• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.205-213
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• 2014

A wind generator (WG) maximum power point tracking (MPPT) system is presented here. It comprises of a variable-speed wind generator, a high-efficiency boost-type dc/dc converter and a control unit. The advantages of the aimed system are that it does not call for the knowledge of the wind speed or the optimal power characteristics and that it operates at a variable speed, thus providing high efficiency. The WG operates at variable speed and thus suffers lower stress on the shafts and gears compared to constant-speed systems. It results in a better exploitation of the available wind energy, especially in the low wind-speed range of 2.5-4.5 m/s. It does not depend on the WG wind and rotor-speed ratings or the dc/dc converter power rating. Higher reliability, lower complexity and cost, and less mechanical stress of the WG. It can be applied to battery-charging applications.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.201-208
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• 1991

In case that an interface crack exists in an infinite two-dimensional elastic bimaterial, the crack surface is insulated under traction free and the uniform heat flow vertical to the crack from infinite boundary is given. Temperature and stress potentials are obtained by using complex variable approach to solve Hilbert problems. The results are used to obtain thermal stress intensity factors. Only mode I thermal stress intensity factor occurs in case of the homogeneous material. Otherwise, mode I and II thermal stress intensity factor is much smaller than one of mode II.

• Journal of the Korean Home Economics Association
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• v.41 no.3
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• pp.31-44
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• 2003

The purpose of this study is to investigate the difference of maternal parenting stress through early childhood between urban(Seoul and Incheon) and rural area(Iksan and Kimpo). The subjects were 286 unemployed mothers who have less than 5-year-old children. The statistics used for this data were frequency, percentile, t-test, ANOVA, and multiple regression. The finding from the present study certainly suggested that mother's level of self-differentiation, marital satisfaction, father's parenting support turned out to a significant variables on maternal parenting stress. Results of the regression analysis that the etiologic model of this study was more proper to urban than rural area, and father's parenting support is the most effective variable in predicting maternal parenting stress in both area. Implications based on this study are as follows ; parenting education programs to encourage for father's parenting support with be developed, and various empirical studies about maternal parenting stress in with area will be needed.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.1
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• pp.66-80
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• 2001

Most people experience stress during his or her life. The types of psychosocial stressors are variable. Also, the stress appraisal, coping, and responses in stress process are variable. These varieties reflect individual differences due to ongoing social situation, personal dispositions such as personal resources and vulnerability factors, etc. The stress process results in psychosocial growth or no substantial change in functioning or health, or adverse change in functioning(illness) or health to person. Therefore, the preventive management and treatment of stress need to be tailored to individual characteristics. All physicians managing the stress-related patients have to understand the multidimensional aspects of stress. To understand stress better in psychosocial aspect, I comprehensively reviewed the literature on stress.

• Steel and Composite Structures
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• v.36 no.6
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• pp.617-629
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• 2020

The purpose of this paper is to depict the effect of rotation and initial stress on a magneto-thermoelastic medium with diffusion. The problem discussed within memory-dependent derivative in the context of the three-phase-lag model (3PHL), Green-Naghdi theory of type III (G-N III) and Lord and Shulman theory (L-S). Analytical expressions of the considered variables are obtained by using Laplace-Fourier transforms technique. Numerical results for the field quantities given in the physical domain and illustrated graphically in the absence and presence of a magnetic field, initial stress as well as the rotation. The differences in variable thermal conductivity are also presented at different parameter of thermal conductivity. The numerical results of the field variables are presented graphically to discuss the effect of various parameters of interest. Some special cases are also deduced from the present investigation.

• Structural Engineering and Mechanics
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• v.77 no.2
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• pp.245-259
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• 2021

In this research, the influence of the laminate stacking sequence on thermal stress distribution in symmetric composite plates with a quasi-square cutout subjected to uniform heat flux is examined analytically using the complex variable technique. The analytical solution is obtained based on the thermo-elastic theory and the Lekhnitskii's method. Furthermore, by employing a suitable mapping function, the solution of symmetric laminates containing a circular cutout is extended to the quasi-square cutout. The effect of important parameters including the stacking sequence of laminates, the angular position, the bluntness, the aspect ratio of cutout, the flux angle and the composite material are examined on the thermal stress distribution. It is found out that the circular shape for cutout may not necessarily be the optimum geometry for all stacking sequences. The finite element analysis results are used to validate the analytical solution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8157-8164
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• 2015

