• Tunnel and Underground Space
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• v.23 no.6
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• pp.457-469
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• 2013

We have analyzed the regional in-situ stress pattern using 460 stress measurement data at about 100 test sites in Korea, and suggested correlation equations of stress-depth and stress ratio-depth. We made Korea Stress Map(KSM) as in-situ stress fields of the Korean peninsula, combining with a paleo-stress analysis according to the geological period and a stress estimation from focal mechanism. We confirmed the reliability and applicability of correlation equations derived in this study, comparing with worldwide stress-depth patterns, and also estimated the pattern of in-situ stress fields of north-eastern Asia including Korea, China and Japan, comparing with World Stress Map.

• Geomechanics and Engineering
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• v.22 no.6
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• pp.475-488
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• 2020

The recent increase in the use of Expanded Polystyrene (EPS) geofoam in construction and geotechnical projects has driven researchers to investigate its behavior, more deeply. In this paper, a series of experimental tests to investigate the stress-strain behavior and the mechanical properties of EPS blocks, under monotonic axial loading are presented. Four different densities of cylindrically shaped EPS with different dimensions are used to investigate the effects of loading rate, height and diameter, as well as the influence of the density of EPS on the stress-strain response. The results show that increasing the height of the EPS samples leads to instability of the sample and consequent lower resistance to the applied pressure. Large EPS samples show higher Young's modulus and compressive resistance due to some boundary effects. An increase in the rate of loading can increase the elastic moduli and compressive resistance of the EPS geofoam samples, which also varies depending on the density of the samples. It was also determined that the elastic modulus of EPS increases with increasing EPS density. By implementing an efficient numerical procedure, the stress-strain response of EPS geofoam samples can be reproduced with great accuracy. The numerical analysis based on the proposed method can used to evaluate the effect of different factors on the behavior of EPS geofoam.

• Journal of Korean Academy of Nursing
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• v.37 no.6
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• pp.986-993
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• 2007

Purpose: The purpose of this study was to compare stress levels of elementary students according to three regional levels: a large city, a medium-sized city, and a rural area. Methods: This was a descriptive comparative survey using a convenience sample of 1,161 5th-and 6th-grade students. The stress level was measured by a stress scale that consisted of 65 items regarding personal characteristics, family, school, and peer factors. The data were analyzed by ${\chi}^2-test$, t-test, ANOVA and multiple regression using the SPSS 10.0 statistical program. Results: Overall, the mean stress scores reported by the participants were near the middle of a 5-point scale and the level of family-related stress was highest, followed by peer, school, and individual-related stress. Sixth-graders and female students showed higher stress levels than 5th-graders and male students, respectively. The participants reporting unsatisfaction with their lives and those living in large cities tended to have significantly higher stress levels. Conclusion: Grade, gender, life satisfaction, and regional levels were all significant factors associated with high stress levels among elementary students. Development of stress management programs for this specific population, especially targeting students who are female and living in large cities, is needed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.16-22
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• 2003

The focal mechanisms of the earthquakes occurred in 2001 and 2002 are analyzed to understand the regional stress and tectonics in and around Korean Peninsula. The forty -three fault plane solutions are derived using the polarities of first arrival P-waves recorded at KIGAM, Bmh and KEPRI stations. The result suggest that thrust motion with significant amount of strike slip component is dominant mode of faulting. The larger population of mechanism is characterized by WNW-ESE striking nodal planes. NE-SW direction is interpreted as dominant compressional axis orientation of stress field. These solutions are similar to those of medium size earthquakes studied previously, which is known as typical regional tectonic stress orientation in and around Korean Peninsula.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.353-361
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• 2023

