• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.1
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• pp.59-67
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• 2015

Because reservoirs that supply irrigation water play an important role in water resource management, it is necessary to evaluate the vulnerability of this particular water supply resource. The purpose of this study is to provide water supply risk maps of agricultural reservoirs in South Korea using irrigation vulnerability model and cluster analysis. To quantify water supply risk, irrigation vulnerability indices are estimated to evaluate the performance of the water supply on the agricultural reservoir system using a probability theory and reliability analysis. First, the irrigation vulnerability probabilities of 1,346 reservoirs managed by Korea Rural Community Corporation (KRC) were analyzed using meteorological data on 54 meteorological stations over the past 30 years (1981-2010). Second, using the K-mean method of non-hierarchical cluster analysis and pre-simulation approach, cluster analysis was applied to classify into three groups for characterizing irrigation vulnerability in reservoirs. The morphology index, watershed area, irrigated area, and ratio between watershed and irrigated area are selected as the clustering analysis parameters. It is suggested that the water supply risk map be utilized as a basis for the establishment of risk management measures, and could provide effective information for a reasonable decision making on drought risk mitigation.

• Nuclear Engineering and Technology
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• v.49 no.2
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• pp.306-312
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• 2017

The purpose of this research is to introduce the technical standard of accident sequence precursor (ASP) analysis, and to propose a case study using the dynamic-probabilistic safety assessment (D-PSA) approach. The D-PSA approach can aid in the determination of high-risk/low-frequency accident scenarios from all potential scenarios. It can also be used to investigate the dynamic interaction between the physical state and the actions of the operator in an accident situation for risk quantification. This approach lends significant potential for safety analysis. Furthermore, the D-PSA approach provides a more realistic risk assessment by minimizing assumptions used in the conventional PSA model so-called the static-PSA model, which are relatively static in comparison. We performed risk quantification of a steam generator tube rupture (SGTR) accident using the dynamic event tree (DET) methodology, which is the most widely used methodology in D-PSA. The risk quantification results of D-PSA and S-PSA are compared and evaluated. Suggestions and recommendations for using D-PSA are described in order to provide a technical perspective.

• Journal of Information Processing Systems
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• v.16 no.6
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• pp.1372-1390
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• 2020

An attractive user interface (UI) design with a clear user experience (UX) is the key for the success of applications. Therefore software development projects require very close collaboration between SI developers and front-end service developers. However, methodologies for software development only exist with inadequate development processes or work standards for collaboration. This survey derived 13 risk factors in developing UI/UX from 113 risk factors of IT projects through a questionnaire and factor analysis and proposed a collaboration-based UI/UX development model that can eliminate or mitigate six risks with high weights and reliability. To extract risk factors with high reliability, factor and reliability were analyzed to extract 13 major risks, and based on the expert opinions and the results of correlation analysis, UI/UX development stages were classified into planning, design, and implementation. The causal relationships between risks were verified through regression analysis. This study is the first to expertly analyze major risks based on collaboration in UI/UX development and derive a theoretical basis that can be used in project risk management. These findings are expected to provide a basis for research on development methodologies for higher levels of front-end services and to construct rational collaboration systems between SI practitioners and front-end service providers.

• Journal of Korea Water Resources Association
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• v.30 no.6
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• pp.679-690
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• 1997

The risk assessment model for hydrlolgic safety analysis of dam and levee in developed by using Monte-Carlo and AFOSM (Advanced First-Order Second-Moment) method. The fault tree analysis and four phases approach are presented for the safety eveluation of risk of dam and levee. The risk model consists of rainfall-runoff analysis, reservoir routing and channel routing considering the variations in the model parameter. For the rainfall-runoff analysis, KRRL method is adopted with 200-year precipitation and PMP (Probable Maximum Precipitation). Reservoir routing is performed by fourth order Runge-Kutta method and channel routing by standard step method. The suggested model will contribute to safety evaluation of dam and levee and their rehabilitation decision problem.

• Geomechanics and Engineering
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• v.18 no.5
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• pp.515-525
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• 2019

A karst collapse, as a natural hazard, is totally different to a normal collapse. In recent years, karst collapses have caused substantial economic losses and even threatened human safety. A risk assessment model for karst collapse was developed based on the fuzzy analytic hierarchy process (FAHP) and grey relational analysis (GRA), which is a simple and effective mathematical algorithm. An evaluation index played an important role in the process of completing the risk assessment model. In this study, the proposed model was applied to Jiaobai village in southwest China. First, the main controlling factors were summarized as an evaluation index of the model based on an investigation and statistical analysis of the natural formation law of karst collapse. Second, the FAHP was used to determine the relative weights and GRA was used to calculate the grey relational coefficient among the indices. Finally, the relational sequence of evaluation objects was established by calculating the grey weighted relational degree. According to the maximum relational rule, the greater the relational degree the better the relational degree with the hierarchy set. The results showed that the model accurately simulated the field condition. It is also demonstrated the contribution of various control factors to the process of karst collapse and the degree of collapse in the study area.

