• 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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    • 2003.06a
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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 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.

Development of Comparative Verification System for Reliability Evaluation of Distribution Line Load Prediction Model (배전 선로 부하예측 모델의 신뢰성 평가를 위한 비교 검증 시스템)

  • Lee, Haesung;Lee, Byung-Sung;Moon, Sang-Keun;Kim, Junhyuk;Lee, Hyeseon
    • KEPCO Journal on Electric Power and Energy
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    • v.7 no.1
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    • pp.115-123
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    • 2021
  • Through machine learning-based load prediction, it is possible to prevent excessive power generation or unnecessary economic investment by estimating the appropriate amount of facility investment in consideration of the load that will increase in the future or providing basic data for policy establishment to distribute the maximum load. However, in order to secure the reliability of the developed load prediction model in the field, the performance comparison verification between the distribution line load prediction models must be preceded, but a comparative performance verification system between the distribution line load prediction models has not yet been established. As a result, it is not possible to accurately determine the performance excellence of the load prediction model because it is not possible to easily determine the likelihood between the load prediction models. In this paper, we developed a reliability verification system for load prediction models including a method of comparing and verifying the performance reliability between machine learning-based load prediction models that were not previously considered, verification process, and verification result visualization methods. Through the developed load prediction model reliability verification system, the objectivity of the load prediction model performance verification can be improved, and the field application utilization of an excellent load prediction model can be increased.

Life Analysis of Relays based on Life Prediction Method (수명예측 방법에 따른 계전기의 수명분석)

  • Shin, Kun-Young;Lee, Duk-Gyu;Lee, Hi Sung
    • Journal of the Korean Society of Safety
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    • v.27 no.4
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    • pp.115-120
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    • 2012
  • In order to establish preventive maintenance standards through analysis & reliability prediction of about 60,000pcs of 20kindsof relays and contractors used for Seoul subway trains, several life prediction methodologies were applied. Firstly, Occurrence, Severity, Detection were defined and predicted by applying operation characteristic of EMU to the number of actions of relays & contactors which the manufacturers generally offer as the life cycle data. Secondly, failure distribution and average life of parts were analyzed through interpretation of field data based on a lot of experience which had built up in the field for a long time. Finally, using the 217PLUS standard as a reliability prediction program, comparative analysis of use reliability and inherent reliability was done through reliability prediction at the part level and system level.

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 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 s.36
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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.