• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.4 no.1
• /
• pp.71-75
• /
• 1994

In this study, a thermoelastic stress index of (100) oriented single crystalline silicon wafer and a relationship between thermal stress and critical plastic deformation temperatures were simulated. The simulated results for the thermoelastic stress index indicated a maximum value on <110> direction and a minimum on <100>. Then, it could be predicted that silicon wafer is plastically deformable over 1000 K, based on the relationship between the thermal stress derived from the thermoelastic stress index and the critical plastic deformation temperature.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.7 no.3
• /
• pp.270-277
• /
• 1983

Plastic plane stress solutions are given for a center cracked strip, characterized by the Ramberg-Osgood plastic index, under bi-axial tension. Using a power law hardening stress-strain relation, an incremental plasticity finite element formulation is developed, and simple formulation is given for computing J-integral with nodal displacements. The near tip angular distribution of von Mises effective stress doesn't differ significantly in magnitude according to the change of loading stress and bi-axial load combination factor. But, for smaller plastic index, the location of its maximum value moves vertically at a head of crack. J-integral value, in the plastic zone near crack tip, decreases with load combination factor for large and small plastic index.

• Journal of Preventive Medicine and Public Health
• /
• v.29 no.3 s.54
• /
• pp.609-616
• /
• 1996

This study was conducted to evaluate the degree of stress state and the risk factors related to in 967 white collar workers and 275 blue collar workers by using Psycosocial Well-being Index. The results obtained were as follows : 1. In the white collar workers and blue collar workers, young age, low education and low income groups had high scores of stress, while in white collar workers, female had high scores of stress but in blue collar workers, male had high scores of stress. 2. According to psychosocial well-being index, mild stress sto were 73.9% and 53.1%, high risk stress state were 8.9% and 44.4%, and healthy state were 17.2% and 2.6% in white collar and blue collar workers respectively. 3. The total stress score was highly associated with the factors of depression, social performance and self-confidence, general well-being and vitality, and sleeping disturbance and anxiety in order. 4. In reliability test of stress factors, Cronbach's $\alpha$ coefficients of depression, social performance and self-confidence, general well-being and vitality, and sleeping disturbance and anxiety were 0.89, 0.81, 0.79, and 0.74 respectively. In conclusion, it suggested that age, sex, marital status, income, education, sleeping time, smoking and exercise habit were associated with stress score, all of the above factors should considered to occupational health.

• Journal of Korean Society for Atmospheric Environment
• /
• v.26 no.3
• /
• pp.253-264
• /
• 2010

This study investigates the relationship between daily mortality and heat stress in Seoul, using perceived temperatures (PT) derived from a heat budget model. During the summer season, observed PT intensity showed the biggest magnitude of summer heat stress from the middle 10 days of July to the first 10 days of August. The elderly (65 and above) were found to be the most vulnerable to heat stress. The threshold PT, with a significant increase in excess mortality, was $38^{\circ}C$. No time lagged effect was observed with summer heat stress, while a high correlation was observed between anomalies in PT and relative deviation of mortality. A comparison of the heat index and the discomfort index with excess mortality revealed that the discomfort index underestimated excess mortality, whereas the heat index could not appropriately explain the increase in excess mortality correlated with the increase in excess heat. In contrast, PT was found to be the weather element that best represents excess mortality due to heat stress, and is thus expected to serve as a more reliable forecast index of human biometeorology.

• Journal of Forest and Environmental Science
• /
• v.14 no.1
• /
• pp.89-100
• /
• 1998

The study was carried to investigate the change of internal stress and physical properties of paper by the mutiplying of paper structuring that is an useful means to maximize the performance and use of the fiber raw material. The effects of recycled fiber on the physical properties of multiplied paper also were studied. The beating increased the internal stress of single layered paper, while filler loading decreased the internal stress. Multiplying the structure of paper decreased the internal stress and the most of physical properties except for tear index. It was found that the properties of paper could be changed by the pulp type, beating and the combination of raw materials. The introduction of filler in the middle and/or outer layer could improved the internal stress, tensile index, tear index and burst index. The addition of recycled fiber increased the opacity and stiffness of paper in both single layered and multiplied paper. Multiplying the structure of paper improved the air permeability and stiffness, while decreased burst index.

