• Journal of Korea Multimedia Society
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• v.25 no.9
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• pp.1307-1315
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• 2022

In this paper, we proposed and developed a new portable skin elasticity measuring device based on the indentation method using piezoelectric effect. The proposed device is designed to minimize the uncertainty caused by the layer structure of the skin when measuring the elasticity of the skin. And, we developed a piezoelectric-based thin-film pressure sensor that can measure quantitatively and quickly during repeated measurement as a device sensor. To confirm the effectiveness of the proposed measuring device, it was compared with the experimental results of the conventional measuring devices under the same experimental conditions, and statistical correlation analysis was performed between the experimental data of the proposed measuring device and the experimental data of the conventional measuring devices. As a result of the correlation analysis, it was confirmed that the proposed measuring device had a high correlation with the conventional measuring devices. Therefore, it was confirmed that the proposed skin elasticity measuring device was effective.

• Korean Journal of Oriental Medicine
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• v.16 no.3
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• pp.135-140
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• 2010

The usefulness of constitutional diagnoses based on skin measurements has been established in oriental medicine. According to Sasang constitutional medicine, humans can be distinguished based on properties of skin's friction, thickness and elasticity. To quantify and standardize skin diagnosis, the present study designed an equipment for measuring skin elasticity of hand. But there were some noises in measuring skin elasticity such as measurement method, environment, operator and conditions of patient. So we considered a six sigma project for reducing the measurement errors. The project was followed to discipline process of five macro phases: Define, Measure, Analyze, Improve and Control(DMAIC). So, we could find the major factors which should be controled for stabilizing measurement system and we revised the SOP(Standard Operating Procedure) of the skin elasticity measurement.

• Journal of Labour Economics
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• v.34 no.3
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• pp.1-28
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• 2011

This paper empirically tests the theory that labor demand elasticity of unionized firms would be smaller than that of nonunionized firms, using the Korean firms' panel data for 1990-2009. The major findings are the following: First, the estimates of labor demand elasticity of unionized firms are in the range of 0.34-0.49, less than a half of those of nonunionized firms, hence supporting the theory. Second, the unionized firms are more rigid in dynamic adjustment of employment than nonunionized firms. Finally, there are no significant differences between unionized and nonunionized firms in the elasticity of substitution.

• Journal of the Korea Concrete Institute
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• v.12 no.6
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• pp.23-34
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• 2000

This paper reports the effects of curing temperature and aging on the strength and the modulus of elasticity. In oder to determine the strength and the modulus of elasticity with curing temperature and aging, experimental and analytical methods are adopted. The tests of 480 cylinders are carried out for type I, V and V with 15 percent replacement of fly ash cement concretes, which are cured at isothermal conditions of 10, 23, 35 and 5$0^{\circ}C$. and the concrete cylinders are tested at the ages of 1, 3, 7 and 28 days. According to the experimental results, the concrete subjected to high temperature at early ages attaines higher early-age compressive and splitting tensile strength but eventually attaines lower later-age compressive and splitting tensile strength. Even if modulus of elasticity has the same tendency, the variation of modulus of elasticity with curing temperature is smaller than that of compressive strength. Based on these experimental results, the relationships among compressive strength, modulus of elasticity and splitting tensile strength are proposed considering the effects of curing temperature, aging and cement type.

• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.148-155
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• 2009

The objective of this study is to know market structures of softwood logs being imported to South Korea from log producing countries. Import demand of softwood logs imported to South Korea from America, New Zealand and Chile is fixed as a function of log prices, the lagged dependent variable and output. On the basis of the adaptive expectations model, linear regression models that the explanatory variables included and the lagged dependent variable were estimated by Seemingly Unrelated Regression Equations (SURE). The short-run and long-run own price elasticity of America's softwood log import demand is -1.738 and -4.250 respectively. Then long-run elasticity is much higher than short-run elasticity. Short-run and long-run crosselasticity of New Zealand's softwood log import demand with respect to American's softwood log import price are inelastic at 0.505 and 0.883 respectively. Short-run and long-run cross-elasticity of Chile's softwood log import demands with respect to American's softwood log import prices were highly elastic at 2.442 and 4.462 respectively. Long-run elasticity was almost twice as high as short-run elasticity.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.130-137
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• 2014

