• Korean Journal of Mathematics
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• 제7권2호
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• pp.245-269
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• 1999

Multigrid method and acceleration by conjugate gradient method for first-order system least squares (FOSLS) using bilinear finite elements are developed for various boundary value problems of planar linear elasticity. They are two-stage algorithms that first solve for the displacement flux variable, then for the displacement itself. This paper focuses on solving for the displacement flux variable only. Numerical results show that the convergence is uniform even as the material becomes nearly incompressible. Computations for convergence factors and discretization errors are included. Heuristic arguments to improve the convergences are discussed as well.

• Journal of Nutrition and Health
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• 제43권3호
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• pp.233-245
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• 2010

The purpose of this study was to investigate the effects of dietary habits and nutrient intakes on skin condition of female university students. The subjects were 95 female university students in Daegu. This study examined anthropometric measurements, dietary intake, food intake habits and skin condition (moisture, elasticity, sebum (U-zone, T-zone), pores, evenness and melanin pigmentation. The subjects in this study had an average age of 21.4, an average height and weight of 161.2 cm and 52.9 kg, respectively, and the average body mass index (BMI) was 20.3 $kg/m^2$. The means of skin elasticity, pores, evenness, and melanin pigmentation were within the normal range of women in their 20s and the skin moisture state was slightly lower than the normal range, which showed a dry tendency. The sebum in the U-zone and the T-zone was lower than the standard values, which showed less secretion in both areas. The subjects with high nut intake showed a better skin pore state (p < 0.05). Those with a high intake of instant foods showed a sig-nificantly low skin moisture and a significantly higher sebum rate (p < 0.05). The group with high skin elasticity and the group with less melanin pigmentation showed a significantly low animal protein intake (p < 0.05). The group with high skin elasticity also showed a significantly higher vitamin A and niacin intakes as well (p < 0.05). The group with high skin evenness showed a significantly lower animal lipid intake and a significantly higher vitamin E intake (p < 0.05). In addition, those with high skin elasticity and evenness as well as low melanin pigmentation showed a tendency of high intake of antioxidant vitamins, such as vitamin A, carotene, vitamin C or vitamin E. In summary, a moderate intake of plant-based products and also the antioxidant vitamins within such products seems to have a beneficial effect on maintaining a healthy and good skin condition.

• 대한한방부인과학회지
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• 제25권4호
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• pp.46-55
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• 2012

Objectives: It is well known that genetic factors and environmental factors play major role in aging skin. In general, son and daughter take after their parents in appearance. But comparability of skin properties in Korean family has not been well estimated. So we evaluated the correlation of skin properties in Korean mother-daughter pairs. Methods: 10 couples of mother and daughter pair(n=20) participate in this study. Mothers and daughters were aged $50.6{\pm}2.459$ and $23.8{\pm}2.15$ years, respectively. Skin moisture, sebum, skin color and elasticity is measured using non-invasive method : Corneometer CM825, Sebumeter(MPA580), Mexameter MX18, Cutometer MPA580. Statistical analysis program we used is Minitab 14 Korea. Results: The Skin moisture of mother group was significantly higher than daughter group. And skin elasticity(R2) of the daughter group was significantly higher than mother group. In the results of correlation analysis between mother and daughter pairs, skin elasticity(R2) had high positive correlation(r=0.729, p=0.026). But skin moisture, sebum, melanin index, erythema index and skin elasticity(R5) did not be confirmed a significant correlation. Conclusions: Skin elasticity(R2) is the only factor that showed high positive correlation significantly in mother and daughter pairs. Mother and daughter share the genetic factors and environmental factors that influence skin aging. So, mother's aging pattern will be a good guide for anti-aging of daughters.

• Computers and Concrete
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• 제15권5호
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• pp.795-805
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• 2015

In this study, dynamic modulus of elasticity of self-consolidating rubberized concrete is evaluated by using results of ultrasonic pulse velocity and resonance frequency tests. Additionally, correlation between dynamic modulus of elasticity and compressive strength results is compared. For evaluating the dynamic modulus of elasticity of self-consolidating rubberized concrete, prismatic specimens having $100{\times}100{\times}500$ mm dimensions are prepared. Dynamic modulus of elasticity values obtained by non-destructive measurements techniques are well agreed with those given in the literature.

