• Steel and Composite Structures
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• 제26권6호
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• pp.663-672
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• 2018

This paper contains a consistent couple-stress theory to capture size effects in Euler-Bernoulli nano-beams made of three-directional functionally graded materials (TDFGMs). These models can degenerate into the classical models if the material length scale parameter is taken to be zero. In this theory, the couple-stress tensor is skew-symmetric and energy conjugate to the skew-symmetric part of the rotation gradients as the curvature tensor. The material properties except Poisson's ratio are assumed to be graded in all three axial, thickness and width directions, which it can vary according to an arbitrary function. The governing equations are obtained using the concept of minimum potential energy. Generalized differential quadrature method (GDQM) is used to solve the governing equations for various boundary conditions to obtain the natural frequencies of TDFG nano-beam. At the end, some numerical results are performed to investigate some effective parameter on buckling load. In this theory the couple-stress tensor is skew-symmetric and energy conjugate to the skew-symmetric part of the rotation gradients as the curvature tensor.

• 대한가정학회지
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• 제40권4호
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• pp.139-152
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• 2002

This study was performed to estimate living cost for the elderly couple living in a city in Korea. Living cost means expenditure per month for elderly couple. It was assumed that the elderly couple will need different living cost according to their circumstances. The circumstances are health status, retirement status, and the level of living they want. The subjects were the elderly couple households over the age 65 of household head. Total number of subject was 1,649 households. Used data was Annual Report surveyed by National Statistical Office on the Family Income and Expenditure. Analysis of data was done through frequency, percentage, means, median using SAS Program. The results of this study were as follows: Their standard living cost was 844,980 won by pure relative standard line and 842,300 won by quasi relative standard lines. And minimum living cost was 713,400 won by the former, by the latter was 557,600 won (3/2 of median). And abundant Living cost was 1,068,020 won by the former, by the latter 1,263,450 won. The living cost of elderly households was about 81-83%, comparing with non-elderly households. Among the item of expenditure, the proportion of housing and medical care cost was larger than any other items.

• 한국사회복지학
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• 제45권
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• pp.101-125
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• 2001

In this study, we examine the marital factors which relate to the child abuse. We mainly analyze the influence of the satisfaction of couple life, communication on battering child, and we also test mediating effect of the level of parents' stress. The major outcomes of the study are following. In case of father, the satisfaction of couple life, communication don't have a significant influence on battering child. And they have a significant influence on the level of fathers' stress. But the level of fathers' stress does not influence on battering child. In case of mother, the satisfaction of couple life and communication don't explain the child abuse. But they have a significant influence on level of mothers' stress, and it also have a significant influence on battering child. These findings show that family therapy or marital therapy which focuses on enhancing the satisfaction of couple life and improving the way of communication between husband and wife is needed to reduce the child abuse. To the mothers, a stress management program can also be effective.

• Steel and Composite Structures
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• 제22권6호
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• pp.1239-1259
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• 2016

The modified couple stress-based third-order shear deformation theory is presented for sigmoid functionally graded materials (S-FGM) plates. The advantage of the modified couple stress theory is the involvement of only one material length scale parameter which causes to create symmetric couple stress tensor and to use it more easily. Analytical solution for dynamic instability analysis of S-FGM plates on elastic medium is investigated. The present models contain two-constituent material variation through the plate thickness. The equations of motion are derived from Hamilton's energy principle. The governing equations are then written in the form of Mathieu-Hill equations and then Bolotin's method is employed to determine the instability regions. The boundaries of the instability regions are represented in the dynamic load and excitation frequency plane. It is assumed that the elastic medium is modeled as Pasternak elastic medium. The effects of static and dynamic load, power law index, material length scale parameter, side-to-thickness ratio, and elastic medium parameter have been discussed. The width of the instability region for an S-FGM plate decreases with the decrease of material length scale parameter. The study is relevant to the dynamic simulation of micro structures embedded in elastic medium subjected to intense compression and tension.

• Nuclear Engineering and Technology
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• 제43권2호
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• pp.159-166
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• 2011

Si-rich-layer-coated U-7 wt%Mo plates were prepared in order to evaluate the diffusion barrier performance of the Si-rich layer in U-Mo vs. Al interdiffusion. Pure Si powder was used for coating the U-Mo plates by annealing at $900^{\circ}C$ for 1 h under vacuum of approximately 1 Pa. Si-rich layers containing more than 60 at% of Si were formed on U-7 wt%Mo plates. Diffusion couple tests were conducted in a muffle furnace at $560-600^{\circ}C$ under vacuum using Si-rich-layer-coated U-Mo plates and pure Al plates. Diffusion couple tests using uncoated U-Mo plates and Al-(0, 2 or 5 wt%)Si plates were also conducted for comparison. Si-rich-layer coatings were more effective in suppressing the interaction during diffusion couple tests between coated U-Mo plate and Al, when compared with U-Mo vs. Al-Si diffusion couples, since only small amounts of Al in the coating could be found after the diffusion couple tests. Si-rich-layer-coated U-7wt%Mo particles were also prepared using the same technique for U-7 wt%Mo plates to observe the microsturctures of the coated particles.

