A Comparison of Two Accelerated Degradation Models with Temperature and Humidity as Accelerating Stresses

2013 ◽  
Vol 300-301 ◽  
pp. 1162-1170 ◽  
Author(s):  
Wen Yu Wang ◽  
Xiao Bing Ma ◽  
Shi Hua Chang ◽  
Rui Kang
Keyword(s):  
Model Parameters ◽  
Ratio Test ◽  
Arrhenius Model ◽  
Joint Stress ◽  
Nested Models ◽  
Accelerated Degradation ◽  
Accelerated Life ◽  
Temperature And Humidity ◽  
Degradation Models ◽  
Eyring Model

In this paper, a comparison of two kinds of acceleration models under temperature and humidity joint stress is given. The traditional generalized Arrhenius model and Eyring Model give two ways to describe the accelerated life of products. First, through some mathematical transformation and synthesizing of these two models we have concluded two acceleration models under temperature and humidity joint stress which are described in detail in this paper. Estimations of model parameters are also given. Secondly, by comparing accelerated life coefficient and coefficient of variations, we can take a glimpse of the models in their fitness of actual conditions. Then, since the models presented in this paper follow the features of nested models, a likelihood ratio test is conducted which takes a further step in the work of model selection. At last, these two models are compared through an application example – Smart Electricity Meter.

Design of Accelerated Degradation Test Method and Failure Analysis of Flexible Hybrid Electronic Devices

2020 ◽  
Author(s):  
Alex Davila-Frias ◽  
Val Marinov ◽  
Om Prakash Yadav ◽  
Yuriy Atanasov
Keyword(s):  
Failure Analysis ◽  
Failure Process ◽  
Electronic Devices ◽  
Test Method ◽  
Stress Factors ◽  
Accelerated Degradation ◽  
Failure Data ◽  
Degradation Data ◽  
Accelerated Life ◽  
Temperature And Humidity

Abstract Accelerated life testing (ALT) has been a common choice to study the effects of environmental stresses on flexible hybrid electronics (FHE), a promising technology to produce flexible electronic devices. Nevertheless, accelerated degradation testing (ADT) has proven to be a more effective approach, which does not require failure occurrences, allowing shorter testing times. Since FHE devices are expected to be highly reliable, ADT provides useful information in the form of degradation data for further analysis without actual failure data. In this paper, we present the design and experimental setup of ADT for FHE considering two stress factors simultaneously. We use daisy-chain resistance as a measurable degradation characteristic to periodically monitor the degradation of FHE products under accelerated stress conditions. Two stress factors, temperature and humidity, are considered and ADT was carried out considering four combinations of temperature and humidity simultaneously. Failure analysis was performed on failed units to investigate the failure process and location of the failure. The ADT data was used to fit in the appropriate mathematical degradation model representing the failure process. The data analysis showed faster degradation paths for higher stress combinations. Finally, we present insights and further research opportunities to expand the work.

Study of High-Power White LED's Lifetime Based on Accelerated Life Test

2013 ◽  
Vol 800 ◽  
pp. 205-209 ◽  
Author(s):  
De Sheng Li ◽  
Nian Yu Zou ◽  
Yun Cui Zhang ◽  
Xiao Yang He ◽  
Yi Yang
Keyword(s):  
High Power ◽  
Accelerated Life Test ◽  
Reliability Test ◽  
White Led ◽  
Life Test ◽  
Arrhenius Model ◽  
White Leds ◽  
Accelerated Life ◽  
Temperature Levels

The study of LED reliability becomes more and more important with LED widely used in various areas, and accelerated life test (ALT) as an element of reliability test is widely used to predict the lifetime of LED. In this paper, ALTs have been carried out at various current levels and various temperature levels. In the current ALT experiment, three kinds of stressing currents were demonstrated for 1W white LEDs and lumen flux of the tested LEDs were studied, and based on Eyting model, lifetime of the tested LEDs is calculated about 6.86×105h. In the temperature ALT experiment, two kinds of stressing temperature were demonstrated for the same type of white LEDs and lumen flux were also studied, and based on Arrhenius model, lifetime of the tested LEDs is calculated about 7.41×105h. In addition, the color shifting velocity is faster than lumens depreciation velocity was observed in our experiment, which means the lifetime evaluating of white LED should be paid more attention.

