• 제목/요약/키워드: two stress factors

검색결과 953건 처리시간 0.024초

가중함수법을 이용한 두꺼운 배관의 응력강도계수 계산 (Calculation of Stress Intensity Factors for a Thick Pipe Using Weight Function Method)

  • 이형연;이재한;유봉
    • 대한기계학회논문집A
    • /
    • 제20권7호
    • /
    • pp.2167-2173
    • /
    • 1996
  • An approximate weight function technique using the indirect boundary integral equation has been presented for the analysis of stress intensity foactors(SIFs) of a thick pipe. One-term boundary integral was introduced to represent the crack surface displacement field for the displacement based weight function technique. An explicit closed-form SIF solution applicable to symmetric cracked pipes without any modification of the solution including both circumferential and radial cracks has been derived. The necessary information in the analysis is two or three reference SIFs. In most cases the SIF solution were in good agreement with those available in the literature.

강박스 거더교 콘크리트 바닥판에 발생하는 크리프, 건조수축, 수화열에 관한 연구 (A Study on Creep, Drying Shrinkage, Hydration Heat Produced in Concrete Floor Plate of Steel Box Girdler Bridge)

  • 강성후;박선준;김민성
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
    • /
    • pp.457-462
    • /
    • 2003
  • It studies the non-structural crack factors that are produced in Steel Box Girder Bridge concrete floor plate using analytical method. It mainly studies humidity and design standard of concrete strength. It used MIDAS CIVIL Ver 5.4.0, a general structure analysis program that applies drying shrinkage rate of domestic road bridge design standard and standard value of creep coefficient, CEF-FIP standard equation and ACI standard equation from the aspect of creep, drying shrinkage and hydration heat to see the effect of the two factors on concrete crack and found the following result. The analytical results of this study showed that the initial stress, which was obtained by ACI standard, exceeds the allowable tensile stress between 5 to 18 days. This result means that even if a bridge is designed and constructed according to design standard, the bridge can have cracks due to various variables such as drying shrinkage, hydration heat and creep that produce stress in slab.

  • PDF

Interlaminar stresses and delamination of composite laminates under extension and bending

  • Nguyen, Tien Duong;Nguyen, Dang Hung
    • Structural Engineering and Mechanics
    • /
    • 제25권6호
    • /
    • pp.733-751
    • /
    • 2007
  • The metis element method (Hung 1978) has been applied to analyse free edge interlaminar stresses and delamination in composite laminates, which are subjected to extension and bending. The paper recalls Lekhnitskii's solution for generalized plane strain state of composite laminate and Wang's singular solution for determination of stress singularity order and of eigen coefficients $C_m$ for delamination problem. Then the formulae of metis displacement finite element in two-dimensional problem are established. Computation of the stress intensity factors and the energy release rates are presented in details. The energy release rate, G, is computed by Irwin's virtual crack technique using metis elements. Finally, results of interlaminar stresses, the three stress intensity factors and the energy release rates for delamination crack in composite laminates under extension and bending are illustrated and compared with the literature to demonstrate the efficiency of the present method.

간호대학생들의 감성지능에 영향을 미치는 요인 (Factors influencing the Emotional intelligence in nursing students)

  • 유지형;이유미
    • 한국산업융합학회 논문집
    • /
    • 제20권5호
    • /
    • pp.385-393
    • /
    • 2017
  • The purpose of this study is explore stress, problem solving and emotional intelligence in nursing students. Participants were recruited from December 2016 to February 2017 by web base survey. The participants were 237 who nursing students in university. Stress, problem solving and emotional intelligence were assessed using two questionnaires; Korean version of the Perceived stress inventory (PSI), problem solving, and Wong and Law Emotional Intelligence Scale (WLEIS). The responses 237 students were analyzed statistically. Significantly emotional intelligence was a correlation stress and problem solving (p>.001). The findings showed that problem solving (${\beta}=.386$), stress (${\beta}=-.259$, empathy ability (${\beta}=.144$), and satisfaction with a major in nursing (${\beta}=.129$). Our finding show that stress levels of low and the problem solving levels of above moderate in emotional intelligence. Especially, the problem solving was important factor in emotional intelligence.

