• Journal of Industrial Convergence
• /
• v.21 no.7
• /
• pp.29-39
• /
• 2023

In the recent period, there have been numerous earthquakes both domestically and internationally, and buildings in South Korea are particularly vulnerable to seismic design and earthquake damage. Therefore, the objective of this study is to discover an effective method for assessing the seismic vulnerability of buildings and conducting a density analysis of high-risk structures. The aim is to model this approach and validate it using data from pilot area(Seoul). To achieve this, two modeling techniques were employed, of which the predictive accuracy of the statistical analysis technique was 87%. Among the machine learning techniques, Random Forest Model exhibited the highest predictive accuracy, and the accuracy of the model on the Test Set was determined to be 97.1%. As a result of the analysis, the district rating revealed that Gwangjin-gu and Songpa-gu were relatively at higher risk, and the density analysis of at-risk buildings predicted that Seocho-gu, Gwanak-gu, and Gangseo-gu were relatively at higher risk. Finally, the result of the statistical analysis technique was predicted as more dangerous than those of the machine learning technique. However, considering that about 18.9% of the buildings in Seoul are designed to withstand the Seismic intensity of 6.5 (MMI), which is the standard for seismic-resistant design in South Korea, the result of the machine learning technique was predicted to be more accurate. The current research is limited in that it only considers buildings without taking into account factors such as population density, police stations, and fire stations. Considering these limitations in future studies would lead to more comprehensive and valuable research.

• The Journal of Asian Finance, Economics and Business
• /
• v.6 no.3
• /
• pp.27-40
• /
• 2019

The study examines the effects of growth opportunities, debt maturity and liquidity risk on leverage, making use of a large panel of Chinese listed firms. Research on capital structure has broadened its scope from a single capital structure decision (the debt/equity choice) to various attributes of the debt in firms' capital structure. We use the system Generalized Method of Moments estimator to control for unobserved heterogeneity and the potential endogeneity of regressors. We find a negative relationship between growth opportunities and leverage. Further, we find that while the proportion of short-term debt attenuates the negative effect of growth opportunities on leverage, it negatively affects leverage as predicted by the liquidity risk hypothesis. When we distinguish between state owned firms and private controlled firms, we find evidence that these effects are only relevant to private controlled firms. However, our analysis indicates that the economic implication of liquidity risk effect is much lower for Chinese firms than that observed in the literature for US firms. Our study suggests that these differences can be explained by differences in the institutional environment in which firms operate. This finding related to Diamond's (1991) liquidity risk hypothesis extends our understanding of the relationship between liquidity risk and the debt maturity choice.

• Journal of the Korean Society of Safety
• /
• v.32 no.3
• /
• pp.112-116
• /
• 2017

This study applied risk indexes to the disaster flow event occurred at Mt. Umyeon region in 2011. A 2D hydrodynamic model was employed to calculate flow characteristics, and the model was validated against two dam break flow problems conducted by Bellos and EU CADAM project. The model performance was shown to be satisfactory. In order to determine which index is more appropriate to assess the vulnerability of debris flow, 3 risk indexes (FII, FHR and VDI) were considered. It was found that VDI, which determines the risk level only by the velocity factor, consistently predicted the risk level corresponding to 6 because the velocity range was widely organized. However, in the case of FII and FHR, the risk was reasonably quantified due to combined consideration of significant factors of flow velocity and debris thickness. Therefore, FII and FHR are expected to be more accurate than VDI. However, two indexes still need to be improved to include major factors such as debris density or material properties.