Background: Noise has been linked to an increased risk of various health issues, including stress, anxiety, insomnia, and cardiovascular disorders. However, research on the relationship between residential traffic noise and mental health in South Korea is limited. Objectives: This study aims to examine the correlation between regional traffic noise levels and mental health using an ecological study design. Methods: In this ecological study, all data were collected from the Korean Statistical Information Service. Traffic noise data in residential areas and the prevalence of mental health indices in 44 cities with noise monitoring stations were obtained. Pearson correlation coefficients were calculated to assess the relationship between regional traffic noise levels and mental health indices. Results: Daytime traffic noise levels were found to have a positive correlation with stress perception (r=0.428, p=0.004) and showed a borderline positive correlation with depressive symptom prevalence (r=0.273, p=0.073). In cities with airports, significant correlations was observed between 24-hour average noise levels and depressive symptoms (r=0.604, p=0.010), whereas this relationship was not observed in cities without airports (r=0.048, p=0.813). Multiple regression analysis, which adjusted for factors such as age, gender ratio, smoking, obesity, unemployment, urban size, and the presence of an airport, confirmed the relationship between 24-hour average noise levels and stress perception (beta=0.287, p=0.024). Conclusions: This study identified correlations between regional traffic noise levels and depressive symptoms or stress perception in adults, with a more pronounced effect in areas with airports. These findings suggest a potential impact of residential traffic noise on mental health, highlighting the importance of preventive measures like noise management in urban planning to promote mental well-being.

• Journal of Ecology and Environment
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• v.38 no.1
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• pp.1-14
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• 2015

Whilst it is clear that increasing temperatures from global environmental change will impact the positions of alpine treelines, it is likely that a range of regional and local scaled factors will mediate the overall impact of global scale climate drivers. We summarized 12 categories of abiotic and biotic factors as 4 groups determining treeline positions. First, there are global factors related to climate-induced growth limitation and carbon limitation. Second, there are seven regional and local factors related to treeline dynamics including frost stress, topography, water stress, snow, wind, fire and non-fire disturbance. Third, species-specific factors can control treeline dynamics through their influence on reproduction and life history traits. Fourth, there are positive feedbacks in structuring the dynamics of treelines. Globally, the commonly accepted growth limitation hypothesis is that growth at a treeline is limited by temperature. Meanwhile, positive feedbacks between canopy cover and tree establishment are likely to control the spatial pattern and temporal dynamics of many treelines. The presence of non-linear dynamics at treelines has implications for the use of treelines as barometers of climate change because the lagged responses and abrupt shifts inherent in non-equilibrium systems may combine to mask the overall climate trend.

• Research in Community and Public Health Nursing
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• v.31 no.spc
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• pp.577-590
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• 2020

Purpose: The purpose of this study was to find out the suicidal ideation rate of the elderly including individual and regional factors by sex. Methods: This is secondary analysis study that combines the data of the 2017 Community Health Survey with the e-indicator data set of the National Statistical Office, and a descriptive correlation study. Statistical analysis used hierarchical logistic regression by SAS 9.4. Results: The 11.5% of the elderly had suicidal ideation within the last year, and 18.4% in Chungnam is the highest. Individual characteristics include females, older people, lower education levels, no job or housewife, no spouse, less than seven hours of sleep per day on the average, low subjective health, high subjective stress, and the worse their economic conditions, the more they had suicide ideation. Considering regional characteristics, suicidal ideation tended to increase significantly as the number of hospital beds per 1,000 people and the rate of obesity was lower, the rate of stress perception was higher, and the odds value was small. When both individual and regional factors were considered, the model conformity of the suicidal ideation improved (ICC=0.0814). Conclusion: In order to lower the suicidal rate of the elderly, it seems that both individual and community factors need to be comprehensively approached from the stage of suicidal ideation in the community.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.51-57
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• 2011

