• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.1
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• pp.31-39
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• 2017

The goal of this study was to efficiently analyze the relationships of the number of thefts with related factors, considering the spatial patterns of theft crimes. Theft crime data for a 5-year period (2009-2013) were collected from Haeundae Police Station. A logarithmic transformation was performed to ensure an effective statistical analysis and the number of theft crimes was used as the dependent variable. Related factors were selected through a literature review and divided into social, environmental, and defensive factors. Seven factors, were selected as independent variables: the numbers of foreigners, aged persons, single households, companies, entertainment venues, community security centers, and CCTV (Closed-Circuit Television) systems. OLS (Ordinary Least Squares) and GWR (Geographically Weighted Regression) were used to analyze the relationship between the dependent variable and independent variables. In the GWR results, each independent variable had regression coefficients that differed by location over the study area. The GWR model calculated local values for, and could explain the relationships between, variables more efficiently than the OLS model. Additionally, the adjusted R square value of the GWR model was 10% higher than that of the OLS model, and the GWR model produced a AICc (Corrected Akaike Information Criterion) value that was lower by 230, as well as lower Moran's I values. From these results, it was concluded that the GWR model was more robust in explaining the relationship between the number of thefts and the factors related to theft crime.

• Journal of Environmental Health Sciences
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• v.45 no.1
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• pp.9-17
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• 2019

Objectives: This study examined the safety of tattoo ink by analyzing the phenol contents in tattoo inks and its risk assessment of selected phenol. Methods: A sample of 30 tattoo inks was purchased, the phenol contents were analyzed, and a risk assessment on dermal exposure from tattooing was carried out. Hazard identification was collected from toxicity data on systemic effects caused by dermal exposure to phenol, and the most sensitive toxicity value was adopted. Exposure assessment ($Exposure_{phenol}$) was calculated by applying phenol contents and standard exposure factors, while dose-response assessment was based on the collected toxicity data and skin absorption rate of phenol, assessment factors (AFs) for derived no-effect level ($DNEL_{demal}$). In addition, the risk characterization was calculated by comparing the risk characterization ratio (RCR) with $Exposure_{phenol}$ and $DNEL_{dermal}$ Results: The phenol concentration in the 30 products was from 1.4 to $649.1{\mu}g/g$. The toxicity value for systemic effects of phenol was adopted at 107 mg/kg. $Exposure_{phenol}$ in tattooing was from 0.000087 to 0.040442 mg/kg. $DNEL_{dermal}$ was calculated at 0.0072 mg/kg (=toxicity value 107 mg/kg ${\div}$ AFs 650 ${\times}$ skin absorption rate 4.4%). Thirteen out of 30 products showed an RCR between 1.02 and 5.62. The RCR of all red inks was above 1. Conclusions: Phenol was detected in all of the 30 tattoo inks, and the RCR of 13 products above 1 indicates a high level of risk concern, making it necessary to prepare safety management standards for phenol in tattoo inks.

• Journal of the Korean Geotechnical Society
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• v.31 no.6
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• pp.59-69
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• 2015

Recently, landslide and debris-flow disasters caused by severe rain storms have frequently occurred. Many researches related to landslide susceptibility analysis and debris-flow hazard analysis have been conducted, but there are not many researches related to mobilization analysis for landslides transforming into debris-flow in slope areas. In this study, statistical analyses such as discriminant analysis and logistic regression analysis were conducted to develop a mobilization criterion using geomorphological and geological factors. Ten parameters of geomorphological and geological factors were used as independent variables, and 466 cases (228 non-mobilization cases and 238 mobilization cases) were investigated for the statistical analyses. First of all, Fisher's discriminant function was used for the mobilization criterion. It showed 91.6 percent in the accuracy of actual mobilization cases, but homogeneity condition of variance and covariance between non-mobilization and mobilization groups was not satisfied, and independent variables did not follow normal distribution, either. Second, binomial logistic analysis was conducted for the mobilization criterion. The result showed 92.3 percent in the accuracy of actual mobilization cases, and all assumptions for the logistic analysis were satisfied. Therefore, it can be concluded that the mobilization criterion for debris-flow using binomial logistic regression analysis can be effectively applied for the prediction of debris-flow hazard analysis.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.1-10
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• 2009

Recently the large scale of forest disaster such as landslide and forest fire gives a very bad impact on not only forest ecosystem but also farm business so that it has became the main issue of environmental problems. In this study, the landslide hazard area forecast method was developed by considering not only the topographic thematic maps based on GIS and satellite images but also amount of rainfall data, which are very important factors of landslide. Uljin-gun was selected as the study area and the GIS weight score and overlay analysis were applied to topographical map and meteorological observation map. Finally the landslide area distribution map was constructed by considering the evaluation criteria. Also, the accuracy could be acquired by comparing the landslide hazard area forecast map and real damaged area extracted from satellite image.

