• KEPCO Journal on Electric Power and Energy
• /
• v.7 no.1
• /
• pp.125-128
• /
• 2021

This paper presents the root cause failure analysis of the circulating water pump in the 560 MW thermal power plant. A fractured austenitic stainless-steel shaft operated for 24 years was examined. Fracture morphology was investigated by micro and macro-fractographic analysis. The metallurgical analyses including chemical analysis, metallography and hardness testing were performed. The analysis reveals that the pump shaft was fractured due to the reverse bending load with combination of rotating bending load. Corrective actions for plant operator was recommended based on the analysis.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2002.05a
• /
• pp.144-151
• /
• 2002

In order to examine universal desist I have developed two analytical methodologies based on 3P(point) task analysis: structured task analysis and task matrix analysis. I also extracted me universal design items, namely (1) adjustment (2) redundancy, (3) specification and function transparency, (4) feedback and (5) error tolerance, (6) effective acquisition of information, (7) ease of understanding and judgment (8) comfortable operation, and (9) continuity of information and operation. Structured task analysis is used to uncover problems in each of the tasks constituting a job for each functionally challenged condition of users, and solutions to the extracted problems are examined in terms of the above-mentioned nine universal design items. Task matrix analysis calls for the production of a table for each task in a job. In each table, nine items from the columns, and the horizontal rows list all disability types. Then, solutions are formulated for each cell formed by the intersecting columns and rows. Using these two analysis methods, T have conducted a verification experiment for the universal design of a public bus. The results of the research have enabled me to propose various solutions from a system-based perspective, instead of coming up with the superficial and isolated solutions which are normally produced when conventional analytical methods are used.

• Journal of the Korea Convergence Society
• /
• v.9 no.2
• /
• pp.251-257
• /
• 2018

As the use of big data is necessary for increasing business value, the size of the big data market is getting bigger. Accordingly, it is important to apply competitive patents in order to gain the big data market. In this study, we conducted the patent analysis based keyword network to analyze the trend of big data patents. The analysis procedure consists of big data collection and preprocessing, network construction, and network analysis. The results of the study are as follows. Most of big data patents are related to data processing and analysis, and the keywords with high degree centrality and between centrality are "analysis", "process", "information", "data", "prediction", "server", "service", and "construction". we expect that the results of this study will offer useful information in applying big data patent.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.22 no.4
• /
• pp.460-466
• /
• 2019

It takes a lot of time and human resources to build a detailed three-dimensional finite element analysis model that is almost similar to the actual structure for sophisticated analysis, and a lot of experience and know-how is required to form a reliable analytical model. In this paper, the one-dimensional beam model connected by stiffness matrix through blade analysis library was compared with the results of three-dimensional analysis with the stress calculated through the process of dimensional restoration analysis based on the principle of virtual work. By comparing the stress calculated through dimensional restoration analysis with the three-dimensional analytical model, We will introduce the development status and application case of the blade analysis library by comparing efficiency and accuracy.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.10a
• /
• pp.341-347
• /
• 2000

Even for the same structure, the analysis results as well as design values might have differences depending on the selected analysis model. Therefore it is desirable to determin model considering the required accuracy of the analysis results, the given time restried economy. " Standard Specification for Roadway Bridges" Division V, Seismic Design prove "Single Mode Spectral Analysis Method" as the basic analysis method for the earthquake design of roadway bridges classified as "regular". In this study a 5 span steel box girl selected which satisfies the regularity and the applicability of the provided analysis simplified model in checked. For the comparision of the analysis results, "Multi-Mode Spect Method" is used with a detailed model.hod" is used with a detailed model.odel.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.10
• /
• pp.1838-1845
• /
• 2011

