• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.59-63
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• 2014

Smoke is one of the most critical factor when escaping from the fire since it reduces visibility and interrupts finding emergency exit lights. Therefore, it is recommended that an evacuation simulation program should incorporate the smoke factor. In addition, it is suggested that the program should include not only the unilateral damage by the smoke but also the detour evacuation by risk communication. In this study, MAS (Multi Agent System)-based simulation program which incorporates the reduced walking speed by smoke and adopts the dispersion evacuation logic during escaping from the fire. To make comparison, a commercial evacuation program, Pathfinder was used. It was found that the simulation results of MAS (Multi Agent System)-based program is better than Pathfinder in terms of safe evacuation. It means that evacuation simulation need a additional evaluation categories that include not only quick evacuation time but also safe evacuee number.

• Journal of Korea Game Society
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• v.15 no.3
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• pp.41-50
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• 2015

This study attempted to identify differences in user experience such as spatial presence, social presence, flow, empathy, anxiety, and perceived risk between simulating characters of animation and of actual userimage. The playtesting method was conducted on 60 male smokers using 'Smoking Sims', a simulation game produced by The Center for Health Communication Studies. The results found that the simulation of actual image character is higher in the level of perceived risks for smoking, spatial presence, social presence, flow, and empathy than the simulation of animation character. The study shows that identification with a game character affects user experience and enhances the effectiveness of perceived risks as well. It emphasizes the importance of game design to implement identification in serious game like a smoking cessation simulation.

• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.78-90
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• 2009

Recently, operation of highway is the complex digital Infrastructure based on complicated IT. The application of IT is increasing more and more in digital Infrastructure. Though IT is very convenient, if unpredicted operating risk of highway occurs, widespread damage can be large. When operating risk of highway occurs, road users are out of smoothly-run service because of the operating interruption. This risk causes unpredicted operating management cost and additional maintenance cost. It will excess over the planned operating cost, which may leads to users's unsafety and operator's insolvency because of income loss. Until now, related studies to find out the risk are not sufficient. The purpose of this study is to suggest risk cost items and to estimate the reasonable risk cost by using simulation method in case of occurring the huge power failure at the operating digitalized highway. This study indicates the several plans to hedge against risk cost and the management of highway project. From now on, it will be used as basic data to confirm the soundness of operating system in Digital Infrastructure.

• Food Science of Animal Resources
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• v.35 no.5
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• pp.674-682
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• 2015

The objective of this study was to evaluate the risk of illness from Campylobacter spp. on ham. To identify the hazards of Campylobacter spp. on ham, the general characteristics and microbial criteria for Campylobacter spp., and campylobacteriosis outbreaks were investigated. In the exposure assessment, the prevalence of Campylobacter spp. on ham was evaluated, and the probabilistic distributions for the temperature of ham surfaces in retail markets and home refrigerators were prepared. In addition, the raw data from the Korea National Health and Nutrition Examination Survey (KNHNES) 2012 were used to estimate the consumption amount and frequency of ham. In the hazard characterization, the Beta-Poisson model for Campylobacter spp. infection was used. For risk characterization, a simulation model was developed using the collected data, and the risk of Campylobacter spp. on ham was estimated with @RISK. The Campylobacter spp. cell counts on ham samples were below the detection limit (<0.70 Log CFU/g). The daily consumption of ham was 23.93 g per person, and the consumption frequency was 11.57%. The simulated mean value of the initial contamination level of Campylobacter spp. on ham was −3.95 Log CFU/g, and the mean value of ham for probable risk per person per day was 2.20×10⁻¹². It is considered that the risk of foodborne illness for Campylobacter spp. was low. Furthermore, these results indicate that the microbial risk assessment of Campylobacter spp. in this study should be useful in providing scientific evidence to set up the criteria of Campylobacter spp..

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.421-436
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• 2016

Public-Private-Partnerships tend to be committed high project development cost and recover the cost through future revenue during the operation period. In general, long-term concession can bring on more revenue to private investors, but short-term concession less revenue due to the short recovering opportunities. The concession period is usually determined by government in advance or by the private sectors's proposal although it is a very crucial factor for the PPPs. Accurate traffic forecasting should be most important in planing and evaluating the operation period in that the forecasted traffic determines the project revenue with user fees in PPPs. In this regards, governments and the private investors are required to consider the traffic forecast risk when determining concession period. This study proposed a model for the optimal concession period in the PPPs transportation projects. Monte Carlo simulation was performed to find out the optimal concession period while traffic forecast uncertainty is considered as a project risk under the expected return of the private sector. The simulation results showed that the optimal concession periods are 17 years and 21 years at 5.5% and 7% discount level, respectively. This study result can be applied for the private investors and/or any other concerned decision makers for PPPs projects to set up a more resonable concession period.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.100-102
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• 2015

