• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 춘계학술대회 논문집(Proceeding of the KOSME 2000 Spring Annual Meeting)
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• pp.122-126
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• 2000

In particle or short-fiber reinforced composites cracking of the reinforcements is a significant damage mode because the broken reinformcements lose load carrying capacity . The average stress in the inhomogeneity represents its load carrying capacity and the difference between the average stresses of the intact and broken inhomogeneities indicates the loss of load carrying capacity due to cracking damage. The composite in damage process contains intact and broken reinforcements in a matrix, An incremental constitutive relation of particle or short-fiber reinforced composites including the progressive cracking damage of the reinforcements have been developed based on the Eshelby's equivalent inclusion method and Mori-Tanaka's mean field concept. influence of the cracking damage on the Eshelby's equivalent inclusion method and Mori-Tanaka's mean field concept. Influence of the cracking damage on the stress-strain response of the composites is demonstrated.

• 항공우주시스템공학회지
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• 제15권6호
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• pp.19-25
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• 2021

This paper presents a method that uses the stress failure criteria to predict the tensile failure strength of open-hole laminates with stress concentrations. The composite material used in this study corresponds to a 177 ℃ cured, carbon/epoxy unidirectional tape prepreg. The results obtained by testing ten different laminates were compared and analyzed to verify the tensile strength of the open-hole laminates predicted using the proposed stress failure criteria. The findings of this study confirm that the tensile strength predictions performed using the proposed method are generally accurate, except in cases involving highly soft laminates (10% of 0° ply).

• 한국직업건강간호학회지
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• 제18권2호
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• pp.232-241
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• 2009

Purpose: This study was conducted to estimate the job stress and depression of female and male service workers and to determine the predictors influencing depression. Method: In this cross-sectional study, the data were collected from hotel, wholesale, and insurance companies. A total of 244 workers were recruited. Among them, 118 were female workers. A self-administered questionnaire was consisted of personal characteristics, job stress, daily life stress, social support, and depression. Depression was measured using a CES-D Korean version. Result: The average job stress of female workers was higher than that of male workers (P<.05). The average depression scores of female workers were higher than those of male workers, but the difference was not statistically significant. Multiple regression analysis showed that role conflict and low social support were significant predictors of depression in female workers. In male workers, role conflict, low social support, and under-utilization of abilities were significant predictors of depression. Conclusion: The results of this study suggest that depression of service workers may be prevented by creating a workplace environment that focuses on role conflict and social support. Also, health providers should consider the vulnerability of working women to job stress.

• 한국치위생학회지
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• 제3권2호
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• pp.101-116
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• 2003

The purpose of this study was to identify the personality type and stress coping method of students of Dept. dental hygiene students and relationship between them. Second purpose of this study was to suggest the good and useful method of stress coping. Data was drawn from a convenient sample of 350 and 3rd year students of the department of dental hygiene, some college located in Kyung-Ki Province. The results were analyzed with SPSS 10.0 and the conclusion is as follow: 1. The average of Machiavellism type is 3.30, which indicates that most of the students has a middle type(80%). In the A/B type, most of the students has B type(46.7%). In the score of externality and internality, externality(62.6%) is higher than internality(20.3%) 2. As a result of investigating how they coped with stress, the direct coping was utilized most and the physical was utilized least. 3. In the relation between the personality type and stress coping method, non-Machiavellism type has a statistically significant difference, in the direct coping and destructive coping.

• 기본간호학회지
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• 제25권4호
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• pp.293-300
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• 2018

Purpose: This study was done to identify the relationship between nurses' compliance with safety guidelines for the use of antineoplastic agents, observable symptoms, and stress from occupational exposure. Methods: The participants were 172 nurses from six general hospitals in a metropolitan area. They had administered antineoplastic agents at least three months prior to the study. Data were collected using self-report questionnaires, and then analyzed using SPSS/WIN 23.0 for descriptive statistics, t-test, one-way ANOVA, $Scheff\acute{e}$ method, and Pearson correlation coefficient. Results: The average score on the guideline for safety compliance was 87.75 points out of a total of 100. The average score for observable symptoms of exposure to antineoplastic agents was 30.12 (28~56) points, and that for mean stress was 33.52 (15~60) points. Observable symptoms and stress from occupational exposure showed a statistically significant positive correlation (r=0.34, p<.001). Conclusion: To increase the degree of compliance with safety guidelines for antineoplastic agents, hospitals should lower the chance of exposure to antineoplastic agents, as well as minimize the observable symptoms and stress from occupational exposure. Periodic education and policy support are needed to improve compliance with safety guidelines for antineoplastic agent use.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.481-486
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• 1997