• Fire Science and Engineering
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• v.17 no.3
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• pp.61-73
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• 2003

Most of the accidents occurred from the chemical plants are related to the catastrophic gas release events when the large amount of toxic materials is leaked from its storage tank or transmitting pipe lines. In this case, the greatest concerns are how the spreading behaviors of leakages are depended on the ambient conditions such as air stability and other environmental factors. Hence, we have focused on the risk assessments and consequential analysis for chlorine as an illustrative example. As appeared in the result, Fire & Explosion Index depicted it a bit dangerous with presenting the comprehensive degrees of hazard 90.7. And as a result of Phast6.0/ALOHA, the trends of each scenario appeared considerably identical although there are some differences in the resulting effects according to the input data for the Gas Model. The consequence analysis is performed numerically based on the dense gas mode. In the future, using more correct input data, material properties, and topographical configuration, the method of this research will be useful for the guideline of the risk assessment when the release of toxicants breaks out.

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.82-94
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• 2010

This study was undertaken in an attempt to provide scientific grounds in explaining the causes of environmental and respiratory diseases resulting from air pollutants in Gyeongju and its neighboring areas. In relation to heavy metals, lead (Pb) was $0.0135{\sim}0.1744\;{\mu}g/m^3$ and high in order of Pohang, Ulsan, and Gyeongju while nickel (Ni) was $0.0023{\sim}0.0115\;{\mu}g/m^3$. The concentrations of heavy metals in the investigated areas did not exceed the environmental standards or Guideline Value of Korea or other countries. However, it is considered necessary to apply intensive control to some heavy metals including cadmium (Cd) that show a relatively high level of hazard. Based on the responses to the survey, measured personal interest in environmental pollution and the basic knowledge of the causes of the respiratory diseases was higher in those with a family history of allergic reactions to metals and bronchial asthma. The incidence of allergic disease was higher in those who are currently in poor health state. In addition, the general knowledge of environmental pollutants was higher in those with higher educational level and those with a higher interest in environmental pollution. Personal interest in environmental pollution was higher in those with higher basic knowledge of environmental pollutants. Therefore, it is necessary to increase the awareness through better education and campaigns on environmental pollution.

• Journal of Preventive Medicine and Public Health
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• v.53 no.5
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• pp.342-352
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• 2020

Objectives: The aim of this retrospective cohort study was to investigate whether non-alcoholic fatty liver disease (NAFLD) was associated with incident bone mineral density (BMD) decrease. Methods: This study included 4536 subjects with normal BMD at baseline. NAFLD was defined as the presence of fatty liver on abdominal ultrasonography without significant alcohol consumption or other causes. Decreased BMD was defined as a diagnosis of osteopenia, osteoporosis, or BMD below the expected range for the patient's age based on dual-energy X-ray absorptiometry. Cox proportional hazards models were used to estimate the hazard ratio of incident BMD decrease in subjects with or without NAFLD. Subgroup analyses were conducted according to the relevant factors. Results: Across 13 354 person-years of total follow-up, decreased BMD was observed in 606 subjects, corresponding to an incidence of 45.4 cases per 1000 person-years (median follow-up duration, 2.1 years). In the model adjusted for age and sex, the hazard ratio was 0.65 (95% confidence interval, 0.51 to 0.82), and statistical significance disappeared after adjustment for body mass index (BMI) and cardiometabolic factors. In the subgroup analyses, NAFLD was associated with a lower risk of incident BMD decrease in females even after adjustment for confounders. The direction of the effect of NAFLD on the risk of BMD decrease changed depending on BMI category and body fat percentage, although the impact was statistically insignificant. Conclusions: NAFLD had a significant protective effect on BMD in females. However, the effects may vary depending on BMI category or body fat percentage.