• Journal of the Korean Wood Science and Technology
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• 제12권4호
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• pp.3-10
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• 1984

In hot pressed wood of Pseudotsuga menziesii compressed to 0 - 50 percent at temperature 60 - $180^{\circ}C$, relative humidity conditions affecting dynamic Young's modulus of elasticity and internal friction were investigated. The results obtained are summarized as follows: Moisture absorption of the hot pressed wood decreased with increasing press temperature, but there was no effect on the amount of compression. Thickness swelling dereased with increasing press temperature, and increased with increasing amount of compression. In general, dynamic Young's modulus of elasticity showed a straight line with increasing specific gravity of specimens. Dynamic Young's modulus of elasticity decreased with increasing moisture content, but internal friction increased with increasing amount of moisture content. Dynamic Young's modulus of R specimens pressed in the radial direction showed hight values than T specimens pressed in the tangential direction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.524-526
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• 2001

The variations of real time electric price in competitive electricity markets have influence on electric power demands of the consumers. Residential, commercial, and industrial consumers, with different characteristics cause the different price elasticity of the demand due to changing the pattern of consumption. Therefore, this paper calculate the elasticity of each loads and analysis the effects of electric power demands and spot pricing as a function of elasticity in competitive electricity market.

• 한방안이비인후피부과학회지
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• 제25권3호
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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.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5805-5810
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• 2011

본 연구는 피부 관리 측면의 노화방지 프로그램을 개발하는 기초자료를 제공할 목적으로 수기 요법과 저출력 레이저 요법을 이용하여 각각의 요법에 8명씩의 41세에서 58세 사이의 여성들에게 2011년 6월 20일부터 8월 26일까지 주 2회씩 4주 동안 총 8회에 걸쳐 안면 마사지를 시행하였다. 시행 2, 4, 6, 8회후 눈 밑과 볼의 피부 탄력도와 눈가와 볼의 멜라닌 양을 측정하여 평균값과 표준편차를 내고 비교 분석한 결과 두 집단 모두에서 탄력도가 유의적으로 증가하고 멜라닌양은 유의적으로 감소하는 결과가 나타났다. 또한, 탄력도의 증가율과 멜라닌양의 감소율 모두에서 수기 요법보다 저출력 레이저 요법이 더 효과가 높은 것으로 나타나 저출력 레이저 요법이 안면 피부의 탄력도와 멜라닌 양에 미치는 효과가 수기 요법보다 높은 것으로 분석되었다. 따라서 저출력 레이저를 이용한 피부 관리는 안면 피부의 노화방지에 유의하며 새로운 피부 관리의 프로그램으로 활용할 수 있을 것으로 분석되었다.

• 한국식생활문화학회지
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• 제21권3호
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• pp.254-261
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• 2006

The purposes of this study were to measure price elasticities of menu items of a family restaurant, identify differences of price elasticity between subgroups, and provide a comprehensive understanding on price elasticity. 3 menu items of a salad buffet family restaurant in Seoul were selected for analyses, and a questionnaire was developed through literature review and modified after pilot test. The questionnaires for main survey were distributed to 250 customers on their visit to the restaurant, and a total of 139 questionnaires were used for analyses (55.6%). Statistical analyses were conducted using SPSS Win (12.0) for descriptive analyses, t-test, ANOVA, and the main results of this study were as follows. The demands were expected very elastic to the changes in prices of all 3 menu items, and there were significant differences between groups of different company types. In addition, the changes in use were less affected by the changes in menu price when customers were satisfied with each menu item. On the basis of these results, it was concluded that price increases of menu items should be companied by quality improvement of products and services, and differentiated marketing strategy for each segments of customers would be helpful to profitability of the restaurant. Overall, measurement of price elasticity could help to predict customer behaviors on price changes, and give much useful information for managers and marketers of foodservice organizations in development of price strategies.

• 대한의용생체공학회:의공학회지
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• 제34권4호
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• pp.170-176
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• 2013

Lymphedema is a phenomenon in which fluid is accumulated inside tissues due to the damaged lymphatic systems. Lymphedema can cause complications such as lymphangitis, infection, changes in skin texture, fibrosis, and lymphangiosarcoma. In this study, a lymphedema screening system based on the elasticity of the skin is proposed to easily quantify lymphedema. The developed probe consists of touch sensors, a load cell and hall-effect sensors to measure the indentation force on the skin and the return time of the skin. The developed system can be used to estimate the change in the elasticity of the skin to quantify lymphedema. The system was tested with a thyroid phantom and gelatin phantoms of different concentrations and the resulting force and the time were recorded. It was found that the increase in the elasticity leads to a higher indentation force and shorter return time. This shows that the developed system can monitor the change in the skin elasticity by measuring the return time and the indentation force. The feasibility of the system in clinical applications will be evaluated in the future study.