• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.417-422
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• 2021

In this study, poly isocyanurate foam (PIR), poly urethane foam (PUR), and phenol foam (PF) of organic insulation materials were selected, and investigated using a cone calorimeter, as per ISO 5660-1. Standard materials (PMMA) were used to standardize the fire hazard assessment, and the fire risk was classified and evaluated by Chung's equations-III and IV. The fire performance index-II value of Chung's equations-II was the highest value with PF of 14.77 s²/kW. And the PUR was 0.08 s²/kW, the lowest value of fire performance index-II value. The fire growth index-II value was the lowest value with PF of 0.01 kW/s². And the PUR was 1.14 kW/s², the highest value of fire growth index-II value. The fire performance index-III (FPI-III) of Chung's equations-III had the lowest value for PUR (0.11) and the highest for PF (20.23). The PUR showed the highest value of the fire growth index-III (FGI-III) as 14.25, while the PF exhibited 0.13 regarded as the safest materials. The fire risk index-IV (FRI-IV) value of Chung's equation-IV was in the following order: PUR (130.03) >> PIR (19.13) > PMMA (1.00) > PF (0.01). Therefore, it was concluded that the fire risk associated with PF is the lowest, whereas that associated with PUR is the highest.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.93-98
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• 2016

This study analyzed the inflow characteristics of debris flow according to shape of defensive structure and computed risk index. In order to simulate debris flow, two shapes of defensive structure were considered. Initial mass distribution was set with a rectangular shape and defensive structures were set semi-circular shape and rectangular shape, respectively. It was found that a defensive structure with semicircular shape was more vulnerable to debris impact compared with rectangular shape because the flow mass became concentrated in quadrant part of the inner circle. If the velocity of the debris flow was less than 1 m/s, the risk assessment by FII (Flood Intensity Index) was much appropriate. However, when the movement of debris runout was faster than 1 m/s, the risk index of FHR (Flood Hazard Rating) provided improved classification due to its subdivided hazardous range.

• Journal of Korean Biological Nursing Science
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• v.21 no.2
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• pp.123-132
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• 2019

Purpose: The purpose of this study was to identify influencing factors of metabolic index and cardiovascular risk factors, on depressive and non-depressive groups, in vulnerable diabetic elderly women. Methods: Participants were 137 vulnerable diabetic elderly women, using health centers in D city. Data were collected through interviews September though December 2017. The metabolic index was measured using National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III), and cardiovascular risk factors were measured using Framingham Risk Score (FRS). Depressive and non-depressive groups were divided by the score of Geriartric Depress Scale Short Korea Version (GDSSF). Collected data were analyzed using a x2 test, independent t-test, and binary logistic regression, with the SPSS/WIN 25.0 program. Results: Vulnerable diabetic elderly women, did not exercise in the depressive groups, and had higher triglyceride (TG), total cholesterol (TC) and larger waists, than in the non-depressive group. Results show that lack of exercise (OR= 6.30), is the highest risk factor, influencing the depressive symptom in vulnerable diabetic elderly women. Conclusion: These results suggest that to reduce depressive symptom levels among vulnerable diabetic elderly women, nursing interventions are needed to increase exercise and decrease TG, TC, and waist size, particularly in improving exercise of vulnerable diabetic elderly women.

• The Journal of Society for e-Business Studies
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• v.20 no.2
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• pp.125-140
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• 2015

It is general that the impact of supply chain risk spread out to the whole network along the connected structure. Due to the risk propagation the probability to exposure a certain risk is affected by not only the characteristics of each risk factor but also network structure. It means that the structural connectivity among vertices should be considered while designing supply chain network in order to minimize disruption cost. In this research, the betweenness centrality has been utilized to quantitatively assess the structural vulnerability. The betweenness centrality is interpreted as the index which can express both the probability of risk occurrence and propagation of risk impact. With the structural vulnerability index, it is possible to compare the stability of each alternative supply chain structure and choose the better one.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.6
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• pp.512-519
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• 2011

Purpose: Although obesity is a well-established risk factor for many cancers, the effect of body mass index (BMI) on oral cancer risk remains controversial. We therefore investigated the effect of BMI on oral cancer risk in a case-control study in Korea. Methods: Overall, 364 patients with oral cancer and 439 community controls were enrolled. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression models, adjusted for age, smoking status and alcohol consumption. Results: We found no overall significant evidence of an association between oral cancer risk and BMI in either gender. However, when the relationship between BMI and oral cancer risk was examined according to female age groups (<50 and ${\geq}$50 years), there was a significant association between oral cancer risk and high BMI in female subjects younger than 50 years of age (OR=3.92, 95% CI 1.03~14.9, $P$ for trend=0.04), but not in older (${\geq}$50 years) female subjects (OR=1.11, 95% CI 0.55~2.24, $P$ for trend=0.76). There was no significant relationship between BMI and oral cancer risk in any of the male age subgroups. Conclusion: Our study provides the first epidemiological evidence supporting an association between obesity and an increased risk of oral cancer.

