• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.25 no.3
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• pp.150-159
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• 2012

Objective : The purpose of this study was to evaluate the effect of korean herbal cosmetics for facial skin elasticity. Methods : We recruited patients and divided them to cosmetics group and control group randomly. We provided korean herbal cosmetics to cosmetics group and subjects in cosmetics group applied the provided cosmetics for 4 weeks. Control group waited and applied cosmetics that had previously used for 4 weeks. We assessed all subjects in 0 week, 2 weeks and 4 weeks. Primary assessment instrument was moire topography photo scale. Second assessment instrument was skin moisture, oiliness and elasticity which assessed with skintouch system v1.0, detox/regeneration questionnaire score and self-evaluating facial wrinkle/looseness score. Result : Moire topography photo scale improved in cosmetics group than control group significantly. Skin moisture and elasticity assessed with skintouch system improved in cosmetics group than control group significantly while skin oiliness assessed with skintouch system have not improved significantly. Detox/regeneration questionnaire score and self-evaluating facial wrinkle/looseness score improved in cosmetics group than control group significantly. Conclusion : Korean herbal cosmetics application might be effective method for facial skin elasticity.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.253-256
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• 2002

In this paper, we implement the volume pulse detection system which can quantitatively represent an artery elasticity. The system consists of transducer which has IRLED-photodiode detecter, temperature sensor, filters, preprocessing circuits, A/D converter, serial communication part and computer system. In order to presume the artery elasticity information we measure the volume pulse at four points and then evaluate the transition time, distance and the correlation coefficient of the pulse wave between the points. We test the system with 10 subjects during the week for basic experiment and obtain the data at four points. As the result of experiment, we can detect normalized volume pulse wave and evaluated parameter with effectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.343-347
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• 2005

As aging occurs, ow skin gets more wrinkles, becomes drier and loses its elasticity. Validating the evaluation of skin elasticity is especially important, because it is not as visible as other signs of aging such as wrinkles. Here, we identified the correlation between age and the Parameters given by Cutometer, and (we present) the parameters of that reflect the decreases in skin elasticity along with ages (Ur/Uf, Ua/Uf, Ur/Ue, Ua, $r=0.687{\sim}0.725$). Also we developed an evaluation method to quantify the difference of skin by viewing or touching. A five-grade standard of Moire topographic photo scale on face was prepared using sensory evaluation of 20 to 61 year - old women. Based on this photo standard, scoring was performed using (a) 5-grade system by three specialists to obtain the consensus score. Significant negative correlations between age and results of Cutometer $(r=-0.687{\sim}-0.725)$, Moire topography scores (r=-938) were found. Finally we have shown the significance of the correlation between the result of Cutometer and the score of Moire topography (r=0.711). Our studies using Moire topography on face have confirmed that instrumental measurements reflect the decrease in shin elasticity, which is perceived visually.

• Journal of Marine Bioscience and Biotechnology
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• v.10 no.2
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• pp.83-90
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• 2018

Ultraviolet (UV) radiation causes inflammation and matrix metalloproteinase (MMP) over-expression and extra cellular matrix depletion, leading to skin photo-aging such as wrinkle formation, dryness, and sagging. In this study, we demonstrated that pretreatment with the hexane extract of microalgae protects UVB mediated cell damages. The results of clinical study showed that Microalgal Oil treated group reduced wrinkle and improve elasticity. All these results suggest Microalgal Oil may be useful as new photo-aging cosmetics for protection against UV induced activity.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1613-1618
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• 2007

Mechanical characteristics of composite materials containing NiTi shape memory alloy(SMA) have been analyzed in this study by conducting tensile, photo-elasticity and impact tests for the specimens. From the test results, the SMA composite materials can be considered as one of possible ways in detecting and controlling damages in the materials.

• Journal of Applied Reliability
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• v.15 no.4
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• pp.270-275
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• 2015

Purpose : UHMWPE (Ultra-high-molecular-weight-polyethylene) is one of the most widely used material in knife protection clothes because of high strength, elasticity, and light weight. The purpose of this study is to develop the accelerated life test method and predict the lifetime for the knife protection fabric composed by UHMWPE. Methods : In this study, degradation characteristics of UHMWPE fibers and knife protection fabric for cut resistance were evaluated under the hydrolysis and photo-degradation conditions. It was found out that the degradation rate of retained tensile strength was more significant in the photo-degradation than hydrolysis. Therefore, the failure time was determined as the time that the retained tensile strength in photo-degradation is less than 50%. Considering an acceleration factor for irradiance and exposure time, the lifetime was predicted from the calculated failure time. Results : As a result of the accelerated life test, the $B_{10}$ lifetime of knife protection fabric composed by UHMWPE fibers is estimated as 2.8 years for a 90% statistical confidence level. Conclusion: Since the lifetime is predicted by the view-point of radiant exposure in this study, there is a possibility that the estimated lifetime may differ from the actual lifetime. However, it is considered as an useful methodology to estimate the long-term lifetime of knife protection fabrics.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.225-230
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• 2006

We have investigated mechanical behaviors of composite materials containing Ni-Ti shape memory alloy(SMA) wires by performing several experimental methods. In this study, several sample specimens were fabricated in order to perform photo-elasticity tests and impact tests under various test conditions for investigating the mechanical behaviors of the SMA composite materials. From the test results, the shape memory effect of SMA in composite materials can be considered as one of possible ways in controlling crack growth in the materials.

