• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.3
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• pp.343-349
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• 2017

The study was conducted to compare quality characteristics and antioxidant activities of aged black chestnut inner shells (ACI) and raw chestnut inner shells (RCI). RCI were aged for 15 days at high humidity and temperature. As storage time progressed, the pH level decreased while acidity increased. The sugar concentration ($^{\circ}Brix$) and reducing sugar concentration (%) increased during storage, whereas L (lightness) decreased. Compared with RCI, L value of ACI was darker than that of RCI after 9 days of storage. In the Hunter color system, L and a (redness) values of ACI were higher than those of RCI, whereas there was no visible difference in degree of aging. Although total phenol contents increased with degree of aging, phenol contents of ACI increased more than those of RCI after 9 days of aging. $IC_{50}$ values for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities decreased with degree of aging. Based on these results, it is suggested that aged black chestnut inner shells were appropriate in terms of both physicochemical and antioxidative activities.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.4
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• pp.1-10
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• 1998

The magnitudes of historical earthquake records related with house collapses are estimated considering the magnitude, epicentral distance, soil condition and aging of a house. Eighteen artificial time histories for magnitudes 6-8, epicentral distances 5 km-350 km and hard and soft soil condition were generated. Nonlinear dynamic analyses were performed for a traditional three-bay-straw-roof house. The aging effect of the house was modeled as such that the lateral loading capacity of wooden frames represented by hysteretic stiffness was decreased linearly with time. The house was idealized by one degree-of-freedom lumped mass model and the nonlinear characteristics of wooden frames were modeled by the Modified Double-Target mode. For far field earthquakes, minor damages were identified regardless of magnitude, soil condition and aging of the house. For intermediate field earthquake, earthquake magnitude greater than 6.5 caused severe damages in soil sites. For near field earthquake, severe damages occurred for magnitude greater than 6.5 regardless of soil condition and aging of the house. It is estimated that the magnitude of historical earthquakes is about 6.2. An empirical equation of magnitude-intensity relationship suitable to Korea is suggested.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.9
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• pp.1561-1565
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• 2007

According to thermal degradation on power transformers, it is known that electrical, mechanical and chemical characteristics for power transformer's oil-paper are changed. In the chemical property, especially, when the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. Also the paper breakdown is accompanied by an increase in the content of various furanic compounds within the dielectric liquid. It is known that furanic components in transformer oil come only from the decomposition of insulating paper rather than from the oil itself. Therefore the analysis of furanic degradation products provides a complementary technique to dissolved gas analysis for monitoring transformers when we evaluate the aging of insulating paper by the total concentration of carbon monoxide and carbon dioxide dissolved in oil only. Recently, the analysis of furanic compounds by high performance liquid chromatography(HPLC) using IEC 61198 method for estimating degradation of paper insulation in power transformers has been used more conveniently for assessment of oil-paper. It is know that the main products which is produced by aging are 2-furfuryl alcohol, 2-furaldehyde(furfural), 2-furoic acid, 2-acetylfuran, 5-methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde. For investigating the accelerated aging process of oil-paper samples we manufactured accelerating aging equipment and we estimated variation of insulations at $140^{\circ}C$ temp. during 500 hours. Typical transformer proportions of copper, silicon steel and iron have been added to oil-paper insulation during the aging process. The oil-paper insulation samples have been measured at intervals of 100 hours. Finally we have analyzed that 2-furoic acid and 2-acetylfuran products of furanic compounds were detected by HPLC, and their concentrations were increased with accelerated aging time.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.3
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• pp.284-291
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• 2002

An attempt was made to evaluate the degree of aging degradation in thermally aged 2.25Cr-1Mo steel by electrical resistivity measurement. Artificial aging was performed to simulate the microstructural degradation in 2.25Cr-1Mo steel arising from long time exposure at $540^{\circ}C$. Microstructural parameter (amount of solid solution element), mechanical property (ductile-brittle transition temperature) and electrical resistivity were measured to investigate the mutual relationship among these parameters. Depletion of solid solution element(Mo and Cr) in matrix was detected after aging. The ductile-brittle transition temperature(DBTT) increased rapidly in the initial stage of aging and then saturated afterward. On the other hand, the electrical resistivity decreased rapidly in the beginning and then saturated in the later stage of aging.

• The Korean Journal of Community Living Science
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• v.20 no.2
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• pp.275-289
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• 2009

The purpose of this study is to examine the middle aged's perception of aging and the degree of physical/financial/social preparation for later life and to explore the effect of the middle aged's perception of aging, who live in Gwangju & Jeonnam of Korea, on physical/financial/social preparation for later life. This research also explores gender differences in perception of aging, preparation for later life and related factors. For the purpose, the survey data was gathered from 424 middle aged (40's & 50's) citizens who live in Gwangju and Jeonnam, using structured questionnaire. The statistical methods used for data analysis are descriptive statistics, cross tables, t-test, correlations and regression with Spss/win 17.0 program. The major findings of this study are as follows: Most of the respondents perceive that the age of being aged is 65 or 70 years old. Respondents feel anxiety about health (84%), finance (57%) and roleless role (22%) of later life. Female group feel health anxiety more than male group. Many people perceive that social preparation for later life is better than financial preparation and physical preparation for later life. The result shows that female group perceives their physical preparation level more positively than male group generally. But, there were no differences in financial and social preparation between gender groups. Finally, the result shows the meaningful relationships between male group's perception of aging and financial preparation for later life. Monthly income is the most important variable predicting preparation for later life.

