• Title/Summary/Keyword: and elasticity

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THE ANANLYSIS OF WILSON'S NONCONFORMING MULTIGRID ALGORITHM FOR SOLVING THE ELASTICITY PROBLEMS

  • KANG, KAB SEOK;KWAK, DO YOUNG
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.1 no.1
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    • pp.105-125
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    • 1997
  • In this paper we consider multigrid algorithms for solving elasticity problems by using Wilson's nonconforming finite element method. We consider two types of intergrid transfer operators which is needed to define the multigrid algorithm and prove convergence of $\mathcal{W}$-cycle mutigrid algorithm and uniform condition number estimates for the variable $\mathcal{V}$-cycle multigrid preconditioner.

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Analysis of Liver Elasticity according to Ultrasound Findings (초음파 소견에 따른 간 탄성도 분석)

  • Chun, Hye-Ri;Jang, Hyon-Chol;Cho, Pyong-Kon
    • Journal of the Korean Society of Radiology
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    • v.15 no.6
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    • pp.883-889
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    • 2021
  • This study was conducted on 101 patients who visited hospital for abdominal ultrasonography from May 2020 to December 2020. The purpose of this study was to find out the elasticity according to the ultrasound images (echo pattern, splenomegaly, hepatitis) during the ultrasound examination using the shear wave elastography. The shear wave elastography value of the normal group of the echo pattern was 5.75±1.58 kPa, and the group with the abnormal echo pattern was 8.84±4.94 kPa, and the shear wave elastography value of the abnormal group was high (p<0.05). In normal spleen size, hepatic elasticity value was 6.33±2.54 kPa, and hepatic elasticity value of splenomegaly was 13.73±5.48 kPa. In the case of splenomegaly, the liver elasticity value was high, and there was a statistically significant difference (p<0.05). As the spleen size increased, the liver elasticity value increased by 1.485 times, and as hepatitis progressed, the liver elasticity value increased by 1.573 times (p<0.05). As a result of analysis of concordance between ultrasound imaging findings and shear wave elastography, the Kappa value was found to be as high as 0.922 (p<0.05), which showed high concordance between the two test methods. Additional comparisons of liver elasticity values in shearwave elastography tests along with liver ultrasound findings are thought to be of great help in diagnosing liver fibrosis.

Basic Studies on the Native Colored-Soybean Cultivars III. Variations and Preformances in Chemical Composition and Textural Property in Seeds of Collected Colored-Soybean Cultivars (유색 대두수집종의 특성연구 제III보 유색 대두수집종의 화학적 조성과 특성 변이)

  • 구자옥;이종욱;이영만
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.3
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    • pp.345-350
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    • 1983
  • Collected 38 varieties of colored-soybean seed cultivated under a given cultural conditions were tested in the various chemical compositions and rheological properties in seeds. As it were, protein, fat, carbohydrate, ash and water contents as a chemical contents were studied not only on their statistical variations, but also on interrelationships with their collaborated rheological characteristics; hardness, cohesiveness, elasticity, gumminess and chewiness. For the rheological analysis of the materials, the General Foods Texturometer and typical texturometer curve were used.

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Investigation of masonry elasticity and shear moduli using finite element micro-models

  • Mavrouli, O.A.;Syrmakezis, C.A.
    • Smart Structures and Systems
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    • v.4 no.2
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    • pp.171-182
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    • 2008
  • In this paper, a methodology for the estimation of masonry elasticity and shear moduli is presented, for linear elasticity considerations. The methodology is based on the assumption that for a "periodic" masonry wall, which is formed by the repetition of a basic unit containing blocks and mortar, the mechanical characteristics of the unit are representative of the characteristics of the entire wall. For their calculation, the finite element analysis method is used. A micro-model with finite elements simulating separately the blocks and the mortar is developed. An equivalent finite element model, using an homogenous material is also developed and assuming equivalence of strains for the two models, the homogenous material properties are estimated. The efficiency of the method and its applicability limits are investigated.

A POSTERIORI ERROR ESTIMATOR FOR LINEAR ELASTICITY BASED ON NONSYMMETRIC STRESS TENSOR APPROXIMATION

  • Kim, Kwang-Yeon
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.16 no.1
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    • pp.1-13
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    • 2012
  • In this paper we present an a posteriori error estimator for the stabilized P1 nonconforming finite element method of the linear elasticity problem based on a nonsymmetric H(div)-conforming approximation of the stress tensor in the first-order Raviart-Thomas space. By combining the equilibrated residual method and the hypercircle method, it is shown that the error estimator gives a fully computable upper bound on the actual error. Numerical results are provided to confirm the theory and illustrate the effectiveness of our error estimator.

