• 한국의류산업학회지
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• 제14권3호
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• pp.430-437
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• 2012

This study analyzed the sensibility of eco-friendly fabrics for college students and investigated their attitude on environmental problems, trust reliability onto eco-apparel products, and their purchase state. We tested 6 eco-friendly fabrics (recycled polyester, organic cotton, green tea, charcoal, bamboo, and nettle) through a survey using the Likert scale of 12 polar sensibility words. Most fabrics showed feelings that were smooth, natural, female, and country these were followed by fashion, cheap, functional, sustainable, warm, and vintage. In addition, nettle fabric showed 'rough' feeling, and recycled polyester fabric showed an 'artificial' feeling. Correspondence analysis showed the distance and direction between fabric types and sensibility words with a 2D diagram where the X axis was named with 'Soft <-> Hard' and Y axis was with 'Environmental <-> Manmade' to represent the relationship between fabric types and the sensibility words. According to the results of the multiple regression analysis, the cognition level of the consumer for environmental problems was found to be the most influential variable on the loyalty purchase of eco-friendly products; however, the trust reliability level of consumer onto eco-friendly apparel products was found to be the most influential variable on the conditional purchase of eco-friendly apparel products.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.320-323
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• 2005

This paper discusses heat problem of IC, which composes the electronic instruments, to guarantee reliability of electronic instruments. And also proposes the unified equivalent model for various electronic instrument products to guarantee reliability and life of its parts. Because electronic instruments are down sizing and operated with high frequency, the internal temperature of electronic instruments is rising steadily. The internal temperature of the electronic instruments gives a big effect to electronic instrument's reliability and life. The semiconductor parts are the representative heat generation parts because of its complicated function, high frequency and high density. Consequently, guaranteeing reliability and life of electronic semiconductor is the important start point in securing the reliability and life of the electronic instrument product. Unfortunately, there are many factors, which affect heat dissipation efficiency. The heat dissipation efficiency follows the environment where the electronic instrument products are used. Therefore it is very difficult to define reliability and life of the electronic manufactures. Electronic instrument products are composed of printed circuit board (PCB), integrated circuit (IC), resistance, and capacitor and so on. And there are superposed thermal resistances, because the parts are arrayed on the printed circuit board (PCB), Therefore the total thermal resistance is variable. Consequently it cannot have same thermal model for each electronic instrument products. In the next part, we propose the unified equivalent model for various electronic instruments. And using the proposed equivalent model proofs the method for analysis reliability of electronic parts.

• International Journal of Reliability and Applications
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• 제7권1호
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• pp.71-77
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• 2006

The market for second hand products has been growing for a variety of reasons (e.g., new products appearing at a faster rate and the expected life of products increasing due to rapid advances in technology). The demand for warranties for second-hand products has been growing along with the growth of the market for second-hand products. Warranty for new products (consumer durables, industrial and commercial, and specialized defense products) has received a lot of attention. In contrast, warranties for second-hand product have received very little attention. Often, dealers of second-hand product such as cars offer 2D-warranties (Year and Kilometers). The expected warranty cost associated with a second-hand product for 2D-Policies is a function of the age of the item and its usage (as it affects failures over the warranty period), the warranty terms and the servicing strategy used by the dealer. This paper deals with development of models for warranty cost analysis along with the decision on sale price and warranty cover for 2D-Warranty policies associated with sale of second-hand products.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2001년도 정기학술대회
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• pp.289-289
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• 2001

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

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권4호
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• pp.220-224
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• 2014

A Bayesian zero-failure reliability demonstration test method for products with Weibull lifetime distribution is presented. Inverted gamma prior distribution for the scale parameter of the Weibull distribution is used to design the Bayesian test plan and selecting a prior distribution using a prior test information is discussed. A test procedure with zero-failure acceptance criterion is developed that guarantee specified reliability of a product with given confidence level. An example is provided to illustrate the use of the developed Bayesian reliability demonstration test method.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권2호
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• pp.91-103
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• 2012

Tubular markers for road safety facilities are used to lead the driver's sight line and separate the lanes on the road. Such tubular markers are usually installed on the road and frequently hit by vehicles, they are accordingly requested to assure the product durability. The traditional evaluation method of tubular markers include only quality tests of the material properties. However, most of consuming agencies in charge of road management at fields have proposed problems on long-term performance of the products hit by vehicles under various weather conditions. Therefore, the objectives of this study are to develop the reliability test methods and equipments to simulate the product failures of tubular markers due to vehicle collision and wheel compression and the delamination and discoloration of reflection sheets attached on the surface of the products under high and low temperatures.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.473-476
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• 2000

The network reliability is to be computed in terms of the terminal reliability. The computation of a termini reliability is started with a Boolean sum of products expression corresponding to simple paths of the pair of nodes. This expression is then transformed into another equivalent expression to be a Disjoint Sum of Products form. But this computaion of the terminal reliability obviously does not consider the communication between any other nodes but for the source and the sink. In this paper, we derive the overall network reliability which is the probability of communication that each node in the network communicates with all other remaining nodes. For this, we propose a method to make the SOP disjoint for deriving the network reliability expression from the system success expression using the modified Sheinman's method and modified BDD method.

• International Journal of Reliability and Applications
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• 제9권1호
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• pp.53-70
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• 2008

In this paper, we discuss the plethora of uses for the software package R, and focus specifically on its helpful applications in reliability data analyses. Examples are presented; including the R coding protocol, R code, and plots for various statistical as well as reliability analyses. We explore Kaplan-Meier estimates and maximum likelihood estimation for distributions including the Weibull. Finally, we discuss future applications of R, and usages of quantile regression in reliability.

• 산업경영시스템학회지
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• 제28권1호
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• pp.49-54
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• 2005

Recently, the reliability are applied for many industrial products, and many products are required to guarantee in quality and in performance. The purpose of this paper is to present some of reliability prediction methodologies using failure rate database for machinery parts that are applicable to machine tools. VDI Turret, which is core component of the NC Lathe, was chosen as the target of the reliability prediction. The results of reliability prediction has shown the failure rate, MTBF(Mean Time Between Failure), and reliability of the VDI Turret. It is expected that proposed methodologies will be applicable to prediction of reliability for other components of machine tools.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권1호
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• pp.48-55
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• 2016

Purpose: The purpose of this study is to identify the object-oriented metrics which have strong impact on the reliability and fault-proneness of software products. The reliability and fault-proneness of software product is closely related to the design properties of class diagrams such as coupling between objects and depth of inheritance tree. Methods: This study has empirically validated the object-oriented metrics to determine which metrics are the best to predict fault-proneness. We have tested the metrics using logistic regressions and artificial neural networks. The results are then compared and validated by ROC curves. Results: The artificial neural network models show better results in sensitivity, specificity and correctness than logistic regression models. Among object-oriented metrics, several metrics can estimate the fault-proneness better. The metrics are CBO (coupling between objects), DIT (depth of inheritance), LCOM (lack of cohesive methods), RFC (response for class). In addition to the object-oriented metrics, LOC (lines of code) metric has also proven to be a good factor for determining fault-proneness of software products. Conclusion: In order to develop fault-free and reliable software products on time and within budget, assuring quality of initial phases of software development processes is crucial. Since object-oriented metrics can be measured in the early phases, it is important to make sure the key metrics of software design as good as possible.