• Computers and Concrete
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• 제30권1호
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• pp.9-17
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• 2022

This paper discusses the effect of high temperatures (T_s) on the compressive strength and stress-strain curve of recycled fine aggregate concrete (RFAC), based on the experimental results. A total of 90 prisms (100 mm×100 mm×300 mm) were tested. The results show that the compressive strength and elastic modulus of RFAC specimens decreased significantly with increasing T values. As T increased, the strain corresponding to peak stress decreased first when T<200℃ and then increased afterwards. With increasing T values, the stress-strain curves became flat gradually, the peak stress dropped gradually, and ε_p decreased when T<200℃ and increased in the T range of 400-800℃. A stress-strain relations for RFAC exposed to high T_s is proposed, which agree quite well with the test results and may be used to practical applications.

• 한국응용과학기술학회지
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• 제40권3호
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• pp.507-520
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• 2023

이 연구는 간호대학생의 신종감염병지식과 임상실습스트레스가 스트레스대처방식에 미치는 영향을 파악하고 이를 통해 자가성장하는 간호사를 육성할 실습교육 및 심리적 지원 전략의 근거를 제공하고자 한다. 연구 참여자는 서울 및 충북지역에 거주하는 간호대학생으로 2022년 9월 10일부터 10월 10일까지 총 259부의 자료를 수집하였다. 통계프로그램 SPSS 21.0을 활용하여 피어슨 상관계수를 통해 신종감염병지식, 임상실습스트레스, 스트레스대처방식 간의 상관관계를 분석하였고 진입(Enter)방식의 다중회귀분석을 통해 임상실습스트레스가 스트레스대처방식에 미치는 요인을 분석하였다. 연구결과, 실습교육환경, 업무부담으로 인한 임상실습스트레스와 적극적 스트레스대처방식 간에 양의 상관관계를 보였고(r=.17 p<.005, r=.15 p=.017), 대인관계 갈등, 환자와 갈등, 업무부담, 바람직하지 않은 역할모델로 인한 스트레스는 소극적 스트레스대처방식과 양의 상관관계(r=.18 p=.040, r=.28 p<.000, r=.17 p=.006, r=.19 p=.003)를 보였다. 임상실습만족도에서 만족한다(B=.25, p=.003), 실습교육환경 스트레스(B=.17 p=.004), 성별(B=-.19, p=.023)순으로 적극적인 스트레스대처방식 총 변화량의 15%를 설명하였고, 실습업무부담으로 인한 임상실습스트레스는 소극적인 스트레스대처방식 총 변화량의 7%를 설명하였다. 따라서 이 연구는 임상실습스트레스에 보다 적극적이고 자발적으로 대처할 수 있도록 상담이나 교육프로그램을 제안하는 근거가 될 것이다.

• 한국치위생학회지
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• 제11권6호
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• pp.913-922
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• 2011

Objectives : This study aims to analyze the factors and degree of stress, which dental hygienics students experience during the off-campus practical training period at university/general dental hospitals or dental hospitals/clinics, to strategically plan and operate an efficient practical training, and to exploit such data for development of the said students into professional dental hygienists by nurturing their abilities to effectively cope with the potential educational frustration, demotivation, and skepticism on their occupations in advance. Methods : The stress measurement tool is set for 38 questions in total, The grading system for each question is based on 5-point Likert scale, which interprets that the lower score demonstrates a higher level of stress. The data collected as above are analyzed by SPSS 19.0. Results : The satisfaction "Satisfactory" of extramural practice at departments of dentistry of university and general hospitals and dental hospitals and clinics is 48.3% and 37.7% respectively. Environment area (p<.001) and role & activity area (p<.05) showed a significant difference of stresses between practices at departments of dentistry of university and general hospitals and dental hospitals and clinics. For departments of dentistry of university and general hospitals, the stress in environment area was highest. On the contrary, students who did practices at dental hospitals and clinics showed that the stress is highest at role & activity area. There was a positive correlation of areas of environment, personal relations, role & activity, and ideal & value. However, there was no correlation between treatment fields. Conclusions : In conclusion, educational institutes need to conduct a specialized systematic research establishing close relationships extramural practice organs, in order to minimize students' stress resulting from extramural practices by type and to increase the effect of extramural practices.

