• Journal of Korean Society of Rural Planning
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• v.20 no.4
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• pp.183-192
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• 2014

The purpose of this study is to examine the effect of regional ageing rate to industrial structures of rural areas in Korea. This paper shows that there are cause-effect relations between the industrial specialization and ageing rate in 'Agriculture', 'Finance & Insurance', and 'Real Estate & Leasing' sectors. The ageing levels are classified into ageing society, aged society, and super-aged society according to UN standard that cause different impacts on industrial specialization of regions. This paper finds that the industrial specialization is determined by the ageing levels. If there is an increase in ageing rate by 1% in ageing society, the industrial specialization of the three industries could be strengthened by 0.14%. But, ageing rates have negative impacts on the industrial specialization in aged society and super-aged society by 0.76% and by 1.20%, respectively, as increasing ageing rate by 1%. As the ageing rate progresses, 'Agriculture', 'Finance & Insurance' and 'Real Estate & Leasing'sectors have positive impacts on the industrial specialization in the ageing society. But 'Finance & Insurance' and 'Real Estate & Leasing' sectors have changed into negative impacts on the industrial specialization in the aged society. In the aged society, the employment of elderly persons of 'Agriculture' and 'Finance & Insurance' sectors increase by 1% makes positive impact on the industrial specialization by 1.54%, by 0.45%, respectively. The result of this paper can be applied to a significant guideline at establishing regional employment planning such as elderly customized employment, vocational training for rural areas, where above 14% of ageing rate.

• Nuclear Engineering and Technology
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• v.9 no.3
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• pp.117-123
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• 1977

The strain ageing behaviour of quenched Zircaloy--4 has been studied as a function of ageing time and temperature in the temperature range 523 to 588 K for a short-ageing time of 1 to 52 seconds. At the test conditions, the strain ageing stress increased with ageing time and temperature at a strain rate of 5.55$\times$10$^{-4}$ sec$^{-1}$ . Applying stress on the Quenched Zircaloy-4, the strain ageing effect indicated following two stages: an initial stage having an activation energy of 0.39 ev considered to be due to Snoek type ordering of intersitial oxygen atoms in the stress field of a dislocation and a second stage having an activation energy of 0.60 ev, due to mainly long-range diffusion of oxygen atoms.

• Management & Information Systems Review
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• v.18
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• pp.1-19
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• 2006

Ageing induces huge dramatic change of society and economy rather than simple change of population structure. Ageing causes the decrease of working age population and production capable population, thus this brings growth slowness and long-term stagnation. In addition, progress in ageing decreases saving rate, consequently low saving rate brings about the decrease of country-wide investment resources. This ageing problem which is progressive rapidly needs core competence and implementation of human resource professionals to overcome this kind of environment change. First of all, it needs turnover in thinking way toward talents. Secondly, we need innovation one team to pursue innovation and creativity. Thirdly, it should be considered in a new way with the number of workers and efficiency of personnel expenses. Fourthly, employees should make effort for self-advancement. Under the environment with newly change human resource personnels' function and role should be emphasized to maintain sustainable growth and overcome the change of management environment. Therefore, human resources should be emphasized to become competitive personnel and organization with leading the change master and creating the value of the organization.

• Nuclear Engineering and Technology
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• v.5 no.1
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• pp.55-64
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• 1973

The effect of compression in the strain ageing of Ferrovac E iron has been examined with compressive testing following the prestrain in compression. Both prestraining and testing were preformed at room temperature with the strain rate of 1.9$\times$10$^{-4}$ se $c^{-1}$ and that of 0.95$\times$10$^{-4}$ se $c^{-1}$ , respectively. Ageing was carried out at several temperatures below 8$0^{\circ}C$ using thermostatically controlled oil baths with a temperature control within$\pm$1$^{\circ}C$. It was found that the rate of strain ageing obeyed the $t^{2}$3/ law up to about five hours ageing at 6$0^{\circ}C$. The rate was slower than theses reported in case of the tensile prestrained iron. Activation energy for strain ageing has been estimated as 21.5 Kcal/mole at tile first stage of the aging process. At the second stage of ageing where the $t^{2}$3/ law is still valid, however, the activation energy was somewhat decreased. The activation energy at the first stage of ageing was about 10% larger than published results on the tensile-prestraining. This difference between the activation energies is explained in terms of the residual stress field in lattice.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.4
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• pp.161-172
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• 2020

