• Title, Summary, Keyword: Reliability Prediction

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Reliability Prediction & Design Review for Core Units of Machine Tools (공작기계 핵심 Units의 신뢰성 예측 및 Design Review)

  • 이승우;송준엽;이현용;박화영
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.133-136
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    • 2003
  • In these days, the reliability analysis and prediction are applied for many industrial products and many products require guaranteeing the quality and efficiency of their products. In this study reliability prediction for core units of machine tools has been performed in order to improve and analyze its reliability. ATC(Automatic Tool Changer) and interface Card of PC-NC that are core component of the machine tools were chosen as the target of the reliability prediction. A reliability analysis tool was used to obtain the reliability data(failure rate database) for reliability prediction. It is expected that the results of reliability prediction be applied to improve and evaluate its reliability. Failure rate, MTBF (Mean Time Between Failure) and reliability for core units of machine tools were evaluated and analyzed in this study.

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Reliability prediction of electronic components on PCB using PRISM specification (PRISM 신뢰성 예측규격서를 이용한 전자부품(PCB) 신뢰도 예측)

  • Lee, Seung-Woo;Lee, Hwa-Ki
    • Journal of the Korea Safety Management & Science
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    • v.10 no.3
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    • pp.81-87
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    • 2008
  • The reliability prediction and evaluation for general electronic components are required to guarantee in quality and in efficiency. Although many methodologies for predicting the reliability of electronic components have been developed, their reliability might be subjective according to a particular set of circumstances, and therefore it is not easy to quantify their reliability. In this study reliability prediction of electronic components, that is the interface card, which is used in the CNC(Computerized Numerical Controller) of machine tools, was carried out using PRISM reliability prediction specification. Reliability performances such as MTBF(Mean Time Between Failure), failure rate and reliability were obtained, and the variation of failure rate for electronic components according to temperature change was predicted. The results obtained from this study are useful information to consider a counter plan for weak components before they are used.

A methodology for creating a function-centered reliability prediction model (기능 중심의 신뢰성 예측 모델링 방법론)

  • Chung, Yong-ho;Park, Ji-Myoung;Jang, Joong-Soon;Park, Sang-Chul
    • Journal of the Korea Society for Simulation
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    • v.25 no.4
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    • pp.77-84
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    • 2016
  • This paper proposes a methodology for creating a function based reliability prediction model. Although, there are various works for reliability prediction, one of the features of their research is that the research is based on hardware-centered reliability prediction. Reliability is often defined as the probability that a device will perform its intended function, under operating condition, for a specified period of time, there is a profound irony about reliability prediction problem. In this paper, we proposed four-phase modeling procedure for function-centered reliability prediction. The proposed modeling procedure consists of four models; 1) structure block model, 2) function block model, 3) device model, and 4) reliability prediction model. We performed function-centered reliability prediction for electronic ballast using the proposed modeling procedure and MIL-HDBK-217F which is the military handbook for reliability prediction of electronic equipment.

Reliability evaluation plan of Rocket motor system (고체 추진기관 시스템의 신뢰성 평가 방안)

  • Kwon, Tag-Man;Jung, Ji-Sun;Shim, Hang-Geun;Jang, Ju-Su
    • Journal of Applied Reliability
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    • v.11 no.4
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    • pp.399-407
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    • 2011
  • Reliability evaluation of One-Shot system which flies at speed of Mach must be evaluated as the result of many firing tests. But many firing tests are impossible because of budget deficit. Consequently the reliability prediction which substitutes firing tests is used. The accuracy of reliability prediction is decided according to a quantity of accumulated test data. If the test data is insufficient, the direction of prediction can not be set. So we propose the reliability prediction method which applies MIL-HDBK-217 Plus. MIL-HDBK-217 Plus is described about reliability prediction method without sufficient test data. So we apply MIL-HDBK-217 Plus to the rocket motor system, and we accomplish a modeling and a reliability prediction about the system.

Reliability Prediction for the DSP module in the SMART Protection System (일체형 원자로 보호계통의 디지털 신호 처리 모듈에 대한 신뢰도 예측)

  • Lee, Sang-Yong;Jung, Jae-Hyun;Kong, Myung-Bock
    • IE interfaces
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    • v.21 no.1
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    • pp.85-95
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    • 2008
  • Reliability prediction serves many purposes during the life of a system, so several methods have been developed to predict the parts and systems reliability. MIL-HDBK-217F, among the those methods, has been widely used as a requisite tool for the reliability prediction which is applied to nuclear power plants and their safety regulations. This paper presents the reliability prediction for the DSP(Digital Signal Processor) module composed of three assemblies. One of the assemblies has a monitoring and self test function which is used to enhance the module reliability. The reliability of each assembly is predicted by MIL-HDBK-217F. Based on these predicted values, Markov modelling is finally used to predict the module reliability. Relax 7.7 software of Relax software corporation is used because it has many part libraries and easily handles Markov processes modelling.

