• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.42-54
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• 2018

This study is to establish the traffic volume-based warrants of left-turn lanes in unsignalized intersections based on a risk probability methodology. This study applied a risk probability of a potential rear-end collision between a left-turn vehicle and the immediately following through vehicle. With the shifted negative exponential model and the compound probability theorem, the risk probability can be expressed as the function of directional volumes, opposing volumes and the percentage of left-turns for a two-lane and four-land highway, respectively. The warrants of installing left-turn lanes on unsignalized intersections were developed with the risk probability. The warrants define the total approaching and opposing volumes to encourage a left-turn lane as a function of operating speed, percentage of left-turn, and number of lanes.

• Korean Journal of Community Nutrition
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• v.17 no.4
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• pp.365-375
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• 2012

The purpose of this study was to develop a risk communication material on artificial food color additives for elementary school students. The development was based on a previous study on the perception and information needs of elementary school students on artificial food colors including that the students usually were interested in artificial food colors, but didn't know about those well, and they wanted to get information on the safety of their intake, function and necessity of food color additives. Based on the above results, a comic book on artificial food colors was developed as a risk communication material for the elementary school students by brainstorming and consultation with experts. The book was titled as 'Variegated artificial food colors! Understanding and Eating'. It contained basic information on food additives focused on artificial food colors including definition, function, calculation of ADI, usage of artificial food colors, quizzes and useful web sites, etc. The results of field evaluation for the developed material by 101 elementary school students were very positive in getting the correct information, understanding artificial food colors and having proper attitude for healthy dietary life. Therefore, the developed material could be used to help elementary school students have proper perception on artificial food colors and facilitate the risk communication on food additives.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.10
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• pp.5260-5275
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• 2019

In the process of constructing the traditional offensive and defensive game theory model, these are some shortages for considering the dynamic change of security risk problem. By analysing the critical indicators of the incomplete information game theory model, incomplete information attack and defense game theory model and the mathematical engineering method for solving Bayes-Nash equilibrium, the risk-averse income function for information assets is summarized as the problem of maximising the return of the equilibrium point. To obtain the functional relationship between the optimal strategy combination of the offense and defense and the information asset security probability and risk probability. At the same time, the offensive and defensive examples are used to visually analyse and demonstrate the incomplete information game and the Harsanyi conversion method. First, the incomplete information game and the Harsanyi conversion problem is discussed through the attack and defense examples and using the game tree. Then the strategy expression of incomplete information static game and the engineering mathematics method of Bayes-Nash equilibrium are given. After that, it focuses on the offensive and defensive game problem of unsafe information network based on risk aversion. The problem of attack and defense is obtained by the issue of maximizing utility, and then the Bayes-Nash equilibrium of offense and defense game is carried out around the security risk of assets. Finally, the application model in network security penetration and defense is analyzed by designing a simulation example of attack and defense penetration. The analysis results show that the constructed income function model is feasible and practical.

• Archives of Craniofacial Surgery
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• v.17 no.2
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• pp.68-76
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• 2016

Background: In scalp allotransplantation, the scalp from a brain-dead donor, including hair, is transferred to a recipient with scalp defects. Opinions differ on the appropriateness of scalp allotransplantation. In order to maintain graft function and cosmetic outcomes, scalp transplantation recipients would need to receive lifelong immunosuppression treatments. The risks of this immunosuppression have to be balanced against the fact that receiving a scalp allotransplant does not extend lifespan or restore a physical function. Therefore, the present study aimed to investigate risk acceptance and expectations regarding scalp allotransplantation in different populations. Methods: A questionnaire survey study was conducted. A total of 300 subjects participated; survey was conducted amongst the general public (n=100), kidney transplantation recipients (n=50), a group of patient who required scalp reconstruction due to tumor or trauma (n=50), and physicians (n=100). The survey was modified by using the Korean version of the Louisville instrument for transplantation questionnaire. Results: Risk acceptance and expectations for scalp transplantation varied widely across the groups. Kidney transplantation recipients revealed the highest risk acceptance and expectations, whereas the physicians were most resistant to the risks of scalp transplantation. Conclusion: Our study demonstrates that, in specific groups, scalp allotransplantation and the need for immunosuppression carries an acceptable risk despite the lack of lifeextending benefits. Our results suggest that scalp allotransplantation can be an acceptable alternative to existing scalp reconstruction surgeries in patients with pre-existing need for immunosuppression.

• Journal of dental hygiene science
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• v.23 no.2
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• pp.142-153
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• 2023

