• 한국산학기술학회논문지
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• 제12권11호
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• pp.4819-4825
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• 2011

이 연구는 노인들의 성격유형이 스트레스 저항에 미치는 영향이 있는지를 개인이 지닌 뇌신경 생리학적 지표인 뇌파 측정을 이용하여 비교하여 보았다. 대상자는 한국정신과학연구소에 2007년 9월에서 2010년 12월까지 뇌파측정을 실시한 노인(만 65세 이상)들을 기준으로 선정한 자료이며, 총 1108명이다. 행동성향의 분포도는 긍정 적극성향이 552명, 부정 소극성향이 556명이었으며, 정서성향의 분포도는 명랑(외향)성향이 735명, 우울(내향)성향이 373명이었다. 분석 결과 노인들의 행동성향과 스트레스 저항과는 무관하였으며, 정서성향과 스트레스 저항과는 (p=.000)으로 유의미한 차이가 있었다. 즉, 명랑(외향)성향이 우울(내향)성향에 비하여 항 스트레스지수에서 평균이 높게 차이가 났으며, 이는 스트레스를 이겨낼 수 있는 능력이 높다고 할 수 있겠다. 이 연구 결과 정서성향과 스트레스 저항능력이 관련이 있음을 보여주었으며 미치는 영향이나 작용기전을 규명하는 연구가 필요하다고 사료된다.

• 한국지반환경공학회 논문집
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• 제14권10호
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• pp.17-27
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• 2013

This paper explores stress release induced by unloading in dry sand. A series of model tests were carried out to measure stresses developed in testing sand during loading and those released during unloading for different boundary conditions. It was found that stress in the sand increased linearly with applied load. At the onset of unloading, almost no stress release was observed. Significant stress release took place when the shear stress in the sand induced by unloading exceeded the frictional resistance and caused movement of sand particles. The initiation and the magnitude of stress release depend on the stress condition prior to unloading, the decrease of external load, and also the frictional resistance in sand. A new conceptual stress-release model was next developed based on the model test results by considering the fundamental frictional behavior of granular materials.

• The Plant Pathology Journal
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• 제35권5호
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• pp.393-405
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• 2019

Survival factor 1 (Svf1) is a protein involved in cell survival pathways. In Saccharomyces cerevisiae, Svf1 is required for the diauxic growth shift and survival under stress conditions. In this study, we characterized the role of FgSvf1, the Svf1 homolog in the homothallic ascomycete fungus Fusarium graminearum. In the FgSvf1 deletion mutant, conidial germination was delayed, vegetative growth was reduced, and pathogenicity was completely abolished. Although the FgSvf1 deletion mutant produced perithecia, the normal maturation of ascospore was dismissed in deletion mutant. The FgSvf1 deletion mutant also showed reduced resistance to osmotic, fungicide, and cold stress and reduced sensitivity to oxidative stress when compared to the wild-type strain. In addition, we showed that FgSvf1 affects glycolysis, which results in the abnormal vegetative growth in the FgSvf1 deletion mutant. Further, intracellular reactive oxygen species (ROS) accumulated in the FgSvf1 deletion mutant, and this accumulated ROS might be related to the reduced sensitivity to oxidative stress and the reduced resistance to cold stress and fungicide stress. Overall, understanding the role of FgSvf1 in F. graminearum provides a new target to control F. graminearum infections in fields.

• 대한기계학회논문집A
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• 제29권9호
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• pp.1225-1234
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• 2005

Mode I stress intensity factor $(K_I)$ of Notched Ring Test(NRT) specimen for measuring slow crack growth resistance was found using finite-element method. The theoretical $K_I$ value of NRT was not available in any references and could not be solved analytically. At first, in order to verify the accuracy of the finite-element approach, published $K_I$ values of several cracks were calculated and compared with finite-element results. The results were in good agreement within inherent errors of theoretical $K_I$. Finally the mode I stress intensity factor of NRT was found using 2- and 3-dimensional finite-element methods and expressed as a function of the applied load. This enabled direct comparison of resistance to slow crack growth between NRT and Notched Pipe Test(NPT), which employ different loading regime.

