• 대한산업공학회지
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• 제42권2호
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• pp.151-164
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• 2016

In this paper, we deal with a risk analysis for an IPS (Integrated power system) and propose a simulation model combining the fault tree and event tree in order to estimate the system availability and risk level, together. Firstly, the basic information such as operational scenarios, physical structure, safety systems is explained in order to make the fault tree and event tree of the IPS. Next, we propose a discrete-event simulation model using a next-event time advance technique to advance the simulation time. Also the state transition and activity diagrams are explained to represent the relationship between the objects. By numerical examples, the redundancy allocation is considered in order to decrease the risk level of the IPS.

• 대한산업공학회지
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• 제28권1호
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• pp.44-56
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• 2002

For the risk analysis and risk assessment techniques to be effectively applied to the field of information technology (IT) security, it is necessary that the required activities and specific techniques to be applied and their order of applications are to be determined through a proper risk management model. If the adopted risk management model does not match with the characteristics of host organization, an inefficient management of security would be resulted. In this paper, a risk management model which can be well adapted to Korean domestic IT environments is proposed for an efficient security management of IT. The structure and flow of the existing IT-related risk management models are compared and analysed, and their common and/or strong characteristics are extracted and incorporated in the proposed model in the light of typical threat types observed in Korean IT environments.

• 한국도로학회논문집
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• 제14권6호
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• pp.93-101
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• 2012

PURPOSES : This study is to develop ISM for potential risk factor in School Zone. METHODS : Based on the literature review, the Analytic Hierarchy Process (AHP) has been used most widely. However, it is difficult to apply in practice because the AHP results have the characteristics of the independence between each element and the interlayer can not explain the interrelationship. The Network Analysis Process (ANP) is possible to analyze the relationship between the elements and the network through the feedback. But, the reliability of the analysis fall because of complicated pair of comparison, also it is difficult to solve the super matrix. In this study, the complicated relationship between each element is inquired through the Interpretive Structural Modeling (ISM). RESULTS : The methodology of ISM is developed to remove the children's potential risk factors in school zone. CONCLUSIONS : It is possible to remove the children's potential risk factors from low level to high level step by step and improve safety. Through this, risk factors can be removed from the low-level, and upper-level will automatically improve.

• 국제강구조저널
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• 제18권5호
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• pp.1710-1722
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• 2018

Investigating remained damages from terrible earthquakes, it could be concluded that some events including explosion because of defect and failure in the building mechanical facilities or caused by gas leak, firing, aftershocks, etc., which are occurred during or a few time after the earthquake, will increase the effects of damages. In this paper, by introducing a complete risk analysis which included direct and indirect risks for earthquake (the main shock) and aftershock, the corresponding robustness index was created that called as "robustness index sequential critical events risk-based". One of the main properties of the intended robustness index is using progressive collapse percentage in its evaluation. Then, in a numerical example for a 4-storey moment resisting steel frame structure, a method is presented for obtaining all effective parameters in robustness index evaluation based on the intended risk and at last its results were reported.

• 한국안전학회지
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• 제20권4호
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• pp.71-77
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• 2005

There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as foundation, erection, structure, equipment finish and etc based on accident examples and investigation on actual condition in building. In addition, the safety management system was developed to perform risk assessment of construction and use it for effective safety training for labor.

• 한국안전학회지
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• 제37권5호
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• pp.22-32
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• 2022

The domestic smart factory is being built and spread rapidly, mainly by mid-sized companies and large enterprises according to the government's active introduction and support policy. But these factories only promote production system and efficiency, so harmfulness and risk factors are not considered. Therefore, to derive harmful risk factors in terms of industrial safety for 12,983 government-supported smart factory workplaces from 2014 to 2019, industrial accident status analysis compared workplaces with automation facilities and government-supported workplaces with automation facilities. Also, to reduce risks associated with domestic smart factory processes, twenty government-supported workplaces with automation facilities underwent analysis, evaluating risks through a status survey using the process evaluation table. In addition, the status survey considered region, size, industry, construction level, and accident rate; the difference in risk according to the structure of the process was confirmed. Based on the smart factory process evaluation results, statistical analysis confirmed that serial, parallel, and hybrid structures pose different risk levels and that the risks of mixed structures are greater. Finally, safety control system application was presented for risk assessment and reduction in the smart factory process, reflecting the results of disaster analysis and actual condition investigation.