Background: Cognitive impairment has been reported to be closely associated with poor oral health, and the relationship is bidirectional, as older adults with poor oral health and chewing function are at a higher risk of cognitive decline (CD). This cross-sectional study aimed to determine whether masticatory discomfort in Korean elderly increases the risk of daily living difficulty (DLD) related to CD and whether there is a difference in risk according to gender and age. Methods: The data used were obtained from the Korean Community Health Survey (2019). The final analysis included 22,154 people aged 65 years and older who completed the survey and responded to all items on the variables used in the study. Chi-square test, trend test, and complex sample logistic regression were performed for statistical analysis, to clarify the purpose of this study. Results: As masticatory discomfort increased, the elderly's DLD tended to increase (p-for trend, p<0.001). For logistic regression, adjusting for all covariates, participants who reported masticatory discomfort as "discomfort" (adjusted odds ratio [AOR]=2.45, 95% confidence interval [CI]=2.11~3.50) and "severe discomfort" (AOR=2.95, 95% CI=2.49~3.50) had a more than a two-fold increased risk of CD-related DLD compared to participants who reported "no discomfort at all." In age-stratified analyses, elderly men aged 75~84 years and elderly women aged 65~74 years had the highest risk of developing CD-related DLD. Conclusion: Oral care interventions to improve masticatory function in older adults may slow CD and improve CD-related DLD. We hope that this study will raise awareness among caregivers and clinical professionals regarding the importance of oral care for older adults with CD.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.608-613
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• 2007

Prediction of corporate bankruptcies has long been an important topic and has been studied extensively in the finance and management literature because it is an essential basis for the risk management of financial institutions. Recently, support vector machines (SVMs) are becoming popular as a tool for bankruptcy prediction because they use a risk function consisting of the empirical error and a regularized term which is derived from the structural risk minimization principle. In addition, they don't require huge training samples and have little possibility of overfitting. However. in order to Use SVM, a user should determine several factors such as the parameters ofa kernel function, appropriate feature subset, and proper instance subset by heuristics, which hinders accurate prediction results when using SVM In this study, we propose a novel hybrid SVM classifier with simultaneous optimization of feature subsets, instance subsets, and kernel parameters. This study introduces genetic algorithms (GAs) to optimize the feature selection, instance selection, and kernel parameters simultaneously. Our study applies the proposed model to the real-world case for bankruptcy prediction. Experimental results show that the prediction accuracy of conventional SVM may be improved significantly by using our model.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.495-500
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• 2003

Tight junctions (TJ) between adjacent Sertoli cells in testis are important for the formation of the blood testis barrier (BTB). In an effort to verify the reproductive health risk of endocrine-active chemicals (EACs), changes in the transepithelial electrical resistance (TER) and the expression of TJ genes were examined by co-planar polychlorinated biphenyl (PCB) treatment in cultured mouse Sertoli cells. Although the increase in TER of Sertoli cells was accelerated by 10 nM co-planar PCB, it was downregulated by 100 nM co-planar PCB. The expression of claudin-1 was downregulated by co-planar PCB in a concentration-dependent manner. On the contrary, the expression of claudin-1 was increased in the Sertoli cells by 10 nM co-planar PCB treatment. These results suggest that the structure and function of TJ may be targeted by co-planar PCB in Sertoli cells. Assessment of the structure and function of TJ in Sertoli cells might be useful for screening the reproductive health risk of EACs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.125-126
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• 2019

This study aims to recognize damage indicators of typhoon and to develop damage function's indicators, using information derived from the actual loss of typhoon Maemi. As typhoons engender significant financial damage all over the world, governments and insurance companies, local or global, develop hurricane risk assessment models and use it in quantifying, avoiding, mitigating, or transferring the risks. For the reason, it is crucial to understand the importance of the risk assessment model for typhoons, and the importance of reflecting local vulnerabilities for more advanced evaluation. Although much previous research on the economic losses associated with natural disasters has identified the risk indicators that are indispensable, more comprehensive research addressing the relationship between vulnerability and economic loss are still called for. Hence this study utilizes and analyzes the actual loss record of the typhoon Maemi provided by insurance companies to fill such gaps. In this study, natural disaster indicators and basic building information indicators are used in order to generate the vulnerability functions; and the results and indicators suggest a practical approach to create the vulnerability functions for insurance companies and administrative tasks, while reflecting the financial loss and local vulnerability of the actual buildings.

• Journal of Food Hygiene and Safety
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• v.19 no.1
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• pp.19-24
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• 2004

Dose-response models in microbial risk assessment can be divided into biologically plausible models and empirical models. Biologically plausible models are formed by the assumptions in dose distribution of microbes, host sensitivity to microbes, and minimal infectious dose of microbes : there are Exponential model and $\beta$-Poisson model, representatively. Empirical models are mainly used to express the toxicity of chemicals : there are Weibull-Gamma model etc. Deviance function (Y) is used to fit available data to dose-response models, and some dose-response models for food-borne pathogens are developed in humans and experimental animals.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.99-105
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• 2016

This study was conducted to develop a dummy in an environment similar to the human body, to prepare a standard for evaluation and to present the process of the production in order to evaluate the performance of the robot that can detect the persons needing rescue in a confined space, who are difficult for fire-fighting officials to rescue in case of fire and disaster. As a result, a standard for evaluation was developed and standardized into four parts 'Normal,' 'Risk Stage 1,' 'Risk Stage 2' and 'Risk Stage 3'based on the number of breath cycles, carbon dioxide concentration, core temperature and criteria for hearing to recognize the voice. In addition, in order to produce a dummy, fever, breathing capacity and voice output function were compared and analyzed. This study has significance that it built up basic data of the method of producing the actual dummy, by presenting characteristics and controlling methods using the waterproof insulation heating coil for the function, solenoid valve for the consecutive output of breathing capacity and USB program sound board for voice output.