• 대한기계학회논문집
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• 제17권2호
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• pp.313-330
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• 1993

The propagating crack problems under dynamic plane mode in orthotropic material is studied in this paper. To analyze the dynamic fracture problems in orthortropic material, it is important to know the dynamic stress components and dynamic displacement components around the crack tip. Therefore the dynamic stress components of dynamic stress field and dynamic displacement components of dynamic displacement field in the crack tip of orthotropic material under the dynamic load and the steady state in crack propagation were derived. When the crack propagation speed approachs to zero, the dynamic stress component and dynamic displacement components derived in this study are identical to the those of static state. In addition, the relationships between dynamic stress intensity factor and dynamic energy release rate are determinded by using the concept of crack closure closure energy with the dynamic stresses and represented according to physical properties of the orthotrophic material and crack speeds. The faster the crack velocity, the greater the stress value of stress components in crack tip. The stress value of the stress component of crack tip is greater when fiber direction coincides with the crack propagation than when fider direction is normal to the crack propagation.

• 가정∙방문간호학회지
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• 제19권2호
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• pp.195-203
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• 2012

Purpose: This study is conducted to investigate the stress level, stress source and stress coping of nursing students in college. Methods: This study was a cross sectional survey and the data was collected from 341 nursing students by means of self-reported questionnaires from April 2 to May 31, 2012. Collected data were analyzed on SPSS win 18.0. Results: The nursing students experienced moderate levels of stress. The source of stress for students came from 'one's own self'. The most common stress coping used by students was 'make a wish'. There were significant differences in the source of stress and the stress coping according to the nursing students' year of school and other general characteristics, such as motivation of entrance and satisfaction in school life. Conclusion: These results suggest that it is important to develop stress management program and strategies based on nursing students' individual characteristics and sources of stress.

• 한국직업건강간호학회지
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• 제25권4호
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• pp.311-319
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• 2016

Purpose: This study examined association of job stress with health-promoting behaviors and objective health status in 129 clinical nurses working at a university hospital. Methods: A cross-sectional and descriptive design was used. Job stress and health behaviors were measured with Korean Occupational Stress Scale and Heath Promoting Lifestyle Profile-II, respectively. Health status measured with afternoon plasma cortisol, C-peptide, and lipid profiles. Results: The level of job stress among clinical nurses was moderate with 51.41 on average. The mean for health-promoting behavior in the low stress group was significantly higher than that in the high or moderate stress groups (p<.001). The proportions of nurses with high C-peptide and cortisol levels, or low high-density lipoprotein levels, ranged from 14.0% to 35.7%. In particular, the percentage of nurses with high C-peptide levels was significantly higher in moderate and high stress groups than in the low stress group (24.1% versus 11.6%, p<.05). Conclusion: The study findings affirmed the associations of job stress with health-promoting behaviors as well as selected health status indicators such as C-peptide in clinical nurses. Job stress management intervention can help clinical nurses to improve their health-promoting behaviors and health status.

• Journal of Welding and Joining
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• 제32권1호
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• pp.61-65
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• 2014

The purpose of this study is to evaluate the applicability of the element stress to establish S-N design curve for the welded lap joint with thin plates below 2mm thickness. In order to do it, the extensive fatigue tests of the welded lap joints with INVAR alloy were performed. With the results, the deign S-N curves for the lap-weld were established by using the reference stresses such as the nominal stress range at the weld throat area, hot spot stress range and element stress range, and compared with regard to the standard deviation. The standard deviation of S-N curves with element stress range was less than that of S-N curves with other reference stresses. In addition, FEA results show the amount of the element stress is less sensitive to mesh size. Based on the results, it can be concluded that the element stress is to be used as the reference stress for the design S-N curves of the welded lap joint.

• 한국가정과교육학회지
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• 제8권1호
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• pp.59-78
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• 1996

The purpose of this study were to investigate adolescents’level of stress, and coping behavior of stress as related to socio-demographic variables. The subjects were 270 first-grade middle school students and 258 first-grade high school students in Ansan. The data were analyzed by S.A.S. Program Package, the statistical methods of Frequency, Percentage, Mean, Standard deviation, T-test, One-way Anova, DMR(Duncan’s Multiple Range Test) The results of this study were as followed：1) The general tendency of adolescents’level of stress, and coping behavior of stress were that high school students experienced more stress than middle school students and both experienced more stress in school life than in family life. 2) According to personal variable, there were differences in the grade and scholarly attainment in the low-level stress group. According to parents variables, the level of stress differed significantly according to mother’s school career and father’s occupation in the low-level-stress group. There was significant difference in accordance with mother’s occupation in the high-level-stress group. 3) The coping behavior of stress according to adolescent variables differed significantly according to grades, the monthly income of the household, mother’s level of education and the father’s occupation.

• 대한조선학회논문집
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• 제42권2호
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• pp.129-135
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• 2005

At present, fatigue design of welded structures is primarily based on a nominal stress or hot spot stress approach with a series of classified weld S-N curves. Although well accepted by major industries, the nominal stress based fatigue design approach is cumbersome in terms of securing a series of S-N curves corresponding to each class of joint types and loading modes. The hot spot stress based fatigue design has a difficulty of finding a proper stress through the global model, the midium size model, and the detail model of ship structure. Also, it is difficult to link proper displacements within three different mesh size models. Recently, the structural stress is proposed as a mesh-size insensitive structural stress definition that gives a stress state at weld toe with relatively large mesh size. However, this method requires an experimental validation in obtaining the fatigue strength of weldments. Therefore, in this study, a series of experiment is performed for various sizes of weldments.

