• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.457-463
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• 2013

Purpose: For effective quality assurance activities, BOM-based quality assurance method is presented. This study introduces various BOM conversions such as Q-BOM, T-BOM, and S-BOM based on M-BOM structure. Methods: Product quality control via Q-BOM manages inspection/audit information, overall supply-chain of product, part requirements, and inventory status. T-BOM manages part traceability, and S-BOM enables statistical control over key process and parts at various hierarchy levels. Results: Quality plan template was developed based on the study results of BOM system including Q-BOM, T-BOM, and S-BOM. Conclusion: Through BOM(Q-BOM, T-BOM, and S-BOM) study and development of quality plan template, more systematic and comprehensive quality management plan is achieved.

• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.251-261
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• 2010

This article demonstrated the application of the Fuzzy Data Envelopment Analytical Hierarchy Process (FDEAHP) to evaluate the root causes of critical defect problems occurring in the production of liquid medicine. The methodology of the research began by collecting the defect data by using Check Sheets, and ranking the significant problems by using a Pareto Diagram. Two types of major problems were found to occur, including glass fragments in the medicine and damaged lid threads. The causes of each problem were then analyzed by using Cause and Effect Diagrams. The significant causes were ranked by FDEAHP under three criteria, Severity (S), Occurrence (O) and Detection (D), followed by the framework of the FMEA Technique. Two causes with the highest Final Weight (FW) of each problem were selected to be improved, such as installing auxiliary equipment, using the Poka-Yoke system, setting the scale of the shaft and lathing the bushes of each bottle size. The results demonstrated a reduction in defects from 3.209% to 1.669% and showed that improving a few significant root causes, identified by an experienced decision maker, was sufficient to reduce the defect rate.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.456-460
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• 2006

많은 6시그마 혁신을 하는 기업 중에서 ISO9000 시리즈나 ISO/TS16949 인증을 받고 있다. 그럼에도 불구하고 6시그마 도입 초기부터 ISO/TS16949와 통합운영을 생각하고 추진하는 곳은 많지 않다. ISO/TS16949에서는 기업전반의 프로세스에 많은 중점을 두고 있다. 그 중에서도 APQP(Advanced Product Quality Planning)은 제품 초기에서부터 명확한 품질계획 업무 프로세스를 가지고 활동을 하라는 필수 프로세스를 요구하고 있다. 그러나 구체적인 Flow나 단계는 각 기업체의 특성에 맞기고 있다. 6시그마의 Lean DFSS는 이러한 제품개발 프로세스의 구체적인 전계단계를 제공하고 있다 여기에 APQP에서 요건으로 명시한 각 프로세스 단계마다 Input요소, Output요소, Target, 그 프로세스를 책임질 구성원, 핵심성공요인, 핵심성공지수, 단계마다의 FMEA(Failure Mode Effect Analysis) 분석을 대응하면 도입 초기에서부터 상호 유기적이면서 효과적인 System이 된다.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.9
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• pp.1001-1008
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• 2015

This paper introduces the architecture of the power supply in order to achieve the safety integrity target for power supply which is a part of safety related system. The integrity level for safety is set 4 and according to the IEC 62425 which is standard for railway application the architecture design is conducted and process for design is developed. The procedure for design consists with 6 steps. The architecture of power supply that is able to keep the safety integrity against of failure of power supply is derived through the analysis and it is suggested that the power supply adopted the result in this paper is suitable to apply in safety system. Also, the failure frequency that is a quantitative value for the power supply is proposed.

• Journal of Energy Engineering
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• v.24 no.1
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• pp.10-16
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• 2015

Recently, RCM(reliability centered maintenance) process is introduced and applied for the planning and implementing efficient and effective maintenance system in terms of optimal rolling stock maintenance. Particularly, cost-time benefits analysis associated with the implementation of RCM for rolling stock maintenance is necessary and required for railway operator in advance. The RCM process was primarily starting from military, airplane and nuclear industries and is now adapted in railway industry for local railway operators. This paper focuses on suggesting the way of connecting the RCM process with railway maintenance activities in the railway operation field. Thus, in order to introduce and establish reliability activities, it needs to review and evaluate the maintenance environment in the organizational point of view. Based on these reviews and evaluations, various maintenance methodologies are reviewed for customizing local railway field situations and establish specific process in the application of major systems on the reliability technology. In this paper, the railway RCM process is proposed for the establishment and construction of the systematic and optimal maintenance system.

