• Journal of the Korean Society of Safety
• /
• v.14 no.2
• /
• pp.62-69
• /
• 1999

The quantitative risk assessment and consequence analysis by accident scenario in the process of EPS(Expendable Poly Stylene) reaction process are conducted. And the decision making process is studied followed by selecting various alternatives to safety management and facility improvement. The result are as follows; 1) The object of decision making through comprehensive risk assessment are the scenario which can cause four major accident, which are made by process analysis, work analysis and hazard identification. 2) Frequency analysis of ETA, FTA, HRA and consequence analysis of accident to each have been conducted. The each frequency values are yielded $9.2{\times}10_{-5}/yr$ to scenarios $1, 8.2{\times}10^{-4}/yr$ to scenario 2, $4.5{\times}10^{-6}/yr$ scenario 3 and $1.8{\times}10^{-7}/yr$ to scenario 4. The each scenarios have been conducted consequence analysis. 3) The calculated values have been obtained 4.00 to scenario 1, 3.25 to scenario 2, 2.43 to scenario 3 and 1.34 to scenario 4, as the weight value had been applied to the quantitative and normalized criteria of all components. As a risk criteria, scenario 1 have been selected, which is the most dangerous scenario as a result of ranking the scenario. 4) According to the importance of FTA and contribute to scenario 1, the cost-benefit values are yielded $8.05\times10^5[￦/yr]$ to final alternative(Al), $1.55{\times}10^5[￦/yr]$ to final alternative(A2) and $2.32{\times}10^5[￦/yr]$ to final alternative(A3). As a result of final alternative(Al) has been selected, which is the most optimized alternative.

• Journal of the Korean Institute of Gas
• /
• v.18 no.6
• /
• pp.32-39
• /
• 2014

To ensure the reliability of the safety system so that handing large quantities of hazardous materials in chemical plant is considered basic information in chemical process design. However, the reliability of the production system may be reduced when the reliability of the safety system emphasized in order to ensure the safety of chemical process. It is necessary to balance the reliability of the production system and reliability of the safety. In this study, a quantitative risk assessment was performed by selecting the furnace process, which is widely used in the chemical plant in order to suggest a way to ensure the safety and productivity of chemical process, based on the quantitative data. Quantitative risk assessment methodology have been used directed graph analysis methodology. It is possible to evaluate the reliability of the safety system and the production system. In this study, the optimum system design requirement to improve the safety and the productivity of the furnace is two-out-of-three logic for TT and PT.

• Journal of the Korean Institute of Gas
• /
• v.22 no.4
• /
• pp.49-54
• /
• 2018

In the Active Pharmaceutical Ingredient(API) manufacturing company, since the product is produced by the chemical reaction, fire and explosion are frequently occurred in the process of inputting the raw powder as the chemical reaction stage. There are not many studies on safety measures through analysis of cause of accident in the actual chemical reaction stage. In this study, we investigated the heat flow in the boron removal reaction process to investigate the risk in the chemical reaction stage. The study reaction process was performed by using the reaction calorimeter for the products synthesized at the actual raw material in pharmaceutical factory. The risk was estimated by comparing the maximum temperature of the synthesis reaction, which can generate heat due to the failure of cooling in the actual manufacturing process, and the technical temperature. These results are applied to commercial manufacturing sites and safety measures to control the risk of runaway reaction due to reaction heat are suggested.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.4
• /
• pp.1080-1087
• /
• 2019

For a risk analysis in a chemical process, it is important to reflect correctly the characteristic properties of the target process. In this study, computational fluid dynamics (CFD) was adopted for the advanced risk analysis in a residual hydro desulfurization (RHDS) process by considering operation condition, layout of instruments and facilities, atmospheric condition, and wind direction. Release and explosion simulations for the RHDS by using FEA (Finite Element Analysis) and CFD showed the applicability of 3D scanning methods for estimation of release hole size and release amount.

