• 한국지반공학회논문집
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• 제29권12호
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• pp.77-85
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• 2013

불포화 사면에서는 강우시 침투가 일어나고 포화가 됨에 따라 불안정해진다. 불포화토의 유효응력의 관점에서는, 모관흡수력이 감소하면 유효응력이 감소하고 동시에 전단강도도 감소하여 사면 안정성이 저해된다. 본 연구에서는 불포화토의 유효응력을 흡수응력으로 기술하는데 초점을 둔다. 그리고 유한요소응력장에서 안전율을 계산하여 실제 사면의 붕괴를 시뮬레이션한다. 하동 및 포항지역의 풍화토 지층에 대하여 실내실험을 수행하여 불포화 물성을 분석하였다. 그리고 불포화 사면의 침투 해석을 수행하고 응력해석과 안정해석을 통하여 실제 붕괴를 재현하였다. 따라서 불포화 유효응력 원리에 근거하여, 실제 사면의 안정성을 성공적으로 평가할 수 있었다. 유효응력 개념이 강우 침투를 고려한 사면 설계의 실무에 적용될 수 있음을 입증하였다.

• 대한간호학회지
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• 제37권4호
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• pp.529-539
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• 2007

Purpose: This quantitative meta analysis sought to determine the effectiveness of SMIs. Method: Forty-six experimental studies with a randomized or nonequivalent control group pre-post test design were included in the analysis. The selected studies were classified according to the sample characteristics, the types and methods of the interventions, and the types of outcome variables. Six intervention types were distinguished: cognitive-behavioral intervention(CBT), relaxation techniques(RT), exercise(EX), multimodal programs 1 and 2(MT1, 2), and organization-focused interventions(OTs). Effect sizes were calculated for the 4 outcome categories across intervention types: psycho-social outcome, behavioral-personal resources, physiologic, and organizational outcome. Results : Individual worker-focused interventions(ITs) were more effective than OTs. A small but significant overall effect was found A moderate effect was found for RT, and small effects were found for other ITs, The effect size for OTs was the smallest. The interventions involving CBT and RT appeared to be the preferred means of reducing worker's psycho-social and organizational outcomes. With regard to physiologic outcomes, RT appeared to be most effective. CBT appeared to be most effective in reducing psycho-social outcomes. The effects of OT were non-significant, except for the psycho-social outcomes. Conclusions: SMIs are effective. Interventions involving RT and CBT are more effective than other types.

• 한국농공학회지
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• 제45권4호
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• pp.126-136
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• 2003

The B value on the saturated soil is commonly known as the amount of 1. Usually this concept is consistent with the condition that effective stress is equal to zero, but it was reported in some literatures that the B value was less than 1 in spite of saturated condition in the test of very stiff material such as rock and quasi-stiff material on which the stiffness can be mobilized because of effective stress not equal to zero. In this study the B value was measured on various effective stress conditions on normally consolidated clay. The test results in the B value less than 1 in spite of perfect saturation. The measured excessive pore water pressure was not only smaller than the change of the total stress, but also the function of time on clay.

• 한국농공학회논문집
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• 제47권4호
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• pp.43-52
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• 2005

It is known in some literatures that the B value is not equal to unity in saturated soil when effective stress is given, in which the B Value is the ratio of measured excess pore water pressure and isometric loading pressure. In this study the B value was measured on various effective stresses and on various incremental loading stresses in various grain size of specimens with saturated sand. The test results showed that the B value was affected largely by grain size of sand in specimen and the amount of effective stress. There was the semi-logarithmic relationship between B value and effective stress, and also there was the linear relationship between the gradient of the former semi-logarithmic relationship and grain size of specimen.

