• 대한기계학회논문집A
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• 제21권11호
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• pp.1965-1971
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• 1997

The relaxation of stress concentration in notched members can be very significant in the improvement of notched strength and fatigue life. This paper investigated the relationship of stress concentration factor, and notched strength and fatigue life. The stress concentration factors were analyzed by FEM. Uniaxial tensile and fatigue tests were carried on plain woven composite specimens which have a main hole and two defence holes. From experimental results, the notched strength and the fatigue limit increased up to about 50% and 30% respectively due to the reduction in stress concentration. The fatigue lives predicted by Juvinall's approach were underestimated than test results and this trends were remarkable as nothed strength increased. This is because of the underestimation of a coefficient. A in S-N curve (.sigma.$_{ar}$ =A $N_{f}$ $^{B}$). Therefore, considering notched strength the coefficient A was modified. The fatigue lives by this process were agreed well with the experimental results.sults.

• 대한기계학회논문집A
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• 제29권11호
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• pp.1542-1550
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• 2005

This paper presents the numerical procedure for calculating non-uniform residual stresses based on relieved displacements obtained from incremental hole drilling. The relationship between the in-plane displacement produced by introducing a blind hole and the corresponding residual stress is established. Finite element calculations are described to evaluate the relieved coefficients required for the determination of non-uniform residual stresses. Validity of the proposed method has been tested through three axisymmetric test examples and two three-dimensional examples. As a result of . simulation on the test examples, it is found that this numerical procedure is well adopted to measuring non-uniform residual stress in the full hole depth range of the hole diameter from the surface. The accuracy of the hole drilling method with displacement measurement is discussed, comparing tile method with strain measurement

• Structural Engineering and Mechanics
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• 제30권3호
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• pp.351-368
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• 2008

The purpose of this paper is to propose a simple analysis method of axial deformation of base-isolation rubber bearings in a building subjected to earthquake loading and present its applicability to the analysis of the bound of the aspect ratio of base-isolated buildings. The base shear coefficient is introduced as a key parameter for the bound analysis. The bound of the aspect ratio of base-isolated buildings is analyzed based on the relationship of the following four quantities; (i) ultimate state of the tensile stress of rubber bearings based on a proposed simple recursive analysis for seismic loading, (ii) ultimate state of drift of the base-isolation story for seismic loading, (iii) ultimate state of the axial compressive stress of rubber bearings under dead loads, (iv) prediction of the overturning moment at the base for seismic loading. In particular, a new recursive analysis method of axial deformation of rubber bearings is presented taking into account the nonlinear tensile behavior of rubber bearings and it is shown that the relaxation of the constraint on the ultimate state of the tensile stress of rubber bearings increases the limiting aspect ratio.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.258-261
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• 2007

Simulations of the thermally-induced residual stresses and birefringence in freely quenched plates of polycarbonate were performed by using the linear viscoelastic and photoviscoelastic constitutive equations for the mechanical and optical properties, respectively, and the first order rate equation for volume relaxation. The predictions for the birefringence showed good agreement with experimental measurements. Based on the simulation, the influences of various cooling conditions on the residual stress and birefringence in plates were investigated. The residual stress and birefringence increased with increasing initial temperature, decreasing coolant temperature and increasing heat transfer coefficient of coolants.

• 대한가정학회지
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• 제26권3호
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• pp.93-102
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• 1988

Rheological properties of cowpea and mung bean starch gels and pastes were investigated and compared with Instron Universal Testing machine and Brabender Viscometer. As the result of puncture test of gels, yield point force of mung bean starch gel was higher than that of cowpea starch gel. Compression coefficient of cowpea starch gel calculated by Bourne's equation was lower than that of mung bean starch gel. the stress relaxation test showed that viscoelastic properties of cowpea and mung bean starch gels may be represented by six element Maxwell model consisting of three Maxwell element in parallel. Cowpea and mung bean starch pastes showed bingham pseudoplastic behavior in 3, 5, 6, 7 and 8%. The consistency index in 7∼8% of cowpea starch paste were lower than those of mung bean starch paste. concentration dependence on consistency index and yield stress in mung bean starch were higher than those of cowpea starch. The yield stress of starch pastes was significantly correlated with yield point force by puncture test (r=0.996).

• 한국융합학회논문지
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• 제9권11호
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• pp.561-567
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• 2018

본 연구는 중년남성의 가족스트레스와 직무스트레스가 우울에 영향을 미치는 영향력을 파악하기 위해 시도 되었다. 본 연구는 C시와 K시 지역에 거주하는 직장인 중년남자 127명을 대상으로 한 서술적 조사연구이며 자료는 SPSS 21.0을 이용하여, 기술통계, ANOVA, t-test, Pearson's correlation 상관분석 및 다중희귀분석으로 실시하였다. 자료수집은 2018년 7월 1일 부터 2018년 8월 20일 까지 하였다. 본 연구결과는 다음과 같다. 중년남성의 일반적 특성에 따른 가족스트레스, 직무스트레스, 우울의 차이는 경제상태와 노후불안정도에서 유의미한 차이를 보였다. 우울에 영향을 미치는 변수는 직무스트레스(${\beta}=0.288$, p<.001), 노후불안정도(${\beta}=0.142$, p<.001), 경제상태(${\beta}=0.035$ p<.001), 가족스트레스(${\beta}=0.016$ p<.001)순으로 확인되었다. 가족스트레스와 직무스트레스를 줄이기 위한 해소방법으로는 운동, 취미생활, 신체이완 등 건강관리와 가족갈등 다루기를 해야 할 것이며 이는 우울을 예방하고 우울수준을 낮출 수 있는 간호중재 프로그램을 개발하는 것이 필요할 것이다.

