• Journal of the Korean Institute of Gas
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• v.7 no.1 s.18
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• pp.33-40
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• 2003

In this work, a novel approach was introduced to assess cost of loss resulting from risk as well as to help deciding inspection period through quantifying risk. In order to quantifying risk of city gas pipeline, frequency and consequence analysis were required. The main causes of city gas accident were analyzed to be digging, external corrosion, ground movement, and equipment failure. Tools to evaluate frequency of each cause was also suggested. Among city gas accidents, fire damage is the dominant one and mainly discussed; fatality, burning injury, and damage to building were estimated using the consequence model suggested. By combining frequency and consequence analysis, evaluating cost of risk management together with calculating example. This work could be applicable for city gas companies to plan how to manage risk most effectively.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1027-1036
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• 2008

Value at Risk(VaR) is a fundamental tool for managing market risks. It measures the worst loss to be expected of a portfolio over a given time horizon under normal market conditions at a given confidence level. Calculation of VaR frequently involves estimating the volatility of return processes and quantiles of standardized returns. In this paper, we introduced and applied the CreditMetrics model to estimate the credit VaR of Korean Property and Casuality insurers.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.66-76
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• 1997

In order to investigate the generation of carbon monoxide and heat loss of incomplete combustion in compartment fires, an experiment was conducted in a small scale compartment by using methanol as a fuel. The concentration of carbon monoxide and the toxicity parameter showed high values when the mass air - to - fuel stoichiometric ratio is under 1.0. The constitution of the combustion gas was showed to estimate it from the . The heat loss due to incompleteness of combustion is about one third of heat of combustion in case of under 1.0.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.329-337
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• 2005

This study investigated prevalence of color vision loss different from children's residence. The study subjects are 3 to 6 grade's children of elementary school in four areas. The blood lead and urinary mercury were analysed using Atomic Absorption Spectroscopy. All of participations' blood lead and urine mercury concentration were below suggested level of concern such as criteria by CDC and ATSDR. Color vision was assessed by the Lanthony D-15 desaturated panel. Color vision loss was quantitatively established by the Color Confusion Index (CCI) and qualitatively classified by type of acquired dyschromatopsia according to Verriest's classification. The prevalence of color vision loss and CCI value for children in industrial area was significantly higher than other areas(p<0.05). However blood lead and urinary mercury concentration level was not correlated to the color vision loss. Therefore we believed that other environmental neurotoxic substance except metal had an effects on color vision loss for children in industrial area.

• Earthquakes and Structures
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• v.17 no.6
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• pp.557-566
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• 2019

The evaluation of the seismic hazard for a given site is to estimate the seismic ground motion at the surface. This is the result of the combination of the action of the seismic source, which generates seismic waves, the propagation of these waves between the source and the site, and site local conditions. The aim of this work is to evaluate the sensitivity of dynamic response of extended structures to spatial variable ground motions (SVGM). All factors of spatial variability of ground motion are considered, especially local site effect. In this paper, a method is presented to simulate spatially varying earthquake ground motions. The scheme for generating spatially varying ground motions is established for spatial locations on the ground surface with varying site conditions. In this proposed method, two steps are necessary. Firstly, the base rock motions are assumed to have the same intensity and are modelled with a filtered Tajimi-Kanai power spectral density function. An empirical coherency loss model is used to define spatial variable seismic ground motions at the base rock. In the second step, power spectral density function of ground motion on surface is derived by considering site amplification effect based on the one dimensional seismic wave propagation theory. Several dynamics analysis of a curved viaduct to various cases of spatially varying seismic ground motions are performed. For comparison, responses to uniform ground motion, to spatial ground motions without considering local site effect, to spatial ground motions with considering coherency loss, phase delay and local site effects are also calculated. The results showed that the generated seismic signals are strongly conditioned by the local site effect. In the same sense, the dynamic response of the viaduct is very sensitive of the variation of local geological conditions of the site. The effect of neglecting local site effect in dynamic analysis gives rise to a significant underestimation of the seismic demand of the structure.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.3
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• pp.259-267
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• 2016

The study performs a risk analysis on container ship accidents using accident data collected over the six years from 2006 to 2011, presents the resulting risk level, and suggests three risk mitigation measures to reduce the overall risk, for the safer operation of container ships. More specifically, starting from the initial accident of collision, we developed 13 different accident scenarios using event tree analysis based on which the overall risk level was obtained and presented as a FN curve. Since diverse human factors are the main cause of most of the ship accidents, our study focuses on the effect of reducing human causes on the resulting risk level. For the research we considered the injuries for the calculation of fatality with the help of MAIS. The results show that collision was the main type of accident, accounting for 62 % of all accidents, and the measures employed were proven to be effective in the sense that the risk level was much lowered and the average number of fatalities was also reduced. With more data accumulated, more precise risk level will be calculated with which the practical risk mitigating measures will be also developed. For future study, economic loss and environmental damage as consequences need to be considered.

