• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.1
• /
• pp.58-65
• /
• 2008

Reliability-Centered Maintenance plan for maintenance schedule of generating unit is being assessed in this paper. Maintenance schedule is a key index that can be used to determine stability and cost. In this paper, stochastic FMECA is described for the life assessment by using probability distribution, and combustion-turbine generations in Korean power systems have been assessed for maintenance schedule. Such an assessment can be a useful guide for maintenance plans in restructured power industry.

• Nuclear Engineering and Technology
• /
• v.48 no.1
• /
• pp.43-54
• /
• 2016

In the present paper, development of the three-dimensional (3D) computational code based on Galerkin finite element method (GFEM) for solving the multigroup forward/adjoint diffusion equation in both rectangular and hexagonal geometries is reported. Linear approximation of shape functions in the GFEM with unstructured tetrahedron elements is used in the calculation. Both criticality and fixed source calculations may be performed using the developed GFEM-3D computational code. An acceptable level of accuracy at a low computational cost is the main advantage of applying the unstructured tetrahedron elements. The unstructured tetrahedron elements generated with Gambit software are used in the GFEM-3D computational code through a developed interface. The forward/adjoint multiplication factor, forward/adjoint flux distribution, and power distribution in the reactor core are calculated using the power iteration method. Criticality calculations are benchmarked against the valid solution of the neutron diffusion equation for International Atomic Energy Agency (IAEA)-3D and Water-Water Energetic Reactor (VVER)-1000 reactor cores. In addition, validation of the calculations against the $P_1$ approximation of the transport theory is investigated in relation to the liquid metal fast breeder reactor benchmark problem. The neutron fixed source calculations are benchmarked through a comparison with the results obtained from similar computational codes. Finally, an analysis of the sensitivity of calculations to the number of elements is performed.

• Journal of the Korean Society of Safety
• /
• v.38 no.1
• /
• pp.9-17
• /
• 2023

In this study, we aimed to identify the important hazard factors and determine their criticality in causing serious accidents in vehicle-mounted mobile elevated work platforms (MEWPs). Fuzzy failure modes and effects analysis (FMEA)was performed using accident data and a survey of experts. To determine the hazard factors, the accident data for the last 10 years were used and a questionnaire survey was designed. The questionnaire survey was sent to four experts in the field of occupational safety to determine the severity, occurrence, and detectability of serious accidents in MEWPs. Furthermore, objective RPN scores and risk priority were obtained using fuzzy FMEA. Finally, the criticality of hazard factors in descending order was found to be overloading, non-installation or defective installation of outriggers, breakage due to wire rope aging, and illegal remodeling of vehicle structures. The results were verified by comparing the occurrence data of serious disasters.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.4
• /
• pp.2837-2843
• /
• 2015

This study firstly finds the factors for positive development of urban regeneration cases from the point of view of a public sector, and then analyzes the development potential of Urban Regeneration Projects in Gyeonggi-do through the methodology able to measure the development potential objectively. The process to analyze the development potential is as follows. First, after finding indices through literature review, indices with redundancy and similarity are drawn by the discussion with relative experts. Second, four clusters and twelve indices are drawn by the verification of experts. Finally, criticality analysis of indices are analyzed by ANP. According to the result to apply criticality analysis of indices to urban regeneration cases, factors related to residential environment and local economy influence development potential more than those related to infrastructures and land-use.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.25 no.2
• /
• pp.45-59
• /
• 2023

This study aims to find implications for the introduction and practice of ESG by domestic fashion companies by examining the core ESG topics and strategies of Samsung C&T Fashion Division, Kolon FnC, F&F holdings, and Fila. ESG management analysis examined the importance of the criticality evaluation process, critical issues, and implementation strategies for each key topic based on the company's 2021 ESG sustainable management report, and analyzed the relationship with UN SDGs and the GRI. The analysis results are as follows: As for KCGS' ESG rating, Samsung C&T's fashion division, Kolon FnC, and Fila Holdings were rated A, while F&F Holdings was rated B+. The major issues derived from ESG's criticality assessment are environmental issues related to Samsung C&T's fashion division. Kolon FnC was found to have focused on the social sector and F&F Holdings focused on governance structure. After examining the correlation between the ESG core strategies of the investigated fashion companies and the 17 SDGs, the common areas were identified as quality employment, sustainable production and consumption, and climate changes and response. Correlation with the GRI Standards 2021 Index, (GRI 1, GRI 11, and GRI 12 created in 2021) was not reflected. In the future, it will be necessary to have a transparent governance structure that meets global standards, sets measurable goals, and continuously manages them. Other companies should also recognize ESG management processes that embrace various stakeholders and strengthens win-win cooperation to manage risks, and establish mid- to long-term response strategies.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.13 no.6
• /
• pp.305-312
• /
• 2018

