• 한국안전학회지
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• 제9권4호
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• pp.29-41
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• 1994

High temperature tensiles tests, steady state creep tests, internal stress tests and creep rupture tests using Al 7075 alloy were performed over the temperature range of 9$0^{\circ}C$~50$0^{\circ}C$ and stress range of 0.64~17.2(kgf/$\textrm{mm}^2$) in order to investigate the creep behavior and predict creep rupture life From the apparent activation energy Qc and the applied stress exponent n measured, at the temperature range of 9$0^{\circ}C$~l2$0^{\circ}C$, the creep deformation seemed to be controlled by cross slip. On the other hand at the temperature of 20$0^{\circ}C$~23$0^{\circ}C$ the creep deformation seemed to be controlled by dislocation climb but at 47$0^{\circ}C$~50$0^{\circ}C$, by diffusion creep. And the rupture life(t$_{f}$) might be represented by anthermal process attributed to the difference of the applied stress dependence of Internal stress and the ratio of the Internal stress to the applied stress, the thermal activated process attributied to the temperature dependence of the internal stress. Also the ratio between stress dependence of primary creep rate and that of minimum creep rate was measured 0.46, the minimum creep rate is expected to be appromately obtained from master creep curve including the relationship primary creep rate and minumum creep rate. Finally the relationship new rupture parameter and logarithmic stress was represented with including the ratio between the dependence of primary creep rate and that of minimum creep rate, using the new rupture parameter the rupture life predition is exactly expected.d.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.370-374
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• 2010

A gene encoding the major secreted fibrinolytic protein of Bacillus amyloliquefaciens CH86-1 was cloned from genomic DNAs. DNA sequencing showed that the gene, aprE86-1, could direct the synthesis of a mature protein 275 amino acids in length after processing. When aprE86-1 was introduced into B. subtilis, a mature 27-kDa protein was produced as expected. The fibrinolytic activity of the B. subtilis transformant (TF) was higher than that of B. amyloliquefaciens CH86-1, showing the possibility of increasing the fibrinolytic activity of Bacillus strains through genetic engineering.

• 한국간호교육학회지
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• 제9권2호
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• pp.244-252
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• 2003

This study was intented to identify the differences of fatigue and quality of life in patients with breast cancer according to the different treatment modalities. Ninety-one subjects were recruited from a medical unit and a therapeutic radiologic clinic at a university hospital in Chungnam, Korea. Fatigue was measured using Lee's scale(1999) translated from Piper's Fatigue Scale and quality of life was measured using Yang's scale(2002). The women with breast cancer receiving chemotherapy were less fatigued and had better quality of life than those receiving radiotherapy(t=-2.914, p=.005; t=2.565, p=.012, respectively). The fatigue and quality of life in the women with breast cancer undergoing cancer treatments were influenced by the weight change during the past 3 months(F=24.70, p=.039). Cancer stage, metastasis and weight were not associated with fatigue and quality of life. Health professionals can help cancer patients undergoing treatments prepare to cope with the expected side effects by providing a specific treatment-related information to them. The findings of this study can contribute the knowledge of these information.

• 기본간호학회지
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• 제8권2호
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• pp.199-209
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• 2001

The purpose of this study was to examine the relationship between life stress and depression, and the effect of social support in postpartal $4{\sim}6$ week women. Theoretically social support is thought to mediate the relationship between life stress and depression. Data were collected from June 1 to July 30, 1999. The data were analysed by use of SPSS. Two hypotheses were tested using Gamma, a measure of association for ordinal variables. Partial gamma was used to test the third hypothesis. Patterns of elaboration described by Babbie(1986) were selected to interpret the relationship of the three variables in the analyses. The results of this study are summarized as follows ; There was a positive relationship between life stress and depression (Gamma=.45, P=.017), and an inverse relationship between social support and depression (Gamma=-.49, P=.009). Thus the first, two hypotheses were supported. 2. When social support was controlled, the relationship between life stress and depression increased under the condition of low social support, but with high social support, the relationship decreased. It can be interpreted that life stresses are positively related to depression under the condition of low social support, however this relationship cannot be expected with high social support.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.23-30
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• 2011

International cooperation to reduce greenhouse gas emissions is expected to provide a big crisis and a great opportunity at the same time for our industry that heavily consumes energy. To cope actively with the international environmental regulation, such as the Framework Convention on Climate Change, quantitative measurement of the volume of greenhouse gases emitted by various industries and quantitative prediction of the greenhouse gas emissions of the future are becoming more important than anything else at the national level. This study aims to propose the calculation process of carbon dioxide($CO_2$) emission for building in life cycle. This paper describes and compares 9 different tool for environmental load estimation with LCA. This study proposed the calculation process for quantitatively predicting and assessing $CO_2$ emissions during the life cycle of buildings based on the life cycle assessment(LCA). The life cycle steps of buildings were divided into the design/supervision, new construction, repair, renovation, use of operating energy in buildings, maintenance, and reconstruction stage in the life cycle inventory analysis and the method of assessing the environmental load in each stage was proposed.