• Journal of the Korean Data and Information Science Society
• /
• v.24 no.1
• /
• pp.1-12
• /
• 2013

In this paper, we introduce a continuous-time risk model where the surplus follows a diffusion process with positive drift while being subject to two types of claims. We assume that the sizes of both types of claims are exponentially distributed and that type I claims occur more frequently, however, their sizes are smaller than type II claims. We obtain the ruin probability that the level of the surplus becomes negative, by establishing an integro-differential equation for the ruin probability. We also obtain the ruin probabilities caused by each type of claim and the probability that the level of the surplus becomes negative naturally due to the diffusion process. Finally, we illustrate a numerical example to compare the impacts of two types of claim on the ruin probability of the surplus with that of the diffusion process in the risk model.

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

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.39 no.3
• /
• pp.129-138
• /
• 2016

The train-centric control systems development has some distinct points in that a big size of government budget is in general expended in there and the development duration seems to be long. In addition, the changes are ever made continuously in the capability and operational requirements for Trains. Thus, the impact of the potential changes in the required operational capability on the development activities can induce some type of project risks [7]. As such, proper management of project risk has been one of crucial subjects in the train systems development. All these notes combined together make it the significance of the safety management process be raised further up in the train-centric control systems development. As such, the underlying safety management process should be capable of appropriately handling the potential risks that can be created due to the unexpected changes and the long-term development period. The process should also be complemented for the safety consideration of train-centric control systems, for instance, stop. To study these aspect is the objective of the paper. To do so, a step-by-step approach to analyzing the safety management process is first presented. Then, to enhance the process some necessary and useful activities are added in terms of risk and safety management. Then, to pursue some enhancement on the process, a set of necessary and useful activities are added in terms of risk and safety management. The resultant process is further analyzed and tailored using a design structure matrix method. The resultant process is applied in a train-centric control development as a case study.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.4
• /
• pp.401-417
• /
• 2020

As an increasing demand for rapid railway transportation, the construction of sidetrack is inevitable to operate local and express trains simultaneously. However, the current technologies for the sidetrack construction method require a long construction period by interrupting the operation of the existing subway line, as well as cause a huge economic loss. Thus, it is necessary to study the sidetrack construction method under the special situation that the subway is in operation and to analyze the risk of the existing tunnel enlargement process for the sidetrack construction. Therefore, in this paper, the Government Complex Gwacheon station on Subway Line 4 was considered as a target station for the virtual sidetrack construction and the optimal sidetrack construction plan was derived. Subsequently, the application of risk management process was carried out in the order of identifying risk, risk response planning, performing a risk analysis, risk monitoring and control for potential risk events during the construction of sidetrack under the subway operation. A total of eight potential risk events and risk mitigation methods were selected, and a risk assessment matrix was established using the five-step risk probability and impact level criteria to perform the risk assessment including residual risks. Based on the results of the risk assessment, the risk grade and the reduction effect of each risk mitigation method were confirmed.

• Journal of the Korean Statistical Society
• /
• v.35 no.2
• /
• pp.193-199
• /
• 2006

We consider a zero coupon bond that is at the risk of multitype multiple defaults. Assuming defaults occur according to k Cox processes, we find a price process for zero coupon bonds. To derive this process we follow the Lando (1998)'s method which uses conditional expectations instead of the traditional methods.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.18 no.3
• /
• pp.34-41
• /
• 2010

'Aviation Safety' is the state in which the risk of harm to persons or of property damage is reduced to, and maintained at or below, an acceptable level through a continuing process of hazard identification and risk management in the aviation field. 'Risk' is the assessed potential for adverse consequences resulting from a hazard and 'Risk assessment' involves consideration of both the frequency and the severity of any adverse consequence. This study focused on the risk frequency about a case airport which does not meet the 'Runway end safety area' requirement of ICAO SARPs and Korea standards and used 'RSA risk model' for estimating the risk frequency. As results of this study, risk frequency of the runway end safety areas in the case airport is higher than that of 'Runway end safety area' requirement of ICAO SARPs and Korea standards, which means that alternatives for risk frequency mitigation to a level as low as reasonably practicable is required in the case airport. The optimum solution analysed from this study is to impose restriction of aircraft operation when the runway condition is poor(icing condition) and also it snows in the case airport.