In recent years, using a smart phone that can access the Internet becomes routine in society through development of information and communication technology. On land, as especially actual accidents and research results show risk that using the smart phone while driving at the same time, and there are traffic laws and regulations that restriction of using of smart phone. But the regulations on the use of smart phones at sea is incomplete state. On this paper. We invested present status of use and reality of smart phone at sea and analyzed the subjective risk for judging to apply to regulation. And we analyzed risk quantitatively by using the simulation experiment; it Suggested a direction of guideline for use of smart phone at sea.

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

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.373-378
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• 2006

Recently the technical advances and complexities have generated much of the difficulties in managing the project resources, for both scheduling and costing to accomplish the project in the most efficient manner. The project manager is frequently required to render judgments concerning the schedule and resource adjustments. This research develops an analytical model for a schedule-cost and risk analysis based on visual PERT/CPM. We used a three-step approach: 1) in the first step, a deterministic PERT/CPM model for the critical path and estimating the project time schedule and related resource planning and we developed a heuristic model for crash and stretch out analysis based upon a time-cost trade-off associated with the crash and stretch out of the project. 2) In second step, we developed web-based risk evaluation model for project analysis. Major technologies used for this step are AHP (analytic hierarchy process, fuzzy-AHP, multi-attribute analysis, stochastic network simulation, and web based decision support system. Also we have developed computer programs and have shown the results of sample runs for an R&D project risk analysis. 3) We developed an optimization model for project resource allocation. We used AHP weighted values and optimization methods. Computer implementation for this model is provided based on GUI-Type objective-oriented programming for the users and provided displays of all the inputs and outputs in the form of GUI-Type. The results of this research will provide the project managers with efficient management tools.

• Journal of Convergence for Information Technology
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• v.9 no.11
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• pp.125-133
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• 2019

In this paper, probabilistic flood risk maps were produced for levee break caused by possible flood scenarios. The results of the previous studies were employed for flood stages corresponding to hydrological extreme event quantified uncertainties and then predicted the location of a levee breach. The breach width was estimated by combining empirical equation considered constant width and numerical modeling considered uncertainties on compound geotechnical component. Accordingly, probabilistic breach outflow was computed and probabilistic inundation map was produced by 100 runs of 2D inundation simulation based on reliability analysis. The final probabilistic flood risk map was produced by combining probabilistic inundation map based on flood hazard mapping methodology. The outcomes of the study would be effective in establishing specified emergency actin plan (EAP) and expect to suggest more economical and stable design index.

• Computers and Concrete
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• v.29 no.4
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• pp.263-278
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• 2022

Limestone calcined clay cement (LC³) is a low carbon alternative to conventional cement. Literature shows that using limestone and calcined clay in LC³ increases the thermal degradation of LC³ pastes and can increase the magnitude of fire risk in LC³ concrete structures. Higher thermal degradation of LC³ paste prompts this study toward understanding the fire performance of LC³ concrete and the associated magnitude of fire risk. For fire performance, concrete prepared using ordinary Portland cement (OPC), pozzolanic Portland cement (PPC) and LC³ were exposed to 16 scenarios of different elevated temperatures (400℃, 600℃, 800℃, and 1000℃) for different durations (0.5 h, 1 h, 2 h, and 4 h). After exposure to elevated temperatures, mass loss, residual ultrasonic pulse velocity (rUPV) and residual compressive strength (rCS) were measured as the residual properties of concrete. XRD (X-ray diffraction), TGA (thermogravimetric analysis) and three-factor ANOVA (analysis of variance) are also used to compare the fire performance of LC³ with OPC and PPC. Monte Carlo simulation has been used to assess the magnitude of fire risk in LC³ structures and devise recommendations for the robust application of LC³. Results show that LC³ concrete has weaker fire performance, with average rCS being 11.06% and 1.73% lower than OPC and PPC concrete. Analysis of 106 fire scenarios, in Indian context, shows lower rCS and higher failure probability for LC³ (95.05%, 2.22%) than OPC (98.16%, 0.22%) and PPC (96.48%, 1.14%). For robust application, either LC³ can be restricted to residential and educational structures (failure probability <0.5%), or LC³ can have reserve strength (factor of safety >1.08).