• Journal of Convergence for Information Technology
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• v.11 no.2
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• pp.16-24
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• 2021

This paper introduces a smart aging service that helps the elderly lead a happy old age by actively utilizing IoT and AI technologies for the elderly who are increasing rapidly as they enter the aging society. In particular, we propose a future-oriented, age-friendly well-being support system that breaks away from the existing welfare concept to solve the aging problem but leads to a paradigm shift toward building a vibrant aging society by protecting from emergency and satisfying emotions. By introducing IoT and AI, it judges the life situation and emotional state from the living information of the elderly can respond to emergencies and suggest meetings as a change of mood and give an emotional comfort. Since the proposed system uses artificial intelligence techniques to determine the degree of depression when inputting information such as pulse-rate, dangerous word usage, and external communication, I think it showed the feasibility of the new concept of wellbeing support system that is totally different from conventional wellbeing concept of health-care.

• Journal of the Korean Ceramic Society
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• v.32 no.3
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• pp.305-312
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• 1995

Thin films of Pb(Mg, Zn)1/3Nb2/3O3 were fabricated by spin coating the Pb-Mg-Zn-Nb-O complex alkoxide sols on(111) Pt-coated MgO (100) planes. It was observed that the content of H2O and the rheological characteristics of sol greatly influenced the orientation of perovskite grains after thin-film formation. A strong preferential orientation of (100)-type planes of the perovskite grains was obtained for the sol aged for 15 days with the molar ratio of H2O to total metal alkoxides=2. As small angle X-ray scattering experiment in the Porod region was performed to correlate the observed preferential orientation with the network structure of precursors at various stage of aging. It was shown that the degree of branching of the Pb-Mg-Zn-Nb-O precursor chain had a direct effect on the preferred oreintation, and weakly branched precursor systems led to highly oriented grains after thin-film formation.

• The Journal of Korean Society of Virology
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• v.28 no.2
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• pp.183-192
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• 1998

DNA methylation degree in the several murine brain and liver genes of different ages and after scrapie infection have been examined by using methylation-sensitive restriction endonuclease digestion. We found that the methylation of c-fos and c-myc in the brain and liver was increased during the late fetal to one month postnatal developmental periods. However, those of the SGP-2, $S100{\beta}$, APP950, PrP, and APLP1 genes were decreased at the same periods. The comparison of the DNA methylation patterns between scrapie infected brains and controls demonstrated there is no significant difference in methylation degree of scrapie-infected brains. These observations indicate that DNA methylation might be importantly related to the aging process. The scrapie-infected murine brain was not significantly developed more senescent than the same age-controls did.

• Electrical & Electronic Materials
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• v.1 no.1
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• pp.54-61
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• 1988

This paper was a study on dielectric phenomena of the specimen, Polypropylene films which were annealled in air and quenched in liquid nitrogen after aging for 5[hr] in water of 100[.deg.C]. The specimen was measured in temperature range of 15-120[.deg.C] and in frequency range of 30-1x 10$^{6}$ [HZ]. As the results of the study, it was confirmed that the tacticity of specimen was isotactic structure, and the degree of cryatallinity of the specimens calculated by means of Natta's method from XRD (X-ray Diffraction) spectrum was 55[%]. And for dielectric relaxation, .betha. peak-the tan .delta. (spectrum around 20[.deg.C])-attributed due to amorphous regions, and .alpha. peak - the tan .delta. spectrum around 90[.deg.C]-due to crystalline regions. It was identified that the degree of crystallinity of the specimen quenched in the liquid nitrogen was increased to 55-65[%], and that of the specimen annealled in the air was decreased to 55-50[%]. And activation energy from dielectric loss spectra was obtained 34.5[kcal/mole] for .alpha. peak and 80.5[kcal/mole] for .betha. peak, respectively.

• Applied Microscopy
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• v.28 no.1
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• pp.21-38
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• 1998

The present study was performed to determine the effect of cold stress on myocardium of aging rat. Control groups, which aged 6, 12 and 24 months, were compared with age-matched experimental groups that were exposed to moderate cold stress for a hours daily in a week at laboratory cold room $(4{\pm}1^{\circ}C)$. The histological, histochemical and ultrastructural changes of myocardium were observed. The results were summarized as follow: 1. Age-dependent histological change of control groups was observed the formation of contraction band in 24months aged group. The experimental groups submitted to cold stress showed a similar change pattern as seen in control groups. However, the degree of change in the experimental groups was significantly larger than that of control groups. In the 34 months aged group the formation of hypercontraction band was observed. 2. Regarding age-dependent histochemical changes of control groups, we observed the increase activities of PAS and Masson's trichrome. In experimental groups the activities of PAS and Masson's trichrome were also increased with age. Compare with control group, the activities of PAS was increased but the activities of Masson's trichrome was decreased. 3. Age-dependent ultrastructural changes on vacuolization, lysosome were observed. In control groups the structural changes occur at 12 months. The accumulation of lipofuscin, contraction band, hypercontraction band and a component of connective tissue were observed in 24 months. However, the degree of change in the experimental groups was significantly larger than that of control groups. In contract, the myelin body in intercalated discs was observed in 24 months of experimental groups.