• Steel and Composite Structures
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• v.31 no.1
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• pp.43-51
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• 2019

This paper is concerned with the numerical calculation of mixed-mode stress intensity factors (SIFs) of 2-D isotropic functionally graded materials (FGMs) by the natural element method (more exactly, Petrov-Galerkin NEM). The spatial variation of elastic modulus in non-homogeneous FGMs is reflected into the modified interaction integral ${\tilde{M}}^{(1,2)}$. The local NEM grid near the crack tip is refined, and the directly approximated strain and stress fields by PG-NEM are enhanced and smoothened by the patch recovery technique. Two numerical examples with the exponentially varying elastic modulus are taken to illustrate the proposed method. The mixed-mode SIFs are parametrically computed with respect to the exponent index in the elastic modulus and external loading and the crack angle and compared with the other reported results. It has been justified from the numerical results that the present method successfully and accurately calculates the mixed-mode stress intensity factors of 2-D non-homogeneous functionally graded materials.

• Korean Institute of Interior Design Journal
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• v.14 no.6 s.53
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• pp.103-111
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• 2005

Since the Industrial Revolution in the 18th century, the production system adopted mechanization and mass production to popularize and standardize overall society. The architectural space removed basic desire of men on the decoration to neglect historical and regional continuity of the architecture and to make uniform designs, so that human sensibility and emotion were excluded. The architectural space had arbitrary and functionalism features in accordance with such a social change to display abstract space having no personality. The limitation expanded value of the space that was not lot possession and residence but for communication with men to express object factors. However, the object factors of the space were expressed in each factor consisting of either material factors or non-material factors. This study investigated interaction of the space by both expressive interaction and potential interaction to find out key words for making frames of the investigation and to examine cases comprehensively. The purpose of the study was to recover relations between the space and men in horizontal way and mutual communication and to present possibility integrating men and space.

• Steel and Composite Structures
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• v.42 no.6
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• pp.779-789
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• 2022

This work presents a non-linear cylindrical bending analysis of functionally graded plate reinforced by single-walled carbon nanotubes (SWCNTs) in thermal environment using a simple integral higher-order shear deformation theory (HSDT). This theory does not require shear correction factors and the transverse shear stresses vary parabolically through the thickness. The material properties of SWCNTs are assumed to be temperature-dependent and are obtained from molecular dynamics simulations. The material properties of functionally graded carbon nanotube-reinforced composites (FG-CNTCRs) are considered to be graded in the thickness direction, and are estimated through a micromechanical model. The non-linear strain-displacement relations in the Von Karman sense are used to study the effect of geometric non-linearity and the solution is obtained by minimization of the total potential energy. The numerical illustrations concern the nonlinear bending response of FG-CNTRC plates under different sets of thermal environmental conditions, from which results for uniformly distributed CNTRC plates are obtained as benchmarks.

• KIEAE Journal
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• v.8 no.2
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• pp.65-70
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• 2008

Recently, there has been growing interest in barrier-free design which makes safe and convenient space for every pedestrian, not only the non-disabled but also the disabled. The purpose of this study is to suggest the data on the pavement materials of barrier-free pedestrian environment in view of universal design. In order to this, the research is focused on evaluating the visual preference and preference factors for pavement scenery, which can be changed by pavement materials. And this research is also comparing the visual preference and preference factors of the disabled with that of the non-disabled. A multi-regression analysis method is adopted to analyse the correlation between the visual preference for pavement scenery and preference factors in this study. The result of this analysis is as follows. Firstly, there are some differences of visual preference for the pavement material between the disabled and the non-disabled. Secondly, independent variables influencing on preference are similar between two groups. Thirdly, there are some differences in the priority of preference between the disabled and the non-disabled. This study will contribute to the field of barrier-free design and sustainable development projects in order to maximize the human being's satisfaction.

• Korea Journal of Hospital Management
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• v.28 no.4
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• pp.1-22
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• 2023

Purposes: The purpose of this study is to identify and analyze the factors that affect patients reusing non-face-to-face treatments at tertiary general hospitals. Methodology: We retrospectively analyzed a patient's reuse of non-face-to-face treatment from February 1, 2020, to December 31, 2021, at a tertiary general hospital in Seoul within one year of the first non-face-to-face treatment. A frequency analysis was conducted to identify the study subjects' demographic characteristics, treatment type characteristics, disease characteristics, and hospital use type characteristics. Also, across-analysis was conducted to verify the difference in non-face-to-face treatment reuse according to the characteristics a multiple logistic regression analysis was conducted to identify the factors affecting the reuse of non-face-to-face treatment by non-face-to-face treatment patients. Findings: The results of this study can be interpreted as indicating that the following groups are more likely tore use the non-face-to-face treatment: women, children, the elderly, Patients living far from the hospital, psychiatric patients, pediatric patients, medical benefits recipients, chronic patients, patients with mobility difficulties, and patients with high loyalty to hospitals. Practical Implications: When developing a non-face-to-face treatment system in the future, based on the results of this study, it is possible to target patients who prefer non-face-to-face treatment. And this study will be research material for vitalizing non-face-to-face treatment. In addition, the activation of the non-face-to-face treatment system will be an effective means for improving the quality of medical services and generating profits in hospitals in the future.

