• Journal of Applied Reliability
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• v.5 no.2
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• pp.203-207
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• 2005

• Journal of Applied Reliability
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• v.5 no.1
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• pp.143-148
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• 2005

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.4
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• pp.634-643
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• 2009

The aim of this study was investigating the consumers' and apparel firm worker's awareness and reliability of the environmental friendly textile materials. The subjects of the questionnaire survey were general consumers(n=235) and workers at Korean apparel firms(n=236). The questionnaire was developed to measure the awareness and reliability on nine environmental friendly textile materials. The results showed that general consumers had a higher reliability on the function of the environmental friendly materials but had a lower awareness than the workers at the apparel firms. Women and subjects, who experienced in purchasing the environmental friendly products, had higher awareness and reliability of the environmental friendly textile materials than others. The workers at apparel firms had higher awareness of the environmental friendly textile materials than the general consumers, but the reliability on the function of the materials was relatively low. The reliability and awareness differed by the firms' major products and their jobs. The workers at the children's clothing firms and sportswear firms had higher level of awareness about the environmental friendly textile than the workers at the casual-wear firms. The workers' awareness on environmental friendly textile materials was differentiated by their jobs. The product developers and material buyers had higher awareness on the environmental friendly textiles compare to the workers of the sales or marketing division. These results imply that promoting environmental friendly textile material to the sales person is needed in order to increase the sales volume of the products.

• Journal of Applied Reliability
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• v.6 no.2
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• pp.135-150
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• 2006

Rubber material properties and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. This paper discusses the failure mechanism and material tests were carried out to predict the useful lifetime of NBR and EPDM for compression motor, which is used in refrigerator component. The heat-aging process leads not only to mechanical properties change but also to chemical structure change so called degradation. In order to investigate the aging effects on the material properties, the accelerated test were carried out. The stress-strain curves were plotted from the results of the tensile test for virgin and heat-aged rubber specimens. The rubber specimens were heat-aged in an oven at the temperature ranging from $70^{\circ}C\;to\;100^{\circ}C$ for a period ranging from 1 to 180 days. Compression set results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the compression set test, several useful lifetime prediction equations for rubber material were proposed.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1734-1739
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• 2007

The materials characteristics and lifetime evaluation are very important in design procedure to assure the safety and reliability of rubber components. This paper discusses the failure mechanism and material test were carried out to predict the useful life of NBR and EPDM rubber mount for compression motor which is used in refrigerator. In order to investigate the heat-aging effects on the materials properties, stress-strain curve were obtained from the results of material tests. Compression set results changes as the threshold are used for assessment of useful life and the time were plotted against reciprocal of absolute temperature to give the Arrhenius plot.

• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.302-306
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• 2004

When we include environment side safety, environmental material's reliability technology and study for the application method, the evidence supporting the investment of R&D person and financial. Clearly, the most important task in electrical and electronics company's product soldering process the probability of heavy metals exclude is to identify the mechanisms by which they may take place. Therefore, this study emphasis on the application environmental material classification and reliability technology.

• Geomechanics and Engineering
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• v.17 no.6
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• pp.597-606
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• 2019

Ultrasonic Time-of-Flight Diffraction (TOFD) techniques are useful methods for non-destructive evaluation of fracture characteristics. This study focuses on the reliability and accuracy of ultrasonic diffraction methods to estimate the depth of rock fractures. The study material includes three different rock types; andesite, basalt and ignimbrite. Four different ultrasonic techniques were performed on these intact rocks. Artificial near-surface fracture depths were created in the laboratory by sawing. The reliability and accuracy of each technique was assessed by comparison of the repeated measurements at different path lengths along the rock surface. The standard error associated with the predictive equations is very small and their reliability and accuracy seem to be high enough to be utilized in estimating the depth of rock fractures. The performances of these techniques were re-evaluated after filling the artificial fractures with another material to simulate natural infills.

• Structural Engineering and Mechanics
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• v.3 no.1
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• pp.1-10
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• 1995

This study presents a methodology for the system reliability analysis of cracked structures with random material properties, which are modeled as random fields, and crack geometry under random static loads. The finite element method provides the computational framework to obtain the stress intensity solutions, and the first-order reliability method provides the basis for modeling and analysis of uncertainties. The ultimate structural system reliability is effectively evaluated by the stable configuration approach. Numerical examples are given for the case of random fracture toughness and load.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.102-102
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• 2009

The piezoelectric transformer have attracted a lot of interest in recent years because of their potential applications in electronic devices. However, their reliability in practical applications has not been systematically studied. For many piezoelectric materials, the temperature reliability are among the biggest concerns. This paper presents an experimental study of the piezoelectric transformers with the focus on its reliability under varying temperature conditions.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.5
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• pp.1058-1064
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• 2001

In this paper, the development of probability distribution estimation program for fatigue crack growth lives was summarize. The probability distribution estimation program of life was developed to increase the reliability of life estimation. In this study, it is considered that the cause of scatter in fatigue crack growth data is due to material inhomogeneity. The material resistance to fatigue crack growth is modelled as a spatial stochastic process, which varies randomly along the crack path. We developed the GUI program to estimate the probability distribution and reliability using the non-Gaussian stochastic process method. This program can be used for the reliability assessment.