The purpose of this study is to find out how a parents' mental characteristics with preschool children(self-esteem, self-efficacy, depression) has effect on a mother's parenting stress by the medium of a father's parenting stress. The fourth year data of The Korean Children Panel of the KICCE(2011) was used, and the collected data was fathers and mothers with 1,754 children who are more than 35 months but not more than 42 months. For data analysis, analysis of frequency and correlation analysis were carried out using SPSS 18.0, and they were analysed with Structural Model to observe the relationship of each variable and influence, and it was found that the goodness of fit of the model was outstanding. As a result, the psychological traits of fathers impact directly on mothers' parenting stress. Mothers' psychological features increased mothers' parenting stress by a medium of fathers' parenting stress. The study showed that fathers' parenting stress that is a mediator variable performed a role as a mediator variable.

• Child Health Nursing Research
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• v.17 no.2
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• pp.127-135
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• 2011

Purpose: The purpose of this study was to examine the relationship of mothers' recognition of Attention deficit hyperactivity disorder (ADHD), parenting stress and family support in mothers of children diagnosed with ADHD. Methods: The data were collected from December 24, 2009 to July 23, 2010. The participants were 141 mothers of children diagnosed with ADHD and who lived in D city. Descriptive statistics, t-test, ANOVA, Pearson correlation coefficients with SPSS 17.0 were used to analyze the data. To determine the most effective variable (mothers' recognition, parenting stress and family support) to predict parental stress, data were analyzed using canonical correlation with SAS 9.1 TS. Results: Canonical correlation analysis revealed that professional and teachers' roles of the 3 sub-domains of mothers' recognition were the most outstanding variables in predicting parenting stress. Parental distress/parent-child dysfunctional interaction of parenting stress was the most outstanding variable in predicting both mothers' recognition and family support. Spouse cooperation in family support was the most outstanding variable in predicting parenting stress. Conclusion: The results suggest that strengthening parents' recognition of ADHD and supporting interventions are important for reducing parenting stress. Professional and teachers' roles, parental distress/parent-child dysfunctional interaction and spouse cooperation should be included in the contents of structured programs.

• Journal of Korean society of Dental Hygiene
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• v.3 no.1
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• pp.45-57
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• 2003

The purpose of this study is to identify the factors affecting job stress and relationship between dental hygienists personal characteristics and them. Final purpose of this study provides the basic data of dental hygienists interventions to help dental hygienists' job stress reduction program. Data were drawn from a convenient sample of 401 dental hygienists who were working for dental clinic, general hospitals, and university hospitals in Seoul and Kyungi areas. The results were analyzed with spsswin 10.0 and the conclusion is as follow: 1. General special quality distribution of dental hygienist is 25-59 and respondent who work in the dentist's office by maiden less than was most. 2. The dental hygienists' job stress was 2.68, it indicates considerably high compare to normal another groups. 3. 'By work, feel fatigue' appeared highest by 3.60 in 5 points full marks from item of business amount connection stress. 4. Only business amount connection stress was expose that is significant in relation with job stress and individual character type. 5. Age, dependent's number, faith, character type variable appeared to keep in mind for connection factor which influence in job stress. 6. Job stress connection factor by character type was expose by variable savages significant thing 'that do work year all as dental hygienist' in A type.

• Journal of Families and Better Life
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• v.17 no.3
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• pp.63-82
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• 1999

This study has a purpose to provide with the basis reference to decrease the housewives' stress and to improve the quality of family life by investigating the difference in the level of the stress resulted from home management according to background variables family cohesion and adaptability and by finding out relative importance of the variables which affect the stress of housewives resulted from home management. For all above the 550 self-reported questionnaires were distributed to housewives who have at least one child with their spouse in seoul. Finally 433 data were used for the final analysis. The major findings of this study are summarized as follows: First Family cohesion and adaptability show a significant difference by the housewives' education level the number of children communication satisfaction. Second housewives' stress is different significantly in accordance with the state of employment and communication satisfaction. Third it showed the lower the family coh sion and adaptability are the higher the housewives' stress is. And more influential variable of the two on home management stress is family cohesion. Fourth The background variables that influence in home management stress were education level perceived life level and age. Last As a result of looking into relative influence of the variables on the housewives' stress both psychological variable(perceived life level) and family cohesion were important variables in explaining housewives' home management stress.