• 한국자연치유학회지
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• 제10권1호
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• pp.33-41
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• 2021

목적: 숲속의 산림욕은 인체의 스트레스 개선에 효과가 있는지를 연구하였다. 제주 삼다수 숲길을 2시간 동안 걸어서 산림욕을 한 후에 맥박과 스트레스 지수의 변화, 자율신경의 변화를 조사하는 것이었다. 방법: 연구는 산림욕 전후에 심장박동 변이와 설문을 통한 조사를 하였다. 결과: 산림욕 후 실험군의 평균 맥박은 유의하게 증가하였다. 스트레스 지수는 실험군에서는 사후에 유의하게 감소하였다. 누적 스트레스, 교감신경 활성(LF), 부교감신경 활성도(HF) 변화 및 LF/HF 비율은 실험군에서는 사후의 측정치의 차이는 있으나, 통계적으로 유의성이 없었다. 설문을 통한 직무 스트레스 평균 지수와 상태 특성 불안 지수의 조사에서는 사후에 유의하게 감소하였다(p<.001). 결론: 삼다수 산림욕이 맥박을 증진하고 스트레스를 감소하는 효과가 입증되어 산림욕이 건강증진에 효과적이라 평가한다.

• Animal Bioscience
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• 제37권1호
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• pp.16-27
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• 2024

Objective: The objective of this study was to investigate the effect of heat stress on the growth traits and genetic parameters of Thai native chickens. Methods: A total of 16,487 records for growth traits of Thai native chickens between 2017 and 2022 were used in this study. Data included the body weight at birth, body weight at 4, 8, and 12 weeks of age (BW0, BW4, BW8, BW12), average daily gain during 0 to 4, 4 to 8, and 8 to 12 weeks of age (ADG0-4, ADG4-8, ADG8-12), absolute growth rate at birth, at 4, 8, and 12 weeks of age (AGR0, AGR4, AGR8, AGR12). The repeatability test day model used the reaction-norm procedure to analyze the threshold point of heat stress, rate of decline of growth traits, and genetic parameters. Results: At temperature and humidity index (THI) of 76, Thai native chickens began to lose their growth traits, which was the onset of heat stress in this study. The estimated heritability, genetic correlation between animal and heat stress effect, and correlations between the intercept and slope of the permanent environmental effects were 0.27, -0.85, and -0.83 for BW, 0.17, -0.81, and -0.95 for ADG, 0.25, -0.61, and -0.83 for AGR, respectively. Male chickens are more affected by heat stress than female chickens with a greater reduction of BW, ADG, and AGR, values equal to -9.30, -0.23, -15.21 (in males) and -6.04, -0.21, -10.10 (in females) gram per 1 level increase of THI from the THI of 76. Conclusion: The influence of thermal stress had a strong effect on the decline in growth traits and genetic parameters in Thai native chickens. This study indicated that genetic models used in conjunction with THI data are an effective method for the analysis and assessment of the effects of heat stress on the growth traits and genetics of native chickens.

• 한국생산제조학회지
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• 제21권4호
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• pp.672-676
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• 2012

This paper studies the relation between the deformation of platen caused by clamping force, the bending stress and elongation at the tie-bar in injection molding machine of toggle type. These data are analyzed through analytical molding and numerical approach by tensile tester. The effect of bending stress on the stress concentration of teeth and nut system is also analyzed by 2 dimensional numerical approach. The bending stress of tie-bar caused by platen deformation becomes less than 20% of average tensile stress. And the effect of bending stress on stress concentration at teeth and nut system of tie-bar is found to be small.

• 한국간호교육학회지
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• 제12권2호
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• pp.238-247
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• 2006

The purpose of this study is to investigate the relationship between nurslng students' self-differentiation, their stress level and stress coping strategies. And following research questions were established. First, what is the difference of the stress level depending on the self-differentiation? Second, what is the difference of stress coping strategies in accordance with the self-differentiation? Participants for this study were 159 students selected from the 1st grades of G University, located in Incheon Metropolitan city. SPSS 10.0 statistic program was taken for drawing its frequency, percentage, average and standard deviation. And t-test, F-test, correlation and multiple regression were conducted. The results are summarized as follows: 1. The mean score for the level of self- differentiation, level of stress, level of stress coping strategies were 3.59, 2.50, 3.35. 2. The relationship between self-differentiation and stress level revealed a negative significant correlation 3. The relationship between self-differentiation and stress coping strategies revealed a no significant correlation. 4. The relationship between stress level and stress coping strategies revealed a no significant correlation. Conclusion: The results of investigating the variation differences depending on stress level, self-differentiation, and stress coping strategies were revealed self-differentiation and stress coping strategies explained stress level by 28.6%.

