• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.821-825
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• 2007

In this study, the single hardening model with stress history-dependent plastic potential, which has been most recently proposed based on the critical state soil mechanics and needs few model parameters, was verified for the normally, lightly, and heavily over-consolidated clayey specimens. The triaxial compression tests were strictly conducted. The predictions using the single hardening model generally agree with the measurement. The discrepancy exists on its main focusing on the principal stress rotation; however, the plastic work H and the principal stress rotation angle ${\beta}$ are found to be effective indicators of loading history for the plastic potential function of the stress path dependent materials.

• Biomedical Science Letters
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• v.25 no.3
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• pp.211-217
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• 2019

Research has established a strong connection between a diet rich in antioxidants and a decreased incidence of cardiovascular disease and cancer. These diets prominently feature fruits and vegetables containing high amounts of vitamins A, B, C and E, carotenoids, and minerals. Different processing conditions for these foods can alter their nutrient complement and potency. This study compared the antioxidant properties of a range of processed fruits and vegetables to see which yielded the highest level of antioxidant activity. We used an acetaminophen-induced oxidative stress mouse model to evaluate the antioxidant effects of extracts of processed apple, pear, carrot, cabbage, broccoli, and radish. Our results showed that the administration of these fruits decreased the expression of oxidative stress indicators such as ALT, AST, catalase, superoxide dismutase, GPx, and 8-OHdG. They also significantly protected mice livers from APAP-induced damage, as shown by histological evaluation. Our results have demonstrated the positive effects of processed fruits and vegetables in a mouse model of oxidative stress.

• Journal of Acupuncture Research
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• v.29 no.6
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• pp.47-56
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• 2012

Objectives : This study was performed to investigate the effect of acupuncture at Yintang point(EX-$HN_3$) on heart rate variability in healthy adults with mental stress. Methods : 38 healthy volunteers(sham point group : 19, Yintang point group 19) participated in this study. The study was established by randomized trial. After 10 minutes rest period, mental stress was provided for 10 minutes. HRV was recorded before and after stress. And then simple acupuncture was applied at sham or Yintang point for 15 minutes. We measured HRV 3 times: before and after stress, and after acupuncture. Results : In sham point group, LF norm and HF norm changed significantly after mental stress. In Yintang point group, LF, HF, LF norm, HF norm and LF/HF showed a significant change after mental stress. In sham point group, all indicators were not affected after acupuncture. In Yintang point group, HF norm decreased significantly. LF, LF norm and LF/HF increased significantly. There were significant differences between two groups(p<0.05). Conclusions : The results suggest that acupuncture at Yintang point(EX-$HN_3$) can regulate and prevent the alteration of autonomic nerve system by mental stress.

• Journal of Family Relations
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• v.21 no.1
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• pp.51-76
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• 2016

Objectives: This study aims to investigate the effect of marital relationship on parenting stress among dual- and single-earner families. In particular, this study focuses on the interaction effect of marital relationship and father's child-rearing involvement on the parenting stress. To access factors associated with parenting stress, we included marital satisfaction and marital conflict as the dimensions of marital relationship in this study. Method: We employed data from the 5th wave of the Panel Study of Korean Children(PSKC) data. Our analysis sample consisted of 1,515 parents having at least one child aged under 4 years. Also, this study conducted descriptive statistics and multiple regression analysis. Results: First of all, marital satisfaction and marital conflict were significantly related to parenting stress for both mother and father in dual-earner families. While both indicators were significantly related to parenting stress for father, marital conflict only was a significant predictor for mother in single-earner families. Second, father involvement was a significant predictor for parenting stress for father in both dual- and single-earner families. Third, interaction effects were found between father involvement and marital conflict in the dual-earner families and between father involvement and marital satisfaction in the single-earner families. Conclusions: Based on the results, we recommended programs designed to enhance father's child-rearing involvement such as parenting education and community-based campaign. In addition, we recommended that policy and practice need to identify marital relationship dynamics to promote father's involvement and to reduce marital conflict in both dual- and single-earner families accordingly.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.627-641
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• 2020

Intensive farming methods that do not guarantee animal welfare can induce stress in pigs. Stress, in turn, can reduce their disease resistance and influence their hormones and metabolites in such a manner that productivity is negatively affected. This study was conducted to compare the stress related factors and blood characteristics of pigs raised on conventional farms and those raised on animal welfare farms. We measured the levels of cortisol, epinephrine and norepinephrine, biochemical parameters in blood and glycogen, L-lactate and heat shock protein 70 (HSP70) in muscle, as physiological markers of indicating the stress in conventional farm pigs (Control, n=10) and animal welfare farm pigs (Welfare, n=10). We found that there was a significant difference in the albumin-globulin ratio (A/G ratio), as well as the albumin (ALB), blood urea nitrogen (BUN) and aspartate aminotransferase (AST) levels between the two farms. Epinephrine was significantly higher in conventional farm, while level of norepinephrine was higher in animal welfare farm. There was no significant difference in cortisol, which is known as a stress hormone, across the two groups of farms. Muscular glycogen content was significantly high in animal welfare farm pigs. While L-lactate tended to be low in the animal welfare farm pigs, the difference between them and the conventional farm cohorts was not significant. HSP70 showed high levels of expression in conventional farm. Thus, we suggested that blood parameter results showed a stress response in the livers of conventional farm, and that catecholamine hormones, glycogen, L-lactate and HSP70 can be used as physiological factors of assessing animal welfare.

