• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.156-163
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• 2022

Loss of leg muscle and muscle weakness, which are caused by aging, affect muscle function and sense of balance. As a way of preventing seniors from falling, we developed the idea of wearing functional supporters based on graduated compression technique and in the form of a taping supporter. Their impact on power, sense of balance, overcoming fatigue, and subjective wearing sensation was investigated. The following results were obtained. After wearing functional compression supporters, body temperature increased from 24.5 ± 0.5℃ to 26.3 ± 0.6℃. Calf size, which assesses the level of edema, decreased from 26.1 ± 1.8cm to 25.7 ± 1.8cm. The result of dynamic balance test, which helps estimate the fall prevention effect, increased from 6.4 ± 0.9sec to 7.1 ± 0.6sec. Lactate level, which indicates the level of fatigue, decreased from 8.1 ± 0.6mmol/L to 7.3 ± 0.8mmol/L. Standing long jump record, which assesses power, increased from 110.1 ± 3.1cm to 112.0 ± 2.8cm. Standing on one leg with eyes closed, which assesses sense of balance, increased from 4.2 ± 1.1sec to 6.5 ± 0.8sec. Ankle angle, which assesses joint stability, increased from 75.3 ± 4.0° to 80.1 ± 1.7°. In metabolism and physical performance testing, which assesses keep, the score increased from 26.3 ± 1.7 to 28.8 ± 1.2. Muscle supporting score, which assesses joint stability, increased from 7.3 ± 0.6 to 7.8 ± 0.4. In the category of body type, which assesses wearing sensation and body shaping function, the score increased from 5.7 ± 1.4 to 6.4 ± 1.2

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.150-171
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• 2013

The most important part of conservation treatment of murals is to preserve them against the risk of a damage by injecting fixative into them when the painting loses its cohesion or powderization of pigments occurred due to occurrence of cracks inside the painting layer. However, studies on the stability of fixative used for painting layers of murals are still insufficient. This study manufactured a mural as a specimen and colored it with four kinds of pigments including oyster shell white, cinnabar, malachite and red clay and applied four kinds of fixative, including, Paraloid $B-72^{(R)}$, Caparol-$binder^{(R)}$, glue and Hydoxypropyl $cellulose^{(R)}$. artificially generated environmental changes in temperature, humidity and ultraviolet rays which may occur after the completion of conservation treatment. Then the changes in physical properties were observed in multifaceted ways such as color stability, contact angle, brilliance, adhesive strength and surface. As a result, this study found that ultraviolet rays and hot?humid environment have a large impact on color stability causing changes in brightness and chroma of all painting layers where the fixative were applied, except for oyster shell white and are considered the main factors of decomposition by accelerating the aging process of fixatives applied. In comparison to the synthetic resins that were also tested in this study, the traditional glue showed satisfactory results in terms of color stability and influence preservation and the hydrophile property. As it showed exceptionally outstanding adhesive strength in all painting layers in the aspect of adhesive strength, it is considered to be highly stabile for the fixation treatment of painting layers of mural.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.39-47
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• 1997

Retinol as well as RA is well known to have many beneficial effects on aged skin. But the skin irritation potential and unstable condition of the products containing them have been some problems in their cosmetic uses. So, retinol containing gel product was developed for less skin irritancy and more stability in cosmetic products. To examine the clinical effects of retinlo containing product, we used cilnicla non-invasive assessment techniques on 40 volunteers for 6 months maintaining double-blind test conditions. According to our results, the use of retinol containing product improved skin color and hydration level slightly. But there was no statistical differences. There was no erythema reaction compared to the use of RA. Especially, the skin elasticity increased above 20% and skin wrinkles of crows' feet region decreased more than 10%. Besides the instrumental analysis, a large majority of volnteers felt that their skin were improved in the case of wrunkles, elasticity, hydration and color.

• Journal of the Korean Ceramic Society
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• v.34 no.9
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• pp.986-992
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• 1997

Cordierite ceramic was prepared by sol-gel method. It was analyzed by Infrared spectroscopy and X-ray diffraction patterns that the ceramic was chemically mixed in molecular level and transformed to $\alpha$-cordierite at 125$0^{\circ}C$. Water vapour treatments for aging and drying process were conducted to get porous cordierite with thermally stable pore structure. It resulted in 220-410 $m^2$/g BET surface area and mesoporous structure with mean pore diameter, 40$\AA$. Compared to naturally dried ceramic, the ceramic showed superior thermal stability of surface area up to $700^{\circ}C$. Surfaces of porous cordierite ceramics were observed by SEM.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.134-138
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• 2000

