• 한국신뢰성학회지:신뢰성응용연구
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• 제6권1호
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• pp.63-91
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• 2006

According to the rapid development of science technologies, a life and development cycle of products are getting shorter and structures and functions become more complex so that the reliability requirement of customers is getting greater for components in the products. However, most domestic mechanical components are manufactured by small and medium-sized companies, who are manufacturing in poor economic and technical condition. Because of this, assessment technologies and equipment to predict and guarantee the reliability are very weak. For this reason, it is the fact that many customers neglect the domestic mechanical components which fail to win the reliability. Korean government has been trying to eliminate the problem by establishing 18 reliability assessment centers in 2000 and performing R-Mark certification promotion and constructions of the foundation for reliability assessment to rebuild the reliability on the domestic components and materials. Korea Institute of Machinery and Materials has been designated as a supervising organization for reliability assessment in the machinery filed for 5 years. In this paper, we would like to introduce effective and systematized 12 steps of reliability substantiation test on mechanical components with know-how we achieved during the period.

• 한국의류산업학회지
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• 제25권3호
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• pp.398-408
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• 2023

Smart clothing products can experience a decrease in performance and reliability due to various mechanical, biological, and chemical stress factors that occur throughout their life cycle. These issues can hinder consumer acceptance of the products. This study aims to enhance the reliability of smart clothing and facilitate quality control by analyzing and identifying the current status of international standardization for smart clothing and electronic textiles (e-textiles). The focus of this analysis was on the durability test methods in the use environment. Furthermore, similar standards published by different standardization organizations for durability tests were compared in depth. The study showed that a total of 27 international standards have been developed or are currently under development. The current standardization efforts mainly aim to develop functionality and durability test methods for smart clothing and e-textile products. A detailed comparison was made between two international standards (IEC 63023-204-1:2023 and AATCC TM210:2019) specifically in relation to the washing durability test method and the electrical resistance measurement standards (BS EN 16812:2016 vs AATCC EP13-2021), before and after the environmental exposure tests. Based on this comparison, several suggestions have been made and discussed for the future revision of these international standards.

• 한국신뢰성학회지:신뢰성응용연구
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• 제9권2호
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• pp.107-119
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• 2009

Reliability tests should be designed to verify whether reliability requirements are satisfied or not effectively and efficiently. The portion of reliability requirements that a reliability test scheme composed of different types of tests can cover is defined as test coverage in software engineering. For the cases of hardwares, to be effective, a reliability test scheme should enhance the test coverage. This study is to develop an evaluation method of test coverage for a reliability test scheme proposed for new products. Case studies are also given.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권3호
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• pp.145-148
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• 2015

The products to meet the requirement of are installed in nuclear power plant and the reliability target should be provided in the requirement. However, it is not easy to set a reliability target using quantitative analysis. The objective of this paper is to propose a method of reliability target setting considered warranty cost for process controller and then compare a reliability target with reliability analysis result.

• 한국신뢰성학회지:신뢰성응용연구
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• 제2권1호
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• pp.47-61
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• 2002

Experimental design has become one of the primary tools for achieving quality of manufactured products. However, this important tool has not been extensively used in achieving reliability. In this paper, we describe how experimental design can be used to achieve reliability.

• 산업경영시스템학회지
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• 제29권3호
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• pp.135-142
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• 2006

Engineers are always concerned with life cycle costs for making important economic decisions through engineering action like reliability of products. Decisions during the reliability growth development of products involve trade-offs between invested costs and its returns. In order to find minimal LCC containing the reliability improvement cost, production cost, repair and replacement costs, and holding cost of spare parts for failure items we suggest in this paper relationship between development cost and sustaining cost in values of growth parameter $\beta$ of AMSAA model. This model is applied to the reliability growth program based on AMSAA model during R&D phase, the warranty activities of items and the block replacement policy for maintenance of items in avionic equipment.

• International Journal of Reliability and Applications
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• 제4권2호
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• pp.79-95
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• 2003

Manufacturers collect and analyze field reliability data to enhance the quality and reliability of their products and to improve customer satisfaction. To reduce the data collecting and maintenance costs, the amount of data maintained for evaluating product quality and reliability should be minimized. With this in mind, some industrial companies assemble warranty databases by gathering data from different sources for a particular time period. This “marginal count failure data” does not provide (i) the number of failures by when the product entered service, (ii) the number of failures by product age, or (iii) information about the effects of the operating season or environment. This article describes a method for estimating age-based claim rates from marginal count failure data. It uses covariates to identify variations in claims relative to variables such as manufacturing characteristics, time of manufacture, operating season or environment. A Poisson model is presented, and the method is illustrated using warranty claims data for two electrical products.

• International Journal of Reliability and Applications
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• 제5권2호
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• pp.47-57
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• 2004

The market for used products is becoming more competitive and dealers of used products use warranty to promote sales as well as to provide assurance to customers. Offering warranty results in additional costs associated with warranty servicing. This cost can be reduced through actions such as overhaul and upgrade that improves the reliability of the item. This is worthwhile only if the cost of improvement is less than the reduction in the warranty servicing cost. This paper deals with two models to decide on the reliability improvement strategies for used items sold with FRW policy.

• International Journal of Reliability and Applications
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• 제4권4호
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• pp.157-170
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• 2003

In this paper we apply statistical reliability tools to manage and seek improvements in the strengths of medium density fiberboard (MDF). As a part of the MDF manufacturing process, the product undergoes destructive testing at various intervals to determine compliance with customer′s specifications. Workers perform these tests over sampled cross sections of the MDF panel to measure the internal bond (IB) in pounds per square inches until failure. We explore both graphically and statistically this "pressure-to-failure" of MDF. Also, we briefly comment on reducing sources of variability in the IB of MDF.

• 마이크로전자및패키징학회지
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• 제23권4호
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• pp.11-18
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• 2016

Today, wearable technology products are used in a wide range of consumer, healthcare, bio-medical, and industrial applications. The market for wearable technology products is expected to increase dramatically over the next several years. In addition, concerns for safety, performance and reliability of wearable products keep increasing and will be essential for widespread acceptance in the marketplace. Wearable smart devices, which are generally in contact with the human body and skin, are exposed to the risk of the electric shock, burn, and explosion. Therefore, the standardization of wearable devices in terms of human safety and reliability should be very important. Furthermore, the development of test method and test certification of the wearable products will be one of the key technology for mass production. Such standardization and certification will help consumers to choose the safest and best quality wearable devices and allow manufacturers to prove the safety and quality of their products, thereby helping them to gain a competitive technology. This paper discusses the current status of the wearable smart devices as well as the standardization and test certification applicable to wearable technology products.