• Asia pacific journal of information systems
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• v.18 no.4
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• pp.1-26
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• 2008

Rapid progress of information technology and widespread use of the personal computers have brought various conveniences in our life. But this also provoked a series of problems such as hacking, malicious programs, illegal exposure of personal information etc. Information security threats are becoming more and more serious due to enhanced connectivity of information systems. Nevertheless, users are not much aware of the severity of the problems. Using appropriate password is supposed to bring out security effects such as preventing misuses and banning illegal users. The purpose of this research is to empirically analyze a research model which includes a series of factors influencing the effectiveness of passwords. The research model incorporates the concept of risk based on information systems risk analysis framework as the core element affecting the selection of passwords by users. The perceived risk is a main factor that influences user's attitude on password security, security awareness, and intention of security behavior. To validate the research model this study relied on questionnaire survey targeted on evening class MBA students. The data was analyzed by AMOS 7.0 which is one of popular tools based on covariance-based structural equation modeling. According to the results of this study, while threat is not related to the risk, information assets and vulnerability are related to the user's awareness of risk. The relationships between the risk, users security awareness, password selection and security effectiveness are all significant. Password exposure may lead to intrusion by hackers, data exposure and destruction. The insignificant relationship between security threat and perceived risk can be explained by user's indetermination of risk exposed due to weak passwords. In other words, information systems users do not consider password exposure as a severe security threat as well as indirect loss caused by inappropriate password. Another plausible explanation is that severity of threat perceived by users may be influenced by individual difference of risk propensity. This study confirms that security vulnerability is positively related to security risk which in turn increases risk of information loss. As the security risk increases so does user's security awareness. Security policies also have positive impact on security awareness. Higher security awareness leads to selection of safer passwords. If users are aware of responsibility of security problems and how to respond to password exposure and to solve security problems of computers, users choose better passwords. All these antecedents influence the effectiveness of passwords. Several implications can be derived from this study. First, this study empirically investigated the effect of user's security awareness on security effectiveness from a point of view based on good password selection practice. Second, information security risk analysis framework is used as a core element of the research model in this study. Risk analysis framework has been used very widely in practice, but very few studies incorporated the framework in the research model and empirically investigated. Third, the research model proposed in this study also focuses on impact of security awareness of information systems users on effectiveness of password from cognitive aspect of information systems users.

• Journal of dental hygiene science
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• v.18 no.1
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• pp.1-8
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• 2018

Stroke is the second cause of death worldwide, although the survival period is increasing after the occurrence of stroke, severe physical disability is caused with aftereffect. Oral inflammation is not limited to the oral cavity, it can cause malignant changes in other tissues and organs. In previous studies, we confirmed the relationship between tooth loss and stroke due to periodontal inflammation. The purpose of this study was to investigate the relationship between oral health and stroke such as oral hygiene behavior, tooth loss and periodontal disease among Korean adults over 40 years of age. This study was analyzed using the 6th Korea National Health and Nutrition Examination Survey (KNHANES) data. A total of 3,389 adults over 40 years of age were analyzed as final subjects. Socioeconomic statuses and oral health status was analyzed using a complex sample analysis technique. Logistic regression was used to analyze the relationship of oral health and stroke, and 95% confidence intervals were computed using SPSS. When the prevalence of stroke according to oral hygiene behavior was checked, the prevalence of strokes was lower in subjects who had a lot of brushings per day and subjects who used oral hygiene products (p<0.05). The risk of stroke was 2.17 times (95% confidence interval, 1.43~3.28) higher in the group with less than 19 remaining teeth, but it was not statistically significant as a result of adjusting for age and sex, income level, education level, drinking and smoking (p>0.05). Loss of teeth was found to be associated with the risk factor of stroke. Therefore, loss of teeth due to periodontal disease is an additional issue that should be considered as a risk factor for stroke.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1419-1424
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• 2004

Railway safety is based on a risk analysis and safety assessment for the whole railway system as human, train, electric, signaling, operation, maintenance and etc. Therefore in this study, after investigating the accidents happened in electric railway on Choongang line for 5 years, from '97 to '01, a Data-Base was made through a cause and result analysis. In consideration of economic loss and human resources damage, a risk assessment for electric railway was also performed.

• Proceedings of the Korea Database Society Conference
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• 1999.10a
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• pp.129-139
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• 1999

현재의 조직 환경에서 정보 보호 수준의 결정은 필수 불가결한 이슈가 되고 있지만 정보 보호 수준 구축을 위한 기준은 상대적으로 부족한 실정이다. 이에 본 논문에서는 정보 보호 수준 결정에 있어서 기준이 될 수 있는 중요한 요소인 위험에 대해서 기존의 위험 평가 프로세스를 분석하여 개선된 위험평가 프로세스를 제시하고 허용 가능한 위험을 결정하기 위한 중요 기준인 목표 잉여 위험의 결정 방법에 대해 논하고자 한다.