• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.501-506
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• 2007

A generalized finite difference method for solving solid mechanics problems such as elasticity and crack problems is presented. The method is constructed in framework of Taylor polynomial based on the Moving Least Squares method and collocation scheme based on the diffuse derivative approximation. The governing equations are discretized into the difference equations and the nodal solutions are obtained by solving the system of equations. Numerical examples successfully demonstrate the robustness and efficiency of the proposed method.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.644-657
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• 2020

As the development of urbanization has cause some environmental problems and natural disasters such as natural earthquakes and floods have brought about impact, designers have turned their attention to the independent prevention ability of urban ecosystems in face of environmental pollution and natural disasters, as well as its ability to adapt to the future. This study introduces 'elasticity theory' to discuss the practical application of elasticity design in landscapes and to solve the problem of lack of elasticity in space, which can provide more scientific reference meaning to create economic, cultural, and social values for space. After selecting 'The High Line' as the object, this paper investigates the previous theories and practical cases, and infers ecology, sustainability, diversity, and adaptability. And then this paper applies five components and analyzes the specific application of these five components of the landscape spatial elasticity strategy, and summarizes the application characteristics and influencing factors of elasticity design in 'The High Line' landscape planning. It can be known from the research that elasticity strategy which is reflected in the design process is the systematic management of landscape space. Elasticity design itself can strengthen environment quality and satisfy the requirements of the environment to defense external shocks so as to adapt to environment changes. Therefore, the elasticity design can strengthen the sustainable development of the city and establish a periodic recycle system.

• Composites Research
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• v.23 no.3
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• pp.19-30
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• 2010

The present study describes a method for analytical solution to elastic field in structural elements of general symmetric laminated composite materials. The two dimensional plane stress elasticity problems under mixed boundary conditions are reduced to the solution of a single fourth order partial differential equation, expressed in terms of a single unknown function, called displacement potential function. In addition, all the components of stress and displacement are expressed in terms of the same displacement potential function, which makes the method suitable for any boundary conditions. The method is applied to obtain analytical solutions to two particular problems of structural elements consisting of an angle-ply laminate and a cross-ply laminate, respectively. Some numerical results are presented for both the problems with reference to the glass/epoxy composite. The results are highly accurate and reliable as all the boundary conditions including those in the critical regions of supports and loads are satisfied exactly. This verifies the method as a simple and reliable one as well as capable to obtain exact analytical solution to elastic field in structural elements of composite materials under mixed and any other boundary conditions.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.403-411
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• 2005

At present, the Cournot model is one of the most commonly used theories to analyze the gaming situation in an oligopoly type market. However, several problems exist in the successful application of this model to the electricity market. The representative one is obtaining the inverse demand curve able to be induced from the relationship between market price and demand response. In the Cournot model, each player offers their generation quantity to obtain maximum profit, which is accomplished by reducing their quantity compared with available total capacity. As stated above, to obtain the probable Cournot equilibrium to reflect the real market situation, we have to induce the correct demand function first of all. Usually the correlation between price and demand appears over the long-term through statistical data analysis (for example, regression analysis) or by investigating consumer utility functions of several consumer groups classified as residential, industrial, and commercial. However, the elasticity has a tendency to change continuously according to the total market demand size or the level of market price. Therefore it should be updated as the trading period passes by. In this paper we propose a method for inducing and updating this price elasticity of demand function for more realistic market equilibrium.

• Journal of Technologic Dentistry
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• v.36 no.3
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• pp.165-169
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• 2014

Purpose: This study is a mechanical strength supplementation of denture base resin Polymethyl methacrylate (PMMA) is in general use for denture base resin of the partial and full denture, however, The polymerization process of PMMA is not stabilized. Because of compatibility problems, preceding studies were performed, which were enhancing mechanical strength(Camilo Machado 2007),(Ana M. 2008), addition filler to materials property(Ayse Mese, 2008), self curing method(Hiroshi Shimizu, 2008). Methods: The carbon fiber and polyacetal filler, reinforced the mechanical strength for improving the stability of denture base resin were supplemented to the self cured resin. The Modulus of elasticity and the restoring force were calculated by tensile test. Results: The strengths of the heat and self cured resin were respectively decreased and increased, when the filler was supplemented to the denture base resin and the modulus of elasticity of both heat and self cured resin were not increased, when the filler was supplemented to the denture base resin. Conclusion: The restoring forces of self cured resin containing 10% filler were increased, when the filler was supplemented to the denture base resin.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.1
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• pp.37-43
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• 2014

The extended framework of Hamilton's principle provides a new rigorous weak variational formalism for a broad range of initial boundary value problems in mathematical physics and mechanics in terms of mixed formulation. Based upon such framework, a new variational numerical method of linear elasticity is provided for the classical single-degree-of-freedom dynamical systems. For the undamped system, the algorithm is symplectic with respect to the time step. For the damped system, it is shown to be accurate with good convergence characteristics.