• 한국가족관계학회지
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• 제22권3호
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• pp.3-27
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• 2017

Objectives: This study examined the effects of married couple's sexual satisfaction on perceived family strengths based on family systems theory that the changes of family subsystem could extend itself to involve the entire family system. Methods: For this purpose, the structured survey was conducted by 151 married couples living in Jeollanam-do and Gwangju. The data was analysed by SPSS 21.0 program. Results: First, the average scores of family strengths and sexual satisfaction were a little higher than the middle. There were no differences between husbands and wives. Second, family strengths perceived by husbands were significantly affected by income satisfaction, conflicts and sexual satisfaction. In wives, education level, satisfaction with communication times, conflicts and sexual satisfaction were influential factors. Conclusion: It is necessary to pay the most attention to sexual satisfaction of couples in order to improve family strengths. In addition, it is actually required to develop various couple programs about enhancing sexual satisfaction related to the effective couple communication and problem-solving methods. It also have to imply the requirements considering characteristics of male and female, husbands and wives.

• Geomechanics and Engineering
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• 제21권5호
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• pp.461-469
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• 2020

The objective of this paper is to study the deformation in a homogeneous isotropic modified couple stress thermoelastic medium with and without energy dissipation and with two temperatures due to thermal source and mechanical force. Laplace and Fourier transform techniques are applied to obtain the solutions of the governing equations. The displacement components, stress components, conductive temperature and couple stress are obtained in the transformed domain. Isothermal boundary and insulated boundary conditions are used to investigate the problem.The effect of two temperature and GN theory of type-II and type-III has been depicted graphically on the various components. Numerical inversion technique has been used to obtain the solutions in the physical domain. Some special cases of interest are also deduced.

• Computers and Concrete
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• 제19권6호
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• pp.701-710
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• 2017

In this study, the thermoelastic beam in modified couple stress theory due to laser source and heat flux is investigated. The beam are heated by a non-Guassian laser pulse and heat flux. The Euler Bernoulli beam theory and the Laplace transform technique are applied to solve the basic equations for coupled thermoelasticity. The simply-supported and isothermal boundary conditions are assumed for both ends of the beam. A general algorithm of the inverse Laplace transform is developed. The analytical results have been numerically analyzed with the help of MATLAB software. The numerically computed results for lateral deflection, thermal moment and axial stress due to laser source and heat flux have been presented graphically. Some comparisons have been shown in figures to estimate the effects of couple stress on the physical quantities. A particular case of interest is also derived. The study of laser-pulse find many applications in the field of biomedical, imaging processing, material processing and medicine with regard to diagnostics and therapy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.44-46
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• 2008

This paper Proposes a new couple particle swarm optimization (CPSO) for multimodal functions. In this method, main particles are generated uniformly using Faure-sequences, and move accordingly to cognition only model. If any main particle detects the movement direction which has local optimum, this particle would create a new particle beside itself and make a couple. After that, all couples move accordingly to conventional particle swarm optimization (PSO) model. If these couples tend toward the same local optimum, only the best couple would be kept and the others would be eliminated. We had applied this method to some analytic multimodal functions and successfully locate all local optima.

• 대한가정학회지
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• 제29권3호
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• pp.35-45
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• 1991

This study was to calculate the minimum food expenditure by using OR linear program, and to determine the food plans for different income values based on the recommenced dietary allowances(RDA) for Koreans. VAX 11/780 system was used in this study. There were 6 family models-single man, single woman, married couple, couple with one child, couple with 2 children and couple with 2 children & grandmother. The market price quoted in this study was from July 1989 to June 1990 and the data file was made from RDA & food composition tables. After the minimum food expenditure was calculated from the computer, the low cost food plan was set. From the low cost food plan, we set the moderate cost food plan 25% above the low cost and the liberal food plan 50% above the low cost. One week menu was planned for different food plans. The low cost food plan could be used not only at the institutional levels and at home but also used at the national food policy making for scientific budget planning and for nutritionally well balanced diet. These food plans could control the use of time and efforts, too.