• Title/Summary/Keyword: Variable stress

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The relationships between Middle-Aged Men's Family and Work related variables and satisfaction (중년기 남성의 가족 및 직업관련 변인과 생활만족도의 관계)

  • Lee, Eun-A
    • Korean Journal of Human Ecology
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    • v.16 no.3
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    • pp.547-562
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    • 2007
  • The purpose of this study was to investigate the relationships of middle-aged men's family and work related variables and satisfaction. Based on the results of the study, the following was concluded ; First, there were significant differences in men's satisfaction across education level, economic variables, and occupation. Second, family related variables, work related variables, and work-family conflict were significantly correlated with satisfaction. In reference to family related variable, satisfaction was higher when marital satisfaction is good, parental stress, adult caring burden, and work-family conflict are lower. In reference to work related variables, satisfaction is higher when job stress is lower, job security is lower, and colleague relationship is good. Third, family related variables, work related variables, and work-family conflict were significantly correlated with mutually one another. Specifically, parental stress is correlated with work related variables. A higher correction was reported between work-family conflict and job stress. Finally, results of multiple regression analysis showed that these variable influenced middle-aged men's satisfaction. Moreover, the degree of explanation for satisfaction increased more, when family and work related variables, and work-family conflict add in individual character variables.

Systematic Review of Quantitative Research related to Maternal Adaptation among Women Immigrants by Marriage in Korea (한국사회 결혼이민여성의 모성적응 관련 양적논문에 대한 체계적 고찰)

  • Song, Ju-Eun;Roh, Eun Ha;Park, So Mi
    • Women's Health Nursing
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    • v.21 no.1
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    • pp.55-70
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    • 2015
  • Purpose: This study aimed to describe knowledge status of current research related to maternal adaptation of women immigrants by marriage in Korea. Methods: Eighteen quantitative current researches published from January, 2006 to August, 2014 that met the inclusion and exclusion criteria. These 18 articles finally selected for systemic review from 5,168 articles. All current researches included the mother within one year after childbirth and one variable related to maternal adaptation at least. Results: Variables related to psychological adaptation (48.1%) were mostly studied. In detail, parenting stress (17.3%) and parenting competency (15.4%) were frequently surveyed. Also, social support (7.7%), husband rearing support (5.8%) of relational adaptation, and acculturation (3.8%) of cultural adaptation were importantly studied. In addition, frequently used instruments for each study variable were analyzed and evaluated. As major results, parenting stress and parenting efficacy were significantly influenced by social support or husband rearing support and acculturation, and had an effect on parenting behaviors. Various maternal education programs were effective in improving maternal role confidence or parenting efficacy and decreasing parenting stress. Conclusion: Nursing intervention programs for improving maternal adaptation should focus on decreasing parenting stress and increasing parenting efficacy by improving social support and acculturation level of women immigrants by marriage in Korea.

Strain energy-based fatigue life prediction under variable amplitude loadings

  • Zhu, Shun-Peng;Yue, Peng;Correia, Jose;Blason, Sergio;De Jesus, Abilio;Wang, Qingyuan
    • Structural Engineering and Mechanics
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    • v.66 no.2
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    • pp.151-160
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    • 2018
  • With the aim to evaluate the fatigue damage accumulation and predict the residual life of engineering components under variable amplitude loadings, this paper proposed a new strain energy-based damage accumulation model by considering both effects of mean stress and load interaction on fatigue life in a low cycle fatigue (LCF) regime. Moreover, an integrated procedure is elaborated for facilitating its application based on S-N curve and loading conditions. Eight experimental datasets of aluminum alloys and steels are utilized for model validation and comparison. Through comparing experimental results with model predictions by the proposed, Miner's rule, damaged stress model (DSM) and damaged energy model (DEM), results show that the proposed one provides more accurate predictions than others, which can be extended for further application under multi-level stress loadings.

The Curved Interfacial Crack Analysis between Foam and Composite Materials under Anti-plane Shear Force (반평면 전단하중력하에서 곡면형상 접합면을 가지는 폼과 복합재료 접합부의 계면크랙에 관한 연구)

  • 박상현;전흥재
    • Composites Research
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    • v.13 no.4
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    • pp.67-74
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    • 2000
  • The general solution of the anti-plane shear problem for the curved interfacial crack between viscoelastic foam and composites was investigated with the complex variable displacement function. Kelvin-Maxwell three parameter model is used to present viscoelasticity and the Laplace transform was applied to treat the viscoelastic characteristics of foam in the analysis. The stress intensity factor near the interfacial crack tip was predicted by considering both anisotropic and viscoelastic properties of two different materials. The results showed that the stress intensity factor increased with increasing the curvature of the curved interfacial crack and it also increased and eventually converged to a specific value with increasing time. The stress intensity factor increased with increasing the ratio of stiffness coefficients between foam and composites and the effect of fiber orientation on the stress intensity factor decreased with increasing the ratio of stiffness coefficients between foam and composites.