• 보건교육건강증진학회지
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• 제18권3호
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• pp.117-131
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• 2001

This study was attempted to develope a highly reliable and valid tool which is useful to assess the Korean obese adolescents' stress and coping method. The data were collected from the total of 600 obese students from middle and high schools in Pusan. The author used a convenience sampling method. The data collection was done from March 2 to July 11, 1999. The analysis of the data was done with SPSS Win(10.0) for descriptive statistics and factor analysis. The preliminary tool was composed of 72 items(stress items: 34, coping method items: 38) with the five point Likert scale. Item analysis and inter consistency were calculated for reliability and validity through pre-test. The preliminary tool was analyzed for reliability and validity. Finally, the tool was of 65 items(stress items: 33, coping method items: 32). The results were as follows: 1. Cronbach Coefficient Alpha for the 33 items of stress was .9485 and the 32 items of coping method was .8534. 2. The factor analysis was done in order to confirm construction and the items were extracted Oblimin rotation and Maximum likelihood extraction method. 3. The factor analysis showed 6 factors in stress and 10 factors in coping method. These 6 factors of stress explained 62.4％ and 10 factors of coping method explained 57.4％. 4. Six factor of stress lable were 〈outward appearance〉, 〈boyfriend/ girlfriend〉, 〈occur an outbreak of disease〉, 〈mutual relation of family〉, 〈an obese figure〉, 〈be a burden on exercise〉. 5. Ten factor of coping method lable were 〈be concerned about another affairs〉, 〈recreation activities〉, 〈self-violence〉, 〈relaxation〉, 〈hobby activities〉, 〈avoid a situation〉, 〈communication〉, 〈music〉, 〈negative behavior〉, 〈positive thinking〉. The results of using this scale in a study will contribute to design an appropriate school health management of obese students, and also it will contribute to the development of nursing research.

• 성인간호학회지
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• 제13권2호
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• pp.317-326
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• 2001

The purpose of this study was to identify correlation of stress, coping patterns and physical symptoms in cancer patient's caregiver. The stress was measured by VAS(Visual Analogue Scale). The coping methods were measured using the modified Ways of Coping Questionnaire by Yang (1998) and the actual physical symptoms were investigated. The phases of patient illness consisted of 1st (initial) stage, and 2nd (recurred) stage and 3rd (terminal) stage based on literature (Lewandowski & Jones, 1988). The data were collected by a survey conducted from March to July, 2000 and which included 196 cancer patients' caregivers from two hospitals in Seoul. The data were analyzed using paired t-test, unpaired t-test, ANOVA, Scheffe test and Pearson correlation coefficient. The results were as follows: 1. The average of caregivers' stress scores was 62.5. Problem-focused coping methods were significantly used more than emotion-focused coping methods by the cancer patients' caregiver. The mean number of caregivers' physical symptom was 1.03. 2. There were significantly high level of stress in women, those who were more than 60 years old, those who had a low education level, those who had no job, those who are patients' wives' and those who are terminal patients' caregiver. There were significantly low levels of coping in women, those who were more than 60 years old, those who had low education levels, those who had no job and those who are patients' wives. There were significantly higher number of physical symptoms in women, and those who have no job. 3. Caregivers' stress was significantly correlated to problem-focused coping methods (r=-.21, p=.006), and physical symptom (r=-.28, p=.0001). In conclusion, attempts to develop nursing interventions for cancer patients' caregiver in women, those who are more than 60 years old, with a low education level, have no job, and are cancer patients' wives could have an improvement on positive coping methods and provide relaxation from stress in the patients' experience.

• 대한간호학회지
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• 제28권3호
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• pp.540-549
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• 1998

This study has been designed to develop a health behavior scale. Data were collected through a survey over a period of two month period. Subjects who participated in the study were 298 Korean adults. The author used a convenience sampling method. The analysis of the data was done with SPSS PC for descriptive statistics and factor analysis. Initially 34 items were generated from the interview data of twenty one adults and from literature review and survey. This preliminary scale was analyzed for a reliability and validity. The results are as follow : 1. Crombach Coefficient alpha for the 30 items was .7907. 2. Factor analysis was done in order to confirm construct validity and nine factor were extracted from the results. These contributed 54.4% of the variance in the total score. 3. Nine factor label were 'exercise' 'stress management' 'energy conservation' 'limit in liking' 'selection of food' 'ingestion of natural food' 'health examination' 'relaxation' and 'nutrition'. The author suggests that this scale could be adequately applied in assessing the health behavior of Korean adults. The results of using this scale in a study can contribute to designing an appropriate health promotion strategy.

• 대한기계학회논문집B
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• 제31권1호
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• pp.40-50
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• 2007

The present contribution describes the application of elliptic-blending second moment closure to predict the gas cooling process of turbulent super-critical carbon dioxide flow in a square cross-sectioned duct. The gas cooling process under super-critical state experiences a drastic change in thermodynamic and transport properties. Redistributive terms in the Reynolds stress and turbulent heat flux equations are modeled by an elliptic-blending second moment closure in order to represent strongly non-homogeneous effects produced by the presence of walls. The main feature of Durbin's elliptic relaxation second moment closure that accounts for the nonlocal character of pressure-velocity gradient correlation and the near-wall inhomogeneity guaranteed by the elliptic blending second moment closure.