• Nuclear Engineering and Technology
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• 제42권6호
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• pp.680-689
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• 2010

The crack-tip stress fields and fracture mechanics assessment parameters for a surface crack, such as the elastic stress intensity factor or the elastic-plastic J-integral, can be affected significantly by the adjacent cracks. Such a crack interaction effect due to multiple cracks can alter the fracture mechanics assessment parameters significantly. There are many factors to be considered, for instance the relative distance between adjacent cracks, the crack shape, and the loading condition, to quantify the crack interaction effect on the fracture mechanics assessment parameters. Thus, the current assessment codes on crack interaction effects (crack combination rules), including ASME Sec. XI, BS7910, British Energy R6 and API 579-1/ASME FFS-1, provide different rules for combining multiple surface cracks into a single surface crack. The present paper investigates crack interaction effects by evaluating the elastic stress intensity factor and the elastic-plastic J-integral of adjacent in-plane surface cracks in a plate through detailed 3-dimensional elastic and elastic-plastic finite element analyses. The effects on the fracture mechanics assessment parameters of the geometric parameters, the relative distance between two cracks, and the crack shape are investigated systematically. As for the loading condition, an axial tension is considered. Based on the finite element results, the acceptability of the crack combination rules provided in the existing guidance was investigated, and the relevant recommendations on a crack interaction for in-plane surface cracks are discussed. The present results can be used to develop more concrete guidance on crack interaction effects for crack shape characterization to evaluate the integrity of defective components.

• 한국정밀공학회지
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• 제18권1호
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• pp.201-212
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• 2001

If defects are located far apart, fatigue cracks are independently initiated from them and gradually approach other cracks so that the fatigue life becomes influenced by the crack growth behavior of those interacting cracks. In this study, the effect of the stress interaction between defects on the fatigue crack propagation behavior is investigated experimentally and these results are verified by finite element method. In addition, fatigue crack propagation behaviors under micro hole interaction field are studied.

• 한국보육지원학회지
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• 제13권1호
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• pp.107-124
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• 2017

Objectives: The purpose of this study was to investigate the effects of children's pride and shame on their interactive peer play, mediated by their daily stress. Methods: The participants of this study were 172 five-year-old children (80 boys and 92 girls) attending kindergartens or child-care centers in Chungbuk, Korea. The data were analyzed by descriptive and correlational analyses, and structural equation modeling using SPSS 19.0 and AMOS 21.0. Results: Children's shame had a significant indirect effect on their interactive peer play, including play-disruption, play-disconnection and play-interactions, mediated by daily stress; children's shame had a significant direct effect on play interaction. However, children's pride did not have a direct effect on daily stress and an indirect effect on their interactive peer play. In other words, high levels of shame among children led to high perceived daily stress. In turn, perceived daily stress increased play-disconnection and play-disruption, while it decreased play-interactions. Meanwhile children's shame led to a low level of play-interaction among young children. Conclusion/Implications: The results imply that children's perceived shame would influence their behaviors in social contexts as well as their psychological wellbeing such as the level of daily stress.

• 대한기계학회논문집A
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• 제21권7호
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• pp.1097-1105
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• 1997

Because of the existence of stress interaction field made by other defects and propagating cracks, the structure may be weakened. Therefore in this study, the crack behavior in the interaction field made by two different cracks is studied experimentally. In the experiment, vertical distance between two cracks and applied stress are varied to make different stress interacted field. In addition, the effect of plastic zone is used to examine crack propagation path and rate. Three types of crack propagation in the interacted field were found, and crack propagating path and rate of two cracks were significantly changed according to different applied stress as each crack propagates. And the results are attributed to the effect of the size and shape of the plastic zone.

• 한국가족관계학회지
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• 제21권1호
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• pp.51-76
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• 2016

Objectives: This study aims to investigate the effect of marital relationship on parenting stress among dual- and single-earner families. In particular, this study focuses on the interaction effect of marital relationship and father's child-rearing involvement on the parenting stress. To access factors associated with parenting stress, we included marital satisfaction and marital conflict as the dimensions of marital relationship in this study. Method: We employed data from the 5th wave of the Panel Study of Korean Children(PSKC) data. Our analysis sample consisted of 1,515 parents having at least one child aged under 4 years. Also, this study conducted descriptive statistics and multiple regression analysis. Results: First of all, marital satisfaction and marital conflict were significantly related to parenting stress for both mother and father in dual-earner families. While both indicators were significantly related to parenting stress for father, marital conflict only was a significant predictor for mother in single-earner families. Second, father involvement was a significant predictor for parenting stress for father in both dual- and single-earner families. Third, interaction effects were found between father involvement and marital conflict in the dual-earner families and between father involvement and marital satisfaction in the single-earner families. Conclusions: Based on the results, we recommended programs designed to enhance father's child-rearing involvement such as parenting education and community-based campaign. In addition, we recommended that policy and practice need to identify marital relationship dynamics to promote father's involvement and to reduce marital conflict in both dual- and single-earner families accordingly.

