• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.591-600
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• 1998

We have examined 24 human aortas aged $46{\sim}90$ years obtained from autopsies. Most exhibited gross lesions of some degree on the lumenal surface. Using hot alkaline treatment (0.1 N NaOH) at $70{\sim}75^{\circ}C$ for 5 hours, we extracted and quantitated elastin portions from the aortic wall in 3 different segments (UTA=upper thoracic aorta, LTA=lower thoracic aorta, AA=abdominal aorta). We have found UTA had $70.6%{\pm}1.39$ (SE), LTA $61.6%{\pm}1.94$ (SE), AA $49.2%{\pm}1.84$ (SE) elastin respectively based on wet weight. The differences between segments are statistically significant (p＜0.05, 0.025). However, there is no significant correlation between the age of the patients and the relative amounts of elastin in each segment. We have also observed the structure of elastin in the internal elastic lamina (IEL) and tunica media (TM) with SEM (scanning electron microscopy), and discovered that the IEL shows various forms of elastolysis- broken sheets, discontinuity, various sizes of lumps, vesicles, and possible newly formed elastin in the aortic lesions (Song and Roach submitted to YMJ). From these studies we conclude that elastin in the aortic wall remains well balanced quantitatively with age in spite of evidence suggesting vigorous degeneration and regeneration in the atherosclerotic lesions.

• Journal of the Korean housing association
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• v.21 no.1
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• pp.171-180
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• 2010

Amongst society's transitional presuppositions towards the future, population aging is the most critical issue in Korea. Immediate attention to devise a countermove is required. One of the major trends appeared in retirement communities of advanced countries is social integration which has been considered as a promising future direction of elderly housing development. This study aims to find out social integration characteristics and to categorize local engagement types of recent retirement communities through the characteristics of sharing common facilities and programs. Data were collected through mainly web site and literature reviews. Contentent analysis technique was used. Ten CCRC cases were selected through web search using the major key words such as 'intergenerational'. As a result, community engagement types were classified into six categories by the degree of sharing both physical and program resources between the retirement community and local area. This type can be utilized to develop alternative housing and retirement community for the older adults as a new model which activates the resident and vitalizes the retirement community through local engagement by physical and social resources.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1142-1145
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• 2004

ZnO surge arresters continuously endure the operating voltages during the operation course, and in the mean time, which need to withstand occasionally transient voltages of lightning and switching overvoltages. Under these voltages, the ZnO varistors inside arresters would have aging phenomena, one important result of aging phenomena is the increasing of resistive currents of varistors, which leads to the increasing of power losses of varistors. And the operating voltage is continuously applied on the ZnO varistors, there is a degradation phenomenon existing in ZnO varistors. When the degradation reaches a certain degree, then the arrester must stop operation. The degradation is related to the applied voltage ratio, the applied voltage ratio is high, the degradation is quickly. When the power loss is higher than the thermal dispersion ability of house of arrester, then the arrester will thermally breakdown. In this study the thermal stability characteristics of surge arresters for high power wil be discussed on the view point of watt losses and thermal breakdown.

• YAKHAK HOEJI
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• v.36 no.1
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• pp.56-65
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• 1992

The present study examined the effects of carbon monoxide (CO) intoxication and aging on learning and memory deficit in young($5{\sim}8$ weeks) and aged($52{\sim}66$ weeks) mice, using the step down and step through passive avoidance failure techniques. We also investigated the effects of ginseng saponins on memory deficit. Significant decrease in memory registration, retention and retrieval function in young mice and decrease in memory registration and retention function in aged mice were observed. Normal young mice were apt to perform to a great degree of passive avoidance response than normal aged mice, but there was no difference between both groups by CO exposure. Administration of ginseng saponins showed an improvement on passive avoidance failure induced by CO exposure.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.3 s.116
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• pp.61-65
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• 2006

The objective of this study was to find in what color Korean handmade paper(Hanji) is dyed when it is dyed with a pigment extracted from mugworts using different kinds of mordant, and how the paper is discolored and variety of strength under the condition of accelerated aging test. The results of this experiment are as follows. Among mugwort mordants, only ferrous sulfate mordant produced unique khaki color with a slightly lower degree of discoloration, so it is considered to be applicable in dyeing Korean paper. Bright yellow and light green colors were obtained using mugwort but their chroma was too low for actual use. With regard to water used, colors obtained using underground water had high chroma, but when distilled water was used paper was colored in useless light green. Mordant was found to lower the strength of Korean handmade paper, and the lowering of strength was even more serious under the condition of forced deterioration.

