• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.157-163
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• 2018

This paper describes design improvement to a research rector for safety enhancement using Probabilistic Safety Assessment (PSA). This PSA under reactor design was undertaken to assess the level of safety for the design of a research reactor and to evaluate whether it is probabilistically safe to operate and reliable to use. The scope of the PSA reported here is a Level 1 PSA, which addresses the risks associated with the core damage. The technical objectives of this study were to identify accident sequences leading to core damage and to derive design improvement from the dominant accident sequences through the sensitivity analysis. The AIMS-PSA and FTREX were used for the this PSA of the research reactor. The criterion for inclusion was all sequences with a point estimate frequency greater than a truncation value of 1.0E-14/yr. The final result indicates a point estimate of 6.79E-05/yr for the overall Core Damage Frequency (CDF) attributable to internal initiating events for the research reactor under design. Based on the dominant accident sequences from the PSA, the seven kinds of sensitivity analysis were performed and some design improvement items were derived. When the five methods to improve the safety were all applied to the reactor design and emergency operating procedure, its risk was reduced to about 1.21E-06/yr from 6.79E-05/yr. The contribution of LOCA and LOEP with high CDF were significantly reduced by the sensitivity analysis. The safety of the research reactor was well improved and the risk was reduced than before adapting the design improvement gotten from the sensitivity analysis. The present study indicated that the research reactor has the well-balanced safety in regard to each initiating event contribution to CDF. The PSA methodology is very effective to improve reactor safety in a conceptual design phase and especially, Risk-informed design(RID) is very nice way to find the deficiencies of research reactor under design and to improve the reactor safety by solving them.

• Journal of Internet Computing and Services
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• v.25 no.4
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• pp.97-108
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• 2024

Ethical and technical problems are becoming serious as the industrialization of artificial intelligence robots becomes active, research on risk is insufficient. In this situation, the researcher developed 52 verified indicators that can measure the body, rights, property, and social risk of artificial intelligence robots. In order to develop measurement indicators for each type of risk of artificial intelligence robots, 11 experts were interviewed in-depth after IRB deliberation. IIn addition, 328 workers in various fields where artificial intelligence robots can be introduced were surveyed to verify their fieldwork, and statistical verification such as exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis was verifyed to measure validity and reliability. It is expected that the measurement indicators presented in this paper will be widely used in the development, certification, education, and policies of standardized artificial intelligence robots, and become the cornerstone of the industrialization of artificial intelligence robots that are socially sympathetic and safe.

• 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 Biomedical Engineering Research
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• v.44 no.3
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• pp.190-203
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• 2023

The purpose of this study is to provide basic data to ensure the safety and essential performance of a Lower Extremity robotic assisted gait training system and to provide advanced technology and technical basis to the industry handling the system. Based on IEC 60601-1:2012/AMD2:2020 (Medical Electrical Equipment - General requirements for basic safety and essential performance of medical electrical equipment), IEC 62366-1:2015/AMD1:2020 (Medical devices - Part 1: Application of usability engineering to medical devices) and EN ISO 14971:2019 (Medical devices - Application of risk management to medical devices), the requirements for ensuring the safety and essential performance of the Lower Extremity robotic assisted gait training system were derived. Through the Delphi survey method and scenario analysis, which reflects the opinions and knowledge of experts in the fields of development, testing and review of technical documents, and quality assurance of medical devices, validity and reliability were conducted and obtained results with adequate content validity ratio (CVR; 0.7≤) and excellent reliability (Cronbach's α; 0.9≤). As a result, it was confirmed that the reliability and validity of the risk management process to ensure the safety and essential performance of the Lower Extremity robotic assisted gait training system are required a model can be established to provide measures to reduce risks according to the level of risk exposure caused by usage.

• Earthquakes and Structures
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• v.6 no.1
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• pp.19-43
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• 2014

A risk assessment framework for evaluating building structures is implemented in this study. This framework allows considering sources of uncertainty both on structural capacity and seismic demand. In particular randomness on seismic load, incident angle, material properties, floor mass and structural damping are considered; in addition the choice of fibre modelling versus plastic hinge model is also considered as a source of uncertainty. The main objective of this work is to study the contribution of these sources of uncertainty on the fragilities of steel and steel-reinforced concrete composite 3D building structures. The fragility curves are expressed in the form of a two-parameter lognormal distribution where vertical statistics in conjunction with metaheuristic optimization are implemented for calculating the two parameters.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.25-40
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• 2019

