• Title/Summary/Keyword: Multiple Stress

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Fracture Mechanics Analysis of Multiple Load Path Plate (다중 균열 보강 판재에 관한 파괴 역학적 해석)

  • Han, Moon-Sik;Lee, Yang-Sub
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.10
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    • pp.109-115
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    • 2001
  • The compliance approach to the problem of load sharing between a cracked plate and multiple plate used to bridge the crack. The theory is validated by using calculated stress intensity factors for the multiple load path plate to reduce experimentally observed growth rate to a common base. Calculations are them made on the effect of multiple load path plate width on fatigue crack retardation in order to demonstrate the predictive capability of the technique.

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Finite Element Analysis of Multiple Subsurface Cracks in Half-space Due to Sliding Contact

  • Lee, Sang Yun;Kim, Seock Sam
    • KSTLE International Journal
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    • v.2 no.1
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    • pp.12-16
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    • 2001
  • A finite element analysis of crack propagation in a half-space due to sliding contact was performed. The sliding contact was simulated by a rigid asperity moving across the surface of an elastic half-surface containing single and multiple cracks. Single, coplanar, and parallel cracks were modeled to investigate the interaction effects on the crack growth in contact fatigue. The analysis was based on linear elastic fracture mechanics and the stress intensity factor concept. The crack propagation direction was predicted based on the maximum range of the shear and tensile stress intensity factors.

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Analysis of Multiple Curved Cracks in An Orthotropic Plate (직교이방성 판 내의 다중 곡선균열 해석)

  • Kim, Maan-Won;Park, Jai-Hak
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.6
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    • pp.969-980
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    • 2003
  • The interactions between curved cracks are examined in an orthotropic plate and the effects of rectilinear anisotropy on the stress intensity factors are analyzed. The finite element alternating method (FEAM) is used in this study to get the stress intensity factors for the multiple curved cracks. To obtain analytical solutions, which is necessary in FEAM, the curved cracks are modeled as continuous distributions of dislocations, and integral equations are formulated for unknown dislocation density functions to satisfy the given resultant forces on the crack surfaces. Several basic problems are solved to verify the accuracy and efficiency of the proposed method and it can be found that present results show good agreements with the previously published results.

A Meshless Method and its Adaptivity for Stress Concentration Problems (응력집중문제의 해석을 위한 적응적 무요소절점법에 관한 연구)

  • 이상호;전석기;김효진
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.16-23
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    • 1997
  • The Reproducing Kernel Particle Method (RKPM), one of the popular meshless methods, is developed and applied to stress concentration problems. Since the meshless methods require only a set of particles (or nodes) and the description of boundaries in their formulation, the adaptivity can be implemented with much more ease than finite element method. In addition, due to its intrinsic property of multiresolution, the shape function of RKPM provides us a new criterion for adaptivity. Recently, this multiple scale Reproducing Kernel Particle Method and its adaptive procedure have been formulated for large deformation problems by the authors. They are also under development for damage materials and localization problems. In this paper the multiple scale RKPM for linear elasticity is presented and the adaptive procedure is applied to stress concentration problems. Therefore, this work may be regarded as the edition of linear elasticity in the complete framework of multiple scale RKPM and the associated adaptivity.

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Effects of Academic Stress, Somatization Symptoms, and Social Support on Coping Responses in High School Students (고등학생의 학업 스트레스, 신체화 증상, 사회적 지지가 대처유형에 미치는 영향)

  • Lee, Eun Hee;Kim, Young Im;Geun, Hyo Geun;Lee, Young Shil
    • Journal of the Korean Society of School Health
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    • v.28 no.2
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    • pp.56-66
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    • 2015
  • The purpose of this study was to investigate factors associated with coping responses in Korean public high school students. Methods: This study employed a descriptive survey research design. The sample included 263 high school students who responded to a self-report questionnaire. Variables included socio-demographic characteristics, health-related characteristics, academic stress, somatization symptoms, social support, and coping responses. Data were analyzed using descriptive statistics, t-tests, ANOVA, Pearson's correlations, and multiple regressions. Results: Participants, regarding their school life, reported moderate levels of academic stress ($M{\pm}SD=2.3{\pm}0.52$) and somatization symptoms ($M{\pm}SD=2.3{\pm}0.71$), and a relatively high level of social support ($M{\pm}SD=4.2{\pm}0.67$). All the variables were associated with the use of multiple coping responses. Active-cognitive coping ($M{\pm}SD=2.9{\pm}0.68$) was most frequently used, followed by active-behavioral coping ($M{\pm}SD=2.5{\pm}0.56$). and avoidant coping ($M{\pm}SD=2.3{\pm}0.75$). Significant relationships were found among the measured variables: positive relation between academic stress and somatization symptoms, but, negative between academic stress and both somatization symptoms and social support. Students who had higher stress and more somatization symptoms were more likely to use avoidant coping than the others. In multiple regression analysis, while factors associated with each coping response differed, gender appeared to be a significant factor in all methods. Variables included in the final model explained 27% of the variance in avoidant coping (F=11.40, p<.001). Conclusion: Based on the study results, schools should provide tailored educational programs to help high school students reduce multisource stress and somatization symptoms at school and cope with them in more active and effective ways.

