• Steel and Composite Structures
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• v.50 no.5
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• pp.563-581
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• 2024

This paper presents a novel finite element model for the free vibration analysis of variable-thickness functionally graded porous (FGP) microplates resting on Pasternak's medium in the hygro-thermal environment. The governing equations are established according to refined higher-order shear deformation plate theory (RPT) in construction with the modified couple stress theory. For the first time, three-node triangular elements with twelve degrees of freedom for each node are developed based on Hermitian interpolation functions to describe the in-plane displacements and transverse displacements of microplates. Two laws of variable thickness of FGP microplates, including the linear law and the nonlinear law in the x-direction are investigated. Effects of thermal and moisture changes on microplates are assumed to vary continuously from the bottom surface to the top surface and only cause tension loads in the plane, which does not change the material's mechanical properties. The numerical results of this work are compared with those of published data to verify the accuracy and reliability of the proposed method. In addition, the parameter study is conducted to explore the effects of geometrical and material properties such as the changing law of the thickness, length-scale parameter, and the parameters of the porosity, temperature, and humidity on the free vibration response of variable thickness FGP microplates. These results can be applied to design of microelectromechanical structures in practice.

• Journal of Families and Better Life
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• v.20 no.3
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• pp.73-85
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• 2002

The purpose of this study was to develop and evaluate the Marital Equality Education Program for women farmers and their husband. Based on the empirical research result of 980 women farmers as basic study for developing this program, marital equality theory, system theory, strong family perspective, stress coping theory, anger control theory, modified Couple Communication Program, marriage enrichment methods, 7 session program was developed. The contents of every session were Reviewing Marriage Relationships, Coping Role Stress, Marital Equality, Self Expression & Speaking, Understanding Spouse & Listening, Anger Control& Resolving Conflict, and Enhancing Marital Relations. The effectiveness of this program was evaluated by pretest, post test, and follow-up 1 month later through 35 rural couples(women farmers and their husband) and it was analyzed by paired t-test and qualitative evaluation was also investigated. The major results were as follows : This program was effective in improving their self-esteem, marital satisfaction, coping role stress & conflicts, and husband's egalitarian role attitude & practice. The results suggested the program had also Positive impacts on the marital equality and relationships. Future research and practical implications were added.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.1-8
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• 2013

This study was performed for the purpose of analyzing the effect of tide on the stress-strain behavior in the boundary surface of sea dike embankment. Tide is a dynamic condition, but there are not suitable numerical models to solve the dynamic embankment condition caused by tide. So the analysis was simplified to quasi dynamic as follow. First, seepage by tide was analyzed according to elapsed time, and the results of the analysis at every hour during one periodic cycle time of 12 hours were applied to the pore water pressure conditions of stress-strain analysis with hyperbolic model by Duncan and Chang. The place at which maximum shear strain took place in the analysis result moved up and down repeatedly along the boundary of the dredged sand fill section and the crashed stone filter section. The value of maximum shear strain was large at high water level of tide. This result means that contraction and relaxation occur in turn repeatedly at every specific position along the boundary, and the repeated action compact loose position with sand moved down from the upper position by gravity. The experiment with the small sea dike model showed the result consistent with the numerical analysis. The surface of sea side on the dike collapsed at high water level after a couple of repetition of the rising and falling of water.

• Geomechanics and Engineering
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• v.25 no.2
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• pp.75-87
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• 2021

Because the hydraulic/mechanical behaviour of unsaturated soil is more complicated than that of saturated soil, one of the most important issues in modelling unsaturated soil is to properly couple its stress-strain relationship with its water retention characteristics. Based on the results of a series of tests, the stress-strain relationship and the changes in suction and saturation of unsaturated completely decomposed granite (CDG, also called Masado) vary substantially under different loading/hydraulic conditions. To precisely model the hydraulic/mechanical behaviour of unsaturated Masado, in this study, the superloading concept was firstly introduced into an existing saturated/unsaturated constitutive model to consider the structural influences. Then a water retention curve (WRC) model considering the volumetric change in the soil, in which the skeleton and scanning curves of the water retention characteristics were assumed to shift in parallel in accordance with the change in the void ratio, was proposed. The proposed WRC model was incorporated into the constitutive model, and the validity of the newly proposed model was verified using the results of tests conducted on unsaturated Masado, including water retention, oedometer and triaxial tests. The accuracy of the proposed model in describing the stress-strain relationship and the variations in suction and saturation of unsaturated Masado is satisfactory.

