• Nuclear Engineering and Technology
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• v.29 no.1
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• pp.25-34
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• 1997

This study presents a new approach for expert opinion elicitation process to assess an uncertainty inherent in accident management. The need to work with rare event and limited data in accident management leads analysis to use expert opinions extensively. Unlike the conventional approach using point-valued probabilities, the study proposes the concept of fuzzy probability to represent expert opinion. The use of fuzzy probability has an advantage over the conventional approach when an expert's judgment is used under limited dat3 and imprecise knowledge. The study demonstrates a method of combining and propagating fuzzy probabilities. finally, the proposed methodology is applied to the evaluation of the probability of a bottom head failure for the flooded case in the Peach Bottom BWR nuclear power plant.

• Nuclear Engineering and Technology
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• v.35 no.4
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• pp.318-335
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• 2003

Expert judgment is frequently employed in the search for the solution to various engineering and decision-making problems where relevant data is not sufficient or where there is little consensus as to the correct models to apply. When expert judgments are required to solve the underlying problem, our main concern is how to formally derive their technical expertise and their personal degree of familiarity about the related questions. Formal methods for gathering judgments from experts and assessing the effects of the judgments on the results of the analysis have been developed in a variety of ways. The most important interest of such methods is to establish the robustness of an expert's knowledge upon which the elicitation of judgments is made and an effective trace of the elicitation process as possible as one can. While the resultant expert judgments can remain to a large extent substantiated with formal elicitation methods, their applicability however is often limited due to restriction of available resources (e.g., time, budget, and number of qualified experts, etc) as well as a scope of the analysis. For this reason, many engineering and decision-making problems have not always performed with a formal/structured pattern, but rather relied on a pertinent transition of the formal process to the simplified approach. The purpose of this paper is (a) to address some insights into the balanced use of formally structured and simplified approaches for the explicit use of expert judgments under resource constraints and (b) to discuss related decision-theoretic issues.

• Nuclear Engineering and Technology
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• v.46 no.5
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• pp.619-632
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• 2014

The Best Estimate Plus Uncertainty (BEPU) method has been widely used to evaluate the uncertainty of a best-estimate thermal hydraulic system code against a figure of merit. This uncertainty is typically evaluated based on the physical model's uncertainties determined by expert judgment. This paper introduces the application of data assimilation methodology to determine the uncertainty bands of the physical models, e.g., the mean value and standard deviation of the parameters, based upon the statistical approach rather than expert judgment. Data assimilation suggests a mathematical methodology for the best estimate bias and the uncertainties of the physical models which optimize the system response following the calibration of model parameters and responses. The mathematical approaches include deterministic and probabilistic methods of data assimilation to solve both linear and nonlinear problems with the a posteriori distribution of parameters derived based on Bayes' theorem. The inverse problem was solved analytically to obtain the mean value and standard deviation of the parameters assuming Gaussian distributions for the parameters and responses, and a sampling method was utilized to illustrate the non-Gaussian a posteriori distributions of parameters. SPACE is used to demonstrate the data assimilation method by determining the bias and the uncertainty bands of the physical models employing Bennett's heated tube test data and Becker's post critical heat flux experimental data. Based on the results of the data assimilation process, the major sources of the modeling uncertainties were identified for further model development.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.823-832
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• 2006

The Purpose of Similarity(Reproduction) Degree Appraisal is to determine the equality or similarity between two programs and it is a system that presents the technical grounds of judgment which is necessary to support the resolution of software intellectual property rights through expert eyes. The most important things in proceeding software appraisal are not to make too much of expert's own subjective judgment and to acquire the accurate-appraisal results. However, up to now standard research and development for its systematic techniques are not properly made out and as different expert as each one could approach in a thousand different ways, even the techniques for software appraisal types have not exactly been presented yet. Moreover, in the analyzing results of all the appraisal cases finished before, through a practical way, we blow that there are some damages on objectivity and accuracy in some parts of the appraisal results owing to the problems of existing appraisal procedures and techniques or lack of expert's professional knowledge. In this paper we present the model for the standardization of software-similarity-appraisal techniques and objective-evaluation methods for decreasing a tolerance that could make different results according to each expert in the same-evaluation points. Especially, it analyzes and evaluates the techniques from various points of view concerning the standard appraisal process, setting a range of appraisal, setting appraisal domains and items in detail, based on unit processes, setting the weight of each object to be appraised, and the degree of logical and physical similarity, based on effective solutions to practical problems of existing appraisal techniques and their objective and quantitative standardization. Consequently, we believe that the model for the standardization of software-similarity-appraisal techniques will minimizes the possibility of mistakes due to an expert's subjective judgment as well as it will offer a tool for improving objectivity and reliability of the appraisal results.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.313-319
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• 1997