Reliability Prediction Based Reliability Growth Management : Case Study of Surveillance System (신뢰도 예측 기반 신뢰도 성장 관리 : 감시체계 사례)

  • Kim, SB;Park, WJ;You, JW;Lee, JK;Yong, HY
    • Journal of the Korean Society for Quality Management
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    • v.47 no.1
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    • pp.187-198
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    • 2019
  • Purpose: In this study, a reliability prediction based reliability growth management is suggested especially for the early development phase of a system and the case study of surveillance system is given. Methods: The proposed reliability prediction based reliability growth management procedures consists of 7 Steps. In Step 1, the stages for reliability growth management are classified according to the major design changes. From Step 2 to Step 5, system reliability is predicted based on reliability structures and the predicted reliabilities of subsystems (Level 2) and modules (Level 3). At each stage, by comparing the predicted system reliability with that of the previous stage, the reliability growth of the system is checked in Step 6. In Step 7, when the predicted value of sustem reliability does not satisfy the reliability goal, some design alternatives are considered and suggested to improve the system reliability. Results: The proposed reliability prediction based reliability growth management can be an efficient alternative for managing reliability growth of a system in its early development phase. The case study shows that it is applicable to weapon system such as a surveillance system. Conclusion: In this study, the procedures for a reliability prediction based reliability growth management are proposed to satisfy the reliability goal of the system efficiently. And it is expected that the use of the proposed procedures would reduce, in the test and evaluation phase, the number of corrective actions and its cost as well.

Reliability Prediction Based on Field Failure Data of Guided Missile (필드데이터 기반의 유도탄 신뢰도 예측)

  • Seo, Yangwoo;Lee, Kyeshin;Lee, Younho;Kim, Jeyong
    • Journal of Applied Reliability
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    • v.18 no.3
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    • pp.250-259
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    • 2018
  • Purpose: Previously, missile reliability prediction is based on theoretical failure prediction model. It has shown that the predicted reliability is inadequate to real field data. Although an MTTF based reliability prediction method using real field data has recently been studied to overcome this issue. In this paper, we present a more realistic method, considering MTBF concept, to predict missile reliability. Methods: In this paper we proposed a modified survival model. This model is considering MTBF as its core concept, and failed missiles in the model are to be repaired and redeployed. We compared the modified model (MTBF) and the previous model (MTTF) in terms of fitness against the real failure data. Results: The reliability prediction result of MTBF based model is closer to fields failure data set than that of MTTF based model. Conclusion: The proposed MTBF concept is more fitted to real failure data of missile than MTTF concept. The methodology of this study can be applied to analyze field failure data of other similar missiles.

A Study on the Aircraft Mission Reliability Prediction (항공기 임무신뢰도 예측 방안 연구)

  • Lee Joon-Woo;Ju Hyun-Joon;Lee Min-Koo
    • Journal of Applied Reliability
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    • v.6 no.2
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    • pp.115-134
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    • 2006
  • This paper deals with OO aircraft mission reliability prediction. To demonstrate user-required mission reliability, it is calculated with use general formulae which are used in reliability engineering. The mission reliability of OO aircraft is calculated in considering conversion factor (CF) on the each subsystems' MTBF. The prediction results are explained only the state at present time. Because these data are not real data in operational environments. Therefore, in the case of OO aircraft, it has to be needed collecting the real and renewal data which are operational and empirical. After that, continuing the data upgrading, it is easily closed to the more exact reliability value.

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A Study on the Reliability of Software for Railway Signalling Systems (철도신호제어용 소프트웨어 신뢰도 모델링에 관한 연구)

  • Lee, Jae-Ho;Park, Young-Soo
    • Journal of the Korean Society for Railway
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    • v.9 no.5
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    • pp.601-605
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    • 2006
  • Reliability of the Railway signaling system which is safety critical is determined by reliability of hardware and software. Reliability of hardware is easily predicted and demonstrated through lots of different studies and environmental tests, while that of software is estimated by the iterative test outcomes so estimates of reliability will depend on the inputs. Combinations of inputs to and outputs from the software may be mostly combinatoric and therefore all the combinations could not be tested. As a result, it has been more important to calculate reliability by means of a simpler method. This paper identifies the reliability prediction equation applicable to reliability prediction for railway signaling system software, and performs the simulation of onboard equipment of automatic train control for high speed train to review reliability prediction and validity.

Reliability Prediction for VDI Turret (VDI Turret의 신뢰도 예측)

  • Lee Seung-Woo;Lee Hwa-Ki
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.28 no.1
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    • pp.49-54
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    • 2005
  • Recently, the reliability are applied for many industrial products, and many products are required to guarantee in quality and in performance. The purpose of this paper is to present some of reliability prediction methodologies using failure rate database for machinery parts that are applicable to machine tools. VDI Turret, which is core component of the NC Lathe, was chosen as the target of the reliability prediction. The results of reliability prediction has shown the failure rate, MTBF(Mean Time Between Failure), and reliability of the VDI Turret. It is expected that proposed methodologies will be applicable to prediction of reliability for other components of machine tools.