• Structural Engineering and Mechanics
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• 제73권4호
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• pp.455-462
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• 2020

The hybrid method using the extended finite element method (XFEM) and the forward Euler approach is widely employed to predict the fatigue life of plate structures. Due to the accuracy of the forward Euler approach is determined by a small step size, the performance of fatigue life prediction of the hybrid method is not agreeable. Instead the forward Euler approach, a prediction method using midpoint method and support vector regression (SVR) is presented to evaluate the stress intensity factors (SIFs) and the fatigue life. Firstly, the XFEM is employed to calculate the SIFs with given crack sizes. Then use the history of SIFs as a function of either number of fatigue life cycles or crack sizes within the current cycle to build a prediction model. Finally, according to the prediction model predict the SIFs at different crack sizes or different cycles. Three numerical cases composed by a homogeneous plate with edge crack, a composite plate with edge crack and center crack are introduced to verify the performance of the proposed method. The results show that the proposed method enables large step sizes without sacrificing accuracy. The method is expected to predict the fatigue life of complex structures.

• Smart Structures and Systems
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• 제30권6호
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• pp.571-582
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• 2022

Optimal life-cycle management is a challenging issue for deteriorating regional bridges. Due to the complexity of regional bridge structural conditions and a large number of inspection and maintenance actions, decision-makers generally choose traditional passive management strategies. They are less efficiency and cost-effectiveness. This paper suggests a deep reinforcement learning framework employing double-deep Q-networks (DDQNs) to improve the life-cycle management of deteriorating regional bridges to tackle these problems. It could produce optimal maintenance plans considering restrictions to maximize maintenance cost-effectiveness to the greatest extent possible. DDQNs method could handle the problem of the overestimation of Q-values in the Nature DQNs. This study also identifies regional bridge deterioration characteristics and the consequence of scheduled maintenance from years of inspection data. To validate the proposed method, a case study containing hundreds of bridges is used to develop optimal life-cycle management strategies. The optimization solutions recommend fewer replacement actions and prefer preventative repair actions when bridges are damaged or are expected to be damaged. By employing the optimal life-cycle regional maintenance strategies, the conditions of bridges can be controlled to a good level. Compared to the nature DQNs, DDQNs offer an optimized scheme containing fewer low-condition bridges and a more costeffective life-cycle management plan.

• 디지털융복합연구
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• 제11권7호
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• pp.225-235
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• 2013

본 연구는 도시지역 노인의 삶의 질 정도 및 삶의 질에 영향을 미치는 요인을 파악하기 위한 목적으로 수행하였다. 2012년 10월 2일부터 10월 25일까지 부산광역시에 소재한 4개의 노인대학에 다니는 65세 이상의 노인 300명을 대상으로 설문조사 수집하였으며 최종 245부를 분석하였다. 노인의 삶의 질 정도를 파악하였고, 삶의 질 영역간의 상관관계 분석과 다중회귀분석을 통해 삶의 질에 미치는 요인들을 분석하였으며 주요 결과는 다음과 같다. 첫째, 도시 노인의 삶의 질 평균평점은 3.17(5점척도)로 중간정도의 결과를 나타냈다. 둘째, 연구대상자의 삶의 질 하위영역별간에는 우울영역을 제외한 모든 영역 간에서 유의미한 양의관계를 보였다. 셋째, 삶의 질에 가장 영향을 주는 요인으로는 심리적 건강, 사회적 관계, 신체적 관계 순으로 유의한 수준을 보였다(p<0.001). 본 연구결과를 토대로 삶의 질에 심리적 건강인 우울증상이 주요 요인으로 나타난 만큼 우울증 완화를 시킬 수 있는 간호중재와 프로그램의 적용방안이 요구된다.

• 가정과삶의질연구
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• 제7권2호
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• pp.213-223
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• 1989

Decision frameworks for product safty policy are developed in theory and practice. Product characteristic approach and expected utility analysis are applied to situations involving risk and misinformation. Eight types of regulatory frameworks are explained and critiqued form practical purposes on behalf of consumer policy makers. Various international organizations and their roles are briefly reviewed.

• 한국식품조리과학회지
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• 제31권2호
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• pp.162-174
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• 2015

The purpose of this study was to evaluate the current status of dietary habits and dietary life competency of elementary school parents, who are influential to the dietary life of their children and family. A survey was conducted with 362 elementary school parents living in Seoul and Gyeonggi province by using a self-administered questionnaire consisting of 53 questions on dietary habits, dietary life competency, home cooking frequency, and dietary education needs. The results were as follows: The scores of dietary habits and dietary life competency were 76.35 and 74.51 out of 100, respectively, suggesting a need for improvement. Parents with higher monthly income, demonstrated higher scores of both dietary habits and dietary life competency (p<0.001). As expected, female parents showed higher scores of dietary life competency than male parents (p<0.01). there was also a close relationship between the scores of dietary habits and dietary life competency (r=0.58). The parents with high scores for dietary habits and dietary life competency showed a significantly higher frequency of home cooking (p<0.001) compared to medium- or low-scored parents. Most parents answered that dietary education need to be started earlier, and that their main source of dietary life information was mass media. They also showed a preference for real experience and practice for dietary education. The above results showed that there is a close relationship between dietary habits and dietary life competency, and suggest that continuous education is necessary to improve the dietary habits and dietary life competency of elementary school parents. Because monthly income appeared to be the most influential socioeconomic factor for the parents' dietary habits and dietary life competency, continuous efforts on dietary education are necessary to reduce the score gaps in these categories.