• International Journal of Reliability and Applications
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• 제14권2호
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• pp.107-114
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• 2013

Modelling of failures is an important element of reliability modelling. Empirical modelling approach suitable for complex item is explored in this paper. First step of the empirical modelling approach is to plot hazard function, density function, Weibull probability plot as well as cumulative intensity function to see which model fits best for the given data. Next step of the empirical modelling approach is select appropriate model for the data and fit the parametric model accordingly and estimate the parameters.

• Communications for Statistical Applications and Methods
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• 제16권2호
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• pp.349-361
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• 2009

In this paper, we derive the approximate maximum likelihood estimators of the shape parameter and the scale parameter in a Weibull distribution under multiply Type-II censoring by the approximate maximum likelihood estimation method. We develop three modified empirical distribution function type tests for the Weibull distribution based on multiply Type-II censored samples. We also propose modified normalized sample Lorenz curve plot and new test statistic.

• 한국공작기계학회논문집
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• 제12권4호
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• pp.9-16
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• 2003

In this study, the decision of dressing time for diamond wheel was analyzed by observing with acoustic emission signals and surface roughness, and also obtained the machining characteristics by weibull distribution plot for the values of bending strength. From the experimental study, it was possible to predict the time of re-dressing for the diamond grinding wheel with the analysis of acoustic emission signals and surface roughness values, and following conclusions were obtained. The root-mem-square values of acoustic emission signals were obtained low as the increased of table speed for different abrasive grain size. This is caused by the lack of grinding power which is not able to get rid of all real grinding mass of depth as the table speed is increased. The values of bending strength for ground $Si_3 N_4$ specimens were decreased for gain size of #400 than that of #60, but it was found that the surface roughness values for gain size of #60 were better than that of #400. As compared the shape parameter of weibull distribution plot for the values of bending strength, it was found that the reliability of bending strength for grain size of #60 increased than that of #400.

• Journal of the Korean Data and Information Science Society
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• 제25권4호
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• pp.903-914
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• 2014

The inverse Weibull distribution has been proposed as a model in the analysis of life testing data. Also, inverse Weibull distribution has been recently derived as a suitable model to describe degradation phenomena of mechanical components such as the dynamic components (pistons, crankshaft, etc.) of diesel engines. In this paper, we derive the approximate maximum likelihood estimators of the scale parameter and the shape parameter in the inverse Weibull distribution under multiply type-II censoring. We also develop four modified empirical distribution function (EDF) type tests for the inverse Weibull or extreme value distribution based on multiply type-II censored samples. We also propose modified normalized sample Lorenz curve plot and new test statistic.

• 한국세라믹학회지
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• 제36권10호
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• pp.1069-1074
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• 1999

• 열처리공학회지
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• 제26권4호
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• pp.178-184
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• 2013

The effects of thickness and surface grinding condition on the fracture strength of Si wafer with a thickness under $100{\mu}m$ were investigated. Fracture strength was measured by ball breaker test for about 330 dies (size: $4mm{\times}4mm$) per each wafer. For statistical analysis of the fracture strength, scale factor was determined from Weibull plot. Ball breaker fracture strength was observed to increase with decreasing thickness of silicon die. For the silicon dies of different surface conditions, ball breaker fracture strength was high in the order of polished, ground (#4800), and ground (#320 grit) specimen. Probabilistic fracture strength (i.e., scale factor) increased with decreasing surface roughness of silicon die.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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• pp.32-32
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• 2010

A epoxy/multilayered silicate nanocomposite was prepared by a new AC electric application method and micro silica particle was poured into the nanocomposite in order to prepare epoxy/micro-and-nano- mixed composites (EMNC). Electric insulation breakdown strength was measured in a sphere-sphere electrode system designed for the prevention of edge breakdown and the data were estimated by Weibull plot. As the exfoliated silicate nano-plates were homogeniously dispersed in the micro silica particles, the insulation property was higherd.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1378_1380
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• 2009

절연파괴 강도에대한 특성분석을 위해 와이블 plot을 이용하였다. ENMMC에서 실란처리와 미처리특성에서 실란처리된 결과 형상파라미터가 상대적으로 높은 값을 나타내었다. 이는 절연파괴결과가 균질함을 분명하게 나타낸 결과이다. 또한 스케일파리미터에서도 처리된 결과가 상대적으로 높은 결과를 보이고 있다. 나노입자 충진함량에 대한 효과에서도 체적비로 6.2vol%가 24.87vol%보다 월등하게 높은 형상파리미터와 스케일 파리미터를 나타내었다. 현장에서는 B10의 수명이 누적확률(63.2%)보다 오히려 유효한 평가자료 라고 사료된다. 역시 실란처리 된 결과가 미처리된 것에 비하여 그리고 나노입자 충진함량이 적을수록 높은 결과를 나타내었다. 이로서 중전기기 산업절연재료로서 향후 전망을 크게 할 것으로 본다.

• 한국생산제조학회지
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• 제19권6호
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• pp.804-811
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• 2010

The fatigue crack propagation is stochastic in nature, because the variables affecting the fatigue behavior are random and have uncertainty. Therefore, the fatigue life prediction is critical for the design and the maintenance of many structural components. In this study, fatigue experiments are conducted on the specimens of magnesium alloy AZ31 under various conditions such as thickness of specimen, the load ratio and the loading condition. The probability distribution fit to the fatigue failure life are investigated through a probability plot paper by these conditions. The probabilities of failure at various conditions are also estimated. The fatigue design life is predicted by using the Weibull distribution.

• 한국식품저장유통학회지
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• 제18권3호
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• pp.423-428
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• 2011

주요 식중독균인 E. coli O157:H7, L monocytogenes, S. aureus, S. Typhimurium과 S. Enteritidis를 주어진 이산화염소수 농도에서 시간별로 처리한 inactivation data를 first-order kinetic model과 Weibull model을 이용하여 kinetic parameter를 비교, 분석하였다. 그 결과 Weibull model이 first-order kinetic model보다 inactivation kinetic data에 더 적합한 것을 보였다. 또한 특정 농도의 이산화염소수에서 처리한 survival plot의 tR values(특정 이산화염소수 농도에서 미생물 90%를 감소시키기 위해 필요한 시간)는 Weibull model을 적용 시, E. coli O157:H7가 5 ppm에서 2.49 min, L. monocytogenes가 5 ppm에서 1.47 min, S. aureus가 5 ppm에서 0.94 min, S. Typhimurium이 1 ppm에서 0.87 min 그리고 S. Enteritidis가 1 ppm에서 0.08 min으로 측정 되었다.