• Journal of Korean Public Health Nursing
• /
• v.29 no.2
• /
• pp.257-271
• /
• 2015

Purpose: This research examined the trend of school health education, using online research data on health behaviors of adolescents. Then it compared the health perceptions, healthy life practice, and health risk behaviors between students who received health education and students who did not. In addition, it predicted the impact of health education on health risk behaviors of students. Methods: Data from 72,435 participants of this survey were analyzed. Statistical analyses were performed on weighted data using the complex sampling design. Results: In the results of the research, general high schools students had the lowest rate of receiving health education, while sex education was the most actively held throughout the all locations. Next, medium-small cities had the lowest rate of receiving health education. Regarding health risk behaviors, students receiving health education had significantly lower rates of smoking, drinking, and sexual intercourse. Conclusion: This study shows that healthy life practices by students improves with the inclusion of health education, thus indicating that schools should invest in health education. This research generated evidence for the first time in Korea that school health education has a positive impact on health risk behaviors and provides basic data for policy development of school health education.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.3B
• /
• pp.248-253
• /
• 2011

Collision avoidance algorithm of vessels have been studied to avoid collision and grounding of a vessel due to human error. In this paper, We propose a collision avoidance algorithm using bayesian estimation theory for safety sailing and reduced risk of collision accident. We calculate collision risk for efficient collision avoidance using bayesian algorithm and determined the safest and most effective collision risk is predicted by using re-planned with re-evaluated collision risk in the future(t=t'). Others ship position is assumed to be informed from AIS. Experimental results show that we estimate the safest and most effective collision risk.

• Journal of Environmental Health Sciences
• /
• v.46 no.1
• /
• pp.1-10
• /
• 2020

Objectives: This study intends to evaluate the ecological risk of lead (Pb), arsenic (As), and their compounds according to the 2010 action plan on inventory and management for national priority chemicals and provide calculations of risks to the environment. By doing so, we aim to inform risk management measures for the target chemicals. Methods: We conducted species sensitivity distribution (SSD) analysis using the collected ecotoxicity data and obtained predicted no effect concentrations (PNECs) for the in-water environment using a hazardous concentration of 5% (HC5) protective of most species (95%) in the environment. Based on the calculated PNECs for aquatic organisms, PNEC values for soil and sediment were calculated using the partition coefficient. We also calculated predicted exposure concentration (PEC) from nation-wide environmental monitoring data and then the hazard quotient (HQ) was calculated using PNEC for environmental media. Results: Ecological toxicity data was categorized into five groups and five species for Pb and four groups and four species for As. Based on the HC5 values from SSD analysis, the PNEC value for aquatic organisms was calculated as 0.40 ㎍/L for Pb and 0.13 ㎍/L for As. PNEC values for soil and sediment calculated using a partition coefficient were 77.36 and 350.50 mg/kg for Pb and 24.20 and 112.75 mg/kg for As. The analysis of national environmental monitoring data showed that PEC values in water were 0.284 ㎍/L for Pb and 0.024 ㎍/L for As, while those in soil and sediment were respectively 45.9 and 44 mg/kg for Pb, and 11.40 and 19.80 mg/kg for As. Conclusions: HQs of Pb and As were 0.70 and 0.18 in water, while those in soil and sediment were 0.59 and 0.13 for Pb and 0.47 and 0.18 for As. With HQs <1 of lead and arsenic in the environment, their ecological risk levels are found to be low.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.22 no.3
• /
• pp.191-199
• /
• 2012

Objectives: The study aim was to evaluate the application of a chemical exposure assessment tool for the Korean workplace. The Ministry of Employment and Labor in Korea (KMOEL) introduced the need for workplace risk assessments in 2011, requiring the Korean chemical industry to consider both domestic and international chemical regulation policies (e.g., estimations of exposure scenarios). Exposure scenarios are required in the European Union as part of material safety data sheets (MSDS) under the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) system. Methods: Although many programs for the estimation of exposure have been developed worldwide, to date there is no standard for the Korean workplace. To develop programs suitable for the Korean workplace, we examined the applicability of the European Center for Ecotoxicology and Toxicology of Chemicals target risk assessment (ECETOC TRA), which is recommended by the European Chemical Agency (ECHA). Results: To investigate the applicability of the ECETOC TRA to Korean industry, this study simulated 15 industrial processes. The predicted respiratory exposures for four processes using origin input parameters were underestimated compared to the measured respiratory exposure. Using calibrated input parameters, results for two processes were underestimated compared to the measured respiratory exposure. This result suggests that the use of calibrated input parameters reduces the differences between predicted and measured respiratory exposure. Conclusions: we developed applicable exposure estimating method by modifying the ECETOC TRA program; one suggested the development of exposure estimating program that explains Korea domestic workplace exposure scenario.This study will support the introduction of exposure scenario in MSDS system and protect health of worker from hazardous chemical.