• Steel and Composite Structures
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• 제46권6호
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• pp.805-821
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• 2023

This study developed an evaluation system to explore the effect of the environmental temperature on the stress redistribution produced by cable stress relaxation of structural members in a steel cable-stayed bridge. The generalized Maxwell model is used to estimate stress relaxation at different temperatures. The environmental temperature is represented using the thermal coefficients and temperature loads. The fmincon optimization function is used to determine the set of stress relaxation parameters at different temperatures for all cables. The ABAQUS software is employed to investigate the stress redistribution of the steel cable-stayed bridge caused by the cable stress relaxation and the environmental temperature. All of these steps are set up as an evaluation system to save time and ensure the accuracy of the study results. The developed evaluation system is then employed to investigate the effect of environmental temperature and cable type on stress redistribution. These studies' findings show that as environmental temperatures increased up to 40 ℃, the redistribution rate increased by up to 34.9% in some girders. The results also show that the cable type with low relaxation rates should be used in high environmental temperature areas to minimize the effect of cable stress relaxation.

• 한국가정과교육학회지
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• 제20권1호
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• pp.1-19
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• 2008

본 연구는 청소년기 남자 중학생을 대상으로 스트레스 정도와 식행동 실태를 조사하고, 스트레스가 식행동에 미치는 영향을 분석하였다. 스트레스 요인으로 가족, 학업, 오락, 건강, 동성친구, 이성 친구, 교사, 일상생활의 8개 영역, 식행동 요인으로 식사의 규칙성과 균형성, 건강식의 3개 영역으로 구분하여 분석하였다. 대전 중구 지역에 위치한 남자 중학생 140명을 대상으로 2006년 7월 10일부터 7월 14일 사이에 설문조사를 실시하였으며, 수집된 설문지 140부 중 총 128부(91.4%)를 최종 분석에 사용하였다. 연구의 결과를 요약하면 첫째, 조사대상자의 스트레스 실태는 5점 만점에 평균 2.36으로 중간 정도 수준이었다. 영역별 차이는 크지 않았으며, 학업 영역에서의 스트레스(2.93)가 높았고, 이성 친구 관련 스트레스(1.96)가 낮았다. 둘째, 식행동 점수는 5점 만점에 3.02로 중간 수준이었다. 셋째, 스트레스 정도에 따라 낮은 군, 중간 군, 높은 군의 3개 집단으로 구분하였을 때, 중간 군의 식행동 점수가 가장 높았고 높은 군의 식행동 점수가 가장 낮았으나 유의한 차이는 아니었다. 넷째, 스트레스와 식행동의 상관관계를 살펴본 결과, 스트레스 총점은 식생활 균형성과 상관이 있었으며, 규칙성은 가족, 학업, 건강 관련 스트레스와 상관관계가 있는 것으로 확인되었다. 즉 가족, 학업, 건강 관련 스트레스를 많이 받을수록 규칙성 점수는 낮았다.

• 한국간호교육학회지
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• 제4권2호
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• pp.317-330
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• 1998

A descriptive-explanatory design was employed in this study. The purpose of this study was identify the level of assertiveness and clinical stress and the relationships between assertiveness and clinical stress in nursing students. A convenient sample of 143 nursing students was used for the study. The results of this study are as follows : 1) The level of assertiveness of nursing students was 3.65 in domain of contents, 3.68 in domain of voice, and 4.13 in domain of body language. Thus the level of asertiveness of nursing students was higher in body language. 2) The level of clinical stress of nursing students was 3.73 in domain of clinical education and evaluation by professors, 3.59 in domain of nurses, 3.32 in domain of human relationships, and 3.30 in domain of environment. Thus the level of clinical stress of nursing students was higher in clinical education and evaluation by professors. 3) The assertiveness of nursing students was found significantly related to human relationships. 4) The clinical stress of nursing students was found significantly related to satisfaction of nursing, satisfaction of clinical practice and priority of candidate for nursing. 5) The assertiveness of nursing students was not found significantly related to clinical stress in nursing students.

• 가정과삶의질연구
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• 제24권1호
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• pp.209-221
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• 2006

The purpose of this study was to investigate emotional intelligence and stress coping styles of adolescents. The study also identified the differences of emotional intelligence and stress coping styles between normal adolescents and juvenile delinquents. The subjects in this study were 447 adolescents included 249 normal adolescents and 198 juvenile delinquents. The major findings as follows: First, there were significant differences on emotional intelligence between normal adolescents and juvenile delinquent. Normal adolescents had higher level of emotional intelligence. However there were no significant differences on stress coping styles except wishful thinking between normal adolescents and juvenile delinquent. Second, there were overall positive correlation between emotional intelligence and stress coping styles. However regulation of emotion showed negative correlation with stress coping styles. The result of Canonical Correlation revealed that emotional facilitation of thinking among five sub-domains of emotional intelligence was the best contributor to predict stress coping styles of adolescents.