• 대한치과보철학회지
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• 제41권5호
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• pp.617-625
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• 2003

Statement of problem : There are many studies focused on the effect of shape of futures on stress distribution in the mandibular bone. However, there are no studies focused on the effect of the abutment types on stress distribution in mandibular bone. Purpose : The purpose of this study is to investigate the effect of three different abutment types on the stress distributions in the mandibular bone due to various loads by performing finite element analysis. Material and method : Three different implant systems produced by Warantec (Seoul, Korea), were modeled to study the effect of abutment types on the stress distribution in the mandibular bone. The three implant systems are classified into oneplant (Oneplant, OP-TH-S11.5). internal implant (Inplant, IO-S11.5) and external implant (Hexplant, EH-S11.5). All abutments were made of titanium grade ELI. and all fixtures were made of titanium grade IV. The mandibular bone used in this study is constituted of compact and spongeous bone assumed to be homogeneous, isotropic and linearly elastic. A comparative study of stress distributions in the mandibular bone with three different types of abutment was conducted. Results : It was found that the types of abutments have significant influence on the stress distribution in the mandibular bone. It was due to difference in the load transfer mechanism and the size of contact area between abutment and fixture. Also the maximum effective stress in the mandibular bone was increased with the increase of inclination angle of load. Conclusion : It was concluded that the maximum effective stress in the bone by the internal implant was the lowest among the maximum effective stresses by other two types.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.150-154
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• 2008

In this research, stress components and principal stresses of O-ring under internal pressure and under uniform squeeze rate were obtained from the stress freezing method of photoelastic experiment and photoelastic experimental Hybrid method for 3-dimensional problems. The obtaining processes of those were introduced. It was certified that the processes of those are effective for the 3-dimensional stress analysis of structures. Stress freezing method, the obtaining processes of those and photoelastic experimental hybrid method were effectively applied to the stress analysis of O-ring made from rubber that under uniform deformation and internal pressure. Stress components and principal stress of Oring under uniform squeeze rate and under internal pressure were analyzed.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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• pp.245-251
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• 1999

As the crack grows in the residual stress fields, the distribution of the residual stress is changed. In this study, a finite element modeling technique is developed to simulate the redistribution of residual stress due to crack propagation. To certify the accuracy, the crack propagation tests were carried out and tile effective stress intensity factor range was evaluated considering the redistribution of residual stress from the FE analysis.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 춘계학술대회 논문집
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• pp.152-162
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• 2001

Comparison of results from two different methods of soil-structure dynamic interaction analysis is presented. Two methods include transfromed static and seismic response analyes. In seismic response analysis, the difference in result of total stress analysis relative to effective stress analysis is investigated.

• 여성건강간호학회지
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• 제21권3호
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• pp.232-240
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• 2015

Purpose: The purpose of this descriptive survey study was designed to identify the stress coping types of married immigrant pregnant women and find out the differences in maternal-fetal attachment and maternal identity based on each types. Methods: 151 married immigrant women who visited 3 women's hospitals located in J-do for pre-pregnancy checkup were selected as study objects. Data were analyzed by dsecriptive statistics, cluster analysis, t-test, ANOVA, and $Scheff{\acute{e}}$ multiple comparison test. Results: Cluster analysis revealed 4 distinct stress coping styles; low stress-coping involvement social support-oriented type, high stress-coping involvement hopeful thinking type, low stress-coping involvement type, effective stress coping types. Women frequently using effective stress coping type among the four types reported higher maternal-fetal attachment. The group of active coping styles got significantly higher score on maternal identity. Conclusion: Proper stress coping of married immigrant pregnant women regarding pregnancies proved to result in high levels of maternal-fetal attachment and maternal identity. Studies measuring the stress coping styles that affect pregnancies should be continuously conducted.

• International Journal of Automotive Technology
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• 제5권1호
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• pp.55-59
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• 2004

Spot welding is a very important and useful technology in fabrication of thin sheet structures such as the parts in an automobile. However, because the fatigue strength of the spot welding point is considerably lower than that of the base metal due to stress concentration at the nugget edge, the nugget size must be estimated to evaluate a reasonable fatigue strength at a spot welded lap joint. So far, many investigators have experimentally studied the estimation of fatigue strengths of various spot weldments by using a destructive method. However, these destructive methods poses problems so testing of weldments by these methods are difficult. Furthermore, these methods cannot be applied to a real product, and are time and cost consuming, as well. Therefore, there has been a strong, continual demand for the development of a nondestructive method for estimating nugget size. In this study, the effective nugget size in spot weldments have been analyzed by using thermoelastic stress analysis adopting infrared thermography. Using the results of the temperature distribution obtained by analysis of the infared stress due to adiabatic heat expansion under sinusoidal wave stresses, the effective nugget size in spot welded specimens were estimated. To examine the evaluated effective nugget size in spot weldments, it was compared with the results of microstructure observation from a 5％ Nital etching test.