• Journal of Preventive Medicine and Public Health
• /
• v.38 no.2
• /
• pp.132-140
• /
• 2005

Objectives: To propose a risk-adjustment model from insurance claims data, and analyze the changes in cesarean section rates of healthcare organizations after adjusting for risk distribution. Methods: The study sample included delivery claims data from January to September, 2003. A risk-adjustment model was built using the 1st quarter data, and the 2nd and 3rd quarter data were used for a validation test. Patients' risk factors were adjusted using a logistic regression analysis. The c-statistic and Hosmer-Lemeshow test were used to evaluate the performance of the risk-adjustment model. Crude, predicted and risk-adjusted rates were calculated, and compared to analyze the effects of the adjustment. Results: Nine risk factors (malpresentation, eclampsia, malignancy, multiple pregnancies, problems in the placenta, previous Cesarean section, older mothers, bleeding and diabetes) were included in the final risk-adjustment model, and were found to have statistically significant effects on the mode of delivery. The c-statistic (0.78) and Hosmer-Lemeshow test ($x^2$=0.60, p=0.439) indicated a good model performance. After applying the 2nd and 3rd quarter data to the model, there were no differences in the c-statistic and Hosmer-Lemeshow $x^2$. Also, risk factor adjustment led to changes in the ranking of hospital Cesarean section rates, especially in tertiary and general hospitals. Conclusion: This study showed a model performance, using medical record abstracted data, was comparable to the results of previous studies. Insurance claims data can be used for identifying areas where risk factors should be adjusted. The changes in the ranking of hospital Cesarean section rates implied that crude rates can mislead people and therefore, the risk should be adjusted before the rates are released to the public. The proposed risk-adjustment model can be applied for the fair comparisons of the rates between hospitals.

• Journal of Korea Multimedia Society
• /
• v.23 no.7
• /
• pp.870-882
• /
• 2020

It is that failure of equipment at the factory site causes personal injury and property damage. We are required a real-time monitoring and risk forecasting techniques to prevent for equipment failure. In this paper, we proposed a 3-phase smart plug and real-time monitoring system that can be used in factories, and collected environmental information and power information using a smart plug to analyze the data. In order to analyze the correlation between the risk situation and the collected data, we predicted the risk situation using Linear Regression, SVM, and ANN algorithms. As a result, the SVM and ANN algorithms obtained high predictive accuracy and developed a mobile app that could use it to check the risk forecast results.

• Journal of Environmental Impact Assessment
• /
• v.1 no.1
• /
• pp.51-59
• /
• 1992

Environmental Impact Assessment(EIA) is defined as an activity designed to identify and predict the impact on the environment. In the process of an EIA, the quantitative evaluation is generally performed for the air and water quality which have the national environmental quality standards. But the predicted values for the air and water quality are simply compared to the environmental standards. At present, the EIA process of Korea has no consideration for the possible human health risk resulting from the development projects. Environmental Health Impact Assessment(EHIA) is an applied methodology of EIA to estimate the acceptable health risk caused by a specified level of environmental pollutants. Estimating the excessive lifetime risk that is a possibility of dying of a certain disease by environmental contaminants, is useful as an evaluation technique of EHIA. It is recommanded the decision-makers to make efficient use of EHIA not only the development projects but also legislative proposals, policies and programmes in future.