• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.32-41
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• 2011

By using a newly developed Korean risk-based corrective action (K-RBCA) software (K-RBCA) and the RBCA Tool Kit, risk assessment was performed on a site that was contaminated with aromatic hydrocarbons and heavy metals. Eight chemicals including benzene, ethylbenzene, xylenes, naphthalene, benz(a) anthracene, benzo(b) fluoranthene, benzo(a) pyrene, and arsenic that exceeded the US EPA Soil Screening Level were chosen as the target pollutants. A conceptual site model was constructed based on the site-specific effective exposure pathways. According to the RBCA Tool Kit the carcinogenic risk of arsenic was larger than $10^{-6}$, which is the generally acceptable carcinogenic risk level. The K-RBCA estimated the same level of carcinogenic risk for arsenic. With the RBCA Tool Kit, the carcinogenic risk of benzo(a) pyrene was estimated to be about $1.3{\times}10^{-6}$. However, with the K-RBCA benzo(a) pyrene did not exhibit any risk. The inconsistency between the softwares was attributed to the different fundamental settings (i.e., medium division) between the two softwares. While the K-RBCA divides medium into surface soil, subsurface soil, and groundwater, the RBCA Tool Kit divides medium into only soil and groundwater. These differences lead to the different exposure pathways used by the two softwares. The K-RBCA considers the exposure pathways in surface soil and subsurface soil separately to estimate risk, however, the RBCA Tool Kit considers the surface soil and subsurface soil as one and uses the integrated exposure pathways to estimate risk. Thus the resulting risk is higher when the RBCA Tool Kit is used than when the K-RBCA is used. The results from this study show that there is no significant difference in the risks estimated by the two softwares, thus, it is reasonable to use the K-RBCA we developed in risk assessment of soil and groundwater. In addition, the present study demonstrates that the assessor should be familiar with the characteristics of a contaminated site and the assumptions used by a risk assessment software when carrying out risk assessment.

• The Korean Journal of Applied Statistics
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• v.27 no.5
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• pp.681-691
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• 2014

Ranking-based conjoint analysis(RBCA) and choice-based conjoint analysis(CBCA) have attracted significant interest in various fields such as marketing research. When conducting research, the researcher has to select one suitable approach in consideration of strengths and weaknesses. This article performs an empirical comparison of the predictability of RBCA and CBCA in order to provide criterion for the selection. A new concept of measurement set is developed by combining the ranking set and choice set. The measurement set enables us to apply two approaches separately on the same consumer group that allows a fair comparison of predictability. RBCA and CBCA are conducted on consumer preferences for RTD-coffee; subsequently, the predicted values of market shares and hit rates are compared. The study result reveals that their predictabilities are not significantly different. Further, the result indicates that RBCA is recommended if the researcher wants to improve data quality by filtering out poor responses or to implement the market segmentation. In contrast, CBCA is recommended if the researcher wants to lessen the burden on the respondents or to measure preferences under similar conditions with the actual marketplace.

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.1-11
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• 2011

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.871-873
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• 2002

RBAC은 역할 계층구조에서 권한의 계승과 의무분리와 같은 제약조건을 다룸으로써 접근권한의 관리를 수월하게 하고 기업환경을 잘 반영말 수 있는 장점이 있다. 하지만 RBAC은 현실세계의 기업환경에서 빈번히 이루어지는 권한의 위임을 제대로 구현하지 못한다는 문제점을 가지고 있다. 본 논문에서는 자신의 고유역할 뿐만 아니라 상위 역할로부터 위임받은 새로운 위임 역할을 생성함으로써 역할계층 구조상의 다른 역할의 사용자에게 다른 과업을 할당해 줄 수 있도록 하여, 최소 권한의 원칙을 만족하는 다단계 위임을 구현하였다. 위임 시에 생길 수 있는 보안 문제를 해결하기 위해서 역할단위가 아닌 과업단위의 위임으로 제안하고, 과업단위의 의무분리를 적용하였으며, 위임 할 수 있는 과업을 규정하고 최하위 역할을 지정하였다. 기존의 다단계 모델에서 제안된 기법과의 비교를 통해서 본 논문에서 제안된 기법이 실제 기업에서 이루어지는 다단계 위임을 타당하게 구현할 수 있음을 보인다. 또한 T-RBCA을 기반으로 ARBAC97을 적용해서 제안된 기법을 모델링하고 Prototype을 구현하였다.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.630-635
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• 2013

There is a need to establish systematic procedure of groundwater quality standards, however, there were no specified basis for establishing substances and values in Korean groundwater quality standards for non-drinking water. In this study, we reviewed basis for deriving groundwater quality standard in the developed countries, considering carcinogenic and non-carciongenic risk via inhalation and dermal contact exposure pathways. Also, we reviewed the prior systematic procedure of standards related to water quality (e.g. drinking water, surface water, and wastewater). USEPA RAGS, ASTM RBCA, and Massachusettes presented the formulas for deriving groundwater concentrations of chemicals and there were similarity and differences. We suggests systematic procedure of groundwater quality standards, as follows. (1) Selection of groundwater pollutants population, (2) Possibility of risk assessment, (3) Selection of monitoring priority substances, (4) Monitoring, (5) Risk assessment, (6) Selection of groundwater quality standard candidates, (7) Selection of new substances and values for groundwater quality standards. Especially, groundwater concentration of hazardous material were presented according to revised risk formulas via inhalation and dermal contact.