• Journal of Korean Academy of Nursing
• /
• v.49 no.4
• /
• pp.437-448
• /
• 2019

Purpose: This study was conducted to test a path model for the factors related to undergraduate nursing students' clinical practicum stress, based on Lazarus and Folkman's stress-coping model. Methods: This study utilized a path analysis design. A total of 235 undergraduate nursing students participated in this study. The variables in the hypothetical path model consisted of clinical practicum, emotional intelligence, self-efficacy, Nun-chi, and nursing professionalism. We tested the fit of the hypothetical path model using SPSS/WIN 23.0 and AMOS 22.0. Results: The final model fit demonstrated a satisfactory statistical acceptance level: goodness-of-fit-index=.98, adjusted goodness-of-fit-index=.91, comparative fit index=.98, normed fit index=.95, Tucker-Lewis index=.92, and root mean square error of approximation=.06. Self-efficacy (${\beta}=-.22$, p=.003) and Nun-chi behavior (${\beta}=-.17$, p=.024) were reported as significant factors affecting clinical practicum stress, explaining 10.2% of the variance. Nursing professionalism (${\beta}=.20$, p=.006) and self-efficacy (${\beta}=.45$, p<.001) had direct effects on emotional intelligence, explaining 45.9% of the variance. Self-efficacy had indirect effects on Nun-chi understanding (${\beta}=.20$, p<.001) and Nun-chi behavior (${\beta}=.09$, p=.005) through emotional intelligence. Nursing professionalism had indirect effects on Nun-chi understanding (${\beta}=.09$, p=.005) and Nun-chi behavior (${\beta}=.09$, p=.005) through emotional intelligence. The variables for self-efficacy and nursing professionalism explained 29.1% of the Nun-chi understanding and 18.2% of the Nun-chi behavior, respectively. Conclusion: In undergraduate nursing education, it is important to identify and manage factors that affect clinical practicum stress. The findings of this study emphasize the importance of Nun-chi, self-efficacy, emotional intelligence, and nursing professionalism in the development of an educational strategy for undergraduate nursing students.

• The Korean Journal of Health Service Management
• /
• v.6 no.1
• /
• pp.163-172
• /
• 2012

The purpose of the study were to investigate the effect of laughter program on the stress of nursing college students in clinical practice. The research design is one group pretest-posttest survey. Thirty-eight nursing college students took part in the study. Laughter program was carried out for 1hour 6weeks. Laughter program showed significant change on the state anxiety, mood-emotion, laughter index, subjective stress and self esteem. The acquired data were analyzed with SPSS/win 15.0 using descriptive methods paired t-test, Pearson correlation coefficient. The research producted following results: Laughter program can be effective to decrease the clinical practice stress; anxiety, mood-emotion and subjective stress index. Laughter program can be effective to increase laughter index and self esteem of nursing college students. Based on the study, It is necessary to repeat studies and considering to develop proper methods of clinical practice stress of nursing college students. This study recommends that laughter program coupled with cognitive approaches could affect ways of nursing college students coping with stress and contribute to the improvement from increasing their satisfaction.

• KNOM Review
• /
• v.24 no.2
• /
• pp.35-47
• /
• 2021

Various stress exists in a modern society, which requires constant competition and improvement. A person under stress often shows his pressure in his facial expression and language. Therefore, it is possible to measure the pressure using facial expression and language analysis. The paper proposes a stress measurement system using facial expression and language sensitivity analysis. The method analyzes the person's facial expression and language sensibility to derive the stress index based on the main emotional value and derives the integrated stress index based on the consistency of facial expression and language. The quantification and generalization of stress measurement enables many researchers to evaluate the stress index objectively in general.

• Journal of Ecology and Environment
• /
• v.44 no.3
• /
• pp.115-125
• /
• 2020

Background: The phenomenon of tree dieback in forest ecosystems around the world, which is known to be associated with high temperatures that occur simultaneously with drought, has received much attention. Korea is experiencing a rapid rise in temperature relative to other regions. Particularly in the growth of evergreen conifers, temperature increases in winter and spring can have great influence. In recent years, there have been reports of group dieback of Pinus densiflora trees in Korea, and many studies are being conducted to identify the causes. However, research on techniques to diagnose and monitor drought stress in forest ecosystems on local and regional scales has been lacking. Results: In this study, we developed and evaluated an index to identify drought and high-temperature vulnerability in Pinus densiflora forests. We found the Drought Stress Index (DSI) that we developed to be effective in generally assessing the drought-reactive physiology of trees. During 2001-2016, in Korea, we refined the index and produced DSI data from a 1 × 1-km unit grid spanning the entire country. We found that the DSI data correlated with the event data of Pinus densiflora mass dieback compiled in this study. The average DSI value at times of occurrence of Pinus densiflora group dieback was 0.6, which was notably higher than during times of nonoccurrence. Conclusions: Our combination of the Standard Precipitation Index and growing degree days evolved and short- and long-term effects into a new index by which we found meaningful results using dieback event data. Topographical and biological factors and climate data should be considered to improve the DSI. This study serves as the first step in developing an even more robust index to monitor the vulnerability of forest ecosystems in Korea.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.10
• /
• pp.3058-3067
• /
• 1996

With increasing use of ceramics/metal bonded joints, It is required to analyze the residual stress distribution and stress singularity at an interface edge for its bonded joints. In this paper, the residual stress distribution and stress singularity index of the ceramics/metal bonded joints were analyzed by using 2-dimensional elastic boundary element method. The variations of residual stress distribution and stress singularity index are studied with changes for the combinations of ceramics/metal bodned joints.