http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이주현,안선응,Lee, Juhyun,Ahn, Suneung 한국신뢰성학회 2018 신뢰성응용연구 Vol.18 No.2
Purpose: This paper proposes the non-periodic preventive maintenance policy based on the level of cumulative hazard intensity. We aim to construct a cost-effectiveness on the proposed model with relaxing the constraint on reliability. Methods: We use the level of cumulative hazard intensity as a condition variable, instead of reliability. Such a level of cumulative hazard intensity can derive the reliability which decreases as the frequency of preventive maintenance action increases. We also model the imperfect preventive maintenance action using the proportional age setback model. Conclusion: We provide a numerical example to illustrate the proposed model. We also analyze how the parameters of our model affect the optimal preventive maintenance policy. The results show that as long as high reliability is guaranteed, the inefficient preventive maintenance action is performed reducing the system operation time. Moreover, the optimal value of the proposed model is sensitive to changes in preventive maintenance cost and replacement cost.
김현묵(Hyunmook Kim),안선응(Suneung Ahn) 한국산업경영시스템학회 2005 한국산업경영시스템학회지 Vol.28 No.3
This paper is intended to compare the hazard rate estimations from Bayesian approach and maximum likelihood estimate(MLE) method. Hazard rate frequently involves unknown parameters and it is common that those parameters are estimated from observed data by using MLE method. Such estimated parameters are appropriate as long as there are sufficient data. Due to various reasons, however, we frequently cannot obtain sufficient data so that the result of MLE method may be unreliable. In order to resolve such a problem we need to rely on the judgement about the unknown parameters. We do this by adopting the Bayesian approach. The first one is to use a predictive distribution and the second one is a method called Bayesian estimate. In addition, in the Bayesian approach, the prior distribution has a critical effect on the result of analysis, so we introduce the method using computerized-simulation to elicit an effective prior distribution. For the simplicity, we use exponential and gamma distributions as a likelihood distribution and its natural conjugate prior distribution, respectively. Finally, numerical examples are given to illustrate the potential benefits of the Bayesian approach.
자동차 구동축 소음 저감을 위한 신뢰성 개선프로세스의 개발
윤혁춘(Hyukchoon Yun),안선응(Suneung Ahn),배석주(Suk Joo Bae) 한국신뢰성학회 2020 신뢰성응용연구 Vol.20 No.4
Purpose: Securing reliability of the components in automobiles is a key issue. The purpose of this research is to develop a step-by step process for reliability improvement using accelerated tests to reduce the noises from the drive shafts in automobiles. Methods: The step-by-step reliability improvement process includes problem definition, reliability test planning, executing an accelerated test, reliability analysis, deriving an improvement scheme, and making a reliability qualification standard. Results: A real case study shows that the proposed process can reduce the noises from the drive shafts by identifying the failure causes and mechanisms through material tests and bench tests. Finally, intended reliability target is proved to be satisfied by quantitative reliability analysis. Conclusion: Reliability improvement can be realized by establishing the systematic reliability evaluation process. We expected that the proposed reliability improvement process can be widely applied to other components in automobiles or other industries to establish the reliability management policy.
자진신고자 감면제도하의 담합 게임에 대한 균형분석모형 개발
박지현(Jihyun Park),안선응(Suneung Ahn) 한국산업경영시스템학회 2013 한국산업경영시스템학회지 Vol.36 No.4
This study is to develop a mathematical analysis model to grasp the behaviors of cartels. Cartels are formed tacitly and cause tremendous damage to consumers in modem society which is composed of advanced industry structure. The government authorities have instituted the leniency programs to respond cartels. However, cartels will continue unless there are legal sanctions against cartels based on an accurate analysis of leniency programs. The proposed cartel equilibrium analysis model is a mathematical behavior model which is based on the existing methods and the prison's dilemma of game theory. Therefore, the model has a form of pay off matrix of two players. We use a iterated polymatrix approximation (IPA) method to deduct a Nash equilibrium point. The model is validated by an empirical analysis as well.
베타-이항분포의 공액성을 근거로 한 유한 모집단의 신뢰성 입증 시험
전종선(Jongseon Jeon),안선응(Suneung Ahn) 한국산업경영시스템학회 2012 한국산업경영시스템학회지 Vol.35 No.2
This paper describes the Bayesian approach for reliability demonstration test based on the samples from a finite population. The Bayesian approach involves the technical method about how to combine the prior distribution and the likelihood function to produce the posterior distribution. In this paper, the hypergeometric distribution is adopted as a likelihood function for a finite population. The conjugacy of the beta-binomial distribution and the hypergeometric distribution is shown and is used to make a decision about whether to accept or reject the finite population judging from a viewpoint of faulty goods. A numerical example is also given.
프로젝트 리스크 관리를 위한 신뢰도 함수 기반 수리모형 개발
한선하(Seonha Han),전종선(Jongseon Jeon),안선응(Suneung Ahn) 한국SCM학회 2015 한국SCM학회지 Vol.15 No.1
In this paper, a mathematical model is developed for finding a degree of influence of risk factors affecting the project activity. After risks of project activities are identified, influence of risk factors are evaluated based on AHP(Analytic Hierarchy Process). All identified risk factors are structured in forms of block diagrams. Reliability functions are derived based on block diagrams of risk factors and represents the probability of the project activity success. Based on the derived reliability functions, structural impact is calculated as a criterion for expressing a degree of influence of each risk affecting the fail of the project activities. Structural risk includes the structural impact and the probability of risk. It could be applied to determine the priorities of risks which should be controlled, and the use of such priorities could guarantee successful project activities. Finally, numerical examples of the proposed mathematical models are also given.