• Korean Journal of Health Education and Promotion
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• v.22 no.1
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• pp.17-40
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• 2005

This study was aimed to analyze the status of the a health education and the health behavior, and to identify the effected factors of health promotion behavior based on Green's PRECEDE Model among high school students The data was collected by interview survey with self-administration questionnaire from the selected high school students during the end of the second semester, 2001, and 1,591 students are analyzed. The statistical method of the analysing for effected factors of health promotion behavior was used the Multiple Linear Regression Analysis by SPSS package program. The results of this study are as fellows. 1. The index of the health educational contents shows the 18.14 points per 86 points, 18.96 points in girl students, 17.53 points in boy students. 2. In the index of health promotion behaviors was 84.9 points per 140 full points in all average; 61 points per 100 points. The experienced rate of smoking was $35\%$ of all students, $38.5\%$ of boy students, $30.6\%$ of girl students each. The experienced rate of drinking was $62.2\%$ of all students, $61.6\%$ of boy students, $69.4\%$ of girl students. 3. The effected factors of the health promotions behaviors to analyse by multiple linear regression model was sports activity, the degree of satisfaction of their school life, the academic records of school, the present health conditions, their awareness for hazard of smoking for their health, the experiences of the smoking, their stresses(R$^2$ =0.174). and the factors as the experiences of drinking, their stresses, and the indexes for the health education contents in their school were added in girls students.

• Journal of Environmental Impact Assessment
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• v.15 no.6
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• pp.373-383
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• 2006

The spatial mapping of risk is very useful data in planning for disaster preparedness. This research presents a methodology for making the landslide life risk map in the Boeun area which had considerable landslide damage following heavy rain in August, 1998. We have developed a three-stage procedure in spatial data analysis not only to estimate the probability of the occurrence of the natural hazardous events but also to evaluate the uncertainty of the estimators of that probability. The three-stage procedure consists of: (i)construction of a hazard prediction map of "future" hazardous events; (ii) validation of prediction results and estimation of the probability of occurrence for each predicted hazard level; and (iii) generation of risk maps with the introduction of human life factors representing assumed or established vulnerability levels by combining the prediction map in the first stage and the estimated probabilities in the second stage with human life data. The significance of the landslide susceptibility map was evaluated by computing a prediction rate curve. It is used that the Bayesian prediction model and the case study results (the landslide susceptibility map and prediction rate curve) can be prepared for prevention of future landslide life risk map. Data from the Bayesian model-based landslide susceptibility map and prediction ratio curves were used together with human rife data to draft future landslide life risk maps. Results reveal that individual pixels had low risks, but the total risk death toll was estimated at 3.14 people. In particular, the dangerous areas involving an estimated 1/100 people were shown to have the highest risk among all research-target areas. Three people were killed in this area when landslides occurred in 1998. Thus, this risk map can deliver factual damage situation prediction to policy decision-makers, and subsequently can be used as useful data in preventing disasters. In particular, drafting of maps on landslide risk in various steps will enable one to forecast the occurrence of disasters.

• Structural Engineering and Mechanics
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• v.73 no.3
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• pp.339-351
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• 2020

Earthquakes are natural disasters that cause serious social disruptions and economic losses. In particular, they have a significant impact on critical lifeline infrastructure such as urban water transmission networks. Therefore, it is important to predict network performance and provide an alternative that minimizes the damage by considering the factors affecting lifeline structures. This paper proposes a probabilistic reliability approach for post-hazard flow analysis of a water transmission network according to earthquake magnitude, pipeline deterioration, and interdependency between pumping plants and 154 kV substations. The model is composed of the following three phases: (1) generation of input ground motion considering spatial correlation, (2) updating the revised nodal demands, and (3) calculation of available nodal demands. Accordingly, a computer code was developed to perform the hydraulic analysis and numerical modelling of water facilities. For numerical simulation, an actual water transmission network was considered and the epicenter was determined from historical earthquake data. To evaluate the network performance, flow-based performance indicators such as system serviceability, nodal serviceability, and mean normal status rate were introduced. The results from the proposed approach quantitatively show that the water network is significantly affected by not only the magnitude of the earthquake but the interdependency and pipeline deterioration.