observed for elasticity modulus with respect to the existence of hygrothermal ageing effect. This implies that the tensile strain induced from external load holds steady values but ultimate strength values change widely under hygrothermal ageing effect. In case of the flexural test, $0^{\circ}$ UD shows more strength reduction than $90^{\circ}$ UD while BD has reduced values in both flexural strength and elasticity modulus under hygrothermal ageing effect. It is learned that the bending strain induced from external load and ultimate strength values are reduced with respect to hygrothermal ageing effect. Shear test performed only on DB materials, and the results show marginal reduction in ultimate strength and moderate reduction in elasticity modulus. This means that the shear strain varies more than ultimate shear strength with respect to hygrothermal ageing effect. The experiment conducted in this paper clearly demonstrates the differences in material properties of the CFRP for the consideration of hygrothermal ageing effect. Findings obtained from this experimental study can serve as a fundamental input data for the realistic structural responses of marine leisure boat built in CFRP materials.

• 한국시스템다이내믹스연구
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• 제17권1호
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• pp.107-134
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• 2016

Accelerated ageing with low fertility is one of the most critical problems in Korea. Because of ageing via low fertility, Korea will face a serious demographic cliff. This research primarily focus on the analyzing the dynamics of the marginal ageing state and decreasing population especially in Eup and Myeon region. This study based on the system dynamics approaches for finding causal loop structure of marginal ageing and critical mass of population disappearing. The results of this study are summarized as follows. First, demographic marginalization trends have already begun in the Eups and Myons of Gun. Second, marginal aging speed in Eup/Myeon areas is causing an population disappearing in the near future. Third, critical mass of population disappearing will begin when the rate of marginal aging is exceed 82% after 2023.

• Nuclear Engineering and Technology
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• 제8권3호
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• pp.151-157
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• 1976

냉간가공한 질칼로이-4의 가공시효(strain ageing) 현상이 진공속에서 변형온도 및 1143ppm-3500ppm의 산소 함량의 변수로써 조사되었다. 가공시효 현상이 0-10 % 냉간가공한 질칼로이-4의 경우 200-45$0^{\circ}C$의 온도구간에서 조사되었으며, 이때 가공시효 현상은 냉간가공량이 증가할수록 감소하는 현상을 보였다. 이 냉간가공에 따른 가공시효의 감소는 냉간가공시 발생한 결함에 의해 산소 원자들이 trapping 되는 결과로 기인된 것으로 고려된다. 냉간가공된 질칼로이-4의 최대 가공시효 응력은 함유된 산소의 량의 평방근에 비례한다는 사실이 밝혀졌다.

• 한국노년학
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• 제37권1호
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• pp.55-82
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• 2017

본 논문의 목적은 한국 정부가 인구 고령화 문제에 대응하고자 저출산 고령사회위원회를 통해 제시한 고령친화산업 활성화 정책 분석을 통해 한국의 고령친화산업 발전을 위한 함의를 제공하는 것이다. 이를 위해 제1-3차 저출산 고령사회기본계획에 제시된 고령친화산업 활성화 정책 중에서 한국 노인의 대표 3대 고통 완화와 직접적으로 관련된 정책을 분석 자료로 하여 그것의 구체적 내용, 공통 핵심 논리와 그 타당성을 분석해 정책적 이론적 함의를 도출했다. 분석 결과, 제1차 기본계획은 경제적 빈곤 문제 완화, 제2차 기본계획은 신체적 건강 문제 완화, 제3차 기본계획은 신체적 건강 문제와 심리적 외로움 문제 완화와 관련된 정책을 제시하였고, 이들은 공통적으로 논리적 한계를 지닌 성공적 노화와 활동적 노화 개념에 기반 해 있었으며, 분야의 협소함, 내용의 부실함, 정책의 불연속성을 띠고 있었다. 이상의 분석 결과는 연속성을 담보한 고령친화산업 활성화 정책이 내실 있고 다양해져야 하며, 성공적 노화의 탈-맥락성의 한계 및 소비자본주의와의 선택적 친화성, 활동적 노화의 예방 중심성, 노인의 (비)심리적 자원의 사회성, 사회투자국가 관련 리에이블먼트의 한계로부터 정책적 함의뿐만 아니라, 노화의 모델화를 통한 이분법적 노화 인식의 한계를 넘어 노화에 대한 사회 구성적 시각이 필요하다는 이론적 함의도 제공해주고 있다. 끝으로, 본 논문의 한계와 함께 필요한 후속 연구를 제안했다.

