• 한국자동차공학회논문집
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• 제13권5호
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• pp.104-111
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• 2005

With increasing use of SUH35/SUH3 dissimilar materials for automotive engine valves, it is required that stress singularities under residual stress on an interface for friction welded dissimilar materials analyzed to establish strength evaluation. The stress singularity $index{\lambda}$ and stress singularities $factor{\Gamma}$ were calculated from using the results of stress analysis to consider residual stress and loads. The stress singularities on variations for shapes and thickness of welded flashes were analyzed and discussed. This paper suggested that the strength evaluation by using the stress singularity factors as fracture parameters, considering the stress singularity on an interface edge of friction welded dissimilar materials will be useful.

• Food Science and Biotechnology
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• 제18권1호
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• pp.25-30
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• 2009

The anti-stress effects of kimchi were studied in the Sprague-Dawley rats dosed with kimchi. The rats in the stress groups were subjected to immobilization stress for 2 hr/day for 5 days. At the end of the experimental period, daily average food intake and body weight (BW) gain had been reduced in the stress group compared to the control group. Daily average food intake was significantly increased in the stress-kimchi diet group compared to the stress-only group. The weights of the thymus and spleen were decreased by immobilization stress, but this reduction was partially suppressed by the addition of kimchi. The weights of the adrenal gland and epididymal adipose tissue were increased in the stress group, but ingestion of kimchi completely and partially suppressed these stress-induced changes, respectively. Serum levels of total cholesterol and triglyceride, and plasma levels of corticosterone were increased in the stress group, but at control levels in the stress-kimchi diet group.

• Structural Engineering and Mechanics
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• 제55권4호
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• pp.885-900
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• 2015

This paper introduces Romberg-Richardson's method as one of the numerical integration tools for computation of stress intensity factor in a pre-cracked specimen subjected to a complex stress field across the crack faces. Also, the computation of stress intensity factor for various stress fields using existing three methods: average stress over interval method, piecewise linear stress method, piecewise quadratic method are modified by using Richardson extrapolation method. The direct integration method is used as reference for constant and linear stress distribution across the crack faces while Gauss-Chebyshev method is used as reference for nonlinear distribution of stress across the crack faces in order to obtain the stress intensity factor. It is found that modified methods (average stress over intervals-Richardson method, piecewise linear stress-Richardson method, piecewise quadratic-Richardson method) yield more accurate results after a few numbers of iterations than those obtained using these methods in their original form. Romberg-Richardson's method is proven to be more efficient and accurate than Gauss-Chebyshev method for complex stress field.

• 대한간호학회지
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• 제16권1호
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• pp.40-48
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• 1986

The purpose of this study was to identify the effect of the Stress Management Education Program (SMEP) on the nurses stress and stress management ability, and to identify the main factors affecting them. The subjects were 72 nurses who participated in the In-Service education program of the Jin-Ju District, Kyeong-Nam Branch of the Korean Nurses Association during the period from Oct. 1 to Nov. 30, 1985. The book of“The stress management education program”was developed by the investigators. With this book, we executed the 1st education through the lecture & showing an example, After 15 days from the 1st education, we mailed a reminding booklet to the individuals. (2nd education). Then, we mailed a questionnaire on 15th day from the 2nd education. Before and after the SMEP We measured the stress management ability & stress, and identified the affecting factors. Findings of this study are as follows ; 1. The 1st hypothesis that“the SMP will increase the. knowledge about the nurses' stress management”was supported (t= -6.60, p <.001) 2. The 2nd hypothesis that“the SMEP will increase the nurses' practice about the stress management”was rejected. 3. The 3rd hypothesis that“the SEMP will decrease the nurses' stress”was rejected. 4. The 4th hypothesis that“the higher the know-ledge about the stress management, the lower the nurses' stress”was rejected. 5. The 5th hypothesis that“the higher the degree of the practice about the stress management, the lower the nurses' stress”was supported. (r= - .2859, p<.05). 6. There were significant correlations between the knowledge about stress management and age (r= -.3717, p<.01), between the knowledge about stress management and the period of her work. (r= -.2897, p<0.5). There was significant difference in the knowledge about stress management between those who had married and those who had not. (t=2.82, p<.01) 7. There was significant difference in the practice about the stress management between those who had religion and those who had not. (t=2.7, p< .01) 8. There was significant difference in the stress according to the type or work. (t=6. 127, P <.05) There was significant correlation between the stress and supportive system. (r=-.2647, p<.05).

• 대한한방부인과학회지
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• 제19권4호
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• pp.93-116
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• 2006

Purpose : This study is to examine the effects of Hwaganjeon water extract(HGJ) on immobilization-stress or cold-stress in BALB/C mice. Methods : We have Hwaganjeon water extract(HGJ) by freeze-dryer & melt it by a saline solution. We feed HGJ 500mg/Kg to 5mice, and add immobilization-stress by putting mice in plastic cylinder 10 hours, and add cold-stress by putting mice in $4^{\circ}C$ cold room 6 hours. Results : 1. HGJ decreased the serum level of histamine and corticosterone increased by immobilization-stress or cold-stress. HGJ inhibited the release of histamine from mast cells at the concentration of 1 mg/ml. 2. HGJ did not affect the cell viability of thymocytes decreased by immobilization-stress or cold-stress, but increased the cell viability of splenocytes decreased by immobilization-stress or cold-stress. 3. HGJ decreased the population of splenic $CD4^{+}$ and $CD8^{+}$cells increased by immobolization-stress or cold-stress. 4. HGJ enhanced the production of ${\gamma}$-interferon(IFN) and interleukin(IL)-2 decreased by immobilization-stress or cold-stress. Conclusion : These results indicate that HGJ may be useful for the prevention and treatment of stress via suppression of serum histamine and corticosterone level and enhancement of immune response.

