• Journal of Applied Reliability
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• v.18 no.1
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• pp.8-19
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• 2018

Purpose: This study has developed the accelerated lifetime test method for smps for outdoor lighting LED through two factors of temperature and humidity. Methods: Acceleration condition was confirmed for each stress and model, and acceleration life test model was estimated according to acceleration condition. Results: As a result of confirming the accelerated life test model, in the case of humidity, acceleration was established only in the foreign products. Therefore, it is confirmed that the acceleration condition is insufficient. However, the estimated parameters for temperature are relatively constant. It is therefore suitable for power supply acceleration tests for outdoor lighting LEDs. Conclusion: The SMPS acceleration test for outdoor lighting LED can improve the availability of the product by developing an accelerated life test method that guarantees the reliability of the product.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1498-1499
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• 2007

In general, ALT can be used to expect the lifetime of electric machines and accelerated stress testing(AST) is used to evaluate the residual life of insulation system. In this paper, a method to design the accelerated life testing(ALT) for reliability qualification of electrical apparatus is represented.

• Journal of Applied Reliability
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• v.9 no.4
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• pp.319-329
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• 2009

The airbag module is an inflatable restraint system that inflates within 0.05 seconds automatically in a collision to protect the occupants. The airbag fabrics used in the module are required to have the good resilience and strength and also to have retained at least 80% of mechanical properties after using longer than 10 years. In this study, we develop an accelerated test method in order to predict the lifetimes of airbag. In this test, we select temperature and humidity as environmental stresses by analyzing the failure mechanisms of coated and uncoated nylon 66 fabrics. It is found that the degradation of airbag fabrics is effectively accelerated under the combined conditions of high temperature and humidity. Analyzing the results of the accelerated test, the lifetimes of airbag fabrics are predicted to be longer than 10 years.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.749-752
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• 2004

Unlike OLEDs, there is no lifetime testing procedure for TFTs. In this work, we have defined such a procedure and developed a method for the accelerated stress testing of TFT pixel circuits in a-Si AMOLED displays. The acceleration factors derived are based on high current and temperature stress, and can be used to significantly reduce the testing time required to guarantee a 20000-hour display backplane lifespan.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.315-319
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• 2004

This paper presents the integrity evaluation method of the windings in cast resin transformers using vertical thermal distribution analysis. The method is to compare the temperature distribution in a sound condition specimen with that in the failure condition specimen layer-shorted by accelerated testing. The temperature distribution was acquisited by a infrared thermography system, and the Arrhenius equation was adopted to the accelerated testing. The proposed method may be available to detect the failures in cast resin transformers.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.108-117
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• 1998

Testing and evaluation was carried out to certify quality assurance of localized engine parts using accelerated mission test method, which has been used to verify qualification or substantiation of the developed engine, improved engine components and engineering changed parts since 1976. Because AMT is not a familiarized testing for quality assurance of engine and localized engine parts in korea, through this testing and evaluation, it is presented the concepts, test procedures and evaluation method of AMT and is proposed the possibility of execution AMT, as a tool for qualification or substantiation test of a development engine or components.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.2
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• pp.145-149
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• 2003

We consider the estimation of failure rate and acceleration factor under type-I censoring without using acceleration model when testing is conducted in only one highly accelerated condition. Failure times of an item are assumed to be exponentially distributed. It is also assumed that the uncertainty about the acceleration factor, the failure time contraction ratio between accelerated condition and use condition, can be modeled by the uniform or gamma prior distribution of appropriate parameters. We respectively use Bayes and maximum likelihood approaches to estimate acceleration factor and failure rate in the use condition. An example is given to show how the method can be applied.

• Journal of the Korean institute of surface engineering
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• v.55 no.6
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• pp.383-389
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• 2022

Natural(outdoor) and accelerated(artificial) weathering tests were performed to investigate their influence on polycarbonate. The polycarbonate materials were prepared of various formulations divided into three batches, with existing, development materials1, development materials2, containing mixture of UV additives. Weathering tests were carried out as outdoor weathering(Seosan, South Korea) and accelerated weathering(xenon-arc), and the results analysis were evaluated based on yellow-index(YI), scanning electron microscope(SEM/EDS), energy dispersive x-ray spectroscopy(XRD), and gel permeation chromatography(GPC). Among the three materials, processing method development materials1 with UV stabilizer was excellent in weathering. This study can provide basic data for standardization of development and performance evaluation on livestock barn roof.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.73-81
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• 2012

PURPOSES : The purpose of this study is to select the proper sealing method and to see the performance of the saw and seal method for concrete rehabilitation based on accelerated pavement testings and lab tests. METHODS : Two accelerated pavement testings were conducted. One is to select proper sealing method of the asphalt joints and the other is to see the performance of the saw and seal method. Lab tests were conducted to select proper sealing method and a test section was constructed to see the field performance. RESULTS : The result of the first accelerated pavement testing indicated that the adhesive preformed sealants showed good performance when asphalt layer was rutted and in terms preventing from water infiltration. The second acceleration test indicated that the saw and seal method using the adhesive preformed sealant showed much better performance than the control. In the lab test bitumen, rubber and epoxy showed good performance as the adhesive. CONCLUSIONS : Saw and Seal method using the adhesive preformed sealant would markedly reduce the joint damage on the asphalt overlay.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.116-118
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• 2003

This paper describes a Accelerated Life Test (ALT) with the electrical contact erosion suitable to the evaluations of high-reliability and durability devices such as magnetic contactor. Recently, an electrical devices company was interested in accelerated life test (ALT), the product liability (PL) and the short-term testing model of electrical life test (ELT). In order to estimate a model for testing fee and period, need to the statistical analysis method with the acceleration factor(AF). Usually customer/manufacturer regard their device failure to the over-current or heavy duty condition, while devices view shape of contact erosion owing to operational duty problem. In this paper, additional method of evaluation estimated the operated cycles by weight of contact erosion with a used of regression analysis by MINITAB.