• Wind and Structures
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• v.15 no.2
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• pp.131-145
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• 2012

Severe wind is one of the major natural hazards in Australia. The component contributors to economic loss in Australia with regards to severe wind are tropical cyclones, thunderstorms and subtropical (synoptic) storms. Geoscience Australia's Risk and Impact Analysis Group (RIAG) is developing mathematical models to study a number of natural hazards including wind hazard. This paper discusses wind hazard under current and future climate conditions using RIAG's synoptic wind hazard model. This model can be used in non-cyclonic regions of Australia (Region A in the Australian-New Zealand Wind Loading Standard; AS/NZS 1170.2:2011) where the wind hazard is dominated by synoptic and thunderstorm gust winds.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.241-247
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• 2001

A Fire Safety Evaluation Module(FSEM), which quantitatively evaluates the risk of evacuees when fire occurs in buildings or ships, is presented in this paper. The developed FSEM can be applied to multi-room structure. Basic input data for the FSEM are prepared by fire model and evacuation model. CFAST which is one of the existing fire models is used as fire model and MonteDEM evacuation model was developed for evacuation model, respectively. MonteDEM evacuation model makes use of distinct element method and Monte-Carlo simulation, and it can also take into consideration ground inclination by ship motions in order to simulate the real situation of evacuation. Some typical situations are modelled for illustrative examples and quantitative assessment of evacuee's risk under fire accident is carried out.

• Korean Management Science Review
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• v.31 no.1
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• pp.49-61
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• 2014

We investigate the hedging effectiveness of incorporating single-stock futures into the corresponding stocks. Investing in only stocks frequently causes too much risk when market volatility suddenly rises. We found that single-stock futures help reduce the variance and risk levels of the corresponding stocks invested. We use daily prices of Korean stocks and their corresponding futures for the time period from December 2009 to August 2013 to test the hedging effect. We also use system trading technique that uses automatic trading program which also has several simulation functions. Moving average strategy, Stochastic's strategy, Larry William's %R strategy have been considered for hedging strategy of the futures. Hedging effectiveness of each strategy was analyzed by percent reduction in the variance between the hedged and the unhedged variance. The results clearly showed that examined hedging strategies reduce price volatility risk compared to unhedged portfolio.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.11
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• pp.558-565
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• 2000

In this paper, we propose a method for mitigating for mitigating the effect of voltage of voltage sag in radial power distribution systems using load transfer switching (LTS). The term of LTS is defined that the weakness load points for voltage sag transfer to the alternative source during the fault clearing practices. The sequenced of proposed LTS method is divided into the search of weakness points for voltage sag using the risk assessment model and transfer behavior of weakness points. The search of weakness point is carried out using the risk assessment model of voltage sag and Monte Carlo simulation method and the historical reliability data in Korea Electric Power Corporation (KEPCO) are also used. Through the case studies, we verify the effectiveness of proposed LTS method and present the searching method of effective application points of LTS method using the risk assessment model.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.600-605
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• 2007

In this study, the risk rates of different contamination sources of the Foreign material in a minienvironment were analyzed through CFD simulation. From the results, the ambient contamination sources mainly affect wafers in the FOUP, whereas the internal contamination sources mainly affect wafers laid on the robot arm in the minienvironment. And the purging plenum system is very useful in protecting the wafers in the FOUP from Foreign materials transferred from the FFU. However, this system is unable to protect the wafers on the robot arm from internal Foreign materials and the wafers in the FOUP from sources of the interface between the FOUP and the minienvironment.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.95-108
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• 2005