The physical, electrical and piezoresitive characteristics of CrN(chromiun nitride) thin-films on silicon substrates have been investigated for use as strain gauges. The thin-film depositions have been carried out by DC reactive magnetron sputtering in an argon-nitrogen atmosphere(Ar-(5~25 %)$N_2$). The deposited CrN thin-films with thickness of $3500{\AA}$nd annealing conditions($300^{\circ}C$, 48 hr) in Ar-10 % $N_2$ deposition atmosphere have been selected as the ideal piezoresistive material for the strain gauges. Under optimum conditions, the CrN thin-films for the strain gauges is obtained a high electrical resistivity, $\rho=1147.65\;{\mu}{\Omega}cm$, a low temperature coefficient of resistance, TCR=-186 ppm/$^{\circ}C$ and a high temporal stability with a good longitudinal gauge factor, GF=11.17.

• Journal of the Korean Ceramic Society
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• v.29 no.9
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• pp.675-680
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• 1992

The purpose of this investigation was to study the stability of perovskite structure, the variation of electrical properties and a microstructure with varing amount of PbTiO3 additive in PZN-PT-BT system. The results are as follows: 1. The pyrochlore phase was reduced as the amount of PbTiO3 additive was increased and completely eliminated at 0.15PT in PZN-PT-BT system. 2. The aging rate was increased in proportion to tetragonality because the internal stress was increased in proportion to tetragonality. 3. On increasing the amount of PbTiO3 additive, the Curie temperature was increased in proportion to tetragonality. 4. As the amount of PT in the composition increase, the variation of dielectric constant was sharpened and the diffuseness of the transition decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.135-141
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• 2000

The physical, electrical and piezoresitive characteristics of CrN(chromiun nitride) thin-films on silicon substrates have been investigated for use as strain gauges. The thin-film depositions have been carried out by OC reactive magnetron sputtering in an argon-nitrogen atmosphere(Ar-(5~25 %)$N_2$). The deposited CrN thin-films with thickness of $3500{\AA}$ and annealing conditions($300^{\circ}C$, 48 hr) in Ar-10 % $N_2$ deposition atmosphere have been selected as the ideal piezoresistive material for the strain gauges. Under optimum conditions, the CrN thin-films for the strain gauges is obtained a high electrical resistivity, $\rho=1147.65\;{\mu}{\Omega}cm$, a low temperature coefficient of resistance, TCR=-186 ppm/$^{\circ}C$ and a high temporal stability with a good longitudinal gauge factor, GF=11.17.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.585-592
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• 2008

The aging society comes, the number of the old people expended. Technical aids allow elderly and handicapped people to live independently in their private homes as long as they wish. As a contribution to these required technological solutions, a demonstrator platform for a walking assistance robot. robot which has the capability to perform fetch and carry and various other supporting tasks. In this study, we addresses the development of a walking assistance robot system. We execute static analysis, vibration analysis and flexible dynamics to reserve stability at the design. Each motion of the robot uses a linear actuator and gears. Motion can be distinguished into 3 parts depending on the up & down, rotation, and cushion trans. In each motion, we compare the displacement of the case to be rigid with the case to be flexible. As a result, manufactured and feasibility of the walking assistance robot is validated through preliminary experiments.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1578-1583
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• 2007

The suspension system of railway rolling-stock is composed of the primary and secondary suspension elements. Recently, a conical rubber spring is widely used as the primary suspension element due to the merits of the three directional stiffness characteristics. So, understanding the properties and characteristics of the conical rubber spring is very important from the viewpoint of vehicle stability and efficient maintenance. Thus, this study is started to acquire the basic data for maintaining spring elements efficiently. For this, we tested the conical rubber spring samples including a new and old specimen with aging. As a test result, we have obtained the property characteristics of the aged spring comparing with the new product and we describe the results.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.4
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• pp.193-198
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• 2011

Effect of CaO addition on age hardening response has been studied by using optical microscopy, scanning electron microscopy and differential thermal analysis in AZ91 and CaO-containing ECO-AZ91 alloys. After solution treatment, the ${\beta}$($Mg_{17}Al_{12}$) phase formed during solidification mostly disappeared in the microstructure in the AZ91 alloy, whereas numerous ${\beta}$ precipitates containing Ca were still observed in the ECO-AZ91 alloy due to its enhanced thermal stability. The ECO-AZ91 alloy showed the delayed peak aging time and higher peak hardness compared with those of the AZ91 alloy. The activation energies for ${\beta}$ precipitation calculated by means of Kissinger method increased from 71.4 to 85.6 kJ/mole by the addition of CaO, which implies that CaO plays a role in reducing ${\beta}$ precipitation rate in the AZ91 alloy.