The tensile property of A5082 and A6060 aluminium wrought alloys was investigated, in terms of the strain rate sensitivity on alloy conditions by heat treatment and bake hardenability on pre-strain prior to strain ageing. The tensile test was carried out in a range of strain rate of 4.17 × 10^-5 s^-1 ~ 4.17 × 10^-5 s^-1 in room temperature and the nominal range of pre-strain was 3.0 ~ 10.5%. The tensile deformation of A5082 alloys is characterized as typical case of dynamic strain ageing with negative strain rate sensitivity for all conditions, and the tensile strength indicates a similar level regardless of alloy conditions, except only in full annealed condition. The stress-relief annealing on A6060 alloys can induce practical decrease in strength level of over approximately 100 MPa without any ductility loss, compared to as-rolled condition, while a full annealed and aged condition leads remarkable strengthening effect with the decrease of tensile elongation. Additionally, the bake hardenability of A5082 alloy by strain ageing indicates a negative dependence upon the increase of pre-strain, while A6060 alloy exhibits a positive sign even in low level relatively compared with conventional SPCC.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.668-675
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• 2013

We investigate the effect of the ageing time and etching time on the etching rate of SiGe mixed etching solution, namely 1 vp HF (6%), 2 vp $H_2O_2$ (30%) and 3 vp $CH_3COOH$ (99.8%). For this etching solution, we found that the etch rate of SiGe layer is saturated after the ageing time of 72 hours, and the selectivity of $Si_{0.8}Ge_{0.2}$ layer and Si layer is 20:1 at ageing time of 72 hours. The collapse was appeared at the etching time of 9min with etching solution of after saturation ageing time.

• Transactions on Electrical and Electronic Materials
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• v.7 no.5
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• pp.235-239
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• 2006

Charge dynamics in polymeric materials after aged under ac electric field using the pulsed electroacoustic (PEA) technique is reported. The emphasis is placed on charge decay. The charge dynamics of the ac aged additive free low density polyethylene (LDPE) samples under dc bias differ from the sample without ac ageing, indicating changes brought in by ac ageing. It is believed that a slow decay rate of charge in the ac aged sample is related to the formation of deep traps in the material. However, chemical analysis by infrared spectroscope (FTIR) and Raman microscope reveals no significant chemical changes taken place in the bulk of the material after ac ageing. Further experiments on irradiated LDPE have revealed a similar behaviour, i.e. the charge decay is slower in irradiated samples than that of fresh sample. The findings presented clearly indicate that space charge measurement can be used as a diagnostic tool to monitor ageing in polymeric materials.

• Korean System Dynamics Review
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• v.17 no.1
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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.

• The Journal of the Korean dental association
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• v.54 no.6
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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.

• Proceedings of the KWS Conference
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• 1994.05a
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• pp.44-47
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• 1994

The ageing behavior of Cu-bearing HSLA steels was studied by using Differential scanning calorimetry(DSC), Transmission electron microscopy and hardness tester. Two heat evolution peaks were observed during DSC scans over the temperature range of 25～590$^{\circ}C$ at a heating rate of 5$^{\circ}C$/min. The peaks appeared in low (241∼319$^{\circ}C$ : HSLA-A, 224∼310$^{\circ}C$ : HSLA-B) and high temperature (514∼590$^{\circ}C$ : HSLA-A, 451∼558$^{\circ}C$ : HSLA-B) are attributed to the formation of coherent Cu-clusters and noncoherent $\varepsilon$-Cu phase, respectively. It was confirmed that as ageing proceeds, the coherent bcc Cu-clusters transform to noncoherent fcc $\varepsilon$-Cu phase. In the case of the ageing to peak hardness at 300$^{\circ}C$ and 400$^{\circ}C$, the coherent Cu-clusters contributed to the hardening. As ageing time and temperature increase over peak hardness, noncoherent $\varepsilon$-Cu are formed and hardness decreases.