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Fatigue Life Prediction of Welded Structural Material under Variable Loading (변동하중(變動荷重)을 받는 용접구조재(熔接構造材)의 피로수명(疲勞壽命) 예측(豫測))

  • Kim, Min-Gun;Kim, Dong-Yul
    • Journal of Industrial Technology
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    • v.18
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    • pp.187-193
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    • 1998
  • In this study, about the fatigue life of welded structure material under fluctuation loading, the prediction life which is produced by using the Histogram Recorder System was compared with the experimental life which is produced by the RMC model which is imported by conception of equivalent stress. In this result, this is represented few difference by comparing prediction life which is produced by damage analysis depended on Miner's rule, by using the Histogram Recorder System, with experimental life which is produced by the RMC load model which is imported by conception of equivalent of stress, therefore fatigue life is easily predicted by using Histogram Recorder System, and result of prediction has equivalent accuracy with other method which is more complex than the Histogram Recorder System. Besides the damage which is produced by stress which is high thirty percentage rank in the stress range of damage inducing, is nearly equal to the damage which is induced the rest of seventy percentage, there fore we can see that damage accumulation which is induced few time overload which is effected welded structure material is great.

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A stress field approach for the shear capacity of RC beams with stirrups

  • Domenico, Dario De;Ricciardi, Giuseppe
    • Structural Engineering and Mechanics
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    • v.73 no.5
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    • pp.515-527
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    • 2020
  • This paper presents a stress field approach for the shear capacity of stirrup-reinforced concrete beams that explicitly incorporates the contribution of principal tensile stresses in concrete. This formulation represents an extension of the variable strut inclination method adopted in the Eurocode 2. In this model, the stress fields in web concrete consist of principal compressive stresses inclined at an angle θ combined with principal tensile stresses oriented along a direction orthogonal to the former (the latter being typically neglected in other formulations). Three different failure mechanisms are identified, from which the strut inclination angle and the corresponding shear strength are determined through equilibrium principles and the static theorem of limit analysis, similar to the EC-2 approach. It is demonstrated that incorporating the contribution of principal tensile stresses of concrete slightly increases the ultimate inclination angle of the compression struts as well as the shear capacity of reinforced concrete beams. The proposed stress field approach improves the prediction of the shear strength in comparison with the Eurocode 2 model, in terms of both accuracy (mean) and precision (CoV), as demonstrated by a broad comparison with more than 200 published experimental results from the literature.

Optimal Dimension Design and Stability Analysis of Non-slip Steel Grating (금속 그레이팅의 높이변화에 따른 최적치수 설계 및 안정성 해석)

  • Son, In-Soo
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.3
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    • pp.357-363
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    • 2022
  • In this study, in order to develop an non-slip metal grating, the stability of the grating according to the span of the grating and the gap and height of the bearing bar was evaluated. The optimal shape design of the grating was performed using the results of determining the stability of the grating. The purpose of this study is to determine the stability according to the spacing and height of the bearing bar by applying the design pressure at the design stage to develop the anti-skid grating, and to design the optimal shape for cost reduction. In the optimal design, the target variable was set as the mass, and the optimal design of the grating was performed based on about 20%. Regardless of the height of the bearing bar of the grating, the stress and deformation of the span and the grating showed a proportional tendency to each other, and it was found that the stress decreased as the height of the bearing bar increased. Based on the structural analysis results, an optimal design was performed using mass as the objective variable, and the existing 2mm thickness was changed to 1.6mm, reducing the mass by about 19%. The stress increased by about 4.4% compared to the maximum stress of the existing grating, but the minimum safety factor was 3.1, indicating that the optimally designed grating was stable.