Nondestructive evaluation (NDE) method by using a resonance frequency mode was carried out for ceramics made from particle boards with different phenol resin impregnation ratios (30, 40, 50, 60%) at carbonizing temperature of $800^{\circ}C$. The material for ceramics was Miscanthus sinensis var. purpurascens board. Dynamic modulus of elasticity increased with increasing impregnation ratio. There was a close relationship of dynamic modulus of elasticity and static bending modulus of elasticity to modulus of rupture (MOR). However, the result indicated that correlation coefficient is higher in dynamic modulus of elasticity to MOR than that in static modulus of elasticity to MOR. Therefore, the dynamic modulus of elasticity using resonance frequency by free vibration mode is more useful as a nondestructive evaluation method for predicting the MOR of ceramics made from Miscanthus sinensis var. purpurascens particle boards by different phenol resin impregnation ratios.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.573-584
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• 2012

Breast and prostate tumors or cancers tend to be stiffer than the surrounding normal tissue. However, the difference in echogenicity between cancerous and normal tissues is not clearly distinguishable in ultrasound B-mode imaging. Thus, imaging the stiffness contrast between the two different tissue types helps to diagnose lesions quantitatively, and such a method of imaging the elasticity of human tissue is termed ultrasound elasticity imaging. Recently, elasticity imaging has become an effective complementary diagnostic modality along with ultrasound B-mode imaging. This paper presents various elasticity imaging methods that have been reported up to now and describes their characteristics and principles of operation.

• Health Policy and Management
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• v.17 no.3
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• pp.50-67
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• 2007

This study investigated income elasticity of household health expenditures and differences by income level from 1998 through 2003. Data from Korean Labor and Income Panel Study was used for empirical analyses. To estimate the income effects on health expenditure, the two-part model was employed: a logistic regression for any health expenditure-first part-and a Ordinary Least Square regression for health expenditure conditional on any spending-second part. To estimate income elasticity, both health expenditure and income were log transformed in the second part. In addition, the random effects(RE) model was used for a longitudinal panel which was continuously followed from 1998 through 2003 to estimate income effects on health expenditures controlling for within and between unobservable household characteristics. Furthermore, difference in income effects on health expenditure across income level was investigated. Although income slightly increased odds of any health expenditure, there was not no table differences across income level. Income significantly increased health expenditures during study period(overall income elasticity: about 0.2) and the highest 20% income group presented higher income elasticity than the lowest 20% income group.

• Archives of Craniofacial Surgery
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• v.20 no.3
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• pp.158-163
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• 2019

Background: Age-related changes in facial skin is a major concern in women. This study aimed to objectively evaluate normal skin elasticity and age-related differences in the faces of East Asian women. There are no standard values for data related to normal skin on East Asian women. Methods: We studied 129 healthy East Asian women without a history of cosmetic procedures or surgeries. Skin elasticity was assessed at the cheek and lower eyelid points, which were assessed on both the right and left sides of the face. Results: The age of the subjects showed significant negative correlations with the R2 and R7 parameters, which represent skin elasticity after deformation. Conclusion: We therefore concluded that the primary decrease in skin elasticity in East Asian women occurs in the midface region.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.4
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• pp.77-87
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• 2023

PURPOSE: The purpose of this study was to investigate the changes in the flexibility and elasticity of the muscles when the hamstrings were stretched in one direction and when they were stretched in three directions. METHODS: In this study the subjects were divided into two groups, namely the 'one-direction stretching exercise of the hamstring muscle in the neutral position' group (female: 14 people, male: 14 people) and the 'three-way stretching exercise' group (female: 12 people, male: 14 people) considering the positions of the three hamstring muscles. The elasticity and flexibility of the hamstring muscles were measured before and after the self-extension exercise, and the average value of two measurements was noted. To evaluate the flexibility of the hamstring muscle, a 'sit and reach' test was performed, and muscle elasticity was measured using the MyotonPRO® device. RESULTS: After the stretching exercise, flexibility increased in both groups. In terms of muscle elasticity, the body dynamic strength and resonance frequency of the stretching one-direction stretching group decreased after the stretching exercise. CONCLUSION: To alter the muscle characteristics and increase the flexibility when performing a stretching exercise, selecting and stretching only one muscle with the lowest range of motion yields effective results. The ideal technique to be employed appears to be to stretch the entire hamstring muscle in one direction from the neutral position.