Forced vibration of nanorods using nonlocal elasticity

  • Aydogdu, Metin;Arda, Mustafa
    • Advances in nano research
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    • v.4 no.4
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    • pp.265-279
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    • 2016
  • Present study interests with the longitudinal forced vibration of nanorods. The nonlocal elasticity theory of Eringen is used in modeling of nanorods. Uniform, linear and sinusoidal axial loads are considered. Dynamic displacements are obtained for nanorods with different geometrical properties, boundary conditions and nonlocal parameters. The nonlocal effect increases dynamic displacement and frequency when compared with local elasticity theory. Present results can be useful for modeling of the axial nanomotors and nanoelectromechanical systems.

Buckling and bending analyses of a sandwich beam based on nonlocal stress-strain elasticity theory with porous core and functionally graded facesheets

  • Mehdi, Mohammadimehr
    • Advances in materials Research
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    • v.11 no.4
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    • pp.279-298
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    • 2022
  • In this paper, the important novelty and the defining a physical phenomenon of the resent research is the development of nonlocal stress and strain parameters on the porous sandwich beam with functionally graded materials in the top and bottom face sheets.Also, various beam models including Euler-Bernoulli, Reddy and the generalized formulation of two-variable beam theories are obtained in this research. According to a nonlocal strain elasticity theory, the strain at a reference point in the body is dependent not only on the stress state at that point, but also on the stress state at all of the points throughout the body. Thus, the nonlocal stress-strain elasticity theory is defined that can be actual at micro/nano scales. It can be seen that the critical buckling load and transverse deflection of sandwich beam by considering both nonlocal stress-strain parameters is higher than the nonlocal stress parameter. On the other hands, it is noted that by considering the nonlocal stress-strain parameters simultaneously becomes the actual case.

An Empirical Study on the Difference in Price Elasticity by Colors in the Chinese Mobile Phone Market (중국 핸드폰시장의 색상에 따른 가격탄력성 차이에 대한 실증연구)

  • Kwak, Youngsik;Hong, Jaewon;Pak, JiYoung
    • Journal of Platform Technology
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    • v.6 no.2
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    • pp.10-18
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    • 2018
  • The purpose of this study was to empirically analyze relations between color changes in the product specification and demand changes with price elasticity in the Chinese mobile phone market. In previous studies on price elasticity, the usual analysis units were product categories or SBU within a given product category. Unlike them, the this study set an analysis unit of price elasticity to focus on colors, which are investigated in the research fields of experiential marketing, aesthetic marketing, and cognitive psychology. Actual sales data according to the mobile phone price changes by the color were based on the sales volume of a sales agency at China's largest B2C site. The findings were as follows: first, price elasticity according to the six colors was higher than the absolute value of 1, which means that demands made flexible reactions to price changes. Secondly, there were differences in price elasticity according to the colors. Aroma white color made the smallest increase in sales volume at the same price discount, whereas diamond color made the biggest increase in sales in the same price discount scope. These findings indicate that more profit can be generated in mobile phone sales in China by setting different price discount or increase rates according to colors or producing different amounts of mobile phones according to colors. Distributors or sales agents can have a chance for higher profit by ordering and selling mobile phones in certain colors than others from mobile phone manufacturers. The academic findings indicates that there are differences in preference and price elasticity according to colors under the mobile phone category in the Chinese market, which means that the present study made an academic contribution by proposing a microscopic analysis unit for product price elasticity and expanding its concept.

Social welfare according to the Price elasticity of electric market participants (시장참여자의 가격탄력성에 따른 사회적 이득에 관한 연구)

  • Lee, Tae-Ho;Kim, Jin-O;Choi, Joon-Young
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.379-381
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    • 2000
  • In the new electric industry, many of generators and consumers exist in competitive market and electric price is determined by the response of suppliers and consumers. Power supply and consumption make change the electric price and social welfare depends on the elasticity that indicates sensitivity to changes of price related on the electric demand or supply. If elasticity is changed, social welfare that represents the sum of producers and customers surplus will be changed together. This paper investigates the change of the social welfare depending on the elasticity, and presents the propriety of competitive electric market.

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Price and Preference of Fisheries Imports : Utilization of Armington Elasticity (아밍턴 탄성치를 활용한 수입 수산물의 가격과 선호도 분석)

  • Byeong-Ho Lim
    • Korea Trade Review
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    • v.46 no.4
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    • pp.219-234
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    • 2021
  • Armington elasticity has been a methodology for analyzing how much imports could increase in response to importing price cuts, assuming the possibility of incomplete substitution of domestic and imported products. This study calculates Armington elasticity values in Korean fisheries sector and presents an analysis method for classifying items based on price and preference differences. The model is modified reflecting the characteristics of the fisheries market along with the typical OLS, PAM, and ECM models. The result's implication is that products with a high import growth rate do not necessarily show a high Armington value, but it could be seen that price is not the only factor facilitating fisheries imports increase. Considering the items of which demand increases due to importing price cuts have an indiscriminate demand between domestic and imported products, the results could be interpreted that the Korean fisheries importing market has been easily affected by the changes in import prices. Fisheries grouping by price and preference demonstrates that explanatory variables other than price should be considered when estimating import demand.