• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.236-236
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• 2015

Flood is one of the major natural disasters affecting millions of people. Thailand also, frequently faces with this type of disaster. Especially, 2011 mega flood in Central Thailand, inundated highway severely attributed to the failure of national economic and risk to life. Lesson learned from such an extreme event caused flood monitoring and warning becomes one of the sound mitigations. The highway flood hazard mapping accomplished in this research is one of the strategies. This is due to highway flood is the potential risk to life and limb, and potential damage to property. Monitoring and warning therefore help reducing live and property losses. In this study, degree of highway flood hazard was assessed by weighting factors for each cause of the highway flood using Multi Criteria Analysis (MCA) based Analytic Hierarchy Process (AHP). These weighting factors are the essential information to classify the degree of highway flood hazard to enable pinpoint on flood monitoring and flood warning in hazard areas. The highway flood causes were then investigated. It was found that three major factors influence to the highway flood are namely the highway characteristics, the hydrological characteristics and the land topography characteristics. The weight of importance for each cause of the highway flood in the whole country was assessed by weighting 3 major factors influence to the highway flood. According to the result of MCA analysis, the highway, the hydrological and the land topography characteristics were respectively weighted as 35, 35 and 30 percent influence to the cause of highway flood. These weighting factors were further utilized to classify the degree of highway flood hazard. The Weight Linear Combination (WLC) method was used to compute the total score of all highways according to each factor. This score was later used to categorize highway flood as high, moderate and low degree of hazard levels. Highway flood hazard map accomplished in this research study is applicable to serve as the handy tool for highway flood warning. However, to complete the whole warning process, flood water level monitoring system for example the camera gauge should be installed in the hazard highway. This is expected to serve as a simple flood monitor as part of the warning system during such extreme or critical event.

• Journal of the Korea Convergence Society
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• v.13 no.2
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• pp.67-75
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• 2022

The purpose of this study is to present an appropriate management plan as a supplement to the scientific evidence of the currently operated distancing system for preventing COVID-19. The currently being used mathematical models are expressed as simultaneous ordinary differential equations, there is a problem in that it is difficult to use them for the management of entry and exit of small business owners. In order to supplement this point, in this paper, a method for quantitatively expressing the risk of infection by people who gather is presented in consideration of the allowable risk given to the gathering space, the basic infection reproduction index, and the risk reduction rate due to vaccination. A simple quantitative model was developed that manages the probability of infection in a probabilistic level according to a set of visitors by considering both the degree of infection risk according to the vaccination status (non-vaccinated, primary inoculation, and complete vaccination) and the epidemic status of the virus. In a given example using the model, the risk was reduced to 55% when 20% of non-vaccinated people were converted to full vaccination. It was suggested that management in terms of quarantine can obtain a greater effect than medical treatment. Based on this, a generalized model that can be applied to various situations in consideration of the type of vaccination and the degree of occurrence of confirmed cases was also presented. This model can be used to manage the total risk of people gathered at a certain space in a real time, by calculating individual risk according to the type of vaccine, the degree of inoculation, and the lapse of time after inoculation.

• Journal of Navigation and Port Research
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• v.33 no.4
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• pp.255-261
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• 2009

Prediction of the stability for ships is very complex in reality. In this paper, risk based approach is applied to predict the probability of capsize for a certified ship, which is effected by the forces of sea especially the wave loading Safety assessment and risk analysis process are also applied for the probabilistic prediction of stability for ships. The probability of shipsencountering different waves at sea is calculated by the existed statistics data and risk based models. Finally, ship capsizing probability is calculated according to single degree of freedom(SDF) rolling differential equation and basin erosion theory of nonlinear dynamics. Calculation results show that the survival probabilities of ship excited by the forces of the seas, especially in the beam seas status, can be predicted by the risk based method.

• Environmental Analysis Health and Toxicology
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• v.4 no.1_2
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• pp.55-65
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• 1989

Nevertheless the serious environmental pollution in Korea has been discussed in concern with health effect, the significant effect are not determined easily. Toxicological method has been used to establish safe levels of exposure for environmental pollutants to have threshold health effect below which significant effects are unlikely to occur. However the conventional method cannot to establish safe levels of exposure for non-threshold pollutants have been used to express comprehensive pollution degree, not in detailed toxic effects. Acceptable exposure or risk levels are decides by policymakers who consider descriptions and estimates of risks together with social and economic benefits. This paper focuses on the concept development of risk assessment and describes some risks of environmental pollution based on the surveyed date in Korea. The current concepts of risk assessment in policy descisions can be explored and areas for possible improvement, given current scientific knowledge are identified. The experience of foreign countries can provide a realistic basis for evaluating the existing data of environmental pollutants. To improve the environmental quality, risk regulation should be managed as soon as possible in Korea.

• Journal of Korean Dental Hygiene Science
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• v.5 no.2
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• pp.1-11
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• 2022

Background: This study was aimed at investigating the type of work of dental hygienists and identifying factors affecting the subjective health status according to hazardous risk factors in the working environment. Methods: From May 15 to 31, 2019, we surveyed 411 dental hygienists working at dental hospitals in the metropolitan area. SPSS 25.0 was used to perform the frequency analysis, t-test, one-way analysis of variance, Pearson's correlation analysis, and multiple regression analysis. Results: Regarding factors related to the degree of exposure to hazardous risk factors in the work environment and subjective health status, the more exposed the ergonomic (p<0.05) and psychological (p< 0.001)factors, the worse is the subjective health status. Conclusion: The results of this study suggest that the working environment should be improved for dental hygienists such that they can perform their duties in a safe environment.