• 한국지진공학회논문집
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• 제20권7_spc호
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• pp.485-494
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• 2016

The risk-based assessment, also called time-based assessment of structure is usually performed to provide seismic risk evaluation of a target structure for its entire life-cycle, e.g. 50 years. The prediction of collapse probability is the estimator in the risk-based assessment. While the risk-based assessment is the key in the performance-based earthquake engineering, its application is very limited because this evaluation method is very expensive in terms of simulation and computational efforts. So the evaluation database for many archetype structures usually serve as representative of the specific system. However, there is no such an assessment performed for building stocks in Korea. Consequently, the performance objective of current building code, KBC is not clear at least in a quantitative way. This shortcoming gives an unresolved issue to insurance industry, socio-economic impact, seismic safety policy in national and local governments. In this study, we evaluate the comprehensive seismic performance of an low-rise residential buildings with discontinuous structural walls, so called piloti-type structure which is commonly found in low-rise domestic building stocks. The collapse probability is obtained using the risk integral of a conditioned collapse capacity function and regression of current hazard curve. Based on this approach it is expected to provide a robust tool to seismic safety policy as well as seismic risk analysis such as Probable Maximum Loss (PML) commonly used in the insurance industry.

• Earthquakes and Structures
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• 제12권6호
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• pp.653-663
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• 2017

A seismic margin assessment evaluates how much margin exists for the system under beyond design basis earthquake events. Specifically, the seismic margin for the entire system is evaluated by utilizing a systems analysis based on the sub-system and component seismic fragility data. Each seismic fragility curve is obtained by using empirical, experimental, and/or numerical simulation data. The systems analysis is generally performed by employing a fault tree analysis. However, the current practice has clear limitations in that it cannot deal with the uncertainties of basic components and accommodate the newly observed data. Therefore, in this paper, we present a Bayesian-based seismic margin assessment that is conducted using seismic fragility data and fault tree analysis including Bayesian inference. This proposed approach is first applied to the pooltype nuclear research reactor system for the quantitative evaluation of the seismic margin. The results show that the applied approach can allow updating by considering the newly available data/information at any level of the fault tree, and can identify critical scenarios modified due to new information. Also, given the seismic hazard information, this approach is further extended to the real-time risk evaluation. Thus, the proposed approach can finally be expected to solve the fundamental restrictions of the current method.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.140-141
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• 2015

Although the depression of oversea construction market becomes more serious recent years, asian construction market is relatively dynamic, particularly in china. However, few research has been conducted about how to manage construction projects in china as foreign developers. Four important risks are identified from series of surveys using the WBS-RBS method, the result shows that the main risk of tender stage is 'Tender max price error', ' Bill of quantities error', 'Unusual low price' and 'Moral risk' respectively.

• 대한조선학회논문집
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• 제41권3호
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• pp.41-48
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• 2004

Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, the analysis on ship's collision causes are very important to prepare countermeasures which will ensure the safe navigation. This study analysed the ship's collision data over the past 10 years(1991-2000), which is compiled by Korea Marine Accidents Inquiry Agency. The analysis confirmed that ‘ship's collision' is occurred most frequently and the cause is closely related with human factor. The main purpose of this study is to propose risk control measures of ship's collision. For this, the structure of human factor is analysed by the questionnaire methodology. Marine experts were surveyed based on major elements that were extracted from the human factor affecting to ship's collision. FSM has been widely adopted in modeling a dynamic system which is composed of human factors. Then, the structure analysis on the causes of ship's collision are performed using FSM. This structure model could be used in understanding and verifying the procedure of real ship's collision. Furthermore it could be used as the model to prevent ship's collision and reduce marine accidents.