• 열처리공학회지
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• 제5권4호
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• pp.233-239
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• 1992

A study of the precipitation process of Al-Li binary alloy at low ageing temperature has been carried by electrical resistivity measurement. Two types of G.P.zones were formed during ageing at low temperature. G.P. (1) zone and G.P. (2) zone have been formed primarily at ageing temperature below $60^{\circ}C$ and at ageing temperature range of $80^{\circ}C$ to $100^{\circ}C$, respectively. Therefore the precipitation process of Al-Li binary alloy was as follows; G.P.(1) zone ${\rightarrow}$ G.P.(2) zone ${\rightarrow}{\delta}^{\prime}{\rightarrow}{\delta}$ G.P. (1) zone might be affected by excess vacancies, but G.P. (2) zone might be affected by secondary defects. clusters and Li-vacancy pairs. The activation energy for formation of G.P. (2) zone is 0.87eV. It is lower than that of Al-Cu alloy.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.307-310
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• 2005

Ageing behavior of the Al-Mg-Si alloy was modeled for the use of optimization of Al forging product. Typical precipitates of Al-Mg-Si alloy are a wide variety of metastable phases (e.g. GP zones, $\beta',\beta'$). These rod shaped particles take a role to hinder the dislocation movement. The precipitation sequence in Al-Mg-Si alloys is quite complex and the strength of precipitate particles differs with the ageing condition. In the present study, the ageing behavior of Al-Mg-Si alloy was investigated by using an industrial grade Al 6061 alloy forged product, which was a perform for an Al impeller for turbo charger. The precipitate hardening models by Esmaeili's approach were used for the analysis of ageing behavior.

• 한국지진공학회논문집
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• 제23권6호
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• pp.311-319
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• 2019

The number of aged bridges is increasing so that bridges over 30 years old account for about 11% of all bridges. Consequently, the development of a seismic performance evaluation method that considers the effects of ageing is essential for a seismic retrofitting process for improvement of the seismic safety of existing old bridges. Assessment of the damage situation of bridges after the recent earthquakes in Korea has been limited to the bearings, anchor, and concrete mortar on piers. The purpose of this study is to evaluate the seismic responses of PSC box girder bridges by considering the ageing effect of rubber bearings (RBs) and lead-rubber bearings (LRBs). The modification factor proposed by AASHTO is used to take into account the ageing effect in the bearings. PSC box girder bridges with RBs and LRBs were 3D modeled and analyzed with the OpenSEES program. In order to evaluate the ageing effect of RBs and LRBs, 40 near fault and 40 far field records were used as the input earthquakes. When considering the effect of ageing, the displacement responses and shear forces of bridge bearings (RBs and LRBs) were found to increase mostly under the analytical conditions. It was shown that the effect of ageing is greater in the case of RBs than in the case of LRBs.

• International Journal of Advanced Culture Technology
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• 제5권2호
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• pp.19-25
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• 2017

The research is to identify social networks of problems that have an influence on the quality of ageing people's lives by using social network analysis, based on the premise that there are differences in networks of ageing problems in urban and rural areas. From analyzing network of ageing people's problems using NodeXL, vertices in the networks of both urban and rural areas are well-connected. For urban areas, financial poverty is the core problem related to the quality of life. It has direct connections with illness and health, family responsibility, housing, role loss in community, and employment, which have positive or negative interactions with the quality of older people's lives. For rural areas, on the other hand, role loss in community is the major problem. It has direct connections with the elderly abuse, financial poverty, leisure activity, divorce, isolation and loneliness from society, education, and suicide. As a result, the research shows that the problems of ageing people have strong linkages and interactive effects with a structure of network, and the networks are different depending on types of places for living.