• 한국지반공학회논문집
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• 제20권9호
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• pp.33-45
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• 2004

모래를 사용해서 매립하는 경우 일반적으로 한 가지 이상의 포설방법으로 매립이 수행된다. 따라서 모래매립지반은 그 특성이 층별로 다양하게 형성되며, 이러한 지반특성을 파악하기 위해서 일반적으로 콘관입시험이 널리 이용되고 있다. 콘저항값은 임의의 깊이에서 현장의 응력수준, 즉 상재하중의 크기에 따라 영향을 많이 받기 때문에 콘저항값을 현장의 응력수준으로 정규화할 필요가 있다. 그러므로 현장응력수준으로 정규화된 콘저항값을 이용하여 신뢰할 수 있는 지반정수와의 상관관계식을 도출하는 것이 바람직하다. 본 연구에서는 응력에 대해 최적으로 정규화된 콘저항값을 이용하여 더욱 합리적인 지반정수를 도출하고자, 싱가폴 창이 동부 매립현장에 위치한 l0m 높이의 여성토를 약 2 m씩 단계적으로 제거하며, 각 단계마다 콘관입시험을 실시하였다. 여기서 측정된 콘저항값을 다양한 방법으로 응력정규화하여 그 값들을 비교함으로써 최적의 정규화 방법을 제안하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.145-146
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• 2023

In this study, the effect of hybrid fiber reinforcement on the residual strength and impact resistance of high-strength cementitious composites exposed to high temperatures was investigated. A cementitious composites was manufactured in which 0.15 vol% of polypropylene fiber (PP) and 1.0 vol% of smooth steel fiber (SSF) were double-mixed, and a residual strength test was conducted while thermal stress was applied by heating test, and then a high-velocity impact test was performed. In the case of general cementitious composites, the rear surface is damaged due to explosion and low tensile strength during high temperature or impact, while hybrid fiber reinforced cementitious composites can repeatedly absorb and distribute stress until multiple fibers are damaged to suppress the propagation of impact and resistance to explosion. Therefore, this study analyzed the residual strength of cementitious composites exposed to high temperatures depending on whether hybrid fibers were mixed or not, and collected research data on fracture behavior through high-speed impact tests to evaluate impact resistance and mechanical properties.

• 대한예방한의학회지
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• 제11권1호
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• pp.109-129
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• 2007

This study aims at grasping the relativity between laborers' yangseng level and stress so as to present the groundwork for preventive oriental medicine approach in industrial health. The researcher prepared the questionnaire on general character, health-related yangseng level and chose 632 people to execute Autonomic balance test through heartbeat change. The collected material was analyzed by SPSS and tested by T-test, ANOVA. The general yangseng level average is 3.27, morality yangseng 3.91, sleep yangseng 3.39, mind yangseng 3.32, sex life yangseng 3.29, exercise yangseng 3.14, activities and rest yangseng 3.07, diet yangseng 2.95, seasonal yangseng 2.84. The highest is morality yangseng and seasonal yangseng is the lowest. In the aspect of yangseng level : Having a spouse, Non-smoking, Non-drinking, Regular exercising, Sufficient sleeping have higher yanseng levels. In Autonomic balance test, age from 35 to 40 has the highest autonomic activity and job period from 5 years to 10 years has the highest stress resistance. Non-smokers have high autonomic activity and stress resistance. Further, have low autonomic balance, stress index and fatigue strength. In the case of regular exercising person, he/she has high autonomic activity and stress resistance with low stress index. Regarding sleeping time, autonomic balance is the highest when he/she sleeps less than 6 hours. Stress resistance is the highest when he/she sleeps 7 hours and stress index is the highest when he/she sleeps 6 hours. After comparing the relativity between yangseng level autonomic balance test, only exercise yangseng has plus factor on autonomic activity and stress resistance and minus factor on stress ind ex and fatigue strength. Yangseng level has been affected by individual character and daily habits. Also stress is more influenced by daily habits than by individual character. We can find the relativity of exercise yangseng between yangseng and stress which suggests that we need to take measures to win over stress in individual health in the near future.

