• 한국신뢰성학회지:신뢰성응용연구
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• 제14권1호
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• pp.53-57
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• 2014

In the fields of reliability application, the most commonly used test methods for reliability demonstration are zero-failure acceptance tests since they require fewer test samples and less test time compared to other test methods that guarantee the same reliability with a given confidence level. For products with lognormal lifetime distribution, the value of scale parameter is usually assumed to be known in designing reliability demonstration tests. It is important to select correct values of scale parameters to guarantee the specified reliability with given confidence level exactly. The effect of using wrong values of scale parameters in designing reliability demonstration test for products with lognormal lifetime distribution is examined and selecting proper values of scale parameters for conservative reliability demonstration is discussed.

• 한국신뢰성학회지:신뢰성응용연구
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• 제13권1호
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• pp.1-10
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• 2013

A Bayesian zero-failure reliability demonstration test method for products with exponential lifetime distribution is presented. Beta prior distribution for reliability of a product is used to design the Bayesian test plan and selecting a prior distribution using a prior test information is discussed. A test procedure with zero-failure acceptance criterion is developed that guarantees specified reliability of a product with given confidence level. An example is provided to illustrate the use of the developed Bayesian reliability demonstration test method.

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권4호
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• pp.220-224
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• 2014

A Bayesian zero-failure reliability demonstration test method for products with Weibull lifetime distribution is presented. Inverted gamma prior distribution for the scale parameter of the Weibull distribution is used to design the Bayesian test plan and selecting a prior distribution using a prior test information is discussed. A test procedure with zero-failure acceptance criterion is developed that guarantee specified reliability of a product with given confidence level. An example is provided to illustrate the use of the developed Bayesian reliability demonstration test method.

• 한국신뢰성학회지:신뢰성응용연구
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• 제13권4호
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• pp.299-307
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• 2013

The value of blood sugar is measured by a personal blood glucose meter which consists of two parts: a glucose strip and a blood glucose meter. A personal blood glucose meter makes use of electric media which are composed of glucose oxidase and electron. This study is to propose a method of reliability demonstration test derived from field data analysis and FMEA(Failure Mode and Effect Analysis). Detailed Conditions for reliability demonstration test are selected from the comparison of various failure mechanisms. The most dominant failure mechanism is wear-out which is caused by strip insertion/extraction. The testing device that can reproduce the failure mechanism of strip insertion/extraction is made to conduct reliability demonstration test. Using the testing device, it is confirmed that target lifetime of selected devices is more than 2 years.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권1호
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• pp.47-56
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• 2012

Reliability demonstration tests with zero-failure acceptance criterion are most commonly used in the field of reliability application since they require fewer test samples and less test time compared to other test methods that guarantee the same reliability with a given confidence level. For products with lognormal lifetime distribution, an economic zero-failure test plan is developed that minimizes the total cost related to perform a life test to guarantee a specified reliability of a product with a given confidence level. A numerical example is provided to illustrate the use of the proposed test plan.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권3호
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• pp.170-175
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• 2015

Reliability demonstration tests (RDT's) are widely employed in design verification and process validation stages of industry. New mixed attribute-variable RDT plans that compromise demerits of the corresponding zero and zero or one failure plans which are common in practice are developed for the exponential distribution. The proposed mixed plans are compared with the typical RDT plans in terms of probability of acceptance and expected test termination time. A numerical example is provided to illustrate the mixed plans and a procedure to extend these plans to the Weibull distribution with known shape parameter is also presented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.577-581
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• 2009

The fixed duration test has been widely used in the reliability demonstration test for rolling stocks. This article deals with how to design the test statistics, acceptance criteria and the fixed duration of the MTBF(Mean Time Between Failures) demonstration test considering the consumer risk. Numerical examples are given to illustrate the dependence of the consumer risk on the test duration and MTBF requirement.

• 대한산업공학회지
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• 제43권2호
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• pp.147-153
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• 2017

In order to demonstrate a target reliability with a specified confidence level, a new two-stage Bayesian Reliability Demonstration Test (RDT) plans that is known to be more effective than a corresponding single-stage one is proposed and developed by Bayesian framework with beta prior distribution for Weibull life time distribution. A numerical example is provided to illustrate the proposed RDT plans and compared with other non-Bayesian and Bayesian plans. Comparative results show that the proposed Bayesian two-stage plans have some merits in terms of required and expected testing time and probability of acceptance.

• 품질경영학회지
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• 제39권2호
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• pp.313-319
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• 2011

In design verification and process validation stages, reliability demonstration tests(RDT's) are common practice in industry, A new two-stage RDT that is known to be more efficient than a corresponding single-stage one in terms of expected test duration for Weibull distribution is proposed. Zero or one failure two-stage plans to minimize expected test duration under Type I and hybrid censoring subject to satisfying consumer's risk at a specified reliability target are developed and a numerical example is provided to illustrate the proposed two-stage RDT plans and compared with other one- and two-stage plans.

• 한국철도학회논문집
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• 제11권3호
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• pp.233-239
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• 2008

철도차량을 구매하는 데 있어서 신뢰성 목표값을 설정하고 차량 납품 시 이 목표값을 달성하였는지 확인하는 것은 전체 차량의 안전성과 가용성 그리고 전수명주기 측면에서 매우 중요하다. 신뢰성을 검증하는 방법은 여러 가지가 있으나 철도차량 자체의 특성과 운영환경 등을 고려하여 가장 적합한 시험방법을 적용할 필요가 있다. 최근 들어 국내에서도 차량 구입시 정량적 신뢰성 요구사항이 일반화되고 있으나 철도차량에 대한 각종 표준이나 지침에서는 정량적 신뢰성 입증에 대한 구체적 방법에 대한 내용은 없다. 본 연구에서는 다른 산업분야에서 활용되는 신뢰성 검증방법에 대해서 기술하고, 이 방법들을 철도차량에 적용할 수 있는 지 평가하였다. 그리고 이중 세 가지 방법을 철도차량의 실제 운영데이터에 적용해 보았다.