• 한국신뢰성학회지:신뢰성응용연구
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• 제16권4호
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• pp.263-271
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• 2016

Purpose: A slurry pump for flue gas desulfurization system performs a role that discharges the slurry of a plaster shape in a thermal power plant. Since a slurry pump transfers the slurry by the centrifugal force, it has the friction wear in the impeller and liner because of the slurry. Methods: In this study, failure analysis and test evaluation on the slurry pump have been proposed and the process that reliability of the product improves through design improvement has been presented. And failure cause of typical failure case has been investigated and improvement design has been presented. Results: Reliability improvement is established by analysis of the test results of before and after acceleration test. Conclusion: This study can be provided to improve the product reliability through failure analysis of a slurry pump.

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권4호
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• pp.236-242
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• 2014

Since permanent magnet coupling transfers power by magnetic force without contact, it has little shock, vibration, noise. In case of overload, it protects a pump or a motor which is relatively important by slipping internally. In this study, failure analysis and test evaluation on the permanent magnet coupling have been proposed and the process that reliability of the product improves through design improvement has been presented. And failure cause of typical failure case has been investigated and improvement plan has been presented. Finally, reliability improvement is established by analysis of the test results of before and after acceleration test.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 추계학술대회
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• pp.269-276
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• 2004

Special, high technology developments and systems improvements become more necessary as the industrial society is becoming complex. When some systems are developed, it is common that developed systems have low-reliability in infant period. Some developed systems need tests to improve their reliability up to the respected level before adapting them. This paper aims at showing the testing program including the reliability growth model for reliability improvement of the Light Rail Transit

• 품질경영학회지
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• 제43권4호
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• pp.499-510
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• 2015

Purpose: This paper treats the improvement of the quality and reliability of military weapon systems based on the maintenance data. Methods: The proposed method of the data integration and refinement are used to obtain the component reliability information and to find the frequently failed components based on the Pareto analysis. Based on the reliability information and the number of failed component frequencies, the target components of quality improvement are determined and improved by multiple methods such as engineering changes, special meetings, additional training and revising maintenance manuals. Results: Based on the proposed process, we find some components which need to be improved in order to enhance the quality and reliability. Conclusion: A process is developed for improving the quality and reliability of weapon systems. This process will be adopted by various weapon systems to enhance the quality and reliability, as well as reduce military spending.

• 한국안전학회지
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• 제25권2호
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• pp.24-28
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• 2010

The nuclear power Plant onsite AC electrical power sources are required to supply power to the engineering safety facility buses if the offsite power source is lost. Typically, Diesel Generators are used as the onsite power source. The 125 VAC buses are part of the onsite Class 1E AC and DC electrical power distribution system. The DC power distribution system ensure the availability of DC electrical power for system required to shutdown the reactor and maintain it in a safety condition after an anticipated operational occurrence or a postulated Design Base Accident. Recently, onsite DC power supply system trip occurs the loss of system function. To obtain the performance such as reliability and availability, we analyzed the cause of battery charger trip and described the improvement of DC power supply system reliability. Finally, we provide reliability performance criteria of charger in order to ensure the probabilistic goals for the safety of the nuclear power plants.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.502-507
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• 1997

As a maintenance optimization project to improve the safety of Wolsong NPP (Nuclear Power Plant), reliability of diesel generators are estimated based on the operating experience, and improvement options are suggested. A reliability measure is suggested for the estimation of reliability for standby safety systems to reflect availability. It is assessed that the reliability of diesel generators can be much improved if the suggested improvement options are implemented.

• 한국유기농업학회지
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• 제20권2호
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• pp.125-142
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• 2012

The purposes of this study are to analyze the effect of consumption of environment-friendly agricultural products (EFAP) on improvement of family health, and to suggest directions for improvement of family health. A survey was conducted for qualitative analysis regarding relationship between EFAP consumption and family health. The method of his study was employed Cross-tabulation and an Ordinal Logistic Regression Model to derive more significant results in analyzing factors of improvement of family health. The result shows that improvement of health has a significant positive relationship with consumption of EFAP. In addition, those consumers with high reliability and quality contentment are more likely to experience improvement of health. As consumers constantly eat EFAP, they are more likely to experience improvement of health. In order to provide consumer reliability of EFAP, more strict certification management system with sound monitoring and an appropriate penalty for violation should be established.

• 항공우주기술
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• 제2권1호
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• pp.205-212
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• 2003

신뢰성이란 부품이나 시스템이 얼마나 오랫동안 안심하고 사용할 수 있는가를 정량적 수치로 표현하는 미래의 품질 개념으로 앞으로 제품의 국제적인 경쟁력을 갖추기 위하여 필수적으로 요구되는 기술이다. 국내에서도 제품의 신뢰성 향상에 대한 관심과 필요성이 더욱 고조됨에 따라, 정부에서도 세계적 수준의 신뢰성 평가 인프라를 구축하기 위해 “신뢰성 향상 기반 구축사업”을 적극적으로 추진하고 있으며, 대학, 연구기관 및 전자, 자동차, 중공업 등 수출업체에서 신뢰성에 관한 연구 및 시험평가센터를 설립하여 본격적으로 신뢰성 문제를 다루고 있다. 본 논문에서는 신뢰성 향상 사업에 대한 국내의 현황을 소개하고 항공우주분야에 대한 신뢰성 인증제도 도입의 필요성에 대하여 검토하였다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권4호
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• pp.280-288
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• 2017

Purpose: PBA buried in underwater requires high reliability because of its mission critical characteristic and harsh operational environment during its life cycle. Therefore, various reliability improvement activities are necessary. The defect on PBA manufacturing process have been studied, as a result, many activities and standards have been presented. However, there are less studies regarding failure pattern on physical features based on design. In this paper, we studied a possible failure patten based on physical features that is related with manufacturing process of PBA. And reliability improvement design based on PoF (Physical of Failure) were intruduced in this paper. Methods: A reliability prediction simulation were performed on the components A and B of the H system using Sherlock Software which is a PoF commercial tool from DFR solution. Solder fatigue and PTH fatigue analysis based on thermal cycling profiles and random vibration was analyzed on three earthquake response spectrum. Result: It was validated that life time and reliability improvement design through solder fatigue and PTH fatigue analysis in case of component. For compoenet B, random vibration fatigue was additionally analyzed and validated reliability for earthquakes profile. Conclusion: In design stage prior to manufacturing, PoF can be analyzed, and it is possible to make a reliability improvement/validated design using design data. This study can be applied in every design step and contribute to make more stable development product.

• 산업경영시스템학회지
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• 제39권4호
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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.