• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.64-72
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• 2003

A new reliability assessment methodology is presented and the new method is compared with fault tree analysis. The system is modeled by directed graph at a new methodology, which is composed of nodes and arcs. The directed graph corresponds to the layout of chemical process and is easy to construct. Therefore, the directed graph analysis is applicable to the chemical process that has complex sequence. The example of fault tree analysis and directed graph analysis is given. The directed graph analysis has proved to be a valuable and useful method for the reliability assessment of chemical process.

• School Mathematics
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• v.17 no.2
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• pp.331-353
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• 2015

The purpose of this study is to investigate expertise of mathematic teachers in development of designing assessment items, derived from development of assessing tools, which is a part of assessing competence of mathematic teachers. Analysis was made upon the difference between Pre-service and In-service teachers in terms of self-perception on assessment items. The assessing references of self-perception on developing in designing assessment items consist of followings: one's Beliefs and Self-Rating in designing assessment items. This investigation on self-perception was carried out by both pre-service teachers who are currently enrolled students in college and in-service teachers who are currently incumbent in secondary schools. This analysis based on 310 teachers' answers on self-perception of designing assessment items, both in- and preservice.

• Journal of Korean Elementary Science Education
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• v.18 no.1
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• pp.65-73
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• 1999

The purpose of this study is tile development of tile observation Assessment criteria that is used to assess manipulative skills in elementary science. The procedures of developing observation Assessment criteria are as follows. First, we investigated the actual condition about science process skills assessment with tile questionnaire. Second, we selected 7 experimental apparatus through the analysis of the science textbooks. The selected experimental apparatus are dropper, alcohol lamp, thermometer, test tube, filtering device, able balance, graduated cylinder Third, the observation Assessment criteria arc developed through tile analysis of the related experimental textbooks, the demonstrations, and the questionnaire, Forth, tile validity is verified by science education specialists and graduate students who major in science education. Fifth, the first jilter-rater agreement is investigated in the result of the field with observation criteria of which the validity was verified. The second inter-rater agreement is investigated through the revision and the addition of the criteria with the low agreement. In result, the jilter-rater agreement ranged from 0.86 to 0.98. One of the major problems in observation assessment is the rater's subjective viewpoint. So, this research shows a more specified scale and criteria for the assessment. This suggests that the observation Assessment criteria developed in tile study satisfies the high reliability and validity requirements. Considering the results, this criteria call be used effectively for assessing manipulative skills of elementary school students.

• Journal of Environmental Science International
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• v.23 no.1
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• pp.143-152
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• 2014

The results which are from naturalness assessment and visual assessment was examined to accomplish a classification, a conclusion, a comparison and an analysis. Also statistical test was examined to identify applicability of the survey to other rivers according to the result of visual assessment. As a result of naturalness assessment and visual assessment, evaluation rate of Geumho river is the highest rank of the grade as 2.5. Also t-test was examined to apply items of visual assessment at other rivers through differences in means of river naturalness rates from which visual assessment results. Most of differences in means of river naturalness rates are significant. Thus assessment criteria can be applied to other rivers to find out unique characteristics because each item has independent characteristics.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.104-118
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• 2003

It has been criticized that conventional human reliability analysis (HRA) methodologies for probabilistic safety assessment (PSA) have been focused on the quantification of human error probability (HEP) without detailed analysis of human cognitive processes such as situation assessment or decision-making which are crticial to successful response to emergency situations. This paper introduces a new human reliability analysis (HRA) methodology, AGAPE-ET (A guidance And Procedure for Human Error Analysis for Emergency Tasks), focused on the qualitative error analysis of emergency tasks from the viewpoint of the performance of human cognitive function. The AGAPE-ET method is based on the simplified cognitive model and a taxonomy of influencing factors. By each cognitive function, error causes or error-likely situations have been identified considering the characteristics of the performance of each cognitive function and influencing mechanism of PIFs on the cognitive function. Then, overall human error analysis process is designed considering the cognitive demand of the required task. The application to an emergency task shows that the proposed method is useful to identify task vulnerabilities associated with the performance of emergency tasks.

