• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2006년도 춘계 종합학술대회 논문집
• /
• pp.444-447
• /
• 2006

본 논문에서는 소프트웨어 테스트 단계중에 발생되는 테스트노력 소요량을 고려한 소프트웨어 신뢰도 성장 모델을 제시하여 시간종속적인 테스트 노력소요량 동태를 일정 테스트 노력일 때와 웨이블 테스트 노력일 때를 비교하여 연구한다. 소프트웨어 신뢰도 척도에 대한 데이터 분석기법을 개발하도록 한다. 테스트 시간의 경과와 신뢰도와의 관계도 심도 있게 연구한다. 목표신뢰도를 만족시키는 최적발행시각을 정한다. 개발 후 테스트를 시작하기 전의 신뢰도가 어떠한 조건에 있는가를 검토하여 각 조건에 따른 최적 발행시각을 결정한다.

• 한국신뢰성학회:학술대회논문집
• /
• 한국신뢰성학회 2000년도 춘계학술대회 발표논문집
• /
• pp.177-183
• /
• 2000

As monitoring, testing, and measuring techniques develop, predictive control of components and complete systems have become more practical and affordable. In this paper we develop a statistics-based approach assuming nonlinear degradation paths and time-dependent standard deviation. This approach can be extended to provide reliability estimates and limit value determination in the censoring case fur predictive maintenance policy.

• International Journal of Reliability and Applications
• /
• 제6권2호
• /
• pp.117-133
• /
• 2005

Estimations of the parameters included in a two-component system are derived based on masked system life test data, when the probability of masking depends upon the exact cause of system failure. Also estimations of reliability for the individual components at a specified mission time are derived. Maximum likelihood and Bayes methods are used to derive these estimators. The problem is explained on a series system consisting of two independent components each of which has a Pareto distributed lifetime. Further we present numerical studies using simulation.

• Advances in aircraft and spacecraft science
• /
• 제9권3호
• /
• pp.263-278
• /
• 2022

The time-varying structural reliability of an aeroelastic launch vehicle subjected to stochastic parameters is investigated. The launch vehicle structure is under the combined action of several stochastic loads that include aerodynamics, thrust as well as internal combustion pressure. The launch vehicle's main body structural flexibility is modeled via the normal mode shapes of a free-free Euler beam, where the aerodynamic loadings on the vehicle are due to force on each incremental section of the vehicle. The rigid and elastic coupled nonlinear equations of motion are derived following the Lagrangian approach that results in a complete aeroelastic simulation for the prediction of the instantaneous launch vehicle rigid-body motion as well as the body elastic deformations. Reliability analysis has been performed based on two distinct limit state functions, defined as the maximum launch vehicle tip elastic deformation and also the maximum allowable stress occurring along the launch vehicle total length. In this fashion, the time-dependent reliability problem can be converted into an equivalent time-invariant reliability problem. Subsequently, the first-order reliability method, as well as the Monte Carlo simulation schemes, are employed to determine and verify the aeroelastic launch vehicle dynamic failure probability for a given flight time.

• 품질경영학회지
• /
• 제24권3호
• /
• pp.19-30
• /
• 1996

We treat problems of estimating reliability R(t) = P[Y(t) ＞ X(t)] in the time dependent strength-stress model in which a unit of stress X(t) is subjected to environmental strength Y(t) at time t. In this paper we introduce a special model of R(t) with fixed strength and unaccumulated stress case, and propose a Mann-Whitney-Wilcoxon type estimator of R(t).

• 한국신뢰성학회:학술대회논문집
• /
• 한국신뢰성학회 2001년도 정기학술대회
• /
• pp.273-275
• /
• 2001

With the continuous advancement in electronics technology, especially the usage of new materials and the introduction of new and immature manufacturing process, stress and time dependent types of physical, chemical and mechanical imperfections are introduced to the electronic hardware. These types of imperfections are called flaws. A reliability stress screening process(RSS) is a process which involves the application of operational and/or environmental stress to electronic hardware on a 100% basis, for the purpose of precipitating inherent, as well as process-induced, flaws while neither destroying nor degrading in a significant way the hardware being stressed.