• 농업과학연구
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• 제45권1호
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• pp.58-65
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• 2018

Meat quality includes technological quality attributes, consumer acceptance, and credence characteristics. In terms of credence characteristics, animal welfare is one of the most interesting topics to both consumers and the livestock industry. Consumers prefer meat produced from livestock that has been raised in low stress and ecofriendly environments. The livestock industry cares about animal welfare to meet the requirements of consumers. Animal welfare is closely associated with the stress and physiological response of livestock to stress. Moreover, stress just before slaughter (i.e., pre-slaughter stress) has negative effects on not only animal welfare but also ultimately on meat quality. It is well-documented that pre-slaughter stress can influence ante- and post-mortem biological changes of the muscles, especially their metabolic properties and metabolites. The metabolic properties and metabolites contents also can modulate the postmortem changes of the muscles. Conversion of muscles to meat during postmortem is a very important process because it determines ultimately the meat quality. Thus, understanding pre-slaughter stress and physiological responses to stress in farm animals is important for animal welfare and meat quality. The purpose of this paper was to examine the concept of stress, physiological responses to stress, measurement of stress, and the relationships between stress indices and meat quality traits.

• Computers and Concrete
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• 제17권2호
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• pp.173-188
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• 2016

Generally, thermal stress induced by hydration heat causes cracking in mass concrete structures, requiring a thorough control during the construction. The prediction of the thermal stress is currently undertaken by means of numerical analysis despite its lack of reliability due to the properties of concrete varying over time. In this paper, a method for the prediction of thermal stress in concrete structures by adjusting thermal stress measured by a thermal stress device according to the degree of restraint is proposed to improve the prediction accuracy. The ratio of stress in concrete structures to stress under complete restraint is used as the degree of restraint. To consider the history of the degree of restraint, incremental stress is predicted by comparing the degree of restraint and the incremental stress obtained by the thermal stress device. Furthermore, the thermal stresses of wall and foundation predicted by the proposed method are compared to those obtained by numerical analysis. The thermal stresses obtained by the proposed method are similar to those obtained by the analysis for structures with internally as well as externally strong restraint. It is therefore concluded that the prediction of thermal stress for concrete structures with various boundary conditions using the proposed method is suggested to be accurate.

• 전산구조공학
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• 제8권1호
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• pp.137-146
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• 1995

본 논문에서는 최근 관심이 증대되고 있는 충격하중에 의해 시간의 흐름에 따라 형성되는 구조물의 응력분포 양상을 유한요소 해석적으로 고찰하기 위하여 동적 응력 해석 프로그램을 개발하였다. 유한요소 해석에 의하면, 종방향 응력파는 충격하중이 작용하는 방향과 동일한 방향으로 진행하며, 응력파 선단의 속도와 모양은 이론해석에 의한 결과와 같음을 알 수 있다. 또한 종파의 진행방향에 45.deg. 방향으로 전단파가 발생하여 진행함을 알 수 있으며, 전단파의 속도는 종파의 1/2이 되고, 종파보다 전단파의 강도가 큼을 알 수 있다.

• 음성과학
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• 제10권2호
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• pp.303-318
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• 2003

This paper attempts to investigate the tonal implementations of English stress clash, arguing that a preceding stress shifts leftward when two lexical stresses conflict across word boundaries or that H* and L* pitch accents are alternatively manifested on the stressed syllables, establishing intonational peak and valley contours. We claim that the H*/L* alternation might be a tonal strategy to avoid stress clash, and that pitch could be solely manipulated to display a rhythmic effect with maintaining lexical stress. In the experiment, we examined two-word combinations whose boundaries involve stress clash, and divided them into two categories. One has the preceding words involving a heavy syllable ahead of stress to guarantee the place for a shifting stress and the other, a light syllable, in which case stress shift is completely prevented. We analyzed the distribution of pitch accents in the word combinations, focusing on the pitch configurations in the cases where stress should not be shifted. Results show that approximately 50% of the stimuli show stress shift in the heavy syllable combinations of the preceding words; the preceding stress is moved leftward within the word. The other 50% and the light syllable combinations show various pitch accents patterns; H* and L* alternation, deaccentuation of either stressed syllable, or L-insertion between two H* pitch accents, etc. We interpret this as a rhythmic effect of tone to avoid stress clash and suggest that a true stress clash would be confined into cases without H*/L* contours.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.431-438
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• 2005

In this paper, the characteristics of excessive horizontal stress components in Korea were studied using the in-situ hydraulic fracturing stress measurement data over five hundred in 110 individual test boreholes. Based on the in-situ testing data, the magnitude and orientation of the horizontal stress component and variation of stress ratio (K) with depth were investigated. And also horizontal stress magnitude versus depth relationships and distribution limits of stress ratio components were suggested. For the subsurface space above 310 m depth in the entire territory, the stress ratio has a tendency to diminish and be stabilized with depth, but for some areas, it was revealed that the excessive horizontal stress fields with stress ratio close to 3.0 below 200 m in depth have formed. The result of investigation for excessive horizontal stress regions indicates that there exist several regions above 300 m in depth where localized excessive horizontal stresses enough to induce potentially brittle failure around future openings have formed.