• Safety and Health at Work
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• v.9 no.2
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• pp.164-171
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• 2018

Background: In recent years, the interest in health and safety in the workplace has increased. Agriculture is one of the human work activities with the highest risk indexes. Studies on risk perception of agricultural workers are often referred to as specific risk factors (especially pesticides), but the risk perception plays an important role in preventing every kind of accident and occupational disease. Methods: The aim of this research is to test a new method for understanding the relation between risk perception among farmers and the main risk factors to which they are exposed. A secondary aim is to investigate the influence of training in risk perception in agriculture. The data collection was realized using a questionnaire designed to investigate the risk perception; the questionnaire was given to a sample of 119 agricultural workers in central Italy. Through the use of the "principal components analysis" it was possible to highlight and verify the latent dimensions underlying the collected data in comparison with scales of attitudes. Results: Results show that the highest percentage of strong negative attitude is among the people who have worked for more years, while farmers who have worked for fewer years have a marked positive attitude. Conclusion: The analysis of the questionnaires through the synthetic index method (Rizzi index) showed that agricultural workers involved, in particular the elderly workers, have a negative attitude towards safety; workers are hostile to safety measures if they have not attended special training courses.

• Journal of Korea Water Resources Association
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• v.47 no.9
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• pp.789-799
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• 2014

This study presented how to evaluate the inland inundation risk considering the characteristics of inland flood. Fuzzy AHP (Analytic Hierarchy Process), which can deal with the uncertainty or ambiguousness of the decision-making process, was used to estimate the inundation risk. The criteria used for inland inundation risk include the physical index, social index and inland flood. Each index contains three detailed indicators then total nine indicators were employed in this study. The inundation risk evaluation was carried out for each node (manhole) within the drainage system, not to the administrative extent, which enabled us to point out nodes with high risk. The proposed Fuzzy AHP was applied to Geoje district in Busan. The results indicated that the junction of Oncheoncheon and Geojecheon has high risk which is consistent with the fact that this junction has already experienced floods in the past. The proposed method can be used for evaluating inland inundation risk and preparing flood prevention plans in inland flood-prone urban areas.

• The Korean Journal of Financial Management
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• v.25 no.2
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• pp.69-101
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• 2008

We empirically investigate the option leverage property that should be priced under much more general conditions than the Black-Scholes assumptions and the option redundancy property that is based on the assumption that the underlying asset price follows a one-dimensional diffusion process and examine the systematic risk factors implied in the return dynamics of KOSPI 200 index options. We find that the option leverage pattern is similar to the theoretical result but the options are not redundant securities and in the nonlinear structure of option payoffs, the traders of KOSPI 200 index options price the systematic higher-moments and the negative volatility risk premium significantly affects delta-hedged gains, even after accounting for jump fears. But the empirical evidence on jump risk preference is less conclusive.

• Journal of the Korean Society of Safety
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• v.35 no.5
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• pp.22-29
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• 2020

In this study, combustion and smoke release characteristics of a non-class 1E cable for nuclear power plants were investigated according to aging period. The aging was reproduced through an accelerated aging method for interval of 10 years :10, 20, 30 and 40 year, which was applied the Arrhenius equation. The cable was subjected to accelerated aging. In order to understand combustion and smoke release characteristics, the cone calorimeter test was performed according to the standard code of KS F ISO 5660-1. Heat release rate, mass loss rate, average rate of heat emission and smoke production rate were examined through cone calorimeter test. Fire performance index, fire growth index and smoke factor were derived from test results for the comparison of quantitative fire risk. When comparing the fire performance index and the fire growth index, the early fire risk tends to decrease as aging progresses, which might be attributed from the fact that the volatile substances of cables were evaporated. However, when comparing the heat release rate, average rate of heat emission and mass loss rate, which represent the mid and late periods of the fire risk, the values of accelerated aging cables were much higher than those of non-aged cable, which signifies the unstable formation of the char layer resulted in the change in the performance of flame retardants. In addition, the results from the smoke characteristics show that the accelerated aging cables were lager than the non-aged cables in terms of overall fire risk. These results can be used as baseline data when assessing fire risk of cables and establishing fire safety code for nuclear power plants.

• Journal of the Korean Dietetic Association
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• v.22 no.2
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• pp.79-87
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• 2016

The aim of this study was to explore the relationship between demographic characteristics and atopic dermatitis, along with adolescents' body mass index. Also, this study explored the association between dietary intakes (fruits, soda, caffeinated beverages, instant food, cracker, vegetables, and milk) of adolescents and atopic dermatitis. Korea Youth Risk Behavior Web-based Survey for 2014 was used for data analysis, in which a total of 3,532,149 middle and high school students participated. Data were analyzed by descriptive analysis and logistic regression based on the complex sample design using SPSS ver.20.0 statistics. The results showed that males had a higher prevalence rate of atopic dermatitis than females. The significant association between body mass index and atopic dermatitis was found (F=46.625, P<0.001). Students who have higher levels of body mass index showed a higher prevalence rate of atopic dermatitis. Finally, the findings showed that the intake of vegetable and milk had associations with atopic dermatitis (F=6.795, P<0.001). Greater vegetable intake was associated with less atopic dermatitis whereas greater milk intake was associated with more atopic dermatitis prevalence. Based on the above results, we found that demographic characteristics, body mass index, and some dietary food intakes of adolescents had influences on prevalence rate of atopic dermatitis.