• Structural Engineering and Mechanics
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• v.13 no.1
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• pp.103-116
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• 2002

A solution based on the linear three-dimensional theory of elasticity is developed for vibration and elastostatic problems of hollow toroids. The theory is developed for transversely isotropic toroids of arbitrary thickness, and has the potential to validate some vehicle and aircraft tire models in the linear range. In the semi-analytical method that is adopted Fourier series are written in the circumferential direction, forming a set of two-dimensional problems. These problems are solved using the differential quadrature method. A commercial finite element program is used to determine alternative solutions. For validation both problems of vibration and elastostatics are considered. Finally results are determined for local surface loading problems, and conclusions are drawn.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.684-697
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• 2021

This study seeks to establish the structural relationship between the personal psychological risk factors of teenagers of depression, anxiety and impulsiveness and smartphone addiction (daily disability, virtual orientation, tolerance, withdrawal) and self-elasticity (vitality, optimism, curiosity, interpersonal relationships). Through this verification, the purpose of this study is to find out if the integrated model of smartphone addiction and self-elasticity and smartphone addiction among teenagers is reasonable, and to suggest ways to prevent and solve smartphone addiction among teenagers. In order to achieve this purpose, 356 teenagers in Seoul and the metropolitan area were surveyed for two months from August to September 2019 and the results were analyzed. The findings of this study are as follows. First, the "smartphone addiction factors" (depression, anxiety and impulsive) of adolescents have been shown to have negative effects on their self-elasticity (vitality, optimism, curiosity, interpersonal relationships). Second, the "smartphone addiction factors" (depression, anxiety and impulsive) of teenagers have been shown to have positive effects on the "smartphone addiction" (daily disability, virtual orientation, tolerance, withdrawal). Third, the youth's "self-elasticity (vitality, optimism, curiosity, interpersonal relationship)" was shown to have a negative impact on "smartphone addiction (daily disability, virtual orientation, tolerance, withdrawal)." The significance of this study is that it has examined personal psychological risk factors that affect smartphone addiction and suggested measures to prevent smartphone addiction among teenagers and solve related problems by micro-analyzing the effects on smartphone addiction by utilizing self-elasticity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.39-47
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• 1997

Retinol as well as RA is well known to have many beneficial effects on aged skin. But the skin irritation potential and unstable condition of the products containing them have been some problems in their cosmetic uses. So, retinol containing gel product was developed for less skin irritancy and more stability in cosmetic products. To examine the clinical effects of retinlo containing product, we used cilnicla non-invasive assessment techniques on 40 volunteers for 6 months maintaining double-blind test conditions. According to our results, the use of retinol containing product improved skin color and hydration level slightly. But there was no statistical differences. There was no erythema reaction compared to the use of RA. Especially, the skin elasticity increased above 20% and skin wrinkles of crows' feet region decreased more than 10%. Besides the instrumental analysis, a large majority of volnteers felt that their skin were improved in the case of wrunkles, elasticity, hydration and color.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.643-648
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• 2002

A research for recycling the demolished-concrete as concrete aggregate has been concerned in all over the world. There, however, are some problems that qualities of recycled aggregates are not only largely different, but also mechanical properties of recycled aggregate concrete decrease a little in comparison with that of natural aggregate concrete. In this study, the resistance of freezing and thawing of concrete using source-concrete recycled aggregate(SRN) and demolished-concrete recycled aggregate(DRA) was investigated. Futhermore a research for improvement of freeze and thaw durability of recycled aggregate concrete was performed. Relative dynamic modulus of elasticity of SRN and DRA recycled aggregate concrete was dropped 60% before 150 of freezing and thawing cycle, and was much lower than that of control concrete. Relative dynamic modulus of elasticity of recycled aggregate concrete was increased to decrease water-cement ratio, but the freeze and thaw durability of recycled aggregate concrete was not enough improved. Futhermore, when metakaolin and silica fume were repalced, the freeze and thaw durability of recycled aggregate concrete containg metakaolin was more improved than that of silica fume.