• Nuclear Engineering and Technology
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• v.41 no.10
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• pp.1315-1322
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• 2009

The present article is concerned with the application of an electrochemical noise (EN) monitoring technique to analyze the initiation and propagation of Pb-assisted stress corrosion cracking (SCC) of an Alloy 600 material in a simulated environment of a steam generator (SG) sludge pile at high temperatures. A typical increase of electrochemical current noise (ECN) and electrochemical potential noise (EPN) was frequently recorded from the EN measurement in a caustic solution with such impurities as PbO and CuO, indicating that there are localized corrosion events occurring. With the aid of microscopic and spectral analyses, the EN data involving information on such stochastic processes as uniform corrosion and the initiation and propagation of SCC, were analyzed based on a stochastic theory.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.397-397
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• 2019

With the consequences of climate change becoming more evident, research on climate-associated risks has become a basis for climate adaptation and mitigation. Amongst the different sectors and natural resources considered in assessing such risks, drought is one impact to our environment that experiences stress from climate change but is often overlooked and has the potential to bring severe consequences when drought occurs. For example, when temperatures are higher, water demand increases and water supply decreases; when precipitation patterns fluctuate immensely, floods and droughts occur more frequently at greater magnitudes, putting stress on ecosystems. Hence, it is important for us to evaluate drought risk to observe how different climate change and socioeconomic scenarios can affect this vital life resource. In this study, we review the context of drought risk on the basis of climate change impacts and socioeconomic indicators. As underlined in the IPCC AR5 report, the risks are identified by understanding the vulnerability, exposure, and hazards of drought. This study analyzed drought risk on a global scale with different RCP scenarios projected until the year 2099 with a focus on the variables population, precipitation, water resources, and temperature.

• Geomechanics and Engineering
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• v.11 no.1
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• pp.41-58
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• 2016

This paper focuses on the deformation behavior of tunnels crossing a weak zone in conventional tunneling. A three-dimensional finite element model was adopted that allows realistic modeling of the tunnel excavation and the support installation. Using the 3D FE model, a parametric study was conducted on a number of tunneling cases with emphasis on the spatial characteristics of the weak zone such as the strike and dip angle, and on the initial stress state. The results of the analyses were thoroughly examined so that the three-dimensional tunnel displacements at the tunnel crown and the sidewalls can be related to the spatial characteristic of the weak zone as well as the initial stress state. The results indicate that the effectiveness of the absolute displacement monitoring data as early warning indicators depends strongly on the spatial characteristics of the weak zone. It is also shown that proper interpretation of the absolute monitoring data can provide not only early warning for a weak zone outside the excavation area but also information on the orientation and the extent of the weak zone. Practical implications of the findings are discussed.

• Communications for Statistical Applications and Methods
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• v.30 no.2
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• pp.191-213
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• 2023

Unit distributions are frequently used in probability theory and statistics to depict meaningful variables having values between zero and one. Using convenient transformation, the unit inverse exponentiated weibull (UIEW) distribution, which is equally useful for modelling data on the unit interval, is proposed in this study. Quantile function, moments, incomplete moments, uncertainty measures, stochastic ordering, and stress-strength reliability are among the statistical properties provided for this distribution. To estimate the parameters associated to the recommended distribution, well-known estimation techniques including maximum likelihood, maximum product of spacings, least squares, weighted least squares, Cramer von Mises, Anderson-Darling, and Bayesian are utilised. Using simulated data, we compare how well the various estimators perform. According to the simulated outputs, the maximum product of spacing estimates has lower values of accuracy measures than alternative estimates in majority of situations. For two real datasets, the proposed model outperforms the beta, Kumaraswamy, unit Gompartz, unit Lomax and complementary unit weibull distributions based on various comparative indicators.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.1
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• pp.48-54
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• 2017

The purpose of this study was to provide fundamental data for the plans to reduce occupational stress by analyzing occupational stress of medical technologist. The experimental group comprised of 193 medical technologists working in Gyeonggi province. Occupational stress was 49.74 out of 100. In detail, job insecurity showed a high value of 64.42, followed by organizational system, lack of reward, physical environment, job demand, insufficient job control, interpersonal conflict, and occupational climate with respective values of 52.46, 52.30, 51.18, 49.57, 48.43, 39.78 and 39.77. It is recommended that those in high-stress job group increase physical activity and reduce job insecurity to improve health. The development of programs to reduce occupational stress are necessary, and this study can provide objective information using biological indicators.