• Title/Summary/Keyword: 신뢰성(reliability)

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Reliability Updates of Driven Piles Based on Bayesian Theory Using Proof Pile Load Test Results (베이지안 이론을 이용한 타입강관말뚝의 신뢰성 평가)

  • Park, Jae-Hyun;Kim, Dong-Wook;Kwak, Ki-Seok;Chung, Moon-Kyung;Kim, Jun-Young;Chung, Choong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.161-170
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    • 2010
  • For the development of load and resistance factor design, reliability analysis is required to calibrate resistance factors in the framework of reliability theory. The distribution of measured-to-predicted pile resistance ratio was obrained based on only the results of load tests conducted to failure for the assessment of uncertainty regarding pile resistance and used in the conventional reliability analysis. In other words, successful pile load test (piles resisted twice their design loads without failure) results were discarded, and therefore, were not reflected in the reliability analysis. In this paper, a new systematic method based on Bayesian theory is used to update reliability indices of driven steel pipe piles by adding more proof pile load test results, even not conducted to failure, to the prior distribution of pile resistance ratio. Fifty seven static pile load tests performed to failure in Korea were compiled for the construction of prior distribution of pile resistance ratio. The empirical method proposed by Meyerhof is used to calculate the predicted pile resistance. Reliability analyses were performed using the updated distribution of pile resistance ratio. The challenge of this study is that the distribution updates of pile resistance ratio are possible using the load test results even not conducted to failure, and that Bayesian updates are most effective when limited data are available for reliability analysis.

Structural Reliability Evaluation on Solder Joint of BGA and TSSOP Components under Random Vibration using Reliability and Life Prediction Tool of Sherlock (신뢰성 수명예측 도구 Sherlock을 활용한 랜덤진동에서의 BGA 및 TSSOP 솔더 접합부의 구조 신뢰성 평가)

  • Park, Tae-Yong;Park, Jong-Chan;Park, Hoon;Oh, Hyun-Ung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.12
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    • pp.1048-1058
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    • 2017
  • One of the failure mechanism of spaceborne electronics is a fatigue fracture on solder joint under launch random vibration. Thus, a necessity of early diagnosis through the fatigue life evaluation on solder joint arises to prevent such potential risk of failure. The conventional life prediction methods cannot assure the accuracy of life estimation results if the packaging type changes, and also requires much time and effort to construct the analysis model of highly integrated PCB with various packaging types. In this study, we performed life prediction of PCB based on a reliability and life prediction tool of sherlock as a new approach for evaluating the structural reliability on solder joint, and those prediction results were validated by fatigue tests. In addition, we also investigated an influence of solder height on the fatigue life of solder joint. These results indicated that the Sherlock is applicable tool for evaluating the structural reliability of spaceborne electronic.

Embodying RBD and Reliability Analysis Technology base on Web (웹 기반 RBD 구현 및 신뢰도 평가기술)

  • 송준엽;이승우;이후상;조복기
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1541-1544
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    • 2003
  • In this study, embodying reliability block diagram based on the web and reliability analysis technology are developed. RBD(reliability Block Diagram) represents the functional relation between elements in any product. Among relations between elements. there are serial, parallel, bridge, and stand by, etc. Advantages of developed system are integrated datum about reliability (NPRD, EPRD, MIL-HDBK 217F, NSWC. OREDA. Bellcore, and domestic institutes & companies datum). graphic user interface for convenience, and the various service analyzes the failure history data of parts.

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Lifetime Prediction of Existing Highway Bridges Using System Reliability Approach (실제 교량의 시스템 신뢰성해석에 기초한 수명예측)

  • Yang, Seung Ie
    • Journal of Korean Society of Steel Construction
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    • v.14 no.2
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    • pp.365-373
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    • 2002
  • In this paper, the system reliability concept was presented to predict the lifespan of bridges. Lifetime distribution functions (survivor functions) were used to model real bridges to predict their remaining life. Using the system reliability concept and lifetime distribution functions (survivor functions), a program called LIFETIME was developed. The survivor functions give the reliability of component at time t. The program was applied to an existing Colorado state highway bridge to predict the failure probability of the time-dependent system. The bridge was modeled as a system, with failure probability computed using time-dependent deteriorating models.

Reliability Assessment Criteria of Air Quality System (자동차용 유해가스 검출기의 신뢰성 평가기준)

  • Choi, Man-Yeop;Park, Dong-Kyu;Oh, Geun-Tae;Jeong, Hai-Sung
    • Journal of Applied Reliability
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    • v.10 no.4
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    • pp.279-297
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    • 2010
  • AQS(Air Quality Control System) is the important part of a car air conditioning system. This device intercepts automatically the influx of harmful waste gas. In this paper reliability assessment criteria for AQS are established in terms of quality certification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.

A Study on Reliability Terms and Specifications between South and North Koreas (남북한 신뢰성 용어 및 규격 비교)

  • Jeong, Hai-Sung;Kim, Kuk
    • Journal of Applied Reliability
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    • v.8 no.1
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    • pp.29-37
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    • 2008
  • The technology of North Korea has not reached the modem level even though it has economic potential. Standardization and quality control have comprehensively prevailed in South Korea since the 1970s, which is considered to have been based of quality improvement. In the course of an active interchange between South and North, it is necessary to grasp the phenomenon on the quality and reliability control of North Korea. This study will put its relevant terms in order and make a comparison between specifications of North Korea and South Korea in the reliability test plans.

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A Study for Domain Categorization and Estimation of Complexity for Reliability Improvement of Domain Analysis (도메인 분석의 신뢰성 향상을 위한 도메인 분류와 복잡도 측정에 관한 연구)

  • Lee, Eun-Ser
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.1
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    • pp.1-6
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    • 2016
  • Domain analysis is an important component for reliability of development project. Domain analysis error have an effect in the whole system. As a result, the system reliability will be deteriorated. Therefore, we need a methodology to analyze domain characteristic for a reliable analysis in the domain analysis phase. In this paper, we propose a methodology for domain categorization and estimation of complexity for reliability improvement of domain analysis.