• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.7
• /
• pp.500-504
• /
• 2009

A reliability of software is a type of nonfunctional requirement. Traditionally, a validation of the reliability is processed at the integration phase in software development life cycle. However, it increases the cost and the risk for the development. In this paper, we propose reliability analysis method based on mathematical analytic model at the architecture design phase of the development process as follows. First, we propose the software modeling methodology for reliability analysis using Hierarchical combined Queueing Petri Nets(HQPN). Second, we derive the Markov Reward Model from the HQPN based model. We apply our approach to the video conference system to verify the usefulness of our approach. Our approach supports quantitative evaluation of the reliability.

• Proceedings of the Korean Reliability Society Conference
• /
• 2001.06a
• /
• pp.471-477
• /
• 2001

본 논문에서는 국가 경쟁력 제고를 위해 추진되고 있는 신뢰성 기술 기반 구축과 평가ㆍ인증제도에 대해 살펴보고 신뢰성 인증 제도의 필요성, 신뢰성 평가 네트워크, 국제적 신뢰성 인증제도의 구성 및 개발방향을 살펴보고 그 대응책을 모색해 본다.

• Journal of the Korean Society for Railway
• /
• v.11 no.3
• /
• pp.233-239
• /
• 2008

It is very important to set a reliability target and verify the requirement when procuring the rolling stock in the aspect of safety, availability and LCC. While there are a few different methods to verify the reliability target, it is required that the most appropriate method should be used considering the characteristics of rolling stock itself and the operation environment. Even though recently the quantitative reliability requirements are widely adopted in domestic market, there is no substantial contents in the various standards and guidelines. In this study we investigate the various reliability demonstration test plans and evaluate them for rolling stock application. And three test plans among them were applied to the real operation data.

• Journal of IKEEE
• /
• v.19 no.3
• /
• pp.431-439
• /
• 2015

This paper introduces analysis technique and test procedure for verifying the reliability of the multi-function radar software. Also the process of software development and reliability test method for reducing the development period are described. Test results show that the verified software has reduced errors and improved reliability compared to the unverified software.

• Journal of Applied Reliability
• /
• v.12 no.1
• /
• pp.47-56
• /
• 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.

• International Journal of Highway Engineering
• /
• v.5 no.1 s.15
• /
• pp.1-10
• /
• 2003

The objective of pavement design, just as with the design of other structures, is to obtain the most economical designs at specified levels of reliability. Methods that yield designs with different levels of reliability are undesirable, and over the course of time design approaches in the U.S. and Europe have converged toward the Load and Resistance Factor Design (LRFD) format in order to assure uniform reliability. At present the LRFD format has been implemented in concrete, steel, wood and bridge design specifications. In this paper, reliability theories are used to illustrate the development of an LRFD format for Mechanistic-Empirical (M-E) design of flexible pavements as an alternative of its reliability module. It is shown in this paper that ten candidate pavement sections designed with a reliability level using the AASHTO design guide (1986) do not have uniform structural reliability in terms of pavement mechanistic distress such as fatigue cracking and the uniform reliability can be achieved by using the LRFD format.

• Proceedings of the Korean Reliability Society Conference
• /
• 2005.06a
• /
• pp.157-163
• /
• 2005

신뢰성성장시험관리는 제품개발프로그램의 초기단계에서 고장모드를 확인하고, 이를 개선 또는 제거하기 위해 설계를 변경하고, 그 결과 진행되는 신뢰성이 향상되는 변화를 추적할 수 있는 실용적인 방법이다. 본 연구의 목적은 AMSAA(Army Materiel Systems Analysis Activity)모델을 이용하여 신뢰성 성장을 계획하고 평가할 수 있는 실용적인 방법을 제시하는데 있다. 시험-개선 과정을 통하여 성장하는 신뢰성 수준의 변화에 대한 추적과 예측 가이드라인을 제시함으로써 현장에서 활용할 수 있는 방법을 보여준다.

• Journal of Applied Reliability
• /
• v.13 no.4
• /
• pp.253-271
• /
• 2013

Since The Korean Reliability Society had been founded in 1999, development history of reliability engineering in Korea is reviewed and research outputs and papers from 2008 to current are analyzed in terms of types of industry, product life cycle, hardware vs software, and theory vs application. The purpose of this research is to review the recent reliability engineering research conducted in Korea including development history as well as published papers to identify the weakness and/or deficiencies in order to suggest the future research directions, which would contribute the development of industries in Korea.

• Journal of Applied Reliability
• /
• v.13 no.3
• /
• pp.165-174
• /
• 2013

Thruster break for aerogenerator performs a role that is stopping the rotor in case of emergency such as strong wind, system abnormality or maintenance check. In this study, failure analysis and test evaluation on the thruster break for aerogenerator are proposed, and the entire process to improve reliability of the product through design improvement is presented. The typical failure case is fatigue and wear, and failure cause on these are identified and improvement plan is presented. Lastly, reliability improvement is established to analyse test results before after the life test.

• Proceedings of the Safety Management and Science Conference
• /
• 2010.11a
• /
• pp.651-668
• /
• 2010

철도 시스템은 차량, 전력, 신호, 선로구축물시스템이 유기적으로 결합된 복합시스템으로 사고 발생 시 원인규명이 어렵고 인명에 치명적인 결과를 초래하게 되며 사소한 고장이라도 열차지연에 미치는 파급효과는 지대하여 시스템의 신뢰성확보가 매우 중요하다[26]. 실제로 세계 각국의 철도산업은 시스템의 신뢰성 향상을 위해 신뢰성 기법에 기반을 둔 다양한 이론을 통해 신뢰성 향상과 안전성 향상에 최선을 다하고 있다. 본 연구에서는 철도 신뢰성관리와 관련된 국내 연구동향과 철도 운영기관 및 기업에서 적용하고 있는 신뢰성 적용 현황을 분석한다. 그리고 국외 연구 동향과 주요 적용 현황을 정리한다. 또한 철도 신뢰성과 관련된 국내외 규격을 조사하고 이들 규격의 내용을 분석한 후 국내 적용방향을 제시한다.