• Journal of Information Technology Applications and Management
• /
• 제12권2호
• /
• pp.1-13
• /
• 2005

This paper proposes a software-reliability growth model incoporating the amount of testing effort expended during the software testing phase after developing it. The time-dependent behavior of testing effort expenditures is described by a Logistic curve. Assuming that the error detection rate to the amount of testing effort spent during the testing phase is proportional to the current error content, a software-reliability growth model is formulated by a nonhomogeneous Poisson process. Using this model the method of data analysis for software reliability measurement is developed. After defining a software reliability, This paper discusses the relations between testing time and reliability and between duration following failure fixing and reliability are studied. SRGM in several literatures has used the exponential curve, Railleigh curve or Weibull curve as an amount of testing effort during software testing phase. However, it might not be appropriate to represent the consumption curve for testing effort by one of already proposed curves in some software development environments. Therefore, this paper shows that a logistic testing-effort function can be adequately expressed as a software development/testing effort curve and that it gives a good predictive capability based on real failure data.

• 한국산업정보학회논문지
• /
• 제17권3호
• /
• pp.27-34
• /
• 2012

This paper presents the impact of time dependent dielectric breakdown (TDDB, also called as gate oxide breakdown) failure on nanoscale digital CMOS Circuits. Recently, TDDB for ultra-thin gate oxides has been considered as one of the critical reliability issues which can lead to performance degradation or logic failures in nanoscale CMOS devices. Also, leakage power in the standby mode can be increased significantly. In this paper, TDDB aging effects on large CMOS digital circuits in the 45nm technology are analyzed. Simulation results show that TDDB effect on MOSFET circuits can result in more significant increase of power consumption compared to delay increase.

• 융합보안논문지
• /
• 제13권1호
• /
• pp.3-10
• /
• 2013

본 연구에서는 소프트웨어 제품 테스팅 과정에서 관측고장시간에 근거한 결함 발생률을 고려한 소프트웨어 신뢰성 모형에 대하여 연구 하였다. 신뢰성 분야에서 많이 사용되는 S-분포모형을 이용한 새로운 결함 확률을 추가한 문제를 제시하였다. 수명분포는 유한고장 비동질적인 포아송과정을 이용하였다 본 논문의 결함 발생률을 고려한 소프트웨어 고장 자료 분석에서는 고장 시간 자료를 적용하였으며 모수추정 방법은 최우추정법을 이용하여 결함 발생 확률에 대한 관계와 신뢰도를 추정 하였다.

• 정보처리학회논문지D
• /
• 제8D권6호
• /
• pp.835-842
• /
• 2001

본 논문에서는 소프트웨어 시험 단계중에 발생되는 시험노력 소요량을 고려한 소프트웨어 신뢰도 성장 모델을 제시하여 시간종속적인 시험 노력소요량 동태를 웨이블 곡선으로 설명한다. 시험 단계중에 소요되는 시험노력의 양에 대한 결함 검출비를 현재의 결함 내용에 비례하는 것으로 가정하여 소프트웨어 신뢰도 성장 모델을 비동차 포아송 프로세스(NHPP)로 공식화하되, 이 모델을 이용하여 소프트웨어 신뢰도 척도에 대한 데이터 분석기법을 개발한다. 시험 시간의 경과와 신뢰도와의 관계, 시험비용과 신뢰도와의 관계를 연구한다. 소프트웨어의 비용을 고찰함에 있어서 조건별로 검토하여 비용이 최소로 되는 발행시각을 결정하되, 목표신뢰도를 만족시키는 최적발행시각을 정한다. 비용의 입장에서 발행 시각을 결정하는 문제와 신뢰도의 입장에서 발행 시각을 결정하는 문제를 동시에 고려하여 최적 발행시각을 결정하도록 한다.