• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.124-131
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• 2009

In any form of construction work, it is essential that accidents be prevented at every stage, from foundation preparation to build completion. For this, it is necessary to use models that can assess risk and provide instructions for safe work processes so that the risk of accidents is reduced. Currently, however, very few models can perform these tasks. In this paper, we present a model that assesses risk quantitatively by analyzing the risk factors involved in each stage of construction, such as foundation work, temporary work, structural work, equipment work, and finishing work. The model performs assessment based on examples of accidents and by investigating actual conditions during construction. In addition, we present in this paper a safety management system developed to assess risk during construction and to effectively train laborers.

• Fire Science and Engineering
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• v.25 no.6
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• pp.1-7
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• 2011

As population grows and urban facilities are concentrated in specific areas due to recent urbanization and industrialization, cities have structures vulnerable to both natural and man-made disasters. Most of these structures, whether buildings or residential houses, are left in a defenseless state if not given the appropriate check-up before they are built. The process of rapid urbanization without establishing the proper urban fire risk assessment will surely lead to disasters. This phenomenon occurred during the process of rapid urbanization and maybe said the result of chaotic urban expansion where modern urban infrastructure is not yet equipped in the city. Under the said circumstances, propagation processes of Korean urban fire cases were investigated to establish fire risk assessment system. Moreover, this paper explains the experiment performed for establishing urban risk assessment model. The said experiment was conducted using the new urban fire risk assessment model.

• Environmental Engineering Research
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• v.14 no.2
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• pp.120-125
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• 2009

Water stress has become a major concern in agriculture. Korea suffers from limited agricultural water supply, and wastewater reuse has been recommended as an alternative solution.A study was performed to examine the effects of microorganism concentration in the ponded-water of a paddy rice field with reclaimed-water irrigation for evaluating the microbial risk to farmers and neighborhoodchildren.Most epidemiological studies were performed based on an upland field, and they may not directly applicable to paddy fields. Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion. Their risk value increased significantly high level after irrigation and precipitation.It implies that agricultural activities such as plowing, and fertilizing, and precipitation need be practiced a few days after irrigation considering health risks. The results about field application of the microbial risk assessment using E. coli showed difference according to monitoring time and treatment plot. Result of the microbial risk assessment showed that risk values of ground-water and reclaimed secondary waste water irrigation were lower than directly use of wastewater treatment plants' effluent. This paper should be viewed as a first step in the application of quantitative microbial risk assessment of E. coli to wastewater reuse in a paddy rice farming.

• Journal of Radiation Protection and Research
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• v.35 no.1
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• pp.6-11
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• 2010

Embodying the safety of radioactive waste disposal requires the relevant safety criteria and the corresponding stylized methods to demonstrate its compliance with the criteria. This paper proposes a conceptual model of risk-based safety evaluation for integrating complex potential radiation exposure situations in radioactive waste disposal. For demonstrating compliance with a risk constraint, the approach deals with important exposure scenarios from the viewpoint of the receptor to estimate the resulting risk. For respective exposure situations, it considers the occurrence probabilities of the relevant exposure scenarios as their probability of giving rise to doses to estimate the total risk to a representative person by aggregating the respective risks. In this model, an exposure scenario is simply constructed with three components:radionuclide release, radionuclide migration and environment contamination, and interaction between the contaminated media and the receptor. A set of exposure scenarios and the representative person are established from reasonable combinations of the components, based on a balance of their occurrence probabilities and the consequences. In addition, the probability of an exposure scenario is estimated on the assumption that the initiating external factors influence release mechanisms and transport pathways, and its effect on the interaction between the environment and the receptor may be covered in terms of the representative person. This integrated approach enables a systematic risk assessment for complex exposure situations of radioactive waste disposal and facilitates the evaluation of compliance with risk constraints.

