• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.11
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• pp.625-631
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• 2003

The purpose of this paper is to assess experimentally system stability of the 154 ㎸ transmission system due to the current of the forthcoming AC High-Speed Railway (HSR) era. It introduces a simple method to evaluate the system stability The proposed method also shows the relationship between stability and power losses, and the stability indices made by the numerical process proposed in this paper will be used to assess whether a system can be stabilized or not. This paper also presents the improvement of the stability via loss reduction using STATCOM. Reactive power compensation is often the most effective way to improve both power transfer capability and system stability. The suitable modeling of the electric railway system should be applicable to the PSS/E. In the case study the proposed method is tested on a practical system of the Korea Electric Power Corporation (KEPCO) which will be expected to accommodate the heavy HSR load. Furthermore, it prove that the compensation of voltage drop and its by-product, loss reduction is closely related to improvement of system stability.

• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.37-46
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• 1997

KOSIS(Korean Statistical Information System) was developed and serviced by National Statistical Office in Korea. In this paper, we report the survey results of the usage of KOSIS, and its improvement. Finally, we propose some recommendations for improvement of KOSIS, and discuss the usage of KOSIS in behalf of end-users.

• Proceedings of the Safety Management and Science Conference
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• 2000.11a
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• pp.243-249
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• 2000

An improvement activity is necessary for the existence strategy of the corporate. We search effective activities by the integration, implemention of the Quality Control Circlle and the Suggestion Activity System on the various improvement activity. Therefore, Each of the concept and step are surveyed. We output the commonness and the difference, and propose "The Suggestion Circle Activity" that is the new integration, improvement activity. activity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.30
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• pp.81-87
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• 1994

Productivity relates output to input and also integrates performance aspects of quality, efficiency and effectiveness. Productivity improvement are associated with efficiency and effectiveness, productivity index involved quality and flexibility, integrated productivity measurement system, and other factors. This study focused on the productivity improvement that involved the opportunity costs such as qualify costs and flexibility effects.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.435-449
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• 1998

Continuous quality improvement (CQI) has been promoting progresses of the social, and which is being studied and applied in much more widespread area at present. This paper systematically studies and reports research results of continuous quality improvement, involved in several key viewpoints of CQI such as the background of management and engineering philosophy on CQI, the objectives of CQI, the ways to implement CQI, the objects of CQI based on process. In terms of management methodology, the results of discussion on Benchmarking & CQI, standardization management and its certification & CQI, TQM pyramid & CQI and self-assessment & CQI etc. are reported. In quality engineering field, CQI culture of variation reduction is presented. Actually this paper is a comprehensive research project report of 'Continuous Quality Improvement System', supported jointly by NSFC and KOSEF.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.3
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• pp.211-220
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• 2002

CGS(Compaction Grouting System) is widely used in reinforcement of structural foundation and ground improvement in soft ground. But the effects of ground improvement depending on the type of soil must be studied in order to adopt in various soils (granular soil and cohesive soil). In this study, characteristics of ground improvement (the increase of N value, increase in unit weight, vertical displacement on the ground surface) by CGS method was compared through two cases that were performed in granular and cohesive soil. The results show that the closer to the grout hole, the more increase in N value and this trend appear distinctly in granular soil. Unit weight of ground increase largely near by the grout hole and decrease in far from it independently of the soil type. The vertical displacement on the ground surface appeared in smaller area in case of granular soil than cohesive soil.

• Journal of the Korea Safety Management & Science
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• v.12 no.3
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• pp.215-221
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• 2010

Many researches and projects are actively implemented in the academic world and industrial world in order to increase the productivity through changing utility layout. Effective layout makes the flow of parts and products go on wheels and helps labor forces and utilities to be used efficiently. In this study, we looked at effect on utility layout change through a case of a company making a fuel tank of vehicle in Korea. Due to the layout improvement, this company could have flowshop system on welding line, so the stock in line was decreased, checking the number of stock became easier than before and it was possible to evaluate exact cycle time per unit. Through not only confirming qualitative effect, but also checking quantitative effect such as UPH(Unit per Hour), we obtained the conclusion that the layout improvement increased the productivity.

• Korea Trade Review
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• v.44 no.2
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• pp.143-157
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• 2019

The purpose of this study is to review domestic and foreign origin labeling system in order to implement origin labeling system in the perspective of protecting the interests of consumers, and to suggest governmental improvements by analyzing problems embedded in current labeling system. The results analysis show complexity of related legal system, lack of expertise at the stage of labeling, and inefficiency of crackdown authority. The improvement could be suggested in two ways: supporting plans for the ones who have duty of labeling and improvement plans in origin management system. As supporting plans, we suggest the need for an automatic origin determination system, appropriate education on origin stakeholders, and introduction of origin certification system. For improvement plans, there are unification of country of origin labeling related laws, utilization of FTA product specific rules, and QR code, expert confirmation system. Since the origin labeling issue has become important, proactive and quick responses must follow with thorough examination the effect of the origin labeling on consumer welfare.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1155-1160
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• 2017

This paper describes a system implementation for the automatic inspection on the ventilating electronic device based on the reliability improvement. To be enhancement, the inspection error is minimized by the automatic inspection system on the ventilating apparatuses against the manual inspecting system. The system consists of the control system, software structure and monitoring system to be scanning the inspection processing. The inspection system for reliability improvement is evaluated in Gage Repeatability and Reproducibility. The experimental results are improved about 2 times inspecting speed, measured error ${\pm}0.02V$, effectiveness of discriminating performance 15%, missing probability 17% and false alarm probability 12% respectively in comparing with the manual inspection based on the wind pressure sensor. The system will be also improved more by making database and product bar codes for the total quality control system to the effective reliability enhancement in the future.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.49-59
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• 2016

Naval combat system developed in-country is progressing at an alarming rate since 2000. ROK navy will be achieved all vessels that have combat system in the near future. The importance of System Engineering and Integrated Logistics Support based on reliability analysis is increasing. However, reliability analysis that everyone trusted and recognized is not enough and applied practically for development of Defense Acquisition Program. In particular, Existing Reliability Analysis is focusing on reliability index (Mean Time Between Failure (MTBF) etc.) for policy decision of defense improvement project. Most of the weapon system acquisition process applying in the exponential distribution simply persist unreality due to memoryless property. Critical failures are more important than simple faults to ship's operator. There are no confirmed cases of reliability analysis involved with critical failure that naval ship scheduler and operator concerned sensitively. Therefore, this study is focusing on Mean Time To Critical Failure (MTTCF), reliability on specific time and Operational Readiness Float (ORF) requirements related to critical failure of Patrol Killer Guided missile (PKG) combat system that is beginning of naval combat system developed in-country. Methods of analysis is applied parametric and non-parametric statistical techniques. It is compared to the estimates and proposed applications. The result of study shows that parametric and non-parametric estimators should be applied differently depending on purpose of utilization based on test of normality. For the first time, this study is offering Reliability of ROK Naval combat system to stakeholders involved with defense improvement project. Decision makers of defense improvement project have to active support and effort in this area for improvement of System Engineering.