• Nuclear Engineering and Technology
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• v.52 no.1
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• pp.211-221
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• 2020

One fundamental element of probabilistic safety assessment (PSA) is the initiating event (IE) analysis. Since IE frequencies can change over time, time-trend analysis is required to obtain optimized IE frequencies. Accordingly, such time-trend analyses have been employed to estimate industry-average IE frequencies for use in the PSAs of U.S. nuclear power plants (NPPs); existing PSAs of Korean NPPs, however, neglect such analysis in the estimation of IE frequencies. This article therefore provides the method for and results of estimating Korean industry-average IE frequencies using time-trend analysis. It also examines the effects of the IE frequencies obtained from this study on risk insights by applying them to recently updated internal events Level 1 PSA models (at-power and shutdown) for an OPR-1000 plant. As a result, at-power core damage frequency decreased while shutdown core damage frequency increased, with the related contributions from each IE category changing accordingly. These results imply that the incorporation of time-trend analysis leads to different IE frequencies and resulting risk insights. The IE frequency distributions presented in this study can be used in future PSA updates for Korean NPPs, and should be further updated themselves by adding more recent data.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.719-728
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• 2023

Purpose: Mobile cranes are machines that contribute to high mortality, and the High Risk Factor (SIF) information, which analyzed 2,574 accidental deaths in the construction industry in the past 6 years (2016~2021), resulted in a total of 61 mobile crane accidents. Despite safety measures in the field, it is not used properly. In this study, we present standard risk assessment indicators that contribute to accident prevention. Method: Through expert interviews, fatal accident case analysis, field analysis, and literature research, we present the standard risk assessment index method of the 4M risk assessment method. Result: As a result of analyzing the risk assessment of eight sites, it was concluded that it cannot make a significant contribution to disaster prevention and should be applied as an improvement measure of the Standard Risk Assessment Index Law. Conclusion: Switching to the standard risk assessment index method at construction sites has been proposed to make it easier for health and safety personnel and workers to use, contributing to the reduction of accidents.

• Journal of Environmental Impact Assessment
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• v.22 no.3
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• pp.231-240
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• 2013

The Purpose of this research was to propose positioning strategies of urban park (UP) based on the assessment of location characteristics at cheongju city. To do that, this research found out urban park service area (UPSA) using GIS network analysis and built socio-economic attribute database, UP map, and other public service thematic maps such as public transportation, education, child-care, and convenience services. And this research analyzed spatial and attribute data using Pearson's correlation analysis, multiple linear regression, and binary logistic regression methods. As a result of this analysis, 1) the nearer neighborhood park and children's park, the higher land price and assumption income level (AIL). 2) children's parks were closed to living convenience facilities such as bank, hospital, and convenience store. 3) land price, AIL, population, and other public services level (PSL) in UPSA were higher than that of non-UPSA. 4) The higher land price, AIL, population, and other PSL, the higher urban park service level. The results of this research may contribute to resolve the regional UP unbalance and to improve UP service level as public service.

• Journal of Applied Reliability
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• v.18 no.3
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• pp.260-270
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• 2018

Purpose: The purpose of this study is to evaluate the life of the capsule, which is a core part of the heat storage cooling system. This paper will develop a life test mode that can reproduce environment conditions through the analysis of capsule shrinkage and expansion characteristics. Methods: In order to determine the life test mode of the capsule, this paper analyzed the case of field failures and analyzed the deformation characteristics according to the pressure fluctuation of the capsule. The method to find out whether the field failure and deformation analysis results are consistent is the testing with the construction of the repetition pressure test equipment and the thermal cycle test to reproduce the freezing and thawing characteristics. Results: In this study, failure mode analysis and analysis of freezing and thawing characteristics regarding to the capsule positions were completed. Based on this test & analysis results, this paper have been able to determine the main parameters for determining the life test mode, the freezing and thawing time. Conclusion: Determining the lifetime mode of the capsule can be used to improve the life and performance of the thermal storage system.

• Proceedings of the Safety Management and Science Conference
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• 2013.04a
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• pp.445-456
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• 2013

According to Department of labor guideline "2012-104 (2012.9.26.)" This study is to suggest the basic information and the improvement for the application of risk assessment on a construction site by group interview & survey of construction worker who is the practice of the subject and then numerical analysis about awareness and action plan of Safety and health. The result of group interview and survey of construction worker, most of construction worker feel the danger during the work. Then construction worker analysis results that risk assessment helps to change & raise awareness of safety and reduce an industrial disaster. Easy Safety management activity such as TBM & safety education active will be necessary for safe worksite and then I suggest the TBT(tool box talk) active which combines TBM & safety education.