Relationships between Child′s Self-Regulation and Stress (아동의 자아통제능력과 스트레스와의 관계)

  • 정현희;최경순
    • Journal of the Korean Home Economics Association
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    • v.39 no.9
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    • pp.175-188
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    • 2001
  • The purpose of this study was to examine the relationships between child's self-regulation and stress according to child's sex. The subjects for this study were 380 children of 5-6th grade selected from elementary schools in Busan. Lee, Soon-Kyu's questionnaires(1994) on child's self-regulation and Han, Mi-Hyun's questionnaires(1996) on child's stress were used. Statistical techniques such as Manova, Pearson's correlation, multiple regression, canonical were used. The resets were as follows : (1) According to sex, there were significant differences in child's self-regulation and stress. The girls showed more self-regulation and higher friend-related stress than the boys. The boys showed higher parent-related stress than the girls. (2) Relationships between child's self-regulation and stress showed as follows : The boys who used more impulsive-control perceived lower friend-related stress, lower school-related stress, lower teacher-related stress, and lower surroundings-related stress. And the boys who used more behavioral-control perceived lower school-related stress, lower teacher-related stress, and lower surroundings-related stress. (3) The predicted variable for boy's friend-related stress was impulsive-control. The predicted variables for boy's school-related stress, teacher-related stress and surroundings-related stress were impulsive-control and behavioral-control. (4) Among three dimensions of self-regulation for boy, the effective variables were impulsive-control and behavioral-control. And among six dimensions of stress were surroundings-related stress, school-related stress and friend-related stress. Implications of this study were discussed in terms of child's self-regulation and stress.

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The Study of the Effect of Self-Differentiation Degree on Stress Level and Stress Coping Strategies in College Students (대학생의 자아분화 정도가 스트레스 수준 및 대처방식에 미치는 영향에 관한 연구)

  • Bae, Ok-Hyun;Hong, Sang-Ook
    • Korean Journal of Human Ecology
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    • v.17 no.1
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    • pp.27-34
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    • 2008
  • The purpose of this study is to study how college students cope with their stress and how the level of their self-differentiation affects degrees of stress and stress-coping strategies. The questionnaires were handed to 497 college students at Y university in Gyeongbuk Province and the data were analyzed in terms of Cronbach's ${\alpha}$-coefficient, frequency and percentage, t-test, and regression analysis by using the SPSS statistical package. The results of this study were as follows: 1. For stress level, degree of self-differentiation and stress coping strategies of the college students, the average scores were 3.56, 2.53 and 3.49, respectively in 5-point Likert Scale, indicating that the students possess the above-average score for the degree of self-differentiation and stress-coping strategies and the below-average score for stress levels. 2. From examination of difference verification of stress levels based on the degree of self-differentiation and effect of degree of self-differentiation on stress levels, it was found that the higher is the degree of self-differentiation the lower is the stress level. 3. From examination of difference verification of stress-coping strategies according to the degree of self-differentiation and effect of degree of self-differentiation levels on stress coping strategies, we found that the students of higher degree of self-differentiation exercise the more active stress coping strategies. These results show that the degree of students' self-differentiation is a significant variable that influences their stress levels and stress control methods. It is thought that students' self-differentiation functions to minimize their stress and to actively cope with their stressful situation and that a high degree of self-differentiation is a significant mediator variable that is beneficial to students' mental health. It follows from the above observations that while college students in this study seem to possess good degrees of self-differentiation and stress coping capabilities and low stress levels they need to seek for the ways to improve their degree of self-differentiation by seeing into themselves and relationships with others around them. Parents, schools and consultation agencies are required to take an active hand to educate and encourage them to cope with their stress positively.

An Exploratory Structural Analysis of the Accident Causing Factors in Railway Traffic Controllers (철도관제사의 사고유발 요인에 관한 탐색적 구조분석)

  • Kim, Kyung-Nam;Shin, Tack-Hyun
    • Journal of the Korea Society for Simulation
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    • v.27 no.1
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    • pp.119-126
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    • 2018
  • This study intended to exploratively testify human error causing factors for railway traffic controller, using AMOS structural equation model. Through literature survey, fatigue and stress as exogenous variable, errors in information process such as cognitive, memory, storage, and execution error as endogenous variable, and accident and incident(near-miss) as dependent variable were set up. Results based on AMOS using 201 railway traffic controllers' questionnaire showed that a clear causality loop like as 'stress ${\rightarrow}$ memory error ${\rightarrow}$ storage error ${\rightarrow}$ incident(near-miss) ${\rightarrow}$ accident' is formed. This result suggests that for the purpose of mitigation of traffic controller's accident, it is so necessary to reduce memory and execution error in the information processing process based on the effective management of stress, as the precedent of them.