In the paper, a simplified method for nonlinear analysis of reinforced concrete structures is presented, which is based on timeoshenko beam theory and constitutive equations that are given by the relation of average stress and average strain for concrete and reinforcing bars. Especially, this method consider shear deformation and determine the failure mode. In this paper, 1-D beam element model and program considering shear deformation are suggested. In addition, program procedure is presented briefly and the results are plotted with test examples.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 추계학술대회 논문집
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• pp.287-292
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• 1998

In particle or short-fiber reinforced composites. cracking of the reinforcements is a significant damage mode because the broken reinforcements lose load carrying capacity. This paper deals with the load carrying capacity of intact and broken ellipsoidal inhomogeneities embedded in an infinite body and a damage theory of particle or short-fiber reinforce composites. The average stress in the inhomogeneity represents its load carrying capacity. and the difference between the average stresses of the intact t and broken inhomogeneities indicates the loss of load carrying capacity due to cracking damage. The composite in damage process contains intact and broken reinforcements in a matrix. An incremental constitutive relation of particle or short-fiber reinforced composites including the progressive cracking damage of the reinforcements have been developed based on the Eshelby's equivalent inclusion method and Mori and Tanaka's mean field concept. Influence of the cracking damage on the stress-strain response of the composites is demonstrated.

• Journal of Power Electronics
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• 제12권3호
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• pp.410-417
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• 2012

In this paper, a direct current control method based on a one-cycle controller (DCOCC) for double frequency buck converters (DF buck) is proposed. This control method can make the average current through the high frequency and low frequency inductors of a DF buck converter equal. This is similar to the average current control method. However, the design of the loop compensator is much easier when compared with the average current control. Since the average current though the high frequency and low frequency inductors is equivalent, the current stress of the high frequency switches and the switch losses are minimized. Therefore, the efficiency of the DF buck converter is improved. Firstly, the operation principle of DCOCC is described, then the small signal models of a one cycle controller and a DF buck converter are presented based on the state space average method. Eventually, a system block diagram of the DCOCC controlled DF buck is established and the compensator is designed. Finally, simulation and experiment results are given to verify the correction of the theory analysis.

• 간호행정학회지
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• 제13권2호
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• pp.184-190
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• 2007

Purpose: This study was undertaken in order to suggest self-leadership as a method for nurses to lower their job stress and enhance their job satisfaction. So the relations among self-leadership, job stress and job satisfaction were studied. Method: The subjects of study were 123 nurses who have been working in 2 general hospitals located in K city. The data were collected by Q & A and analyzed using descriptive statistics, Pearson's correlation coefficient, t-test, and ANOVA on SPSS Program. Result: Nurses got average 3.50, 2.64 and 3.12 points out of 5 in their self-leadership, job stress and job satisfaction respectively. The self-leadership was negatively correlated with job stress (r=-.429, p=<.001) while it is positively correlated with job satisfaction(r=.281, p=<.001). And job stress was negatively correlated with job satisfaction(r=-.574, p=<.001). Job stress had statistically significant differences according to age and marital status. Conclusion: In conclusion self-leadership is correlated with job stress and job satisfaction. It is recommend that hospital managers have to develop methods which enhance self-leadership of nurses.

• 한국방재학회 논문집
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• 제6권3호
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• pp.9-16
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• 2006

기존 대부분의 구조물 건전도 모니터링 시스템에서는 제한적인 위치와 범위에서의 변형률 계측이 가능한 국부 변형률 센서를 이용하여 구조물 또는 구조 부재의 부재력을 계측하고 이에 기반하여 구조 안전성을 평가하고 있다. 그러나 실 구조물의 부재력 계측을 통한 안전성 평가는 하중의 크기 및 분포에 대한 불확실성 등의 다양한 이유로 부재 내 최대응력 작용점을 정확하게 파악하기 어렵다. 이러한 경우 구조물의 사이즈에 비하여 센서의 길이가 미소한 국부 변형률 센서를 이용한 안전성 평가의 적절성은 센서의 위치 및 개수에 좌우되는 한계를 가지게 된다. 이러한 한계를 극복하기 위하여 센서의 수를 증가시키면 처리해야하는 데이터의 양과 비용이 증가하게 되므로 현실적인 적용성에 문제점을 가지게 된다. 그러므로 본 연구에서는 이러한 한계와 문제점을 극복할 수 있는 대안으로 장대광변형센서에 의한 평균변형률을 이용한 보-기둥의 부재력 계측 기법을 제시하였다.