• Journal of the Korean Society for Railway
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• v.14 no.5
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• pp.416-424
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• 2011

The recent development of USN (Ubiquitous Sensor Network) technology has broadened its applications to many fields of industry. The USN technology enables the system to monitor and control the status of distributed sensor nodes based on the low-powered communications. Applying the USN in the train control domain, the operational efficiency can be enhanced, where the reliability and the safety of the system are the key challenges. This paper suggests the system design for evaluating and improving the reliability and safety of the gateway, which is a USN component that manages the radio network among the sensors and collects the information from them. For this purpose, the reliability and the level of safety integrity of a general gateway have been predicted quantitatively and the supplementary design has been proposed for the selected week points. The verification on the reliability and the safety of the improved gateway according to the related standards has been followed. With the results of the study, the applicability of USN gateway for train control systems has been reviewed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.343-348
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• 2013

In line with the advances in factory automation, various pieces of equipment are now operated in batch processes controlled by computers. However, many kinds of faults can occur in complicated and large systems, which can result in low productivity and economic loss. The reliability and safety of systems have been studied because of the difficulty of determining the severity and location of faults. Therefore, it is necessary to detect and diagnose such faults in order to guarantee the reliability and safety of the equipment. In this paper, a diagnosis method for the ball bearings of a hydraulic pump is applied using a vibration signal for the maintenance of injection molding equipment. The bearings' defects are selected as a main failure mode through a failure mode and effect analysis (FMEA). Usually, there are nonlinear and impulse components of vibration in a ball bearing with faults. For the effective fault diagnosis of a ball bearing, nonlinear diagnostic methods and time-frequency analysis are applied, in addition to the methods currently used, such as power spectrum, time series analysis, and statistical methods. As a result of this study, a failure diagnosis system is provided that is useful even for non-experts. This is a condition-based method that makes it possible to resolve problems in a timely and economical way, in contrast to the prior method, which required regular but wasteful maintenance based on the experience of expensive external experts.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.3
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• pp.254-263
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• 2012

The survivability of warship is assessed by susceptibility, vulnerability and recoverability. Essentially, a vulnerability assessment is a measure of the effectiveness of a warship to resist hostile weapon effects. Considering the shot line and its penetration effect on the warship, present study introduces the procedural aspects of vulnerability assessments of warship. Present study also considers the prediction of penetration damage to a target caused by the impact of projectiles. It reflects the interaction between the weapon and the target from a perspective of vulnerable area method and COVART model. The shotline and tracing calculation have been directly integrated into the vulnerability assessment method based on the penetration equation empirically obtained. A simplified geometric description of the desired target and specification of a threat type is incorporated with the penetration effect. This study describes how to expand the vulnerable area assessment method to the penetration effect. Finally, an example shows that the proposed method can provide the vulnerability parameters of the warship or its component under threat being hit through tracing the shotline path thereby enabling the vulnerability calculation. In addition, the proposed procedure enabling the calculation of the component's multi-hit vulnerability introduces a propulsion system in dealing with redundant Non-overlapping components.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.31-38
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• 2019

The purpose of this study is to provide the priority of the front-loading factors in the design stage of the automotive parts development process in order to efficiently and effectively respond to the demands of the car maker (customer). Front-loading is defined as a strategy in order to improve development performance by shifting the identification and solving of design problems to earlier phases of a product development process. Two approaches of the front-loading are project-to-project knowledge transfer and rapid problem solving. For the study, a survey was conducted on the R&D department in the automobile parts company and analyzed by AHP (Analytic Hierarchy Process) method. The result of the survey shows the cost savings is the highest weight in terms of front-loading effect and in terms of front-loading factors, it gives priorities as "the problems of past project" first, "Design Review" second, "CAE (Computer Aided Engineering)" third, "FMEA (Failure Mode and Effects Analysis)" fourth, "benchmarking" and SR (Sourcing of Requirements). The results of the study will be helpful to provide practical value for improving product design of component development.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.230-231
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• 2019

This study is a development on condition based maintenance(CBM) technology which is a core item of future autonomous ships. It is developing to design & installation of condition monitoring system and acquisition & processing of data from ongoing ships for fault prediction & prognosis of engine in operation. The ultimate goal of this study is to develop a predicts and decision support software for marine engine faults. To do this, the FMEA and fault tree analysis of the main engine should be accompanied by the analysis of classification of system, identification of the components, the type of faults, and the cause and phenomenon of the failure. Finally, the CBM system solution software could predict and diagnose the failure of main engine through integrated analysis for bid-data of ongoing ships and engineering knowledge. Through this study, it is possible to pro-actively cope with abnormal signals of engine and to manage efficiently, and as a result, expected that marine accident and ship operation loss during navigation will be prevented in advance.