There is currently a focus on usability of interactive computer software. Previous research in software ergonomics has indicated the importance of evaluating the usability of software user interfaces. Software developers, interface designers or human foctors engineers often confront the task of comparative evaluation among systems, versions or interface designs. This study presents a structured model for comparative evaluation of user interface designs using usability criteria and measures. The proposed model consists of twomain phases : the prescreening phase ad the evaluation phase. The first phase involves expert judgment-based approach with qualitative criteria. The prescreening phase uses absolute measurement analytic hierarchy process to filter possible altermative interfaces to a reasonable subset. The second phase involves user-based approach such as usability testing, with quantitative criteria. The objective of the evaluation phase is to evaluate a subset of altermatives using objective measures. A set of criteria and measures for evaluating the usability of computer software designs is presented. The proposed model provides practitioners with a structured approach to select the best interface based on usability criteria and measures.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2003.05a
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• pp.338-346
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• 2003

Information Technology (IT) and the internet have been major drivers the changes in all aspects of the business processes and activities. They have brought major changes to the financial statements audit environment as well, which in turn has required modifications in audit procedures. There exist, however, certain difficulties with current audit procedures especially for the assessment of the level of control risk. This assessment is primarily based on the auditors' professional judgment and experiences, not based on the objective hies or criteria. To overcome these difficulties, this paper proposes a prototype decision support model named CRAS-CBR using case based reasoning (CBR) to support auditors in making their professional judgment on the assessment of the level of control risk of the general accounting system in the manufacturing industry. To validate the performance, we compare our proposed model with benchmark performances in terms of classification accuracy for the level of control risk. Our experimental results showed CRAS-CBR outperforms a statistical model (MDA) and staff auditor performance in average hit ratio.

• Korea journal of population studies
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• v.33 no.1
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• pp.161-189
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• 2010

Dealing with uncertainty has been a critical issue in demographic and population forecasting since 1980. This study reviews methodological developments in demographic and population forecasting over the last several decades. First, this study reviews the important issue of the uncertainty surrounding demographic forecasts. Several limitations of the traditional scenario approach to dealing with uncertainty are also discussed. Second, in forecasting demographic processes such as mortality, fertility, and migration, three approaches of stochastic forecasting are identified and discussed: expert judgment, statistical modeling, and analysis of historical forecast errors. Finally, this study discusses the current issues and directions for future research in stochastic demographic forecasting.

• Journal of Korean Critical Care Nursing
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• v.10 no.3
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• pp.41-52
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• 2017

Purpose : This concept analysis identified attributes and defined triage competency among emergency nurses. Method : Walker and Avant's approach was used to guide the concept analysis. A literature review was completed including 26 studies, 5 reports of related associations, and 5 books. Results : The concept of triage competency in emergency nurses was identified as five attributes: clinical judgment, expert assessment, management of medical resources, timely decision, and communication. Antecedents of the concept were triage education and emergency room experience. The consequences of the concept were efficiency of care, patient rating, and safety. Triage competency in emergency nurses was defined as the comprehensive ability to prioritize patients' urgency and allocate limited medical resources. Conclusion : This study is meaningful since it clarified triage competency among emergency nurses. The attributes and empirical indicators of this study will likely lay the foundation for development of triage competency metrics.

• Nuclear Engineering and Technology
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• v.34 no.4
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• pp.331-343
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• 2002

We performed an importance analysis of In-Service Testing (157) components for Ulchin Unit 3 using the integrated evaluation method for categorizing component safety significance developed in this study. The developed method is basically aimed at having a PSA expert perform an importance analysis using PSA and its related information. The importance analysis using the developed method is initiated by ranking the component importance using quantitative PSA information. The importance analysis of the IST components not modeled in the PSA is performed through the engineering judgment, based on the expertise of PSA, and the quantitative and qualitative information for the 157 components. The PSA scope for importance analysis includes not only Level 1 and 2 internal PSA but also Level 1 external and shutdown/low power operation PSA. The importance analysis results of valves show that 167 (26.55%) of the 629 IST valves are HSSCs and 462 (73.45%) are LSSCs. Those of pumps also show that 28 (70%)of the 40157 pumps are HSSCs and 12 (30%) are LSSCs.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.3
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• pp.63-68
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• 2007

The LRA(Logistic Regression Analysis) conducts a quantitative analysis by collecting a lot of samples and the AHP(Analytic Hierarchy Program) makes use of expert decision influenced by subjective judgment to a certain degree. This study is to suggest a combination method in mapping landslide hazard by giving equal weight for the result of LRA and AHP. Topographic factors(slope, aspect, elevation), soil dram, soil depth and land use were adopted to classify landslide hazard areas. The three methods(LRA, AHP, the combined approach) was applied to a $520km^2$ region located in the middle of South Korea which have occurred 39 landslides during 1999 and 2003. The suggested method showed 58.9% matching rate for the real landslide sites comparing with the classified areas of high-risk landslide While LRA and AHP Showed 46.1% and 48.7% matching rates respectively. Further studies are recommended to find the optimal combining weight of LRA and AHP with more landslide data.