This paper deals with coupled electromagnetic-thermal field analysis for thermal fluid analysis of oil immersed power transformer. Electric power losses are calculated from electromagnetic field analysis and are used as input source of thermal field analysis based on computational fluid dynamics(CFD). Particularly, In order to accurately predict the temperature rise in oil immersed power transformer, the thermal problem should be coupled with the electromagnetic problem. Moreover, to reduce analysis region, the heat transfer coefficient is applied to boundary surface of the power transformer model. The coupling method results are compared with the experimental values for verifying the validity of the analysis. The predicted temperature rises show good agreements with the experimental values.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.19 no.4
• /
• pp.67-73
• /
• 2011

For loads analysis of airplane, applicable regulation should be determined. Then, loads conditions are prepared from the regulation. Modeling for aerodynamic, mass, and structure are performed. Panel method is usually adopted for aircraft loads analysis to obtain air loads. The ARGON which is a multidisciplinary fixed wing aircraft design software co-developed by the KARI and TsAGI are used for loads analysis. The ARGON can be utilized for flutter and stress analysis as well as for flight and ground loads analysis. In this paper, flight loads analysis for wing structural design of the regional aircraft at the conceptual design phase are performed with the ARGON. FAR 25 is used for the regulation for the load analysis. Shear force, bending moment and torsion diagrams for the wing and shear force and hinge moment for the aileron are presented.

• Proceeding of EDISON Challenge
• /
• 2015.03a
• /
• pp.274-278
• /
• 2015

There are different kinds of aircrafts, such as conventional airplane, rotorcraft, fighter, and unmanned aerial vehicle. Their shape and feature are dependent upon their assigned mission. One of the fundamental analyses during the design of the aircraft is the structural analysis. The structural analysis becomes more complicated and needs more computations because of the on-going complex aircrafts' structure. In order for efficiency in the structural analysis, a simplified approach, such as equivalent beam or plate model, is preferred. However, it is not clear which analysis will be appropriate to analyze the realistic configuration, i.e., an equivalent beam or plate analysis for an aircraft wing. It is necessary to assess the boundary between the one-dimensional beam analysis and the two-dimensional plate theory for an accurate structural analysis. Thus, in this paper, the static structural analysis results obtained by EDISON solvers were compared with the three-dimesional results obtained from MSC NASTRAN. Before that, EDISON program was verified by comparing the results with those from MSC NASTRAN program and analytic solution.

• Journal of the Korean Society of Safety
• /
• v.18 no.3
• /
• pp.141-148
• /
• 2003

Since the introduction of The Product Liability Law, effective since July 2002, more and more companies and end-users have been giving their attention to the safety of products. A number of existing risk analysis techniques are being implemented to manufacturing sites. However, they have certain restrictions such as incurring different techniques that are to be implemented at each stage of the product development. This is due to their domain of the analysis differing from one to another. Moreover, the results of these analyses are not specific enough, and are subject to further revision. This study proceeds to look at various examinations undertaken on the existing risk analysis techniques. Through implementing them on certain products, investigations on the strengths and weaknesses were ascertained. This has allowed improvements on the existing techniques to be achieved as tell as the development of a new risk analysis technique, 'HuBRA(Human Behavior Risk Analysis)'. Finally the new technique was implemented on products to confirm its effectiveness.

• Genomics & Informatics
• /
• v.18 no.1
• /
• pp.11.1-11.3
• /
• 2020

In genome-wide association studies, pathway-based analysis has been widely performed to enhance interpretation of single-nucleotide polymorphism association results. We proposed a novel method of hierarchical structural component model (HisCoM) for pathway analysis of common variants (HisCoM for pathway analysis of common variants [HisCoM-PCA]) which was used to identify pathways associated with traits. HisCoM-PCA is based on principal component analysis (PCA) for dimensional reduction of single nucleotide polymorphisms in each gene, and the HisCoM for pathway analysis. In this study, we developed a HisCoM-PCA software for the hierarchical pathway analysis of common variants. HisCoM-PCA software has several features. Various principle component scores selection criteria in PCA step can be specified by users who want to summarize common variants at each gene-level by different threshold values. In addition, multiple public pathway databases and customized pathway information can be used to perform pathway analysis. We expect that HisCoM-PCA software will be useful for users to perform powerful pathway analysis.