Lifetime Estimation of a Photovoltaic Module Subjected to Corrosion Due to Damp Heat Testing

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
R. Laronde ◽  
A. Charki ◽  
D. Bigaud
Keyword(s):  
Crystalline Silicon ◽  
Meteorological Data ◽  
Photovoltaic Module ◽  
Model Parameters ◽  
Solar Panels ◽  
Power Requirement ◽  
Pv Module ◽  
Accelerated Life ◽  
Mean Lifetime ◽  
Initial Power

In this paper, a methodology is presented for estimating the lifetime of a photovoltaic (PV) module. Designers guarantee an acceptable level of power (80% of the initial power) up to 25 yr for solar panels without having sufficient feedback to validate this lifetime. Accelerated life testing (ALT) can be carried out in order to determine the lifetime of the equipment. Severe conditions are used to accelerate the ageing of components and the reliability is then deduced in normal conditions, which are considered to be stochastic rather than constant. Environmental conditions at normal operations are simulated using IEC 61725 standard and meteorological data. The mean lifetime of a crystalline-silicon photovoltaic module that meets the minimum power requirement is estimated. The main results show the influence of lifetime distribution and Peck model parameters on the estimation of the lifetime of a photovoltaic module.

Calibration of microscopic traffic-flow models using multiple data sources

2010 ◽  
Vol 368 (1928) ◽  
pp. 4497-4517 ◽  
Author(s):  
Serge Hoogendoorn ◽  
Raymond Hoogendoorn
Keyword(s):  
Driving Simulator ◽  
Likelihood Estimation ◽  
Joint Estimation ◽  
Data Sources ◽  
Parameter Estimates ◽  
Model Parameters ◽  
Ratio Test ◽  
Estimation Of Parameters ◽  
Flow Models ◽  
Car Following

Parameter identification of microscopic driving models is a difficult task. This is caused by the fact that parameters—such as reaction time, sensitivity to stimuli, etc.—are generally not directly observable from common traffic data, but also due to the lack of reliable statistical estimation techniques. This contribution puts forward a new approach to identifying parameters of car-following models. One of the main contributions of this article is that the proposed approach allows for joint estimation of parameters using different data sources, including prior information on parameter values (or the valid range of values). This is achieved by generalizing the maximum-likelihood estimation approach proposed by the authors in previous work. The approach allows for statistical analysis of the parameter estimates, including the standard error of the parameter estimates and the correlation of the estimates. Using the likelihood-ratio test, models of different complexity (defined by the number of model parameters) can be cross-compared. A nice property of this test is that it takes into account the number of parameters of a model as well as the performance. To illustrate the workings, the approach is applied to two car-following models using vehicle trajectories of a Dutch freeway collected from a helicopter, in combination with data collected with a driving simulator.

scholarly journals Accelerated Life Tests under Pareto-IV Lifetime Distribution: Real Data Application and Simulation Study

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1786 ◽  
Author(s):  
A. M. Abd El-Raheem ◽  
M. H. Abu-Moussa ◽  
Marwa M. Mohie El-Din ◽  
E. H. Hafez
Keyword(s):  
Simulation Study ◽  
Stress Test ◽  
Real Data ◽  
Accelerated Life Test ◽  
Maximum Likelihood Estimates ◽  
Cumulative Exposure ◽  
Exposure Model ◽  
Model Parameters ◽  
Data Set ◽  
Accelerated Life

In this article, a progressive-stress accelerated life test (ALT) that is based on progressive type-II censoring is studied. The cumulative exposure model is used when the lifetime of test units follows Pareto-IV distribution. Different estimates as the maximum likelihood estimates (MLEs) and Bayes estimates (BEs) for the model parameters are discussed. Bayesian estimates are derived while using the Tierney and Kadane (TK) approximation method and the importance sampling method. The asymptotic and bootstrap confidence intervals (CIs) of the parameters are constructed. A real data set is analyzed in order to clarify the methods proposed through this paper. Two types of the progressive-stress tests, the simple ramp-stress test and multiple ramp-stress test, are compared through the simulation study. Finally, some interesting conclusions are drawn.

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