• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1695-1700
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• 2014

Oriental herbal liquor (Yakju) is a type of Korean traditional alcoholic beverage that uses Nuruk and oriental herbs for fermentation. The purpose of this study was to develop cosmetic ingredients using Jubak, which is a by-product of alcoholic fermentation of oriental herbal liquor. To investigate antioxidant, whitening, and anti-aging effects of Jubak, we prepared extract of Jubak and its solvent fractions. Ethyl acetate fraction (KSD E4-3) showed the most prominent free radical [1,1-diphenyl-2-picrylhydrazyl (DPPH)] scavenging activity ($SC_{50}$: 0.75 mg/mL). KSD E4-3 significantly inhibited in vitro mushroom tyrosinase activity ($IC_{50}$: 0.82 mg/mL) and reduced the melanin contents in mouse melanoma melanocyte, B16F10 cells. KSD E4-3 down-regulated protein expression of tyrosinase related proteins (TRP)-1, -2, which play key roles in melanogenesis. For anti-aging effects, inhibition of matrix metalloproteinase (MMPs) expression was evaluated using human keratinocyte, HaCaT cells. Treatment of HaCaT cells with KSD E4-3 reduced expression of MMP-1, -2, -9 and inhibited proteolytic activities of MMP-2, -9. These results suggest that KSD E4-3 induces down-regulation of cellular melanogenesis and protects against photoaging induced by UVB-induced damage. Thus KSD E4-3 could potentially be a valuable cosmetic ingredient.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.182-188
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• 2016

A decoy is a weapon system that can protect vessels from an enemy's torpedo. Thus, the decoy should be able to operate in the field without any failure. Because the decoy can be inoperable once its sealing is broken and water permeates inside the system, the hermetic sealing capability considering the operational environment is mandatory. To be hermetically sealed, a rubber-type O-ring is generally used in a decoy system. The sealed performance of rubber-type products, however, tends to age and deteriorate with time. Therefore, the O-ring needs to be maintained or changed periodically. This paper proposes a method to estimate the proper maintenance period using the hardness and elongation percentage, which represents the performance of the O-ring product and test data from Accelerated Life Test (ALT) of the product. The O-ring used in this paper is a NBR type, and the temperature was chosen to be the main accelerating factor as referenced in many studies. The criteria for the failure of the O-ring was set for the product to be 50% degraded compared to the initial performance. In addition, the Korean standard KS M 6518 was adopted and referenced for the preparation of test samples and the calculation of estimates. The O-ring's predicted life was simulated by analyzing the test results from a computer program, and the optimized maintenance period for the product was determined.

• 한국노년학
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• v.29 no.4
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• pp.1261-1275
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• 2009

Age related decrease of muscle strength, balance, and gait abilities bring about physical inactivity in the elderly. Virtual reality (VR) training has been used successfully to rehabilitate functional balance and mobility in elderly subjects. This study was aimed at determining the effect of VR-based exercise programs by using a video game on the muscle strength, balance, and gait abilities in the elderly. 48 old people were randomly divided into two groups; VR-group (men: 11, women: 14, age: 68.42yrs) and control group (men: 10, women: 13, age: 67.58yrs). VR-group performed an exercise program twice a week for 8 weeks and control group had no intervention. The VR-based exercise program was composed of warm up(10 mins), VR-program(40 mins), and cool down(10mins). It was performed by playstation eyetoy play that provided visual and auditory feedback as well as movements of the upper and lower extremities. Muscle strengths of the knee and ankle were measured using manual muscle tester. Static balance was estimated using computerized posturography. Dynamic balance was measured by Timed up and go test (TUG), Functional reach test (FRT). 10m walk test and 6-min walk test were used to assess gait abilities. After the completion of the VR-exercise program, muscle strength, balance, and gait abilities were improved significantly (p<0.05). In conclusion, the VR-based exercise program showed improvement on the muscle strength, balance, and gait ability in the elderly. This exercise program is both effective and interesting for this age group.