• Computational Structural Engineering : An International Journal
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• v.2 no.1
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• pp.19-23
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• 2002

A reliability-based cost-benefit model for the risk management of oil platforms in the formulation of optimal decisions based on life-cycle consideration is proposed. The model is based on structural risk assessments and the integration of social issues and economics into the management decision process. Structural risks result from the platform's exposure to the random environmental loading associated with the offshore site where it is located. Several alternative designs of a typical platform are proposed and assessed from the cost-effectiveness viewpoint. This assessment is performed through the generation of cost/benefit relationships that are used, later on, to select the optimal design.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.139-147
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• 2023

As heavy precipitation rates have increased due to climate change, the risk of landslides has also become greater. Studies in the field of disaster risk assessment predominantly focus on evaluating intrinsic importance represented by the use or role of facilities. This work, however, focused on evaluating risks according to the external conditions of facilities, which were presented via debris flow simulation. A random walk model (RWM) was partially improved and used for the debris flow simulation. The existing RWM algorithm contained the problem of the simulation results being overly concentrated on the maximum slope line. To improve the model, the center cell height was adjusted and the inertia application method was modified. Facility information was collected from a digital topographic map layer. The risk level of each object was evaluated by combining the simulation result and the digital topographic map layer. A risk assessment technique suitable for the polygon and polyline layers was applied, respectively. Finally, by combining the evaluated risk with the attribute table of the layer, a system was prepared that could create a list of objects expected to be damaged, derive various statistics, and express the risk of each facility on a map. In short, we used an easy-to-understand simulation algorithm and proposed a technique to express detailed risk information on a map. This work will aid in the user-friendly development of a debris flow risk assessment system.

• Environmental Analysis Health and Toxicology
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• v.25 no.2
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• pp.145-151
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• 2010

Perfluorinated chemicals (PFCs) is a kinds of persistent organic pollutants, and have the potential toxicity of which is causing great concern. In this study, we employed Oryzias latipes embryos to investigate the developmental toxicity of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)s compound using flowthrow system for 14 day. O. latipes embryos were exposed to solvent control, 20, 40 and 80 mg/L of PFOS and 62.5, 130, 260 mg/L of PFOA respectively. After exposure, hatchability, mortality, total length and heart beats were examined. Hatching rates were reduced approximately 27% in the 80 mg/L PFOS-treated group and 17% in the 62.5, 130 mg/L PFOA-treated groups. Heart beats in the PFOS-treated groups were reduced at 7 day but, PFOA-treated groups were increased heart beats. 80 mg/L PFOS treated group showed significant reduction in growth (total length) level to 90% of control. But PFOA did not showed significant effect on growth. In the 14 days $LC_{50}$ of PFOS and PFOA was 22.74 mg/L and 173 mg/L, respectively. The overall results indicated that the early stage of O. latipes might be a reliable model for the testing of developmental toxicity to perfluorinated chemicals.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.363-364
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• 2023

The tunnel construction projects is demanded more efficient risk management measures and loss forecasts to prepare for risk losses from an increase in the trend of tunnel construction. This study aims to analyze the risk factors that caused the loss of material in actual tunnel construction and to develop a quantified predictive loss model, based on the past loss record of tunnel construction projects.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.353-359
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• 2006

Transgenic Nicotiana benthamiana plants harboring the coat protein(CP) gene of Zucchini green mottle mosaic virus(ZGMMV) were chosen as a model host for the environmental risk assessment of genetically modified plants with virus resistance. This study was focused on whether new virus type may arise during serial inoculation of one point CP mutant of ZGMMV on the transgenic plants. In vitro transcripts derived from the non-functional CP mutant were inoculated onto the virus-tolerant and -susceptible transgenic N. benthamiana plants. Any notable viral symptoms that could arise on the inoculated transgenic host plants were not detected, even though the inoculation experiment was repeated a total of ten times. This result suggests that potential risk associated with the CP-expressiing transgenic plants may not be significant. However, cautions must be taken as it does not guarantee environmental safety of these CP-mediated virus-resistant plants, considering the limited number of the transgenic plants tested in this study. Further study at a larger scale is needed to evaluate the environmental risk that might be associated with the CP-mediated virus resistant plant.