• Industrial Engineering and Management Systems
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• v.13 no.1
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• pp.87-100
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• 2014

Risk management is recognized as a significant element in Information Security Management while the failure mode and effects analysis (FMEA) is widely used in risk analysis in manufacturing industry. This paper aims to present the development work of the Information Security FMEA Circle (InfoSec FMEA Circle) which is used to support the risk management framework by modifying traditional FMEA methodologies. In order to demonstrate the "appropriateness" of the InfoSec FMEA Circle for the purposes of assessing information security, a case study at Hong Kong Science and Technology Parks Corporation (HKSTP) is employed. The "InfoSec FMEA Circle" is found to be an effective risk assessment methodology that has a significant contribution to providing a stepwise risk management implementation model for information security management.

• Convergence Security Journal
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• v.2 no.2
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• pp.67-75
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• 2002

The purpose of this study is to reflect the risk analysis results acquired while building an information system of an organization by applying a risk analysis model capable of analyzing the confronted risk, on the information system build methodology. Risk analysis, a method of utilizing the functional relation between risk, vulnerability and countermeasure of information assets, is used to evaluate the overall information risk level by analyzing the influence range of vulnerability imposed in the information asset of an organization, and the applications of the countermeasures on the frequency and intensity of the corresponding risk.

• Journal of the Korean Society of Safety
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• v.10 no.1
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• pp.56-63
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• 1995

Two methods of the numerical method of CPQRA(Chemical Process Quantitative Risk Analysis) and the manual method of IAEA(International Atomic Energy Agency) were used to estimate the individual risk and societal risk around the chemical plant. Where, the CPQRA is introduced to verify the theoritical background of the manual of international atomic energy agency. The Gaussian plume model which has a weather stability class D with velocity of 5m/s was applied to calculate dispersion of hazard material. Also, 8-point method was employed to the effects of accidents for wind distribution. Furthermore, historical record, FTA(Fault Tree Analysis) and ETA(Event Tree Analysis) were used to estimate the probability or frequency of accidents. Eventually, the individual risk shows isorisk contour and the societal risk shows F-N curve around hazard facility, especially in chemical plants. Caulculated results, which both individual and societal risk, by using IAEA manual show simillar results to those of calculation by numerical method of CPQRA.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7577-7581
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• 2013

The interleukin-18 promoter -607C>A gene polymorphism may be related to nasopharyngeal carcinoma (NPC) risk but the results of individual studies remain conflicting. A meta-analysis including 1,886 subjects from five individual studies was therefore performed to provide a more accurate estimation. Pooled odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs) were evaluated by fixed- or random-effects models. A significant relationship between interleukin-18 promoter -607C>A gene polymorphism and NPC was found in a dominant genetic model (OR: 1.351, 95% CI: 1.089-1.676, P=0.006, $P_{heterogeneity}$=0.904), a homozygote model (OR: 1.338, 95% CI: 1.023-1.751, P=0.034, $P_{heterogeneity}$=0.863), and a heterozygote model (OR: 1.357, 95% CI: 1.080-1.704, P=0.009, $P_{heterogeneity}$=0.824). No significant association was detected in either an allelic genetic model (OR: 1.077, 95% CI: 0.960-1.207, 0.207, $P_{heterogeneity}$=0.844) or a recessive genetic model (OR: 1.093, 95% CI: 0.878-1.361, P=0.425, $P_{heterogeneity}$=0.707). In conclusion, a significant association was found between interleukin-18 promoter -607C>A gene polymorphism and NPC risk. Individuals with the C allele of interleukin-18 promoter -607C>A gene polymorphism have a higher risk of NPC development.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.29-37
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• 1992

The risk of benzo(a)pyrene for cancer in the ambient air of Seoul was assessed by using the extrapolation methods. The average daily lifetime exposure of benzo(a)pyrene in the ambient air of Seoul was calculated at 6.97-24.30ng/$m^2$/day, which was based on the occurrence analysis of benzo(a)pyrene in the residential(Bull Kwang Dong) and traffic areas(Shin Chon) of Seoul. Using the dose scaling based on body surface area in comparisons of toxicity for extrapolation from animal to human and mathematical models from the high dose region, the low-dose risk was estimated. The response probabilities were estimated by the tolerance distribution models; Probit, Logit and Weibull model. They were consistent with the observed ones at experimental dose region. The unit risk estimates of these models were too low to be used. One-hit and multistage model to prove more conservative risk was selected. As a redult, the lifetime unit risk of benzo(a)pyrene for cancer and virtually safe dose were calculated; One-hit model provided the risk 2.8 $\times 10^{-7}$ and 3.4ng/$m^3$, respectively and multistage model provided 5.2 $\times 10^{-7}$ and 1.9ng/$m^3$ as the more conservatives. The lifetime excess risk estimates of benzo(a)pyrene for cancer were calculated at 0.37-1.30 persons/million persons by one-hit model and 0.69-2.41 persons/million persons by multistage model, which was considered in without virtual risk.