• Journal of Ginseng Research
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• v.40 no.3
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• pp.260-268
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• 2016

Background: During the aging process, skin shows visible changes, characterized by a loss of elasticity and the appearance of wrinkles due to reduced collagen production and decreased elasticity of elastin fibers. Panax ginseng Meyer has been used as a traditional medicine for various diseases due to its wide range of biological activities including skin protective effects. Ginsenosides are the main components responsible for the biological activities of ginseng. However, the protective activities of an enzymatic preparation of red ginseng against human skin aging have not been investigated. Methods: The efficacy of an enzyme-treated powder complex of red ginseng (BG11001) in preventing human skin aging was evaluated by oral administration to 78 randomized individuals. All patients were requested to take three daily capsules containing either 750 mg of BG11001 or a placebo vehicle for 24 wk; at the end of the testing period, skin roughness, elasticity, and skin water content were measured. Results: BG11001 significantly reduced the average roughness of eye wrinkles and the Global Photo Damage Score compared with the placebo, although there were no significant differences in arithmetic roughness average between the groups. In addition, gross elasticity and net elasticity values increased, and transepidermal water loss level decreased, indicating improved skin elasticity and moisture content. Conclusion: In conclusion, enzyme-treated red ginseng extract significantly improved eye wrinkle roughness, skin elasticity, and moisture content. Moreover, enzyme-treated red ginseng extract would be useful substance as a bio-health skin care product.

• Polymer(Korea)
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• v.36 no.4
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• pp.536-541
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• 2012

The effects of silica content were studied on UV curing characteristics and defect formations in imprinted patterns of hundreads nanometer size for the photo-curable imprinting composites with silica particles. An increase in elasticity and a decrease in shrinkage were observed with an increase in silica content in the imprinting resin which was UV cured at room temperature. However, the patterned nano-pillars were stuck together with neighboring nano-pillars if the amount of silica is more than 7 wt%. This can be ascribed to the increased viscosity of imperfectly cured resin due to the obstruction of the photo-reaction by silica particles. Addition of silica to the imprinting resin is useful in enhancing the strength of the cured resin although it is difficult to get good imprinted patterns for the resin with more than 7 wt% of silica due to the reduction of photo-reaction conversion.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.3
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• pp.288-299
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• 2003

Statement of problem: Many kinds of post and core systems are in the market, but there are no clear selection criteria for them. Purpose: The purpose of this study was to compare the flexural strength and modulus of elasticity of core materials, and measure the bending strength of post systems made of a variety of materials. Material and Methods: The flexural strength and elastic modulus of thirteen kinds core buildup materials were measured on beams of specimens of $2.0{\times}2.0{\times}24{\pm}0.1mm$. Ten specimens per group were fabricated and loaded on an lnstron testing machine at a crosshead speed of 0.25mm/min. A test span of 20 mm was used. The failure loads were recorded and flexural strength calculated with the measured dimensions. The elastic modulus was calculated from the slopes of the linear portions of the stress-stram graphs. Also nine kinds commercially available prefabricated posts made of various materials with similar nominal diameters, approximately 1.25mm, were loaded in a three-point bend test until plastic deformation or failure occurred. Ten posts per group were tested and the obtained data were anaylzed with analysis of variance and compared with the Tukey multiple comparison tests. Results: Clearfil Photo Core and Luxacore had flexural strengths approaching amalgam, but its modulus of elasticity was only about 15% of that of amalgam. The strengths of the glass ionomer and resin modified glass ionomer were very low. The heat pressed glass ceramic core had a high elastic modulus but a relatively low flexural strength approximating that of the lower strength composite resin core materials. The stainless steel, zirconia and carbon fiber post exhibited high bending strengths. The glass fiber posts displayed strengths that were approximately half of the higher strength posts. Conclusion: When moderate amounts of coronal tooth structure are to be replaced by a post and core on an anterior tooth, a prefabricated post and high strength, high elastic modulus core may be suitable. CLINICAL IMPLICATIONS In this study several newly introduced post and core systems demonstrated satisfactory physical properties. However when the higher stress situation exists with only a minimal ferrule extension remaining a cast post and core or zirconia post and pressed core are desirable.