• Carbon letters
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• v.13 no.1
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• pp.23-28
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• 2012

Graphene is an attractive material for device applications, but device characteristics are very unstable because the graphene is very sensitive to environmental factors such as charges nearby the graphene, metal contacts, defects, contaminants and other adsorbates. Since the interactions between graphene and environmental factors affect the electrical characteristics of graphene devices, the interpretation of electrical characteristics as simple as current-voltage curves is non-trivial, despite the common practice of using well known electrical characterization methods that have been used in silicon MOSFET. This paper addresses major obstacles in the electrical characterization of graphene devices and offers countermeasures to improve the accuracy of electrical characterization methods.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.263-271
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• 1995

The purpose of this study nab to evlauate and compare the effect of the variable factors of wire on the elastic properties of looped rectangular wire. Five variable factors were presented-material(Hi-T, blue Elgiloy), wire size(.016'$\;\times\;$.022', .018'$\;\times\;$.025'), loop length(15mm, 20mm), loop configuration(open loop, closed loop), gabling (non-gable, gable). So, the total 256 specimens were divided into 32 groups, and each of those nab pulled on Instron testing machine. The load-deflection curve of each wire obtained, from which force, range in elastic limit, and stiffness were computed and analyzed statistically. The results were obtained as follows : 1. All of the variable factors - wire material, size, loop length loop configuration, and gabling - took a significant effect on load-deflection rate of looped wire. 2. The force at elastic limit was the smallest in the group of Hi-T, .016'$\;\times\;$.022', 20mm loop length, open loop, non-gable, and the largest in the group of blue Elgiloy, .018'$\;\times\;$.025', 15mm loop length, closed loop, non-gable. 3. The range at elastic limit was the smallest in the group of Hi-T, .018'$\;\times\;$.025', 15mm loop length, open loop, non-gable, and the largest in the group of HI-T, .016'$\;\times\;$.022', 20mm loop length, closed loop, gable. 4. Loop configuration and loop length were the most effective factors on the elastic properties of looped wires, and gabling was the least effective.

• Structural Engineering and Mechanics
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• v.22 no.5
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• pp.631-645
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• 2006

Buckling capacity of compression members may change due to inadvertent changes in the member section dimensions or material properties. This may be the result of repair, modification of section properties or degradation of the material properties. In some occasions, enhancement of buckling capacity of compression members may be achieved through splicing of plates or utilization of composite materials. It is very important for a designer to predict the buckling resistance of the compression member and the important parameters that affect its buckling strength once changes in section and/or material properties took place. This paper presents an analytical approach for determining the buckling capacity of a compression member whose geometric and/or material properties has been altered resulting in a multi-step non-uniform section. This analytical solution accommodates the changes and modifications to the material and/or section properties of the compression member due to the factors mentioned. The analytical solution provides adequate information and a methodology that is useful during the design stage as well as the repair stage of compression members. Three case studies are presented to show that the proposed analytical solution is an efficient method for predicting the buckling strength of compression members that their section and/or material properties have been altered due to splicing, coping, notching, ducting and corrosion.

• Journal of the Economic Geographical Society of Korea
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• v.8 no.2
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• pp.247-266
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• 2005

The purpose of this paper is to analyse the effects of a firm's financial and non-financial factors on the relationship formation with its main bank in the industry of parts and material in Pusan-Kyungnam region. The results, out of accordance with the relation-banking or regional financial market perspective, do not support the hypothesis that regional financial institutions would be useful for decreasing the financial difficulties of the small and medium firms in the region. The analyses about the effects of non-financial factors on the formation of main bank relations show that while Kookmin Bank and Industrial Bank play important roles as main banks of small businesses other national banks put emphasis on the transaction lending. And the analyses about the effects of financial factors show that firms having main bank relations with non-bank financial institutions and Kookmin bank are more profitable and stable than firms having main bank relations with other banks including local banks. On the whole it seems that local banks are not making a commitment to the regional economy and their operational grounds are not strong enough.

• Steel and Composite Structures
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• v.44 no.3
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• pp.353-369
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• 2022

This study attempts to shed light on the coupled impact of types of loading, thickness stretching, and types of variation of Winkler-Pasternak foundations on the flexural behavior of simply- supported FG plates according to the new quasi-3D high order shear deformation theory, including integral terms. A new function sheep is used in the present work. In particular, both Winkler and Pasternak layers are non-uniform and vary along the plate length direction. In addition, the interaction between the loading type and the variation of Winkler-Pasternak foundation parameters is considered and involved in the governing equilibrium equations. Using the virtual displacement principle and Navier's solution technique, the numerical results of non-dimensional stresses and displacements are computed. Finally, the non-dimensional formulas' results are validated with the existing literature, and excellent agreement is detected between the results. More importantly, several complementary parametric studies with the effect of various geometric and material factors are examined. The present analytical model is suitable for investigating the bending of simply-supported FGM plates for special technical engineering applications.