• Title/Summary/Keyword: Life testing

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Prediction Models for Corrosion of Reinforcing Bars (철근의 부식 예측 모델에 관한 연구)

  • 김도겸;이종석;고경택;이장화;송영철;조명석
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.739-742
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    • 1999
  • A reinforcement corrosion prediction model was proposed using the results from accelerated testing and mathematical equation from the Fick's 2nd law for chloride-induced corrosion of reinforcement in concrete. The input data included the chloride concentration, mix characteristics of concrete, and environmental conditions. This model can be used to predict the chloride concentration pertaining to corrosion time and loading age for marine concrete structures. This model can also be used to predict the service life.

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A Comparative Study on Nonparametric Reliability Estimation for Koziol-Green Model with Random Censorship

  • Cha, Young-Joon;Lee, Jae-Man
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.231-237
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    • 1997
  • The Koziol-Green(KG) model has become an important topic in industrial life testing. In this paper we suggest MLE of the reliability function for the Weibull distribution under the KG model. Futhermore, we compare Kaplan-Meier estimator, Nelson estimator, Cheng & Chang estimator, and Ebrahimi estimator with proposed estimator for the reliability function under the KG model.

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Some Distribution Free Tests for Exponential Distributions

  • Jeon, Jong Woo;Han, Suk Ki;Nam, Eun Woo
    • Journal of Korean Society for Quality Management
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    • v.14 no.1
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    • pp.39-46
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    • 1986
  • This paper considers two sided tests for exponential null distribution against NBUE or NWUE alternative in life testing. The main results concern the strong consistency of two proposed statistics, one being similar to Kolmogorov - Smirnov statistic, the other similar to Cramer-Von Mises statistic. Also obtained are the asymtotic null distribution and the exact Bahadur slope of the statistic similar to Kolmogorov-Smirnov.

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Sequential Estimation in Exponential Distribution

  • Park, Sang-Un
    • Communications for Statistical Applications and Methods
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    • v.14 no.2
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    • pp.309-316
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    • 2007
  • In this paper, we decompose the whole likelihood based on grouped data into conditional likelihoods and study the approximate contribution of additional inspection to the efficiency. We also combine the conditional maximum likelihood estimators to construct an approximate maximum likelihood estimator. For an exponential distribution, we see that a large inspection size does not increase the efficiency much if the failure rate is small, and the maximum likelihood estimator can be approximated with a linear function of inspection times.

Erratum

  • 대한한방신경정신과학회
    • Journal of Oriental Neuropsychiatry
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    • v.24 no.3
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    • pp.321-330
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    • 2013
  • Voice Handicap Index and Voice-Related Quality of Life in Idiopathic Parkinson's Disease 10.7231/jon.2013.24.2.155, The Differences of Learning Characteristics in Sasang Constitution 10.7231/jon.2013.24.2.163, A Preliminary Comparison of the Efficacy of Auricular Acupuncture, Transdermal Nicotine Patch and Combination Therapy for Smoking Cessation 10.7231/jon.2013.24.2.179, The Effects of OnDam-tang-Kami-bang (ODK) in Antioxidant and Serotonin Metabolism Testing on P815 Cell 10.7231/jon.2013.24.2.189

A new test of exponentiality against NDVRL

  • Hassan, M.KH.
    • International Journal of Reliability and Applications
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    • v.16 no.2
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    • pp.123-133
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    • 2015
  • In this paper, the problem of testing exponentiality against net decreasing variance residual lifetime (NDVRL) classes of life distributions is investigated. For this property a nonparametric test is presented based on kernel method. The test is presented for complete and right censored data. Furthermore, Pitman's asymptotic relative efficiency (PARE) is discussed to assess the performance of the test with respect to other tests. Selected critical values are tabulated. Some numerical simulations on the power estimates are presented for proposed test. Finally, numerical examples are presented for the purpose of illustrating our test.

Mold Base Structure and Standardization for Recycling (몰드베이스의 재활용을 위한 구조 및 규격화)

  • 정영득;송준엽;한성렬;제덕근
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.373-376
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    • 2000
  • Recently, the life cycle of products is rapidly shortened and then the W s a l of the used mold applied in development of a product is a difficult things. In this study, we proposed a feasibility of the recycling mold base by analyzing of the existing standard mold base. And we developed a D/B program to promote the mold design capability with CAD. Also, we confirmed the possibility of recycling mold base by testing of a used automobile lamp mold.

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Statistical Inferences for Bivariare Exponential Distribution in Reliability and Life Testing Problems

  • PARK, BYUNG-GU
    • Journal of Korean Society for Quality Management
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    • v.13 no.1
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    • pp.31-40
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    • 1985
  • In this paper, statistical estimation of the parameters of the bivariate exponential distribution are studied. Bayes estimators of the parameters are obtained and compared with the maximum likelihood estimators which are introduced by Freund. We know that the method of moments estimators coincide with the maximum likelihood estimators and Bayes estimators are more efficient than the maximum likelihood estimators in moderate samples. The asymptotic distributions of the maximum likelihood estimators and the estimator of mean time to system failure are obtained.

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First Report of Rhizopus oryzae as a Postharvest Pathogen of Apple in Korea

  • Kwon, Jin-Hyeuk;Kim, Jin-Woo;Kim, Won-Il
    • Mycobiology
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    • v.39 no.2
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    • pp.140-142
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    • 2011
  • Soft rot in apple caused by Rhizopus oryzae was found for the first time in Korea. A detailed description of the specimen is given along with its internal transcribed spacer rDNA sequence. The fungus was identified as Rhizopus oryzae based on the mycological characteristics, molecular data, and pathogenicity testing.

가속 수명시험을 이용한 벌크샘플링 설계에 관한 연구

  • Park, Uk-Je;Kim, Jong-Geol
    • Proceedings of the Safety Management and Science Conference
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    • 2006.11a
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    • pp.255-267
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    • 2006
  • 제품을 로트(lot)단위로 구분하고 로트에서 취한 샘플을 검사하여 얻은 품질 특성의 값을 이용해서 로트의 합격여부를 판정하는 것을 샘플링검사(sampling inspection)라 하고, 검사하는 품질특성이 제품의 수명 특성치인 경우에 이를 신뢰성 샘플링 검사(reliability sampling inspection)라 한다. 그 중 벌크재료에 대한 샘플링 검사방식을 알아 보도록한다.

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