• Journal of the Korean Home Economics Association
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• v.35 no.5
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• pp.73-102
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• 1997

The purpose of this study was to identify the specific and empirical contents in terms of first-married stepmother about her stress and efforts to adapt to her stepfamily. This studies relied on the qualitative research method in order to approach stepmother's subjective experience. There were 6 stepmother respondents who were 6 first-marrieds living in Seoul or Kyoungki area. The data was collected by in-depth personal interview.‘Open coding process’, a part of grounded theory procedures were used to analyzed the data. The major findings can be summarized as follows: 1. When focused o stressors, the stress of stepmothers were categorized into 4 categories. Those were the following: 1 When focused on stressors, the stress of stepmothers were categorized into 4 categories. Those were the following: (1) Stepmother's own problem such as stepmother' identity problem; (2) Problems within stepfamily such as problems about relations with husbands, stepchildren, and her own children; (3) Problems of stepmother family's kin such as relational problems with former spouses, in-laws, and her parent; (4) Problems of social relationship such as isolation and alienation in social relationship and neighbors' prejudice about stepmother. 2. In overcoming stress from stepfamily life and adapting to it, 4 categories were identified as important. Contents of 4 categories were such like this: (1) Stepmother's own efforts - (a) give a positive meaning to marriage or remarriage (b) flexible personality (c) situation-accepting attitude (d) exclusive management of household income (e) job (f) perseverance for time to adaptation; (2) Positive feedback within stepfamily - (a) supportive husband (b) sense of unity as a couple (c) psychological reward from stepchildren (d) existence of stepmother's own child (e) behavior for family solidarity (f) family-centered religious life; (3) Stepfamily's relationship with former spouses such as breakdown in relationship with ex-wives or ex-husbands; (4) Support from stepmothers' kin and people in social network with stepmothers. It was concluded that to reduce stress and to help adapt to stepfamily, stepmother should make an effort, and that her stepfamily and her kin should cooperate and support. In addition, negative stereotype of stepmother and stepfamily should disappeared. It was suggested that studies on stepfamily should be vitalized and that programs for preparing remarriage and counseling for stepfamily should be spread.

• Journal of the Korean Home Economics Association
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• v.43 no.10 s.212
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• pp.55-68
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• 2005

This research focused on the family stress, coping strategy, and job satisfaction in dual-earner couples. The subjects of this study were 150 dual-earner couples,300 people, in the Kyeongnam Area, Korea. The major findings from the study are as follows; 1) The degree of family stress of the husband and wife in dual-earner couples was 2.74 and 2.98, respectively, on a scale of 0-5.0. The most stressful event arose from their role as parents caring for their children. The significant variables were religion and the type of expended family in dual-earner couples' husband, and the age of the first child, job, economic level, conjugal period, and marital satisfaction in dual-earner couples' wife. 2) The coping strategy of family stress of the husband and wife in dual-earner couples was 3.41 and 3.45, respectively, on a scale of 0-5.0. Among the strategies, the 'cognitive restructuring' scored highest. The significant variables were religion, the degree of educational level, job, marital satisfaction, and self-esteem in dual-eamer couples' husband, and economic level, the type of expended family, marital satisfaction, and selfesteem in dual-earner couples' wife. 3) The degree of job satisfaction of the husband and wife in dual-earner couples was 3.72 and 3.89, respectively, on a scale of 0-5.0. The most effective variables of job satisfaction of the husband and wife in dual-earner couples was self-esteem and cognitive restructuring strategy, respectively.