Effect of Self Efficacy and Self Leadership on Stress in Adolescents (청소년의 자기효능감 및 셀프리더십이 스트레스에 미치는 영향)

  • Kim, Nam-Hee;Lee, Hea-Shoon
    • The Journal of the Korea Contents Association
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    • v.15 no.1
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    • pp.211-220
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    • 2015
  • Purpose: The purpose of this study was to identify the effect of self efficacy and self leadership on stress in adolescents. Methods: Data were collected from 722 adolescents and analyzed using descriptive statistics, t-test, ANOVA, Scheffe's test, Pearson correlation coefficients and stepwise multiple regression with the SPSS 20.0 program. Results: Stress differed according to gender, grade, economic level. Self efficacy and self leadership had a significant negative correlation with stress. Stepwise multiple regression analysis showed self efficacy(general self efficacy), self leadership(cognitive strategies), gender(female), grade(high school) explained 32.5% of the total variance in stress. The findings indicate that self efficacy and self leadership had an influence on stress. Conclusions: The results of this study offer basic data for the development of intervention programs to prevent adolescents stress.

The Influence of Collective Self-esteem on Teachers' Job Stress (교사의 집단적 자아존중감이 직무 스트레스에 미치는 영향)

  • CHOI, Tae-jin
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.3
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    • pp.732-745
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    • 2017
  • The purpose of this study was to analyze the influence of collective self-esteem on teachers' job stress. For the study, 223 teachers in elementary school, junior high school, and high school were selected and data on teachers' background variables, collective self-esteem, and job stress were collected. The relationship between variables was analysed by using multiple regression analysis. The results were as follows: The job stress of teacher was significantly different according to teacher's gender, school level, and career experience. When the influence of background variables was controlled and multiple regression analysis was performed, the group self-esteem of teachers had a great influence on mitigating the perception of job stress. Particularly, it was shown that private collective self-esteem and importance to identity are the most important factors in mitigating job stress perception among the sub-variables of collective self-esteem. These results showed that it is an important task for our society to find an effective way to elevate the teacher's collective self-esteem. Teachers' collective self-esteem is expected to play a positive role not only in mitigating job stress but also in enhancing self-fulfillment and personal self-esteem of teacher.

The relationship between preschooler's temperament, father's child-rearing involvement, and mother's child-rearing stress (유아의 기질 및 아버지 양육 참여와 어머니의 양육 스트레스)

  • Lee, Su-Mi;Min, Ha-Yeoung
    • Korean Journal of Human Ecology
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    • v.16 no.2
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    • pp.219-225
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    • 2007
  • The purpose of this study was to clarify how preschooler's adaptive temperament and father's child-rearing involvement may be related to mother's chid-rearing stress. The subjects were 320 mothers whose children were 3, 4 or 5 age preschoolers attending day care centers in Keoungbok. Statistical techniques were Pearson's correlation, hierarchical multiple regression(using SPSS 12.0). The results of this were as follows. 1. Mother's child-rearing stress was negatively related to preschooler's adaptive temperament. 2. Mother's child-rearing stress was negatively related to father's child-rearing involvement. 3. The Multiple Regression analysis showed that preschooler's adaptive temperament and father's child-rearing involvement were significantly predictive to mother's child-rearing stress. And preschooler's adaptive temperament was the stronger predictor of mother's child-rearing stress than father's child-rearing involvement. There was no significant interaction effect of father's child-rearing involvement and preschooler's adaptive temperament on mother's child-rearing stress.

Hardiness : Determinants of Psychological Distress from Stress (스트레스 결과변수의 결정요인으로서의 강인성에 관한 연구 -간호사의 소진(burnout)을 중심으로-)

  • 이미라;소희영;안은경;김태숙
    • Journal of Korean Academy of Nursing
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    • v.28 no.3
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    • pp.583-590
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    • 1998
  • This study was undertaken in order to examine the effect of hardiness on stress-causing factors, defined in this study as burnout in nursing. The subjects were 248 nurses working in three general hospitals in Taejon. The instruments used for this study were a survey of general characteristics, modified Health-Related Hardiness Scale(HRHS) (25 items), job stress scale (63 items), and burnout scale (20 items). Analysis of data was done through the mean, percentage, Pearson correlation coefficient, and stepwise multiple regression done with a SAS program. The results of this study are as follows. 1) The average item score for the job stress was high at 4.44. In the subcategories, the highest degree of stress was night duty(5.11), and work overload(4.70), responsibility for extra affairs(4.70), conflict in nurse-doctor relationships(4.69), and low reward(4.63) in that order. 2) In the stepwise multiple regression analysis, hardiness(11.55%) was a significant determinant of burnout along with job stress(17.24%) and job duration(12.94%). The results of this study show that hardiness has an effect on psychological distress caused by stress.

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The Study on the Effect of the Maternal Parenting Stress on the Children Depression (아동의 우울에 영향을 미치는 어머니 관련변인에 관한 연구)

  • Woo, Hee Jung;Choi, Jung Mi
    • Korean Journal of Child Studies
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    • v.25 no.4
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    • pp.191-200
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    • 2004
  • The purpose of this research is to delineate the effect of maternal variables of the children's depression. Such variables as the mother's age, her education level and maternal parenting stress have been chosen for the analysis. The sample subject were 659 pairs of fifth/sixth grade of elementary school and first/second grade of middle school and their mothers. The data were analyzed frequency, percentage, factor analysis, Cronbach's alpha, ANOVA, Pearson's correlation, and stepwise multiple regression analysis. The major findings of the research are as follows : First, the children's depression is significantly related to mother's education level but the children's depression is not significantly related to mother's age. Second, parenting stress related to temperament, relationship and learning expectation is significantly related to children's depression. Third, the result of step multiple regression analysis on the effects of the maternal variables to the children's depression indicates that maternal parenting stress related to temperament, relationship and mother education level are the significant contributing factor. All in all, the maternal variables account for 7% of the children's depression score.

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