기공프로그램이 스트레스완화에 미치는 영향 (A Study of Stress-Control by Qigong Program)

  • 신용철
    • 대한예방한의학회지
    • /
    • 제11권2호
    • /
    • pp.133-139
    • /
    • 2007
  • In the study of Stress-Control by Qigong Program, the results were as follows : In modern society, many stress factors affect the human organism, altering and chipping away at our nervous, endocrine, locomotor, reproductive, digestive, respiratory, circulatory and immune systems. The beneficial effects of Qigong can help us to restore our equilibrium and enhance our quality of life. This study was performed to investigate the effect of Qigong on stress and psychological symptoms. Twenty-two subjects were trained Qigong Program a week for 8 weeks. The stress index of subjects and psychosomatic symptoms was compared before and after Qigong Program and was significantly decreased after Qigong training. It means that the stress index and psychosomatic symptoms were improved by Qigong training.

  • PDF

2-3세 자녀를 둔 어머니의 양육 신념, 효능감 및 스트레스가 양육 행동에 미치는 영향 (The Effects of Maternal Parental Beliefs, Efficacy and Stress on Mother s Parenting Behaviors)

  • 안지영;박성연
    • 대한가정학회지
    • /
    • 제40권1호
    • /
    • pp.53-68
    • /
    • 2002
  • The purpose of this study was to examine the effects of parental beliefs, efficacy and stress on mother's parenting behaviors. The subjects were 243 mothers of two to three-Year-old children in Seoul. The main results showed that parental beliefs, efficacy and stress were significantly related with parenting behaviors. That is, the resets of mutiple regression analysis indicated that parental efficacy, beliefs and stress were significant variables predicting mother's parenting behavior. However, the predictive powers of these variables were different depending on the characteristics of parenting behaviors. And the relationship between mother's parental stress and parenting behaviors was mediated by mother's parental efficacy. To conclude, mother's cognitions such as parental beliefs, parental efficacy, and a perception of parenting stress turned out to be the vital factors in predicting parenting behaviors.

혼합모우드를 받는 균열판의 응력확대계수 산정을 위한 p-Version 유한요소 모델 (p-Version Finite Element Model for Computation of the Stress Intensity Factors of Cracked Panels under Mixed Mode)

  • 윤영필;이채규;우광성
    • 전산구조공학
    • /
    • 제9권2호
    • /
    • pp.133-142
    • /
    • 1996
  • 본 논문에서는 혼합모우드형의 공학적 파괴역학을 위한 두가지 방법의 p-version유한요소모델을 사용한 응력확대계수 산정을 목적으로 연구되었다. 두 가지 방법은 COD와 CSD방법에 의한 변위외삽법과 분해법에 기초한 J-적분법이다. 즉, p-version 유한요소해석을 통해 얻어지는 변위장을 균열선에 대해 대칭 및 역대칭 변위로 분리함으로써, 앞에서 언급된 두가지 방법에 의해 모우드-I과 모우드-II 응력확대계수를 결정할 수 있다. 제안된 방법들의 검증을 위한 예제는 인장력을 받는 중앙균열판과 중앙 경사균열판 문제이다. 균열판의 경사각의 변화와 균열길이와 평판 폭의 비에 따른 수치해석결과는 기존 문헌에 있는 이론값과 경험식에 의한 결과와 비교되어 높은 정도를 보여주고 있다 .

  • PDF

대학병원과 개인병원 신장실 간호사의 스트레스 및 대처방법 비교 (Comparative Study on the Stress and the Coping Method between Nephrology Nurses Working in the Hospitals of University and the Hemodialysis Clinics)