• The Journal of Korean Obstetrics and Gynecology
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• v.36 no.3
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• pp.114-128
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• 2023

Objectives: This study was conducted to reflect Korean Medicine doctors (KMD)' perception of lifestyle management in the process of developing a Korean Medicine (KM) Clinical Practice Guidelines (CPG) of female infertility. Methods: We sent four e-mails containing links to online questionnaires to 25,286 KMD belonging to the Association of Korean Medicine. The questionnaire consisted of sexual intercourse, weight, diet, exercise, drinking, smoking, caffeine intake, stress etc. KMD responded to self-administered questionnaires, and we analyzed 786 responds. Results: KMD put stress first among the infertile women's lifestyle management items, weight and sexual intercourse were next. Also KMD put stress first among the spouses' lifestyle management items, drinking and sexual intercourse were next. In relation to sexual intercourse, 'Recognizing the Fertile Window' was the most important. In relation to stress in the emotional domain, 'Depression' and 'Anxiety' were the most important, and in relation to stress in the relationship domain, 'Deteriorating of marital relationship' was the most important. Conclusions: We surveyed the status of KMD' awareness of infertility lifestyle management for patient education, and reflected it in the modification of the CPG for female infertility.

• Advances in Computational Design
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• v.2 no.2
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• pp.147-168
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• 2017

Over the past couple decades, externally bonded fiber reinforced polymer (FRP) composites have emerged as a repair and strengthening material for many concrete infrastructure applications. This paper presents an analytical investigation of the use of carbon FRP (CFRP) for a specific problem that occurs in concrete bridge girders wherein the girder ends are damaged by excessive exposure to deicing salts and numerous freezing/thawing cycles. A 3D finite element (FE) model of a full scale prestressed concrete (PC) I-girder is used to investigate the effect of damage to the cover concrete and stirrups in the end region of the girder. Parametric studies are performed using externally bonded CFRP shear laminates to determine the most effective repair schemes for the damaged end region under a short shear span-to-depth ratio. Experimental results on shear pull off tests of CFRP laminates that have undergone accelerated aging are used to calibrate a bond stress-slip model for the interface between the FRP and concrete substrate and approximate the reduced bond stress-slip properties associated with exposure to the environment that causes this type of end region damage. The results of these analyses indicate that this particular application of this material can be effective in recovering the original strength of PC bridge girders with damaged end regions, even after environmental aging.

• Journal of Families and Better Life
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• v.22 no.2
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• pp.69-83
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• 2004

The purpose of this study was to investigate the family stresses and its managing strategy to cope with the stresses, and family strengths among commuting couples. The participants of this study consisted of a national samples of 134 couples (268 individuals), whose has been commuting for at least six months The major findings obtained from the study are summarized in the following: 1) The degree of family stresses among commuting couples was 2.98, when the maximal stress value was set to 5.0. The most stressful aspect for the commuting couples came from the role of parents who care for their children. 2) The degree of coping strategy among commuting couples was 3.37, when the maximal coping strategy value was set to 5.0. Among the strategies, the 'cognitive restructuring' shows the first. 3) The degree of family strengths among commuting couples was 3.76, when the maximal strengths value was set to 5.0. Also factors affecting the family strengths among commuting couples are dependent on their educational degree, religion, kind of jobs, commuting and conjugal periods, moving person, meeting frequencies, self-esteem and marital satisfaction. 4) The most effective variable of family strengths among commuting couples was marital satisfaction.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1541-1555
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• 2015

In this paper mechanical behavior of the functional gradient materials (FGM) micro-gripper under thermal load and DC voltage is numerically investigated taking into account the effect of intermolecular forces. In contrary to the similar previous works, which have been conducted for homogenous material, here, the FGM material has been implemented. It is assumed that the FGM micro-gripper is made of metal and ceramic and that material properties are changed continuously along the beam thickness according to a given function. The nonlinear governing equations of the static and dynamic deflection of microbeams have been derived using the coupled stress theory. The equations have been solved using the Galerkin based step-by-step linearization method (SSLM). The solution procedure has been evaluated against available data of literature showing good agreement. A parametric study has been conducted, focusing on the combined effects of important parameters included DC voltage, temperature variation, geometrical dimensions and ceramic volume concentration on the dynamic response and stability of the FGM micro-gripper.