• Geomechanics and Engineering
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• 제21권6호
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• pp.571-582
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• 2020

Aiming at the mechanical and structural characteristics of the contact zone composite rock, the uniaxial compression tests and numerical studies were carried out. The interaction forms and formation mechanisms at the contact interfaces of different materials were analyzed to reveal the effect of interaction on the mechanical behavior of composite samples. The research demonstrated that there are three types of interactions between the two materials at the contact interface: constraint parallel to the interface, squeezing perpendicular to the interface, and shear stress on the interface. The interaction is mainly affected by the differences in Poisson's ratio and elastic modulus of the two materials, stronger interface adhesion, and larger interface inclination. The interaction weakens the strength and stiffness of the composite sample, and the magnitude of weakening is positively correlated with the degree of difference in the mechanical properties of the materials. The tensile-shear stress derived from the interaction results in the axial tensile fracture perpendicular to the interface and the interfacial shear facture. Tensile cracks in stronger material will propagation into the weaker material through the bonded interface. The larger inclination angle of the interface enhances the effect of composite tensile/shear failure on the overall sample.

• 디지털융복합연구
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• 제17권12호
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• pp.13-22
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• 2019

본 연구는 경력단절여성의 자녀상호작용, 부부갈등, 사회적 지지가 양육스트레스에 미치는 영향을 살펴보고, 자녀상호작용과 양육스트레스 관계에서 부부갈등의 매개효과를 확인하는 것을 목적으로 하였다. 이를 위해 8차년도 한국아동패널 데이터를 활용하였으며, 868명의 경력단절여성의 데이터를 대상으로 기술통계, 상관분석, 중다회귀분석을 실시하였다. 분석결과, 경력단절여성의 양육스트레스에 영향을 미치는 요인으로는 자녀상호작용(β=-.184), 부부갈등(β=.427), 사회적지지(β=-.096)이며 32.3%의 설명력을 보였고, 부부갈등의 영향력이 가장 높았다. 또한 자녀상호작용과 양육스트레스의 관계에서 부부갈등은 부분매개를 하는 것으로 나타났다. 이를 바탕으로 본 연구는 일·가정양립 시대에 경력단절여성의 노동시장 재진입을 지원하는 관점에서 이들의 양육스트레스를 예방·경감하기 위한 정책적, 실천적 방안을 제언하였다.

• 한국해양공학회지
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• 제15권3호
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• pp.58-62
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• 2001

The objective of research is to clarify the interaction between dislocations and precipitates during high temperature creep deformation behaviors of high n austenitic steels. After measuring the internal stress in minimum creep rate state under applied stress of 236MPa at 873K, a transmission electron microscope (TEM) observation was performed to investigate the interaction between dislocations and precipitates during high temperature creep deformation. The band widths and values of internal stress increased when the nitride precipitates distribute more densely. Fine nitrides disturbed the dislocation movement with pinning the dislocations and perfect dislocations were separated into Shockley partial dislocations by fine nitrides. Coarse nitrides disturbed the dislocation movement with climb mechanism.

• 대한가정학회지
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• 제50권3호
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• pp.51-58
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• 2012

This study investigated the relationship between infants' temperament and mothers' parenting stress. This investigation is done by focusing on the interaction effects between the infants' temperament and maternal factors. A total of 1,120 infants and their mothers from a national sample were selected as subjects for carrying this investigation. The EAS (Emotionality, Activity and Sociality) Temperament Survey for Children: Parental Ratings was used to measure the infants' emotionality temperament, and PSI-SF(Parenting Stress Index-Short Form), KMSS(Kansas Marital Satisfaction Scale) and a survey on socio-demographic variables were used for the maternal factors. Two-way ANOVA revealed that the parenting stress was significantly different according to the infants'emotionality temperament. Most importantly, there were significant interaction effects between the infants' emotionality temperament and maternal factors(education level, employment status and marital satisfaction). The results were discussed in terms of the goodness of fit of the temperament and parenting models.

• 여성건강간호학회지
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• 제9권3호
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• pp.224-234
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• 2003

Purpose: This study was to test the effects of a full body massage on labor pain and delivery stress reaction for primipara during labor. Method: This study employed a quasi- experimental method(nonequivalent control group, pre-post test design). The subjects of this study were 57 primipara hospitalized at the U OB & GYN hospital in Inchon from November 1. 2001 to July 31, 2002. 28 women were assigned to the experimental group and 29 to the control group. The experimental group was given 20 minutes full body massage for each of three delivery phases. The control group was given conventional delivery care. The levels of labor pain were measured by the Visual Analogue Scale and the expression scores of the labor pain and the levels of delivery stress reaction were measured by pulse rate, respiration rate, and blood pressure, and State-Anxiety Scale. Data were analyzed using the repeated measures analysis of covariance(ANCOVA), t-test, $X^2$- test, simple ANCOVA with SPSS program. Result: There was no interaction effect between time and group(F=.370, p=.693), but significant time effects were found for subjective labor pain(F=3.840, p=.028). There was no interaction effect between time and group(F=.112, p=.894), but significant group effects were found for objective labor pain(F=12.299, p=.001). There was no interaction effect between time and group for PR(F=.172, p=.843), RR(F=.626, p=.539), SBP(F=.089, p=.915), DBP(F=.748, p=.479), but significant group effects were found for SBP(F=7.547, p=.008). The level of status anxiety of the experimental group was significantly lower than the control group(F=11.787, p=.001). Conclusion: This study showed that the full body massage has partially positive effect on labor pain and delivery stress reaction. Therefore this study suggested that the full body massage might be used clinically to help primipara during labor.