The purpose of this study is to develop the ITS evaluation model using the Probabilistic Risk Analysis (PRA) methodology and to demonstrate the goodness-of-fit of the large ITS projects through the comparative analysis between DEA and PRA model. The results of this study are summarized below. First, the evaluation mode] using PRA with Monte-Carlo Simulation(MCS) and Latin-Hypercube Sampling(LHS) is developed and applied to one of ITS projects initiated by local government. The risk factors are categorized with cost, benefit and social-economic factors. Then, PDF(Probability Density Function) parameters of these factors are estimated. The log-normal distribution, beta distribution and triangular distribution are well fitted with the market and delivered price. The triangular and uniform distributions are valid in benefit data from the simulation analysis based on the several deployment scenarios. Second, the decision making rules for the risk analysis of projects for cost and economic feasibility study are suggested. The developed PRA model is applied for the Daejeon metropolitan ITS model deployment project to validate the model. The results of cost analysis shows that Deterministic Project Cost(DPC), Deterministic Total Project Cost(DTPC) is the biased percentile values of CDF produced by PRA model and this project need Contingency Budget(CB) because these values are turned out to be less than Target Value(TV;85% value), Also, this project has high risk of DTPC and DPC because the coefficient of variation(C.V) of DTPC and DPC are 4 and 15 which are less than that of DTPC(19-28) and DPC(22-107) in construction and transportation projects. The results of economic analysis shows that total system and subsystem of this project is in type II, which means the project is economically feasible with high risk. Third, the goodness-of-fit of PRA model is verified by comparing the differences of the results between PRA and DEA model. The difference of evaluation indices is up to 68% in maximum. Because of this, the deployment priority of ITS subsystems are changed in each mode1. In results. ITS evaluation model using PRA considering the project risk with the probability distribution is superior to DEA. It makes proper decision making and the risk factors estimated by PRA model can be controlled by risk management program suggested in this paper. Further research not only to build the database of deployment data but also to develop the methodologies estimating the ITS effects with PRA model is needed to broaden the usage of PRA model for the evaluation of ITS projects.

• Journal of Ocean Engineering and Technology
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• v.22 no.5
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• pp.119-125
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• 2008

Musculoskeletal disorders(MSDs) are one of the major issues in shipbuilding industry. Main risk factors of MSDs include manual handling of heavy weight, awkward posture, repetitive tasks, prolonged static muscle contraction, and so on. in this study, Using the three-dimensional digital human modeling and simulation method we made up a worker and work posture on a virtual environment. To verify this simulation we compared both traditional ergonomic analysis on a real worker and digital program analysis on a digital human. And this paper shows that it is possible to reduce the rate of MSDs in the shipbuilding industry because it means we can change poor posture mid surroundings into better ones.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.340-345
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• 2001

Electric power market in Japan is now on the trend of deregulation and privatization just like in Europe and the United States. And various approaches for risk management have been investigated taking the electric power price fluctuation after the deregulation into account. The behavior of the investment in power generation plants has not, however, been studied in detail yet due to the complexity of the problem. The problem of the investment in the deregulated power market is that of autonomous decentralized decision-making system, which includes various kinds of decision-makers, that is, power producers called IPPS Each generator has its own criteria for plant investment. Therefore, the total behavior of the decentralized power market will be so complicated, and normative approach will not be applicable fur this analysis. We have developed a simulation-based system fur behavioral analysis and also the framework design of the decentralized power market.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1917-1922
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• 2010

Near-Field Communication (NFC) is a short-range wireless communication technology evolved from RFID especially for the exchange of data between active and passive devices. This paper presents the mathematical models for the signal path of a NFC transceiver system and a behavioral simulation platform using MATLAB simulink. The approximated mathematical models simplify the simulation complexity of a transceiver and provide a quick evaluation. With this calculation platform, we can evaluate the system performance caused by the noise and the non-linearity of the individual blocks, and caused by system variables such as Effective Number of Bits (ENOB) of ADC and filter cutoff frequency. This platform provides us with a rapid prototyping, a reliable system design, and an efficient risk management during development of the NFC transceiver ICs.

• Korean System Dynamics Review
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• v.12 no.1
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• pp.39-57
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• 2011

This paper is the result of simulation modeling concerning high-level radioactive waste repository(HLRWR) and people's mind for the facility. We describe a procedure of simulation modeling for resident's policy acceptance and perceived risk of HLRWR facility by using System Dynamics approach. To Complete some complicated works, we made the 20 pieces of stock-flow diagrams based on the causal loop diagram that is a blue print of whole variables and relations. The simulation outputs clearly show that cental government efforts to siting the HLRWR will be failed if nothing to give for the region's residents. On the contrary, a monetary incentive and a regional development program help to turn this gloomy situation into a desirable and acceptable condition dramatically. Government has to prepare the schemes considering the HLRWR acceptance and total supporting program including the cash and local development programs.