• Journal of Plant Biotechnology
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• 제40권1호
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• pp.49-54
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• 2013

C3HC4-type RING zinc finger proteins essential in the regulation of plant processes, including responses to abiotic stresses. We previously isolated and examined the C3HC4-type RING zinc finger protein (BrRZFP1) from Brassica rapa under abiotic stresses. To elucidate the role of the BrRZFP1 transcription factor in gene regulation, we transformed tobacco plants with the BrRZFP1 gene. Plants were regenerated from 82 independently transformed callus lines of tobacco and analysed for transgene expression. Transgene integration and expression was confirmed by Southern and RT-PCR analyses, respectively. T2 plants displayed more tolerance to the bacterial pathogens Pectobacterium carotovorum and Ralstonia solanacearum, and the tolerance levels were correlated with BrRZFP1 expression levels. These results suggest that the transcription factor BrRZFP1 is an important determinant of stress response in plants and its overexpression in plants could increase biotic stress resistance.

• 대한의료기공학회지
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• 제10권1호
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• pp.100-129
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• 2007

This study aims at grasping the relativity between laborers' yangseng level and stress so as to present the groundwork for preventive oriental medicine approach in industrial health. The researcher prepared the questionnaire on general character, - health-related yangseng level and chose 632 people to execute Autonomic balance test through heartbeat change. The collected material was analyzed by SPSS and tested by T-test, ANOVA The general yangseng level average is 3.27, morality yangseng 3.91, sleep yangseng 3.39, mind yangseng 3.32, sex life yangseng 3.29, exercise yangseng 3.14, activities and rest yangseng 3.07, diet yangseng 2.95, seasonal yangseng 2.84. The highest is morality yangseng and seasonal yangseng is the lowest. In the aspect of yangseng level: Having a spouse, Non-smoking, Non-drinking, Regular exercising, Sufficient sleeping have higher yangseng levels. In Autonomic balance test, age from 35 to 40 has the highest autonomic activity and job period from 5 years to 10 years has the highest stress resistance. Non-smokers have high autonomic activity and stress resistance. Further, have low autonomic balance, stress index and fatigue strength. In the case of regular exercising person, he/she has high autonomic activity and stress resistance with low stress index. Regarding sleeping time, autonomic balance is the highest when he/she sleeps less than 6 hours. Stress resistance is the highest when he/she sleeps 7 hours and stress index is the highest when he/she sleeps 6 hours. After comparing the relativity between yangseng level autonomic balance test, only exercise yangseng has plus factor on autonomic activity and stress resistance and minus factor on stress index and fatigue strength. Yangseng level has been affected by individual character and daily habits. Also stress is more influenced by daily habits than by individual character. We can find the relativity of exercise yangseng between yangseng and stress which suggests that we need to take measures to win over stresses in individual health in the near future.

• 대한기계학회논문집
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• 제18권12호
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• pp.3227-3235
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• 1994

This paper deals with an evaluation of the residual stress due to shot peening induced in a carburized gear tooth and its application to the fatigue crack propagation problem. A practical method is proposed on the basis of the assumption that the residual stress is caused by the difference of volume expansion in the case and the core, and the influence of both the reduction of retained austenite and the strain due to shot peening are considered. The evaluated residual stress is close to the measured stress, though the surface stress is rather overestimated. The stress intensity factor is computed by the influence function method, and it is shown that the factor is decreased by the residual stress in shot peened gear tooth. The shot peening is fairly effective to the reduction of fatigue crack growth rate. The crack propagation is simulated and the resistance due to shot peening is quantitatively demonstrated and discussed.