Many companies are executing big data analysis and utilization projects to legitimize the development of new business areas or conversion of management or technical strategies. In Korea and abroad, however, such projects are failing because they are not completed within specified deadlines, which is not unrelated to the current situation in which the knowledge base for big data project risk management from an engineering perspective is grossly lacking. As such, the current study analyzes the risk factors of big data implementation and utilization projects, in addition to finding risk factors that are highly important. To achieve this end, the study extracts project risk factors via literature review, after which they are grouped using affinity methodology and sifted through expert surveys. The deduced risk factors are structuralize using factor analysis to develop a table that categorizes various types of big data project risk factors. The current study is significant that in it provides a basis for developing basic control indicators related to risk identification, risk assessment, and risk analysis. The findings from the study contribute greatly to the success of big data projects, by providing theoretical basis regarding efficient big data project risk management.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.134-136
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• 2019

The International Maritime Organization (IMO) issued 2017 Guidelines on maritime cyber risk management. In accordance with IMO's maritime cyber risk management guidelines, each flag State is required to comply with the Safety Management System (SMS) of the International Safety Management Code (ISM) that the cyber risks should be integrated and managed before the first annual audit following January 1, 2021. In this paper, to identify cyber security management targets and risk factors in the maritime sector and to conduct vulnerability analysis, we catagorized the cyber security sector in management, technical and physical sector in maritime sector based on the industry guidelines and international standards proposed by IMO. In addition, the Risk Matrix was used to conduct a qualitative risk assessment according to risk factors by cyber security sector.

• Information Systems Review
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• v.17 no.1
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• pp.117-140
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• 2015

Cloud Computing has drawn attention as one of 10 IT strategic technology trends and has various advantages such as cost reduction and enhancing business flexibility. However, corporations hesitate to adopt the service because of unexpected risks. Especially compared to large firm, medium and small ones use public cloud that security risk is high. Meanwhile, real option strategy has drawn attention as the method to hedge uncertainty in IT projects. Therefore, in this study causal relationships among technical, security, relational, and economic risks of cloud service will be investigated. Eventually, this study investigates how those risks influence the intention to choose the real option about the cloud service. For this study, five hypotheses is drawn, and a survey is conducted about the medium and small firms which are currently using cloud service to examine hypotheses. Since the study is at organizational level, 287 questionnaire replies are recalculated to 120 firms. For statistical analysis, Smart PLS and SPSS Statistics18 are used. As a result, technical risk of cloud service has significantly positive influence on security risk. Second, security risk and relational risk of cloud service has significantly positive influence on economic risk. Third, economic risk of cloud service has significantly positive influence on the intention to purchase the delay option or abandon option. Based on this result, this research discussed practical and academic implications and the limitations.

• Earthquakes and Structures
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• v.11 no.3
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• pp.505-516
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• 2016

This paper evaluates the scaling of ground motions recorded from nine intermediate-depth earthquakes produced in the Vrancea seismic zone in Romania. The considered ground motion database consists of 363 horizontal recordings obtained on soil classes B and C (according to Eurocode 8). An analysis of the inter- and intra-event spectral accelerations is performed in order to gain information regarding the magnitude and distance scaling of the Vrancea ground motions. The analyses reveal a significant influence of the earthquake magnitude and focal depth on the distance scaling and different magnitude and distance scaling for the two soil classes. A linear magnitude and distance scaling is inferred from the results for the range of magnitudes $5.2{\leq}M_W{\leq}7.1$. The results obtained are checked through stochastic simulations and the influence of the stress drop and kappa values on the ground motion levels is assessed. In addition, five ground motion models which were tested in other studies using recordings from Vrancea earthquakes are analyzed in order to evaluate their corresponding host stress drop and kappa. The results show generally a direct connection between the host kappa values and the host stress drop values. Moreover, all the ground motion models depict magnitude dependent host kappa and stress drop levels.

• The Journal of the Korea Contents Association
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• v.5 no.2
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• pp.107-114
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• 2005

This paper proposes to analyze a security level about information property systems. This method uses objective and quantitative risk level assessment. The method analyzes administrative, physical and technical aspects of information property system commonly. This method also uses administrative, physical and technical weights. Individually according to requirements security assessment purpose. And it shows risks weighting mean and importance of information property by graph. The most right and up systems in maps is prior to other systems. Also, Quantitative analysis presents more objective and efficient results for security level assessment of information system.