• 응용통계연구
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• 제23권3호
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• pp.573-584
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• 2010

This paper considers the differences in the software execution environments in the testing phase and the operational phase to determine the optimal release time and warranty period of software systems. We formulate equations for the total expected software cost until the end of the software life cycle based on the NHPP. In addition, we derive the optimal release time that minimizes the total expected software cost for an imperfect debugging software reliability model. Finally, we analyze the sensitivity of the optimal testing and maintenance design related to variation of the cost model parameters based on the fault data observed in the actual testing process, and discuss the quantitative properties of the proposed model.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 춘계학술대회
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• pp.153-165
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• 2009

It is hot issue to get the competitiveness of product through reliability-growth as well as availability and safety in almost high-technology industry including military, chemistry, nuclear, telecommunication, transportation service and so on. In advanced countries, they experienced remarkable growth based on reliability technology in materials&parts industry as well as high-tech industry. It has become a symbol of national competitiveness and created a higher value added. This paper is taking on effectively developing ways to deploy IEC 60300 dependability management system and the base technology that are needed to improve competitiveness of industries in Korea.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1014-1023
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• 2008

The K-AGT test line is managed similarly to revenue operation and operated automatically 120km per day, total 90,000km from August 2004 to December 2007. To enhance reliability of developed system, maintenance information system based on RCM is applied. The maintenance program applied in test line is based on RCM which prevent a fault before it happens and a fault made in test line is analysed by reliability growth test. Vehicle system, power supply system, signalling system, track and infrastructure are built in test line and it is reviewed enhancing system performance and changing designs to commercialize through reliability growth analysis method.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권1호
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• pp.15-25
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• 2016

Purpose: The purpose of this study is to identify the success factor of local food markets compared to other types of markets such as large discount stores. Methods: SWOT analysis was conducted. In addition to the analysis, we also have interviewed the local farmers and retailers to elaborate the analysis results. Results: The study shows the success factors to the local markets are minimizing the stages of distribution channels, shortening the travel distance from producers to consumers, providing fresh foods, maintaining small amount of production system, and supporting customers. Conclusion: Customer satisfaction is one of the key factors for the successful growth of local food markets. It is strongly recommend to find strategic ways of meeting customer needs since the local food markets are facing tough competition form the large retail stores armed with huge amount of capitals and infrastructures.

• 정보처리학회논문지D
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• 제9D권4호
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• pp.659-666
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• 2002

Park, Seo and Kim은 소프트웨어의 시험단계와 유지보수단계에 모두 적용할 수 있는 입력 영역 기반 소프트웨어 신뢰성 성장 모델을 개발하였다. 이들의 모형은 완전디버깅의 가정 하에서 개발되어졌다. 입력 영역 기반 소프트웨어 신뢰성 성장 모델이 현실적이기 위해서는 이러한 가정은 개선되어야 한다. 본 논문에서는 불완전 디버깅 하에서 사용할 수 있는 입력 영역 기반 소프트웨어 신뢰성 성장 모델을 제안하고 그 통계적 특성을 조사한다.

• 한국정보처리학회논문지
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• 제7권3호
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• pp.852-861
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• 2000

Software reliability growth models are used in testing stages of software development to model the error content and time intervals betwewn software failures. In this paper, using priors for the number of fault with the negative binomial distribution nd the error rate with gamma distribution, Bayesian inference and model selection method for Jelinski-Moranda and Goel-Okumoto and Schick-Wolverton models in software reliability. For model selection, we explored the sum of the relative error, Braun statistic and median variation. In Bayesian computation process, we could avoid the multiple integration by the use of Gibbs sampling, which is a kind of Markov Chain Monte Carolo method to compute the posterior distribution. Using simulated data, Bayesian inference and model selection is studied.

• 품질경영학회지
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• 제39권2호
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• pp.170-178
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• 2011

In general, a software fault detection phenonenon is described by a software reliability model based on a nonhomogeneous Poisson process(NHPP). In this paper, we propose a software reliability growth model considering the differences of the software environments in both the testing phase and the operational phase. Also, we consider the problem of determining the optimal release time and the optimal warranty period that minimize the total expected software cost which takes account of periodic software maintenance(e.g. patch, update, etc). Finally, we analyze the sensitivity of the optimal release time and warranty period based on the fault data observed in the actual testing process.

• 한국철도학회논문집
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• 제8권5호
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• pp.434-438
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• 2005

In this paper, as the first step to assess and enhance the reliability of Korea High Speed Train, an electric traction system is selected and reliability analysis is carried out. The electric traction system is classified into subsystems and functional block diagrams and reliability block diagrams are drawn. Expressions for evaluating the reliability are derived and Mean Kilometer Between Service Failure is calculated using the trial track test results. The calculation results show reliability growth of the proposed system.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.350-353
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• 2009

가스터빈엔진에서 고열부의 수명은 안전성 평가와 신뢰성 분석을 위하여 설계 시부터 면밀히 평가 되어야한다. 수명평가 과정에서는 구조 형상의 불확실성, 작용하중의 변동성, 재료물성의 분포 등으로 인해 계산된 수명 또한 불확실하게 되며, 불확실 인자들에 대한 수명의 강건성을 확보하기 위하여 신뢰성 평가가 요구된다. 본 논문에서는 고온, 고회전하는 가스터빈엔진 터빈의 피로균열 성장수명을 선형탄성파괴역학(LEFM)을 적용하여 계산하였으며, 1차 신뢰도법(FORM)과 몬테카를로 시뮬레이션기법을 사용하여 계산된 수명의 신뢰도를 평가하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2008년도 추계학술발표대회 및 제15회 신소재 심포지엄
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• pp.28.1-28.1
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• 2008