• Journal of Applied Reliability
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• v.9 no.4
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• pp.331-341
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• 2009

PSA (Pressure Sensitive Adhesive) is used for various purposes in electronic appliances such as double-sided tape for fitting parts, product's name plate, and surface protecting film, and so forth. In several kinds of PSAs, this paper dealt with the failure analysis of PET (Polyethylene Terephthalate) acrylic adhesive tapes. The causes of interface failure were investigated through the test of adhesive strength, thickness, and structure. And test standard methods to prevent recurrences were established.

• Journal of Applied Reliability
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• v.6 no.1
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• pp.93-103
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• 2006

Basic function of calorifier system is to supply warm water to the vessel. The heater used in the calorifier system plays a very important role in its reliability. The failure mechanism of heater are compared with accelerated life test. The main cause of failed heater is pitting corrosion occurred between the surface of heater and spacer. To prevent the corrosion failure from heater, material of spacer replaces metal(SUS 304) with polymer (Acryl). The life of redesigned heater can guarantee 2.47years of B10 life under the worst condition.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.766-770
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• 2011

In this paper, we describe the failure analysis and representation test method that applied high frequency transformer for SMPS through analysing insulation resistance, frequency characteristic, CT analysis, Q-factor atc. And we study the judgement method that a high frequency transformer affects to other beside parts in different condition or environment. According to this method, we devise a plan for the field failure prevent and propose the securing product reliability of high frequency transformer.

• Journal of Applied Reliability
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• v.17 no.4
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• pp.343-354
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• 2017

Purpose: This paper evaluates the reliability of tapered grid couplings and presents test results through performance and life tests. Methods: The performance and life test method were presented by analyzing the failure modes for the tapered grid coupling. Zero failure test time was calculated to evaluate the reliability of tapered grid couplings and the test was performed under accelerated conditions. The nondestructive test and wear analysis using weighing were also carried out to check the failure modes of the field conditions. Conclusion: This study can be provided to improve the product reliability through failure analysis of a tapered grid coupling. The performance test results of before and after the accelerated life test were presented to confirm the improved reliability of the tapered grid coupling.

• Corrosion Science and Technology
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• v.20 no.5
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• pp.242-248
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• 2021

Unforeseen failures of boilers in power plants may affect the continuation of electricity generation. Main failures in boilers are influenced by the tube material, tube position, boiler service temperature and pressure, and chemical composition of the feed water and coal. This investigation was intended to find answers on the causes and mechanism of failure of the fire-side boiler water-wall tubes, due to perforation and corrosion. The tube conformed to the material requirements in terms of its chemical composition and hardness. Microscopic examination showed ferrite and pearlite indicating no changes in its microstructure due to the temperature variation. SEM test showed a single layer and homogenous film density particularly on the area far from perforation. However, layers of corrosion product were formed on the nearby perforation area. EDX showed that there were Na, Ca, S, and O elements on the failed surface. XRD indicated the presence of Fe₂O₃ oxide. The failure mechanism was identified as a result of significant localized wall thinning of the boiler water wall-tube due to oxidation.

• IEMEK Journal of Embedded Systems and Applications
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• v.19 no.1
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• pp.57-64
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• 2024

In the industrial field, robots are used to increase productivity by replacing labors with dangerous, difficult, and hard tasks. However, failures of individual industrial robots in the entire production process may cause product defects or malfunctions, and may cause dangerous disasters in the case of manufacturing parts used in automobiles and aircrafts. Although requirements for early diagnosis of industrial robot failures are steadily increasing, there are many limitations in early detection. This paper introduces methods for diagnosing robot failures using sound-based data and deep learning. This paper also analyzes, compares, and evaluates the performance of failure diagnosis using various deep learning technologies. Furthermore, in order to improve the performance of the fault diagnosis system using deep learning technology, we propose a method to increase the accuracy of fault diagnosis based on an inference window. When adopting the inference window of deep learning, the accuracy of the failure diagnosis was increased up to 94%.

• Journal of the Korean Society of Food Culture
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• v.33 no.2
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• pp.199-205
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• 2018

This study has utilized the Quality Function Deployment (QFD) technique in order to plan the tangible (menu) and intangible (service) product of dumpling restaurant. The engineering characteristics of tangible products were classified into product planning, purchase management, production management, and information management based on the production system of foodservice. The engineering characteristics of intangible products were also classified into physical evidence, human interaction, and pre-communication based on the service operation and delivery system. As a result of analyzing the QFD, it was found that the customer hope the hygiene factor and response factor to be improved. It is analyzed that product planning, information management, and production management should be improved first in terms of engineering characteristics considering consumer needs. In the future, by utilizing the systematic product development process that the requirements of tangible and intangible product consumers are converted to the engineering characteristics, the development of competitive product within the market will be possible, and furthermore it is expected to be useful for reducing the unnecessary time and design costs due to failure of product development.

• Journal of Korean Society for Quality Management
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• v.26 no.1
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• pp.27-47
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• 1998

The primary objective of this research is to provide the basis of total quality management policies by reviewing previous studies which investigated effective ways to reduce product liability exposure. Specifically, the present study intends (1) to examine recent patterns and trends of product liability law in OECD countries, (2) to propose quality management policies for preventing product liability litigations, and (3) to guide the proper implementation process of ISO 9000 certification programs. The survey results show that the shift from a negligence law theory to strict liability is evident in most countries. The trend has led to make it easier for consumers to bring product liability lawsuits. Furthermore, the damage awards won by consumers have been drastically increasing. To minimize product liability exposure, manufactures should reflect comprehensive product safety concepts in establishing total quality management policies. Cooperative activities are also required between departments in companies to reach safe and satisfactory quality level. These quality management activities should be performed consistently during the total product life cycle. Failure to comply with the ISO 9000 certifications might be used as an evidence of negligence or as evidence of a design defect in court. Previous lawsuit cases, however, reveal that ISO 9001-9003 registration process alone is not sufficient in terms of product liability pervention perspectives. Therefore, manufactures should take into account ISO 9004 before implementing any other section of ISO 9000 standards.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.331-333
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• 2007

Product reliability is important to quality and competitiveness. Much management and engineering efforts go into evaluating reliability, assessing new designs and changes of manufacturing processes, identifying cause of failure. Major methods are based on environmental test. In this study, we analysis the environmental test data of the electrical component, unit, set. These data were gathered for 7 years.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.59
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• pp.97-103
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• 2000

This study considers the design of life test sampling inspection plans by attributes for failure rate level qualification at selected confidence level. The lifetime distribution of products is assumed to be exponential. MIL-STD-690C and KS C 6032 standards provide this procedures. But these procedures have some questions to apply in the field. The cost of test and confidence level($1-{\beta}$ risk) are the problem between supplier and user. So, we suggest that the optimal life test sampling inspection plans using expected cost model considering product cost, capability, environmental test cost, etc.