• Korean Journal of Community Nutrition
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• v.24 no.3
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• pp.197-207
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• 2019

Objectives: This study examined the characteristics and nutritional risk of the elderly who receive home delivery services. We then analyzed the effects of the characteristics of the elderly who receive the home-delivery meal service on their nutritional risk. Methods: A total of 220 respondents who receive home-delivery meal service in Seoul participated in the survey. The survey consisted of the characteristics of the elderly (health status, tooth condition, physical activity, social participation activity, depression and relationship with neighbors), nutritional risk assessment and other general matters. The data was analyzed by using the SPSS program. Cross-tabulation analysis, t-test, correlation analysis and regression analysis were all conducted. Results: 47.0% of the subjects were under 80 years old and 53.0% were over 80 years old, The nutritional risk score, as evaluated by a Nutrition Screening Initiative (NSI) checklist was 10.7 points, and the high nutrition risk group was 91.5% of the subjects. The subjective self-health status score was 2.24 points (out of a total of 5 points) and the tooth status score was 3.30 points. The physical activity level was 2.17 points for the under 80 years old group and 1.76 points for the over 80 years old, and there was a significant difference according to age (p<0.01), The higher the health status, tooth condition, physical activity and social participation activity level, the lower was the nutritional risk. Further, the higher the degree of depression, the higher was the nutritional risk. Conclusions: For the healthy life of the elderly in the community, various welfare policies should be planned to increase social participation as well as to promote physical health and reduce depression.

• Journal of the Korean Society of School Health
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• v.22 no.2
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• pp.37-47
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• 2009

Purpose : To find degree of internet addiction of rural elementary school students and to assess the relationship of them to the health promoting behaviors in a rural area in chungnam province. Method : Children's grade, sex and their internet habits, and family background and internet addiction records, health promoting behavior scores of 5th and 6th grade of elementary school students. Self-recorded questionnaire surveys from 2nd December to December 20, 2008, and total 393 data were analysed. Results : The results of this study were summarized as follows: 1. The internet risk group of 5th and 6th grade of rural elementary school students were 18.3%. 2. Place of major using internet were home in 84.6% of male and using internet time were more than 2hours per day and major purpose of internet was game(72.9%) than female. 3. Significant negative correlation between the degree of internet addiction and the health promoting behavior(r=-0.245. p=0.000) 4. Health promoting behavior score was 138.24${\pm}$18.64 in internet non-addictive group and 126.66${\pm}$16.81 in potential risk group, 124.60${\pm}$19.85 in high risk group 5. As a result of multiple regression analysis, degree of internet addiction, school record, health status, concern to health of the students by the parents were related to the health promoting behavior and these provided predicted 21.7%.. Conclusion : The internet addiction risk group need for the health education including health promoting behavior and counseling for treatment of internet addiction.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.632-643
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• 2020

Purpose To investigate the correlation between magnetic resonance (MR) image-based radiomics features and the genomic features of breast cancer by focusing on biomolecular intrinsic subtypes and gene expression profiles based on risk scores. Materials and Methods We used the publicly available datasets from the Cancer Genome Atlas and the Cancer Imaging Archive to extract the radiomics features of 122 breast cancers on MR images. Furthermore, PAM50 intrinsic subtypes were classified and their risk scores were determined from gene expression profiles. The relationship between radiomics features and biomolecular characteristics was analyzed. A penalized generalized regression analysis was performed to build prediction models. Results The PAM50 subtype demonstrated a statistically significant association with the maximum 2D diameter (p = 0.0189), degree of correlation (p = 0.0386), and inverse difference moment normalized (p = 0.0337). Among risk score systems, GGI and GENE70 shared 8 correlated radiomic features (p = 0.0008-0.0492) that were statistically significant. Although the maximum 2D diameter was most significantly correlated to both score systems (p = 0.0139, and p = 0.0008), the overall degree of correlation of the prediction models was weak with the highest correlation coefficient of GENE70 being 0.2171. Conclusion Maximum 2D diameter, degree of correlation, and inverse difference moment normalized demonstrated significant relationships with the PAM50 intrinsic subtypes along with gene expression profile-based risk scores such as GENE70, despite weak correlations.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.87-98
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• 2011

In this study, we investigated and identified criterial human factors(errors), most of which lead to terrible ship accidents such as collisions, sinking, fire and explosions resulting both in human lives and physical damages to ships as well as surrounding environments. To this end, we went through the accident reports of 413 cases over 2005~2009 period and classified the human factors into 6 major factors with 19 sub ones which were constructed in hierarchical order. The relative importance of major factors was calculated and among others the lack of awareness turned out to be the most important factor with the weight of 0.391. The contributions of the results in the research are two fold: it will help (i) identify the root causes of ship accidents and prevent further potential ship related incidents, (ii) analyze the degree of the risk associated with the ship accidents, when risk analysis is performed.

• Steel and Composite Structures
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• v.45 no.2
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• pp.263-279
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• 2022

With the span and arch rib size of concrete-filled steel tube (CFST) arch bridges increase, the hydration heat of pumped mass concrete inside large-size steel tube causes a significant temperature variation, leading to a risk of thermal stress-induced cracking during construction. In order to tackle this phenomenon, a hydration heat conduction model based on hydration degree was established through a nonlinear temperature analysis incorporating an exothermic hydration process to obtain the temperature field of large-size CFST. Subsequently, based on the evolution of elastic modulus based on hydration degree and early-age creep rectification, the finite element model (FEM) model and analytical study were respectively adopted to investigate the variation of the thermal stress of CFST during hydration heat release, and reasonable agreement between the results of two methods is found. Finally, a comparative study of the thermal stress with and without considering early-age creep was conducted.