  • 김경숙;이향련
    • 동서간호학연구지
    • /
    • 제9권1호
    • /
    • pp.46-56
    • /
    • 2004
  • Purpose: The purposes of this study are to examine and to compare factors causing stress and coping methods between nephrology nurses working in the Hospitals of University and the Hemodialysis Clinics. Method: Data were collected by a direct survey method using a questionnaire from August 13 to August 31, 2001. The sample of 137 nephrology nurses in the twenty-one Hospitals of University and 168 nephrology nurses in the twenty-six Hemodialysis Clinics were selected for a total sample of 305 nurses. Result: Stress according to general characteristics showed a significant difference in religion and in the level of satisfaction for their work. Stress score was the highest in the nurses whose religion was Buddhism(F=4.846, P=0.008) and in the group with 'dissatisfied' for the work in the Hemodialysis unit(F=3.193, P=0.014). The results analyzed coping method according to the general characteristics had a significant difference only in religion(F=16.237, P=0.000). The score for the coping method was the highest in Buddism. The score compared the satisfaction level for their work according to the hospital type, were 3.55 in the Hospital of University group and 3.35 in the Hemodialysis clinic group and these two values were significant different(p<0.05). The mean score of the stress nephrology nurses in the Hospitals of University is 2.79 and that of the stress nephrology nurses in the Hemodialysis clinics is 2.78 of 4 point scale. Among the factors causing stress, items related nursing work and conflict in nurse-patient relationship significantly caused more stress to the nephrology nurses in the Hospitals of University than to those in the Hemodialysis clinics(p<0.05). Conclusion: This study suggests that there were some differences in the stress and coping methods between nephrology nurses in the hospitals of University and the Hemodialysis clinics. Further study related to stress management program is needed to decrease stress and use effective coping methods.

  • PDF

노년기 연소노인, 중고령노인, 초고령노인 집단의 스트레스 요인과 자아존중감이 우울에 미치는 영향 - 자아존중감 2요인의 매개효과를 중심으로 - (The Effects of Stress factors and Self-Esteem on Depressive Symptoms among the young-old, the old-old, the oldest-old groups: The Mediating Role of Two Dimension Self-Esteem)

  • 권태연
    • 사회복지연구
    • /
    • 제40권1호
    • /
    • pp.163-196
    • /
    • 2009
  • 본 연구는 스트레스 대처이론을 토대로 노년기를 연소노인, 고령노인, 초고령노인 집단으로 구분하여 스트레스 요인들과 긍정적 자아존중감 및 부정적 자아존중감의 내적자원이 우울에 미치는 영향과 그 경로를 살펴보았다. 또한 자아존중감을 긍정적 자아존중감과 부정적 자아존중감의 2요인으로 구분하여, 스트레스 요인들과 우울의 관계에서 매개역할을 하는지 검증하였다. 연구를 위해 한국복지패널(Korea Welfare Panel Study) 1차년도 자료를 활용하였으며, 65세 이상인 가구원 4,338명을 최종 분석 대상으로 하여 구조방정식 모형을 사용하여 분석하였다. 분석결과, 노년기의 스트레스 요인들은 우울에 직접적인 영향을 미치기도 하고 긍정적 자아존중감 및 부정적 자아존중감을 통해 간접적으로 우울에 영향을 미치는 것으로 나타났다. 또한 다중집단분석결과, 노년기의 연령대별로 우울에 영향을 미치는 스트레스 요인과 자아존중감의 영향력과 경로가 다르게 나타났다. 이러한 연구결과를 토대로 노년기 우울의 예방과 치료를 위한 사회복지의 정책 및 실천적 함의를 제언하였다.

우울증의 후생유전적 기전의 역할 (Role for Epigenetic Mechanisms in Major Depression)

  • 김재원;윤봉준
    • 생물정신의학
    • /
    • 제18권4호
    • /
    • pp.181-188
    • /
    • 2011
  • Major depression is a devastating disorder of which lifetime prevalence rate is as high as up to 25% in general population. Although the etiology of the disorder is still poorly understood, it is generally accepted that both genetic and environmental factors are involved in the precipitation of depression. Stressful lifetime events are potent precipitating environmental factors for major depression and early-life stress is in particular an important element that predisposes individuals to major depression later in life. How environmental factors such as stress can make our neural networks susceptible to depression and how those factors leave long-lasting influences have been among the major questions in the field of depression research. Epigenetic regulations can provide a bridging mechanism between environmental factors and genetic factors so that these two factors can additively determine individual predispositions to major depression. Here we introduce epigenetic regulations as candidate mechanisms that mediate the integration of environmental adversaries with genetic predispositions, which may lead to the development of major depression, and summarize basic molecular events that underlie epigenetic regulations as well as experimental evidences that support the active role of epigenetic regulation in major depression.