• Structural Engineering and Mechanics
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• 제61권3호
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• pp.389-396
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• 2017

Concrete pavements are subjected to traffic and environmental loadings. Repetitive type of such loading cause fatigue distress which leads to failure by forming cracks in pavement. Fatigue life of concrete pavement is calculated from the stress ratio (i.e. the ratio of applied flexural stress to the flexural strength of concrete). For the correct estimation of fatigue life, it is necessary to determine the maximum flexural tensile stress developed for practical loading conditions. Portland cement association PCA (1984) and Indian road congress IRC 58 (2015) has given charts and tables to determine maximum edge stresses for particular loading and subgrade conditions. It is difficult to determine maximum stresses for intermediate loading and subgrade conditions. The main purpose of this study is to simplify the analysis of rigid pavement without compromising the accuracy. Equations proposed for determination of maximum flexural tensile stress of pavement are verified by finite element analysis.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.496-499
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• 2006

In this study, a practical method of shrinkage stress analysis on concrete slab in multi-story building is proposed, which considers both internal restraint and external restraint variation resulting from construction sequence. The shrinkage stress due to external restraint is obtained by multiplying relaxation coefficient to elastic shrinkage stress. The additional shrinkage stress due to internal restraint is obtained by residual strain of the elastic analysis. A verification example was analyzed and compared by the proposed method and commercial analysis program that is capable of time-dependent analysis of concrete. The results of 10-story example building show that the internal restraint of reinforcement increases the shrinkage stress considerably at the slabs under loose external restraint.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 춘계학술대회 논문집
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• pp.306-312
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• 1992

The prevention of roll breakage in hot rolling process is improtant to reduce maintenance cost and production loss. Rolling conditions such as the roll force and torque have been intensively studied to overcome the roll breakage. in the present work, a model for life prediction of work rolls under working condition was developed and discussed. The model consists of stress analysis, crack propagation, wear and fatigue calculation model. Roll life can be predicted by stress, crack depth and fatigue damage calculated from this model. The reliability of stress analysis is backed up by the FEM analysis. From the result of simulation using by pressent model, although the fatigue damage of back up roll reachs 80% of practical limit, that of workroll was less than 40%. In edge section of workroll stress amplification is found by wear and bender effect. We can judge that workroll failures are not due to fatigue damage, crack propagation by bending stress but stress amplification by wear and bender in present working condition.

• 대한가정학회지
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• 제38권11호
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• pp.115-126
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• 2000

This study investigated the relationship of demographic and psychological variables with job and family-related stress among 293 employed wives. We found that age, job types, working in weekend, and family cohesion significantly contributed to the explanation of job-related stress. We also found that job types, working in weekend, family adaptation, family cohesion, and employment motivation significantly contributed to explaining the variation of family-related stress. Job-related stress was more explained by demographic variables than psychological ones, whereas family-related stress was more explained by psychological variables than demographic ones. Practical implications of the current findings were discussed.

• International Journal of Concrete Structures and Materials
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• 제3권1호
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• pp.33-37
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• 2009

Fiber Bragg grating (FBG) sensors already have been the focus for structural health monitoring (SHM) due to their distinguishing advantages. However, as bare optical fiber is very fragile, bare FBG strain sensor without encapsulation can not properly be applied in practical infrastructures. Therefore encapsulation techniques for making encapsulated FBG strain sensor show very important in pushing forward the application of FBG strain sensors in SHM. In this paper, a simplified approximate method to analyze the stress transferring rules for embedded FBG strain sensors in concrete monitoring is put forward according to mechanics of composite materials. Shear lag theory is applied to analyze the stress transferring rule of embedded FBG strain sensor in measured host material at the first time. The measured host objects (concrete) and the encapsulated FBG strain sensor are regarded as a composite, and then the stress transfer formula and stress transfer coefficient of encapsulated FBG strain sensor are obtained.

• Perspectives in Nursing Science
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• 제13권1호
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• pp.10-16
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• 2016

Purpose: This study aimed to investigate differences in drinking scores according to stress and depression. Methods: A secondary analysis of the 5th and 6th Korea National Health and Nutrition Examination Surveys was conducted. Complex sampling design data analysis was performed in order to identify differences in Alcohol Use Disorder Identification Test (AUDIT) scores according to stress and depression among 1,732 unmarried women. Results: The average AUDIT score was 6.14 in unmarried women. There were significant differences in AUDIT scores in terms of stress and depression. Conclusion: Practical programs that can prevent alcohol drinking for unmarried women are suggested. Programs for alcohol-related problems should include stress and depression management.

• International Journal of Reliability and Applications
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• 제18권2호
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• pp.83-98
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• 2017

Stress-strength reliability problems arise frequently in applied statistics and related fields. In the context of reliability, the stress-strength model describes the life of a component, which has a random strength X and is subjected to random stress Y. The component fails at the instant that the stress applied to it exceeds the strength and the component will function satisfactorily whenever X > Y. The problem of estimation the reliability parameter in a stress-strength model R = P[Y < X], when X and Y are two independent two-parameter Lindley random variables is considered in this paper. The maximum likelihood estimator (MLE) and Bayes estimator of R are obtained. Also, different confidence intervals of R are obtained. Simulation study is performed to compare the different proposed estimation methods. Example in real data is used as practical application of the proposed procedure.