Purpose: The aim of this study is to identify clinical usefulness of Wide Beam Reconstruction (WBR) which is called Xpress.cardiac$^{TM}$ to confirm the agreement between segmental perfusion and regional wall motion in myocardium compared to conventional OSEM method. Materials and Methods: Subjects were separated two groups. First group was composed of 20 normal control group. Second group was composed of 10 patients (abnormal group) who had coronary artery disease. Subjects underwent myocardial perfusion SPECT ($^{201}Tl$ rest and $^{99m}Tc$-MIBI stress). Image acquisition and reconstruction were that rest stage was each step per 30, 15 seconds and stress stage was each step per 25, 13 seconds, OSEM and WBR methods were applied. Segmental perfusion and regional wall motion were applied 20-segment model of QPS, QGS algorithm in AutoQuant. Status of perfusion was composed of 5 point scoring system (0=normal, 1=mild, 2=moderate, 3=severe hypokinesia, 4=dyskinesia). Status of regional wall motion was also composed of 5 point scoring (0=normal, 1=mild, 2=moderate, 3=severe hypokinesia, 4=dyskinesia). We evaluated the agreement between conventional OSEM and WBR through automatic quantification value. Results: The agreement of rest segmental perfusion between conventional OSEM and WBR in normal patients was 99% (396/400, k=0.662, p<0.0001) and one of rest regional wall motion was 83.8% (335/400, k=0.283), the agreement of stress segmental perfusion was 95.8%(383/400, k=0.656), one of stress regional wall motion was 87.3% (349/400, k=0.390). The match rate of rest segmental perfusion in abnormal patients was 83% (166/200, k=0.605, p<0.0001) and one of rest regional wall motion was 55.5% (111/200, k=0.385), the agreement of stress segmental perfusion was 79.5% (159/200, k=0.682), one of stress regional wall motion was 63.5% (127/200, k=0.486). Conclusion: Compared to conventional OSEM, WBR method had a good agreement of segmental perfusion in myocardium in normal and abnormal groups. However regional wall motion showed meaningful low agreement. Although WBR offers high resolution and contrast ratio, it is not useful method for gated myocardial perfusion SPECT.

• Journal of the Korean Geographical Society
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• v.39 no.1
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• pp.13-26
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• 2004

This paper examined the possibility of NET application for a relative weather stress index in Korea. The characteristic of NET distribution used temperature, relative humidity, wind speed which forecasting at Korean Meteorological Administration were analyzed. Regional critical values of daily maximum NET of stress index for summer resembled the distribution of daily maximum temperature because were not impacted wind and humidity but temperature. Regional critical values of daily minimum NET of stress index for winter distributed variously compared with summer. The highland region and the northern region of Seoul were impacted of low temperature and coastal region which strong wind. The occurrences of stressful days did not vary in summer, but obviously increased in winter after mid-1990s.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.116-121
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• 2004

It is known that the transportation stress of market pigs can affect their carcass quality and that blood concentrations of glucose, creatine kinase (CK) and lactate dehydrogenase (LDH) are indicators of the transportation stress. Fifty-seven gilts and 57 barrows weighing approximately 110 kg were randomly assigned into six groups in a 3 [high (0.31 $m^2/100$ kg BW)-, medium (0.35 $m^2$)- and low (0.39 $m^2$)-stocking densities]${\times}2$[1 h vs. 3 h transportation time] arrangement of treatments. Blood samples were taken during transportation and after 2 h lairage. The percentage of "standing" animals during transportation was less in the low- than in the mediumor high-stocking density; the opposite was true for the "sitting" posture. Plasma concentrations of glucose, CK and LDH increased after loading and declined to the resting levels after lairage. Concentrations of CK and LDH were greater in the 3 h vs. 1 h transportation group. Moreover, the LDH concentration was less in the low- than in the medium- or high-density group. Also detected was a significant interaction between the stocking density and transportation time in all of these blood variables. The incidence of pale, soft and exudative (PSE) carcass was greatest in the high-stocking density group. Interestingly, the PSE incidence increased following the 3 h vs. 1 h transportation at the low-density, but not at the medium-density. Results suggest that the medium-density may be preferable to the lowdensity in the long-distance transportation.