• 한국임상수의학회지
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• 제22권2호
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• pp.136-140
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• 2005

This experiment is designed to determine the relationship between groomers' activities and stress. The experimenter worked with 2 female dogs and 3 male dogs owned by clients. They were 22 months old on an average and weighed 5.5kg on an average. The concentration of cortisol in blood was measured with radioimmunoassy(RIA). The concentration of cortisol in blood was high in the morning and evening and was low in the afternoon. In a normal condition, the concentration of cortisol in blood was $1.4{\mu}g/dL$, which increased to $4.98{\mu}g/dL$ after 1 hr of grooming, and then returned to normal at the termination of grooming. The survey shows that grooming acted as a stressor, which seems to have an influence on the health of dogs. So it is absolutely necessary that systematic and constant research should be conducted to reduce stress at the time of grooming.

• Computers and Concrete
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• 제26권6호
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• pp.515-531
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• 2020

Due to the construction difficulties of steel reinforced concrete (SRC), a new composite structure of steel and steel fiber reinforced concrete (SSFRC) is proposed for solving construction problems of SRC. This paper aims to investigate the bond properties and composition of interfacial bond stress between steel and steel fiber reinforced concrete. Considering the design parameters of section type, steel fiber ratio, interface embedded length and concrete cover thickness, a total of 36 specimens were fabricated. The bond properties of specimens were studied, and three different methods of calculating interfacial bond stress were analyzed. The results show: relative slip first occurs at the free end; Bearing capacity of specimens increases with the increase of interface embedded length. While the larger interface embedded length is, the smaller the average bond strength is. The average bond strength increases with the increase of concrete cover thickness and steel fiber ratio. And calculation method 3 proposed in this paper can not only reasonably explain the hardening stage after the loading end curve yielding, but also can be applied to steel reinforced high-strength concrete (SRHC) and steel reinforced recycled coarse aggregate concrete (SRRAC).

• 동의생리병리학회지
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• 제36권2호
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• pp.54-58
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• 2022

This study aimed to investigate the anti-stress function of Aucklandiae Radix (AR) and Cyperi Rhizoma (CR). The essential oils used in the experiment were extracted from AR and CR using Steam Distillation Extraction and Super critical CO₂ extraction. To observe the effects of sample administration, we measured feed intake, leukocytes, red blood cells, hemoglobin, platelets, serum serotonin content, immobility time, climbing time, and swimming time in mice subjected to chronic restraint stress as behavioral changes. The average body weight of all experimental groups increased than the average body weight of the control group. The immobility and climbing times of experimental groups A and B administered with supercritical extraction samples were shorter than those of the other experimental groups and the control group, and the swimming time was longer. The serotonin content in the blood of all experimental groups decreased compared to the normal group, and the serotonin content of the control group was increased. The authors suggest that Korean herbal medicines AR and CR may be utilized as anti-stress flavoring agents based on the above results.

• 한국기계연구소 소보
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• 통권15호
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• pp.91-103
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• 1985

In this paper, temperature distribution and thermal stress are investigated considering engine peak pressure and the time average temperature distribution in the piston under running conditions for the diesel engine. The induced stress are calculated by the Finite Element Method(FEM). The results obtained are summerized as follows. 1) The results calculated by the FEM present good agreement with other numerical solution in literature. 2) It is confirmed that maximum compressive stress are induced in the part of outside wall between the piston crown and the pin bush. 3) In the axial direction, the hoop stresses are changed its sigh at the portion of crown near the inner wall side 4)Large gradient of temperature is shown in the piston crown near the side wall in the axial direction, in the part between the piton crown and the pin bush in radical direction 5)in case of stress distribution of piston wall surface in the axial direction, the hoop stress is a little greater than axial stress, and the latter is greater than the radial stress

• 한국산업융합학회 논문집
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• 제21권2호
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• pp.79-86
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• 2018

The purpose of this study is to compare life stress between primigravida and multigravida in advanced maternal age. A cross-sectional study was performed for 133 pregnancy women (primigravida group 53, multigravida group 80). The all women were old age (${\geq}35years$) and pregnant. We used the questionnaire to self-report general characteristics, obstetric characteristics and life stress. The average of participants age was 36.15 years old, primigravida was 36.08 and multigravida was 36.19. The mean of total life stress score was 2.68 and the total life score for pregnant women of lower education level was higher. The marital relationship of primigravida was lower than multigravida(mean, .06 vs. .26; p=.021). As our study shows that stress of marital relationship is higher in the multigravida than primigravida, the life stress care for advanced maternal age is important.

• Journal of Advanced Marine Engineering and Technology
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• 제9권2호
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• pp.143-152
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• 1985

In this paper, temperature distribution and thermal stress are investigated considering engine peak pressure and the time average temperature distribution in the piston under running conditions for the marine diesel engine. The induced stress are calculated by the Finite Element Method (FEM). The results obtained are summerized as follows. 1) The results calculated by the FEM present good agreement with other numerical solution in literatures. 2) It is comfirmed that the maximum compressive stresses are induced in the part of outside wall between the piston crown and the pin bush 3) In the axial direction, the hoop stresses are changed its sign at the portion of crown near the inner wall side. 4) Large gradient of temperature is shown in the piston crown near the side wall in the axial direction, in the part between the piston crown and the pin bush in radial direction. 5) In case of stress distribution of piston wall surface in the axial direction, the hoop stress is a little greater than axial stress, and the latter is greater than the radial stress.