• Journal of the Korean housing association
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• v.22 no.4
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• pp.121-132
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• 2011

Hanok with a long tradition in our country, but a significant period of modernization in the process of being cut off did not have continuity. Many of Hanok aging, according to the rapid residential development and life-changing was the subject of a complaint. Conversely, the benefits of Hanok was given to the advantages that compare to a monotonous mass housing of apartments. Despite these changes and the potential of these social needs and demands Hanok quickly did not respond: First, for the life of contemporary and traditional Hanok with a form of gap is a matter of space and style. Economy and lifestyle $20,000 for the era of Hanok was to develop a model for spatial configurations. Second, Hanok in a low density, is evaluated to aging, because increasing the economic utilization of land and tailored to their needs as a Hanok housing requires the development of a model, but this did not present a layered model. The purpose of this study is a modern residential Hanok persistence of this set to have 1) the spatial characteristics of traditional and modern urban life Hanok living space that meets the requirements of the degree of each other, to find sustainable elements, and 2) these demands the modern residential area type, combined with a set of Hanok 3) Korea Hanok cultural characteristics which set is created to residential housing types is to develop a basic research.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.171-176
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• 2000

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. BI(Ball Indentation) test has a potential to replace conventional fracture tests like a uniaxial tensile test, fracture toughness test, hardness test and so on. In this paper, we would like to present the aging evaluation technique by the BI method. The four classes of the thermally aged 1Cr-1Mo-0.25V specimens were prepared using an artificially accelerated aging method. Tensile tests, fracture toughness tests, hardness tests and BI tests were performed. The results of the BI tests were in good agreement with fracture characteristics by a standard fracture test method. The IDE(Indentation Deformation Energy) of a BI technique as a new parameter for evaluating a degradation was suggested and the new IDE parameter clearly depicts the degradation degree.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.05a
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• pp.38-40
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• 1988

This paper was a study on dielectic characteristics of polypropylen film which were annealled in air and qunched in nitorgen after aging for 5[Hr]. Dielectric characteristics of specimen were measured in temperature of the range of 15-120[$^{\circ}C$], and in frequency of the range of $30-1{\times}10^6$[Hz.] As the result, for dielectric relaxation $\beta$-peak was observed in 20[$^{\circ}C$], and $\alpha$-peak was observed in 90[$^{\circ}C$]. Also, it was explained that $\alpha$-peak attributed due to armorphous region and $\beta$-peak attributed due to crystalline region and activation energy from dielectric loss spectra was obtained 34.5[kcal/mole] for $\alpha$-peak and 80.5[Kcal/mole] for $\beta$-peak, respectively.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.4 no.1
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• pp.21-30
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• 1974

A study was performed to investigate the degree of similarities and differences in components of craniofacial complex between Korean twins and normal children by lateral cephalometric analysis. Dimensions of S-N, S-Ba, N-Ba, Go-Me, Ar-Go and Ar-Me were against linear measurement and angles of N-S-Ba and gonial against measurement in twins and control groups. The lateral cephalograms of twin were composed of 88 twins aged from 7 to 12:44 males aged 10.65 and 44 females aged 9.55, while those of 50 normalities were composed of 25 males and 25 females aged 10.9 respectively. In order to analyze growth proportion and sexual differences, twins were divided into 3 groups according to two year age intervals and the author compared male with female in 3 groups. For the purpose of observing similarities and differences in twins and normalities by sex, total twins were compared with normalities. The obtained results were as follows: 1. There was no difference in craniofacial complex between plotted angular normalities. 2. In general, the measurements of male were larger than both twins and normalities, but there were no statistical sexual differences in both groups. 3. The growth proportion of mandible by aging was larger than that of face twins and those of female significances of in twins. 4. The growth pattern of gonial angle showed slightly reducing tendency in twins by aging. 5. There was little difference in the growth proportion of both male and female.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1909-1911
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• 2005

The electrical and chemical characteristics in transformer insulations are changed due to thermal stress. In the chemical property, as the Kraft paper ages, the cellulose polymer chains breakdown into shorter lengths with a corresponding decrease in both tensile strength and degree of polymerization(DP). Furthermore, cellulous chains 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 furan 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. In this paper the accelerated aging process of oil--paper samples have been investigated at a temperature up to $140^{\circ}C$ for 500 hours. The oil-paper insulation samples have been measured at intervals of 100 hours. For analysis we used high performance liquid chromatography(HPLC) in accordance with IEC 61198 method.