Software has been used to develop many functions of the modern weapon systems which has a high mission criticality. Weapon system software must consider multi-threaded processing to satisfy growing performance requirement. However, developing multi-threaded programs are difficult because of concurrency faults, such as unintended data races. Especially, it is important to prepare analysis for debugging the data races, because the weapon system software may cause personal injury. In this paper, we present an efficient framework of analysis, called ConDeWS, which is designed to determine the scope of dynamic analysis through using the result of static analysis and fault analysis. As a result of applying the implemented framework to the target software, we have detected unintended data races that were not detected in the static analysis.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.1481-1486
• /
• 2008

To apply more effective the RCM analysis for railway vehicle, the maintenance cost per equipment should be considered together with failure criticality per equipment considered in existing. This paper is described the systematic calculation of maintenance cost considering the RCM analysis of railway vehicle. To calculate the maintenance cost systematically, the cost breakdown structure was established, and basic cost information and calculated cost items were defined. In addition, the linking between calculated cost and RCM analysis was considered. In future, this proposal would be used to analysis of cost effectiveness through RCM analysis of railway vehicle.

• Nuclear Engineering and Technology
• /
• v.50 no.1
• /
• pp.18-24
• /
• 2018

This study proposes a new method of analyzing the burnup credit in boiling water reactor spent fuel assemblies against various operating parameters. The operating parameters under investigation include fuel temperature, axial burnup profile, axial moderator density profile, and control blade usage. In particular, the effects of variations in one and two operating parameters on the curve of effective multiplication factor ($k_{eff}$) versus burnup (B) are, respectively, the so-called single and compound effects. All the calculations were performed using SCALE 6.1 together with the Evaluated Nuclear Data Files, part B (ENDF/B)-VII238-neutron energy group data library. Furthermore, two geometrical models were established based on the General Electric (GE)14 $10{\times}10$ boiling water reactor fuel assembly and the Generic Burnup-Credit (GBC)-68 storage cask. The results revealed that the curves of $k_{eff}$ versus B, due to single and compound effects, can be approximated using a first degree polynomial of B. However, the reactivity deviation (or changes of $k_{eff}$, ${\Delta}k$) in some compound effects was not a summation of the all ${\Delta}k$ resulting from the two associated single effects. This phenomenon is undesirable because it may to some extent affect the precise assessment of burnup credit. In this study, a general formula was thus proposed to express the curves of $k_{eff}$ versus B for both single and compound effects.

• Journal of the Korean Dietetic Association
• /
• v.22 no.3
• /
• pp.193-213
• /
• 2016

The purpose of this study is to provide a standard job description for a nutrition teacher placed in primary and secondary schools by analyzing their duties. DACUM is an acronym for 'Developing A CUrriculuM'. It was used by experts to determine the job duties, tasks and task elements to establish the job descriptions of a nutrition teachers through the development of a DACUM chart. An expert panel consisting of 10 nutrition teachers participated in a DACUM workshop and derived nutrition teacher's DACUM chart. A total of 1,550 nutrition teachers across the country were targeted as the survey subjects for validation of the DACUM chart through their perception of the frequency, importance, and difficulty of each item in the job description. A tree structure, criticality analysis, and contents validity index were added for verification. The definition of the nutrition teacher's job and DACUM chart with 5 duties, 28 tasks, and 107 task elements were derived by the DACUM method. The definition of a nutrition teacher was 'A teacher who is responsible for food service management and nutrition education and counseling for health promotion and disease prevention for students in primary and secondary schools'. The validation results of the tree structure were the priorities of the 28 tasks with ranks 1 and 2. Because there was no third priority, it was considered to be a good representation of the tasks of nutrition teachers. The DACUM chart was found to be evenly distributed with relative importances of more than 17 or less than 11 through the criticality analysis. Since the C5-4 (Conduct simulation exercise against food poisoning)'s content validity index was significantly less than the reference value of 0.78, it was not included in the final job description. 5 duties, 28 tasks, 102 task elements were included in the final job description of a nutrition teacher.

• Journal of Digital Convergence
• /
• v.11 no.11
• /
• pp.15-27
• /
• 2013

The purpose of this study is to develop the evaluation system of which the city safety can be realized in the U-City. The evaluation system on "how much safe the present city is" and "how much safe it will be in the future" has been selected and the criticality has also been analyzed. The result of criticality analysis is that the indicator for "how safe the current city is" showed that the disaster prevention and environmental field are important. In the future, the indicator of possibility for the U-safe city should be prepared by the imtegrative operation management system, and on the basis of this, it also showed that the necessary indicator to build the system for keeping the safe city is important. The evaluation system for the U-safe city, hereafter, can be utilized for the city plan, construction, operation, and management utilized by IT in local government.