• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2006년도 춘계학술대회
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• pp.69-75
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• 2006

As the level of technology and the standard of living improve, product reliability plays an Increasingly significant role. This study has been performed to build a reliability model of electronic ballasts for the low wattage fluorescent lamp. Telcordia SR-332, one of the most widely used reliability specifications, was selected for the model development. We briefly reviewed the basic concepts of the electronic ballast. We then developed a reliability model for the ballast using SR-332 concepts and the reliability has been examined.

• 한국신뢰성학회지:신뢰성응용연구
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• 제9권1호
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• pp.1-12
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• 2009

BLDC motors are stored in the devices such as CD-RW, COMBO, DVD-ROM and CD-ROM. It is indispensable to establish reliability assessment criteria for BLDC motors, especially in the world where IT grows rapidly. In this article, reliability certification procedure is given. The reliability certification procedure consists of two separate tests such as quality certification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 춘계학술대회
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• pp.663-674
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• 2011

Continuing and Developing the growth, the company should focus on 'time to market of high quality production' and 'cost down'. Due to the complexity of the production, reliability is being one of the important factor. In this study, in particular, focus on parts reliability test improvement about printer product and proceeded. Need test improvement for time to market that is developed, and reduce expense with test period that is required at Reliability Test time of new parts and should high quality level of product. Finally huge Failure Cost (F-COST) occurs because quality level of product drops if parts that accomplish product does not ensure reliability and this is associated by malfunction in marketplace.

• 대한안전경영과학회지
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• 제12권3호
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• pp.153-162
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• 2010

Continuing and Developing the growth, the company should focus on 'time to market of high quality production' and 'cost down'. Due to the complexity of the production, reliability is being one of the important factor. In this study, in particular, focus on parts reliability test improvement about printer product and proceeded. Need test improvement for time to market that is developed, and reduce expense with test period that is required at Reliability Test time of new parts and should high quality level of product. Finally huge Failure Cost (F-COST) occurs because quality level of product drops if parts that accomplish product does not ensure reliability and this is associated by malfunction in marketplace.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권2호
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• pp.83-91
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• 2017

Purpose: The purpose of this study is to develop a quality assurance model and to determine appropriate warranty period for a guided missile using its field data. Methods: 10 years of actual firing data is collected from the defense industry company and military. Parametric maximum likelihood estimation for a reliability function is determined with the data. Results: The reliability function estimates average lifetime of the missile. That function shows a user requirement, 80% reliability (lifetime) is come up when 8 years have passed, which is longer than the estimates in the missile's development phase. Conclusion: Quality assurance warranty for a guided missile must be established with actual test data. It is necessary to update and modify the reliability prediction and the warranty period with actual field test data.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권1호
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• pp.1-12
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• 2012

The quality of a part has directly effect on part reliability. In the basis of MIL-HDBK-217F model, it is the determined rule that part's quality level should follow its nominal one written in its specification. If quality information is unknown, quality level of the part should be determined as 'Lower'. However, the prediction model is said to be short in reflecting parts applying 'state-of-the-art' technology and result in over-estimated failure rate by some reliability-related authorities or research institutes. In this study, the reliability prediction results by the model of MIL-HDBK-217F and Telcordia SR-332 are compared and analyzed to verify whether the statement is reasonable or not.

• 대한전기학회논문지:전력기술부문A
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• 제52권12호
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• pp.705-712
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• 2003

In this paper, we propose new unified methodologies of reliability and its cost evaluation in power distribution systems. The unified method means that the proposed reliability approaches consider both conventional evaluation factor, i.e. sustained interruptions and additional ones, i.e. momentary interruptions and voltage sags. Because the three voltage quality phenomena generally originate from the outages on distribution systems, the basic and additional reliability indices are summarized considering the fault clearing mechanism. The proposed unified method is divided into the reliability evaluation for calculating the reliability indices and reliability cost evaluation for assessing the damage of customer. The analytic and probabilistic methodologies are presented for each unified reliability and its cost evaluation. The time sequential Monte Carlo technique is used for the probabilistic method. The proposed DVL(Demand Varying Load) model is added to the reliability cost evaluation substituting the average load model. The proposed methods are tested using the modified RBTS(Roy Billinton Test System) form and historical reliability data of KEPCO(Korea Electric Power Corporation) system. The daily load profile of the each customer type in domestic are gathered for the DVL model. Through the case studies, it is verified that the proposed methods can be effectively applied to the distribution systems for more detail reliability assessment than conventional approaches.

• 품질경영학회지
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• 제44권1호
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• pp.109-120
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• 2016

Purpose: This study developed a method of determining priorities for evaluating and revising defense standards. Methods: The proposed data integration and refinement methods are used to obtain component reliability information and to determine the frequency of component citation based on Pareto analysis. Based on the reliability information and the frequency of cited components, the target components for quality improvement can be determined and improved using various methods, such as engineering changes, special meetings, additional training, and revising the maintenance manual. Results: Based on the proposed process, we identified components that need to be improved in order to enhance the quality and reliability. Conclusion: Our process will improve the quality and reliability of weapon systems. The proposed process can be adopted for various weapon systems to enhance their quality and reliability, and to reduce military spending.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2007년도 춘계학술대회
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• pp.331-333
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• 2007

Product reliability is important to quality and competitiveness. Much management and engineering efforts go into evaluating reliability, assessing new designs and changes of manufacturing processes, identifying cause of failure. Major methods are based on environmental test. In this study, we analysis the environmental test data of the electrical component, unit, set. These data were gathered for 7 years.

• 품질경영학회지
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• 제35권2호
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• pp.27-36
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• 2007

A study to build a reliability model of electronic ballasts for the fluorescent lamp has been performed in this study. We selected the widely being used specification, MIL-HDBK-217 for the study. We briefly reviewed the basic concepts of the electronic ballast with the selected reliability specification. We then developed a reliability model for the ballast using MIL-HDBK-217 and predicted the reliability. We further provided some guides which should be considered in future model development.