• International Journal of Precision Engineering and Manufacturing
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• v.4 no.3
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• pp.62-67
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• 2003

The grinding force generated during the grinding process causes an elastic deformation of the workpiece, grinding wheel, and machine system. Thus, the true depth of cut is always smaller than the apparent depth of cut. This is known as machining elasticity phenomenon. The machining elasticity parameter is defined as a ratio between the true depth of cut and the apparent depth of cut. It is an important factor to understand the material removal mechanism of the grinding process. To increase productivity, the value of this machining elasticity parameter must be large. Therefore, it is essential to know the characteristics of this parameter. The objective of this research is to study the effect of the major grinding conditions, such as table speed, depth of cut, on this parameter experimentally, Through this research, it is found that this parameter value is increasing when the table speed is decreasing or the depth of cut is increasing. Also, this parameter value depends on the grinding mode (up grinding, down grinding).

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.929-935
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• 2011

Customers hardly change to electric prices in old days because electricity is essential commodity, while demand changes with price after deregulation. It's explained by price-based demand response with demand-elasticity matrix. Also all of the customers have had identical demand-price elasticity matrix till now. But in a practical power system, various customers are present with taking a variety of demand-price elasticity. Therefore this paper proposes demand-price sensitivity to represent different demand-price elasticity. Also as proposing demand-reliability sensitivity, it is modeling various customers' characteristics to reliability. And then this paper calculates total expected interruption cost of customer from the customer interruption cost and the demand-reliability sensitivity. A total expected interruption cost of system is shown as opportunity cost of a generation cost.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.199-208
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• 2022

Purpose : The study aimed to examine gender-differences in muscle tone, elasticity, and stiffness of the erector spinae in young and old subjects. This study also aimed to assess the effect of aging on muscle tone, elasticity, and stiffness of the erector spinae in men and women, and compare the trend of the aging effect between the two gender groups. Methods : With the muscle in the relaxed state and subjects in the prone position, a myotonometer was used to quantify muscle tone, elasticity, and stiffness, of the erector spinae in 102 participants[46 males (29 young subjects, aged 22.48±2.23 years and 17 old subjects, aged 76.35±3.71 years), 56 females (40 young subjects, aged 20.38±1.43 years and 16 old subjects, aged 74.56±5.40 years)]. Results : The tone and stiffness of the erector spinae muscles were greater in men than in women for both age groups (p<.001-.01), while elasticity did not show a significant difference between men and women. For the direction of change, both male and female groups showed significantly increased tone and stiffness, and decreased elasticity with increasing age (p<.001). For age-related changes, a different tendency was observed between men and women. Men showed a greater increase in tone than women with aging. in contrast, both men and women exhibited a similar decrease or increase in elasticity and stiffness. Conclusion : Gender-differences in the erector spinae in terms of muscle tone and stiffness were observed. Regardless of the age, men had higher muscle tone and stiffness than women, but not elasticity. The erector spinae muscles showed age-related changes in all aspects of muscle tone, elasticity, and stiffness, in both men and women. Notably, men presented greater variation than women in the amount of increase of muscle tone with aging. These findings have implications for musculoskeletal therapeutic approaches, and gender-customized tuning may be indicated for designing exercise interventions to prevent and manage gender-sensitive muscular injuries or diseases and frailty.

• 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 Labour Economics
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• v.39 no.2
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• pp.35-51
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• 2016

Using the Korea Labor and Income Panel Study (KLIPS) from 2000 to 2008, we estimate the Frisch elasticity of labor supply. Our point estimates of the intensive margin elasticity are around 0.23. The estimates are not sensitive to changes in household income and assets as well as changes in workweek regulation during the sample period that workers shall work for 5 days per week from Monday to Friday. We also estimate the extensive margin elasticity by considering labor market participation. We find that the point estimates at the extensive margin are greater than those at the intensive margin, but not statistically significant.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.335-343
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• 2014

To find out self elasticity of student of dental hygienic, how self elasticity influences life adaptation of college and study satisfaction. To structure analysis the effects that is given from self-elasticity of student of dental hygienic influences life adaptation of college and study satisfaction, from 2013/10/1 to 2013/10/31 due to convenience sampling, 369 students in grade 1,2,3 in Daegu Gyeongbuk were conducted a survey. The sub factors of self elasticity and study satisfaction and correlation of university life adjustment have the highest relevance to optimistic attitude and life adaptation of college. The higher self elasticity, the higher study satisfaction and the higher self elasticity and study satisfaction, the higher life adaptation of college. self elasticity increase the study satisfaction of students, improve adaptation(p<0.001). Therefore to promote the life adaptation of college, the effort and attention to reinforce the abilities of regulation of self elasticity that are an improvement of personal relation, goal setting, anger control and motivation. On this wise, development and management of suitable continuous and gradational educational programs are needed.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.296-306
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• 2021

Elasticity is a statistical technique that interprets the changing pattern of another variable according to a change in one variable as a quantitative numerical value and provides more information than correlation analysis and is widely used in climate change research. In this study the elasticity was calculated and sensitivity analysis was performed using air temperature and water quality data of the major tributaries of the Nakdong River. In addition the confidence interval for the elasticity was calculated using the T-Test and the validity of the elasticity was examined. The strength of elasticity shows high strength in the order of summer>fall>spring>winter and the direction shows regional characteristics with both negative and positive elasticity. After performing hierarchical cluster analysis on monthly observation data they were classified into 5 clusters and the characteristics of each cluster were visually analyzed using a parallel coordinate graph. The direction and intensity of the air temperature elasticity show regional characteristics due to the relatively high population density and complex influencing factors such as sewage treatment plants, small-scale livestock houses and agricultural activities. In the case of TP it shows great regional variability according to the circulation of nutrients in the ecosystem caused by algae growth and death according to temperature changes. Since the air temperature elasticity of the major tributaries of the Nakdong River is over weak and is valid at the significance level of 5%, it was analyzed that there is a change in water quality according to the air temperature change.

• 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.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.4
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• pp.38-46
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• 1993

This study is to analyze effect of exposure environment and mode of ASR on the engineering properties of synthetic lightweight aggregate concrete, such as dynamic modulus of elasticity and ultrasonic pulse velocity. The results of this study are summarized as foflows ; 1. The expansion rate of each exposure environment in 380$^{\circ}$C and NaCI 4% solution was shown higher than in 20$^{\circ}$C and normal water. The expansion rate of each exposure mode was largely shown in order of fjill immersion, wetting/drying, half immersion. 2. The dynamic modulus of elasticty and ultrasonic pulse velocity of each exposure environment in 38$^{\circ}$C and NaCl 4% solution was shown less than in 20$^{\circ}$C and normal water. The dynamic modulus of elasticity and ultrasonic pulse velocity of each exposure mode was shown smaller in order of full immersion, wetting/drying, half imersion.3. The relation between dynamic modulus of elasticity and ultrasonic pulse velocity was highly significant. The dynamic modulus of elasticity was increased with increase of ultrasonic pulse velocity. The decreasing rate of the dynamic modulus of elasticity was shown 2.1~3.4 times higher than the ultrasonic pulse velocity at each age, exposure environment and mode, respectively. 4. The expansion of each exposure environment and mode was increased with increase of curing age. The dynamic modulus of elasticity and ultrasonic pulse velocity of those concrete was increased with increase of curing age. At the curing age 28 days, the highest properties was showed at each type concrete, it was gradually decreased with increase of curing age. Specially, at the curing age 98 days of full immersion, the rate of expansion of type D was shown 3.95 times higher than the type A. But the dynamic modulus of elasticity and ultrasonic pulse velocity was decreased 17% and 8.3%.